JP2022103861A - Toner for electrostatic charge image development and method for manufacturing the same - Google Patents

Abstract

To provide a toner for electrostatic charge image development that can prevent white streaks in both a high temperature and high humidity environment and a low temperature and low humidity environment, and can prevent the occurrence of fogging in a high temperature and high humidity environment.SOLUTION: A toner for electrostatic charge image development contains colored resin particles containing a binder resin, colorant, and mold release agent, and an external additive. When the toner is caused to pass through a sieve with an aperture of 25 μm by a wet method, of coarse particles not passing through the sieve, the number of coarse particles A with an equivalent circle diameter measured by a flow type particle image measuring device of 50 μm or more and less than 200 μm and a circularity of 0.20 or more and less than 0.97 is 1000 or more and 20000 or less in 1.0 g of toner, and the number of coarse particles B with an equivalent circle diameter measured by the flow type particle image measuring device of 50 μm or more and less than 200 μm and a circularity of 0.97 or more and 1.00 or less is less than 1000 in 1.0 g of toner.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a toner for developing an electrostatic charge image formed by an electrophotographic method, an electrostatic recording method, or the like, and a method for producing the same.

In the electrophotographic method, an electrostatic charge image formed on a photoconductor is developed with toner to obtain a visible image, and if necessary, the toner image is transferred to a transfer material such as paper or OHP, and then the toner is transferred onto the transfer material. It is a method of fixing an image to obtain a copy or a printed matter.
In an image forming apparatus such as a laser printer or a copying machine using an electrophotographic method, it is required to reduce the frequency of replacing toner cartridges. On the other hand, when the capacity of the toner cartridge is increased and the life of the toner cartridge is extended in order to reduce the frequency of replacement of the toner cartridge, if coarse particles are contained in the toner, the image quality tends to be deteriorated. Further, since the market for electrophotographic technology is rapidly expanding to emerging countries, there is a demand for toners that can obtain high-quality images even in various usage environments such as temperature and humidity.

For example, in Patent Document 1, as a method for producing a toner in which coarse particles are scarcely present, in the sieving step for removing coarse particles, the sieves are set in two upper and lower stages, and the upper sieve mesh is set to W ₁ and the lower stage. Disclosed is a method in which 1.2 ≤ W ₁ / W ₂ ≤ 1.7 is satisfied when the mesh size of the sieve is W ₂ , and the mesh of the lower sieve is made into a plain weave. According to Patent Document 1, when the toner obtained by the method is placed on a sieve having an opening of 25 μm and sucked from under the sieve, the number of coarse particles remaining on the sieve can be 200 or less per 2 g of the toner. It is described that the specific measurement results were 11 to 141 pieces.

In Patent Document 2, a wind sieving machine is used as a method of suppressing clogging of the net in the coarse powder removing step for removing the coarse powder in the toner, and the toner matrix particles and an external additive are supplied together with the mixture. The flow rate F1 [m ³ / min] of the primary air to be generated and the flow rate F2 [m ³ / min] of the secondary air supplied from the recovery port side of the coarse powder are 7 ≦ (F1 / F2) ≦ 17 Discloses a method of sieving under the conditions set forth in. Patent Document 2 describes that when 10 g of the toner obtained by the method was sieved with a 45 μm mesh sieve, the number of coarse particles remaining on the sieve was 2.2 to 11.2. Has been done.

Japanese Unexamined Patent Publication No. 2008-76873 Japanese Unexamined Patent Publication No. 2007-7944

However, it has been found that the toners disclosed in Patent Documents 1 and 2 are prone to fog when an image is formed in a high temperature and high humidity environment.
Further, as a problem when coarse particles are contained in the toner, there is a problem that so-called white streaks occur in which vertical streaks appear white in the image. White streaks are particularly likely to occur when an image is formed in a low temperature and low humidity environment.
The subject of the present disclosure is static charge image development capable of suppressing the generation of white streaks in both a high temperature and high humidity environment and a low temperature and low humidity environment, and further suppressing the generation of fog in a high temperature and high humidity environment. To provide a toner for use and a method for producing the same.

The present inventor reduces the content of the coarse particles having a relatively high circularity among the coarse particles contained in the toner, so that even if the coarse particles having a relatively low circularity are contained in a specific amount, the white streaks are formed. It has been found that it is possible to form an image in which the generation of the particles is suppressed, and further, it is found that the generation of fog can be suppressed in a high temperature and high humidity environment by containing a specific amount of coarse particles having a relatively low circularity.

The present disclosure is a toner for static charge image development containing a binder resin, colored resin particles containing a colorant and a mold release agent, and an external additive.
When the toner is passed through a sieve having an opening of 25 μm by a wet method, among the coarse particles that do not pass through the sieve, the equivalent circle diameter measured by the flow type particle image measuring device is 50 μm or more and less than 200 μm and the circularity. The number of coarse particles A in which is 0.20 or more and less than 0.97 is 1000 or more and 20000 or less in 1.0 g of toner, and the equivalent circle diameter measured by the flow type particle image measuring device is 50 μm or more and 200 μm. Provided is a static charge image developing toner in which the number of coarse particles B having less than or less than 0.97 and having a circularity of 0.97 or more and 1.00 or less is less than 1000 in 1.0 g of the toner.

In the static charge image developing toner of the present disclosure, the average circularity is preferably 0.98 or more and 1.00 or less.

The present disclosure is the method for producing the toner for static charge image development of the present disclosure.
A step of preparing a suspension in which droplets of a polymerizable monomer composition containing at least a polymerizable monomer, a colorant and a mold release agent are dispersed in an aqueous dispersion medium.
Provided is a method for producing a toner for static charge image development, which comprises a step of forming colored resin particles by subjecting the suspension to a polymerization reaction in the presence of a polymerization initiator.

The above-mentioned manufacturing method of the present disclosure further includes a step of removing a part of the coarse particles contained in the particles by supplying the particles containing the colored resin particles to the sieve using an air flow.
The sieve contains at least one mesh, and among the meshes used for the sieve, the mesh having the smallest mesh opening is 25 μm or more and 40 μm or less.
The air flow is generated by the primary air supplied together with the particles containing the colored resin particles and the secondary air supplied from the recovery port side of the coarse particles, and the flow rate of the primary air. The ratio (F1 / F2) of F1 [m ³ / min] to the flow rate F2 [m ³ / min] of the secondary air is preferably 18 or more and 50 or less.

According to the present disclosure as described above, by setting the content of the specific coarse particles A and the specific coarse particles B to the specific amounts, white streaks can be obtained in both a high temperature and high humidity environment and a low temperature and low humidity environment. It is possible to provide a toner for static charge image development capable of suppressing the generation of fogging and further suppressing the generation of fog in a high temperature and high humidity environment.

It is a schematic diagram of an example of a sieving system that can be used for manufacturing the toner for static charge image development of the present disclosure. It is a schematic diagram which shows an example of an ejector which can be suitably used in this disclosure. It is a schematic diagram which shows the laminated wire mesh arranged so that the meridian and parallel of two wire meshes having different meshes are arranged substantially parallel to each other.

In the present disclosure, "to" in the numerical range means that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.
Further, in the present disclosure, (meth) acrylate represents each of acrylate and methacrylate, (meth) acrylic represents each of acrylic and methacrylic, and (meth) acryloyl represents each of acryloyl and methacryloyl. ..

I. Toner for static charge image development The toner for static charge image development of the present disclosure (sometimes referred to simply as "toner" in the present disclosure) is a colored resin particle containing a binder resin, a colorant and a mold release agent, and a colored resin particle. Toner for static charge image development containing an external additive,
When the toner is passed through a sieve having an opening of 25 μm by a wet method, among the coarse particles that do not pass through the sieve, the equivalent circle diameter measured by the flow type particle image measuring device is 50 μm or more and less than 200 μm and the circularity. The number of coarse particles A in which is 0.20 or more and less than 0.97 is 1000 or more and 20000 or less in 1.0 g of toner, and the equivalent circle diameter measured by the flow type particle image measuring device is 50 μm or more and 200 μm. It is characterized in that the number of coarse particles B having less than or less than 0.97 and having a circularity of 0.97 or more and 1.00 or less is less than 1000 in 1.0 g of toner.

In the present disclosure, the equivalent circle diameter is the diameter of a circle having the same projected area as the particle image. In the present disclosure, the circularity is a value obtained by dividing the perimeter of a circle having the same projected area as the particle image by the perimeter of the projected image of the particle. The more complicated the surface shape of the particle, the smaller the circularity, and when the particle is a perfect sphere, the circularity is 1. In the present disclosure, the additive average of the circularity of a plurality of particles contained in the measurement sample is defined as the average circularity, and the additive average of the circle equivalent diameter is defined as the average circle equivalent diameter.
For the equivalent circle diameter, for example, a dispersion liquid in which measurement particles are dispersed is used as a sample liquid, and a flow-type particle image measuring device (for example, manufactured by Simex Co., Ltd., trade name: FPIA-3000, etc.) is used to measure the particles in the sample liquid. A projected image can be taken and the diameter of a circle equal to the projected area of the particle can be measured and obtained from the projected image. The circularity can be obtained from the projected image by measuring the peripheral length of a circle equal to the projected area of the particles and the peripheral length of the particle projected image by the following formula 1.
Calculation formula 1: (Circularity) = (Perimeter of a circle equal to the projected area of the particle) / (Perimeter of the projected image of the particle)

When the toner of the present disclosure is passed through a sieve having an opening of 25 μm by a wet method, coarse particles having a circle-equivalent diameter of 50 μm or more and less than 200 μm that does not pass through the sieve are defined as having a circle-equivalent diameter contained in the toner of the present disclosure. It is substantially the same as coarse particles of 50 μm or more and less than 200 μm. This is because coarse particles having a circle equivalent diameter of 50 μm or more cannot normally pass through a sieve having an opening of 25 μm by a wet method. Further, the coarse particles contained in the toner of the present disclosure usually have a diameter equivalent to a circle of less than 200 μm. In the toner of the present disclosure, the amount of particles having a circle equivalent diameter of less than 50 μm is not particularly limited.
In the present disclosure, as the sieve having a mesh opening of 25 μm, a mesh having a mesh opening of 25 μm in which the meridians and parallels are arranged at equal intervals and the intervals between the meridians and the parallels are the same is used.
As a method of passing the toner of the present disclosure through a sieve having an opening of 25 μm by a wet method, for example, the following method can be mentioned. First, a toner dispersion liquid in which a pre-weighed toner is dispersed in water containing a surfactant at a concentration of 0.1 to 1% by mass is passed through a sieve having an opening of 25 μm. Here, the concentration of the toner in the toner dispersion is usually about 1 to 5% by mass. Then, the water containing the surfactant is further passed through the sieve, and the water is passed through the sieve until the water passing through the sieve does not have the color of the toner with the naked eye. Next, the coarse particles remaining on the sieve are recovered with water containing a small amount of a surfactant to obtain a coarse particle dispersion. At that time, the mass of the obtained coarse particle dispersion is recorded. The particle size distribution of the coarse particle dispersion is measured using a flow-type particle image measuring device, and the number of particles of the coarse particles A and the coarse particles B is measured. The number of particles is measured for the coarse particle dispersion in the measurement cell. The number of coarse particles A contained in the coarse particle dispersion in the measurement cell NA (pieces), the number of particles _NB (pieces) of the coarse particles _B , the capacity C (g) of the measurement cell, and the entire coarse particle dispersion. From the mass _WD (g) and the mass _WT (g) of the toner used for the measurement, the number of coarse particles A contained in 1.0 g of the toner can be obtained by the following formula (A). The number of coarse particles B contained in 1.0 g of the toner can be obtained from the calculation formula (B).

In the toner of the present disclosure, the number of particles of the coarse particles A in 1.0 g of the toner is 20000 or less, and the number of particles of the coarse particles B in 1.0 g of the toner is less than 1000. In both the high temperature and high humidity environment and the low temperature and low humidity environment, it is possible to suppress the generation of white streaks and suppress the deterioration of image quality. It is considered that the white streaks are generated when the coarse particles contained in the toner are caught in the nip portion of the developing roller and the layer regulating blade in the developing device, and the toner layer on the developing roller becomes non-uniform. In addition, white streaks are more likely to occur in a low temperature and low humidity environment than in a high temperature and high humidity environment. It is presumed that the hardness of the developing roller increases in a low temperature and low humidity environment, which makes it easier for the toner to get caught in the nip portion. According to the present inventor, among the coarse particles having a circular equivalent diameter of 50 μm or more and less than 200 μm, the coarse particles B having a circularity of 0.97 or more and 1.00 or less are likely to cause white streaks, and the circularity is 0. It was found that the coarse particles A having a diameter of 20 or more and less than 0.97 are less likely to cause white streaks. In the toner of the present disclosure, the amount of the coarse particles B that are likely to cause white streaks is reduced to less than 1000 in 1.0 g of the toner, while the coarse particles that are unlikely to cause white streaks are less likely to occur. When the amount of A does not exceed 20000 particles in 1.0 g of toner, the generation of white streaks is suppressed in both a high temperature and high humidity environment and a low temperature and low humidity environment. The coarse particles A having a circularity of 0.20 or more and less than 0.97 often have a flat shape and can slip through the nip portion, so that they are difficult to be caught in the developing device and cause white streaks. It is estimated that it is difficult to become.
Further, in the toner of the present disclosure, when the number of the coarse particles A in 1.0 g of the toner is 1000 or more, it is possible to suppress the generation of fog in a high temperature and high humidity environment. It is presumed that this is because the coarse particles A contain agglomerates of an external additive such as silica. Since the coarse particles A have a large circle-equivalent diameter of 50 μm or more, they often contain agglomerates of an external additive such as silica. Further, in a high temperature and high humidity environment, the toner is less likely to be charged than in a normal temperature and humidity environment, so that fog is likely to occur. On the other hand, it is presumed that the toner of the present disclosure appropriately contains coarse particles A to improve the fluidity of the toner and suppress the generation of fog even in a high temperature and high humidity environment.
As described above, in the toner of the present disclosure, the coarse particles B that easily generate white streaks are sufficiently removed, and the coarse particles A do not generate white streaks and are in a high temperature and high humidity environment. By controlling the amount to the extent that it exerts the effect of suppressing the generation of fog, it suppresses the generation of white streaks in a high temperature and high humidity environment and a low temperature and low humidity environment, and further, in a high temperature and high humidity environment. It is considered that the occurrence of fog can be suppressed.

From the viewpoint of suppressing the generation of white streaks, the number of particles of the coarse particles A in 1.0 g of toner is preferably 19000 or less, and the number of particles of the coarse particles B in 1.0 g of toner is preferably. The number is 500 or less, more preferably 400 or less, still more preferably 350 or less.

Further, from the viewpoint of suppressing the generation of white streaks, among the coarse particles A having a circularity of 0.20 or more and less than 0.97, the particles of the coarse particles A having a circularity of 0.95 or more and less than 0.97 are particularly present. The number is preferably 500 or less, more preferably 400 or less, further preferably 300 or less, and even more preferably 200 or less in 1.0 g of the toner. The coarse particles contained in the toner of the present disclosure usually have a circularity in the range of 0.20 to 1.00.
Further, from the viewpoint of suppressing the generation of white streaks, the total number of the coarse particles A having a circularity of 0.95 or more and less than 0.97 and the total number of the coarse particles B among the coarse particles A is calculated. In 1.0 g of the toner, the number is preferably 1500 or less, more preferably 1000 or less, and further preferably 800 or less.

The toner of the present disclosure usually has an average circle-equivalent diameter of 5 to 9 μm.
The toner of the present disclosure is not particularly limited, but the average circularity is preferably 0.98 or more and 1.00 or less, and 0.99 or more and 1.00 or less, from the viewpoint of improving image reproducibility. It is more preferable to have. By producing the colored resin particles contained in the toner by a wet method such as an emulsion polymerization aggregation method, a dispersion polymerization method, a suspension polymerization method and a dissolution suspension method, the average circularity of the toner can be kept within the above range. can.
Hereinafter, a method for manufacturing the toner for static charge image development disclosed in the present disclosure will be described.
The colored resin particles contained in the toner of the present disclosure contain at least a binder resin, a colorant, and a mold release agent. Each component contained in the colored resin particles is derived from each component in the polymerizable monomer composition used in the production method described below and the polymerizable monomer for shells. The polymerizable monomer used for producing the colored resin particles is polymerized in the production process to become a polymer, and is contained in the colored resin particles as a binder resin.
Further, the external additive contained in the toner of the present disclosure is the same as the external additive used in the production method described below.

II. Method for manufacturing a toner for static charge image development The toner for static charge image development of the present disclosure includes, for example, a step of preparing colored resin particles and a step of adhering an external additive to the surface of the colored resin particles (hereinafter referred to as an external addition step). ) And a step of removing a part of the coarse particles contained in the particles by supplying the particles containing the colored resin particles to the sieve (hereinafter, may be referred to as a sieving step). It can be obtained by a production method having and.
In the present disclosure, each step of the manufacturing method may be performed in a different order as long as it is technically possible, or two or more steps may be simultaneously performed as one step.

1. 1. Step of preparing colored resin particles Generally, the method for producing colored resin particles is mainly a dry method such as a pulverization method and a wet method such as an emulsion polymerization aggregation method, a dispersion polymerization method, a suspension polymerization method and a dissolution suspension method. Be separated. The wet method is preferable because it is easy to obtain a toner having excellent printing performance such as fine line reproducibility. Among the wet methods, a polymerization method such as an emulsion polymerization aggregation method, a dispersion polymerization method, and a suspension polymerization method is preferable because it is easy to obtain a toner having a relatively small particle size distribution on the order of microns. The turbid polymerization method is more preferable.

The emulsion polymerization aggregation method is a method for producing colored resin particles by polymerizing emulsified polymerizable monomers to obtain resin fine particles and aggregating the resin fine particles with a coloring agent or the like.
Further, in the above-mentioned dissolution / suspension method, a solution in which a toner component such as a binder resin or a colorant is dissolved or dispersed in an organic solvent is formed as droplets in an aqueous medium, and the organic solvent is removed to obtain colored resin particles. It is a manufacturing method, and known methods can be used for each.

In the present disclosure, the colored resin particles can be produced by adopting a wet method or a dry method, but it is preferably produced by a suspension polymerization method which is preferable among the wet methods. As a method for producing colored resin particles by a suspension polymerization method, for example, droplets of a polymerizable monomer composition containing at least a polymerizable monomer, a colorant and a release agent are dispersed in an aqueous dispersion medium. Colored resin particles are formed by subjecting the suspension to a polymerization reaction in the presence of a polymerization initiator and a step of preparing the suspension (hereinafter, may be referred to as a step of preparing the suspension). A method having a step (hereinafter, may be referred to as a polymerization step) is preferably adopted. As the polymerizable monomer composition, one prepared in advance may be used, but it may further have a step of preparing the polymerizable monomer composition. Further, by simultaneously suspending the material of the polymerizable monomer composition while putting it into the aqueous dispersion medium, the preparation of the polymerizable monomer composition and the preparation of the suspension can be performed simultaneously in one step. You may go. Further, the method for producing colored resin particles by the suspension polymerization method may further include steps other than these.
Hereinafter, a method for producing colored resin particles by a suspension polymerization method, which comprises (1) a step of preparing a polymerizable monomer composition, (2) a step of preparing a suspension, and (3) a polymerization step. An example will be described in detail.

(1) Step of preparing a polymerizable monomer composition In this step, at least a polymerizable monomer, a colorant and a mold release agent are contained, and if necessary, a charge control agent, a polar resin and a molecular weight adjuster are contained. To prepare a polymerizable monomer composition containing other materials such as. The preparation of the polymerizable monomer composition is performed by mixing each material, and for the mixing, for example, a media type disperser is used.

[Polymerizable monomer]
In the present disclosure, the polymerizable monomer means a monomer having a functional group capable of addition polymerization. The polymerizable monomer polymerizes to form a binder resin. In the present disclosure, as the polymerizable monomer, a compound having an ethylenically unsaturated bond as a functional group capable of addition polymerization is generally used.
As the main component of the polymerizable monomer, it is preferable to use a monovinyl monomer having only one polymerizable functional group. Examples of the monovinyl monomer include styrene; styrene derivatives such as vinyltoluene and α-methylstyrene; acrylic acid and methacrylic acid; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and 2. -Acrylic acid esters such as dimethylaminoethyl acrylate; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and 2-dimethylaminoethyl methacrylate; nitriles such as acrylonitrile and methacrylonitrile. Compounds; amide compounds such as acrylamide and methacrylicamide; olefins such as ethylene, propylene and butylene;
These monovinyl monomers can be used alone or in combination of two or more. Of these, at least one selected from the group consisting of styrene, styrene derivatives, acrylic acid, acrylic acid esters, methacrylic acid and methacrylic acid esters is preferably used as the monovinyl monomer.

In order to improve the heat-resistant storage stability of the obtained toner, it is preferable to use a crosslinkable polymerizable monomer together with the monovinyl monomer. The crosslinkable polymerizable monomer is a monomer having two or more polymerizable functional groups, and is a polymerizable monomer that forms a crosslinkable bond in a resin by a polymerization reaction. Examples of the crosslinkable polymerizable monomer include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; and alcohols having two or more hydroxyl groups such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate. Ester compounds in which two or more carboxylic acids are ester-bonded; other divinyl compounds such as N, N-divinylaniline, and divinyl ether; compounds having three or more vinyl groups; and the like can be mentioned.
These crosslinkable polymerizable monomers can be used alone or in combination of two or more.
The crosslinkable polymerizable monomer is usually 0.1 to 5 parts by mass, preferably 0.3 to 2 parts by mass with respect to 100 parts by mass of the monovinyl monomer in the polymerizable monomer composition. Used in proportion.

Further, it is preferable to use a macromonomer as a part of the polymerizable monomer because the balance between the heat-resistant storage property and the low-temperature fixability of the obtained toner is improved. The macromonomer has a polymerizable carbon-carbon unsaturated double bond at the end of the molecular chain and is a reactive oligomer or polymer having a number average molecular weight of usually 1,000 to 30,000. The macromonomer preferably gives a polymer having a Tg higher than the glass transition temperature (Tg) of the polymer obtained by polymerizing the monovinyl monomer.
The macromonomer is preferably used in a proportion of 0.03 to 5 parts by mass, more preferably 0.05 to 1 part by mass with respect to 100 parts by mass of the monovinyl monomer in the polymerizable monomer composition.

The total amount of the polymerizable monomer contained in the polymerizable monomer composition is preferably 60 to 95 parts by mass, more preferably 70 to 70 parts by mass, based on 100 parts by mass of the total solid content contained in the polymerizable monomer composition. 90 parts by mass. In the present disclosure, the solid content is anything other than the solvent, and for example, a liquid monomer or the like is included in the solid content.
In the toner of the present disclosure, the content of the polymer of the polymerizable monomer is preferably 60 to 95 parts by mass, more preferably 70 to 90 parts by mass with respect to 100 parts by mass of the colored resin particles.

[Colorant]
The colorant contained in the polymerizable monomer composition is not particularly limited, and for example, black, cyan, yellow, and magenta colorants can be used.
As the black colorant, for example, carbon black, titanium black, and magnetic powders such as zinc oxide and nickel oxide can be used.
As the cyan colorant, for example, a copper phthalocyanine compound, a derivative thereof, an anthraquinone compound and the like are used, and specifically, C.I. I. Pigment Blue 2, 3, 6, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 17: 1, 60 and the like.
As the yellow colorant, for example, azo pigments such as monoazo pigments and disazo pigments, and compounds such as condensed polycyclic pigments are used. Specifically, C.I. I. Pigment Yellow 3, 12, 13, 14, 15, 17, 62, 65, 73, 74, 83, 93, 97, 120, 138, 155, 180, 181, 185, 186, and 213.
As the magenta colorant, for example, azo pigments such as monoazo pigments and disazo pigments, and compounds such as condensed polycyclic pigments are used. Specifically, C.I. I. Pigment Red 31, 48, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 149, 150, 163, 170, 184, 185, 187, 202, 206, 207, 209, 237, 238, 251, 254, 255, 269 and C.I. I. Pigment Violet 19 and the like.
In the present disclosure, these colorants can be used alone or in combination of two or more.
The colorant is preferably used in a proportion of 1 to 15 parts by mass, more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable monomer in the polymerizable monomer composition.
In the toner of the present disclosure, the content of the colorant is preferably 1 to 15 parts by mass, more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

[Release agent]
The polymerizable monomer composition contains a mold release agent from the viewpoint of improving the mold release property of the toner from the fixing roll at the time of fixing. The release agent is not particularly limited as long as it is generally used as a release agent for toner, but a monoester compound is preferably used from the viewpoint of improving the low temperature fixability of the toner.
As the monoester compound, for example, a monoester compound represented by the following formula (1) can be preferably used.
R ¹ -COO-R ² formula (1)
In the formula (1), R ¹ represents a linear alkyl group having 15 to 21 carbon atoms, and R ² represents a linear alkyl group having 16 to 22 carbon atoms. R ¹ and R ² may be the same group or may be different groups from each other. In the monoester compound represented by the formula (1), the difference between the carbon number in the raw material fatty acid (that is, the carbon number obtained by adding 1 to the carbon number of R ¹ ) and the carbon number in the raw material alcohol (that is, the carbon number of R ² ) is , 0 to 6, more preferably 4 to 6.

Examples of the monoester compound represented by the formula (1) include behenic palmitate (C ₁₅ H ₃₁ -COO-C ₂₂ H ₄₅ ) and behenic stearate (C ₁₇ H ₃₅ -COO-C ₂₂ H ₄₅ ). , Behenic acid behenic acid (C ₁₉ H ₃₉ -COO-C ₂₂ H ₄₅ ), Behenic acid behenate (C ₂₁ H ₄₃ -COO-C ₂₂ H ₄₅ ), Eikosyl palmitate (C ₁₅ H ₃₁ -COO-C ₂₀ H ₄₁ ) ), Eikosyl stearate (C ₁₇ H ₃₅ -COO-C ₂₀ H ₄₁ ), Eikosyl eikosanate (C ₁₉ H ₃₉ -COO-C ₂₀ H ₄₁ ), Eikosyl behenate (C ₂₁ H ₄₃ -COO-C ₂₀ H) ₄₁ ), stearyl stearate (C ₁₇ H ₃₅ -COO-C ₁₈ H ₃₇ ), stearyl eikosanate (C ₁₉ H ₃₉ -COO-C ₁₈ H ₃₇ ), stearyl behenate (C ₂₁ H ₄₃ -COO-C ₁₈ ). H ₃₇ ), hexadecyl eikosanate (C ₁₉ H ₃₉ -COO-C ₁₆ H ₃₃ ), hexadecyl behenate (C ₂₁ H ₄₃ -COO-C ₁₆ H ₃₃ ) and the like. Among these monoester compounds, behenic stearate, behenic palmitate, and stearyl behenate are more preferable.

The monoester compound represented by the above formula (1) is, for example, a synthesis method by an oxidation reaction, synthesis from a carboxylic acid and its derivative, an ester group introduction reaction typified by a Michael addition reaction, a carboxylic acid compound and an alcohol. It can be produced by a method utilizing a dehydration condensation reaction from a compound, a reaction between an acid halide and an alcohol compound, an ester exchange reaction, or the like. Further, a catalyst can be appropriately used for producing the monoester compound represented by the formula (1). As the catalyst, general acidic or alkaline catalysts used for the esterification reaction, for example, zinc acetate, titanium compounds and the like are preferable. After the esterification reaction, the target product may be purified by recrystallization, distillation or the like.

Examples of the release agent that can be used in the present disclosure include pentaerythritol tetrabehenate, pentaerythritol tetrapalminate, and pentaeristol tetrasteer, in addition to the monoester compound represented by the above formula (1). Pentaerythritol ester compounds such as rate, pentaerythritol tetramillistate and pentaerythritol tetralaurate, and hexaglycerin octabehenate, pentaglycerin heptabehenate, tetraglycerin hexabehenate, triglycerin pentabehenate, di. Glycerin ester compounds such as glycerin tetrabehenate and glycerin tribehenate, dipentaerythritol hexamillistate, dipentaerythritol hexapalmitate, and polyhydric alcohol esters such as dipentaerythritol hexalaurate. Ester waxes such as compounds; polyolefin waxes such as polyethylene wax and polypropylene wax, synthetic waxes such as Fishertropsh wax, hydrocarbon waxes such as petroleum waxes such as paraffin, microglycerin, and petrolatum; candelilla, carnauba, rice, wood. Natural waxes such as wax and jojoba; mineral waxes such as montan, ceresin, and ozokerite; and the like can be mentioned.
These release agents may be used alone or in combination of two or more.

The release agent used in the present disclosure has a melting point of preferably 60 to 75 ° C, more preferably 63 to 72 ° C, and even more preferably 65 to 70 ° C. When the melting point of the release agent is at least the lower limit value, the heat-resistant storage stability of the toner can be improved, and when it is at least the upper limit value, it is possible to suppress a decrease in the fixing temperature of the toner.

The acid value of the release agent used in the present disclosure is preferably 1.0 mgKOH / g or less, more preferably 0.6 mgKOH / g or less, still more preferably 0.3 mgKOH / g or less. When the acid value of the release agent is not more than the upper limit, the storage stability of the toner can be improved.

The hydroxyl value of the release agent used in the present disclosure is preferably 10 mgKOH / g or less, more preferably 6 mgKOH / g or less, still more preferably 3 mgKOH / g or less. When the hydroxyl value of the release agent is not more than the upper limit, the storage stability of the toner can be improved.
In this disclosure, the acid value and the hydroxyl value are values measured in accordance with JIS K 0070, which is a standard oil and fat analysis method established by the Japanese Industrial Standards Committee (JICS).
The mold release agent used in the present disclosure preferably has both an acid value and a hydroxyl value of not more than the above-mentioned preferable upper limit values.

The release agent is usually 8 to 40 parts by mass, preferably 11 to 35 parts by mass, and more preferably 15 to 30 parts by mass with respect to 100 parts by mass of the polymerizable monomer in the polymerizable monomer composition. Used in proportion.
In the toner of the present disclosure, the content of the release agent is usually 8 to 40 parts by mass, preferably 11 to 35 parts by mass, and more preferably 15 to 30 parts by mass with respect to 100 parts by mass of the binder resin.
When the content of the mold release agent is at least the above lower limit value, the mold release property of the toner from the fixing roll can be improved, and when it is at least the above upper limit value, the heat storage stability and durability are deteriorated. It can be suppressed.

[Charge control agent]
The polymerizable monomer composition preferably contains a positively charged or negatively charged charge control agent in order to improve the chargeability of the toner.
The charge control agent is not particularly limited as long as it is generally used as a charge control agent for toner, but among the charge control agents, it has high compatibility with the polymerizable monomer and has stable chargeability. Since (charging stability) can be imparted to the toner particles, a positively charged or negatively charged charge control resin is preferably used.

As the positively charged or negatively charged charge control resin, a functional group-containing copolymer can be used. As the positive charge control resin, for example, a functional group-containing copolymer containing a structural unit containing a functional group such as an amino group, a quaternary ammonium group or a quaternary ammonium salt-containing group can be used. , Polyamine resin, quaternary ammonium group-containing copolymer, quaternary ammonium base-containing copolymer and the like. As the negatively charged charge control resin, for example, a functional group-containing copolymer containing a structural unit containing a functional group such as a sulfonic acid group, a sulfonate-containing group, a carboxylic acid group or a carboxylic acid salt-containing group is used. Examples thereof include a sulfonic acid group-containing copolymer, a sulfonic acid group-containing copolymer, a carboxylic acid group-containing copolymer, and a carboxylic acid base-containing copolymer.
The functional group-containing copolymer used as a positively or negatively charged charge control resin is said to have high compatibility with a polymerizable monomer and excellent polymerization stability. The ratio of the functional group-containing structural unit in the functional group-containing copolymer is preferably 10% by mass or less, and more preferably 5% by mass or less. On the other hand, from the viewpoint of improving the charge stability and storage stability of the toner, the ratio of the functional group-containing structural units in the functional group-containing copolymer is preferably 0.5% by mass or more. When the charge control resin contains a sufficient functional group, the charge control resin is easily localized near the surface of the colored resin particles, and the charge control resin functions like a shell of the colored resin particles, so that the toner is used. It is estimated that the storage stability of the plastic will be improved.

The functional group-containing copolymer used as a positively or negatively charged charge control resin has high compatibility with the polymerizable monomer and is easy to adjust the charge amount by the addition amount. A styrene-acrylic resin is preferable.

Further, the functional group-containing copolymer used as a positively charged or negatively charged charge control resin preferably has a glass transition temperature (Tg) of 50 to 110 ° C, preferably 60 to 100 ° C. Is more preferable. When the glass transition temperature (Tg) of the functional group-containing copolymer is within the above range, the storage stability of the toner can be improved. Since the functional group-containing copolymer is easily localized near the surface of the colored resin particles and can function like a shell, Tg of the functional group-containing copolymer is within the above range. It is presumed that the storage stability of the toner is improved when the amount is sufficiently high.
In the present disclosure, the glass transition temperature (Tg) can be determined according to, for example, ASTM D3418-82. Specifically, the sample is heated at a heating rate of 10 ° C./min using a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd .: SSC5200), and the maximum thermal peak of the DSC curve obtained in the process is obtained. The indicated temperature can be the glass transition temperature.

Further, as the charge control agent, a charge control resin and a charge control agent other than the charge control resin may be used in combination.
Examples of other positive charge control agents include niglosin dyes, quaternary ammonium salts, triaminotriphenylmethane compounds, imidazole compounds and the like.
Examples of other negative charge control agents include azo dyes containing metals such as Cr, Co, Al, and Fe, salicylic acid metal compounds, and alkyl salicylate metal compounds.
The charge control agent may be used alone or in combination of two or more.

In the present disclosure, the charge control agent is usually 0.01 to 10 parts by mass, preferably 0.03 to 8 parts by mass with respect to 100 parts by mass of the polymerizable monomer in the polymerizable monomer composition. Used in proportion.
In the toner of the present disclosure, the content of the charge control agent is usually 0.01 to 10 parts by mass, preferably 0.03 to 8 parts by mass with respect to 100 parts by mass of the binder resin.
When the content of the charge control agent is at least the lower limit value, the generation of fog can be suppressed, and when the content is at least the upper limit value, printing stains can be suppressed.

[Polar resin]
The polymerizable monomer composition preferably contains a polar resin from the viewpoint of suppressing bleeding of the release agent. In the present disclosure, the polar resin is selected from the group consisting of polymers containing repeating units containing heteroatoms. Specific examples of the polar resin include acrylic resins, polyester resins, vinyl resins containing heteroatoms, and the like.
The polar resin may be a homopolymer or a copolymer of a heteroatom-containing monomer, or may be a copolymer of a heteroatom-containing monomer and a heteroatom-free monomer. .. When the polar resin is a copolymer of a hetero atom-containing monomer and a hetero atom-free monomer, it is easy to control the particle size of the colored resin particles, and the resulting toner bleeds the release agent. The ratio of the heteroatom-containing monomer unit to 100% by mass of all the repeating units constituting the copolymer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferable. Is 90% by mass or more.

Examples of the hetero atom-containing monomer used in the polar resin include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, sec-pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate , N-hexyl (meth) acrylate, isohexyl (meth) acrylate, neohexyl (meth) acrylate, sec-hexyl (meth) acrylate, tert-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate Alkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, dimethylaminoethyl (meth). ) Acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, 4-hydroxybutyl acrylate (meth) acrylic acid ester such as glycidyl ether, and monomer having (meth) acryloyl group such as (meth) acrylic acid. That is, (meth) acrylic monovinyl monomer; aromatic vinyl monomer containing a hetero atom such as styrene halide and styrene sulfonic acid; carboxylic acid vinyl ester monomer such as vinyl acetate; halogenation of vinyl chloride and the like. Vinyl monomer; Halogenized vinylidene monomer such as vinylidene chloride; Vinylpyridine monomer; Acrylate unsaturated carboxylic acid such as crotonic acid, acrylate, itaconic acid, fumaric acid, maleic acid, butentricarboxylic acid. Carboxy group-containing monomers such as weights; epoxy group-containing monomers such as allylglycidyl ether and the like can be mentioned. These heteroatom-containing monomers can be used alone or in combination of two or more.

Examples of the hetero atom-free monomer used in the polar resin include aromatic vinyl monomers containing no hetero atom such as styrene, vinyltoluene, α-methylstyrene, and p-methylstyrene; ethylene, propylene, and the like. Monoolefin monomers such as butylene; diene monomers such as butadiene and isoprene can be mentioned. These heteroatom-free monomers can be used alone or in combination of two or more.

The polar resin contains a polar group in which the hetero atom-containing monomer contains at least one polar group selected from a carboxyl group, a hydroxyl group, a sulfonic acid group, an amino group, a polyoxyethylene group and an epoxy group. It is preferable to contain a monomer unit because it is easy to control the particle size of the colored resin particles and it is easy to suppress the bleeding of the release agent in the obtained toner. As the polar group, at least one selected from a carboxyl group and a hydroxyl group is preferable.
Examples of the polar group-containing monomer include carboxyls of ethylenically unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, crotonic acid, silicic acid, itaconic acid, fumaric acid, maleic acid, and butentricarboxylic acid. Group-containing monomer; hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate; sulfonic acid group-containing such as styrene sulfonic acid Monomer; Amino group-containing monomer such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; Polyoxyethylene group-containing monomer such as methoxypolyethylene glycol (meth) acrylate; Glycidyl (meth) acrylate , Epoxy group-containing monomers such as allyl glycidyl ether and 4-hydroxybutyl acrylate glycidyl ether can be mentioned. These polar group-containing monomers can be used alone or in combination of two or more.
When the polar resin contains a polar group-containing monomer unit, the polar resin is located at the end of the main chain or side chain, or is bonded to the main chain or side chain in a pendant shape. Is preferable because it is easy to be arranged on the surface of the droplets of the polymerizable monomer composition, it is easy to control the particle size of the colored resin particles, and it is easy to suppress the bleeding of the mold release agent in the obtained toner.

When the polar resin does not contain the polar group-containing monomer unit, the hetero atom-containing monomer unit contained in the polar resin has high compatibility with the polymerizable monomer and is colored resin particles. It is preferable to contain a monomer unit derived from an alkyl (meth) acrylate because it is easy to control the particle size of the syrup and it is easy to suppress the bleeding of the release agent in the obtained toner. , The alkyl group more preferably contains a monomer unit derived from an alkyl (meth) acrylate having 3 or less carbon atoms, and is simply derived from at least one selected from methyl (meth) acrylate and ethyl (meth) acrylate. It is more preferable to contain a metric unit, and even more preferably to contain a monomer unit derived from methyl (meth) acrylate.

The polar resin has high compatibility with the polymerizable monomer, is easy to control the particle size of the colored resin particles, and is easy to suppress bleeding of the release agent in the obtained toner. A copolymer of at least one selected from acrylic acid ester and methacrylic acid ester and at least one selected from acrylic acid and methacrylic acid is preferable, and the copolymer of acrylic acid ester, methacrylic acid ester, and acrylic acid is preferable. Coalescence is more preferred. In the present disclosure, such a copolymer of (meth) acrylic acid ester and (meth) acrylic acid may be referred to as an acrylic copolymer.
In the acrylic copolymer, examples of the (meth) acrylic acid ester include the same as the (meth) acrylic acid ester used for the heteroatom-containing monomer. In the acrylic copolymer, the (meth) acrylic acid ester may or may not contain the polar group, but the one not containing the polar group is preferable, and among them, alkyl. (Meta) acrylate is preferred. The acrylic acid ester used in the acrylic copolymer is preferably at least one selected from the group consisting of ethyl acrylate, n-propyl acrylate, isopropyl acrylate and n-butyl acrylate, and more preferably. At least one selected from ethyl acrylate and n-butyl methacrylate. The methacrylic acid ester used in the acrylic copolymer is preferably at least one selected from the group consisting of methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate and n-butyl methacrylate, and more preferably. It is methyl methacrylate.

The acrylic copolymer has high compatibility with the polymerizable monomer, and it is easy to control the particle size of the colored resin particles, and it is easy to suppress the bleeding of the release agent in the obtained toner. The ratio of (meth) acrylic acid to 100% by mass of the total amount of (meth) acrylic acid ester and (meth) acrylic acid used in the synthesis of the acrylic copolymer is preferably 0.05 to 1% by mass. It is more preferably 0.1 to 0.6% by mass, and even more preferably 0.3 to 0.5% by mass.

The acrylic copolymer has high compatibility with the polymerizable monomer, and it is easy to control the particle size of the colored resin particles, and it is easy to suppress the bleeding of the release agent in the obtained toner. It is preferable that the copolymer is a monomer containing 50.0% by mass or more of methyl methacrylate with respect to 100% by mass of the total mass of the monomers used for synthesizing the copolymer. The acrylic copolymer is more preferably a monomer copolymer containing 50.0 to 99.9% by mass of methyl methacrylate and 0.1 to 5.0% by mass of (meth) acrylic acid. Yes, more preferably, it is a copolymer of a monomer containing 50.0 to 99.0% by mass of methyl methacrylate and 0.1 to 5.0% by mass of (meth) acrylic acid, and even more preferably. , Methyl methacrylate 50.0 to 98.0% by mass, alkyl (meth) acrylate different from methyl methacrylate 1.0 to 5.0% by mass, and (meth) acrylic acid 0.1 to 5.0% by mass. It is a copolymer of a monomer containing, and is particularly preferably 50.0 to 98.0% by mass of methyl methacrylate and 1.0 to 5.0% by mass of an alkyl (meth) acrylate different from methyl methacrylate. (Meta) A monomer copolymer containing 0.2 to 3.0 mass of acrylic acid.
As the alkyl (meth) acrylate different from methyl methacrylate, at least one selected from ethyl acrylate and butyl acrylate is preferable because the glass transition point can be controlled.

The acrylic copolymer may contain a small amount of monomer units derived from other monomers different from both the (meth) acrylic acid ester and the (meth) acrylic acid. The content ratio of the other monomers is used for the synthesis of the acrylic copolymer because it is easy to control the particle size of the colored resin particles and the bleeding of the release agent is easily suppressed in the obtained toner. The total amount of the monomers to be obtained is preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, and most preferably not containing the other monomers.
Examples of the other monomer include the heteroatom-free monomer and the heteroatom-containing monomer other than the (meth) acrylic monovinyl monomer.

The acid value of the polar resin is preferably 0.5 to 7.0 mgKOH / g, more preferably 1.0 to 5.0 mgKOH / g, and even more preferably 1.5 to 3.0 mgKOH / g. be. When the acid value of the polar resin is at least the lower limit, the heat-resistant storage stability, low-temperature fixability, and printing durability of the toner can be improved. When the acid value of the polar resin is not more than the upper limit, the particle size of the colored resin particles can be easily controlled.

The weight average molecular weight (Mw) of the polar resin is usually 6,000 to 50,000, preferably 8,000 to 45,000, more preferably 9,000 to 45,000, still more preferably 10,000 to. It is 40,000. When the weight average molecular weight (Mw) of the polar resin is at least the lower limit value, the heat-resistant storage stability and durability of the toner can be improved, and when it is at least the upper limit value, the fixing temperature of the toner is increased. Can be suppressed.
In the present disclosure, the weight average molecular weight (Mw) of the polymer can be determined by GPC in terms of polystyrene using a sample dissolved in tetrahydrofuran (THF).

The glass transition temperature (Tg) of the polar resin is preferably 60 to 95 ° C, more preferably 65 to 90 ° C, still more preferably 65 to 85 ° C, still more preferably 70 to 80 ° C.
When the glass transition temperature of the polar resin is at least the lower limit value, the heat-resistant storage stability of the toner can be improved, and when it is at least the upper limit value, the low temperature fixability of the toner can be improved.

As the polar resin, a commercially available one can be used, but the monomer containing the heteroatom-containing monomer is subjected to a solution polymerization method, an aqueous solution polymerization method, an ion polymerization method, a high-temperature high-pressure polymerization method, or a suspension weight. It can be produced by polymerizing by a known method such as legal.
When the polar resin is a copolymer, the copolymer may be a random copolymer, a block copolymer, or a graft copolymer, but it may be a random copolymer. preferable.
Further, the polar resin is preferably finely pulverized from the viewpoint of improving the solubility.

The content of the polar resin is preferably 0.8 to 2.5 parts by mass, more preferably 1.0 to 2 parts by mass with respect to 100 parts by mass of the polymerizable monomer in the polymerizable monomer composition. It is 2 parts by mass, more preferably 1.0 to 2.0 parts by mass.
In the toner of the present disclosure, the content of the polar resin is preferably 0.8 to 2.5 parts by mass, more preferably 1.0 to 2.2 parts by mass, and further, with respect to 100 parts by mass of the binder resin. It is preferably 1.0 to 2.0 parts by mass.
When the content of the polar resin is at least the lower limit, it is easy to control the particle size of the colored resin particles, the bleeding of the release agent can be suppressed in the obtained toner, and the heat-resistant storage property is further maintained. And the balance of low temperature fixability can be improved, and the printing durability can be improved. On the other hand, when the content of the polar resin is not more than the upper limit value, it is possible to suppress an increase in the fixing temperature of the toner.

[Molecular weight adjuster]
The polymerizable monomer composition preferably further contains a molecular weight modifier. The molecular weight adjusting agent is not particularly limited as long as it is generally used as a molecular weight adjusting agent for toner, and is, for example, t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, 2, 2, 4 , 6,6-Pentamethylheptane-4-thiol and other mercaptans; tetramethylthium disulfide, tetraethylthium disulfide, tetrabutyltiuram disulfide, N, N'-dimethyl-N, N'-diphenylthium disulfide, N, N '-Dioctadecyl-N, N'-thiolam disulfides such as diisopropyl thiuram disulfide; and the like. These molecular weight adjusting agents may be used alone or in combination of two or more.
The molecular weight adjusting agent is usually used in a ratio of 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymerizable monomer in the polymerizable monomer composition.

(2) Step of preparing a suspension In this step, the polymerizable monomer composition obtained by the above-mentioned step is granulated in an aqueous dispersion medium, and droplets of the polymerizable monomer composition are formed. This is a step of preparing a dispersed suspension.

The aqueous dispersion medium used in this step includes at least an aqueous medium. In the present disclosure, the aqueous medium is a medium selected from the group consisting of a hydrophilic solvent such as water, a lower alcohol and a lower ketone, and a mixture of water and a hydrophilic solvent, and is a medium containing water as a main component. It is preferable, and water alone may be used. As the water, ion-exchanged water is usually used. When a hydrophilic solvent is used, it is preferable to adjust the content of the hydrophilic solvent within a range that does not inhibit the polymerization.
The aqueous medium is usually used in a proportion of 100 to 3000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymerizable monomer in the polymerizable monomer composition.

The aqueous dispersion medium preferably contains a dispersion stabilizer. Examples of the dispersion stabilizer include sulfates such as barium sulfate and calcium sulfate; carbonates such as barium carbonate, calcium carbonate, and magnesium carbonate; phosphates such as calcium phosphate; metals such as aluminum oxide and titanium oxide. Oxides; metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and ferric hydroxide; inorganic compounds such as, and water-soluble polymers such as polyvinyl alcohol, methylcellulose, and gelatin; anionic surfactants; Examples thereof include organic compounds such as nonionic surfactants; amphoteric surfactants; These dispersion stabilizers can be used alone or in combination of two or more.
Among the above dispersion stabilizers, an inorganic compound, particularly a colloid of a poorly water-soluble metal hydroxide is preferable. By using an inorganic compound, particularly a colloid of a poorly water-soluble metal hydroxide, the particle size distribution of the colored resin particles can be narrowed, and the residual amount of the dispersion stabilizer after washing can be reduced. The resulting toner can reproduce the image clearly and has excellent environmental stability. Further, the aqueous dispersion medium is preferably a colloid in which a poorly water-soluble inorganic compound is dispersed in a solvent.
In the present disclosure, the poorly water-soluble inorganic compound is preferably an inorganic compound having a solubility in 100 g of water of 0.5 g or less.
The dispersion stabilizer is usually used in a ratio of 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer in the polymerizable monomer composition.

In this step, when the polymerizable monomer composition is granulated in the aqueous dispersion medium, a polymerization initiator is added to the mixed solution of the polymerizable monomer composition and the aqueous dispersion medium to make the polymerizable monomer composition polymerizable. It is preferable to form droplets of the monomer composition. The polymerization initiator may be added after the polymerizable monomer composition is dispersed in the aqueous dispersion medium and before the droplets are formed, but the polymerization initiator is not dispersed in the aqueous dispersion medium. It may be added to the polymer composition.
Examples of the polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate: 4,4'-azobis (4-cyanovaleric acid) and 2,2'-azobis (2-methyl-N- (2-methyl-N-). Hydroxyethyl) propionamide), 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis (2,4-dimethylvaleronitrile), and 2,2'-azobisisobutyronitrile And other azo compounds; di-t-butyl peroxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxydiethylacetate, t-hexylperoxy-2-ethylbutanoate. , Diisopropylperoxydicarbonate, di-t-butylperoxyisobutyrate, organic peroxides such as t-butylperoxyisobutyrate and the like. These polymerization initiators can be used alone or in combination of two or more.
Among these polymerization initiators, organic peroxides are preferable because the amount of residual polymerizable monomers can be reduced and the printing durability of the toner can be improved. Among the organic peroxides, the peroxy ester is preferable because the initiator efficiency is good and the residual polymerizable monomer can be reduced, and the non-aromatic peroxy ester, that is, the peroxy ester having no aromatic ring is more preferable. ..

Further, in the step of preparing the suspension, a disperser having a combination of a rotor and a stator, which is a comb-tooth type concentric ring, and a stirring device having a dispersion liquid supply tank are used, and the aqueous dispersion medium is used. And the dispersion liquid containing the polymerizable monomer composition is repeatedly supplied from the dispersion liquid supply tank to the disperser, stirred by the disperser, and then discharged to the dispersion liquid supply tank. The suspension is prepared by circulating in the stirring device, the peripheral speed of the rotor of the disperser is 15 to 40 m / s, and the circulation of the dispersion liquid calculated by the following formula (I). The number of times is preferably 4 to 30.
Equation (I)
Number of times the dispersion liquid is circulated = {Flow rate of the dispersion liquid (liter / h) x processing time (h)} / Amount of the dispersion liquid charged (liter)
Here, the peripheral speed of the rotor means the tip speed of the rotor. The number of times the dispersion liquid is circulated means the number of times the dispersion liquid circulates in the disperser. That is, by multiplying the flow rate (liter / h) of the dispersion liquid in the disperser by the processing time (h) by the disperser, the total amount of processing processed by the disperser can be obtained. By dividing this total processing amount by the amount of the dispersion liquid charged (liter), the number of circulations of the dispersion liquid can be calculated.
By setting the peripheral speed of the rotor to 15 m / s or more and the number of circulations to 4 or more, the particle size distribution of the colored resin particles can be narrowed. Further, by setting the number of circulations to 30 or less, deterioration of toner productivity can be suppressed. Further, from the viewpoint of convenience that a general disperser can be used, the peripheral speed of the rotor is preferably 40 m / s or less.
The peripheral speed of the rotor is preferably 15 to 35 m / s, more preferably 15 to 30 m / s, and even more preferably 15 to 25 m / s.
The number of circulations is more preferably 10 to 25, still more preferably 10 to 20.

In the disperser included in the stirrer, the rotor is rotated at high speed to flow the dispersion liquid from the inside of the rotor to the outside of the stator, and the dispersion liquid is stirred in the gap between the rotor and the stator. .. The combination of the rotor and the stator contained in the dispersion may be one-step or multi-step of two or more steps. From the viewpoint of narrowing the particle size distribution of the obtained colored resin particles, it is preferably multi-step, more preferably two-step or three-step, and particularly preferably three-step. The number of layers of the rotor and the stator in the combination of the rotor and the stator, and the number of teeth of the rotor and the stator are appropriately selected according to the particle size of the toner to be manufactured, and are not particularly limited. When the combination of the rotor and the stator is arranged in multiple stages, the number of teeth of the rotor and the stator closest to the inlet side of the dispersion is smaller than the number of teeth of the other rotors and the stator. It is preferable that they are arranged in such a manner. For example, the arrangement of the combination of the rotor and the stator in the disperser is three stages in the order of coarse teeth, middle teeth, and fine teeth from the injection port side to the outlet side of the dispersion liquid, coarse teeth, middle teeth, and so on. Either three stages in the order of middle teeth, three stages in the order of coarse teeth, fine teeth, fine teeth, two stages in the order of coarse teeth, middle teeth, and two stages in the order of coarse teeth, fine teeth. It is preferable to have.

In the stirring device, for example, when the dispersion liquid containing the aqueous dispersion medium and the polymerizable monomer composition is injected into the dispersion liquid supply tank, the dispersion liquid is transferred from the dispersion liquid supply tank to the disperser. It is supplied, stirred by the disperser, and then repeatedly discharged to the dispersion liquid supply tank, circulated in the stirrer, and then supplied to the polymerization reactor.
The method of feeding the dispersion liquid is not particularly limited, and examples thereof include a method using a liquid feeding pump. Further, the internal pressure of the disperser can be adjusted by adjusting the flow rate of the dispersion liquid discharged from the disperser. The internal pressure of the disperser is preferably 0.01 to 15 MPa, more preferably 0.05 to 10 MPa, still more preferably 0.1 to 5 MPa. By keeping the internal pressure of the disperser within the above range, it is possible to efficiently form fine droplets while suppressing the generation of bubbles due to cavitation.

In the stirring device used in the manufacturing method of the present disclosure, the rotation axis of the disperser may be a horizontal type extending along the horizontal direction or a vertical type extending along the direction of gravity. ..
In the manufacturing method of the present disclosure, a commercially available stirrer can be used. For example, a horizontal multi-stage inline disperser such as a milder (: product name) manufactured by Pacific Machinery & Engineering Co., Ltd., a Cavitron (: product name) manufactured by Eurotech Co., Ltd., and an inline disperser manufactured by IKA (for example, DISPAX-RECTOR). (Registered trademark) DRS (: trade name), etc.) and the like can be mentioned as a vertical multi-stage in-line disperser.

(3) Polymerization Step In this step, colored resin particles are formed by subjecting the suspension obtained in the above-mentioned step to a polymerization reaction.
It is preferable to further add a water-soluble oxoacid salt to the suspension during the polymerization reaction. By adding a water-soluble oxoacid salt at the time of polymerization, the aggregation of droplets and the generation of fine powder can be suppressed, and the particle size distribution can be narrowed. Examples of the water-soluble oxolate salt include borates, phosphates, sulfates, carbonates, silicates, nitrates and the like, and preferably at least selected from the group consisting of borates and phosphates. One type, more preferably borate, is used. Examples of the borate include sodium tetrahydroborate, potassium tetrahydroborate, sodium tetraborate, sodium metaborate, sodium metaborate, sodium peroxoborate, potassium metaborate, and hydrates of these borates. Can be mentioned. Examples of the phosphate include sodium phosphinate, sodium phosphonate, sodium hydrogen phosphonate, sodium phosphate, disodium hydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, sodium hexametaphosphate, and hypophosphate. Sodium, sodium diphosphate, disodium dihydrogen phosphate, sodium triphosphate, cyclo-sodium tetraphosphate, potassium phosphinate, potassium phosphonate, potassium hydrogen phosphonate, potassium phosphate, dipotassium hydrogen phosphate, Examples thereof include potassium dihydrogen phosphate, potassium diphosphate, potassium metaphosphate, and hydrates of these phosphates. Among the borates, sodium tetraborate, sodium metaborate, sodium metaborate, and hydrates of these borates are preferable, and sodium tetraborate decahydrate is particularly preferable.
The water-soluble oxoacid salt is usually used in a proportion of 0.1 to 1,000 parts by mass, preferably 1 to 100 parts by mass, based on 100 parts by mass of the inorganic compound used as the dispersion stabilizer. Used.

The polymerization temperature when the suspension is subjected to the polymerization reaction is not particularly limited, but is preferably 50 ° C. or higher, and more preferably 60 to 95 ° C. The time of the polymerization reaction is preferably 1 hour to 20 hours, more preferably 2 hours to 15 hours.

The colored resin particles obtained by subjecting the suspension to the polymerization reaction may be used as a polymerization toner by adding an external additive as they are, but the colored resin particles are also referred to as a so-called core-shell type (or "capsule type"). ) Is preferably used as the core layer of the colored resin particles. The core-shell type colored resin particles have a structure in which the outside of the core layer is coated with a shell layer formed of a material different from the core layer. By coating the core layer made of a material having a low softening point with a material having a higher softening point, it is possible to balance the lowering of the fixing temperature of the toner and the prevention of aggregation during storage.

The method for producing the core-shell type colored resin particles using the colored resin particles obtained by subjecting the suspension to the polymerization reaction is not particularly limited, and can be produced by a conventionally known method. The in situ polymerization method and the phase separation method are preferable from the viewpoint of production efficiency.

A method for producing core-shell type colored resin particles by the in situ polymerization method will be described below.
A polymerizable monomer (polymerizable monomer for shell) and a polymerization initiator for forming a shell layer are added to a dispersion liquid in which colored resin particles obtained by subjecting the suspension to a polymerization reaction are dispersed. By polymerizing, core-shell type colored resin particles can be obtained.

As the polymerizable monomer for the shell, the same polymerizable monomer as described above can be used. Among them, it is preferable to use monomers such as styrene, acrylonitrile, and methyl methacrylate, which can obtain a polymer having a Tg of more than 80 ° C., alone or in combination of two or more.
The amount of the polymerizable monomer for shells added is not particularly limited, but is usually 1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable monomer used for the core layer. The binding resin of the core-shell type colored resin particles includes the binding resin in the core layer and the binding resin in the shell layer.

Examples of the polymerization initiator used for the polymerization of the polymerizable monomer for shells include metal persulfates such as potassium persulfate and ammonium persulfate; 2,2'-azobis (2-methyl-N- (2-hydroxyethyl)). ) Propionamide), and azo-based initiators such as 2,2'-azobis- (2-methyl-N- (1,1-bis (hydroxymethyl) 2-hydroxyethyl) propionamide); etc. A polymerization initiator can be mentioned. These can be used alone or in combination of two or more. The amount of the polymerization initiator is preferably 0.1 to 30 parts by mass, and more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer for the shell.

The polymerization temperature of the shell layer is preferably 50 ° C. or higher, more preferably 60 to 95 ° C. The time of the polymerization reaction is preferably 1 to 20 hours, more preferably 2 to 15 hours.

(4) Washing, Filtration, Dehydration, and Drying Steps In the production method of the present disclosure, the aqueous dispersion of colored resin particles obtained by the polymerization step is washed, filtered, dehydrated, and dried according to a conventional method. It is preferable to further have a step of repeating the process several times as needed.

The washing is performed to remove the poorly water-soluble inorganic compound from the aqueous dispersion of the colored resin particles obtained by the polymerization step when the poorly water-soluble inorganic compound is used as the dispersion stabilizer. Examples of the cleaning method include a method of dissolving a poorly water-soluble inorganic compound in water and removing it by adding an acid or an alkali to an aqueous dispersion of colored resin particles. Above all, it is preferable to add an acid to adjust the pH of the aqueous dispersion of the colored resin particles to 6.5 or less. As the acid to be added, inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid, and organic acids such as formic acid and acetic acid can be used, but they are particularly efficient in removing them and have a small burden on the manufacturing equipment. Sulfuric acid is suitable.

Various known methods and the like can be used for dehydration and filtration, and the method is not particularly limited. For example, a centrifugal filtration method, a vacuum filtration method, a pressure filtration method and the like can be mentioned. Further, the drying method is not particularly limited, and various methods can be used.
When the external addition step described later is performed before the sieving step, the colored resin particles can be dried together with the adhesion of the external additive in the external addition step. Therefore, the colored resin particles before the external addition step can be used. It may be dried so that the water content is about 7 to 20%.

The colored resin particles obtained through the above steps have a volume average particle size (Dv) of preferably 3 to 15 μm, more preferably 4 to 12 μm. When Dv is at least the above lower limit value, the fluidity of the toner can be improved, and deterioration of transferability and deterioration of image density can be suppressed. When Dv is equal to or less than the upper limit value, it is possible to suppress a decrease in the resolution of the formed image.

The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of the colored resin particles is preferably 1.0 to 1.3, and more preferably 1. It is 0 to 1.2. When Dv / Dn is 1.3 or less, deterioration of transferability, image density and resolution can be suppressed. The volume average particle size and the number average particle size of the colored resin particles can be measured using, for example, a particle size analyzer (manufactured by Beckman Coulter, trade name: Multisizer) or the like.

The average circularity of the colored resin particles is preferably 0.96 to 1.00, more preferably 0.97 to 1.00, and 0.98 to 1.00 from the viewpoint of image reproducibility. Is more preferable.
The closer the average circularity of the colored resin particles is to 1.00, the more the fine line reproducibility of printing can be improved. The average circularity of the colored resin particles can be obtained in the same manner as the average circularity of the toner.

2. 2. External addition step The external addition step is a step of adhering an external additive to the surface of the colored resin particles. The colored resin particles to which the external additive is attached may be colored resin particles before the sieving step described later, or may be colored resin particles obtained after the sieving step. Alternatively, before performing the sieving step, a first externaling step of adhering a part of the external additive to the colored resin particles is performed, and after performing the sieving step, the external additive is further added to the obtained particles. A second external addition step for adhering may be performed. In the method for producing the toner of the present disclosure, at least a part of the external additive is applied to the colored resin particles before the sieving step from the viewpoint of improving the fluidity of the particles supplied to the sieving in the sieving step described later. It is preferable to attach it to the surface.

The external addition step is performed, for example, by mixing and stirring the colored resin particles together with the external additive to perform the external addition treatment.
The stirrer for performing the external addition treatment is not particularly limited as long as it is a stirrer capable of adhering the external additive to the surface of the colored resin particles. (: Product name, manufactured by Nippon Coke Industries Co., Ltd.), Super Mixer (: Product name, manufactured by Kawada Seisakusho Co., Ltd.), Q Mixer (: Product name, manufactured by Nippon Coke Industries Co., Ltd.), Mechanofusion System (: Product name, manufactured by Hosokawa Micron Co., Ltd.) ), And a stirrer capable of mixing and stirring such as Mechanomill (trade name, manufactured by Okada Seiko Co., Ltd.) can be used for external addition treatment.
Further, in the external addition treatment performed before the sieving step, the external addition treatment is performed by drying the colored resin particles having a water content of about 7 to 20% and the external additive while mixing and stirring using the above-mentioned stirrer. This is preferable in that the drying time of the colored resin particles can be shortened because the fluidity of the colored resin particles during drying is improved.

Examples of the external additive include inorganic fine particles such as silica, titanium oxide, aluminum oxide, zinc oxide, tin oxide, barium titanate, strontium titanate, calcium carbonate, calcium phosphate and cerium oxide; polystyrene resin, polymethyl methacrylate resin and the like. (Meta) acrylic acid ester resin, styrene- (meth) acrylate copolymer, silicone resin, melamine resin, zinc stearate, organic fine particles such as calcium stearate; and the like. The organic fine particles may be core-shell type particles such that the core contains a (meth) acrylic acid ester resin and the shell contains a polystyrene resin. Among these, inorganic fine particles are preferable, and among the inorganic fine particles, at least one fine particle selected from silica and titanium oxide is preferable, and silica fine particles are more preferable.
Although each of these external additives can be used alone, it is preferable to use two or more of them in combination.
The external additive used in the present disclosure preferably contains hydrophobized fine particles, more preferably contains hydrophobicized inorganic fine particles, and even more preferably contains hydrophobized silica fine particles. When the colored resin particles are dried together with the external addition treatment, the external additive added at the time of drying preferably contains hydrophobic fine particles from the viewpoint of improving the drying efficiency, and the hydrophobic inorganic fine particles are preferable. It is more preferable to contain silica fine particles which have been hydrophobized.
Further, from the viewpoint of improving the charging characteristics, it is also preferable to use hydrophobic silica fine particles and organic fine particles in combination as an external additive.

The average primary particle size of the number of external additives used in the present disclosure is not particularly limited, but is preferably 5 to 100 nm because the number of coarse particles A contained in the toner can be easily adjusted to the specific amount. Yes, more preferably 5 to 50 nm.
When the colored resin particles are dried together with the external addition treatment, the average primary particle size of the number of external additives added during drying is preferably 5 nm to 30 nm, preferably 5 nm to 15 nm, from the viewpoint of improving the drying efficiency. Is more preferable.

From the viewpoint that the number of coarse particles A contained in the toner can be easily adjusted to the specific amount, the amount of the external additive added is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the colored resin particles. More preferably, it is 0.2 to 4 parts by mass. Further, when the amount of the external additive added is not less than the lower limit value, the generation of transfer residue can be suppressed, and when it is not more than the upper limit value, fog can be suppressed.
When the colored resin particles are dried together with the external addition treatment, the amount of the external additive added at the time of drying is preferably 0. With respect to 100 parts by mass of the colored resin particles, from the viewpoint of improving the drying efficiency. It is 1 to 1 part by mass, more preferably 0.1 to 0.5 part by mass.

3. 3. Sieving step The sieving step is a step of removing a part of the coarse particles contained in the particles by supplying the particles containing the colored resin particles to the sieve after obtaining the colored resin particles. By the sieving step, the number of the coarse particles A and the coarse particles B in the toner can be controlled as described above.

The sieving step may be performed after the step of preparing the colored resin particles, may be performed before the external addition step, may be performed after the external addition step, and as described above, the first outer layer may be performed. After the addition step, a sieving step may be performed, and then a second external addition step may be further performed. When the sieving step is performed before the external addition step, the particles supplied to the sieve are particles containing at least colored resin particles, and when the sieving step is performed after the external addition step, the particles supplied to the sieve are at least. It is a mixed particle containing colored resin particles and an external additive.

As the sieve used in the sieving step, for example, a wire net such as a stainless steel net or a net such as a resin net such as a nylon net, a polyester net, or a polypropylene net can be used. A metal net is preferable because the wire of the net does not easily expand and contract, and it is easy to maintain the size of the opening even in long-term use. A resin net is preferable because the wire of the net expands and contracts appropriately, so that coarse particles having a particle size close to the opening are less likely to pierce the net, and the processing capacity during use is less likely to decrease. Further, the net wire is preferably one that has been subjected to antistatic treatment.

In the sieving step, as the net used for sieving, a net in which the meridians and parallels are arranged at equal intervals and the intervals between the meridians and the parallels are the same is used. In a net in which the meridians and parallels are arranged at equal intervals and the intervals between the meridians and the parallels are the same, the openings based on the latitude lines and the parallels are the same. It is the same regardless of the location of the net except for the error.
The weaving method of the net used for the sieve is preferably one in which the meridians and parallels are orthogonal to each other, and may be, for example, a general weaving method such as plain weave, twill weave, and ton cap weave. Of these, plain weave is preferable because it is easy to maintain the size of the opening and it is possible to efficiently remove desired coarse particles.

In the present disclosure, the sieving step is a step of removing some of the coarse particles contained in the particles by supplying the particles containing the colored resin particles to the sieve using an air flow.
The sieve contains at least one mesh, and among the meshes used for the sieve, the mesh having the smallest mesh opening is 25 μm or more and 40 μm or less.
The air flow is generated by the primary air supplied together with the particles containing the colored resin particles and the secondary air supplied from the recovery port side of the coarse particles, and the flow rate of the primary air. A sieving step in which the ratio (F1 / F2) of F1 [m ³ / min] to the flow rate F2 [m ³ / min] of the secondary air is 18 or more and 50 or less is preferable.
By the preferred sieving step, the number of coarse particles A and the number of coarse particles B in the toner can be easily set to the above-mentioned number of particles.
When the particles are supplied to the sieve using an air stream, the coarse particles caught on the sieve may be pushed by the air stream and pass through the sieve. In particular, coarse particles having a low circularity often have a flat shape, so even if they are caught on the sieve once, they are easily pushed by the air flow and pass through the sieve. In the preferred sieving step described above, in the method of supplying particles to the sieving using an air flow, the mesh of the mesh used for the sieving and the flow rate F1 of the primary air and the flow rate F2 of the secondary air for generating the air flow are used. By adjusting the above, the coarse particles A having a relatively low circularity can be appropriately passed through the sieve, and the coarse particles B having a relatively high circularity can be prevented from passing through the sieve. It is estimated that the number of coarse particles A and the number of coarse particles B in 1.0 g of the toner can be easily controlled to the above-mentioned number of particles by efficiently removing B and leaving the coarse particles A appropriately. Will be done.

The sieving machine capable of supplying the powder to be treated to the sieving using an air flow is not particularly limited, and examples thereof include a blow-through type sieving machine and a wind sieving machine. Among them, a blow-through type sieving machine is preferably used because it is easy to control the number of coarse particles A and B in the toner to the above-mentioned number of particles and the recovery rate is excellent.
Examples of commercially available blow-through type sieving machines include high bolters (trade name, manufactured by Toyo Hi-Tech Co., Ltd.) and spin air sheep (trade name, manufactured by Seishin Corporation).
In order to generate an air flow by the primary air supplied together with the powder to be treated and the secondary air supplied from the recovery port side of the coarse particles, for example, as a sieving machine, from the net product recovery port to the net side. A sieving machine provided with a secondary air intake mechanism for introducing secondary air may be used. The secondary air intake mechanism is a mechanism for winding the powder recovered as a net product on the net side and sieving it again.

FIG. 1 shows a schematic diagram of an example of a sieving system that can be used for manufacturing the toner for static charge image development of the present disclosure. In the sieving system shown in FIG. 1, the particles are supplied to the sieving machine 13 by the primary air supplied by the primary air intake mechanism 12 from the feeder 11 that supplies the particles containing the colored resin particles. Of the particles supplied to the sieving machine 13, the particles that did not pass through the net 14 included in the sieving machine 13 are the secondary air introduced by the secondary air intake mechanism 16 while passing through the coarse particle drop port 15. Either it is wound up again on the mesh 14 side, or it passes through the coarse particle drop port 15 and is collected in the coarse particle recovery container 17. The secondary air intake mechanism 16 is provided with a flow rate adjusting valve 22 for adjusting the flow rate of air. Among the particles supplied to the sieving machine 13, the particles that have passed through the net 14 are collected in the collection container 20 through the pipe 18 and the cyclone 19 on the air flow by the blower 21.

Further, in the sieving step, it is preferable that the particles containing the colored resin particles are dispersed and supplied to the sieve via the ejector 1 as shown in FIG. The ejector 1 is a disperser in which compressed air is blown out from an air blowing nozzle 2, partially evacuated, and the powder fluid 4 is sucked from the powder fluid suction nozzle 3 to be dispersed and supplied. By using the ejector 1, the particles containing the colored resin particles can be uniformly supplied to the sieve, and the life of the sieve can be extended.

In the above preferable sieving step, the mesh size of the mesh having the smallest mesh size among the meshes used for sieving is set to 25 μm or more and 40 μm or less. Here, the net having the minimum opening is the net when the number of nets used for the sieve is one, and the net having the smallest opening is the case where the number of nets used for the sieve is multiple. It is a net. When the mesh opening of the mesh having the minimum mesh opening is within the above range, the number of coarse particles A and coarse particles B in the toner can be easily controlled to the above-mentioned number of particles. Further, when the mesh opening of the mesh having the minimum mesh opening is at least the above lower limit value, clogging can be suppressed. The upper limit of the mesh opening of the mesh having the minimum mesh opening is preferably 38 μm or less.

In the preferable sieving step, the ratio (F1 / F2) of the flow rate F1 [m ³ / min] of the primary air to the flow rate F2 [m ³ / min] of the secondary air is 18 or more and 50 or less. .. When the ratio (F1 / F2) is within the above range, the number of coarse particles A and coarse particles B in the toner can be easily controlled to the above-mentioned number of particles. Further, when the ratio (F1 / F2) is at least the above lower limit value, the coarse particles B can be efficiently removed and clogging can be suppressed. When the ratio (F1 / F2) is not more than the upper limit value, the coarse particles A can be appropriately retained in the toner. Further, when the ratio (F1 / F2) is set to be equal to or less than the upper limit value, it is possible to suppress a decrease in the recovery rate of toner particles. The lower limit of the ratio (F1 / F2) is preferably 20 or more, more preferably 22 or more, and the upper limit of the ratio (F1 / F2) is preferably 48 or less, more preferably 46 or less.
The value of the ratio (F1 / F2) is rounded to an integer according to Rule B of JIS Z8401: 1999.
The blower air volume, which is the total of the flow rate F1 of the primary air and the flow rate F2 of the secondary air, is not particularly limited, and the ratio (F1 / F2) is within the above range according to the area of the sieve. It may be adjusted as appropriate.

As the net used as a sieve, a laminated wire mesh in which two or more wire meshes are laminated is preferable from the viewpoint of suppressing breakage and efficiently removing coarse particles, and two or more wire meshes having different mesh openings are laminated. Laminated wire mesh is more preferred. Further, as the laminated wire mesh, a laminated wire mesh in which two or more wire meshes are laminated by sintering is preferable.

In the laminated wire mesh, it is preferable that the wire mesh having the smallest opening is arranged on the supply side of the particles containing the colored resin particles, and the wire mesh is laminated in the order of the size of the opening.
Further, from the viewpoint of not reducing the opening rate as much as possible, it is preferable to use a laminated wire mesh in which the meridians of all the wire meshes constituting the laminated wire mesh and the latitude lines of all the wire meshes are substantially parallel to each other as shown in FIG. ..

The opening of the wire mesh of the laminated wire mesh may be as long as the opening of the wire mesh having the minimum opening is within the above-mentioned range, and the opening of the wire mesh other than the wire mesh having the minimum opening is not particularly limited. However, in the two wire meshes arbitrarily selected from all the wire meshes of the laminated wire mesh, the meshing ratio is preferably in the range of 2 to 30, more preferably in the range of 10 to 25. It is more preferably in the range of 12 to 20. Here, the opening ratio is the ratio of the opening of the wire mesh having a relatively large opening to the opening of the wire mesh having a relatively small opening among the two wire meshes. By setting the opening ratio within the above range, the reinforcing effect of the laminated wire mesh can be improved and clogging can be suppressed. The value of the opening ratio is a value rounded to an integer as in the case of F1 / F2.

The number of wire meshes included in the laminated wire mesh is not particularly limited, but is preferably 4 or less, more preferably 3 or less, and most preferably 2.

Further, it is preferable that all the openings of the wire mesh of the laminated wire mesh are in the range of 25 to 850 μm. When the mesh opening of the laminated wire mesh is at least the above lower limit value, damage and clogging of the wire mesh can be suppressed, while when it is at least the above upper limit value, the strength of the laminated wire mesh is improved. be able to.

The wire diameter of the wire of the net is not particularly limited, but the wire diameter of the wire of the wire net having the minimum opening is preferably 20 to 90 μm, and more preferably 25 to 80 μm.
In the laminated wire mesh, the ratio of the wire diameters of the two wire meshes arbitrarily selected from the wire meshes of the laminated wire mesh is preferably in the range of 1.1 to 26, and preferably in the range of 1.15 to 20. It is more preferable to have. Here, the ratio of the wire diameters of the two wire meshes is the ratio of the wire diameter of the wire mesh having a relatively large wire diameter to the wire diameter of the wire mesh having a relatively small wire diameter.
Further, it is preferable that all the wire diameters of the wire mesh included in the laminated wire mesh are in the range of 20 to 550 μm, and more preferably in the range of 25 to 525 μm.

In the above preferable sieving step, when the particles containing the colored resin particles are supplied to the sieve using an air flow, the solid-gas ratio of the particles to the air is set to 0.05 to 0.37 in terms of mass. Is preferable, 0.07 to 0.34 is more preferable, and 0.10 to 0.30 is further preferable. When the solid air ratio is at least the above lower limit value, a sufficient amount of particles can be supplied to the sieve, so that productivity is improved. When the solid air ratio is at least the above upper limit value, the particles are in the air flow. Since it can be uniformly dispersed in the air, clogging is suppressed and a decrease in recovery rate is suppressed.

In the present disclosure, the solid-gas ratio of particles to air in terms of mass is calculated by the following formula (i).

Equation (i)
Solid air ratio (kg / kg) = particle supply rate (kg / Hr) / air supply rate (kg / Hr)

In the formula (i), the air supply rate is obtained by the following formula (ii).

Equation (ii)
Air supply rate (kg / Hr) = blower air volume (m ³ / Hr) x air density (kg / m ³ )

In the present disclosure, the air density is calculated as 1.293 kg / m ³ which is the density under 1 atm at 0 ° C. in the formula (ii).

Further, in the sieving step, it is preferable to remove coarse particles so that the pressure difference before and after sieving is usually 3 kPa or less, preferably 2 kPa or less. By removing the coarse particles so that the pressure difference before and after the sieve is within the above range, clogging of the sieve can be suppressed.

In the present disclosure, in order to remove coarse particles or foreign matter having a circle equivalent diameter of 200 μm or more, a sieving step using a net having a larger opening than the net used in the above-mentioned preferable sieving step is further provided. You may. The sieving step for removing coarse particles or foreign matter having a circle equivalent diameter of 200 μm or more is not particularly limited, but is preferably performed after the external addition step.

In the present disclosure, the toner thus obtained may be used as a one-component developer, or may be further mixed and stirred with carrier particles and used as a two-component developer.

Hereinafter, the present disclosure will be described in more detail with reference to Examples and Comparative Examples, but the present disclosure is not limited to these Examples. In addition, parts and% are based on mass unless otherwise specified.

[Production Example 1: Production of Copolymer 1]
200 parts of toluene was put into the reaction vessel, the inside of the reaction vessel was sufficiently replaced with nitrogen while stirring the toluene, and then the temperature was raised to 90 ° C. After that, 96.2 parts of methyl methacrylate, 3.5 parts of ethyl acrylate, 0.4 part of acrylic acid, and t-butylperoxy-2-ethylhexanoate (manufactured by NOF CORPORATION, trade name: Perbutyl O) 2. Eight parts of the mixed solution was added dropwise into the reaction vessel over 2 hours. Further, the polymerization was completed by holding the mixture under reflux with toluene for 10 hours, and then the solvent was distilled off under reduced pressure. In this way, the copolymer 1 (Tg77.8 ° C., acid value 2.4 mgKOH / g, weight average molecular weight Mw12500) was obtained.
The weight average molecular weight Mw of the copolymer 1 was determined in terms of polystyrene by GPC. The sample for measurement was prepared by dissolving the polymer in tetrahydrofuran (THF) to a concentration of 2 mg / mL, performing ultrasonic treatment for 10 minutes, and then passing through a 0.45 μm membrane filter. The measurement conditions were temperature: 40 ° C., solvent: tetrahydrofuran, flow velocity: 1.0 mL / min, concentration: 0.2 wt%, sample injection amount: 100 μL, and the column was GPC TSKgel Multipole HXL-M manufactured by Tosoh Corporation. 30 cm x 2) was used. Further, the measurement was performed under the condition that the first-order correlation formula of Log (Mw) -elution time between weight average molecular weight Mw 1,000 and 300,000 was 0.98 or more.

[Example 1]
1. 1. Preparation of sieving machine A laminated wire mesh was prepared by sintering a first wire mesh having a mesh opening of 34 μm and a second wire mesh having a mesh opening of 617 μm in a state where the meridians and parallels were parallel to each other. .. In all the wire meshes used in each embodiment, the meridians and parallels are orthogonal to each other, and the meridians and parallels are arranged at equal intervals, and the intervals between the meridians and the parallels are the same. The opening of the wire mesh is square). The ratio of the opening of the second wire mesh to the opening of the first wire mesh was 18.
The laminated wire mesh was attached to a blow-through type sieve (trade name: High Bolter, model: NR-450S, manufactured by Toyo High-Tech Co., Ltd.) so that particles were supplied from the first wire mesh side.

2. 2. Preparation of Colored Resin Particles (1) Preparation of Polymerizable Monomer Composition for Core 77 parts of styrene and 23 parts of n-butyl acrylate as monovinyl monomer, carbon black as colorant (manufactured by Mitsubishi Chemical Co., Ltd., trade name: # 25B) 7 parts, divinylbenzene 0.6 parts as a crosslinkable polymerizable monomer, t-dodecyl mercaptan 1.2 parts as a molecular weight adjuster, polymethacrylic acid ester macromonomer as a macromonomer (manufactured by Toa Synthetic Chemical Industry Co., Ltd.) , Trade name: AA6, Tg = 94 ° C.) 0.3 part, and polar resin (polymer 1 obtained in Production Example 1) 1.0 part are wet pulverized using a media type wet pulverizer. The mixture was obtained. 1 part of a charge control resin (styrene acrylic resin containing a quaternary ammonium salt as a functional group and a copolymerization ratio of a monomer containing a functional group of a quaternary ammonium salt: 2% by mass) as a charge control agent in this mixture. 20 parts of behenyl stearate (number average molecular weight Mn: 592) was added and mixed as a mold release agent to obtain a polymerizable monomer composition for a core.

(2) Preparation of aqueous dispersion medium On the other hand, in an aqueous solution in which 7.4 parts of magnesium chloride (water-soluble polyvalent metal salt) is dissolved in 250 parts of ion-exchanged water at room temperature, 50 parts of ion-exchanged water is added. An aqueous solution in which 4.1 parts of sodium hydroxide (alkali metal hydroxide) was dissolved was gradually added under stirring to prepare a magnesium hydroxide colloid (water-insoluble inorganic hydroxide colloid) dispersion.

(3) Preparation of Polymerizable Monomer for Shell On the other hand, 2 parts of methyl methacrylate and 65 parts of ion-exchanged water are finely dispersed by an ultrasonic emulsifier to obtain an aqueous dispersion of the polymerizable monomer for shell. Prepared.

(4) Preparation of Suspension The polymerizable monomer composition for the core is added to the magnesium hydroxide colloidal dispersion and stirred, and t-butylperoxyisobutyrate (daily) is used as a polymerization initiator. 6 parts of oil company, trade name: perbutyl IB) was added. After that, using an in-line emulsion disperser (manufactured by Pacific Machinery & Engineering Co., Ltd., trade name: Milder), the peripheral speed of the rotor is 23.6 m / s and the rotation speed is 15,000 rpm, and the above formula (I) is used. A suspension in which droplets of the polymerizable monomer composition for a core were dispersed in an aqueous dispersion medium was prepared by performing a dispersion treatment while circulating until the number of circulations of the dispersion liquid calculated by ..

(5) Formation of Colored Resin Particles 1 part of sodium tetraborate decahydrate was added to the suspension prepared above. The suspension to which sodium tetraborate decahydrate was added was placed in a reactor equipped with a stirring blade, and the temperature was raised to 85 ° C. to carry out a polymerization reaction. After the polymerization conversion reaches almost 100%, the aqueous dispersion of the polymerizable monomer for shells prepared above and 2,2'-azobis (2-methyl-N- (2-methyl-N- (2-methyl-N-) as the polymerization initiator for shells. 2-Hydroxyethyl) -propionamide) (manufactured by Wako Junyaku Co., Ltd., trade name: VA-086, water-soluble) 0.3 part was added to the reactor. Further, after continuing the polymerization for 4 hours, the reaction was stopped by water cooling to obtain an aqueous dispersion of colored resin particles having a core-shell structure.

(6) Post-treatment step The aqueous dispersion of the colored resin particles was washed with dilute sulfuric acid (25 ° C. for 10 minutes) to bring the pH to 4.5 or less. Then, after separating the water by filtration, 200 parts of ion-exchanged water was newly added to form a reslurry, and washing, filtration, and dehydration were repeated several times at room temperature (25 ° C.) for water washing treatment. The obtained solid content was separated by filtration to obtain colored resin particles having a water content of 10%. The water content of the colored resin particles was determined by weight reduction when dried in an oven at 105 ° C. for 2 hours.

3. 3. First External Addition Step To 100 parts of the obtained colored resin particles, 0.2 parts of hydrophobic silica fine particles having a number average primary particle size of 7 nm treated with cyclic silazane as an external additive were added to form a conical shape. Using a mixer (manufactured by Hosokawa Micron Co., Ltd., trade name: Nauta Mixer), the mixture was mixed and stirred at 45 ° C. for 10 hours and dried.

4. Sieving step Using the blow-through type sieving machine, the blower air volume is 14 m ³ / min, the primary air flow rate F1 is 13.4 m ³ / min, and the secondary air flow rate F2 is 0.6 m ³ / min. The particles obtained by the first external addition step were supplied to the sieve by an air flow for 1 hour to sieve the particles.

5. Second external addition step The average number of mixed particles (colored resin particles 100 parts, hydrophobicized silica fine particles 0.2 part) obtained by the above sieving step treated with amino-modified silicone oil as an externalizing agent. Example 1 by adding 1 part of hydrophobic silica fine particles having a primary particle size of 35 nm, mixing and stirring using a high-speed stirrer (manufactured by Nippon Coke Industries, Ltd., trade name: FM mixer) to perform external addition treatment. A toner for developing an electrostatic charge image was prepared.

[Examples 2 to 6 and Comparative Examples 1 to 4]
In Example 1, as the first wire mesh and the second wire mesh used for the laminated wire mesh, the open wire mesh shown in Table 1 is used, and the flow rate F1 of the primary air and the flow rate F2 of the secondary air in the sieving step are shown in the table. Toners for developing electrostatic charge images of Examples 2 to 6 and Comparative Examples 1 to 4 were produced in the same manner as in Example 1 except that the changes were made according to 1.

[Comparative Example 5]
In Example 1, instead of the blow-through type sieving machine, a vibrating type sieving machine (a circular vibrating sieving machine manufactured by Kowa Kogyo Co., Ltd.) is used as the sieving machine, and the first wire mesh used for the laminated wire mesh and the first wire mesh. The static charge image developing toner of Comparative Example 5 was produced in the same manner as in Example 1 except that the wire mesh having the openings shown in Table 1 was used as the second wire mesh.

[Comparative Example 6]
1. 1. Preparation of sieving machine The same sieving machine as that used in Example 1 was used.

2. 2. Preparation of colored resin particles <Preparation of resin particle dispersion liquid>
320 parts of styrene, 80 parts of n-butyl acrylate, 9 parts of β-carboxyethyl acrylate, 1.5 parts of 1,10 decanediol diacrylate and 2.7 parts of dodecane thiol were mixed and dissolved. The obtained mixture was dissolved in 550 parts of ion-exchanged water containing 4 parts of anionic surfactant, further dispersed and emulsified in a stirring tank, and gradually stirred and mixed in 10 minutes to 6 parts of ammonium persulfate. 50 parts of ion-exchanged water in which the above was dissolved was added. Next, after sufficient nitrogen substitution in the system, the stirring tank jacket was heated until the temperature in the tank reached 70 ° C. while stirring the inside of the stirring tank, and the emulsion polymerization was continued for 5 hours to disperse the resin particles. Obtained liquid.

<Preparation of colorant particle dispersion>
90 parts of phthalocyanine pigment (PVFASTBLUE manufactured by Dainichi Seika Co., Ltd.), 10 parts of anionic surfactant (Neogen R manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and 240 parts of ion-exchanged water are mixed in a stirring tank, and the dispersion pressure is increased. A colorant particle dispersion was prepared by dispersion treatment using an ultimateizer HJP-2570 (manufactured by Sugino Machine Limited) set at 196 MPa.

<Preparation of mold release agent dispersion>
30 parts of paraffin wax, 2.5 parts of anionic surfactant, and 67.5 parts of ion-exchanged water were heated to 95 ° C., dispersed using a homogenizer, and then dispersed with a dynomill to disperse a release agent. Got

<Preparation of colored resin particles>
400 parts of ion-exchanged water, 240 parts of resin particle dispersion, 44 parts of colorant dispersion, 56 parts of release agent dispersion, 12 parts of inorganic fine particle dispersion (Snowtex OL, manufactured by Nissan Chemical Co., Ltd.) and inorganic fine particle dispersion ( 10 parts of Snowtex OS (manufactured by Nissan Chemical Co., Ltd.) were put into a stirring tank, and sufficiently mixed and dispersed with a homogenizer. To the obtained dispersion, a mixture of 0.5 part of a flocculant (polyaluminum chloride manufactured by Asada Chemical Co., Ltd.) and 100 parts of ion-exchanged water was added over 10 minutes while stirring the stirring tank, and after the addition was completed. The mixture was gently heated to 40 ° C., held for 30 minutes, and then heated to 49 ° C. After holding at 49 ° C. for 40 minutes, the temperature was further raised and held at 52 ° C. for 40 minutes.
Further, 65 parts of the resin particle dispersion liquid was slowly added to the dispersion liquid, the temperature was further raised, and the temperature was maintained at 53 ° C. for 1 hour.
Next, a 1 mol / liter aqueous sodium hydroxide solution was added so that the pH became 6.0, and then the mixture was gently heated to 85 ° C. and held for 60 minutes while continuing stirring. Then, the mixture was heated to 96 ° C., a 1 mol / liter aqueous nitric acid solution was added until the pH reached 5.0, and the mixture was kept for 5 hours.
Then, the obtained toner slurry was cooled to 40 ° C., the toner slurry was sieved with a mesh of 15 μm, and then filtered with a filter press (manufactured by Tokyo Engineering Co., Ltd.) to obtain colored resin particles.

For 100 parts of the obtained colored resin particles, 500 parts of ion-exchanged water is passed through the toner in the filter press device, and then 300 parts of ion-exchanged water is mixed with a 1 mol / liter aqueous nitrate solution until the pH reaches 3.0. The added acid washing water was passed through, and further 400 parts of ion-exchanged water was passed through, and the mixture was squeezed and dehydrated to obtain a wet toner.
This wet toner was crushed by Landelmill RM-1 (manufactured by Tokuju Kosakusho) to obtain a wet toner as a drying raw material.

Drying was carried out using a loss-in weight feeder (manufactured by Kuma Engineering Co., Ltd., type 602) as a wet toner feeder and a flash jet dryer (manufactured by Seishin Corporation) as an airflow dryer. A Henschel mixer (manufactured by Mitsui Mine) was used as the external additive mixing device. For 100 parts of toner, 1.5 parts of hydrophobic silica (volume average particle size 0.1 μm), 0.55 parts of cerium oxide (volume average particle size 0.7 μm), and zinc stearate (volume) are used as external additives. An average particle size of 7.69 μm) was mixed with 0.3 part to obtain toner particles.

3. 3. Sieving step Using the blow-through type sieving machine, the blower air volume is 14 m ³ / min, the primary air flow rate F1 is 12.8 m ³ / min, and the secondary air flow rate F2 is 1.2 m ³ / min. The obtained toner particles were supplied to the sieve by an air flow for 1 hour to sieve the particles, thereby producing the static charge image developing toner of Comparative Example 6.

[evaluation]
The toner for static charge image development obtained in each Example and each Comparative Example was measured or evaluated by the following method.

1. 1. A flow-type particle image measuring device (manufactured by Simex, trade name:) uses a dispersion liquid in which 10 g of toner is dispersed in 300 g of water containing a surfactant having an average circle equivalent diameter and an average circularity of 0.3%. A projected image of the particles in the sample liquid was photographed using FPIA-3000), and the diameter of a circle equal to the projected area of the particles was measured from the projected image to obtain the equivalent circle diameter of each toner particle. The circularity of each toner particle was obtained from the projected image by measuring the peripheral length of a circle equal to the projected area of the particles and the peripheral length of the particle projected image, and using the above formula 1. The arithmetic mean of the circle-equivalent diameters of each toner particle contained in the sample liquid was calculated and used as the average circle-equivalent diameter, and the arithmetic mean of the circularity was calculated and used as the average circularity.

2. 2. A toner dispersion liquid in which 10 g of toner was dispersed in 300 g of water containing a surfactant having a particle number of coarse particles of 0.3% in the toner was passed through a sieve having an opening of 25 μm. Then, the water containing the surfactant was further passed through the sieve, and the water was passed through the sieve until the water passing through the sieve had no toner color with the naked eye. Then, the coarse particles remaining on the sieve were recovered with water containing 0.3% of a surfactant to obtain a coarse particle dispersion, and the mass of the obtained dispersion was recorded. The particle size distribution of the coarse particle dispersion was measured using a flow-type particle image measuring device, and the number of coarse particles A having a circular equivalent diameter of 50 μm or more and less than 200 μm and a circularity of 0.20 or more and less than 0.97. The number of coarse particles B having a circular equivalent diameter of 50 μm or more and less than 200 μm and a circularity of 0.97 or more and 1.00 or less was measured. The number of coarse particles A contained in the coarse particle dispersion in the measurement cell NA (pieces), the number of particles _NB (pieces) of the coarse particles _B , the capacity C (g) of the measurement cell, and the entire coarse particle dispersion. From the mass _WD (g) and the mass _WT (g) of the toner used for the measurement, the number of coarse particles A contained in 1.0 g of the toner according to the above-mentioned calculation formulas (A) and (B). And the number of coarse particles B was determined.
Further, the number of coarse particles A having a circularity of 0.95 or more and less than 0.97 was determined by the same method.

3. 3. Recovery rate In each Example and each Comparative Example, after sieving, the weight A of the particles in the coarse particle recovery container and the weight B of the particles in the recovery container that passed through the sieve were weighed and calculated by the following formulas. The recovery rate was calculated.
Recovery rate (%) = {B / (A + B)} x 100

4. White streak evaluation under L / L environment or H / H environment Commercially available non-magnetic one-component development printer (printing speed: 20 sheets / minute) and toner to be evaluated are placed in a low temperature and low humidity (L / L) environment. It was left for 24 hours under a low temperature (temperature: 10 ° C., relative humidity: 20% RH) or in a high temperature and high humidity (H / H) environment (temperature: 32.5 ° C., relative humidity: 80% RH). After that, under the same environment, a printing test was performed at a printing density of 5%, and solid black printing (printing density 100%) was performed every 1,000 sheets to check for the presence or absence of white vertical streaks (white streaks). confirmed. The number of sheets (the number of white streaks generated) when white vertical streaks were first confirmed on the black solid image was counted, and a printing test was performed up to a maximum of 10,000 sheets.
If no white streaks occur in the printing test for up to 10,000 sheets, ">10000" is shown in Table 1.

5. Fog evaluation in H / H environment Under high temperature and high humidity (H / H) environment (temperature: 32.5 ° C, relative humidity: 80% RH), the same printing test as the above white streak evaluation was performed and 1,000. Following black solid printing (print density 100%) for each sheet, white solid printing (print density 0%) was performed. The printer was stopped in the middle of solid white printing, the toner in the non-image area on the developed photoconductor was attached to the adhesive tape, and the toner was attached to the printing paper. Next, the whiteness (B) of the printing paper to which the adhesive tape is attached is measured with a whiteness meter, and similarly, only the unused adhesive tape is attached to the printing paper, and the whiteness (A) is obtained. Was measured, and this difference in whiteness (BA) was used as the fog value. The number of sheets (the number of sheets in which fog was generated) when the fog value became 2.0 or more for the first time was counted, and a printing test was performed up to a maximum of 10,000 sheets.
If the fog value is less than 2.0 in the printing test for up to 10,000 sheets, it is indicated as ">10000" in Table 1.

[Discussion]
In the toner obtained in Comparative Example 1, the number of coarse particles A exceeded 20000 and the number of coarse particles B was 1000 or more in 1.0 g of the toner, so that the toner was in an L / L environment. White streaks occurred in the printing test. In the toner obtained in Comparative Example 2, the number of coarse particles A and coarse particles B in the toner was further larger than that in Comparative Example 1, so that white streaks were generated earlier in the printing test in the L / L environment. However, white streaks also occurred in the printing test under the H / H environment. In Comparative Example 1 and Comparative Example 2, since the mesh size of the mesh used in the sieving step was too large, the coarse particles A and the coarse particles B passed through in the sieving step, and the coarse particles A and the coarse particles remained in the toner. It is probable that the amount of B was large.
In Comparative Example 3, in the sieving step, as a result of supplying the particles to the sieve with an air flow in which the ratio (F1 / F2) of the flow rate F1 of the primary air to the flow rate of the secondary air is 8, the differential pressure suddenly increases. Due to the rise, it was stopped halfway.
Since the toners obtained in Comparative Examples 4 to 6 had less than 1000 coarse particles A in 1.0 g of the toner, fog occurred in the printing test in the H / H environment. In Comparative Example 4, in the sieving step, the particles are supplied to the sieve with an air flow in which the ratio (F1 / F2) of the flow rate F1 of the primary air to the flow rate of the secondary air is 139, and the ratio of F1 to F2 is As a result of reducing the chance that the coarse particles that did not pass through the sieve are supplied to the sieve again by the secondary air because they were too large, both the coarse particles A and the coarse particles B are difficult to pass through the sieve, and the coarse particles are contained in the toner. It is probable that A could not be retained appropriately. In Comparative Example 5, in the sieving step, the sieving step was performed using the vibration type sieving machine used in Example 1 of Patent Document 1 without using an air flow, so that the coarse particles A and the coarse particles B were separated. It is probable that all of them were difficult to pass through the sieve and the coarse particles A could not be appropriately left in the toner. In Comparative Example 6, the toner was produced under the same conditions as in Example 1 of Patent Document 2. That is, colored resin particles are produced by the emulsification aggregation method, and in the sieving step, the particles are supplied to the sieve with an air flow in which the ratio (F1 / F2) of the flow rate F1 of the primary air to the flow rate of the secondary air is 11. did. In the method for producing colored resin particles performed in Comparative Example 6, it is considered that the coarse particles A and the coarse particles B in the toner were both small because it was difficult to generate the coarse particles A and the coarse particles B.

On the other hand, in the toners obtained in Examples 1 to 6, the number of coarse particles A is 1000 or more and 20000 or less, and the number of coarse particles B is less than 1000 in 1.0 g of the toner. Therefore, no white streaks were generated in the above printing test under either the H / H environment or the L / L environment, and no fog was generated in the above printing test under the H / H environment. In Examples 1 to 6, in the sieving step, particles are supplied to the sieve using an air flow rate, and among the meshes used for the sieve, the mesh size of the mesh having the smallest mesh size is set to 25 μm or more and 40 μm or less, and air is used. The ratio (F1 / F2) of the flow rate F1 of the primary air to generate the flow and the flow rate F2 [m ³ / min] of the secondary air was set to 18 or more and 50 or less. As a result, the coarse particles B having a relatively high circularity did not pass through the sieve, and the coarse particles A having a relatively low circularity could pass through the sieve appropriately. It is considered that the coarse particles A could be appropriately left in the toner.

1 Ejector 2 Air blowout nozzle 3 Powder fluid suction nozzle 4 Powder granules 5 Air blowout direction 6 Powder fluid suction direction 7 Dispersed powder fluid travel direction 11 Feeder 12 Primary air intake mechanism 13 Sieving machine 14 Net 15 Coarse particle drop port 16 Secondary air intake mechanism 17 Coarse particle recovery container 18 Piping 19 Cyclone 20 Recovery container 21 Blower 22 Flow adjustment valve

Claims (4)

Colored resin particles containing a binder resin, a colorant and a mold release agent, and a toner for developing an electrostatic charge image containing an external additive.
When the toner is passed through a sieve having an opening of 25 μm by a wet method, among the coarse particles that do not pass through the sieve, the equivalent circle diameter measured by the flow type particle image measuring device is 50 μm or more and less than 200 μm and the circularity. The number of coarse particles A in which is 0.20 or more and less than 0.97 is 1000 or more and 20000 or less in 1.0 g of toner, and the equivalent circle diameter measured by the flow type particle image measuring device is 50 μm or more and 200 μm. A toner for static charge image development in which the number of coarse particles B having less than or less than 0.97 and having a circularity of 0.97 or more and 1.00 or less is less than 1000 in 1.0 g of the toner. The toner for static charge image development according to claim 1, wherein the average circularity is 0.98 or more and 1.00 or less. The method for producing a toner for static charge image development according to claim 1 or 2.
A step of preparing a suspension in which droplets of a polymerizable monomer composition containing at least a polymerizable monomer, a colorant and a mold release agent are dispersed in an aqueous dispersion medium.
A method for producing a toner for static charge image development, which comprises a step of forming colored resin particles by subjecting the suspension to a polymerization reaction in the presence of a polymerization initiator. Further having a step of removing a part of the coarse particles contained in the particles by supplying the particles containing the colored resin particles to the sieve using an air flow.
The sieve contains at least one mesh, and among the meshes used for the sieve, the mesh having the smallest mesh opening is 25 μm or more and 40 μm or less.
The air flow is generated by the primary air supplied together with the particles containing the colored resin particles and the secondary air supplied from the recovery port side of the coarse particles, and the flow rate of the primary air. The static charge image developing toner according to claim 3, wherein the ratio (F1 / F2) of F1 [m ³ / min] to the flow rate F2 [m ³ / min] of the secondary air is 18 or more and 50 or less. Manufacturing method.

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