JPH10319630A - Production of toner for developing electrostatic charge image and toner for developing electrostatic charge image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably obtain appropriate and uniform electrification amount, to prevent fogging and the lowering of image density and to stably obtain a distinct image by mixing coloring particles and additive while humidifying them by spraying the droplets of water so that the water content of toner for developing an electrostatic charge image just after mixing may be within a specified range. SOLUTION: The coloring particles and the additive are measured by specified amount and thrown in a mixer 11 from the throw-in port P1 of the upper cover of the mixer 11. Next, a motor 13 is driven to rotate a stirring blade 12. While stirring, water and compressed air are supplied to a spray nozzle 7 and the droplets are sprayed, whereby the toner is produced. When the toner having the desired water content is obtained, the stirring blade 12 is stopped and the humidification by the nozzle 7 is stopped. In the case of producing the toner, the coloring resin and the additive are mixed while they are humidified by means of spraying the droplets of the water so that the water content of the toner just after mixing may be 0.10-2.0 wt.%. Thus, they are uniformly mixed and dispersed without receiving electrostatic trouble caused by mutual friction between the particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner for developing an electrostatic image used in electrophotography, electrostatic recording, electrostatic printing, and the like, and a toner for developing an electrostatic image obtained by the method.

[0002]

2. Description of the Related Art Generally, in order to form an image by electrophotography, an electrostatic image is formed on an electrophotographic photosensitive member (hereinafter, also simply referred to as a photosensitive member) through charging and image exposure, and the electrostatic image is formed. A toner image is formed by developing with a developing toner (hereinafter, also simply referred to as toner), and the toner image is fixed on a support by heating or pressing to form a visible image.

Conventionally, in order to manufacture the above toner, first, a colorant, a release agent, a charge control agent, and, if necessary, other auxiliaries are blended into a binder resin, and the obtained blend is premixed. ,
It is produced by melting and kneading, cooling and pulverizing, and classifying to obtain colored particles, and further mixing inorganic fine particles and, if necessary, organic fine particles and external additives such as a lubricant with the colored particles. In addition,
The purpose of adding the external additive is to improve the fluidity of the toner and to control the chargeability.

On the surface of the colored particles, since a binder resin, a coloring agent, a release agent, a charge controlling agent, and the like are present in various different composition distributions, portions having different charging properties are exposed. Exist. When an external additive is mixed with such colored particles, due to mutual friction between the colored particles and the external additive, the external additive is selectively attached to a portion which is easily electrostatically attached to the colored particles, As a result, the chargeability of the obtained toner becomes nonuniform, resulting in a problem that an excessively charged toner or a weakly charged toner is generated, and a toner stably having an appropriate charged amount cannot be obtained.

[0005] In particular, the colored particles immediately after the kneading, pulverizing and classifying steps are extremely dry and in an electrostatically active state. Microscopic ubiquity of the external additive occurs due to friction, causing excessively charged toner or weakly charged toner.
As described above, a toner having an appropriate and uniform charge amount cannot be stably obtained, which causes fog and a decrease in image density when an image is formed by electrophotography or the like.

As a prior art, as for the humidification of toner raw materials such as colored particles and external additives, see, for example, JP-A-3-116.
No. 053 and Japanese Patent Application Laid-Open No. 7-56389 are known.

[0007]

However, the above-mentioned Japanese Patent Application Laid-Open No. Hei 3-116053 merely defines the water content of an external additive (fluidity imparting agent) under a specific environment. Japanese Patent No. 56389 describes a method of adjusting the humidity by introducing humidified air when mixing raw materials such as colored particles and external additives. In this method, fine powders such as the colored particles and the external additives are described. There is a disadvantage that it is difficult to control the amount of humidity control for the water, and that proper humidity control cannot be performed. In addition, many studies on humidity control of raw materials of toner have been made, but none of them is satisfactory, and at present, a toner having an appropriate and uniform charge amount has not been obtained.

The present invention has been proposed in view of the above-mentioned circumstances, and an object thereof is to stably obtain an appropriate and uniform charge amount, and to reduce fog and fog when an image is formed by electrophotography. An object of the present invention is to provide a method for producing a toner capable of stably obtaining a clear image without a decrease in image density, and a toner obtained by the method.

[0009]

The above object is achieved by the following constitution.

[0010] 1. In the method for producing a toner for developing an electrostatic image, the method for producing a toner for developing an electrostatic image having a process of mixing at least a coloring particle containing a colorant and a binder resin and an external additive, the water content of the toner for developing an electrostatic image immediately after mixing is 0.10 to 0.10. A method for producing a toner for developing an electrostatic charge image, characterized by mixing while humidifying by spraying water droplets so as to be 2.0 wt%.

2. A method for producing a toner for developing an electrostatic charge image as described in the above item 1, wherein water is mixed while humidifying by spraying water droplets having a volume median diameter of 100 μm or less with a 2.2 fluid spray nozzle. Method.

3. 3. An electrostatic image developing toner manufactured by the manufacturing method according to the above 1 or 2.

Hereinafter, the configuration of the present invention will be described in detail.

According to the present invention, when a toner for developing an electrostatic charge image is produced by mixing colored particles containing at least a colorant and a binder resin and an external additive, the toner immediately after mixing has a water content of 0.1%.
By mixing the colored particles and an external additive to produce a toner while spraying and humidifying water droplets so as to have a concentration of 10 to 2.0 wt%, electrostatic interference due to mutual friction between the particles is produced. This makes it possible to uniformly mix and disperse the colored particles and the external additive without receiving the toner, and as a result, it is possible to stably produce a toner having an appropriate and uniform charge amount. Yes.

As described above, the reason why the toner having excellent chargeability can be obtained by mixing the colored particles and the external additive by spraying liquid droplets of water while humidifying to produce a toner is as follows. Although it is not always clear, it is presumed as follows. Specifically, the positively charged toner will be described as an example. Generally, the colored particles of the positively charged toner generally include a binder resin, a colorant, and a release agent (for example, a material having a relatively negative chargeability such as low molecular weight polypropylene or polyethylene). ), A charge control agent (for example, a material having a high positive charge property such as a nigrosine dye or a quaternary ammonium salt compound) and the like.
Now, when adding and mixing a relatively positively charged external additive that is also in a dry state to the colored particles in a dry state,
The external additive selectively adheres to a highly negatively charged portion of the colored particles (for example, a portion of the release agent exposed on the surface),
A toner having an excessively high charge amount (positive) can be obtained. Therefore, when this is used for image formation as, for example, a two-component developer, the development becomes insufficient compared with the case where a toner to which an external additive is uniformly adhered is used, and a sufficiently satisfactory image density cannot be obtained. Occurs.

In the case where an external additive having a relatively low negative charge property is also used in the dry state with respect to the colored particles in the dry state, the external additive may be used as the positive charge property of the colored particles. It selectively adheres to a high portion (for example, a charge control agent portion exposed on the surface), and a toner having a low charge amount can be obtained. Therefore, when this is used for image formation as, for example, a two-component developer, there is a problem that over-development is likely to occur and fogging tends to occur as compared with the case where a toner to which an external additive is uniformly attached is used. .

The present inventors have found that the electrostatic interaction between the colored particles and the external additive is achieved by mixing the colored particles and the external additive while spraying liquid droplets of water and humidifying the mixture. Relaxed,
The uniform dispersion of the external additive with respect to the colored particles was realized, and it was possible to stably obtain a toner having an appropriate and uniform charge amount.

Here, when the toner of the present invention is manufactured by mixing the colored particles and the external additive, if the water content of the toner immediately after mixing is less than 0.10 wt%, the humidifying effect is not exhibited.
The chargeability of the toner becomes excessively high, and when used as a developer, the development becomes insufficient and the image density decreases. 2.0w
When the amount exceeds t%, aggregation of the external additive and the toner starts, and a desired charge amount cannot be obtained when the toner is used as a developer.
Fog occurs due to excessive development.

Next, as a method of spraying and humidifying water droplets of the present invention, there is a method using an ultrasonic humidifier or a spray nozzle. A method using a spray nozzle is preferred because humidification is achieved and industrial processing is easy, and a two-fluid spray nozzle is suitably used particularly from the viewpoint that finer water droplets can be easily obtained.

<Structure of Spray Nozzle and Humidifying Method> In producing a toner by mixing the colored particles of the present invention and an external additive, a two-fluid spray nozzle which sprays and humidifies water droplets during mixing is described. A fine spray is created by jetting and mixing a gas and a liquid from respective nozzles. There are basically the following three methods for mixing the above gas and liquid.

That is, an internal mixing method: a method in which a gas and a liquid are mixed in advance in a mixing chamber inside a nozzle and sprayed as a spray, and an external mixing method: a liquid is sprayed as a liquid column from an orifice of a liquid cap. Immediately after that, a liquid column is pulverized by a gas injected from an orifice of a gas cap and sprayed as a spray by spraying, and a siphon type: a liquid is sucked up by a suction force generated by a supplied gas, and the liquid is sucked from a nozzle. At the same time, there is a method of mixing with gas and spraying as a spray.

Although any of the above methods may be used, in the method for producing a toner of the present invention, the volume median diameter of the water droplet is preferably 100 μm or less, and if the droplet diameter exceeds 100 μm. Aggregation of the colored particles and the external additive occurs, and the desired chargeability cannot be obtained, and the thickness is more preferably 50 μm or less.

As a means for obtaining the water droplets of 100 μm or less, a siphon type is preferably used. Further, the volume median diameter (hereinafter, also simply referred to as a droplet diameter) indicates that 50% of the sprayed liquid amount is equal to or smaller than the particle diameter, and the other 50% is equal to or larger than the particle diameter. The droplet diameter can be measured by a laser diffraction method.

<Configuration of humidifier using spray nozzle>
FIG. 1 shows an example of the configuration of a humidifier using a spray nozzle. In FIG. 1, first, a compressor 1 is operated and a high-speed stirring type mixer (hereinafter, also simply referred to as a mixer) 11 through a pressure reducing valve 2, a water tank 3, a needle valve 4, a flow meter 5, and a pressure gauge 6. A constant amount of water is supplied to the side A of the spray nozzle 7 installed on the upper lid 14. On the other hand, the compressed air is supplied to the B side of the spray nozzle 7 through the pressure reducing valve 8 and the pressure gauge 9 by the operation of the compressor 1 and mixed and injected with the water supplied in a fixed amount to humidify in the mixer 11. Humidify. At the same time, it is preferable to flow warm water through the jacket 10 and heat it. The droplet diameter can be adjusted by the type of cap of the spray nozzle 7, the mixing ratio of water and air, the pressure, and the like. Further, the spray flow rate can be controlled by the type of the cap of the spray nozzle 7, the pressure of water and air, etc. Further, by adjusting the spray time, the humidified material is set to have a desired moisture amount. be able to. Note that the droplet diameter is 1 instead of the 2-fluid spray nozzle.
Adjustments can also be made by using different types of spray nozzles, such as fluid spray nozzles.

As a specific humidification treatment method, a predetermined amount of colored particles and an external additive are measured and charged into the mixer 11 through the inlet P1 of the upper lid 14 of the mixer 11. Next, the motor 13
Is driven to rotate the stirring blade 12 to supply water and compressed air to the spray nozzle 7 while stirring, thereby spraying droplets to produce toner. When the desired amount of toner is obtained,
The stirring blade 12 is stopped, and the humidification by the spray nozzle 7 is stopped. Reference numeral 15 denotes a filter, and P2 denotes an outlet for taking out the obtained toner from the mixer 11.

<Measurement of Water Content> The water content of the toner obtained by the mixer 11 shown in FIG. 1 is measured by the Karl Fischer method “AQS-724” (manufactured by Hiranuma Sangyo Co., Ltd.), and particularly for sampling. Should be done as follows. The toner obtained by mixing the colored particles and the external additive under humidification is placed in a humidified atmosphere (in the mixer 11 or the container when the toner is transferred from the mixer 11 to a container having the same humidity). Inside), it is necessary to sample into a bottle with a dedicated packing and screw, and close the lid in an atmosphere of humidification. Otherwise, accurate values cannot be obtained for highly hydrophobic toner particles depending on the atmosphere in which they were sampled (the amount of water in the atmosphere becomes relatively short). As for the water content in the present invention, weak physical adsorption is also important, and the measurement requires careful attention.

[Construction of Toner] The toner of the present invention comprises colored particles and an external additive added to and mixed with the colored particles.

<Colored Particles> Examples of the binder resin contained in the colored particles constituting the toner of the present invention include polyester resins, styrene-alkyl acrylate resins, styrene-alkyl methacrylate resins, and styrene-butadiene. Resin, styrene-acrylonitrile resin, styrene-acryl-polyester resin, styrene-acryl-crystalline polyester graft resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl chloride,
Examples thereof include polyamide, polyvinyl butyral, rosin, modified rosin, phenol resin, xylene resin, and the like.

Examples of the coloring agent contained in the coloring particles include carbon black, chrome yellow, Dupont oil red, quinoline yellow, phthalocyanine blue, and magnetic substances. Ferrite, magnetite and other iron, cobalt,
A metal or alloy exhibiting ferromagnetism, such as nickel, or a compound containing these elements may be used.

As the release agent contained in the colored particles, for example, a low molecular weight polyethylene having a number average molecular weight of 1500 to 20,000 and a number average molecular weight of 1000 to 1
Polyolefin waxes such as 0000 low molecular weight polypropylene, low molecular weight polyethylene-polypropylene copolymers, for example, high melting point paraffin waxes such as microwax, Fischer-Tropsch wax, for example, fatty acid lower alcohol esters, fatty acid higher alcohol esters, fatty acid polyhydric alcohol esters, etc. Ester wax, amide wax and the like can be used.

Examples of the charge control agent contained in the colored particles include a negative charge control agent such as an azo metal complex, a salicylic acid metal complex, and a calixarene compound, a nigrosine dye, and a quaternary ammonium salt compound. And a positively chargeable charge control agent.

<External Additives> The external additives to be added to and mixed with the toner of the present invention may be either inorganic fine particles or organic fine particles, and if necessary, other additives such as a lubricant may be used. As inorganic fine particles, silica, titania, alumina, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide,
Cerium oxide, antimony trioxide, zirconium oxide,
Examples thereof include silicon carbide and silicon nitride. These may be either those subjected to hydrophobic treatment or those not subjected to hydrophobic treatment. The average particle size is a primary average particle size, from 0.005 μm to 3.
0 μm is preferable, especially 0.006 μm to 0.5 μm
m is preferred. The average particle diameter of the inorganic fine particles refers to a first-order average particle diameter measured by image analysis while observing with a scanning electron microscope.

In order to obtain inorganic fine particles in a preferable range, the amount of charge can be adjusted by performing a surface treatment using a surface treating agent. Examples of such a surface treating agent include titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, and bis (dioctyl pyrophosphate) oxyacetate titanate. Further, as the silane coupling agent, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane,
γ-methacryloxypropyltrimethoxysilane, N-
β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, Decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane and the like. Furthermore, as silicone oil,
Organopolysiloxane, amino-modified silicone oil, polysiloxane ammonium salt, and the like can be used. These surface treatment agents may be appropriately used in combination.

The organic fine particles are not particularly limited in their composition, and generally, vinyl organic fine particles are preferable. The reason for this is that it can be easily produced by a production method such as an emulsion polymerization method or a suspension polymerization method. Specifically, styrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene,
p-phenylstyrene, p-ethylstyrene, 2,4-
Styrene or styrene derivatives such as dimethylstyrene, pt-butylstyrene, etc., methyl methacrylate,
Ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, methacrylate derivatives such as 2-ethylhexyl methacrylate, methyl acrylate,
Ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, acrylate derivatives such as 2-ethylhexyl acrylate, ethylene,
Olefins such as propylene and isobutylene, halogenated vinyls such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, and vinylidene fluoride; vinyl esters such as vinyl propionate and vinyl acetate; vinyl methyl ether; vinyl ethyl Vinyl ethers such as ethers, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, vinyl naphthalene, vinyl pyridine and the like. Vinyl compounds, acrylonitrile, methacrylonitrile, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide, etc. Is acrylic acid or methacrylic acid derivatives. These vinyl monomers can be used alone or in combination.

The toner of the present invention is mixed with a carrier to form
It may be used as a component developer, or may be used as a one-component developer without being mixed with a carrier. However, the developer has excellent fluidity, triboelectric chargeability, etc., so that a high quality image can be stably obtained. Therefore, a two-component developer is preferably used.

<Carrier Constituting Two-Component Developer> As a carrier constituting a two-component developer, a conventionally known carrier can be used, and a carrier core serving as a core material of a resin-coated carrier may be a conventionally known carrier core. Various magnetic carrier cores can be used. For example, ferromagnetic metals such as ferrite, magnetite, and iron, cobalt, and nickel, or alloys or compounds containing these metals can be used. Here, ferrite is a general term for a magnetic oxide containing iron and a monovalent or divalent metal. Examples of the divalent metal include manganese, iron, nickel, cobalt, copper, zinc, and magnesium. And the monovalent metal includes lithium and the like. Further, magnetic particles obtained by dispersing the magnetic powder as described above in a resin may be used as a carrier core.

Vinylidene fluoride is used as the carrier core material.
Tetrafluoroethylene copolymer, tetrafluoroethylene,
A carrier coated with a fluororesin such as 2,2,2-trifluoroethyl methacrylate or pentafluoro-n-propyl methacrylate, a silicone resin, or the like can be preferably used. The volume average particle size of such a carrier is preferably in the range of 20 to 200 μm, particularly 30 to 150 μm.
The range of μm is preferred.

[0038]

EXAMPLES The present invention will be described in more detail with reference to the following examples, which should not be construed as limiting the embodiments of the present invention.

<Preparation of Colored Particles> Binder resin (styrene-acrylic resin) 100 parts by weight Colorant (carbon black) 10 parts by weight Release agent (low molecular weight polypropylene) 3 parts by weight The above components were mixed with a Henschel mixer “FM-10B”. "(Made by Mitsui Miike Koki Co., Ltd.) and kneading machine" PC
M-30 "(manufactured by Ikegai Co., Ltd.), and after cooling, pulverized by a pulverizer" IDS2 "(manufactured by Nippon Pneumatic Co., Ltd.).
2MP "(manufactured by Yaskawa-Albine K.K.) to obtain colored particles having a volume average particle size of 8.5 μm. The water content of the colored particles immediately after classification by performing all the above steps continuously,
It was 0.07 wt%.

<External Additives> Hydrophobized Primary Particle Size 7
nm fine silica particles were used.

<Model of spray nozzle set (FIG. 1)>
The types of the humidifying spray nozzle set (FIG. 1) used in the present embodiment are shown below, and all the spray nozzle sets used are manufactured by Spraying Systems Japan Co., Ltd.

<< Two-fluid spray nozzle A (siphon type): for the present invention >> Spray nozzle: 1/4 JAU-SS Liquid cap: PF1650-ss Gas cap: PA64-SS << Two-fluid spray nozzle B (external mixing type) ): For the present invention> Spray nozzle: 1/4 JAU-SS Cap for liquid: PF1650-ss Cap for gas: PA62240-60 ° << 1-fluid spray nozzle C: The present invention >> Spray nozzle: Unijet (TP type) Chip No. : 500017 (Orifice diameter 0.28m
m) <Preparation of Toners 1 to 9> Colored particles 198 immediately after the classification
0 g and 20 g of the external additive were weighed, and nine mixtures thereof were prepared. These are sequentially charged from the charging port P1 into a mixer 11 [(Henschel mixer "FM10B" (manufactured by Mitsui Miike Koki Co., Ltd.)) equipped with the humidifying spray nozzle 7 of FIG. Tip peripheral speed 40m / s
The rotation speed was adjusted to ec, and the spray nozzle 7 installed on the upper lid 14 was used as shown in Table 1 with or without humidification.
cm ² ), water pressure (kg / cm ² ), droplet diameter (μm), mixing time (minutes) and spraying time (minutes) with a stirring blade are changed to spray water droplets (without humidification). In this case, the spray was disabled) to obtain a total of nine types of toners, namely, toners 1 to 7 of the present invention and comparative toners 8 and 9 having the water contents shown in Table 1. When humidification was performed by the spray nozzle 7, humidification was started simultaneously with stirring. In addition, 16 and 17 are opening / closing means for the inlet P1 and the outlet P2.

[0043]

[Table 1]

<Measurement of Charge Amount of Toners 1 to 9> Toner 1
To 9 were determined by the following method.

After placing 1.0 g of the toner and 19 g of a fluorinated acrylate-coated ferrite carrier having a volume average particle diameter of 60 μm in a 20 cc glass bottle, and allowed to stand in an environment of 20 ° C. and 50% RH for 24 hours, a shaker “YS- LD "(manufactured by Yayoi Co., Ltd.), shaking angle 45 degrees, 200
The toner and the carrier were charged by shaking for 20 minutes at a stroke / minute. The charge amounts of the toner and the carrier were measured by a blow-off powder charge amount measuring device “TB-200” (manufactured by Toshiba Chemical Corporation). That is, 0.5 g of the mixture of the charged toner and the carrier was put into a measuring cell in which a stainless steel 400 mesh was set, and 15 g was applied using nitrogen gas at a pressure at which the internal pressure became 1.0 (kgf / cm ² ).
Blow-off for 2 seconds, the charge and mass of the scattered powder were measured, and the charge / mass (μC / g) was defined as the charge amount. The results are shown in Table 2.

<Preparation of Developers 1 to 9> 32.5 g of each of the toners 1 to 7 of the present invention and comparative toners 8 and 9 and 617.5 g of a silicone-coated ferrite carrier having a volume average particle diameter of 60 μm were mixed with 2 parts each. The developer 1 of the present invention was placed in a plastic container of 1 liter and mixed at 20 ° C. and 50% RH for 20 minutes with a mixer “YGG” (manufactured by Yayoi Co., Ltd.).
And Comparative Developers 8 and 9 were prepared.

<Image evaluation test> Developer 1 of the present invention described above
To 7 and Comparative Developers 8 and 9 were prepared using Konica U-BIX.
4355, the image was formed using a document having a solid image with a density of 1.3, the density of five random points was measured, and the average thereof was shown in Table 2 as the image density.
As for fog, the densities of five random points in the non-image area were measured, and the average thereof was shown in Table 2 as fog density. The density was measured using a Macbeth densitometer on a white background of 0.000.
, And the relative concentration was measured.

[0048]

[Table 2]

As shown in Table 2, the toner 7 for the present invention obtained by mixing the colored particles and the external additive while humidifying by spraying water droplets of water has a water content immediately after mixing of 1.35 wt%, which is an appropriate range. When this was used for image formation, a good image having a high image density was obtained. Further, the toners 1 to 6 of the present invention obtained by mixing while humidifying while controlling the droplet diameter of water using a two-fluid spray nozzle have the above water content of 0.103 to
1.95, which is within the appropriate range. In the image evaluation test, an image having a high image density and no fogging was obtained, and a more excellent image was obtained. However, the comparative toner 8 not humidified has a water content of 0.065, which is too small, so that a sufficient image density cannot be obtained in the image evaluation test. Further, the comparative toner 9 has a water content of 2.91. In the image evaluation test, there was much fog, and a clear image could not be obtained.

[0050]

As has been demonstrated in the examples, according to the method for producing the toner of the present invention and the toner obtained by the production method, an appropriate and uniform charge amount can be stably obtained, and the electrophotographic method can be used. When forming an image according to the present invention, there is an excellent effect that a clear image can be stably obtained without occurrence of fogging or reduction in image density.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of the configuration of a humidifier.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2, 8 Pressure reducing valve 3 Water tank 4 Needle valve 5 Flow meter 6, 9 Pressure gauge 7 Spray nozzle 10 Jacket 11 Mixer 12 Stirrer blade 13 Motor 14 Top lid 15 Filter 16, 17 Opening / closing means P1 Inlet P2 Outlet

Claims (3)

[Claims] 1. A method for producing a toner for developing an electrostatic charge image, which comprises a step of mixing a color particle containing at least a colorant and a binder resin with an external additive. A method for producing a toner for developing an electrostatic image, characterized by mixing by humidifying by spraying water droplets so that the water content is 0.10 to 2.0 wt%. 2. The toner for developing an electrostatic image according to claim 1, wherein the two-fluid spray nozzle sprays water droplets having a volume median diameter of 100 μm or less to humidify and mix. Production method. 3. An electrostatic image developing toner produced by the production method according to claim 1 or 2.