JP2021012321A - Method for manufacturing toner particle - Google Patents

Abstract

To distribute, of binders, one with high molecules near a surface layer, improve maintainability, is excellent in fixability, and reduce a residual monomer.SOLUTION: A method for manufacturing a toner particle includes a preparation step of preparing a polymerizable monomer composition containing a polymerizable monomer and first and second polymerization initiators, a granulation step, and a polymerization step. The first and second polymerization initiators are soluble in the monomer. The 10-hour half-life temperature of the first polymerization initiator is 45.0 to 65.0°C. The same temperature of the second polymerization initiator is 70.0 to 115.0°C. In the preparation step, the content of the first polymerization initiator is 2.5 to 20.0 mol% based on the monomer. The polymerization step includes a second polymerization step of, when the remaining ratio of the second polymerization initiator is 50% or more, adding a third water-soluble polymerization initiator to perform further polymerization. In the second polymerization step, when the third polymerization initiator is added into an aqueous medium, the remaining amount of the second polymerization initiator is 20.0 mol% or more based on the addition amount of the third polymerization initiator.SELECTED DRAWING: None

Description

The present invention relates to a method for producing toner particles for developing an electrostatic charge image used for image formation by an electrophotographic method.

In recent years, quality requirements for image forming devices such as copiers and printers have been strict, and the performance required for toner has also become high. In particular, in full-color copiers or full-color printers, there is a strong demand for miniaturization, energy saving, and environmental friendliness, and further improvements in durability, low-temperature fixability, and reduction of residual monomers are required. The toner is also required to have better durability and low temperature fixability.
In response to this requirement, in a method of producing toner by polymerization, a toner having a core-shell structure is provided with good storage stability by setting the particle size, average circularity and hardness of the toner within an appropriate range. There is a method of obtaining a toner having high image quality and excellent durability by obtaining fixability (Patent Document 1).
Further, polymerization is carried out using two or more kinds of polymerization initiators including a specific polymerization initiator, and the obtained polymer has at least one peak or shoulder on each of the low molecular weight side and the high molecular weight side in the molecular weight distribution of the obtained polymer. There is a method of obtaining a toner having excellent fixability and durability (Patent Document 2).

JP-A-2007-171272 Patent No. 4557855

However, there are still some issues with residual monomers. Further, in a high temperature and high humidity environment and a low temperature and low humidity environment, there are still some problems regarding durability.
An object of the present invention is to use two types of polymerization initiators having a specific structure and physical properties in the polymerization step in an aqueous medium and a water-soluble initiator, so that among the toner binders, the polymer one is placed near the toner surface layer. It is an object of the present invention to provide a method for producing a toner particle which is distributed, has improved storage stability, has excellent fixability, and has a reduced residual monomer (polymerizable monomer) in the toner particle.

The present invention is a preparation step for preparing a polymerizable monomer composition containing a polymerizable monomer, a first polymerization initiator and a second polymerization initiator, the polymerizable monomer composition in an aqueous medium. A method for producing toner particles, which comprises a granulation step of forming particles of a substance and a polymerization step of polymerizing the polymerizable monomer contained in the particles of the polymerizable monomer composition.
The first polymerization initiator and the second polymerization initiator are polymerization initiators that are soluble in the polymerizable monomer.
The first polymerization initiator is a compound represented by the following formula (1).

（式（１）中、Ｒ⁷、Ｒ⁸およびＲ⁹は、それぞれ独立に、炭素数１以上５以下のアルキル基を示し、Ｒ¹⁰は、炭素数１以上６以下のアルキル基を示す。）
該第１の重合開始剤の１０時間半減期温度が、４５．０℃以上６５．０℃以下であり、
該第２の重合開始剤が、下記式（２）または（３）で示される化合物であり、

(In the formula (1), R ⁷ , R ⁸ and R ⁹ each independently represent an alkyl group having 1 or more and 5 or less carbon atoms, and R ¹⁰ represents an alkyl group having 1 or more and 6 or less carbon atoms.)
The 10-hour half-life temperature of the first polymerization initiator is 45.0 ° C. or higher and 65.0 ° C. or lower.
The second polymerization initiator is a compound represented by the following formula (2) or (3).

（式（２）中、Ｒ¹は、炭素数１以上８以下のアルキル基を示し、Ｒ²は、水素原子または炭素数１以上５以下のアルキル基を示し、Ｒ³は、水素原子または炭素数１以上７以下のアルキル基を示す。）

(In the formula (2), R ¹ represents an alkyl group having 1 or more and 8 or less carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms, and R ³ is a hydrogen atom or carbon. Indicates an alkyl group of number 1 or more and 7 or less.)

（式（３）中、Ｒ⁴は、炭素数１以上８以下のアルキル基を示し、Ｒ⁵は、水素原子または炭素数１以上５以下のアルキル基を示し、Ｒ⁶は、水素原子または炭素数１以上７以下のアルキル基を示す。）
該第２の重合開始剤の１０時間半減期温度が、７０．０℃以上１１５．０℃以下であり、
該調製工程において調製された該重合性単量体組成物中の該第１の重合開始剤の含有量が、該重合性単量体に対して２．５モル％以上２０．０モル％以下であり、
該重合工程が、該第１の重合開始剤および該第２の重合開始剤によって、該重合性単量体を重合させる第１の重合工程、および、該第１の重合工程において該第２の重合開始剤の残存率が５０％以上のときに、第３の重合開始剤を該水系媒体中に添加し、該重合性単量体をさらに重合させる第２の重合工程を有し、
該第３の重合開始剤が、水溶性の重合開始剤であり、
該第２の重合工程において該水系媒体中に該第３の重合開始剤を添加したときの該第２の重合開始剤の残存量が、該第３の重合開始剤の添加量に対して２０．０モル％以上であることを特徴とするトナー粒子の製造方法に関する。

(In the formula (3), R ⁴ represents an alkyl group having 1 to 8 carbon atoms, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ⁶ represents a hydrogen atom or carbon. Indicates an alkyl group of number 1 or more and 7 or less.)
The 10-hour half-life temperature of the second polymerization initiator is 70.0 ° C. or higher and 115.0 ° C. or lower.
The content of the first polymerization initiator in the polymerizable monomer composition prepared in the preparation step is 2.5 mol% or more and 20.0 mol% or less with respect to the polymerizable monomer. And
The polymerization step is a first polymerization step in which the polymerizable monomer is polymerized by the first polymerization initiator and the second polymerization initiator, and the second polymerization step in the first polymerization step. It has a second polymerization step in which a third polymerization initiator is added to the aqueous medium to further polymerize the polymerizable monomer when the residual ratio of the polymerization initiator is 50% or more.
The third polymerization initiator is a water-soluble polymerization initiator.
When the third polymerization initiator is added to the aqueous medium in the second polymerization step, the residual amount of the second polymerization initiator is 20 with respect to the addition amount of the third polymerization initiator. The present invention relates to a method for producing toner particles, which comprises 0.0 mol% or more.

According to the present invention, it is possible to provide toner particles having excellent fixability and storage stability and reduced residual monomers.

Hereinafter, the present invention will be described in detail.

The present invention is a preparation step for preparing a polymerizable monomer composition containing a polymerizable monomer, a first polymerization initiator and a second polymerization initiator, the polymerizable monomer composition in an aqueous medium. A method for producing toner particles, which comprises a granulation step of forming particles of a substance and a polymerization step of polymerizing the polymerizable monomer contained in the particles of the polymerizable monomer composition, and has the following constitution. The effect of the present invention can be obtained by satisfying the above.
i) The first polymerization initiator and the second polymerization initiator are polymerization initiators that are soluble in the polymerizable monomer.
ii) The first polymerization initiator is a compound represented by the following formula (1).

（式（１）中、Ｒ⁷、Ｒ⁸およびＲ⁹は、それぞれ独立に、炭素数１以上５以下のアルキル基を示し、Ｒ¹⁰は、炭素数１以上６以下のアルキル基を示す。）

(In the formula (1), R ⁷ , R ⁸ and R ⁹ each independently represent an alkyl group having 1 or more and 5 or less carbon atoms, and R ¹⁰ represents an alkyl group having 1 or more and 6 or less carbon atoms.)

The 10-hour half-life temperature of the first polymerization initiator is 45.0 ° C. or higher and 65.0 ° C. or lower.
iii) The second polymerization initiator is a compound represented by the following formula (2) or (3).

（式（２）中、Ｒ¹は、炭素数１以上８以下のアルキル基を示し、Ｒ²は、水素原子または炭素数１以上５以下のアルキル基を示し、Ｒ³は、水素原子または炭素数１以上７以下のアルキル基を示す。）

(In the formula (2), R ¹ represents an alkyl group having 1 or more and 8 or less carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms, and R ³ is a hydrogen atom or carbon. Indicates an alkyl group of number 1 or more and 7 or less.)

（式（３）中、Ｒ⁴は、炭素数１以上８以下のアルキル基を示し、Ｒ⁵は、水素原子または炭素数１以上５以下のアルキル基を示し、Ｒ⁶は、水素原子または炭素数１以上７以下のアルキル基を示す。）

(In the formula (3), R ⁴ represents an alkyl group having 1 to 8 carbon atoms, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ⁶ represents a hydrogen atom or carbon. Indicates an alkyl group of number 1 or more and 7 or less.)

The 10-hour half-life temperature of the second polymerization initiator is 70.0 ° C. or higher and 115.0 ° C. or lower.
iv) The content of the first polymerization initiator in the polymerizable monomer composition prepared in the preparation step is 2.5 mol% or more and 20.0 mol% with respect to the polymerizable monomer. % Or less
v) In the first polymerization step in which the polymerizable monomer is polymerized by the first polymerization initiator and the second polymerization initiator, and in the first polymerization step. It has a second polymerization step in which a third polymerization initiator is added to the aqueous medium to further polymerize the polymerizable monomer when the residual ratio of the polymerization initiator of 2 is 50% or more.
vi) The third polymerization initiator is a water-soluble polymerization initiator.
vii) The residual amount of the second polymerization initiator when the third polymerization initiator is added to the aqueous medium in the second polymerization step is based on the amount of the third polymerization initiator added. Must be 20.0 mol% or more.

The reason why the effect of the present invention is exhibited is not always clear, but the present inventors consider it as follows.

The polymerization initiator has hydrophilicity and hydrophobicity, respectively, depending on its structure. The polymerization initiator having the first structure will have hydrophobic properties as compared with the second polymerization initiator having the structure of the formula (2) or the formula (3).

When toner particles are produced by granulating and polymerizing in an aqueous medium, a more hydrophilic substance is distributed on the surface of the toner particles. At that time, since the first polymerization initiator has a lower half-life temperature of 10 hours than the second polymerization initiator, the binder resin composed of the polymerizable monomer produced by the polymerization initiator having the structure of the formula (1). The molecular weight of is smaller than the molecular weight of the binder resin produced by the polymerization initiator having the structure of the formula (2) or the formula (3). When the residual ratio of the polymerization initiator of the formula (2) or the formula (3) is 50% or more in the first polymerization step, the third polymerization initiator, which is a water-soluble polymerization initiator, is contained in the aqueous medium. Add to.

Since the third polymerization initiator is a water-soluble initiator, it has hydrophilic properties as compared with the second polymerization initiator. Since it has more hydrophilic properties than the second polymerization initiator, the third polymerization initiator is distributed on the surface of the toner particle precursor as compared with the second polymerization initiator.
By adding the third polymerization initiator when the residual ratio of the second polymerization initiator is 50% or more, both the second polymerization initiator and the third polymerization initiator act in the vicinity of the surface of the toner particles. .. A binder resin formed in the vicinity of the surface of the toner particle precursor with respect to a portion where the second polymerization initiator acts selectively by the action of the second polymerization initiator and the third polymerization initiator. The molecular weight of is high.

Therefore, in the case of the toner particle manufacturing method of the present invention, toner particles in which the binder resin having a large molecular weight is distributed on the surface layer side of the toner particles and the binder resin having a small molecular weight is distributed on the center side of the toner particles can be obtained.

Further, when the polymerizable monomer is polymerized using a polymerizable monomer having a low half-life temperature of 10 hours, the polymerization initiator is cleaved from the initial stage of the polymerization reaction to generate radicals to carry out the polymerization reaction. Therefore, in the latter stage of the polymerization reaction, most of the polymerization initiator is consumed, so that the decrease of the polymerizable monomer is slowed down. On the other hand, in the present invention, since the polymerization initiator having a high half-life temperature of 10 hours is used in combination, the polymerization initiator remains even in the latter stage of the polymerization step and the subsequent distillation step, so that the polymerizable monomer is polymerized. In the polymerization step or the distillation step, it is possible to obtain toner particles in which the residual monomer is further reduced.

Furthermore, if only a polymerization initiator having a high 10-hour half-life temperature is used, the resulting binder resin will have a high molecular weight, and the fixability of the toner particles will tend to deteriorate, but a polymerization initiator having a low 10-hour half-life temperature will be used. Since it is used in combination, toner particles having good fixability can be obtained.

If the 10-hour half-life temperature of the first polymerization initiator is less than 45.0 ° C., the difference from the second polymerization initiator is too large, and it becomes difficult to adjust the molecular weight of the binder resin and the residual monomer. When the temperature exceeds 65.0 ° C., the difference from the polymerization initiator having the second structure is small, and the molecular weight of the binder resin distributed on the surface layer of the toner particles is not sufficiently large, resulting in insufficient heat resistance.

The effect of the present invention cannot be obtained by using either of the first polymerization initiator and the second polymerization initiator used in the present invention as the polymerization initiator. If only one of them is used, the binder resin produced will be in the same homogeneous state on both the surface layer side and the center side of the toner particles, so that it is difficult to achieve both fixability and storage stability.

When the 10-hour half-life temperature of the second polymerization initiator is less than 70.0 ° C., the difference from the first polymerization initiator is small, so that the molecular weight of the binder resin distributed on the surface layer of the toner particles is not sufficiently large. Therefore, the heat resistance becomes insufficient. In addition, the effect of reducing residual monomers is also reduced.

If the 10-hour half-life temperature of the second polymerization initiator exceeds 115.0 ° C., the difference between the first 10-hour half-life temperature and the polymerization initiator is too large, so that the molecular weight of the binder resin and the residual monomer Adjustment becomes difficult. Specifically, if the optimum conditions are set for the first initiator, the probability that the second polymerization initiator will generate radicals due to the polymerization reaction is low, and the polymerization reaction itself is difficult to proceed, so that the efficiency of reducing residual monomers is improved. On the contrary, the effect of the present invention cannot be obtained because the molecules of the binder resin which are lowered and distributed on the surface layer side of the toner cannot obtain a sufficient molecular weight. In the opposite case, it is difficult to control the molecular weight of the first initiator, and it is difficult to achieve both fixability and maintainability. In addition, since the first initiator is cleaved too quickly, it becomes difficult for the polymerization to proceed after the middle stage of the polymerization reaction, and similarly, the efficiency of reducing residual monomers is rather lowered. Further, since the amount of residual monomer is large, the toner particles are plasticized and easily aggregated.

When the residual ratio of the second polymerization initiator is 50% or more, the third polymerization initiator is added into the aqueous medium. When the residual ratio of the second polymerization initiator is less than 50%, there are few unreacted polymerizable monomers, and the third polymerization initiator does not contribute to the polymerization of the binder resin near the surface of the toner particles. , Improvement of storage stability cannot be expected.

As the structure of the first polymerization initiator and the second polymerization initiator, the first polymerization initiator has the structure of the formula (1), and the second polymerization initiator is the formula (2) or the formula. It has the structure of (3).

（式（１）中、Ｒ⁷、Ｒ⁸およびＲ⁹は、それぞれ独立に、炭素数１以上５以下のアルキル基を示し、Ｒ¹⁰は、炭素数１以上６以下のアルキル基を示す。）

(In the formula (1), R ⁷ , R ⁸ and R ⁹ each independently represent an alkyl group having 1 or more and 5 or less carbon atoms, and R ¹⁰ represents an alkyl group having 1 or more and 6 or less carbon atoms.)

（式（２）中、Ｒ¹は、炭素数１以上８以下のアルキル基を示し、Ｒ²は、水素原子または炭素数１以上５以下のアルキル基を示し、Ｒ³は、水素原子または炭素数１以上７以下のアルキル基を示す。）

(In the formula (2), R ¹ represents an alkyl group having 1 or more and 8 or less carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms, and R ³ is a hydrogen atom or carbon. Indicates an alkyl group of number 1 or more and 7 or less.)

（式（３）中、Ｒ⁴は、炭素数１以上８以下のアルキル基を示し、Ｒ⁵は、水素原子または炭素数１以上５以下のアルキル基を示し、Ｒ⁶は、水素原子または炭素数１以上７以下のアルキル基を示す。）

(In the formula (3), R ⁴ represents an alkyl group having 1 to 8 carbon atoms, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ⁶ represents a hydrogen atom or carbon. Indicates an alkyl group of number 1 or more and 7 or less.)

This is because the hydrophilicity and hydrophobicity of the two types of polymerization initiator residues, which are the causes of exhibiting the effects of the present invention, are better balanced. That is, of the two types of polymerization initiators that cause the effects of the present invention to be exhibited, the first polymerization initiator has one more oxygen atom in the polymerization initiator residue, so that the hydrophilicity is stronger and the surface of the toner particles is higher. This is because the high molecular weight binder resin is distributed on the side, and the action and effect of the present invention are strongly exhibited.

Examples of the compounds represented by the above formulas (1) to (3) include the following.

<Compound represented by formula (1)>
-T-hexyl peroxypivalate (perhexyl PV manufactured by NOF CORPORATION; 10-hour half-life temperature 53.2 ° C)
R ⁷ = CH ₃ −CH ₂ −CH ₂ −, R ⁸ = CH ₃ −, R ⁹ = CH ₃ −, R ¹⁰ = CH ₃ −
-T-Butyl peroxyneodecanoate (Perbutyl ND NOF CORPORATION; 10-hour half-life temperature 46.4 ° C)
R ⁷ = CH ₃ −, R ⁸ = CH ₃ −, R ⁹ = CH ₃ −, R ¹⁰ = C ₆ H ₁₃ −
-T-Butyl peroxypivalate (Perbutyl PV manufactured by NOF CORPORATION; 10-hour half-life temperature 54.6 ° C)
R ⁷ = CH ₃ −, R ⁸ = CH ₃ −, R ⁹ = CH ₃ −, R ¹⁰ = CH ₃ −

<Compound represented by formula (2)>
-T-Butyl peroxyisobutyrate (Luperox 80 manufactured by Arkema Yoshitomi Co., Ltd .; 10-hour half-life temperature 75 ° C)
R ¹ = (CH ₃ ) ₃ C −, R ² = CH ₃ −, R ³ = CH ₃ −
T-Amil peroxyisobutyrate (manufactured by Luperox 580 Arkema Yoshitomi Co., Ltd .; 10-hour half-life temperature 73 ° C)
R ¹ = C ₂ H ₅ − (CH ₃ ) ₂ C −, R ² = CH ₃ −, R ³ = CH ₃ −
-T-Butyl peroxy-2-ethylhexanoate (Perbutyl O manufactured by NOF CORPORATION; 10-hour half-life temperature 72.1 ° C)
R ¹ = (CH ₃ ) ₃ C −, R ² = CH ₃ CH ₂ −, R ³ = CH ₃ (CH ₂ ) ₃ −
T-Butyl peroxyacetate (Perbutyl A manufactured by NOF CORPORATION; 10-hour half-life temperature 101.9 ° C)
R ¹ = (CH ₃ ) ₃ C-, R ² = H, R ³ = H

<Compound represented by formula (3)>
-T-Butyl peroxyisopropyl monocarbonate (Perbutyl I manufactured by NOF CORPORATION; 10-hour half-life temperature 98.7 ° C)
R ⁴ = (CH ₃ ) ₃ C −, R ⁵ = CH ₃ −, R ⁶ = CH ₃ −

If the amount of the first polymerization initiator added is less than 2.5 mol% with respect to the polymerizable monomer, the polymerization initiator is almost consumed at an early stage of the reaction, and the second initiator remains. Even if it is, the residual monomer cannot be completely reduced, and the toner particles are likely to aggregate due to the plasticizing effect of the residual monomer. When the amount of the first polymerization initiator added is more than 20.0 mol%, a large amount of oligomers are produced in the binder resin produced by the polymerization, so that the heat resistance is weak and the resin tends to aggregate.

A water-soluble initiator is used as the third polymerization initiator. Even if the oil-soluble initiator is added from the advanced stage of the polymerization step, the oil-soluble initiator cannot act on the polymerizable monomer and does not contribute to increasing the molecular weight of the toner particle surface. As the third polymerization initiator, potassium persulfate, ammonium persulfate, 2,2'-azobis (N, N'-dimethyleneisobutyroamidine) hydrochloride, 2,2'-azobis (2-aminodinopropane) ) Hydrochloride, azobis (isobutylamidine) hydrochloride, sodium 2,2'-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.

If the residual amount of the second polymerization initiator is less than 20.0 mol% with respect to the residual amount of the third polymerization initiator when the third polymerization initiator is added, the unreacted polymerizable unit amount Since the number of bodies is small, the third polymerization initiator does not contribute to the polymerization of the binder resin near the surface of the toner particles, and improvement in storage stability cannot be expected.

It is desirable that the amount of the first polymerization initiator added is larger than that of the second polymerization initiator. This is because the binding resin of the obtained toner particles contains an appropriate ratio of a high molecular weight component and a low molecular weight component, so that both the fixability and the heat resistance of the toner particles are improved. Further, it is desirable that the amount of the second polymerization initiator added is 5.0 mol% or more and 60.0 mol% or less with respect to the amount of the first polymerization initiator added. This is because it is desirable from the viewpoint of achieving both fixability and durability while reducing residual monomers. That is, the presence of the high molecular weight binder resin derived from the second polymerization initiator on the surface layer side of the toner particles improves the durability, and the ratio is appropriate so that the fixability is not impaired.

It is desirable that the amount of the second polymerization initiator added is larger than that of the third polymerization initiator. This is because when the third polymerization initiator acts on the toner surface, it acts on the toner surface while leaving a region in which the second polymerization initiator selectively acts.

The amount of the third polymerization initiator added is preferably 5.0 mol% or more and 90.0 mol% or less with respect to the amount of the second polymerization initiator added. This is because it is desirable from the viewpoint of achieving both fixability and durability while reducing residual monomers. That is, the presence of the high molecular weight binder resin derived from the third polymerization initiator on the surface layer side of the toner particles improves the durability, and the ratio is appropriate so that the fixability is not impaired.

It is preferable to raise the polymerization temperature in the middle of the first or second polymerization step. This is because the temperature suitable for the decomposition of the first polymerization initiator is higher than the temperature suitable for the decomposition of the second polymerization initiator because of the 10-hour half-life temperature, and the temperature is higher for the decomposition of the second polymerization initiator. This is because it takes time. It is preferable to raise the polymerization temperature during the first or second polymerization step to a temperature at which the second polymerization initiator decomposes at an appropriate rate.

It is desirable that the polymerizable monomer composition contains a crystalline material. As the crystalline substance that can be used in the present invention, known substances such as wax, crystalline polyester, and a mold release agent can be used. This is desirable because it is excellent in fixability.

In the case of the toner of the present invention, since the high molecular weight component of the binder resin is distributed on the side near the surface of the toner particles, the crystalline substance is difficult to be compatible with the vicinity of the surface of the toner particles and is difficult to be distributed. Therefore, it is desirable because the crystallinity improves the fixability, and the exposure to the surface of the toner particles is suppressed, so that the durability can be compatible.

The melting point Tm of the crystalline substance used in the present invention is preferably 50 ° C. or higher and 90 ° C. or lower. A more preferable range is 60 ° C. or higher and 85 ° C. or lower. When the melting point Tm of the crystalline substance is 50 ° C. or higher and 90 ° C. or lower, it is desirable from the viewpoint of achieving both fixability and storage stability.

The toner of the present invention may contain wax as a crystalline substance. In that case, at least one of the waxes preferably has a melting point (temperature corresponding to the maximum endothermic peak of the DSC endothermic curve in the temperature range of 20 ° C. or higher and 200 ° C. or lower) of 30 ° C. or higher and 120 ° C. or lower, preferably 50 ° C. or higher. More preferably, it is 90 ° C. or lower. Further, it is preferably a wax that is solid at room temperature, and a solid wax having a melting point of 50 ° C. or higher and 90 ° C. or lower is particularly preferable from the viewpoint of toner blocking resistance, multi-sheet durability, low temperature fixability, and offset resistance.

Examples of the wax include paramethylene wax, polyolefin wax, microcrystallin wax, polymethylene wax such as Fishertropsh wax, petroleum wax such as amide wax and petrolatum and its derivatives, Montan wax and its derivatives, carnauba wax and candelilla wax. Use known waxes such as natural waxes and their derivatives, hardened castor oil and its derivatives, vegetable waxes, animal waxes, higher fatty acids, long chain alcohols, ester waxes, ketone waxes and their graft compounds, block compounds and other derivatives. Is possible. These can be used alone or in combination.

The content of wax in the toner of the present invention is preferably 3 parts by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 20 parts by mass or less, and 4 parts by mass or more and 15 parts by mass with respect to 100 parts by mass of the binder resin. It is more preferably parts by mass or less. If the amount of wax added is not less than the lower limit value, the offset prevention effect is not lowered, and if it is less than the upper limit value, the blocking resistance effect is not lowered and the offset resistance effect is less likely to be adversely affected. Toner drum fusion and toner Development sleeve is unlikely to cause fusion.

When a hydrocarbon wax is used as the wax used in the present invention, it is more excellent in blocking resistance and offset resistance, and it is difficult for the toner to be fused to the toner layer regulating member or the toner carrier.

When a hydrocarbon wax is used as the wax and the toner particles also contain a crystalline polyester resin produced of an aliphatic diol and an aliphatic dicarboxylic acid, the interaction between the crystalline polyester and the wax causes the toner particles to interact with each other. Since crystallization is easily promoted, wax and crystalline polyester resin are less likely to be compatible with the binder resin on the surface layer side of the toner particles, and toner particles are less likely to aggregate during the polymerization process, which is desirable.

When it is necessary to extract the wax from the toner in order to obtain the above physical characteristics, the extraction method is not particularly limited, and any method can be used. For example, a predetermined amount of toner is soxhlet-extracted with toluene, the solvent is removed from the obtained toluene-soluble component, and then a chloroform-insoluble component is obtained. After that, identification analysis is performed by the IR method or the like.

In addition, regarding quantification, quantitative analysis is performed by DSC or the like. In the present invention, measurement is performed using DSC-2920 manufactured by TA Instruments Japan.

The intersection of the line at the midpoint of the baseline before and after the specific heat change at the time of measurement and the differential thermal curve is defined as the glass transition point. Further, the maximum endothermic peak temperature of the wax component is obtained from the obtained DSC curve at the time of temperature rise.

It is more desirable that the polymerizable monomer composition contains a crystalline polyester resin. It is desirable to contain a crystalline polyester resin because it has excellent fixability. However, when the polymerization reaction is carried out at a temperature equal to or higher than the melting point of the crystalline polyester resin in the polymerization step, the toner particles are more likely to aggregate in the polymerization step due to the plastic effect of the crystalline polyester resin. On the other hand, by using the first polymerization initiator and the second polymerization initiator used in the present invention, the high molecular weight binder resin is distributed on the surface layer side of the toner particles, so that the heat resistance is improved. Therefore, the toner particles are desirable because they suppress aggregation and utilize the effect of low temperature fixability of the crystalline polyester resin. At that time, since the high molecular weight binder resin derived from the first polymerization initiator has lower compatibility with the crystalline polyester resin, the crystalline polyester resin is compatible with the surface layer side of the toner particles. Since it is hard to exist, it is hard to be plasticized, and the heat resistance on the surface layer side of the toner particles can be maintained firmly, so that the toner particles are hard to aggregate, which is more desirable. A crystalline polyester resin has a larger molecular weight than a wax or a mold release agent, and is desirable because its effect is even greater.

The crystalline polyester resin can be obtained by reacting a divalent or higher valent carboxylic acid with a diol. Among them, polyester containing an aliphatic diol and an aliphatic dicarboxylic acid as main components is preferable because of its high crystallinity. As the crystalline polyester, only one kind may be used, or a plurality of kinds may be used in combination. Further, the toner may contain an amorphous polyester in addition to the crystalline polyester.

In the present invention, the crystalline polyester refers to a polyester having an endothermic peak at the time of temperature rise and a heat generation peak at the time of temperature decrease in differential scanning calorimetry (DSC), and the measurement is performed according to "ASTM D 3417-99".

(Pigment)
The toner of the present invention contains a pigment as a colorant. As the pigment used for the cyan-based colorant, a copper phthalocyanine compound and its derivative, an anthraquinone compound, and a basic dye lake compound can be used. Specifically, the following can be mentioned. C. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3 and C.I. I. Pigment Blue 15: 4.

As the pigment used for the magenta colorant, a condensed azo compound, a diketopyrrolopyrrole compound, anthraquinone, a quinacridone compound, a basic dye lake compound, a naphthol compound, a benzimidazolone compound, a thioindigo compound and a perylene compound can be used. Specifically, the following can be mentioned. C. I. Pigment Violet 19, C.I. I. Pigment Red 31, C.I. I. Pigment Red 32, C.I. I. Pigment Red 122, C.I. I. Pigment Red 150, C.I. I. Pigment Red 254, C.I. I. Pigment Red 264 and C.I. I. Pigment Red 269.

As the pigment used for the yellow colorant, a condensed azo compound, an isoindolinone compound, an anthraquinone compound, an azo metal complex, a methine compound and an allylamide compound can be used. Specifically, the following can be mentioned. C. I. Pigment Yellow 74, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 120, C.I. I. Pigment Yellow 139, C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 180 and C.I. I. Pigment Yellow 185.

As the black colorant, carbon black, a magnetic material, and those toned to black using the above-mentioned yellow, magenta, and cyan colorants can be used.

The pigment is carbon black, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Red 122, C.I. I. Pigment Red 150, C.I. I. Pigment Red 32, C.I. I. Pigment Red 269, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 180 and C.I. I. Pigment Yellow 185 is desirable because the effect of the present invention is high. Particularly desirable is carbon black, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Red 122. In the case of carbon black, it is preferable that the pH is 6 or more and the oil absorption (DBP) is 30 (cc / 100 g) or more and 120 (cc / 100 g) or less. This is because the polymerization initiator used in the present invention is less likely to inhibit the reaction.

The amount of these pigments added is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

(Other additives)
In the toner of the present invention, various known inorganic and organic additives can be used for the purpose of imparting various properties as long as the effects of the present invention are not impaired. The additive used preferably has a particle size of 3/10 or less of the weight average diameter of the toner particles from the viewpoint of durability when added to the toner. The particle size of this additive means the average particle size obtained by observing the surface of the toner particles with a scanning electron microscope.

The content of these additives is preferably 0.01 parts by mass or more and 5 parts by mass or less, and more preferably 0.02 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the toner.

These additives may be used alone or in combination of two or more.

Moreover, these additives may be hydrophobized. As a method of hydrophobization treatment, various coupling agents such as a silane coupling agent or a titanium coupling agent can be used, but it is preferable to increase the degree of hydrophobization with silicone oil. This is because it is possible to suppress the adsorption of water of the inorganic fine powder under high humidity, and further, it is possible to suppress the contamination of the regulating member and the charging member, so that a high-quality image can be obtained.

The weight average particle size (D4) of the toner is preferably 4.0 μm or more and 12.0 μm or less, and more preferably 4.0 μm or more and 9.0 μm or less. This is because if the weight average particle size is less than 4.0 μm, the specific surface area of the toner is large, so problems are likely to occur in durability and heat resistance during long-term use. If the weight average particle size exceeds 12.0 μm, the toner It is not desirable because it is inferior in terms of coloring power and image resolution.

[Polymerizable monomer]
As the polymerizable monomer used in the present invention, a vinyl-based polymerizable monomer capable of radical polymerization may be used in addition to styrene. As the vinyl-based polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used. Examples of the monofunctional polymerizable monomer include styrene; α-methylstyrene, β-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p. Styrene derivatives such as −phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2 Acrylic polymerizable such as -ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate. Monomer; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, Methacrylic polymerizable monomers such as n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid ester; vinyl acetate, vinyl propionate, vinyl butyrate, benzo Vinyl esters such as vinyl acid acid and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

Examples of the polyfunctional polymerizable monomer include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and tripropylene glycol. Diacrylate, polypropylene glycol diacrylate, 2,2'-bis (4- (acryloxy diethoxy) phenyl) propane, trimethylpropan triacrylate, tetramethylolmethanetetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis ( 4- (methacryloxy diethoxy) phenyl) propane, 2,2'-bis (4- (methacryloxy polyethoxy) phenyl) propane, trimethyl propane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalin, divinyl ether, etc. Can be mentioned.

In the present invention, the above-mentioned monofunctional polymerizable monomer is used alone or in combination of two or more, or the above-mentioned monofunctional polymerizable monomer and the polyfunctional polymerizable monomer are used in combination. To do.

Polymerizable monomers used in addition to styrene include styrene derivatives, acrylic acid ester-based polymerizable monomers such as n-butyl acrylate and 2-ethylhexyl acrylate, or methacrylic acid esters such as n-butyl methacrylate and 2-ethylhexyl methacrylate. Polymerizable monomers are desirable. This is because the binder resin obtained by polymerizing the polymerizable monomer is excellent in strength and flexibility.

(Production method)
Suspension polymerization is used as the method for producing the toner of the present invention, but the toner can be directly produced by the following production method. A polar resin such as polyester resin, a mold release agent, a colorant, a cross-linking agent, and other additives are added to the polymerizable monomer, and the mixture is uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, etc. to obtain a dispersion stabilizer. Disperse the mixture in the aqueous medium to be provided with a normal stirrer, a homomixer, a homogenizer, or the like. It has an adjustment step of adding a first polymerization initiator and a second polymerization initiator to the polymerizable monomer to prepare a polymerizable monomer composition. The stirring speed and time are adjusted so that the droplets of the polymerizable monomer composition have a desired toner size, and the particles are granulated to form particles of the polymerizable monomer composition. After that, the stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The first polymerization step is advanced by the first polymerization initiator and the second polymerization initiator. The polymerization temperature is set to 40 ° C. or higher, usually 50 to 120 ° C., for polymerization. When the polymerization temperature is 95 ° C. or higher, the container for which the polymerization reaction is carried out may be pressurized to suppress evaporation of the aqueous medium. The first polymerization temperature is preferably 0 to 30 ° C. higher than the 10-hour half-life temperature of the first polymerization initiator. When the residual ratio of the second polymerization initiator in the first polymerization step is 50% or more, the third polymerization initiator is added to the aqueous medium to perform the second polymerization step. A water-soluble polymerization initiator is used as the third polymerization initiator. When the third polymerization initiator is added, the residual amount of the second polymerization initiator is 20 mol% or more with respect to the addition amount of the third polymerization initiator.

In the second polymerization step, the temperature may be raised in the latter half of the polymerization reaction, or the pH may be changed if necessary. Further, the reaction temperature may be raised in the latter half of the reaction in order to remove unreacted polymerizable monomers, by-products and the like that cause an odor at the time of fixing. After completion of the reaction, the produced toner particle precursor dispersion liquid is obtained. Next, the toner particle precursor dispersion liquid is collected by cooling, washing, and filtering, and dried.

<Calculation method of the second polymerization initiator residual rate>
The residual rate of the second polymerization initiator was calculated by the following procedure. The 1-minute half-life temperature, 1-hour half-life temperature, and 10-hour half-life temperature of the polymerization initiator used were obtained. Each of the obtained half-life temperatures was graphed in a scatter plot using Microsoft Excel 2016 (16.0.4639.1000) 32-bit. A power approximation was selected from the created graph as an approximation curve option, and an approximation curve was obtained. The formula of the approximate curve was displayed and the formula for calculating the half-life was obtained. The temperature in the first polymerization step was substituted into the formula for calculating the half-life, and the residual rate of the second polymerization initiator was obtained.

<Method for quantifying residual monomers in toner particles>
The quantification of the residual monomer such as the residual styrene monomer in the toner is measured by gas chromatography (GC) as follows.

Weigh about 500 mg of toner and put it in a sample bottle. Approximately 10 g of precisely weighed acetone is added, the lid is closed, and the mixture is mixed well. A desktop ultrasonic cleaner with an oscillation frequency of 42 kHz and an electrical output of 125 W (for example, trade name "B2510J-MTH", manufactured by Branson). ) Is irradiated with ultrasonic waves for 30 minutes. Then, filtration is performed using a solvent-resistant membrane filter "Mysholidisk" (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm, and 2 μl of the filtrate is analyzed by gas chromatography. Then, the residual amount of the residual monomer is calculated from the calibration curve prepared in advance using various monomers such as styrene.

The measuring device and measuring conditions are as follows.
GC: HP 6890GC
Column: HP INNOWax (200 μm x 0.40 μm x 25 m)
Carrier gas: He (constant pressure mode: 20 psi)
Oven: (1) Hold at 50 ° C for 10 minutes, (2) Raise to 200 ° C at 10 ° C / min, (3) Hold at 200 ° C for 5 minutes Injection port: 200 ° C, pulsed splitless mode (20 → 40psi, hold 0.5 minutes)
Split ratio: 5.0: 1.0
Detector: 250 ° C (FID)

<Manufacturing equipment>
Hereinafter, the manufacturing apparatus according to the present invention will be described. In the present invention, known ones can be used, but examples of the stirring means in the granulation process include paddle blades, inclined paddle blades, three swept blades, anchor blades, full zone blades (manufactured by Shinko Pantech), and Max Blend. (Manufactured by Sumitomo Heavy Industries, Ltd.), Supermix (manufactured by Satake Chemical Machinery Co., Ltd.), Hi-F mixer (manufactured by Soken Kagaku Co., Ltd.), or the like having a stirring blade can be used. In addition, a stirrer capable of imparting a high shearing force is more preferable. As the high shear stirrer, a stirrer having a stirring chamber formed by a stirring rotor rotating at high speed and a screen provided so as to surround the stirring rotor is preferably used. Specifically, Ultratarax (manufactured by IKA), Polytron (manufactured by Kinematica), T.I. K. Homomixer (manufactured by Tokushu Kagaku Kogyo Co., Ltd.), Clairemix (manufactured by M-Technique), W Motion (manufactured by M-Technique), Cavitron (manufactured by Eurotech), Sharp Flow Mill (manufactured by Pacific Kiko), etc. are used.

Hereinafter, the present invention will be described in more detail with reference to specific manufacturing methods, examples, and comparative examples, but this does not limit the present invention in any way.

[Example 1]
Dispersion medium (water-based medium)
14 parts by mass of sodium phosphate and 4.5 parts by mass of 10% hydrochloric acid were added to 1000 parts by mass of ion-exchanged water in the reaction vessel, and the mixture was kept warm at 65 ° C. for 60 minutes while purging N ₂ . T. K. Using a homomixer (manufactured by Tokushu Kagaku Kogyo), while stirring at 12000 rpm, a calcium chloride aqueous solution in which 7.8 parts by mass of calcium chloride is dissolved in 10 parts by mass of ion-exchanged water is collectively added to contain a dispersion stabilizer. An aqueous medium was prepared.

Polymerizable monomer composition ・ 60 parts by mass of styrene ・ Carbon black (manufactured by Orion Engineerred Carbons, trade name “Printex35”) 7 parts by mass ・ Charge control agent (manufactured by Orient: Bontron E-89) 0.25 parts by mass The above material was put into an attritor disperser (Mitsui Miike Machinery Co., Ltd.) and further dispersed at 220 rpm for 5 hours using zirconia particles having a diameter of 1.7 mm to obtain a composition.

To the above composition: -Styrene 20 parts by mass-n-Butyl acrylate 20 parts by mass-Polar resin 5 parts by mass (Saturation obtained by the condensation polymerization reaction of propylene oxide 2 mol addition of bisphenol A with terephthalic acid and isophthalic acid Polyester resin; weight average molecular weight 13000, acid value 8 mgKOH / g, glass transition temperature 74 ° C)
9 parts by mass of Fischer-Tropsch wax (manufactured by Schumann Sazol, trade name "C80": melting point 83.0 ° C.) was added.

The above material was kept at 65 ° C. in a separate container, and T.I. K. Using a homomixer (manufactured by Tokushu Kagaku Kogyo), it was uniformly dissolved and dispersed at 500 rpm. In addition, 10.0 parts by mass of the polymerization initiator t-hexyl peroxypivalate (manufactured by Nippon Oil & Fats Co., Ltd., trade name "Perhexyl PV", molecular weight: 202, 10-hour half-life temperature: 53.2 ° C.) and a polymerization initiator T-Butylperoxyisobrate (manufactured by Alchema Yoshitomi Co., Ltd., trade name "Luperox 80", molecular weight: 160, 10-hour half-life temperature: 75.0 ° C.) 2.0 parts by mass is dissolved and a polymerizable monomer is dissolved. The composition was prepared.

The polymerizable monomer composition was put into the aqueous medium in the granulation tank, and T.I. K. The mixture was stirred with a homomixer at 10000 rpm for 5 minutes and granulated at pH 5.2. Then, it is transferred to a polymerization tank, and the calculated residual rate of the polymerization initiator t-butylperoxyisobrate becomes 80% at 70 ° C. while stirring the first polymerization step with a paddle stirring blade at 30 times / minute. I went to. An aqueous solution prepared by dissolving 1.0 part by mass of potassium persulfate (molecular weight: 270), which is a polymerization initiator, is added to 10 parts by mass of ion-exchanged water, and the second polymerization step is performed 30 times / minute with a paddle stirring blade. Then, the temperature was raised to 90 ° C., and the temperature was increased for 3 hours.

After completion of the polymerization reaction, the reaction vessel is cooled, 10% hydrochloric acid is added, and the dispersion stabilizer is dissolved while stirring for 2 hours at pH = 2. The emulsion is pressure filtered and further washed with 2000 parts by mass or more of ion-exchanged water. The obtained cake is returned to 1000 parts by mass of ion-exchanged water, 10% hydrochloric acid is added, and the cake is rewashed with stirring at pH = 1 or less for 2 hours. The emulsion was pressure-filtered in the same manner as described above, further washed with 2000 parts by mass or more of ion-exchanged water, sufficiently aerated, dried and wind-classified to obtain black colored particles.

100 parts by mass of the obtained black colored particles, 1.5 parts by mass of hydrophobic silica 1 and 0.3 parts by mass of hydrophobic titanium oxide 1 were added and mixed with Mitsui Henchel Mixer (manufactured by Mitsui Miike Machinery Co., Ltd.). Then, a toner 1 having an external additive was obtained. The physical characteristics of the obtained toner 1 are shown in Table 9.

[Examples 2 to 20, Comparative Examples 1 to 10]
Toners were produced in the same manner as in Example 1 except that the types and contents of each raw material, the timing of adding the third polymerization initiator, and the temperature conditions were changed as described in Table 1.

Of the first polymerization initiator and the second polymerization initiator shown in Table 1, the structures and 10-hour half-life temperatures of the polymerization initiators Perocta ND, Perocta O, and Luperox DI used in Comparative Examples are as follows. is there.

-Perocta ND (manufactured by NOF CORPORATION; 10-hour half-life temperature 40.7 ° C)

・ Per Octa O (manufactured by NOF CORPORATION; 10-hour half-life temperature 65.3 ° C)

・ Luperox DI (manufactured by Arkema Yoshitomi Co., Ltd .; 10-hour half-life temperature 129 ° C)

The toners obtained in Examples 1 to 20 and Comparative Examples 1 to 10 were evaluated in various ways using an evaluation machine. The evaluation results are shown in Table 4. The "residual styrene monomer amount" is a value obtained by the above method.

Various image evaluations were carried out as follows.

<Fixability>
In a low-temperature and low-humidity environment (L / L: temperature 10 ° C., humidity 10% RH), using the evaluation machine described later, the machine and the cartridge filled with toner are in a state of being familiar with the environment (after leaving in the environment for 24 hours). I turned on the power from. Immediately after the weight-up, a horizontal line pattern having a width of 200 μm (width 200 μm, interval 200 μm) was printed out, and the 50th printed image was used for the evaluation of fixability. The fixability was evaluated by rubbing the image with Sylbon paper with a load of 100 g (0.98 N) for 5 round trips, and evaluating the peeling of the image by averaging the reduction rate (%) of the reflection density.

Bond paper with a surface smoothness of 10 sec or less was used for the evaluation. The evaluation criteria are shown below.

<Evaluation of toner storage stability>
The storage stability of the toner was evaluated by weighing 10 g of toner into a 100 ml poly cup, leaving it in a constant temperature layer at 50 ° C. and 55 ° C. for 3 days, and then sieving with 200 mesh (opening). As a measuring device, a powder tester (manufactured by Hosokawa Micron Co., Ltd.) having a digital vibrometer (manufactured by DEGITAL VIBLATIONMENT MODEL 1332 SHOWA SOKKI CORPORATION) was used.

The measurement method is to place the evaluation toner on the set 200 mesh sieve (opening 75 μm), adjust the displacement value of the digital vibrometer to 0.50 mm (peak-to-peak), and adjust it for 30 seconds. Vibration was applied. Then, the storage stability was evaluated from the state of the agglomerates of the toner remaining on each sieve. The evaluation criteria are shown below.

(Evaluation machine)
The process speed of a commercially available LBP-2710 (manufactured by Canon Inc.) was modified to 220 mm / s, toner was extracted from a commercially available black cartridge, and the inside was cleaned with an air blow. Then, 260 g of the toner of the present invention was filled, and the toner of the other cyan, yellow and magenta cartridges was removed and inserted into each station.

Claims (4)

Preparation step for preparing a polymerizable monomer composition containing a polymerizable monomer, a first polymerization initiator and a second polymerization initiator, particles of the polymerizable monomer composition in an aqueous medium. A method for producing toner particles, which comprises a granulation step of forming and a polymerization step of polymerizing the polymerizable monomer contained in the particles of the polymerizable monomer composition.
The first polymerization initiator and the second polymerization initiator are polymerization initiators that are soluble in the polymerizable monomer.
The first polymerization initiator is a compound represented by the following formula (1).

(In the formula (1), R ⁷ , R ⁸ and R ⁹ each independently represent an alkyl group having 1 or more and 5 or less carbon atoms, and R ¹⁰ represents an alkyl group having 1 or more and 6 or less carbon atoms.)
The 10-hour half-life temperature of the first polymerization initiator is 45.0 ° C. or higher and 65.0 ° C. or lower.
The second polymerization initiator is a compound represented by the following formula (2) or (3).

(In the formula (2), R ¹ represents an alkyl group having 1 or more and 8 or less carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms, and R ³ is a hydrogen atom or carbon. Indicates an alkyl group of number 1 or more and 7 or less.)

(In the formula (3), R ⁴ represents an alkyl group having 1 to 8 carbon atoms, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ⁶ represents a hydrogen atom or carbon. Indicates an alkyl group of number 1 or more and 7 or less.)
The 10-hour half-life temperature of the second polymerization initiator is 70.0 ° C. or higher and 115.0 ° C. or lower.
The content of the first polymerization initiator in the polymerizable monomer composition prepared in the preparation step is 2.5 mol% or more and 20.0 mol% or less with respect to the polymerizable monomer. And
The polymerization step is a first polymerization step in which the polymerizable monomer is polymerized by the first polymerization initiator and the second polymerization initiator, and the second polymerization step in the first polymerization step. It has a second polymerization step in which a third polymerization initiator is added to the aqueous medium to further polymerize the polymerizable monomer when the residual ratio of the polymerization initiator is 50% or more.
The third polymerization initiator is a water-soluble polymerization initiator.
When the third polymerization initiator is added to the aqueous medium in the second polymerization step, the residual amount of the second polymerization initiator is 20 with respect to the addition amount of the third polymerization initiator. A method for producing toner particles, which comprises 0.0 mol% or more. The content of the second polymerization initiator in the polymerizable monomer composition prepared in the preparation step is 5.0 mol% or more and 60.0 mol% with respect to the first polymerization initiator. The method for producing toner particles according to claim 1, which is as follows. The amount of the third polymerization initiator added in the second polymerization step is 5 with respect to the content of the second polymerization initiator in the polymerizable monomer composition prepared in the preparation step. The method for producing a toner particle according to claim 1 or 2, wherein the amount is 0.0 mol% or more and 90.0 mol% or less. The method for producing toner particles according to any one of claims 1 to 3, wherein in the first or second polymerization step, the polymerization temperature is raised in the middle of the first or second polymerization step.