JP2014089258A - Magenta toner for electrostatic charge image development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To find a method of selecting impurity on the surface of toner related to image defects, and to provide a toner having high reproduction stability and capable of suppressing image defects with the selection method.SOLUTION: In the analysis of the surface elemental composition of a toner for electrostatic charge image development with an X-ray photoelectron spectroscopic device (XPS), the amounts of sulfur atoms and nitrogen atoms are found to satisfy a specific numerical relationship relative to the amount of carbon atoms, so as to provide a toner for electrostatic charge image development having high reproduction stability and capable of providing excellent image quality.

Description

  The present invention relates to an electrostatic charge developing toner used in electrophotography, electrostatic photography and the like and a toner cartridge using the same.

  In general, an electrophotographic method forms an electrostatic latent image on a photoconductive photoreceptor by various methods, and then visualizes the latent image using an electrostatic charge developing toner (hereinafter abbreviated as “toner”). Thereafter, the method includes a step of transferring the toner visible image onto a transfer material such as paper and fixing the toner image by heating or pressurizing. Various methods are known as these steps, and those suitable for each image forming process are employed.

As the toner, a two-component toner composed of a carrier and a toner and a one-component toner (magnetic toner, non-magnetic toner) that does not require a carrier are known. In the case of non-magnetic toner, the binder resin is used as the main component. In the case of magnetic toner, the binder resin and the magnetic powder are used as the main components. In addition to the binder resin, a colorant (pigment), a charge control agent, wax, etc. Is dispersed and contained.
In the production of the toner, high quality and reproducibility are required, but the amount of surface impurities of the produced toner also fluctuates due to fluctuations in production (for example, fluctuations in the production temperature and humidity environment).

Therefore, specifically, it has been necessary to find out which toner surface impurities cause what kind of image defects.
Patent Document 1 discloses that, for the toner surface state, the coverage of the colorant molecules on the toner surface by XPS measurement is preferably 1.5 to 15 atomic%.

JP 2003-262985 A

However, as a result of examination by the present inventor, an image defect occurred within the range disclosed in Patent Document 1, which was insufficient from the viewpoint of reproduction stability.
An object of the present invention is to find a toner surface impurity selection method related to image defects, and to provide a toner that has high reproduction stability and can suppress image defects by the selection method.

As a result of intensive studies in view of the above-mentioned problems, the present inventors have confirmed that the electrostatic charge image developing toner satisfies a specific numerical relationship in surface elemental composition analysis by an X-ray photoelectron spectrometer (hereinafter referred to as XPS). The inventors have found a toner for developing an electrostatic charge that has high performance and can obtain excellent image quality. That is, the gist of the present invention is as follows.
1. A toner for developing an electrostatic charge image containing at least a colorant and a binder resin, wherein the ratio of sulfur atom to carbon atom by SPS by surface element composition analysis by XPS is N / C and the ratio of nitrogen atom is N / C A toner for developing electrostatic images, wherein the product of S / C and N / C satisfies the following formula (1):

S / C · N / C ≦ 6.6 × 10 ⁻⁶ (1)
2. The S / C value is 0.7 × 10 ⁻³ or less. The toner for developing an electrostatic charge image according to 1.
3. ^1. The residual surfactant amount on the toner surface detected by ¹ H-NMR is 280 ppm or less. Or 2. The toner for developing an electrostatic charge image according to 1.

  According to the present invention, by selecting a toner for developing an electrostatic image that satisfies a specific numerical relationship in the surface elemental composition analysis by XPS, it is possible to suppress the occurrence of image defects, and to detect in advance the presence or absence of image defects, In addition, there is an effect that feedback is possible for optimization and stabilization to future manufacturing conditions.

Hereinafter, the present invention will be described. However, the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented.
The method for producing the electrostatic image developing toner of the present invention (hereinafter sometimes abbreviated as “developing toner” or “toner”) is not particularly limited. In the manufacturing method, the configuration described below may be employed.

<Toner for electrostatic image development of the present invention and selection method>
The electrostatic charge developing toner of the present invention has a ratio of S / C and N / C, where S / C is the ratio of sulfur atoms to carbon atoms and N / C is the ratio of nitrogen atoms by surface elemental composition analysis by XPS. The product satisfies the following formula (1).
S / C · N / C ≦ 6.6 × 10 ⁻⁶ (1)
Here, it is considered that S / C depends on the abundance of molecules containing sulfur atoms present on the toner surface used during toner production. The detailed reason is not clear, but if there is a strong electron-attracting compound containing sulfur atoms on the toner surface, water molecules are arranged around it to form a toner surface charge leakage point, and to improve the toner chargeability. It is presumed to cause problems such as weakening, worse paper fog, increased consumption, and increased in-flight scattering.

Although the compound containing a sulfur atom is not specifically limited, For example, existence of surfactant containing a sulfonic acid, a sulfonic acid metal salt, a sulfonic acid organic salt, and these derivatives is estimated. In addition, a charge control agent, a charge control resin, and the like that are composed of a compound containing an electron-withdrawing functional group containing a sulfur atom are also considered as constituent elements.
N / C is considered to depend on the amount of molecules containing nitrogen atoms present on the toner surface. Although the detailed reason is not clear, if there is a relatively strong electron-donating compound containing a nitrogen atom on the toner surface, a water molecule or electron-withdrawing compound is placed around the toner surface, causing the toner surface charge leakage point. It is presumed that the chargeability of the toner is weakened, causing problems such as deterioration of paper fogging, an increase in consumption, and an increase in in-flight scattering.

Although the compound containing a nitrogen atom is not specifically limited, It is not specified, For example, existence of the pigment containing quinacridone, naphthol, and these derivatives is estimated. Further, a charge control agent, a charge control resin, and the like that are composed of a compound containing an electron donating functional group containing a nitrogen atom are also considered as constituent elements.
In the toner of the present invention, the S / C value is not particularly limited as long as it does not significantly impair the effects of the present invention, but the upper limit is usually 0.7 × 10 ⁻³ or less, preferably 0. .6 × 10 ⁻³ or less. On the other hand, the lower limit is not particularly provided because it is preferable that no sulfur atom exists on the toner surface, but is 0.0 or more. If the S / C is too high, it may cause an increase in image fogging, which may adversely increase the amount of collected toner.

In the toner of the present invention, the value of N / C is not particularly limited as long as the effect of the present invention is not significantly impaired, but the upper limit is usually 9 × 10 ⁻³ or less, preferably 8 × 10. ⁻³ or less, more preferably 7 × 10 ⁻³ or less. On the other hand, the lower limit is not particularly provided because it is preferable that no nitrogen atoms exist on the toner surface, but is 0.0 or more. If N / C is too high, image fogging may increase.

Not only when both S / C and N / C are high, but when one is low and the other is high, image defects may occur, and the relational expression between S / C and N / C holds.
The ratio S / C of the sulfur atom to the carbon atom and the ratio N / C of the nitrogen atom to the carbon atom defined in the present invention are the amounts of the carbon atom, the sulfur atom and the nitrogen atom by the surface elemental composition analysis by XPS described in detail below. It is defined by measuring

First, the sample is filled in the hole of the sample stage, lightly pressed and smoothed with medicine wrapping paper, and then covered with a molybdenum mask having a 1 mm diameter pinhole and screwed to prepare the sample.
The analysis conditions are as follows.
Model name: Quantum2000 manufactured by PHI
X-ray source: Monochromatic Al-Kα
Output: 17kV-30W (X-ray generation area 170μmφ)
Neutralizing gun: electron gun 2μA, ion gun 1V
Spectroscopic system: Path energy
187.85 eV @ wide spectrum
93.90 eV @ narrow spectrum (N1s, Na1s, S2p, Cl2p)
58.70 eV @ narrow spectrum (C1s, O1s, Si2p, Ti2p)
Analysis area: 300 μm
Extraction angle: 45 ° (from surface)

Further, it is considered that the value of S / C depends on the amount of the residual surfactant on the toner surface and the amount of a resin (binder, charge control resin, etc.) having a functional group containing elemental sulfur. Further, the amount of the residual surfactant on the toner surface and the amount of the resin having a functional group containing sulfur element can be detected by H ¹ -NMR, and the S / C value and N / C obtained from the analysis by XPS can be detected. By selecting the toner using the detected amount data of the remaining surfactant and sulfur-containing atom resin by C and H ¹ -NMR, the effect of the present invention can be exhibited more remarkably.
In the present invention, in order to explain the detection by H ¹ -NMR in more detail, the surfactant will be described in detail below.
NMR analysis was performed according to the following procedure.

<Preparation of sample 1>
First, 20 g of toner and 100 ml of methanol are placed in a 200 ml beaker and stirred for 5 minutes with a stirrer. Let stand for 10 min and suction filter with quantitative filter paper (5A). The filtrate is suction filtered with a 1 μm membrane filter, and the filtrate is recovered.
Next, after standing and drying on an evaporating dish for about 90 hours, the precipitate is collected in a vial with 15 ml of methanol and dried by nitrogen blowing to obtain Sample 1.

<Measurement of NMR>
1.8 g of deuterated methanol containing 28 mg of maleic acid is added to and dissolved in the vial containing Sample 1 as an internal standard substance. The solution is placed in a 5 mmφ NMR sample tube to a height of 4 cm, and the lid is closed and sealed. Using JEOL NMR ECS400, ¹ H-NMR was measured at a flip angle of 45 °, a pulse repetition time of 40 seconds (including a Relaxation Delay of 30 seconds), a total of 16 times, and a temperature of 25 ° C.

In the toner of the present invention, the value of the surface residual surfactant amount is not particularly limited as long as the effect of the present invention is not significantly impaired, but the upper limit is usually 280 ppm or less, preferably 260 ppm or less. . On the other hand, the lower limit is usually 0.0 or more because it is preferable that no sulfur atom exists on the toner surface. However, it takes a lot of time and cost to reduce the surface-active surfactant, which is a trade-off between the efficiency of toner production and cost reduction. For example, in the production of toner base particles by a wet method, it is necessary to increase the cleaning time and increase the cleaning flow rate in the toner base particle cleaning step. Also from this viewpoint, it is necessary to set an upper limit of the amount of the surfactant remaining on the surface. If the amount of the surfactant remaining on the surface is too high, it may cause an increase in image fogging, which may adversely affect the amount of recovered toner.

The toner of the present invention can be obtained by conducting the above surface elemental composition analysis by XPS and selecting a toner satisfying the above formula (1). In addition, if necessary, by selecting a toner that simultaneously satisfies that the amount of surfactant is 280 ppm or less when the amount of surfactant remaining on the toner surface is analyzed by ¹ H-NMR by methanol extraction. can get.

<Configuration of toner>
The components constituting the toner of the present invention include a binder resin, a colorant (pigment), an internal additive such as a charge control agent and wax, an external additive, and the like as necessary.
As binder resin, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene acrylic resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, polyethylene resin, silicon resin, butyral resin Terpene resin, polyol resin and the like.
A known colorant can be arbitrarily used as the colorant. Specific examples of the colorant include known dyes such as quinacridone pigments, monoazo pigments, and perylene pigments, which can be used alone or in combination. In particular, it is preferable to use quinacridone or a monoazo dye / pigment. The colorant is preferably used so as to be 3 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymer primary particles.

  A charge control agent may be used for the toner, and when a charge control agent is used, any known one can be used alone or in combination. For example, a quaternary ammonium salt as a positively chargeable charge control agent can be used. , Basic and electron-donating metal materials, metal chelates as negative charge control agents, metal salts of organic acids, metal-containing dyes, nigrosine dyes, amide group-containing compounds, phenol compounds, naphthol compounds and the like Metal salts, urethane bond-containing compounds, and acidic or electron-withdrawing organic substances.

  In addition, a charge control agent that is colorless or light in color and does not impair the color tone of the toner can be used. For example, a quaternary ammonium salt compound is used as a positive charge control agent, and salicylic acid or alkyl is used as a negative charge control agent. Metal salts and metal complexes of salicylic acid with chromium, zinc, aluminum, etc., metal salts of benzylic acid, metal complexes, amide compounds, phenol compounds, naphthol compounds, phenolamide compounds, 4,4′-methylenebis [2- [N Hydroxynaphthalene compounds such as-(4-chlorophenyl) amide] -3-hydroxynaphthalene] are preferred.

The toner of the present invention can contain a wax for imparting releasability. Any wax can be used as long as it has releasability. Specifically, for example, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene and copolymer polyethylene; paraffin wax; ester waxes having a long-chain aliphatic group such as behenyl behenate, montanate ester, stearyl stearate Plant-based waxes such as hydrogenated castor oil and carnauba wax; ketones having long-chain alkyl groups such as distearyl ketone; silicones having alkyl groups; higher fatty acids such as stearic acid; long-chain fatty alcohols such as eicosanol; glycerin; Examples include carboxylic acid esters or partial esters of polyhydric alcohols obtained from polyhydric alcohols such as pentaerythritol and long chain fatty acids; higher fatty acid amides such as oleic acid amide and stearic acid amide; low molecular weight polyesters.

  Among these waxes, in order to improve fixability, the wax preferably has a melting point of 30 ° C. or higher, more preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher. Moreover, the thing of 100 degrees C or less is preferable, the thing of 90 degrees C or less is more preferable, and 80 degrees C or less is especially preferable. A wax having a melting point within the above range exhibits excellent fixability at low temperatures without causing stickiness or the like.

  As the wax compound species, higher fatty acid ester waxes are preferable. Specific examples of the higher fatty acid ester wax include, for example, behenyl behenate, stearyl stearate, stearate ester of pentaerythritol, glyceride montanate, and the like, and fatty acids having 15 to 30 carbon atoms and 1 to 5 valent alcohols. The esters are preferred. Moreover, as an alcohol component which comprises ester, a C1-C30 thing is preferable in the case of monohydric alcohol, and a C3-C10 thing is preferable in the case of a polyhydric alcohol.

  The waxes may be used alone or in combination. Further, the melting point of the wax compound can be appropriately selected depending on the fixing temperature for fixing the toner. The amount of the wax is preferably 1 part by mass or more per 100 parts by mass of the toner, more preferably 2 parts by mass or more, and further preferably 5 parts by mass or more. 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 it is too high, the anti-blocking property may be insufficient or the wax may leak from the toner and contaminate the device. There is a case.

  Examples of the external additive include inorganic particles such as silica, aluminum oxide (alumina), zinc oxide, tin oxide, barium titanate, and strontium titanate; organic acid salt particles such as zinc stearate and calcium stearate; methacrylate ester Examples thereof include organic resin particles such as polymer particles, acrylic acid ester polymer particles, styrene-methacrylic acid ester copolymer particles, and styrene-acrylic acid ester copolymer particles.

[Method for producing toner for developing electrostatic image]
Next, a method for producing an electrostatic charge image developing toner according to the present invention will be described.
[Manufacturing process of toner base particles]
The method for producing the toner of the present invention is not limited, and the toner base particles can be produced by a conventionally used method such as a pulverization method, a wet method, a method of sphering the toner by a mechanical impact force, heat treatment, or the like. Examples of the wet method include a suspension polymerization method, an emulsion polymerization aggregation method, a dissolution suspension method, and an ester extension method.

<Crushing method>
A method for producing toner mother particles by a pulverization method will be described. In the case of the pulverization method, a predetermined amount of a binder resin, a colorant, and other components as required are mixed and mixed. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauter mixer.

Next, each component is blended, and the mixed toner raw material is melt-kneaded to melt the resins and disperse the colorant and the like therein. In the melt-kneading step, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. For the kneading machine, a single screw or twin screw extruder is used. For example, KTK type twin screw extruder manufactured by Kobe Steel, TE equipment manufactured by Toshiba Machine Co., Ltd.
Examples include an M-type twin screw extruder, a twin screw extruder manufactured by Kay Sea Kay, and a co-kneader manufactured by Buss. Furthermore, the colored resin composition obtained by melt-kneading the toner raw material is rolled by a two-roll roll after melt-kneading, and then cooled through a cooling step of cooling by water cooling or the like.

  The cooled product of the colored resin composition obtained above is then pulverized to a desired particle size in a pulverization step. In the pulverization step, first, coarse pulverization is performed with a crusher, a hammer mill, a feather mill or the like, and further, pulverization is performed with a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nisshin Engineering Co., Ltd. or the like. After that, if necessary, the particles are classified using a classifier such as an inertia classification type elbow jet (manufactured by Nippon Steel Mining Co., Ltd.) or a centrifugal classification type turboplex (manufactured by Hosokawa Micron Co., Ltd.). obtain. Further, the toner may be spheroidized using a conventionally used method.

<Wet method>
In the present invention, it is preferable to apply a wet method for producing toner base particles in a wet medium. Examples of the wet method include suspension polymerization method, emulsion polymerization aggregation method, dissolution suspension method and the like, and any method may be used. Is preferred.

(Suspension polymerization method)
In the suspension polymerization method, a colorant, a polymerization initiator, and, if necessary, additives such as wax, polar resin, charge control agent and cross-linking agent are added to the binder resin monomer and dissolved or dispersed uniformly. A monomer composition is prepared. This monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer and the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, polymerization is performed by stirring to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. By collecting these by washing and filtration, toner mother particles can be obtained.

(Dissolution suspension method)
In the dissolution suspension method, a solution phase obtained by dissolving a binder resin in an organic solvent and adding a colorant or the like is dispersed by a mechanical shear force in an aqueous phase containing a dispersant and the like to form droplets. The toner base particles can be obtained by forming and removing the organic solvent from the droplets.
(Emulsion polymerization aggregation method)
In the emulsion polymerization aggregation method, polymer primary particles of a binder resin monomer obtained by an emulsion polymerization step, a colorant dispersion, a wax dispersion, etc. are prepared, and these are dispersed in an aqueous medium and heated. By performing the agglomeration step and further the aging step. These can be collected by washing and filtration to obtain toner base particles. Next, the toner base particles go through a drying process. Further, if necessary, an external additive or the like can be added to the toner base particles to obtain a toner.

  The emulsion polymerization aggregation method will be described in more detail. In the emulsion polymerization step, a polymerizable monomer that becomes a binder resin is usually polymerized in an aqueous medium in the presence of an emulsifier. At this time, each monomer is used to supply the polymerizable monomer to the reaction system. The body may be added separately, or a plurality of types of monomers may be mixed in advance and added simultaneously. The monomer may be added as it is, or may be added as an emulsion mixed and adjusted in advance with water or an emulsifier.

As the acidic monomer, a polymerizable monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, 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 vinylbenzenesulfonamide. Examples of the basic monomer include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocyclic-containing polymerizable monomers such as vinylpyridine and vinylpyrrolidone, dimethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc. And (meth) acrylic acid ester having an amino group. These acidic monomers and basic monomers may be used singly or as a mixture of a plurality of types, and may exist as a salt with a counter ion. Among these, it is preferable to use an acidic monomer, more preferably acrylic acid and / or methacrylic acid.

The total amount of the acidic monomer and the basic monomer in 100 parts by mass of the total polymerizable monomers constituting the binder resin is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass. More preferably, it is 1.0 part by mass or more, preferably 10 parts by mass or less, more preferably 5 parts by mass or less.
Examples of other polymerizable monomers include styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, and pn-nonylstyrene, methyl acrylate, 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 methacrylate -Methacrylic acid esters such as butyl, isobutyl methacrylate, hydroxyethyl methacrylate, 2-ethylhexyl methacrylate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylic De, N, N-dibutyl acrylamide, and the like, the polymerizable monomer may be used singly, or may be used in combination.

The electrostatic charge developing toner of the present invention comprises a styrene resin as a binder resin, which is a polymer of a styrene monomer alone or a polymer of a styrene monomer and another monomer.
Furthermore, when the binder resin is a cross-linked resin, a polyfunctional monomer having radical polymerizability is used together with the above polymerizable monomer, for example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, Examples include diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, and diallyl phthalate. It is also possible to use a polymerizable monomer having a reactive group in a pendant group, such as glycidyl methacrylate, methylol acrylamide, acrolein and the like. Among these, radically polymerizable bifunctional polymerizable monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable. These polyfunctional polymerizable monomers may be used alone or as a mixture of plural kinds.
When the binder resin is polymerized by emulsion polymerization, a known surfactant can be used as an emulsifier. As the surfactant, one or more surfactants selected from cationic surfactants, anionic surfactants, and nonionic surfactants 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 examples of the anionic surfactant include And fatty acid soap such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate and the like. Nonionic surfactants include, for example, polyoxyethylene dodecyl ether, polyoxyethylene monohexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose Etc.

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, these emulsifiers can be used as protective colloids, for example, one or more of partially or completely saponified polyvinyl alcohols such as polyvinyl alcohol and cellulose derivatives such as hydroxyethyl cellulose.
The volume average particle diameter of the polymer primary particles obtained by emulsion polymerization is preferably 0.02 μm or more, more preferably 0.05 μm or more, still more preferably 0.1 μm or more, preferably 3 μm or less, more preferably 2 μm. Hereinafter, it is more preferably 1 μm or less. If the particle size is too small, it may be difficult to control the aggregation rate in the aggregation process. If it is too large, the particle size of the toner particles obtained by aggregation tends to be large, and a toner having the target particle size is obtained. May be difficult.

  In the emulsion polymerization suspension method, known polymerization initiators can be used as necessary, and the polymerization initiators can be used alone or in combination of two or more. For example, persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, and the like, and redox initiators combining these persulfates as a component with a reducing agent such as acidic sodium sulfite, hydrogen peroxide, 4,4 '-Azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, and other water-soluble polymerization initiators, and these water-soluble polymerization initiators as a component combined with a reducing agent such as ferrous salt Redox initiator systems, benzoyl peroxide, 2,2′-azobis-isobutyronitrile, and the like are used. These polymerization initiators may be added to the polymerization system before, simultaneously with the addition of the monomer, or after the addition, and these addition methods may be combined as necessary.

Moreover, a well-known chain transfer agent can be used as needed, and specific examples include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen, carbon tetrachloride, trichlorobromomethane and the like. The chain transfer agent may be used alone or in combination of two or more, and is used in an amount of 0 to 5% by mass based on the polymerizable monomer.
Moreover, a well-known suspension stabilizer can be used as needed. Specific examples of the suspension stabilizer include calcium phosphate, magnesium phosphate calcium hydroxide, magnesium hydroxide and the like. These may be used alone 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 these addition methods are combined as necessary. May be.
In addition, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, and the like can be appropriately added to the reaction system.

  The blending of the colorant in the emulsion polymerization aggregation method is usually performed in an aggregation step. A dispersion of polymer primary particles and a dispersion of colorant particles are mixed to form a mixed dispersion, which is then aggregated to form a particle aggregate. 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 preferably 0.01 μm or more, more preferably 0.05 μm or more, preferably 3 μm or less. More preferably, it is 1 μm or less.

  When a charge control agent is contained in the toner using the emulsion polymerization aggregation method, the charge control agent is added together with the polymerizable monomer during emulsion polymerization, or added in the aggregation step together with the polymer primary particles and the colorant. Or it can mix | blend by methods, such as adding after polymer primary particle, a colorant, etc. are aggregated and it becomes the target particle diameter substantially. Among these, it is preferable to disperse the charge control agent in water using a surfactant and add it to the aggregation step as a dispersion having a volume average particle size of 0.01 μm or more and 3 μm or less.

The aggregation step in the emulsion polymerization aggregation method is performed in a tank equipped with a stirrer, and there are a method of heating, a method of adding an electrolyte, and a method of combining these. When polymer primary particles are aggregated with stirring to obtain particle aggregates of the desired size, the particle size of the particle aggregate is controlled from the balance between the cohesive force between the particles and the shearing force by stirring. However, the cohesive force can be increased by heating or adding an electrolyte.

When aggregation is performed by adding an electrolyte, both an organic salt and an inorganic salt can be used as the electrolyte. Specifically, as the electrolyte, NaCl, KCl, LiCl, Na ₂ S
O ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ , CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ , CH ₃ COONa, C ₆ H ₅ SO ₃ Na and the like. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred.

  The amount of electrolyte added varies depending on the type of electrolyte, target particle size, etc., but is preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more with respect to 100 parts by mass of the solid component of the mixed dispersion. preferable. Further, it is preferably 25 parts by mass or less, more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less. When the addition amount is in the above range, the agglomeration reaction can be rapidly advanced, and the particle size can be controlled relatively easily without causing fine powder or an irregular shape after the agglomeration reaction. Particle aggregates having an average particle size can be obtained. The aggregation temperature in the case of performing aggregation by adding an electrolyte is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, preferably 70 ° C. or lower, more preferably 60 ° C. or lower.

  The aggregation temperature in the case of performing aggregation only by heating without using an electrolyte is preferably (Tg-20) ° C. or higher, and more preferably (Tg-10) ° C. or higher, where Tg is the glass transition temperature of the polymer primary particles. . Moreover, Tg or less is preferable and (Tg-5) degrees C or less is still more preferable. The time required for agglomeration is optimized depending on the shape of the apparatus and the processing scale, but in order for the toner particle size to reach the target particle size, it is usually held at the predetermined temperature for at least 30 minutes. desirable. The temperature rise until reaching the predetermined temperature may be raised at a constant rate, or may be raised stepwise.

  If necessary, particles having adhered or fixed resin particles may be formed on the surface of the particle aggregate after the aggregation treatment. In some cases, the chargeability and heat resistance of the obtained toner can be improved by attaching or fixing the resin particles whose properties are controlled to the surface of the particle aggregate, and further, the effects of the present invention can be made more remarkable. . When resin particles having a glass transition temperature higher than that of the polymer primary particles are used as the resin particles, it is preferable because blocking resistance can be further improved without impairing fixing properties. The volume average particle size of the resin particles is preferably 0.02 μm or more, and more preferably 0.05 μm or more. Moreover, 3 micrometers or less, Furthermore, 1.5 micrometers or less are preferable. As the resin particles, those obtained by emulsion polymerization of monomers similar to the polymerizable monomers used for the above-mentioned polymer primary particles can be used.

  Resin particles are usually used as a dispersion dispersed in water or a liquid mainly composed of water using a surfactant. However, when a charge control agent is added after the aggregation treatment, charge control is performed on the dispersion containing particle aggregates. It is preferable to add the resin particles after adding the agent. In order to increase the stability of the particle aggregate obtained in the aggregation step, it is preferable to perform fusion in the aggregated particles in the aging step after the aggregation step.

  In the emulsion polymerization aggregation method, the temperature of the aging step after the aggregation step is preferably at least Tg of the polymer primary particles, more preferably at least 5 ° C higher than Tg, and preferably Tg. The temperature is 80 ° C. or higher, more preferably 50 ° C. or lower than Tg. The time required for the aging step varies depending on the shape of the target toner, but is preferably 0.1 to 10 hours, more preferably 1 to 6 hours after reaching the glass transition temperature of the polymer primary particles. To do.

  In addition, it is preferable to add a surfactant or raise the pH value after the aggregation process, preferably before the aging process or during the aging process. As the surfactant used here, one or more emulsifiers can be selected from the emulsifiers that can be used when producing the polymer primary particles. In particular, the emulsifiers used when producing the polymer primary particles. It is preferable to use the same. Although the addition amount in the case of adding surfactant is not limited, Preferably it is 0.1 mass part or more with respect to 100 mass parts of solid components of a mixed dispersion liquid, More preferably, it is 1 mass part or more, More preferably, it is 3 masses. It is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 10 parts by mass or less. After the aggregation process, before the completion of the ripening process, by adding a surfactant or raising the pH value, it is possible to suppress aggregation of the particle aggregates aggregated in the aggregation process, In some cases, the generation of coarse particles can be suppressed.

  By heat treatment in the aging step, the polymer primary particles in the aggregate are fused and integrated, and the toner particle shape as the aggregate becomes close to a spherical shape. The particle aggregate before the aging step is considered to be an aggregate due to electrostatic or physical aggregation of the polymer primary particles, but after the aging step, the polymer primary particles constituting the particle aggregate are fused to each other. In addition, the shape of the toner base particles can be made nearly spherical. According to such a ripening step, by controlling the temperature and time of the ripening step, toner mothers having various shapes such as a shape in which the polymer primary particles are aggregated, a spherical shape in which the fusion has progressed, and the like have been performed. Particles can be obtained.

[Toner mother particle cleaning process]
The toner base particles obtained by a wet method such as a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method are obtained by solid-liquid separation of the toner base particles obtained from the wet medium, and the toner base particles are aggregated into particle aggregates. It is preferable to carry out washing as necessary after the recovery.
As the liquid used for cleaning, water having a higher purity than the wet medium in which the toner is immersed in the final step of the wet method may be used, or an aqueous solution of acid or alkali may be used. As the acid, inorganic acids such as nitric acid, hydrochloric acid and sulfuric acid, and organic acids such as citric acid can be used. As the alkali, soda salts (sodium hydroxide, sodium carbonate, etc.), silicates (sodium metasilicate, etc.), phosphates, etc. can be used. Cleaning can also be performed by heating to room temperature or about 30 to 70 ° C.

  From the toner mother particles, the suspension stabilizer, the emulsifier, the wet medium, the unreacted residual monomer, the toner having a small particle diameter, and the like are removed by the washing step. After the washing step, the toner base particles are preferably obtained in a wet cake state by filtration or decantation. This is because the handling becomes easy in the subsequent process. The washing process may be repeated a plurality of times.

[Moisture removal process of toner base particles]
The method for producing an electrostatic charge developing toner according to the present invention preferably includes a step of removing the water content of the toner base particles to 0.4% by mass or less before the drying step described later. Since the wet cake-like toner base particles after the washing step are in a wet state, the water content in the toner base particles is 50% by weight or less, more preferably 40% by weight or less, with respect to 100% by weight of the toner base particles. More preferably, it is 30 mass% or less. The wet mother toner particles are evaporated in advance until the water content becomes 0.4% by mass or less, whereby a volatile organic compound contained in the toner mother particles in the subsequent drying step. Can be efficiently diffused.

As the dryer used in the moisture removal step, a fluid dryer, a jet dryer, a vacuum dryer, or the like can be used. The latent heat of moisture evaporation is directly applied to the toner base particles to increase the moisture removal rate. For this reason, it is preferable to use a fluidized drier in which gas is introduced and dried. For example, a fluidized dryer with a vibration device described later can be used, and a fluidized dryer without a vibration device can also be used. It is more preferable to use a fluidized dryer without a vibration device. The gas applied to the fluidized dryer used in the moisture removal process, the temperature of the gas, the temperature of the dryer, etc. are the gas applied to the fluidized dryer with vibrator used in the drying process described later, the temperature of the gas, the temperature of the dryer Etc., and similar gases and conditions can be applied.

[Drying process of toner base particles]
In the step of drying the toner base particles, a dryer such as a fluid dryer, a jet dryer, or a vacuum dryer can be used. Of these, drying with a fluidized dryer equipped with a vibration device is preferred. The fluidized dryer with a vibration device can quickly dry the toner base particles by using the latent heat of vaporization of the water contained in the toner base particles by flowing a gas into the main body of the dryer. In addition, by applying vibration to the toner base particles with a vibration device, the toner base particles can be fluidized even if the gas flow rate is reduced, and the aggregates gathered in the lower part are crushed and quickly and efficiently. Thus, the toner base particles can be dried.

Drying is preferably performed under normal pressure or reduced pressure. Under reduced pressure, the amount of heat that can be given to the toner base particles by the gas becomes small. Therefore, drying at normal pressure is more preferable.
[Toner forming process]
Next, an external additive is added to the toner base particles, and the external additive is adhered or fixed to the surface of the toner base particles to form a toner. By adding external additives, OPC (organic
photoconductors) filming and transfer efficiency can be improved.

As a method for adding the external additive to the toner base particles, a method in which the external additive is added to the system charged with the toner base particles and mixed by stirring is used. For the stirring and mixing of the toner base particles and the external additive, it is preferable to use a mechanical rotary processing device, and specifically, a rotary mixer such as a Henschel mixer is preferably used.
The speed (peripheral speed) of the tip of the stirring blade in the addition treatment using such an apparatus is 21.2 to 95.5 m / sec, preferably 38.2 to 76.4 m / sec. It is preferable. By adjusting the rotation speed, it is possible to adjust the embedding of the external additive in the colored particles by this stirring and mixing treatment, and as a result, the fluidity of the obtained toner can be controlled.

In the toner of the present invention, it is preferable that the external additive is uniformly attached to the surface of the toner particles, but a plurality of particles having different particle diameters (hereinafter also referred to as “multiple diameter particles”). ) As an external additive, the external additives can be uniformly adhered to the surface of the toner particles by mixing each external additive by mixing two or more stages. It is preferable to use a multistage mixing method in which a small particle size external additive is added and mixed, and then a large particle size external additive is added and mixed.
The stirring time for the stirring and mixing process can be determined according to the stirring speed and the like.
As temperature which adds an external additive, 25 to 55 degreeC is preferable and 30 to 50 degreeC is more preferable.

[Physical properties of toner]
The average circularity of the toner produced by the method of the present invention is preferably 0.955 or more, and more preferably 0.960 or more. Moreover, it is preferable that it is 0.985 or less, and it is more preferable that it is 0.980 or less. When the average circularity of the toner is within the above range, a good image can be formed.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following example, “part” means “part by mass”.
Means. In addition, the live-action test was conducted by the following method.
Measurement methods and definitions of physical properties, shapes, etc. used in the description of the present invention are shown below.

<Measurement method of volume average diameter (Mv)>
The volume average diameter (Mv) of the particles having a volume average diameter (Mv) of less than 1 μm is determined by the handling of nanotracks using Nikkiso Co., Ltd., model: Microtrac Nanotrac 150 (hereinafter abbreviated as “nanotrack”). According to the instructions, the company's analysis software Microtrac Particle Analyzer Ver10.1.2. -019EE, solvent refractive index: 1.333, measurement time: 100 seconds, number of measurements: once, wax dispersion and polymer primary particle dispersion, particle refractive index: 1.59, permeability: The colorant dispersion was measured under the conditions of permeability: absorption, shape: non-spherical, density: 1.0 under conditions of transmission, shape: true sphere, density: 1.04.

<Measurement method of volume median diameter (Dv50)>
The volume median diameter (Dv50) of the particles having a volume median diameter (Dv50) of 1 μm or more is dispersed using Beckman Coulter Multisizer III (aperture diameter 100 μm) (hereinafter abbreviated as “multisizer”). Isoton II manufactured by the same company was used as the medium, and the dispersion was measured so that the dispersoid concentration was 0.03% by mass. The measurement particle diameter range is from 2.00 to 64.00 μm, and this range is discretized into 256 divisions so as to be equidistant on a logarithmic scale, and the volume calculated based on the statistical values on the basis of the volume is the volume. The median diameter (Dv50) was used.

<Measuring method of average circularity>
The “average circularity” in the present invention is measured and defined as follows. That is, the toner base particles are dispersed in a dispersion medium (Isoton II, manufactured by Beckman Coulter, Inc.) so as to be in the range of 5720-7140 particles / μL, and a flow type particle image analyzer (Sysmex Corporation (formerly Toa Medical Electronics)). (Manufactured by FPIA 2100), measurement is performed under the following apparatus conditions, and the value is defined as “average circularity”. In the present invention, the same measurement is performed three times, and an arithmetic average value of three “average circularity” is adopted as the “average circularity”.
・ Mode: HPF
-HPF analysis amount: 0.35 μL
-Number of detected HPFs: 2000 to 2500 The following are measured by the above apparatus and automatically calculated and displayed in the above apparatus, but "circularity" is defined by the following equation.

[Circularity] = [Perimeter of a circle with the same area as the projected particle area] / [Perimeter of projected particle image]
And 2000-2500 which is the number of HPF detection is measured, and the arithmetic average (arithmetic mean) of the circularity of each individual particle is displayed on the apparatus as “average circularity”.
<Measurement method of BET specific surface area>
The measurement was performed by a one-point method using liquid nitrogen using a Macsorb model-1201 manufactured by Mountec Co., Ltd. Specifically, it is as follows.

First, about 1.0 g of a measurement sample was filled in a dedicated cell made of glass (hereinafter, this sample filling amount is referred to as A (g)). Next, the cell was set on the measuring device main body, dried and degassed at 200 ° C. for 20 minutes in a nitrogen atmosphere, and then the cell was cooled to room temperature. Thereafter, while the cell is cooled with liquid nitrogen, a measurement gas (mixed gas of 30% primary nitrogen and 70% helium) is flowed into the cell at a flow rate of 25 mL / min, and the amount of measurement gas adsorbed V (cm ³ ) was measured. When the total surface area of the sample is S (m ² ), the desired BET specific surface area (m ² / g) can be calculated by the following calculation formula.

(BET specific surface area) = S / A
= [K · (1-P / P ₀ ) · V] / A
K: Gas constant (4.29 in this measurement)
P / P ₀ : relative pressure of the adsorbed gas, 97% of the mixing ratio (0.29 in this measurement)
<Measuring method of average particle diameter of external additive>
The average particle size of the external additive refers to the number average particle size. The particle size (average value of the major axis and the minor axis) of 500 particles is measured from a scanning electron microscope (SEM) photograph, and the average value is averaged. The particle size.

<ID (image density)>
Average ID 1.25 <w ○: Sufficient density Average ID 1.15 ≦ w ≦ 1.25 △: There is no problem in practical use, but depending on the print image, the density may be insufficient. Average ID w <1.15 ×: Insufficient density Yes <BG (paper coupling>)
BG MAX x <0.8 ○: No problem at all
BG MAX 0.8 ≦ x ≦ 1.0 △: No problem in practical use, but if you stare, you may feel coloring in the non-printed area
BG MAX 1.0 ≦ x ×: Coloring of non-printing area becomes a problem

<TC (toner consumption [g / kp])>
TC y <20 ○: No problem with the number of prints
TC 20 ≦ y ≦ 22 Δ: No problem in practical use, but the number of printable sheets may decrease depending on the printing environment.
TC 22 <y ×: The number of printable sheets is small and is a problem <Recovered amount [g]>
Collected amount z <8 ○: There is a margin in the collection box and no problem occurs. Collected amount 8 ≦ z ≦ 10 △: There is no problem in practical use, but the collected toner may overflow depending on the printing environment. Collected amount 10 < z x: Recovery overflow becomes a problem

<< Regarding Toner Base Particle C1 >>
<Adjustment of colorant dispersion>
Carmine magenta pigment (Pigment Red) in a container of a stirrer equipped with a propeller blade
269) 20 parts, nonionic surfactant (manufactured by Kao Corporation, Emulgen 120 (HLB value 15.3, polyoxyethylene lauryl ether with cloud point 98 ° C.)) 4.0 parts (20 parts relative to pigment), conductive 100 parts of ion-exchanged water having a rate of 2 μS / cm was added and predispersed to obtain a pigment premix solution.

The premix solution was used as a raw material slurry and supplied to a wet bead mill equipped with a rotating screen (mesh separator for bead separation) for circulation dispersion. Note that zirconia beads (true density of 6.0 g / cm ³ ) having a diameter of 120 mmφ, a separator having a diameter of 60 mmφ, and a diameter of 100 μm (0.1 mm) were used as a dispersion medium. The effective internal volume of the stator is about 0.5 L, and the media filling volume is 0.35 L, so the media filling rate is 70%.
The premix slurry was supplied from the supply port at a supply speed of about 54 L / hr by a non-pulsating metering pump with the rotor rotating speed kept constant (the peripheral speed at the rotor tip was about 7 m / sec). During operation, cooling water of about 10 ° C. was circulated from the jacket to obtain a magenta “colorant dispersion” having a volume median diameter Dv1 of 0.12 μm and a viscosity of 70 cP.

<Preparation of wax dispersion A1>
As wax 1, HNP9 (Nippon Seiwa Co., Ltd .: melting point 74 ° C) 27.3 parts, stearyl acrylate 2.7
Part, 20% sodium dodecylbenzenesulfonate aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20D, hereinafter abbreviated as 20% DBS aqueous solution) 2.8 parts, demineralized water 67.3 parts added, and 100 ° C.
Was used, and primary circulation emulsification was performed under a pressure condition of 10 MPa using a homogenizer with a pressure circulation line (manufactured by Gorin, LAB60-10TBS type). The particle diameter is measured every few minutes with LA950, and when the median diameter is reduced to around 500 nm, the pressure condition is further increased to 25 MPa, followed by secondary circulation emulsification. A wax dispersion A1 was produced by dispersing until the median diameter was 230 nm or less. The final median diameter was 227 nm.

<Preparation of Polymer Primary Particle Dispersion B1> The above wax dispersion A1 36. was prepared in a reactor equipped with a stirrer for core (three blades), a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device. 0 parts and 255 parts of demineralized water were charged, and the temperature was raised to 90 ° C. under a nitrogen stream while stirring.
Thereafter, the mixture of the following “polymerizable monomers and the like” and “emulsifier aqueous solution” was added to the solution over 5 hours while continuing to stir the liquid. The time at which this mixture was started to be dropped was designated as “polymerization start”, and the following “initiator aqueous solution” was added over 4.5 hours from 30 minutes after the start of polymerization. Further, after 5 hours from the start of polymerization, the following “additional start” The agent aqueous solution ”was added over 2 hours, and the internal temperature was maintained at 90 ° C. for 1 hour while continuing stirring.

[Polymerizable monomers, etc.]
Styrene 76.8 parts Butyl acrylate 23.2 parts Acrylic acid 0.85 parts Hexanediol diacrylate 0.7 parts Trichlorobromomethane 0.64 parts
[Emulsifier aqueous solution]
20% DBS aqueous solution 0.8 parts Demineralized water 67.1 parts
[Initiator aqueous solution]
8% by mass aqueous hydrogen peroxide solution 15.5 parts 8% by mass L (+)-ascorbic acid aqueous solution 15.5 parts
[Additional initiator aqueous solution]
8 mass% L (+)-ascorbic acid aqueous solution 14.2 parts It cooled after completion | finish of polymerization reaction, and milky-white polymer primary particle dispersion liquid B1 was obtained. The volume average diameter (Mv) measured using Nanotrac was 251 nm, and the solid content concentration was 22.6% by mass.

<Preparation of Polymer Primary Particle Dispersion B2> 20% DBS aqueous solution in a reactor equipped with a stirring device (three blades) for shell, a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device 2.0 Part and 355 parts of demineralized water were added and the temperature was raised to 90 ° C. under a nitrogen stream while stirring. When the temperature reached 90 ° C., the following “initiator aqueous solution for first charge” was added.

Thereafter, the mixture of the following “polymerizable monomers and the like” and “emulsifier aqueous solution” was added to the solution over 5 hours while continuing to stir the liquid. The time at which this mixture was started to drop was defined as “polymerization start”, and the following “initiator aqueous solution” was added over 6.0 hours from 0 minutes after the start of polymerization, and the internal temperature was kept at 90 ° C. while continuing stirring. Held for hours.
[Polymerizable monomers, etc.]
Styrene 100.0 parts Acrylic acid 0.5 parts Trichlorobromomethane 0.5 parts
[Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part Demineralized water 42.1 parts
[First-injection initiator aqueous solution]
8% by mass aqueous hydrogen peroxide solution 3.2 parts 8% by mass L (+)-ascorbic acid aqueous solution 3.2 parts
[Initiator aqueous solution]
8% by mass aqueous hydrogen peroxide solution 18.9 parts 8% by mass L (+)-ascorbic acid aqueous solution 18.9 parts After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion B2. The volume average diameter (Mv) measured using Nanotrac was 156 nm, and the solid content concentration was 19.6% by mass.

<Manufacture of toner mother particle C1>
Using the following components, toner base particles C1 were produced by carrying out the following aggregation process (core material aggregation process / shell coating process) / circularization process.
Polymer primary particle dispersion B1 90 parts as solid content (dispersion B1: 314.5 kg / solid content: 62.9 kg for core)
Polymer primary particle dispersion B2 10 parts as solid content (dispersion B2: 35.5 kg / solid content: 7.1 kg for shell)
Colorant fine particle dispersion 5.0 parts as a colorant solid content 20% DBS aqueous solution 4 parts as a solid content in the rounding step

○ Core material agglomeration step Polymer primary particle dispersion B1 was charged into a mixer (volume 1000 L, inner diameter 850 mm) equipped with a stirrer (double helical blade), heating / cooling device, and raw material / auxiliary charging device, and 20% DBS. 0.1 part of an aqueous solution was added and mixed uniformly at an internal temperature of 10 ° C. for 10 minutes. Then at an internal temperature of 10 ° C., allowed to stir at 101Rpm, a 5 wt% aqueous solution of potassium sulfate _from continuously added over 1 minute 0.12 parts as K 2 SO _4, the colorant particle dispersion liquid 5 The mixture was continuously added over a minute and mixed uniformly at an internal temperature of 10 ° C.
Then, after adding 0.2 part by weight of 0.5 mass% aqueous solution of aluminum sulfate continuously over 30 minutes, the internal temperature was raised to 55.0 ° C. over 90 minutes while maintaining the rotation speed at 101 rpm. Then, after 30 minutes, the temperature was raised to 1.0 ° C., held at 56.0 ° C., the volume median diameter was measured using a multisizer, and grown to 7.60 μm.

○ Shell coating step Thereafter, the polymer primary particle dispersion B2 was continuously added over 15 minutes while maintaining the internal temperature of 56.0 ° C. and the rotation speed of 101 rpm, and held as it was for 60 minutes. At this time, the Dv50 of the particles was 7.63 μm.
○ Circularization Step Subsequently, the stirring rotation was changed to 70 rpm, and the temperature was raised to 90 ° C. while adding a mixed aqueous solution of 20% DBS aqueous solution (4 parts as solids) and 0.04 part of water over 30 minutes. Thereafter, the temperature was raised to 98.5 ° C., and heating and stirring were continued under these conditions until the average circularity reached 0.968 over 1.5 hours. Thereafter, the mixture was cooled to 30 ° C. over 35 minutes to obtain a slurry of toner base particles C1. At this time, the volume median diameter of the particles is 7.58 μm, the number median diameter is 6.91 μm, the distribution (volume median diameter) / (number median diameter) is 1.097, and the average circularity is 0.971. there were.

○ Washing and drying process Using a wet electromagnetic sieve shaker (AS200 / Lecche Co., Ltd.) equipped with a sieve with a mesh size of 24μm, the resulting slurry is filtered for the purpose of removing coarse particles and equipped with a stirrer Once stored in the tank. Thereafter, this slurry was subjected to a horizontal centrifuge (HZ40Si type / Mitsubishi Chemical Corporation) equipped with a filter cloth (polyester TR815C, Nakao filter industry / thickness 0.3 mm / air permeability 48 (cc / cm ² / min)). Then, centrifugal dehydration washing was performed under the condition of acceleration 800G. When ion-exchanged water having an electric conductivity of 1 μS / cm was added at a rate not to overflow from the rim at about 50 times the amount of slurry solids, the electric conductivity of the filtrate was 2 μS / cm. Finally, water was thoroughly shaken off, and the cake was recovered with a scraping device.
The obtained cake was spread on a stainless steel bat so as to have a height of 20 mm, and dried in a blow dryer set at 40 ° C. for 48 hours to obtain toner mother particles C1.

<External additive>
The following external additives were used in the examples.
Silica particles: polydimethylsiloxane-treated silica particles, average primary particle size 11 nm, BET specific surface area 120 m ² / g
Inorganic particles 1: Titanium oxide particles, average primary particle size 15 nm, BET specific surface area 78 m ² / g
Inorganic particles 2: Titanium oxide particles, average primary particle size 0.25 μm, BET specific surface area 15 m ² / g Inorganic particles 3: Hydrotalcite particles, average primary particle size 0.4 μm, BET specific surface area 9 m ² / g

Toner shell particles C1 are charged into a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and then 0.2 parts of silica particles are charged with respect to 100 parts by mass of the toner mother particles and mixed until 35 ° C. is reached. Thereafter, 1.6 parts of silica particles are added to 100 parts by weight of toner base particles and 0.4 parts of inorganic particles 1 are added to 100 parts by weight of toner base particles, and mixed for 10 minutes. Further, 0.02 part of inorganic particles 2 is added to 100 parts by weight of toner base particles and 0.05 part of inorganic particles 3 is added to 100 parts by weight of toner base particles, and mixed for 6 minutes.
The same mixing as described above was performed on nine toner base particles a to i having different base particle creation dates, and toners A to I were obtained.

<Example 1>
Table 1 shows the results of analyzing the obtained toner base particles a by XPS.
In addition, the toner A is subjected to a heat load of 45 ° C., 85%, 60 hours, and then has a non-magnetic single component, an organic photoreceptor charged by a charging roller, and has a developing roller having a diameter of 12 mm. A printing test of 2500 sheets was performed in an environment of a temperature of 23 ° C. and a humidity of 50% using a full-color printer with a developing roller peripheral speed ratio of 1.5 and a printing speed of 47 mm / sec. Table 2 shows the measurement results of average ID, BG (paper fog) MAX, TC (toner consumption), and toner recovery amount.
A good image was obtained without any particular problem.

<Examples 2 to 4>
Table 1 shows the results of analyzing the obtained toner base particles b to d by XPS and the results of NMR analysis of c and d.
Further, a printing test was performed on toner B, toner C, and toner D in the same manner as in Example 1. The results are shown in Table-2.
Again, for all toners, good images were obtained with no particular problems.

<Example 5>
The results of analyzing the obtained toner base particles e by XPS are shown in Table 1.
For Toner E, a print test was performed in the same manner as in Example 1. The results are shown in Table-2.
In paper fog, a sufficient performance margin could not be obtained, but it was at a level where there was no practical problem. There were no other problems.
<Comparative Examples 1-4>
Table 1 shows the results of analyzing the obtained toner base particles f to i by XPS and the results of NMR analysis of f to h.
A printing test was performed on toner F, toner G, toner H, and toner I in the same manner as in Example 1. The results are shown in Table-2.
For all four toners, there were problems that caused problems with one or more of the items of average ID, BG (paper fog) MAX, TC (toner consumption), and toner recovery amount.

Claims (3)

A toner for developing an electrostatic charge image containing at least a colorant and a binder resin, wherein the ratio of sulfur atom to carbon atom by SPS by surface element composition analysis by XPS is N / C and the ratio of nitrogen atom is N / C A toner for developing electrostatic images, wherein the product of S / C and N / C satisfies the following formula (1):
S / C · N / C ≦ 6.6 × 10 ⁻⁶ (1) 2. The electrostatic image developing toner according to claim 1, wherein the S / C value is 0.7 × 10 ⁻³ or less. The electrostatic charge image developing toner according to claim 1 or 2, wherein the amount of the residual surfactant on the toner surface detected by ¹ H-NMR is 280 ppm or less.