JP7034788B2 - Toner and toner manufacturing method - Google Patents

Description

The present invention relates to a toner used in an electrophotographic method, an electrostatic recording method, a magnetic recording method, etc., and a method for manufacturing the toner.

In recent years, image forming devices such as copiers and printers are required to have further energy saving as the purpose of use and the environment of use are diversified. From the viewpoint of improving energy saving by toner, first of all, toner having higher low temperature fixability can be mentioned.
A crystalline material such as wax is used to improve the low temperature fixability of the toner. The crystalline material melts at the melting point of the material, plasticizes the binder resin of the toner, and promotes the melt deformation of the toner. Therefore, it is possible to further improve the low temperature fixability of the toner by lowering the melting point of the crystalline material and increasing the amount used.
On the other hand, when the low temperature fixability is improved by the above method, there arises a problem that the back surface of the media loaded on the image is stuck when the continuously printed media are laminated. Part of the heat received from the fuser remains on the media ejected from the printer, and this heat causes the toner image to melt, causing sticking when the media are stacked. .. Therefore, when the low-temperature fixability is improved by the above method, there is a trade-off relationship between the sticking of the media and the low-temperature fixability during continuous printing.

The situations in which this sticking problem is likely to occur include that the printing environment is a high temperature and high humidity environment, the printed image is a solid black image, the continuous printing speed is high, and the number of laminated media is large. ..
Patent Document 1 describes a method for controlling the dispersed state of domains of a crystalline material in order to improve low temperature fixability and storage stability.
Patent Document 2 describes a method of using a crystalline material having a low melting point in order to improve low temperature fixability and storage stability.
On the other hand, Patent Document 3 describes a method of controlling the charge attenuation coefficient of the charge retained on the toner surface in order to solve the storage stability.

JP-A-2017-102396 International Publication No. 2014/157424 Japanese Unexamined Patent Publication No. 2016-90965

However, although the methods of Patent Documents 1 and 2 improve low-temperature fixability and storage stability, there is room for solving the problem of achieving both low-temperature fixability and suppression of media sticking.
Further, in the method of Patent Document 3, there is room for solving the problem regarding the suppression of sticking of the media.
The present invention is to provide a toner which is excellent in low temperature fixability, can suppress sticking of media, and has good hot offset resistance and developability at the time of fixing.

A toner having toner particles containing a binder resin, a crystalline material, and a colorant.
The charge amount of the toner is -50 μC / g or more and -20 μC / g or less.
The charge decay rate of the toner when measured at 25 ° C is -2.5 x 10 ^-3 (1 / s ^(1/2) ) or more-0.1 x 10 ^-3 (1 / s ⁽ 1/2)). ⁾ ) Below,
The charge decay rate when the toner was heated at 80 ° C. for 1 minute and measured at 25 ° C. was −7.0 × 10 ^-3 (1 / s ^(1/2) ) or more-4.0 × 10 ⁻ . ³ (1 / s ^(1/2) ) or less ,
In the cross section of the toner particles observed by a transmission electron microscope,
The microdomains of the crystalline material are present and
The toner is characterized in that the microdomain is present within 25% of the distance between the contour of the cross section and the center of gravity of the cross section by 60% by number or more and 100% by number or less .

According to the present invention, it is possible to provide a toner which is excellent in low temperature fixability, can suppress sticking of media, and has good hot offset resistance and developability at the time of fixing.

The figure which shows an example of the image forming apparatus The figure which shows an example of the temperature transition of a processing process The figure which shows an example of the calculation of the amount of the minute domain of a crystalline material. Example of charge measuring device

In the present invention, the description of "○○ or more and XX or less" and "○○ to XX" indicating a numerical range means a numerical range including a lower limit and an upper limit which are end points, unless otherwise specified.
The present inventor has found that the above solution can be solved by controlling the charge decay rate of the toner before and after heating, and has reached the present invention.
First, the problem of media sticking will be explained. The present inventors analyze that the following processes influence the occurrence of media sticking.
The media discharged from the fuser retains the heat of the fuser for a certain period of time.
The weight of the stacked media puts pressure on the toner image and the media.
The heat and pressure of the media make it easy for the toner image to melt and deform, and the toner image on the surface of the adjacent media sticks to the back surface of the stacked media.

As a result of further detailed analysis, it was found that the larger the surface potential of the fixed toner image, the higher the electrostatic adhesion between the toner image and the back surface of the media laminated therein, and the more remarkable the sticking occurs. .. The shape of the toner image surface is a rough surface with irregularities because the roughness of the media and the way the toner is placed on the media during development are non-uniform. Therefore, when the surface potential of the image is low, even when the media are laminated, the surface roughness of the toner image causes many gaps between the media and the toner image. On the other hand, the higher the surface potential of the toner image, the easier it is for the media and the toner image to come into close contact with each other, and the more likely it is that sticking will occur.
Generally, in order to improve the developability of toner, it is necessary to increase the electrostatic force of the toner. On the other hand, in order to suppress sticking, it is necessary to lower the surface potential of the toner image after fixing.
Therefore, the present inventors have found that it is important to control the charge decay rate before and after heating the toner in order to suppress sticking.

Therefore, the present invention is as follows.
A toner having toner particles containing a binder resin, a crystalline material, and a colorant.
The charge amount of the toner is -50 μC / g or more and -20 μC / g or less.
The charge decay rate of the toner when measured at 25 ° C is -2.5 x 10 ^-3 (1 / s ^(1/2) ) or more-0.1 x 10 ^-3 (1 / s ⁽ 1/2)). ⁾ ) Below,
The charge decay rate when the toner was heated at 80 ° C. for 1 minute and measured at 25 ° C. was −7.0 × 10 ^-3 (1 / s ^(1/2) ) or more-4.0 × 10 ⁻ . ³ (1 / s ^(1/2) ) or less toner.

The toner particles contain a binder resin, a crystalline material, and a colorant. By containing these, it is possible to control the charge amount and charge decay rate required for the present invention within a good range.
The amount of charge of the toner is −50 μC / g or more and −20 μC / g or less. By controlling the charge amount within this range, good developability can be obtained in a low temperature environment and a high temperature environment.
The amount of charge is preferably −45 μC / g or more and −20 μC / g or less. The amount of charge of the toner can be controlled to increase the amount of charge by reducing the amount of the crystalline material exuding to the surface of the toner particles.

The charge decay rate of the toner when measured at 25 ° C is -2.5 x 10 ^-3 (1 / s ^(1/2) ) or more-0.1 x 10 ^-3 (1 / s ^(1/2)) ) It is as follows. This means that the charge decay rate of the toner is relatively low. As a result, it is easy to keep the developability of the toner in a good range, and it is possible to stably improve the developability particularly in a high temperature and high humidity environment. If the charge decay rate is less than −2.5 × 10 ^-3 (1 / s ^(1/2) ), it means that the charge decay is very fast at 25 ° C. In this case, good developability may not be obtained because the chargeability of the toner required for development tends to be attenuated.
The charge decay rate of the toner when measured at 25 ° C. is preferably −2.1 × 10 ^-3 (1 / s ^(1/2) ) or more and −0.1 × 10 ^-3 (1 / s ⁽¹ / s)). ²⁾ ) It is as follows.

Further, the charge decay rate (hereinafter, also referred to as “charge decay rate after heating”) when the sample obtained by heating the toner at 80 ° C. for 1 minute is measured at 25 ° C. is −7.0 × 10 ^-3 (1 /). s ^(1/2) ) or more-4.0 × 10 ^-3 (1 / s ^(1/2) ) or less. This means that the charge decay rate is relatively fast.
By satisfying the above range, the charge decay rate of the toner image after fixing is sufficiently high, so that the surface potential of the toner image tends to decrease. Therefore, when the media are laminated, the electrostatic adhesion between the media and the toner image is low, so that they are difficult to adhere to each other, and sticking can be effectively reduced.
If the charge decay rate after heating is less than −7.0 × 10 ^-3 (1 / s ^(1/2) ), it means that the charge decay rate is very fast. In this case, the charge decay rate is too fast, the surface potential of the toner image tends to be very low, and hot offset around the fuser tends to occur.
Further, when the charge decay rate after heating is higher than -4.0 × 10 ^-3 (1 / s ^(1/2) ), it means that the charge decay rate is relatively slow. In this case, the surface potential of the toner image tends to be high, and the electrostatic adhesion with the medium is high, so that it is difficult to suppress sticking.
The charge decay rate after heating is preferably −7.0 × 10 ^-3 (1 / s ^(1/2) ) or more and −5.0 × 10 ^-3 (1 / s ^(1/2) ) or less. ..

The measurement of the charge decay rate will be described. Measure according to the following procedure. The following is a procedure for measuring the charge decay rate when the toner is measured at 25 ° C. The detailed measurement method will be described later.
Prepare a measurement sample in which toner is placed in a sample pan.
Corona charging is performed on the measurement sample to apply a negative surface potential.
In an environment of 25 ° C., the surface potential V of the measurement sample is measured hourly with a surface electrometer. Note that V ₀ indicates the surface potential at the measurement time of 0 seconds.
The charge decay rate α is calculated from the equation ln (V _t / V ₀ ) = −αt ^(1/2) .
The charge decay rate α obtained as described above is the charge decay rate at 25 ° C. If the charge decay rate is negatively large, it means that the charge decay rate is high.

Subsequently, a procedure for measuring the charge decay rate when measured at 25 ° C. after heating at 80 ° C. for 1 minute will be described. The detailed measurement method will be described later.
Make a measurement sample.
The measurement sample is placed in a constant temperature bath whose temperature has been adjusted to 80 ° C., and is taken out after 1 minute.
Corona charging is performed on the measurement sample to apply a negative surface potential.
In an environment of 25 ° C., the surface potential V of the measurement sample is measured hourly with a surface electrometer. Note that V ₀ indicates the surface potential at the measurement time of 0 seconds.
The charge decay rate α is calculated from the equation ln (V _t / V ₀ ) = −αt ^(1/2) .
The charge decay rate α obtained as described above is the charge decay rate after heating. When the charge decay rate after heating is negatively large, it means that the charge decay after heating is fast at 80 ° C.
The surface potential after corona charging gradually decreases with time, and the rate of decrease tends to be slow. It is possible to calculate the electrification decay rate based on the decay data of the surface potential. The calculation method will be described later.

In order to calculate the charge decay rate, the surface potential from 5 seconds to 95 seconds after the start of measurement is used. Since the phenomenon that the toner image adheres to the media laminated on it due to the electrostatic adhesion force occurs within a few seconds to several tens of seconds, it is considered that the charge decay rate is important to capture this phenomenon.
As the charge decay rate after heating, the sample after heating the toner at 80 ° C. for 1 minute is measured. When the temperature of the fuser for fixing the toner is, for example, 160 ° C., the heat actually received by the toner is analyzed and found to be about 60 to 100 ° C. lower than 160 ° C. Therefore, a temperature of 80 ° C. and a time of 1 minute were selected as measurement conditions that well represent the state of the toner that received heat during fixing.

In the present invention, the cross section of the toner particles is dyed so that the crystalline material can be easily observed, and the region having the lamellar structure confirmed by the transmission electron microscope TEM observation of the cross section is defined as the domain of the crystalline material. Further, a domain having a domain major axis of 10 nm or more and 1000 nm or less is referred to as a microdomain in the present invention. Further, a domain having a domain major axis exceeding 1000 nm is hereinafter referred to as a large domain. The detailed measurement method of the micro domain will be described later.

In the cross section of the toner particles observed by a transmission electron microscope,
It is preferable that microdomains of the crystalline material are present and the number average value of the major axis of the microdomains is 50 nm or more and 350 nm or less.
When the number average value of the major axis of the microdomain is in the above range, the crystalline material can be effectively exuded on the surface of the toner particles during heating. Since the crystalline material has a lamellar structure, the electrical conductivity tends to be high. Therefore, since the crystalline material exudes to the surface of the toner particles, it becomes easy to control the charge decay rate of the toner after heating within the above range.
Further, since the fine domains in the major axis range are dispersed in the binder resin, the crystalline material can effectively plastic the binder resin during heating, and the low temperature fixability is greatly improved. .. The number average value of the major axis of the microdomain is more preferably 100 nm or more and 250 nm or less.

Further, in the toner particle cross section observed by the transmission electron microscope, microdomains are present within 25% of the distance between the contour and the center of gravity of the cross section from the contour of the cross section by 60% or more and 100% or less. It is preferable to do so. This means that a large amount of microdomains are locally present near the surface of the toner particles.
In order to increase the charge decay rate of the toner after heating, it is one of the important means to effectively exude the fine domains of the crystalline material onto the surface of the toner particles. Therefore, it is preferable that the minute domain exists in the vicinity of the surface of the toner particles in the range of the above number%, which makes it easy to increase the charge decay rate after heating. A more preferable range is 65 pieces% or more and 100 pieces% or less, and a further preferable range is 70 pieces% or more and 100 pieces% or less. The method of calculating the ratio (hereinafter, also referred to as 25% ratio) in which the minute domain exists within 25% of the distance between the contour and the center of gravity of the cross section from the contour of the cross section will be described later.
As a method for controlling the presence state of the minute domain of the crystalline material, the charge decay rate at 25 ° C., and the charge decay rate after heating, it is preferable to manufacture the toner by a suspension polymerization method and to perform a cooling step described later. ..

Next, the crystalline material will be described.
A crystalline material is a material that exhibits a clear melting point in differential scanning calorimetry.
The crystalline material is not particularly limited, and examples thereof include a mold release agent and a crystalline polyester resin. The melting point of the crystalline material is preferably 50.0 ° C. or higher and 85.0 ° C. or lower.
Examples of the release agent include the following. Fatty hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystallin wax, fishertropush wax, paraffin wax; oxides of fatty hydrocarbon waxes such as polyethylene oxide wax, or block copolymers thereof. Deoxidized fatty acid esters such as carnauba wax and montanic acid ester wax, which are mainly composed of fatty acid esters, and partially or wholly deoxidized fatty acid esters such as deoxidized carnauba wax; palmitic acid, stearic acid, montanic acid, etc. Saturated linear fatty acids; unsaturated fatty acids such as brushzic acid, eleostearic acid, parinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, ceryl alcohol, mericyl alcohol; sorbitol Polyhydric alcohols such as; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bisstearic acid amide, etc. Saturated fatty acid bisamides; unsaturated fatty acid amides such as ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N'diorail adipic acid amide, N, N'diorail sevacinic acid amide; m-xylene bisstearate. Aromatic bisamides such as acid amide, N, N'distearyl isophthalic acid amide; fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate (generally referred to as metal soap); Waxes grafted on aliphatic hydrocarbon wax using vinyl monomer such as styrene and acrylic acid; partial esterified product of fatty acid such as behenic acid monoglyceride and polyhydric alcohol; obtained by hydrogenation of vegetable fats and oils Examples thereof include methyl ester compounds having a hydroxyl group.

When a wax containing a fatty acid ester as a main component (hereinafter referred to as ester wax) is used as a mold release agent, the binder resin is easily plasticized and the low temperature fixability is easily improved. Further, in a specific production method, it is preferable because it is easy to form a microdomain and it is easy to control it into a suitable shape of the present invention.

In the present invention, it is preferable that the crystalline material contains a monoester compound. The monoester compound means an ester compound in which the number of ester groups contained in one molecule is one.

The melting point of the monoester compound is preferably 60 ° C. or higher and 72 ° C. or lower, and more preferably 60 ° C. or higher and 70 ° C. or lower. When the melting point is in the above range, it is possible to effectively improve the low temperature fixability of the toner. Further, by controlling the charge decay rate of the toner after heating within a predetermined range, it becomes easy to solve the sticking problem at the same time.

Examples of the aliphatic alcohol that can be used for the monoester compound include the following.
1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, undecyl alcohol, lauryl alcohol, myristyl alcohol, 1-hexadecanol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, lignoceryl alcohol.
On the other hand, examples of aliphatic carboxylic acids include pentanoic acid, hexanoic acid, heptanic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and lignoceric acid. Can be mentioned.
The average number of carbon atoms per molecule of the monoester compound is preferably 36 or more and 42 or less. A monoester compound having an average carbon number of 36 or more has a lamellar structure due to a relatively long alkyl chain, and tends to have high electrical conductivity. Therefore, it is easy to control the charge decay rate of the toner after heating within a specific range. Further, a monoester compound having an average carbon number of 42 or less is preferable because the monoester compound easily sufficiently plasticizes the binder resin when the toner receives heat. The average carbon number is more preferably 36 or more and 40 or less.

As the monoester compound, a condensate of an aliphatic alcohol having 6 to 24 carbon atoms and a long-chain carboxylic acid, or a condensate of an aliphatic carboxylic acid having 4 to 24 carbon atoms and a long-chain alcohol can be used. Here, any long-chain carboxylic acid or long-chain alcohol can be used, but a combination capable of satisfying the above melting point is preferable.
The content of the monoester compound is preferably 13 to 40 parts by mass, and more preferably 15 to 35 parts by mass with respect to 100 parts by mass of the binder resin.

It is preferred that the crystalline material contains a hydrocarbon wax in order to facilitate control of the 25% ratio to a particular range.
Hydrocarbon wax is known to crystallize in the form of stacked linear hydrocarbon chain portions, and examples thereof include paraffin wax and Fischer-Tropsch wax.
In the suspension polymerization method, the hydrocarbon wax tends to form a large domain near the center of the toner particles. Therefore, it becomes easy to locally unevenly distribute the minute domains in the vicinity of the surface of the toner particles, and it becomes easy to control the 25% ratio within the above range. In addition, when the presence state of the minute domain is not controlled and uniformly dispersed inside the toner particles, the theory of the amount existing within 25% of the distance between the contour and the center of gravity of the cross section from the contour of the cross section. The value is 42 pieces%.
The content of the hydrocarbon wax is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the binder resin.

The content of the crystalline material is preferably 3 parts by mass or more and 40 parts by mass or less, and more preferably 20 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the binder resin. When the amount is 3 parts by mass or more, the low temperature fixing property is improved, and it becomes easier to control the charge decay rate of the toner after heating. Further, by setting the content to 35 parts by mass or less, it is possible to maintain good hot offset resistance and storage stability.

The binder resin used for the toner is a homopolymer of styrene such as polystyrene and polyvinyltoluene and its substitution product; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer, styrene. -Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methacrylic acid Methyl acid acid copolymer, styrene-ethyl methacrylic acid copolymer, styrene-butyl methacrylic acid copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinylmethyl ether copolymer, styrene-vinyl ethyl Styre-based copolymers such as ether copolymers, styrene-vinylmethylketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers. Combined; Examples thereof include polymethylmethacrylate, polybutylmethacrylate, polyvinylacetate, polyethylene, polypropylene, polyvinylbutyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin and the like.
These can be used alone or in combination of two or more. Of these, a styrene-based copolymer typified by styrene-butyl acrylate is particularly preferable in terms of development characteristics, fixability, and the like. Further, the binder resin can also be used in combination with other known resins.

Examples of the polymerizable monomer forming the styrene-based copolymer include the following.
Examples of the styrene-based polymerizable monomer include styrene; styrene-based polymerizable monomers such as α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and p-methoxystyrene.
Examples of the acrylic polymerizable monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-hexyl acrylate, and 2-ethylhexyl acrylate. , N-octyl acrylate, cyclohexyl acrylate and other krill-based polymerizable monomers.
Examples of the methacrylic polymerizable monomer include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, and 2-ethylhexyl methacrylate. , N-Methyl-based polymerizable monomers such as octyl methacrylate.
The method for producing the styrene-based copolymer is not particularly limited, and a known method can be used.

Examples of the colorant include the following organic pigments, organic dyes, and inorganic pigments.
Examples of the cyan-based colorant include a copper phthalocyanine compound and its derivative, an anthraquinone compound, and a basic dye lake compound.
Examples of the magenta colorant include the following. Condensed azo compound, diketopyrrolopyrrole compound, anthraquinone compound, quinacridone compound, basic dye lake compound, naphthol compound, benzimidazolone compound, thioindigo compound, and perylene compound.
Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.
Examples of the black colorant include carbon black, the above-mentioned yellow colorant, magenta colorant, cyan colorant, and those colored black using a magnetic material.
These colorants can be used alone or in a mixed state or in a solid solution state. The colorant is selected in terms of hue angle, saturation, lightness, light resistance, OHP transparency, and dispersibility in toner particles. The content of the colorant is preferably 0.1 part by mass or more and 60.0 parts by mass or less, and more preferably 0.5 parts by mass or more and 50.0 parts by mass or less with respect to 100 parts by mass of the binder resin. Is.

A magnetic material can also be used as the toner. The magnetic substance is mainly composed of magnetic iron oxide such as triiron tetraoxide and γ-iron oxide, and may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum and silicon. These magnetic materials preferably have a BET specific surface area of 2 to 30 m ² / g by the nitrogen adsorption method, and more preferably 3 to 28 m ² / g. Further, those having a Mohs hardness of 5 to 7 are preferable. The shape of the magnetic material includes a polyhedron, an octahedron, a hexahedron, a sphere, a needle, and a scaly shape. Preferred above.
The magnetic material preferably has a number average particle size of 0.10 to 0.40 μm. Generally, the smaller the particle size of the magnetic material, the higher the coloring power, but the magnetic material tends to aggregate. Therefore, the above range is preferable from the viewpoint of the balance between the coloring power and the cohesiveness.

The average particle size of the magnetic material can be measured using a transmission electron microscope. Specifically, after sufficiently dispersing the toner to be observed in the epoxy resin, it is cured in an atmosphere at a temperature of 40 ° C. for 2 days to obtain a cured product. The obtained cured product is used as a flaky sample by a microtome, and the diameters of 100 magnetic particles in the field of view are measured with a photograph having a magnification of 10,000 to 40,000 times with a transmission electron microscope (TEM). Then, the number average particle diameter is calculated based on the equivalent diameter of the circle equal to the projected area of the magnetic material. It is also possible to measure the particle size with an image analyzer.

The magnetic material can be produced, for example, by the following method. To the ferrous salt aqueous solution, an alkali such as sodium hydroxide having an equivalent amount or an equivalent amount or more is added to the iron component to prepare an aqueous solution containing ferrous hydroxide. Air is blown while maintaining the pH of the prepared aqueous solution at pH 7 or higher, and the oxidation reaction of ferrous hydroxide is carried out while heating the aqueous solution to 70 ° C. or higher to first form seed crystals that are the core of the magnetic iron oxide powder. Generate.
Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the liquid at 5 to 10, the reaction of ferrous hydroxide is promoted while blowing air, and the magnetic iron oxide powder is grown around the seed crystal. At this time, it is possible to control the shape and magnetic characteristics of the magnetic material by selecting an arbitrary pH, reaction temperature, and stirring conditions. As the oxidation reaction progresses, the pH of the liquid shifts to the acidic side, but it is preferable that the pH of the liquid is not less than 5. The magnetic material thus obtained can be obtained by filtering, washing and drying the magnetic material by a conventional method.

Further, when the toner is produced in an aqueous medium, it is very preferable to hydrophobize the surface of the magnetic material. When surface treatment is performed by a dry method, a coupling agent treatment is performed on the washed, filtered, and dried magnetic material. In the case of wet surface treatment, after the oxidation reaction is completed, the dried material is redispersed, or after the oxidation reaction is completed, the magnetic material obtained by washing and filtering is placed in another aqueous medium without drying. Redisperse and perform coupling processing. Both the dry method and the wet method can be appropriately selected.

Examples of the coupling agent that can be used in the surface treatment of the magnetic material include a silane coupling agent and a titanium coupling agent. More preferably used is a silane coupling agent, which is represented by the general formula (I).
R _m SiY _n (I)
[In the formula, R represents an alkoxy group (preferably having 1 to 6 carbon atoms), m represents an integer of 1 to 3, and Y represents a functional group such as an alkyl group, a vinyl group, an epoxy group, or a (meth) acrylic group. The group is shown, and n is an integer of 1 to 3. However, m + n = 4. ]
It is preferable that Y is an alkyl group, more preferably an alkyl group having 3 or more carbon atoms and 6 or less carbon atoms, and particularly preferably an alkyl group having 3 or 4 carbon atoms.

When a silane coupling agent is used, it can be treated alone or in combination of a plurality of types. When a plurality of types are used in combination, they may be treated individually with each coupling agent or may be treated at the same time.
The total amount of the coupling agent to be treated is preferably 0.9 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the magnetic material, depending on the surface area of the magnetic material, the reactivity of the coupling agent and the like. It is important to adjust the amount of treatment agent.

In addition to the magnetic material, other colorants may be used in combination. Examples of the colorant that can be used in combination include magnetic or non-magnetic inorganic compounds in addition to the above-mentioned known dyes and pigments. Specifically, ferromagnetic metal particles such as cobalt and nickel, or alloys obtained by adding chromium, manganese, copper, zinc, aluminum, rare earth elements, etc. to these. Particles such as hematite, titanium black, niglocin dye / pigment, carbon black, phthalocyanine and the like can be mentioned. It is also preferable to treat these surfaces before use.
The content of the magnetic substance in the toner can be measured by using a thermal analyzer TGA7 manufactured by PerkinElmer. The measurement method is as follows. The toner is heated from room temperature to 900 ° C. at a heating rate of 25 ° C./min in a nitrogen atmosphere. The weight loss mass% between 100 ° C. and 750 ° C. is defined as the amount of binder resin, and the residual mass is approximately defined as the amount of magnetic material.

The colorant contains a magnetic substance, and the surface vicinity index of the magnetic substance obtained by observing the toner with a scanning electron microscope is preferably 4.0 pieces / 1 μm ² or more and 8.0 pieces / 1 μm ² or less, preferably 6 It is more preferable that the number is 0.0 pieces / 1 μm ² or more and 8.0 pieces / 1 μm ² or less. The near-surface existence index of the magnetic material is the number of magnetic materials existing near the surface of the toner particles, and indicates the number per 1 μm ² of the surface area.
When the exponent is in the range of 4.0 pieces / 1 μm ² or more and 8.0 pieces / 1 μm ² or less, it means that the magnetic material is unevenly distributed near the surface of the toner particles. As a result, since a large amount of magnetic material is present on the surface of the toner image after fixing, it becomes easy to form irregularities on the image. Therefore, by simultaneously achieving the above-mentioned range of the charge decay rate of the toner after heating and the surface proximity index of the magnetic material, it becomes easy to greatly improve the sticking problem in the toner having improved low temperature fixability.

The index can be controlled by the dispersion strength in the dispersion step of the magnetic material. By increasing the dispersion strength, the magnetic material is crushed and can be dispersed as primary particles in the toner. Further, in order to increase the exponent, a means for increasing the number of copies of the magnetic material may be combined.
The amount of the magnetic material added is preferably 40 parts by mass or more and 200 parts by mass or less with respect to 100.0 parts by mass of the binder resin. More preferably, it is 90 parts by mass or more and 160 parts by mass or less.

A charge control agent may be used as the toner, if necessary. As the charge control agent, known ones can be used, but a charge control agent having a high triboelectric rate and capable of stably maintaining a constant triboelectric charge amount is preferable. Further, when the toner particles are produced by the suspension polymerization method, a charge control agent having low polymerization inhibitory property and substantially no solubilized material in an aqueous medium is preferable.

As the charge control agent, there are those that control the toner to load electrical and those that control the toner to positive charge. Examples of the one that controls the toner to be load-electric are as follows. Monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids or dicarboxylic acid-based metal compounds, aromatic oxycarboxylic acids, aromatic mono or polycarboxylic acids or metal salts thereof, Examples thereof include anhydrides or esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, boron compounds, quaternary ammonium salts, calix array, and charge control resins.
The charge control agent can be used alone or in combination of two or more.
Among these charge control agents, metal-containing salicylic acid-based compounds are preferable, and those whose metal is aluminum or zirconium are particularly preferable.
The amount of the charge control agent added is preferably 0.01 parts by mass or more and 20.0 parts by mass or less, more preferably 0.5 parts by mass or more and 10.0 parts by mass with respect to 100.0 parts by mass of the binder resin. It is less than a part.

Further, as the charge control resin, it is preferable to use a polymer or a copolymer having a sulfonic acid group, a sulfonic acid base or a sulfonic acid ester group. As the polymer having a sulfonic acid group, a sulfonic acid base or a sulfonic acid ester group, it is particularly preferable to contain 2% by mass or more of a sulfonic acid group-containing acrylamide-based monomer or a sulfonic acid group-containing methacrylamide-based monomer in a copolymerization ratio. .. More preferably, it is contained in an copolymerization ratio of 5% by mass or more.
The charge control resin has a glass transition temperature (Tg) of 35 ° C. or higher and 90 ° C. or lower, a peak molecular weight (Mp) of 10,000 or higher and 30,000 or lower, and a weight average molecular weight (Mn) of 25,000 or higher and 50,000 or lower. Some are preferred. When this charge control resin is used, preferable triboelectric charge characteristics can be imparted without affecting the thermal characteristics required for the toner particles. Furthermore, since the charge control resin contains a sulfonic acid group, the dispersibility of the charge control resin itself in the dispersion liquid of the colorant and the dispersibility of the colorant are improved, and the coloring power, transparency, and triboelectric charging are improved. The characteristics can be further improved.

The weight average particle size (D4) of the toner is preferably 3.0 μm or more and 12.0 μm or less, and more preferably 4.0 μm or more and 10.0 μm or less. When the weight average particle size (D4) is in the above range, good fluidity can be obtained and the latent image can be faithfully developed.

Any known method may be used for producing the toner particles.
For example, in the case of production by the pulverization method, the binder resin, the colorant, and the crystalline material, and if necessary, other additives and the like are sufficiently mixed with a mixer such as a Henschel mixer or a ball mill. After that, various materials are dispersed or melted by melt-kneading using a heat kneader such as a heating roll, a kneader, or an extruder, and the toner is subjected to a cooling solidification step, a crushing step, a classification step, and a surface treatment step if necessary. Get the particles.
In the crushing step, a known crushing device such as a mechanical impact type or a jet type may be used. In addition, either of the order of the classification step and the surface treatment step may come first. In the classification process, it is preferable to use a multi-division classifier in terms of production efficiency.

When toner particles are produced by a dry method as in the pulverization method, after the toner particles are obtained, the toner particles are dispersed in an aqueous medium to obtain a dispersion liquid, and then a specific step including a cooling step described later is performed. It is good.
At that time, it is advisable to use known surfactants, organic dispersants and inorganic dispersants as dispersants so that the toner particles do not easily coalesce when they receive heat in the aqueous medium, as will be described later. It is preferable that the dispersion liquid contains a poorly water-soluble inorganic dispersant.
The poorly water-soluble inorganic dispersant does not easily generate harmful ultrafine powder, and its steric hindrance gives dispersion stability, so that the stability does not easily collapse even if the reaction temperature is changed. In addition, it is preferable because it is easy to clean and does not adversely affect the toner. Further, the poorly water-soluble inorganic dispersant has a high polarity, and it is difficult to precipitate a hydrophobic crystalline material on the surface of the toner particles.

Further, as a method for producing toner particles, a suspension polymerization method and an emulsification / aggregation method can be preferably exemplified. When the toner particles are produced by using the suspension polymerization method and the emulsification / aggregation method, the toner particles are produced in an aqueous medium, so that they can be easily incorporated into the production process. In these manufacturing methods, it is easy to sharpen the particle size distribution of the toner particles and to increase the average circularity of the toner particles. It is also possible to use toner particles having a core-shell structure.
Hereinafter, examples of producing toner particles using the suspension polymerization method will be described in detail, but the present invention is not limited thereto.

The method for producing toner particles using the suspension polymerization method is as follows.
First, a polymerizable monomer, a colorant and a crystalline material capable of producing a binder resin, and, if necessary, a polymerization initiator, a cross-linking agent, a charge control agent, and other additives are uniformly dissolved or dispersed. To obtain a polymerizable monomer composition.
Next, the polymerizable monomer composition is dispersed in a continuous layer (for example, an aqueous medium) containing a dispersant using an appropriate stirrer, and the polymerizable monomer composition is dispersed in the aqueous medium. Form particles.
Next, the polymerizable monomer contained in the particles of the polymerizable monomer composition is polymerized to obtain toner particles having a desired particle size.
The stirring strength of the stirrer may be selected in consideration of material dispersibility, productivity and the like.

When a magnetic material is used as the colorant, it is preferable to increase the stirring strength of the stirrer that disperses the magnetic material because it is easy to control the presence index near the surface of the magnetic material within a desired range. As the method, it is preferable to modify the motor of the stirrer to change the rotation speed in order to increase the dispersion strength, or to use a stirrer having a stirring blade capable of increasing the dispersion strength.
The polymerization initiator may be added at the same time as the polymerizable monomer and other additives are added, or may be mixed immediately before the polymerizable monomer composition is dispersed in the aqueous medium. .. Further, it is also possible to add a polymerization initiator dissolved in a polymerizable monomer or a solvent immediately after forming the particles of the polymerizable monomer composition and before starting the polymerization reaction.
When the above-mentioned polymerizable monomer is polymerized, the polymerization temperature is usually 40 ° C. or higher, preferably 50 ° C. or higher and 90 ° C. or lower.

As the polymerizable monomer, those exemplified as the polymerizable monomer forming the above-mentioned styrene-based copolymer are preferable.
The polymerization initiator preferably has a half-life of 0.5 hours or more and 30 hours or less at the time of the polymerization reaction. Further, when the polymerization reaction is carried out by using an addition amount of 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer, it becomes easy to obtain a polymer having a maximum molecular weight of 5000 to 50,000. ..

Specific polymerization initiators include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, and 1,1'-azobis (cyclohexane-1-carbo). Azo-based or diazo-based polymerization initiators such as nitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy. Peroxide-based polymerization initiators such as carbonate, cumenehydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy2-ethylhexanoate, and t-butylperoxypivalate. Be done.

As the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; divinyl. Divinyl compounds such as aniline, divinyl ether, divinyl sulfide, and divinyl sulfone; and compounds having three or more vinyl groups; These may be used alone or as a mixture of two or more.
The amount of the cross-linking agent added is preferably 0.1 part by mass or more and 10.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

As the dispersant, known surfactants, organic dispersants and poorly water-soluble inorganic dispersants can be used. Examples of the inorganic dispersant include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, hydroxyapatite and other phosphate polyvalent metal salts, calcium carbonate, magnesium carbonate and other carbonates, and metapolyacid. Examples thereof include inorganic salts such as calcium, calcium sulfate and barium sulfate, and inorganic compounds such as calcium hydroxide, magnesium hydroxide and aluminum hydroxide.
Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecylsulfate, sodium pentadecylsulfate, sodium octylsulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.
The amount of the inorganic dispersant added is preferably 0.2 parts by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. Further, the above-mentioned dispersant may be used alone or in combination of two or more. Further, a surfactant of 0.1 part by mass or more and 10.0 parts by mass or less may be used in combination.
When an inorganic dispersant is used, it may be used as it is, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of tricalcium phosphate, water-insoluble calcium phosphate can be produced by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring, enabling more uniform and fine dispersion. ..

When the toner particles are produced by the suspension polymerization method or the emulsification / aggregation method, the toner particles are obtained in a state of being dispersed in an aqueous medium, and therefore, it is preferable to continuously perform a specific step including the following cooling step.
Hereinafter, steps (1), (2) and (3) will be described with reference to specific examples, but the present invention is not limited thereto.
FIG. 2 schematically shows the transition of the temperature of the dispersion liquid in which the toner particles are dispersed in the aqueous medium in the steps (1) to (3).
In FIG. 2, 601 indicates a step (1), 602 indicates a step (2), and 603 indicates a step (3).
609 indicates the glass transition temperature Tg (° C.) of the toner particles, and 607 indicates the crystallization temperature Tc (° C.) of the crystalline material.

In the step (1), the temperature of the dispersion liquid is set to be higher than the higher temperature of the crystallization temperature Tc (° C.) of the crystalline material and the glass transition temperature Tg (° C.) of the toner particles. When a plurality of crystalline materials are used, the value of the crystalline material having the highest crystallization temperature is used for Tc.
604 indicates the temperature immediately before cooling the dispersion liquid, and is set as the starting temperature T1.
605 indicates the temperature immediately after the cooling of the dispersion liquid is completed, and is set as the stop temperature T2.
Subsequently, in step (3), the temperature of the dispersion is maintained in order to promote the formation and growth of crystal nuclei of the crystalline material. 608 and 610 are lines indicating Tg + 10 ° C. and Tg-10 ° C., respectively. 605 is the holding start temperature T3, and 606 indicates the temperature T4 of the dispersion liquid at the time when 30 minutes have elapsed from the time when the step (3) was started. 611 and 612 indicate the cooling rate 1 related to T1 to T2 and the cooling rate 2 related to T3 to T4. The cooling rate 1 and the cooling rate 2 are calculated by the following equations.
Cooling rate 1 = (T2 (° C.)-T1 (° C.)) / Time required for cooling (minutes)
Cooling rate 2 = (T3 (° C) -T4 (° C)) / 30 (minutes)

In the step (1), the dispersion liquid in which the toner particles containing the binder resin, the colorant, and the crystalline material are dispersed in the aqueous medium is subjected to the crystallization temperature Tc (° C.) of the crystalline material and the glass of the toner particles. This is a step of setting the temperature higher than the higher of the transition temperatures Tg (° C.). By this operation, the crystalline material and the binder resin can be mixed at the molecular level.
Here, for example, when the toner particles are produced in an aqueous medium by a polymerization method, the polymerization temperature is high at the crystallization temperature Tc (° C.) of the crystalline material or the glass transition temperature Tg (° C.) of the toner particles. If the temperature exceeds that of the other, this operation is not necessary.
Further, in the step (1), for the purpose of more uniformly melting the crystalline material and the binder resin contained in the toner particles, the dispersion liquid is subjected to the crystallization temperature Tc (° C.) of the crystalline material and the glass of the toner particles. It is preferable to keep the temperature at a temperature higher than the higher of the transition temperatures Tg (° C.) for a certain period of time. The holding time is preferably 30 minutes or more, more preferably 90 minutes or more, still more preferably 120 minutes or more. On the other hand, the upper limit of the holding time is considered to be about 1440 minutes or less at which the effect is saturated.

When the treatment of the step (2) and the step (3) is performed, the hydrophobic crystalline material is confined inside the toner particles by carrying out the treatment in an aqueous medium. Therefore, it is possible to suppress the presence of the crystalline material on the surface of the obtained toner particles.
On the other hand, when the step (2) or (3) is performed in the air, in an oxygen atmosphere, in a nitrogen atmosphere, or in a high humidity environment, the crystalline material is hydrophobic, so that it is crystallized and stored on the surface of the toner particles. The sex tends to decrease.
Similarly, when the step (3) and the drying step are made the same, the crystalline material tends to crystallize on the surface of the toner particles for the same reason, and the storage stability tends to decrease.
When the toner particles are produced by a dry method such as a pulverization method, it is preferable to disperse the obtained toner particles in an aqueous medium to obtain a dispersion liquid. When the toner particles are manufactured by a wet method such as a suspension polymerization method or an emulsification / aggregation method, the toner particles are already dispersed in the aqueous medium, so that it is not necessary to disperse the toner particles in the aqueous medium again.

In the step (2), the dispersion liquid in which the toner particles are dispersed is heated from a temperature higher than the higher of the crystallization temperature Tc (° C.) of the crystalline material and the glass transition temperature Tg (° C.) of the toner particles. This is a step of cooling to a temperature of Tg (° C.) or less at a cooling rate of 5.00 ° C./min or more.
Further, in the step (2), the dispersion liquid in which the toner particles are dispersed is 5 ° C. or higher than the higher temperature of the crystallization temperature Tc (° C.) of the crystalline material and the glass transition temperature Tg (° C.) of the toner particles. Cooling at a cooling rate of 5.00 ° C./min or higher from a temperature as high as 22 ° C. or lower (more preferably 10 ° C. or higher and 22 ° C. or lower) to a temperature of Tg (° C.) or lower (more preferably Tg-3 ° C. or lower). It is preferable that the step is to perform.

Further, it is preferable that the crystallization temperature Tc (° C.) is 10 ° C. or higher (more preferably 15 ° C. or higher and 40 ° C. or lower, still more preferably 15 ° C. or higher and 30 ° C. or lower) higher than the glass transition temperature Tg (° C.).
When the crystallization temperature Tc (° C.) is higher than the glass transition temperature Tg (° C.) by 10 ° C. or higher, the temperature of the dispersion is 5 ° C. or higher and 22 ° C. or lower higher than the crystallization temperature Tc (° C.). When cooled to a temperature of Tg (° C.) or lower at a cooling rate of 5.00 ° C./min or higher, it becomes easier to control the dispersion state and crystallization degree of the crystalline material in the toner, and the low-temperature fixability and low-temperature fixability are improved. The storage stability is further improved.

In the steps (1) and (2), the glass transition temperature Tg (° C.) of the toner may be used as the glass transition temperature Tg (° C.) of the toner particles.
As a means for rapidly cooling the temperature of the dispersion liquid, for example, an operation of mixing cold water or ice, an operation of bubbling the dispersion liquid with cold air, an operation of removing heat of the dispersion liquid using a heat exchanger, etc. are used. It is possible.

The cooling rate is preferably 50.00 ° C./min or higher, more preferably 10.00 ° C./min or higher, further preferably 100.00 ° C./min or higher, and particularly preferably 130.00 ° C./min or higher. On the other hand, the upper limit of the cooling rate is about 3000 ° C./min or less at which the effect is saturated.

The step (3) is a step of holding the dispersion liquid that has undergone the step (2) in a temperature range of Tg ± 10 ° C. (preferably in a temperature range of Tg ± 5 ° C.) for 30 minutes or more.
In this step, the crystallinity is improved by forming crystal nuclei of a crystalline material and growing crystals inside the toner particles. Crystal nucleation and crystal growth can be carried out in the temperature range described above. By maintaining the temperature of the dispersion in this temperature range, the molecules of the crystalline material gradually move and begin to form crystal nuclei. By further maintaining the temperature, the molecules of the crystalline material move further, and crystal growth is performed with the crystal nucleus formed earlier as a base point.
It is preferable that the temperature of the dispersion liquid is maintained within the above-mentioned temperature range for a certain period of time. In order to sufficiently improve the crystallinity, the holding time is preferably 30 minutes or more, more preferably 90 minutes or more, and further preferably 120 minutes or more. On the other hand, the upper limit of the holding time is about 1440 minutes or less at which the effect is saturated.

When the cooling stop temperature T2 is lower than the above-mentioned temperature range, the dispersion may be heated again to be within the above-mentioned temperature range, and then the temperature may be maintained.
If the temperature range is out of the above temperature range during the step (3), the temperature of the dispersion liquid may be adjusted again. In that case, the cumulative time satisfying the above-mentioned temperature region is set as the holding time, and if the holding time is 30 minutes or more, it becomes easy to obtain the toner suitable for the present invention.
When the resin is held in a temperature range of less than Tg-10 ° C., the binder resin is sufficiently solidified, so that it becomes difficult for the compatible crystalline material to form crystal nuclei.
Further, when the toner is held in a higher temperature range of Tg + 10 ° C., the binder resin is not solidified, so that the storage stability may be deteriorated as in the case of the toner which has not been rapidly cooled in the step (2). ..

The formation of crystal nuclei and crystal growth of crystalline materials are phenomena promoted by controlling them in a certain temperature range. In the step (3), the dispersion liquid is placed in a temperature range of Tg ± 10 ° C. at 0.70 ° C./min or less (more preferably 0.40 ° C./min or less, still more preferably 0.20 ° C./min or less). It may be cooled at the cooling rate.

The ratio of the cooling rate 2 to the cooling rate 1 is preferably 0.00 or more and 0.05 or less, and more preferably 0.00 or more and 0.02 or less. In this range, the crystalline material that is compatible with the binder resin during cooling in step (2) forms a very large number of crystal nuclei in step (3), so that the amount of dispersion of the crystalline material increases and the amount of dispersion of the crystalline material increases. The degree of crystallinity is further improved. Therefore, the low temperature fixability and the storage stability are very good.
In order to control the cooling rate 2 and the ratio of the cooling rate 2 to the cooling rate 1 within a predetermined range, it is important to control the temperature of the water-based medium that has undergone the step (2) so as to satisfy a predetermined temperature range. Is.

As described above, when the toner is rapidly cooled at a cooling rate of 5.00 ° C./min or higher, a large number of fine domains of the crystalline material can be dispersed inside the toner. In addition, it becomes easy to control the number average value of the major axis of the microdomain of the crystalline material within a specific range. By increasing the cooling rate, it is possible to reduce the number average value of the major axis of the microdomain.
Since the fine domains of the crystalline material can be formed inside the toner particles by the above-mentioned cooling step, the abundance of the crystalline material on the surface of the toner particles tends to be significantly reduced. Therefore, it is possible to control the charge decay rate at 25 ° C. to a low level. Further, since it becomes easy to control the number average value of the major axis of the minute domain within a range suitable for the present invention, it becomes possible to control the charge decay rate of the toner after heating to be high. As described above, the above-mentioned cooling step makes it possible to simultaneously control the charge decay rate at 25 ° C. and the charge decay rate after heating within a desired range, and it is easy to achieve both low-temperature fixability and suppression of sticking at the same time. Become.

When the crystalline material contains a monoester compound and a hydrocarbon wax and is produced by the above-mentioned production method, the monoester compound forms a microdomain, and the hydrocarbon wax tends to form a large domain. In this case, since the hydrocarbon wax forms a large domain near the center of the toner particles, the minute domains are likely to be locally present near the surface of the toner particles.

The toner particles that have undergone the above steps (1) to (3) can be filtered, washed, and dried by a known method.
The obtained toner particles may be used as they are as toner. If necessary, an external additive or the like may be added and mixed and adhered to the surface to form toner. A known method such as Henschel mixer can be used for mixing the external additives.
It is also possible to remove coarse powder and fine powder by inserting a classification process in the manufacturing process (before mixing the external additive).
As the external additive, inorganic fine particles having an average number of primary particles of 4 nm or more and 80 nm or less (more preferably 6 nm or more and 40 nm or less) are preferable.
The average particle size of the number of primary particles of the inorganic fine particles may be determined by using a photograph of the toner taken magnified by a scanning electron microscope.

Inorganic fine particles are added to improve the fluidity of the toner and make the chargeability of the toner uniform. By hydrophobizing the inorganic fine particles, the toner charge amount can be adjusted and the environmental stability can be improved. It is also possible to give it. Examples of the treatment agent used for the hydrophobization treatment include treatment agents such as silicone varnish, various modified silicone varnishes, silicone oils, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds. .. These may be used alone or in combination of two or more.
Examples of the inorganic fine particles include silica fine particles, titanium oxide fine particles, and alumina fine particles. The silica fine particles include, for example, both dry silica fine particles produced by vapor phase oxidation of a silicon halide, so-called dry silica fine particles or fumed silica, and so-called wet silica fine particles produced from water glass or the like. Can be used.
Further, in the dry silica fine particles, it is possible to obtain composite fine particles of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with the silicon halogen compound in the manufacturing process. Including them.
The amount of the inorganic fine particles added is preferably 0.1 part by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

Next, an example of an image forming apparatus capable of suitably using toner will be specifically described with reference to FIG. In FIG. 3, 100 is an electrostatic latent image carrier (hereinafter, also referred to as a photoconductor), and a developer having a charging member (charging roller) 117, a toner carrier 102, a developing blade 103, and a stirring member 141 around the electrostatic carrier. 140, a transfer member (transfer charging roller) 114, a cleaner container 116, a fuser 126, a pickup roller 124, a transport belt 125, and the like are provided.
The photoconductor 100 is charged to, for example, −600 V by the charging roller 117 (applied voltage is, for example, AC voltage 1.85 kVpp, DC voltage −620 Vdc). Then, the photoconductor 100 is exposed by irradiating the photoconductor 100 with the laser 123 by the laser generator 121, and an electrostatic latent image corresponding to the target image is formed. The electrostatic latent image on the photoconductor 100 is developed by the developer 140 with one component toner to obtain a toner image. The toner image is transferred onto the transfer material by the transfer charging roller 114 that is in contact with the photoconductor via the transfer material. The transfer material on which the toner image is placed is carried to the fixing device 126 by a transport belt 125 or the like and fixed on the transfer material. Further, the toner partially left on the photoconductor is cleaned by the cleaner container 116.
Although the image forming apparatus for magnetic one-component jumping development is shown here, it may be used for either jumping development or contact development.

Next, a method for measuring each physical property according to the present invention will be described.
<Measuring method of toner weight average particle size (D4)>
The weight average particle size (D4) of the toner is calculated as follows. As the measuring device, a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter) equipped with a 100 μm aperture tube by the pore electric resistance method is used. For the setting of measurement conditions and the analysis of measurement data, the attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) is used. The measurement is performed with 25,000 effective measurement channels.
As the electrolytic aqueous solution used for the measurement, one in which special grade sodium chloride is dissolved in ion-exchanged water so that the concentration becomes about 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter) can be used.
Before performing measurement and analysis, set the dedicated software as follows.
On the "Change standard measurement method (SOM)" screen of the dedicated software, set the total count number in the control mode to 50,000 particles, measure once, and set the Kd value to "standard particles 10.0 μm" (Beckman Coulter). The value obtained by using (manufactured by) is set. By pressing the "threshold / noise level measurement button", the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, and the electrolyte to ISOTON II, and check "Flash of aperture tube after measurement".
On the "Pulse to particle size conversion setting" screen of the dedicated software, set the bin spacing to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range from 2 μm to 60 μm.

The specific measurement method is as follows.
(1) Put about 200 mL of the electrolytic aqueous solution in a glass 250 mL round bottom beaker dedicated to Multisizer 3, set it on a sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube are removed by the "flash of the aperture tube" function of the dedicated software.
(2) Put about 30 mL of the electrolytic aqueous solution in a 100 mL flat-bottomed beaker made of glass. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a pH 7 precision measuring instrument consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted about 3 times by mass with ion-exchanged water, and about 0.3 mL of the diluted solution is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with their phases shifted by 180 degrees, and an ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios) with an electrical output of 120 W is prepared. About 3.3 L of ion-exchanged water is put into the water tank of the ultrasonic disperser, and about 2 mL of contaminone N is added to this water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the electrolytic solution in the beaker is maximized.
(5) With the electrolytic aqueous solution in the beaker of (4) being irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion processing is continued for another 60 seconds. For ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10 ° C. or higher and 40 ° C. or lower.
(6) Using a pipette, the electrolytic aqueous solution of (5) in which toner is dispersed is dropped onto the round bottom beaker of (1) installed in the sample stand, and the measured concentration is adjusted to about 5%. .. Then, the measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed by the dedicated software attached to the device, and the weight average particle size (D4) is calculated. The "average diameter" of the "analysis / volume statistical value (arithmetic mean)" screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Measurement of toner charge>
The amount of charge of the toner was measured with respect to 1.0 g of the toner by a magnetic carrier (Standard Carrier For q / m Measurement N-01 manufactured by Nippon Imaging Co., Ltd.) 19.
A mixture of 0 g is left to stand in an environment of 33 ° C. and 80% for 24 hours, shaken with a YS-8D type manufactured by YAYOI at 150 rpm for 1 minute, and measured as follows.
FIG. 4 shows an example of a charge amount measuring device.
First, about 0.4 g of a mixture of a pigment and a carrier whose charge amount is to be measured is placed in a metal measuring container 102 having a 500 mesh screen 103 on the bottom, and a metal lid 104 is attached. The weight of the entire measuring container 102 at this time is weighed, and the value is defined as W1 (g).
Next, in the suction machine 101 (the portion in contact with the measuring container 102 is at least an insulator), suction is performed from the suction port, and the air volume control valve 106 is adjusted to set the pressure of the vacuum gauge 105 to 250 mmAq. In this state, suction is sufficiently performed, preferably for 2 minutes, to remove the toner by suction. The potential of the electrometer 109 at this time is V (volt). Here, 108 is a capacitor, and the capacitance is C (μF).
Next, the weight of the entire measuring container after suction is weighed and used as W2 (g). The charge amount (mC / kg) of this pigment is calculated by the following formula using the values measured above.
Toner charge amount (μC / g) = (C × V) / (W1-W2)

<Measurement method of toner charge decay rate>
Toner charge decay rate is calculated using the corona charging device KTK-2001 attached to the thermal stimulation current measurement system (trade name: TS-POLAR, manufactured by Rigaku Co., Ltd.) and the surface electrometer Model347 (manufactured by Trek Co., Ltd.). Do as follows. Here, the case of negatively charged toner will be described. In the case of positively chargeable toner, all the polarity settings may be changed to reverse polarity.
(1) Set of sample holder (1-1) Set the sample holder attached to the thermal stimulation current measurement system on the sample part of the main body, and close the holder guard.
(1-2) A probe of the surface electrometer is installed in the surface electrometer installation part of the corona charging device.
(1-3) Turn on the power of the surface electrometer, move the sample holder to the lower part of the surface electrometer, and turn the Zero Adjust knob of the surface electrometer to adjust the surface potential to 0.0V. At this time, the distance between the sample holder and the surface electrometer is set to 3 mm.
(2) Sample set (2-1) Weigh 700 mg of toner in a sample pan (made of aluminum) and place it on the sample holder.
(2-2) Rotate the turntable, move the sample to the bottom of the corona electrode, and close the cover.
(3) Charging (3-1) Insert the high-voltage cable into the- (minus) side of the polarity switching connector on both the grid side and corona side (insert the dummy connector on the + (plus) side).
(3-2) Set the polarity changeover switch on the grid side and corona side to the- (minus) side, and turn on the power of the corona charging device.
(3-3) Press the high voltage ON switch on the grid side and turn the grid voltage adjustment dial to set the grid side voltage to 1 kv.
(3-4) Press the high voltage ON switch on the corona side and turn the corona voltage adjustment dial to set the corona side voltage to 20 kv.
(3-5) In this state, the sample is charged for 30 seconds.
(4) Potential measurement (4-1) Rotate the turntable to move the sample to the bottom of the probe of the surface electrometer. This time point is taken as the measurement start time.
(4-2) In this state, the surface potential is measured for 180 seconds. The surface potential after 5 seconds from the start of measurement is set as the initial surface potential V0, and the charge decay rate is calculated from the surface potential transition from 5 _seconds to 95 seconds according to the following formula.
ln (V _t / V ₀ ) =-αt ^(1/2)
(In the above equation, V indicates the surface potential (V), V _t indicates the surface potential (V) after t seconds, V ₀ indicates the initial surface potential (V), and α indicates charge decay. The velocity (1 / s ^(1/2) ) is indicated, and t indicates the decay time (seconds).)
When measuring a sample heated at 80 ° C. for 1 minute, in (2-1) above, put the sample pan weighing the sample into a constant temperature bath whose temperature has been adjusted to 80 ° C., take it out after 1 minute, and then put it in the sample holder. Put it on.

<Measurement method of glass transition temperature Tg (° C) of toner, toner particles and resin>
The glass transition temperature Tg (° C.) of the toner, the toner particles and the resin is measured according to ASTM D3418-82 using a differential scanning calorimeter "Q1000" (manufactured by TA Instruments).
The melting point of indium and zinc is used for temperature correction of the device detector, and the heat of fusion of indium is used for the correction of calorific value.
Specifically, 10 mg of the sample is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference. The temperature rise rate is 10 ° C./ Measure in min.
In this temperature raising process, a specific heat change is obtained in the range of 40 ° C. or higher and 100 ° C. or lower. The glass transition temperature is the temperature at the intersection of the straight line at the same distance in the vertical axis direction from the straight line extending the baseline before and after the specific heat change at this time and the curve of the stepwise change part of the glass transition. Let it be Tg (° C.).

<Measurement of crystallization temperature Tc (° C) and melting point Tm (° C) of crystalline material>
The crystallization temperature Tc (° C.) and the melting point Tm (° C.) of the crystalline material are measured according to ASTM D3418-82 using a differential scanning calorimeter "Q1000" (manufactured by TA Instruments).
The melting point of indium and zinc is used for temperature correction of the device detector, and the heat of fusion of indium is used for the correction of calorific value.
Specifically, 10 mg of a sample is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature rise rate is 10 within a measurement range of 30 ° C. or higher and 200 ° C. or lower. Measure at ° C / min.
In the measurement, the temperature was once raised to 200 ° C. at a temperature rising rate of 10 ° C./min, then lowered to 30 ° C. at a temperature lowering rate of 10 ° C./min, and then raised again at a temperature rising rate of 10 ° C./min. Do warm. The peak temperature of the maximum endothermic peak in the specific heat change curve measured at 30 ° C. or higher and 200 ° C. or lower in the second temperature raising process is defined as the melting point Tm (° C.) of the crystalline material.
Further, the temperature at which the minimum endothermic peak of the specific heat change curve measured at 30 ° C. or higher and 200 ° C. or lower in the temperature lowering process is defined as the crystallization temperature Tc (° C.) of the crystalline material.

<Measuring method of the number average value of the major axis of the domain of crystalline material>
The number average value of the major axis of the domain of the crystalline material means the number average diameter obtained from the major axis of the domain of the crystalline material based on the cross-sectional image of the toner particles observed by the transmission electron microscope (TEM). do.
The cross section of the toner particles observed with a transmission electron microscope (TEM) is prepared as follows.
Using an osmium plasma coater (filgen, OPC80T), an Os film (5 nm) and a naphthalene film (20 nm) were applied to the toner as a protective film, and the toner was embedded in a photocurable resin D800 (JEOL Ltd.) and then ultra-supercharged. A toner particle cross section having a film thickness of 60 nm (or 70 nm) is produced at a cutting speed of 1 mm / s by an ultrasonic ultramicrotome (Leica, UC7).
The obtained cross section was subjected to RuO ₄ gas 5 using a vacuum electron staining device (filgen, VSC4R1H).
Staining was performed in a 00 Pa atmosphere for 15 minutes, and STEM observation was performed using the STEM function of TEM (JEOL, JEM2800). The STEM probe size is 1 nm and the image size is 1024 x 1024 pixels.
For the obtained image, the major axis of the domain is obtained using the image processing software "Image-Pro Plus (manufactured by Media Cybernetics)".
When the cross section of the toner particles is stained with ruthenium, the crystalline material is not stained, so that the domain of the crystalline material looks black when observed by TEM, and the domain can be identified. In calculating the domain diameter, observe the cross section of 100 toner particles. All domains with a major axis of 10 nm or more and 1000 nm or less are measured, and the number average value is calculated. The presence or absence of the formation of microdomains in the crystalline material is determined, and the obtained number average value is used as the number average value of the major axis of the microdomains in the crystalline material.

<Measuring method of measuring the amount (25% ratio) of the minute domain of the crystalline material present within 25% of the distance between the contour and the center of gravity of the cross section from the contour of the toner particle cross section>
The 25% ratio is the ratio (number%) of the minute domains of the crystalline material existing in the region within 25% of the distance between the contour and the center of gravity of the cross section from the contour of the toner particle cross section.
The calculation method of the 25% ratio is as follows.
In the above TEM image, the contour of the cross section of the toner particles is obtained by the method described later. It is assumed that the cross section of the toner particles to be observed exhibits a major axis R (μm) satisfying the relationship of 0.9 ≦ R / D4 ≦ 1.1 with respect to the weight average particle size (D4) of the toner. The contour of the cross section of the toner particles shall be along the surface of the toner particles observed in the above TEM image. A line is drawn from the center of gravity of the toner particle cross section to a point on the contour of the toner particle cross section. On the line, the position of 25% of the distance between the contour and the center of gravity of the cross section is specified from the contour.
Then, this operation is performed for one round of the contour of the toner particle cross section, and a boundary line of 25% of the distance between the contour and the center of gravity of the cross section is clearly indicated from the contour of the toner particle cross section (FIG. 3).
Based on the TEM image in which the 25% boundary line is clearly shown, the number of minute domains (domains having a major axis of 10 nm or more and 1000 nm or less) in the cross section of one toner particle is measured (hereinafter referred to as A). do. Further, in the cross section of one toner particle, a minute domain (major axis of 10 nm or more and 1000 nm or less) of a crystalline material existing in a region within 25% of the distance between the contour and the center of gravity of the cross section from the contour of the toner particle cross section. The number of domains (hereinafter referred to as B) is measured.
The minute domain of the crystalline material existing on the 25% boundary line is measured as "B".
Next, the 25% ratio in the cross section of one toner particle is calculated by the following formula.
25% ratio in cross section of one toner particle = {"B" / "A"} x 100 (%)
This is done for the cross sections of 100 toner particles, and the arithmetic mean value is taken as a 25% ratio.

<Calculation method of the presence index near the surface of a magnetic material>
The near-surface presence index of the magnetic material is the number of magnetic materials existing near the surface of the magnetic toner particles, and indicates the number per 1 μm ² of the surface area.
The surface proximity index is calculated using an image obtained by observing a reflected electron image of a field emission scanning electron microscope S-4800 (Hitachi High-Technologies Corporation).
Inject liquid nitrogen into the anti-contamination trap attached to the housing of S-4800 until it overflows, and leave it for 30 minutes. Start the "PC-SEM" of S-4800 and perform flushing (cleaning of the FE chip which is an electron source). Click the acceleration voltage display part of the control panel on the screen and press the [Flushing] button to open the flushing execution dialog. Confirm that the flushing intensity is 2, and execute. Confirm that the emission current due to flushing is 20 to 40 μA. Insert the sample holder into the sample chamber of the S-4800 housing. Press [Origin] on the control panel to move the sample holder to the observation position.
Click the acceleration voltage display to open the HV setting dialog, and set the acceleration voltage to [5.0 kV] and the emission current to [20 μA]. In the [Basic] tab of the operation panel, set the signal selection to [SE], select [Top (U)] and [+ BSE] for the SE detector, and select [+ BSE] in the selection box to the right of [+ BSE]. L. A. 100] is selected to set the mode for observing with a backscattered electron image. Similarly, in the [Basic] tab of the operation panel, set the probe current of the electro-optical system condition block to [Normal], the focal mode to [UHR], and the WD to [3.0 mm]. Press the [ON] button on the acceleration voltage display of the control panel to apply the acceleration voltage.
Under the above observation conditions, the magnetic material glows white and is observed. Focus on the glowing magnetic material and save the SEM image. Using the image analysis software image-J, this image is detected by detecting the number of magnetic materials as the peak of luminance, and the number of magnetic materials per unit area is calculated. The above analysis was performed on 100 toner particles, and the number average value was taken as the surface neighborhood existence index.

Hereinafter, the present invention will be described in more detail with reference to Production Examples and Examples, but these are not limited to the present invention. The number of copies in the following formulations is based on mass unless otherwise specified.

<Synthesis of crystalline material 1>
To a reaction vessel equipped with a thermometer, a nitrogen inlet tube, a stirrer, a Dean-Stark trap and a Dimroth condenser, 100 parts of behenyl alcohol as alcohol monomer 1 and 80 parts of stearic acid as carboxylic acid monomer 1 are added, and esterification is performed at 200 ° C. for 15 hours. An esterification reaction was carried out. To the obtained ester compound, 20 parts of toluene and 25 parts of isopropanol were added, 190 parts of a 10 mass% potassium hydroxide aqueous solution in an amount corresponding to 1.5 times the acid value of the ester compound was added, and the mixture was stirred at 70 ° C. for 4 hours. .. Then, the aqueous phase part was removed.
Further, 20 parts of ion-exchanged water was added and stirred at 70 ° C. for 1 hour, and then the aqueous phase part was removed for washing. The above washing step was repeated until the pH of the removed aqueous phase became neutral. Then, the solvent was removed by reducing the pressure at 200 ° C. and 1 kPa to obtain a crystalline material 1 which is behenyl stearate, which is an ester compound of behenyl alcohol and stearic acid, which is the final product. When the crystalline material 1 was analyzed, the melting point was 68 ° C. Table 1 shows the physical characteristics of the obtained crystalline material 1.

<Manufacturing of crystalline materials 2 to 7>
In the production of the crystalline material 1, the alcohol monomer 1 and the carboxylic acid monomer 1 were changed as shown in Table 1 and the reaction time and temperature were adjusted to obtain desired physical properties. I got ~ 7. The physical characteristics of the obtained crystalline material are added to Table 1. Since the crystalline material 5 is sebacic acid dibehenate, it has 54 carbon atoms. Further, since the crystalline material 6 is pentaerythritol tetrabehenate, it has 93 carbon atoms.

<Production example of magnetic iron oxide>
4.0 mol in 50 liters of the first iron sulfate aqueous solution containing 2.0 mol / L of Fe ²⁺
55 liters of / L sodium hydroxide aqueous solution was mixed and stirred to obtain a ferrous salt aqueous solution containing a ferrous hydroxide colloid. This aqueous solution was kept at 85 ° C. and an oxidation reaction was carried out while blowing air at 20 L / min to obtain a slurry containing core particles.
The obtained slurry was filtered and washed with a filter press, and then the core particles were redispersed in water and reslurryed. To this reslurry liquid, sodium silicate having 0.20% by mass in terms of silicon per 100 parts of core particles is added, the pH of the slurry liquid is adjusted to 6.0, and stirring is performed to perform magnetic oxidation having a silicon-rich surface. Obtained iron particles. The obtained slurry was filtered and washed with a filter press, and further reslurryed with ion-exchanged water.
500 parts (10% by mass with respect to magnetic iron oxide) of the ion exchange resin SK110 (manufactured by Mitsubishi Chemical Corporation) was added to this reslurry liquid (solid content 50 g / L), and the mixture was stirred for 2 hours to perform ion exchange. Then, the ion exchange resin was filtered off with a mesh, filtered and washed with a filter press, dried and crushed to obtain magnetic iron oxide having an average number diameter of 0.23 μm.

<Manufacturing of silane compounds>
30 parts of iso-butyltrimethoxysilane was added dropwise to 70 parts of ion-exchanged water with stirring. Then, this aqueous solution was kept at a pH of 5.5 and a temperature of 55 ° C., and hydrolyzed by dispersing at a peripheral speed of 0.46 m / s for 120 minutes using a disper blade. Then, the pH of the aqueous solution was set to 7.0, and the solution was cooled to 10 ° C. to stop the hydrolysis reaction. In this way, an aqueous solution containing a silane compound was obtained.

<Manufacturing of magnetic material 1>
100 parts of magnetic iron oxide was placed in a high-speed mixer (LFS-2 type manufactured by Fukae Pautech Co., Ltd.), and 8.0 parts of an aqueous solution containing a silane compound was added dropwise over 2 minutes while stirring at a rotation speed of 2000 rpm. Then, it was mixed and stirred for 5 minutes. Then, in order to enhance the stickiness of the silane compound, the mixture was dried at 40 ° C. for 1 hour to reduce the water content, and then the mixture was dried at 110 ° C. for 3 hours to allow the condensation reaction of the silane compound to proceed. Then, it was crushed and passed through a sieve having an opening of 100 μm to obtain a magnetic substance 1.

<Manufacturing of toner 1>
450 parts of 0.1 mol / L-Na ₃ PO ₄ aqueous solution was added to 720 parts of ion-exchanged water and heated to 60 ° C., and then 67.7 parts of 1.0 mol / L-CaCl ₂ aqueous solution was added. , An aqueous medium containing a dispersion stabilizer was obtained.
・ Styrene 76.0 parts ・ n-butyl acrylate 24.0 parts ・ Divinylbenzene 0.2 parts ・ Monoazo dye iron complex (T-77: manufactured by Hodogaya Chemical Co., Ltd.) 1.5 parts ・ Magnetic material 1 120.0 parts 3.0 parts of amorphous saturated polyester resin (Atypical saturated polyester obtained by condensation reaction of ethylene oxide (2 mol) adduct of bisphenol A and propylene oxide (3 mol) adduct of bisphenol A with terephthalic acid. Resin; Mw = 9500, acid value = 2.2 mgKOH / g, glass transition temperature = 68 ° C.)
The above formulation was uniformly dispersed and mixed using an attritor (manufactured by Mitsui Miike Machinery Co., Ltd.) to obtain a monomer composition. This monomer composition was heated to 63 ° C., and 25 parts of the crystalline material 1 shown in Table 1 was used as the crystalline material (1) and paraffin wax (melting point 77 ° C., Tc 75 ° C.) which was a hydrocarbon wax. ) 11 parts were mixed as the crystalline material (2) and dissolved.
The above-mentioned monomer composition is put into the above-mentioned aqueous medium, and the motor of TK homomixer (manufactured by Tokushu Kikai Kogyo Co., Ltd.) is modified at 60 ° C. and N ₂ atmosphere at 24000 rpm (dispersion step: condition 1). ) Was stirred for 10 minutes to granulate the suspension. After that, 8.0 parts of the polymerization initiator t-butylperoxypivalate was added while stirring with a paddle stirring blade, and the temperature was raised to 70 ° C. 4
Time reacted.
After completion of the reaction, the suspension was heated to 100 ° C. and held for 2 hours. Then, as a cooling step, water at 0 ° C. was added to the suspension, the suspension was cooled from 100 ° C. to 50 ° C. at a rate of 200 ° C./min, and then held at 50 ° C. for 6 hours. Then, it was naturally cooled to 25 ° C. at room temperature to cool it. The cooling rate at that time was 1 ° C./min. Then, hydrochloric acid was added to the suspension and washed thoroughly to dissolve the dispersion stabilizer, which was then filtered and dried to obtain toner particles 1.
Further, 100 parts of toner particles 1 and 0.8 parts of hydrophobic silica fine particles having a BET value of 300 m ² / g and an average particle size of 8 nm are added to Mitsui Henshell Mixer (Mitsui Miike Machinery Co., Ltd.). Toner 1 was obtained by mixing with (manufactured by).
When the toner 1 was analyzed, the main component of the binder resin in the toner 1 was styrene acrylic resin. The charge decay rate of the toner 1 at 25 ° C. is −0.0010 (1 / s ^(1/2) ), and the charge decay rate after heating is −0.0070 (1 / s ^(1/2) ). rice field. The charge amount of the toner 1 was −45 μC / g. Table 2 shows the production conditions of the toner 1 and the analysis results.

<Manufacturing of toners 2 to 12 and comparative toners 1 to 5>
As shown in Table 2, the toners 2 to 12 are the same as in the production of the toner 1, except that the conditions of the crystalline material (1), the crystalline material (2), the pigment, the granulation step and the cooling step are changed. Comparative toners 1 to 5 were manufactured.
The carbon black used was made by Mitsubishi Chemical (trade name: # 25B). In the cooling step, the temperature at which the cooling step was started was set to 100 ° C., and the temperature at which the cooling step was stopped was set to be the same as the holding temperature shown in Table 2. Retention time indicates the time controlled to keep the temperature of the suspension constant at the retention temperature. The cooling rate was adjusted to the rate shown in Table 2 by controlling the rate at which water at 0 ° C. was added to the suspension.
In the cooling step of the comparative toner 1, the suspension at 100 ° C. was naturally cooled at room temperature of 25 ° C., and cooled to 25 ° C. without holding at 50 ° C. The cooling rate at that time was 3 ° C./min. Condition 2 in the dispersion step is T.I. K. It is a condition for granulating the suspension by operating at a rotation speed of 12000 rpm without modifying the homixer.
Table 2 shows the production conditions and analysis results of the obtained toners 2 to 12 and the comparative toners 1 to 5.

<Manufacturing of comparative toner 6>
Bound resin 1: 100 parts (composition: styrene acrylic copolymer, Mw = 15000)
-Wax: 3 parts (paraffin wax (melting point 77 ° C, Tc 75 ° C))
-Magnetic material: 95 parts (composition: Fe ₃ O ₄ , shape: spherical, number of primary particles Average particle diameter: 0.21 μm, magnetic properties at 795.8 kA / m; Hc: 5.5 kA / m, σs: 84 .0Am ² / kg, σr: 6.4Am ² / kg)
-Charge control agent T-77 (Hodogaya Chemical Co., Ltd.): 1 part-Crystallinic material 4: 7 parts The above raw materials were premixed with Henschel Mixer FM10C (Mitsui Miike Machinery Co., Ltd.). Further, a twin-screw kneading extruder (PCM-30: manufactured by Ikegai Iron Works Co., Ltd.) set at a rotation speed of 200 rpm was used to adjust the set temperature so that the direct temperature near the outlet of the kneaded material was 155 ° C., and kneaded.
The obtained melt-kneaded product was naturally cooled at room temperature, and the cooled melt-kneaded product was roughly pulverized with a cutter mill. The temperature after cooling was 25 ° C., and the cooling rate at that time was 50 ° C./min.
Then, the obtained coarsely pulverized product was finely pulverized using a turbo mill T-250 (manufactured by Turbo Industries, Ltd.) with a feed amount of 20 kg / hr and an air temperature adjusted to 38 ° C. The obtained finely pulverized material was classified using a multi-division classifier utilizing the Coanda effect to obtain comparative toner particles 6 having a weight average particle size (D4) of 7.9 μm.
Further, 100 parts of toner particles 1 and 0.8 parts of hydrophobic silica fine particles having a BET value of 300 m ² / g and an average particle size of 8 nm are added to Mitsui Henshell Mixer (Mitsui Miike Machinery Co., Ltd.). The comparison toner 6 was obtained by mixing with (manufactured by). Table 2 shows the physical characteristics of the obtained comparative toner 6.

<Manufacturing of comparative toner 7>
(Manufacturing of Crystalline Material Dispersion Liquid 1)
Crystalline material 4:10 parts Ethyl acetate: 67.5 parts Ion-exchanged water: 200.0 parts or more were mixed, and 3 mm zirconia with a 60% volume ratio was added to make paint conditioner NO. Using a type 5400 (manufactured by RED DEVIL, USA), the mixture was dispersed until the weight average particle size (D4) became 400 nm to obtain a crystalline material dispersion liquid 1.
(Manufacturing of Crystalline Material Dispersion Liquid 2)
Paraffin wax (melting point 77 ° C.): 3 parts Ethyl acetate: 67.5 parts Ion-exchanged water: 200.0 parts or more was mixed, and 3 mm zirconia with a 60% volume ratio was added to make paint conditioner NO. Using a type 5400 (manufactured by RED DEVIL, USA), the mixture was dispersed until the weight average particle size (D4) became 400 nm to obtain a crystalline material dispersion liquid 2.

(Synthesis of amorphous resin 1)
The following raw materials were charged into a heat-dried two-necked flask while introducing nitrogen.
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane
30 parts Polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane
34 parts terephthalic acid 30 parts fumaric acid 6.0 parts dibutyltin oxide 0.1 part After replacing the inside of the system with nitrogen by a reduced pressure operation, stirring was performed at 215 ° C. for 5 hours. Then, the temperature is gradually raised to 230 ° C. under reduced pressure while continuing stirring, and the mixture is held for another 2 hours. The amorphous resin 1 which is an amorphous polyester was obtained by air-cooling when it became a viscous state and stopping the reaction.
(Manufacturing of resin particle dispersion liquid 1)
50.0 parts of the amorphous resin 1 is dissolved in 200.0 parts of ethyl acetate, and 3.0 parts of an anionic surfactant (sodium dodecylbenzene sulfonate) is added together with 200.0 parts of ion-exchanged water. The mixture was heated to 40 ° C. and stirred at 8000 rpm for 10 minutes using an emulsifier (Ultratalax T-50 manufactured by IKA), and then ethyl acetate was volatilized and removed to obtain a resin particle dispersion liquid 1. ..

(Preparation of colorant dispersion 1)
-Coloring agent (phthalocyanine pigment 15: 3 type, "CI Pigment Blue" manufactured by Clariant Japan Co., Ltd.) 8.0 parts-Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku): 5.0 parts-Ion Exchange water: 200.0 parts by mass Put the above material into a heat-resistant glass container, and apply paint conditioner NO. Disperse with a 5400 type (manufactured by RED DEVIL, USA) for 5 hours, remove the glass beads with a nylon mesh, and obtain a colorant dispersion 1 having a volume-based median diameter (D50) of 220 nm and a solid content of 20% by mass. rice field.

(Manufacturing process of comparative toner 7)
Colorant dispersion 1: 25.0 parts Crystalline material dispersion 1: 30.0 parts Crystalline material dispersion 2: 30.0 parts 10 mass% polyaluminum chloride aqueous solution 1.5 parts or more in a round stainless steel flask After mixing in the mixture and mixing and dispersing with Ultratarax T50 manufactured by IKA, the mixture was held at 45 ° C. for 60 minutes with stirring (aggregation step). Then, the resin particle dispersion 1 (50 parts) was slowly added, the pH in the system was adjusted to 6 with a 0.5 mol / L sodium hydroxide aqueous solution, the stainless steel flask was sealed, and a magnetic force seal was used. The mixture was heated to 96 ° C. while continuing stirring. Until the temperature was raised, an aqueous solution of sodium hydroxide was added as appropriate so that the pH did not drop below 5.5. Then, it was held at 96 ° C. for 5 hours (fusion step).
Then, after cooling, filtering, and thoroughly washing with ion-exchanged water, solid-liquid separation was performed by Nucci-type suction filtration. This was further redispersed in 3 L of ion-exchanged water, and the mixture was stirred and washed at 300 rpm for 15 minutes. This was repeated 5 times, and when the pH of the filtrate reached 7.0, solid-liquid separation was performed using a filter paper by Nucci-type suction filtration. Then, vacuum drying was continued for 12 hours to obtain comparative toner particles 7.
After that, 100 parts of the comparative toner particles 12 and 0.8 parts of hydrophobic silica fine particles having a BET value of 300 m ² / g and a primary particle size of 8 nm were added to Mitsui Henchel Mixer (manufactured by Mitsui Miike Machinery Co., Ltd.). To obtain a comparative toner 7. Table 2 shows the physical characteristics of the obtained comparative toner 7.

<Manufacturing of comparative toner 8>
(Toner core manufacturing process)
Polyester resin A (acrystalline saturated polyester resin obtained by a condensation reaction between an ethylene oxide (2 mol) adduct of bisphenol A and a propylene oxide (3 mol) adduct of bisphenol A and terephthalic acid; hydroxyl value (OHV value) = 20 mgKOH / g, acid value (AV value) = 40 mgKOH / g, softening point (Tm) = 90 ° C., glass transition point (Tg) = 49 ° C.) Clarant Japan Co., Ltd. "CI Pigment Blue") 5 parts, 5 parts of crystalline material 6
The parts were mixed and mixed at 2400 rpm using a Mitsui Henschel Mixer (manufactured by Mitsui Miike Machinery Co., Ltd.).
The obtained mixture was kneaded with a twin-screw extruder (“PCM-30” manufactured by Ikegai Corp.), and the chips were pulverized with a mechanical crusher (“Turbo Mill T250” manufactured by Freund Turbo Co., Ltd.). Then, the toner was obtained by classifying with a classifying machine (“Elbow Jet EJ-LABO type” manufactured by Nittetsu Mining Co., Ltd.).

(Shell layer forming process)
A 1 liter three-necked flask was set in a water bath at 30 ° C., and 300 mL of ion-exchanged water was adjusted to pH 4 with hydrochloric acid. 2 mL of an aqueous solution of hexamethylol melamine initial polymer ("Milben (registered trademark) Resin SM-607" manufactured by Showa Denko KK, solid content concentration 80% by mass) was added to this solution and dissolved to form a 6 nm film. .. 300 g of the toner core obtained in the step of producing the toner core was added to this aqueous solution, and the mixture was sufficiently stirred. Further, 300 mL of ion-exchanged water was added, the temperature was raised at a rate of 1 ° C./min with stirring, and the temperature was maintained at 70 ° C. for 2 hours. After that, it was naturally cooled to 25 ° C., and the cooling rate at that time was 3 ° C./min. Then, it was neutralized to pH 7, filtered and washed, and dried to obtain toner matrix particles.
(External process)
After the above drying, the toner matrix particles were externally treated. Specifically, 100 parts of toner matrix particles, 0.5 parts of dry silica (“AEROSIL® 200” manufactured by Nippon Aerosil Co., Ltd.), and Mitsui Henshell Mixer (manufactured by Mitsui Miike Machinery Co., Ltd.) as an external additive. By mixing the toner at a rotation speed of 3500 rpm for 5 minutes, dry silica was adhered to the surface of the toner matrix particles to obtain a comparative toner 8. When the comparative toner 8 was observed by TEM, no microdomains of a crystalline material having a size of 1 μm or less were observed. The physical characteristics are shown in Table 2.

<Manufacturing of comparative toner 9>
73 parts of styrene and 27 parts of n-butyl acrylate as monovinyl monomer, 7 parts of carbon black (manufactured by Mitsubishi Chemical, trade name: # 25B) as a black colorant, 0.75 part of divinylbenzene as a crosslinkable polymerizable monomer Part, styrene / acrylic resin (manufactured by Fujikura Kasei Co., Ltd., trade name: FCA-592P) 0.38 part as charge control agent, tetraethylthiuram disulfide 1 part as molecular weight adjuster, and polymethacrylic acid ester macromonomer as macromonomer ( 0.25 parts (trade name: AA6, Tg = 94 ° C.) manufactured by Toa Synthetic Chemical Industry Co., Ltd. were stirred and mixed with a normal stirring device, and then uniformly dispersed by a media type disperser.
Here, behenyl stearate (crystalline material 1) and behenyl palmitate (crystalline material 7) are added in a ratio of (behenyl stearate): (behenyl palmitate) = 98.0% by mass: 2.0% by mass. 20 parts of the softening agent A (melting point: 70 ° C.) obtained by mixing in the above was added, mixed and dissolved to obtain a polymerizable monomer composition. All preparations of the polymerizable monomer composition were carried out at room temperature.
On the other hand, in a stirring tank, at room temperature, an aqueous solution in which 7.4 parts of magnesium chloride is dissolved in 250 parts of ion-exchanged water and 4.1 parts of sodium hydroxide in 50 parts of ion-exchanged water are dissolved under stirring. Gradually added to prepare a magnesium hydroxide colloidal dispersion (3.0 parts of magnesium hydroxide).
The above-mentioned polymerizable monomer composition is put into the magnesium hydroxide colloidal dispersion obtained above at room temperature, stirred until the droplets are stabilized, and there is t-butylperoxy- as a polymerization initiator. After adding 5 parts of 2-ethylhexanoate (manufactured by Nichiyu Co., Ltd., trade name: Perbutyl O), a rotation speed of 15,000 rpm is used using an in-line emulsion disperser (manufactured by Pacific Kiko Co., Ltd., trade name: Milder). A droplet of the polymerizable monomer composition was formed by stirring with high shear.
The magnesium hydroxide colloidal dispersion in which the droplets of the polymerizable monomer composition are dispersed is charged into a reactor equipped with a stirring blade, and the temperature is raised to 89 ° C. to control the temperature to be constant. , Polymerization reaction was carried out. Next, when the polymerization conversion rate reached 98%, the temperature inside the system was cooled to 75 ° C., and 15 minutes after reaching 75 ° C., 3 parts of methyl methacrylate as a polymerizable monomer for the shell and ion exchange. 2,2'-azobis [2-methyl-N- (1,1-bis (hydroxymethyl) 2-hydroxyethyl) propionamide] tetrahydrate dissolved in 10 parts of water (manufactured by Wako Junyaku Co., Ltd., trade name: VA086) 0.36 part was added. After further continuing the polymerization for 3 hours, the reaction was stopped to obtain an aqueous dispersion of colored resin particles having a pH of 9.5.
After that, the aqueous dispersion of the colored resin particles was set to 80 ° C., stripping treatment was performed at a nitrogen gas flow rate of 0.6 m3 / (hr · kg) for 5 hours, and then the aqueous dispersion was naturally cooled to 25 ° C. The cooling rate at that time was 3 ° C./min. Next, the obtained aqueous dispersion was acid-washed with sulfuric acid to bring the pH of the system to 6.5 or less while stirring at 25 ° C., and the water was separated by filtration, and then 500 parts of newly ion-exchanged water was added. Was re-slurried and washed with water. Then, dehydration and washing with water were repeated several times to filter and separate the solid content, and then the mixture was placed in a dryer and dried at a temperature of 40 ° C. for 12 hours.
To 100 parts of the colored resin particles obtained above, 0.7 part of silica fine particles having a hydrophobicized number average primary particle size of 7 nm and 1 part of silica fine particles having a hydrophobic number average primary particle size of 50 nm were added. , Mitsui Henshell Mixer (manufactured by Mitsui Miike Kakoki Co., Ltd.) was used for mixing to obtain a comparative toner 9. Table 2 shows the physical characteristics of the obtained comparative toner 9.

表中、Ｘは、磁性体の表面近傍存在指数（個／１μｍ^２）を表す。表中の略称は以下の通り。
ＰＷ：パラフィンワックス、ＣＢ：カーボンブラック、ＰＢ：Ｃ．Ｉ．Ｐｉｇｍｅｎｔ
Ｂｌｕｅ１５：３

In the table, X represents the presence index near the surface of the magnetic material (pieces / 1 μm ² ). The abbreviations in the table are as follows.
PW: paraffin wax, CB: carbon black, PB: C.I. I. Pigment
Blue15: 3

[Example 1]
(Evaluation of low temperature fixability)
The following evaluation was performed using the toner 1.
The evaluation was carried out in an environment of 23 ° C. and 50% RH. FOX DRIVER for fixing media
BOND paper (110 g / m ² ) was used. By using a medium that has a relatively large surface unevenness and is thick paper, white spots, which will be described later, are likely to occur, and the low temperature fixability can be severely evaluated.
As the image forming apparatus, a commercially available LBP-3100 (manufactured by Canon) was used, and the printing speed was modified from 16 sheets / minute to 40 sheets / minute. Furthermore, the size of the fuser was modified to be smaller so that the time during which the media was in contact with the fuser when the media passed through the fuser was 150 msec to 50 msec. While this condition can achieve both high-speed printing and miniaturization of the fuser, it is evaluated that the fixing property is very strict for toner.
When the fuser is cooled to room temperature (25 ° C), the temperature of the fuser is set to 150 ° C, 100 solid black sheets are continuously printed, and white spots in the solid black image on 95 to 100 sheets are printed. The average value of the number of pieces was measured. By continuously printing solid black, the heat of the fuser is taken away by the media, and it becomes a state where sufficient heat is not retained, so that the low temperature fixability of the toner is severely evaluated. White spots are an evaluation that occurs if the toner does not adhere to the paper within the 50 ms set as described above. Therefore, the low temperature fixability of the toner is severely evaluated.
The evaluation result is judged based on the number of white spots. At that time, the average number of white spots generated is visually observed using a microscope or the like capable of magnifying 10 times or more. The smaller the amount, the better the low temperature fixability of the toner. In the present invention, less than 60 pieces were judged to be good. The evaluation results are shown in Table 3.

(Evaluation of sticking and evaluation of hot offset)
The evaluation was carried out in an environment of 33 ° C. and 80% RH. By evaluating in a high temperature and high humidity environment, the heat of the laminated media is less likely to be released, so that it is possible to perform a strict evaluation on sticking. A4 color laser copy paper (manufactured by Canon, 70 g / m ² ) was used as the fixing medium. This media is relatively thin, and good results are likely to be obtained for low temperature fixability. On the other hand, since the toner is easily melted, sticking of the image is likely to occur, and it is possible to make a strict evaluation.
As the image forming apparatus, a commercially available LBP-3100 (manufactured by Canon) was used, and the printing speed was modified from 16 sheets / minute to 40 sheets / minute. This condition is a condition in which the heat of the media does not easily decrease because the interval at which the media discharged from the paper ejection portion are laminated is shortened. Therefore, sticking of the image is likely to occur, and it is possible to strictly evaluate the toner.
After cooling the fuser to 33 ° C, set the temperature of the fuser to 170 ° C, and print 250 sheets of images in which the upper half of the paper is a halftone image and the lower half is a solid white image. did. In this series of evaluations, all the output media were laminated on the output tray, left for 60 minutes or more, and naturally cooled to the evaluation environment temperature of 33 ° C. The evaluation results are shown in Table 3.

<Evaluation criteria for sticking>
When the stacked media are taken out one by one, the number of halftone images stuck to the back side of the media is counted. In the present invention, less than 100 sheets were judged to be good.

<Criteria for determining hot offset>
Count the number of media with toner on the solid white image in the lower half of the paper. In the present invention, less than 50 sheets were judged to be good.

(Evaluation of developability in high temperature and high humidity environment (evaluation of developability))
The evaluation was carried out in an environment of 33 ° C. and 80% RH. By evaluating in a high temperature and high humidity environment, the chargeability of the toner when the charge decay rate is too high tends to be insufficient, and the density of the solid image becomes thin. A commercially available LBP-3100 (manufactured by Canon) was used, and A4 color laser copy paper (manufactured by Canon, 90 g / m ² ) was used. Ten solid images were output in succession. The obtained 10 solid images were measured using a printed image density (Macbeth reflection densitometer (manufactured by Macbeth), and the average value was taken as the solid density. The higher the solid density, the higher the developability in a high temperature and high humidity environment. Is good. In the present invention, 1.20 or more was judged to be good.

[Examples 2 to 12, Comparative Examples 1 to 9]
Examples 2 to 12 and Comparative Examples 1 to 9 were evaluated in the same manner except that the toner was changed. The evaluation results are shown in Table 3. In addition, Examples 11 and 12 are Reference Examples 11 and 12, respectively.

100: Electrostatic latent image carrier (photoreceptor), 102: Toner carrier, 103: Development blade, 114: Transfer member (transfer charging roller), 116: Cleaner container 117: Charging member (charging roller), 121: Laser generator (latent image forming means, exposure device), 123: laser, 124: pickup roller, 125: conveyor belt, 126: fuser, 140: developer, 141: stirring member 601: step (1), 602: Step (2), 603: Step (3) and holding time, 604: Cooling start temperature T1, 605: Cooling stop temperature T2 and holding start temperature T3, 606: After 30 minutes have passed from the start of holding. Temperature T4, 607: Crystallization temperature Tc (° C) of crystalline substance, 608: Temperature indicating glass transition temperature Tg (° C) + 10 ° C of toner particles, 609: Glass transition temperature Tg (° C) of toner particles, 610: Temperature indicating glass transition temperature Tg (° C) -10 ° C of toner particles, 611: Cooling rate, 612: Cooling rate 2
1: Large domain of crystalline material 2: Small domain of crystalline material 3: Region within 25% of the distance between the contour and the center of gravity of the cross section from the contour of the toner particle cross section

Claims (10)

A toner having toner particles containing a binder resin, a crystalline material, and a colorant.
The charge amount of the toner is -50 μC / g or more and -20 μC / g or less.
The charge decay rate of the toner when measured at 25 ° C is -2.5 x 10 ^-3 (1 / s ^(1/2) ) or more-0.1 x 10 ^-3 (1 / s ⁽ 1/2)). ⁾ ) Below,
The charge decay rate when the toner was heated at 80 ° C. for 1 minute and measured at 25 ° C. was −7.0 × 10 ^-3 (1 / s ^(1/2) ) or more-4.0 × 10 ⁻ . ³ (1 / s ^(1/2) ) or less ,
In the cross section of the toner particles observed by a transmission electron microscope,
The microdomains of the crystalline material are present and
The toner is characterized in that the microdomain is present within 25% of the distance between the contour of the cross section and the center of gravity of the cross section by 60% by number or more and 100% by number or less . The toner according to claim 1, wherein the number average value of the major axis of the minute domain is 50 nm or more and 350 nm or less. The toner according to claim 1 or 2 , wherein the crystalline material contains a monoester compound. The toner according to claim 3 , wherein the monoester compound has a melting point of 60 ° C. or higher and 72 ° C. or lower. The toner according to claim 3 or 4 , wherein the average number of carbon atoms per molecule of the monoester compound is 36 or more and 42 or less. The colorant contains a magnetic material and contains
The invention according to any one of claims 1 to 5 , wherein the surface vicinity index of the magnetic material obtained by observing the toner with a scanning electron microscope is 4.0 pieces / 1 μm ² or more and 8.0 pieces / 1 μm ² or less. Toner. The microdomain is 25, which is the distance between the contour of the cross section and the center of gravity of the contour and the cross section.
The toner according to any one of claims 1 to 6, wherein 65% or more and 100% or less are present within%. The charge decay rate when the sample obtained by heating the toner at 80 ° C. for 1 minute was measured at 25 ° C. was −7.0 × 10. ^-3 (1 / s ^(1/2) ) Above-5.0 × 10 ^-3 (1 / s ^(1/2) ) The toner according to any one of claims 1 to 6 below. The method for manufacturing a toner according to any one of claims 1 to 8 .
A method for producing toner, which comprises the following steps (1) to (3) in this order.
Step (1): The dispersion liquid in which the toner particles are dispersed in an aqueous medium is subjected to the higher temperature of the crystallization temperature Tc (° C.) of the crystalline material and the glass transition temperature Tg (° C.) of the toner particles. Step to make the temperature higher Step (2): The dispersion is charged from a temperature higher than the higher of the crystallization temperature Tc (° C) of the crystalline material and the glass transition temperature Tg (° C) of the toner particles. Step of cooling to a temperature of Tg (° C.) or less at a cooling rate of 5.00 ° C./min or more Step (3): The dispersion liquid that has undergone step (2) is placed in the temperature range of Tg ± 10 ° C. The process of holding for 30 minutes or more In the step (1), the dispersion is held at a temperature higher than the higher of the crystallization temperature Tc (° C) of the crystalline material and the glass transition temperature Tg (° C) of the toner particles for 30 minutes or more. The method for producing a toner according to claim 9 .

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