JP7631099B2 - Toner and manufacturing method thereof - Google Patents

Description

The present invention relates to a toner used in recording methods that utilize electrophotography, electrostatic recording, and toner jet recording.

In recent years, the fields in which electrophotographic image formation is used have become more diverse, ranging from printers and copiers to commercial printing machines. Accordingly, the demand for higher image quality, higher speed, and higher durability for electrophotography has been increasing. In addition, as the uses have become more diverse, the demand for smaller and lighter bodies has also been increasing.
In order to achieve high image quality, toner is required to reproduce a latent image faithfully. In order to reproduce a latent image faithfully, it is effective to precisely control the charge of the toner. If the charge control of the toner is insufficient, problems such as fog caused by low charge toner developing in non-image areas, and uneven density of the image caused by regulation failure due to overcharged toner strongly adhering to the toner carrier occur, which are factors that hinder the faithful reproduction of the latent image.
For this reason, in order to improve image quality, there have been many studies into controlling the charge of the toner by attaching a material whose chargeability can be precisely controlled to the toner surface or by coating the toner surface with a material that has excellent chargeability.
Japanese Patent Application Laid-Open No. 2003-233693 discloses a toner that achieves suppression of overcharging by externally adding fine alumina particles that have been surface-treated with an organosilicon compound to the toner.
Patent Document 2 discloses a toner having a layer containing an organosilicon polymer containing a polyvalent acid metal salt on the surface of a toner particle, and by controlling the average area of the polyvalent acid metal salt and the coefficient of variation of the area of the polyvalent acid metal salt, the toner has improved charge rise properties, is capable of suppressing overcharging of the toner, and is also capable of suppressing contamination of components.
On the other hand, in order to increase the speed, it is necessary to supply toner quickly to a developing member such as a developing roller, and therefore density stability from the second sheet onwards (hereinafter referred to as solid image tracking) becomes an issue, particularly when continuously printing images with a very high print rate (hereinafter referred to as solid image). In order to stabilize the density of a solid image, it is necessary to continue to supply a necessary amount of toner to a developing member such as a developing roller even during high-speed printing.
Patent Document 3 discloses a toner in which the interparticle force between two toner particles is controlled to suppress the aggregation of toner on a developing roller, thereby improving solid printing performance, and further, the toner has an organosilicon polymer on its surface to make the surface charge distribution within the toner particles uniform, thereby improving transfer dust (the phenomenon in which toner is scattered around characters or line images) and half-tone reproducibility.

Japanese Patent Application Publication No. 8-184988 JP 2019-128516 A JP 2020-71363 A

The toner described in Patent Document 1 is excellent at suppressing uneven density in images, but the adhesion to the base material is insufficient when the alumina powder is merely mechanically added to the outside, and when the toner is subjected to a large shear as the printing process becomes faster, the additive comes off during durability, and further, the detached additive contaminates components, causing problems such as development streaks.
The toner described in the above Patent Document 2 suppresses overcharging, and achieves suppression of member contamination by the presence of the polyvalent metal salt together with the layer containing the organosilicon condensate.However, Patent Document 2 describes that the form of the polyvalent metal salt is preferably fine particles, but does not pay attention to the significance and function of small-diameter polyvalent metal salt particles and large-diameter polyvalent metal salt particles, and does not control the number ratio of both.Therefore, in response to the recent demand for high speed and miniaturization without toner supplying members, the amount of toner supplied to the developing member is insufficient, and the problem of reduced solid followability remains.
The toner described in the above Patent Document 3 has a uniform surface charge distribution within the toner particles, but the uniform surface charge distribution within a single toner particle alone cannot eliminate the charge bias between toner particles. Therefore, the suppression of density unevenness by suppressing overcharging is insufficient, and further improvement is required to achieve the image quality level required in the future. In addition, in response to the recent demand for high speed and miniaturization without a toner supply member, the amount of toner supplied to the developing member is insufficient, and the problem of reduced solid followability remains.
The present invention provides a toner which solves the above problems, can eliminate uneven density in images by suppressing overcharging, has good solid image conformability, and causes little member contamination even over long periods of use.

The present invention provides a toner having toner particles containing a binder resin,
polyvalent acid metal salt particles of a polyvalent acid and a compound containing at least one metal element selected from the metal elements included in Groups 3 to 13 are present on the surface of the toner particles,
In a reflected electron image of the toner taken at a magnification of 50,000 times using a scanning electron microscope, when the percentage of the number of the polyvalent acid metal salt particles having an area of 100 ^nm2 or less to the total number of the polyvalent acid metal salt particles is A and the percentage of the number of the polyvalent acid metal salt particles having an area of 500 ^nm2 or more is B, the following formulae (1) and (2) are satisfied:
83.0≦A (1)
1.7≦B≦17.0 (2)
The toner is characterized in that in the reflected electron image, the ratio of the area of the polyvalent acid metal salt particles having an area of 100 nm2 or ^less to the total area of the toner particle surface in the observed field of view is 0.3% or more and 16.0% or less.
The present invention also provides a method for producing the toner having the above-mentioned configuration,
The present invention relates to a method for producing a toner, characterized in that polyvalent acid metal salt particles made of a compound containing at least one metal element selected from the metal elements included in Groups 3 to 13 and a polyvalent acid are produced by reacting the compound containing the metal element with a polyvalent acid in an aqueous medium containing toner base particles and an organosilicon compound.

The present invention provides a toner that can improve solid image conformance and suppress uneven image density by suppressing overcharging, while also minimizing toner degradation over long periods of use.

In the present invention, the expressions "xx or more and xx or less" or "xx to xx" that express a numerical range refer to a numerical range including the lower and upper limit endpoints, unless otherwise specified.

In the toner charging process, friction between the charging member or carrier (hereinafter collectively referred to as the charging member) and the toner does not occur uniformly, which can result in overcharged toner and undercharged toner. In order to prevent overcharging of the toner, it is effective to increase the conductive path between the overcharged toner and undercharged toner and to make the charge distribution of the toner particles uniform. Also, in order to quickly transfer the charge inside the toner to the outside, it is necessary to improve the conductivity between the toner mother body and the shell layer (the surface layer of the toner particle).

In addition, in order to improve solid print conformability, simply controlling the fluidity and cohesiveness of the toner, as in the past, is no longer sufficient to meet the demands of higher speeds in recent years; it is necessary to further increase the supply of toner to developing members such as developing rollers by utilizing the force that can more actively transport the toner to the developing member.

Furthermore, if excessive charging control and improved solid print conformance are achieved using external additives, the additives will come off over long periods of use, causing contamination of components and developing streaks and other problems, so a means other than external additives is necessary.

As a result of extensive research, the inventors have found that in order to suppress uneven density in images by suppressing overcharging and to improve solid-color conformity, a toner having the following composition satisfies the above requirements.

That is, a toner containing toner particles having a binder resin, wherein polyvalent acid metal salt particles of a polyvalent acid and a compound containing at least one metal element selected from the metal elements included in Groups 3 to 13 are present on the surface of the toner particles,
In a reflected electron image of the toner taken at a magnification of 50,000 times using a scanning electron microscope, when the percentage of the number of the polyvalent acid metal salt particles having an area of 100 ^nm2 or less to the total number of the polyvalent acid metal salt particles is A and the percentage of the number of the polyvalent acid metal salt particles having an area of 500 ^nm2 or more is B, the following formulae (1) and (2) are satisfied:
83.0≦A (1)
1.7≦B≦17.0 (2)

The above requirement is satisfied when the ratio of the area of the polyvalent acid metal salt particles having an area of 100 ^nm2 or less to the total area of the toner particle surface in the observed field of view in the reflected electron image is 0.3% or more and 16.0% or less.

The inventors speculate that the mechanism behind this effect is as follows:

To control charging, it is necessary to quickly transfer the charge inside the toner to the shell layer and the low-charge toner present in the vicinity of the overcharged toner. On the surface of the toner particles of the present invention, there is a polyvalent acid metal salt of a polyvalent acid and a compound containing at least one metal element selected from the metal elements included in Groups 3 to 13. The metal elements included in Groups 3 to 13 have a valence of 2 or more, and the divalent or higher acid forms a crosslinked structure with the metal element, and the crosslinked structure promotes the transfer of charge and suppresses overcharging.

In particular, salts composed of metal elements included in groups 3 to 13 and polyvalent acids have lower water absorption than salts containing only metal elements from groups 1 and 2, and therefore show less change in performance in suppressing overcharging over long periods of use and improving solid print followability, which will be described later.

It is more preferable that the metal element is a Group 4 element. Group 4 elements are most stable when their oxidation number is +4. Therefore, they form a cross-linked structure with the polyacid, and this cross-linked structure promotes the transfer of charges and suppresses overcharging.

Specific examples of metal elements that may be used in the present invention include titanium (Group 4, electronegativity: 1.54), zirconium (Group 4, electronegativity: 1.33), aluminum (Group 13, electronegativity: 1.61), zinc (Group 12, electronegativity: 1.65), indium (Group 13, electronegativity: 1.78), hafnium (Group 4, electronegativity: 1.30), iron (Group 8, electronegativity: 1.83), copper (Group 11, electronegativity: 1.90), and silver (Group 11, electronegativity: 1.93).

The polyacid used in the present invention may be any divalent or higher acid.

A salt composed of a divalent or higher acid and the above-mentioned metal element creates a cross-linked structure between the compound containing the metal element and the polyvalent acid, and this cross-linked structure promotes the transfer of electrons, thereby preventing overcharging.

Specific examples of polyvalent acids used in the present invention include inorganic acids such as phosphoric acid (trivalent), carbonic acid (divalent), and sulfuric acid (divalent); and organic acids such as dicarboxylic acids (divalent) and tricarboxylic acids (trivalent). Specific examples of organic acids include the following dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, and terephthalic acid; and tricarboxylic acids such as citric acid, aconitic acid, and trimellitic anhydride. Among these, phosphoric acid, carbonic acid, and sulfuric acid are preferred, and phosphoric acid is more preferred.

Specific examples of polyvalent acid metal salts combining the above metals and the above polyvalent acids include metal phosphates such as titanium phosphate compounds, zirconium phosphate compounds, aluminum phosphate compounds, and copper phosphate compounds; metal sulfates such as titanium sulfate compounds, zirconium sulfate compounds, and aluminum sulfate compounds; metal carbonates such as titanium carbonate compounds, zirconium carbonate compounds, and aluminum carbonate compounds; and metal oxalates such as titanium oxalate compounds. Among these, metal phosphates are preferred because the phosphate ions crosslink the metals, giving them high strength, and titanium phosphate compounds are even more preferred.

There are no particular limitations on the method for obtaining the polyvalent acid metal salt, and any conventionally known method can be used. Among these, a method in which a metal compound serving as a metal source is reacted with a polyvalent acid ion in an aqueous medium to obtain a polyvalent acid metal salt is preferred.

When obtaining a polyvalent acid metal salt by the above method, any conventionally known metal compound can be used as the metal source without any particular restrictions, so long as it is a metal compound that gives a polyvalent acid metal salt by reacting with a polyvalent acid ion.

Among these, metal chelates are preferred because the reaction is easy to control and they react quantitatively with polyvalent acid ions. Furthermore, lactate chelates such as titanium lactate and zirconium lactate are more preferred from the viewpoint of solubility in aqueous media.

Specific examples of metal sources used in the present invention include metal chelates such as titanium lactate, titanium tetraacetylacetonate, titanium lactate ammonium salt, titanium triethanolamine, zirconium lactate, zirconium lactate ammonium salt, aluminum lactate, aluminum trisacetylacetonate, and copper lactate, and metal alkoxides such as titanium tetraisopropoxide, titanium ethoxide, zirconium tetraisopropoxide, and aluminum trisisopropoxide.

When obtaining a polyvalent acid metal salt by the above method, the polyvalent acid ions can be the ions of the polyvalent acids described above. When added to the aqueous medium, the polyvalent acid itself can be added, or a water-soluble polyvalent acid metal salt can be added to the aqueous medium and dissociated in the aqueous medium.

As mentioned above, the presence of polyvalent metal salt particles on the surface of the toner particles promotes the transfer of charges inside and outside the toner particles, and can suppress overcharging. However, to effectively exert this overcharging suppression effect, it is necessary for a certain proportion of small-diameter polyvalent metal salt particles to be present.

In the present invention, the presence of a certain percentage or more of small-diameter polyvalent metal salt particles suppresses overcharging.

When the total volume of polyvalent metal salt particles is constant, small-diameter polyvalent metal salt particles have a larger contact area with the toner matrix than large-diameter polyvalent metal salt particles. Therefore, when a certain proportion or more of small-diameter polyvalent metal salt particles are present, the conductive path between the polyvalent metal salt particles and the toner matrix increases, allowing the charge inside the toner to be smoothly transferred to the toner surface.

In addition, the small-diameter polyvalent metal salt particles increase the contact area between the polyvalent metal salt particles between the toner particles, and thus promote the transfer of electric charges between the toner particles. In particular, when the above formula (1) is satisfied and the area ratio of the polyvalent metal salt particles having an area of 100 ^nm2 or less is 0.3% or more and 16.0% or less, the small-diameter polyvalent metal salt particles have an optimal number for forming a sufficient conductive path. As a result, it is believed that overcharging is suppressed.

On the other hand, as mentioned above, to improve solid print tracking, it is necessary to develop a force that can more actively transport the toner to the developing member, and this cannot be achieved by simply controlling the proportion of small-diameter polyvalent metal salt particles.

In the present invention, the presence of a certain percentage of large-diameter polyvalent metal salt particles increases the toner supply force and improves solid-color conformability.

Gradient force is thought to be involved in the increase in toner supply force in the present invention. Gradient force is a force that acts on a conductor when it is present in an electric field. The electric field causes electrostatic polarization inside the conductor, and a force acts in the direction where the electric field is stronger by the difference in the strength of the electric field between where a positive charge is generated and where a negative charge is generated. In the present invention, when a voltage is applied to a developing member such as a developing roller, an electric field is formed around the developing member. The electric field causes electrostatic polarization within the polyvalent metal oxide particles, which are conductors, and it is thought that a gradient force acts on the polyvalent metal oxide particles in the direction of the developing member.

In particular, when the polyvalent acid metal salt particles contain a metal element included in Groups 3 to 13 as in the present invention, a polarity difference between the metal element and the polyvalent acid is likely to occur, and the polarization in the polyvalent acid metal salt particles is large, so that the gradient force in the electric field can be strengthened. In order to further strengthen the gradient force, it is preferable that the Pauling electronegativity of the metal element is 1.30 or more and 1.60 or less. Examples include titanium (Group 4, electronegativity: 1.54) and zirconium (Group 4, electronegativity: 1.33). When the electronegativity of the metal element is in the above range, in addition to suppressing moisture absorption, a polarity difference with the polyvalent acid is likely to occur, and the polarization in the polyvalent acid metal salt is large, so that the gradient force in the electric field can be further strengthened.

The Pauling electronegativity was calculated using the value given in "Chemical Handbook: Basics, 5th Revised Edition, Maruzen Publishing, edited by the Chemical Society of Japan (2004)."

It is also known that the gradient force F is expressed by the following formula (6) in the case of a sphere with a relative dielectric constant of _εr .
F=2πε ₀ {(ε _r -2)/(ε _r +2)}a ³ gradE ² (6)

Here, ε ₀ is the dielectric constant of a vacuum, gradE is the gradient of the electric field, and a is the radius of the conductive particle.

According to equation (6), the larger the radius a of the conductive particle, the stronger the gradient force.

Thus, the larger the particle size of the conductive fine particles, the stronger the gradient force. When formula (2) above is satisfied, the number of large-diameter polyvalent metal salt particles is sufficiently large, and the gradient force works effectively. As a result, it is believed that the supply of toner to the developing member is sufficiently increased, and solid followability is improved. Thus, in order to improve the gradient force, a certain proportion of large-diameter polyvalent metal salt particles is necessary.

To summarise the above mechanisms, it is believed that the presence of a certain number of small polyvalent metal salt particles and a certain number of large polyvalent metal salt particles provides the effects of both suppressing overcharging, mainly through the small polyvalent metal salt particles, and improving solid print conformability through the large polyvalent metal salt particles.

Furthermore, as an effect of using small-diameter polyvalent metal salt particles and large-diameter polyvalent metal salt particles in combination, when a certain amount or more of large-diameter polyvalent metal salt particles are present between the small-diameter polyvalent metal salt particles, the polyvalent metal salt particles present on the surface of each toner particle are interlocked with each other, increasing the conductive path between the toner particles. In particular, by satisfying formulas (1) and (2), the ratio of the number of small-diameter polyvalent metal salt particles to the number of large-diameter polyvalent metal salt particles is optimized, and it is believed that interlocking is more likely to occur.

In addition, when formulas (1) and (2) are satisfied, the unevenness of the toner surface caused by the particle size difference of the polyvalent acid metal salt particles causes the elastic developing roller to deform, increasing the contact area with the toner surface, and therefore increasing the conductive path between the toner and the developing roller, which is also thought to contribute to suppressing overcharging.

The toner of the present invention is described in detail below.

<Surface Condition of Toner Particles>
The toner of the present invention is a toner having toner particles containing a binder resin, and polyvalent acid metal salt particles of a compound containing at least one metal element selected from metal elements included in groups 3 to 13 and a polyvalent acid are present on the surface of the toner particles, and in a reflected electron image of the toner taken with a scanning electron microscope at a magnification of 50,000 times, when the percentage (%) of the number of the polyvalent acid metal salt particles having an area of 100 ^nm2 or less to the total number of the polyvalent acid metal salt particles is A and the percentage (%) of the number of the polyvalent acid metal salt particles having an area of 500 ^nm2 or more to the total number of the polyvalent acid metal salt particles is B, the following formulas (1) and (2) are satisfied, and in the reflected electron image, the percentage of the area of the polyvalent acid metal salt particles having an area of 100 ^nm2 or less to the total area of the toner particle surface in the observed field of view is 0.3% to 16.0%. It is also preferable that the above B satisfies the following formula (7).
83.0≦A (1)
1.7≦B≦17.0 (2)
1.7≦B≦10.0 (7)

By satisfying the above formula (1), the number ratio of small-diameter polyvalent metal salt particles is sufficiently large, and a sufficient conductive path is formed. And by satisfying the above formula (2), the number ratio of large-diameter polyvalent metal salt particles is sufficiently large, and the action of the gradient force is enhanced, and the detachment of the polyvalent metal salt particles from the surface of the base body caused by the excessive presence of large-diameter polyvalent metal salt particles and the associated contamination of the components can be suppressed. Furthermore, by making the area ratio of the polyvalent metal salt particles having an area of 100 ^nm2 or less 0.3% or more, a sufficient amount of polyvalent metal salt particles can be present on the toner particle surface to express the effects obtained by the above formulas (1) and ⁽² ). Furthermore, by making the area ratio of the polyvalent metal salt particles having an area of 100 nm2 or less 16.0% or less, the contamination of the components caused by the detachment of the polyvalent metal salt particles from the toner particle surface and the charging failure due to leakage caused by the excessive formation of the conductive path can be suppressed.

The above A, B and the area ratio of the polyvalent acid metal salt particles having an area of 100 nm2 or ^less can be controlled by the production method such as the amount of raw materials when adhering the polyvalent acid metal salt particles to the toner base particles and the alcohol concentration in the system. The production method will be described later.

In the toner of the present invention, when the percentage (%) of the number of the polyvalent acid metal salt particles having an area of 100 nm2 or ^more and 500 ^nm2 or less to the total number of the polyvalent acid metal salt particles is defined as C in a reflected electron image of the toner photographed at a magnification of 50,000 times using a scanning electron microscope, it is preferable that the toner satisfies the following formula (3), and it is more preferable that the toner satisfies the following formula (8):
3.0<C≦15.3 (3)
4.0<C≦15.3 (8)

Since polyvalent acid metal salt particles having an area of 100 ^nm2 or more and 500 nm2 or ^less contribute to both the formation of a conductive path and the expression of a gradient force, when the above formula (3) is satisfied, the number of polyvalent acid metal salt particles having an area of 100 ^nm2 or more and 500 ^nm2 or less becomes optimal, making it easier to achieve both the effects of the present invention, namely, suppression of overcharging and improvement of solid conformability.

In the toner of the present invention, the average area of the polyvalent acid metal salt particles is preferably 10 ^nm2 or more and 5000 ^nm2 or less, more preferably 14 ^nm2 or more and 3000 ^nm2 or less. When the average area of the polyvalent acid metal salt particles is 10 ^nm2 or more, the sum of the gradient forces acting on the polyvalent acid metal salt particles present on the toner surface becomes large, and it becomes easier to achieve solid follow-up improvement. In addition, when the average area of the polyvalent acid metal salt particles is 5000 ^nm2 or less, the contact area with the toner mother body and the organosilicon polymer described later becomes sufficiently large, so that the polyvalent acid metal salt particles can be prevented from migrating from the toner particle surface to other members. In addition, it is possible to suppress the electric field around the developing member from being disturbed due to member contamination, and to prevent the action of the gradient force from being reduced.

The average area of the polyvalent acid metal salt particles can be controlled by controlling the proportion of coarse particles in the manufacturing method, or by the temperature at which the polyvalent acid metal salt particles are produced.

In the toner of the present invention, the coefficient of variation of the area of the polyvalent acid metal salt particles is preferably 10.0 or less, and more preferably 8.0 or less. When the coefficient of variation of the area of the polyvalent acid metal salt particles is 10.0 or less, the polyvalent acid metal salt particles are highly dispersible, and good conductive paths are easily formed. In addition, since the variation in the charge amount of the polyvalent acid metal salt particles is reduced, a gradient force acts on the entire toner particle, and the effect of improving solid followability is further enhanced.

The coefficient of variation of the area of the polyvalent acid metal salt particles can be controlled by the manufacturing method, such as the production rate of the polyvalent acid metal salt particles.

In the toner of the present invention, in a backscattered electron image of the toner taken at a magnification of 50,000 times using a scanning electron microscope, the ratio of the area of the polyvalent acid metal salt particles to the total area of the toner particle surface in the observed field of view is preferably 1.1% or more and 26.3% or less, and more preferably 1.1% or more and 13.1% or less.

When the area ratio of the polyvalent metal salt particles is 1.1% or more, the absolute amount of small-diameter polyvalent metal salt particles that mainly contribute to suppressing overcharging and large-diameter polyvalent metal salt particles that contribute to improving solid-surface conformability increases, and the effects of suppressing overcharging and improving solid-surface conformability are significantly manifested. In addition, when the area ratio of the polyvalent metal salt particles is 13.1% or less, detachment of the polyvalent metal salt particles from the substrate surface and the resulting contamination of components can be suppressed.

The ratio of the area of the polyvalent acid metal salt particles to the total area of the toner particle surface can be controlled by the amount of raw materials added, etc.

The toner of the present invention preferably satisfies the following formula (4), and more preferably satisfies the following formula (9), when the average height Ha (nm) of the polyvalent acid metal salt particles in the normal direction is determined in a mapping analysis using an energy dispersive X-ray spectrometer (EDS) on a cross section of the toner particle observed under a transmission electron microscope (TEM).
2.5≦Ha≦50.0 (4)
10.0≦Ha≦40.0 (9)

Ha of 2.5 or more makes it easier for the polyvalent metal salt particles present on the surface of each toner to become bitten by each other, making it easier to form conductive paths between the toner particles, which is highly effective in suppressing overcharging. Also, Ha of 50.0 or less makes it possible to suppress the polyvalent metal salt particles from coming off the surface of the base material, which occurs when the polyvalent metal salt particles are too high and shear is easily applied to the surface during durability, thereby suppressing contamination of components.

In the toner of the present invention, when a metal element contained in the polyvalent acid metal salt particles is defined as a metal element M, the amount of metal of the metal element M contained in the toner determined by X-ray fluorescence analysis is defined as M1 (detection intensity kcps), 1.0 g of the toner is dispersed in a mixed aqueous solution consisting of 31.0 g of a 61.5 mass % sucrose aqueous solution and 6.0 g of a 10 mass % aqueous neutral detergent for cleaning precision measuring instruments, which is composed of a nonionic surfactant, an anionic surfactant, and an organic builder, and the toner is obtained by subjecting the toner to a process (a) of shaking 300 times per minute using a shaker for 20 minutes, and the amount of metal of the metal element M contained in the toner (a) determined by X-ray fluorescence analysis is defined as M2 (detection intensity kcps), it is preferable that M1 and M2 satisfy the following formula (5), and more preferably satisfy formula (10).
0.85≦M2/M1 (5)
0.90≦M2/M1 (10)

By satisfying formula (5), the polyvalent acid metal salt particles are less likely to detach from the toner particle surface over long periods of use, preventing contamination of components, and the effects of suppressing overcharging and improving solid-color conformability can be achieved over long periods of use.

The value of M2 can be controlled by controlling the adhesion strength of the polyvalent acid metal salt particles to the toner particle surface through the manufacturing method and the amount of organosilicon polymer added.

The materials contained in the toner of the present invention are described in detail below.

<Organosilicon polymers and organosilicon compounds>
The toner of the present invention preferably has an organosilicon compound on the surface of the toner particles, and the compound is preferably an organosilicon polymer.

The organosilicon polymer used in the present invention is not particularly limited and may be any conventionally known organic polymer. Among them, it is preferable to use an organosilicon polymer having a partial structure represented by formula (11).
R-SiO _3/2 formula (11)
(In formula (11), R represents an alkyl group, an alkenyl group, an acyl group, an aryl group, or a methacryloxyalkyl group.)

The above formula (11) indicates that the organosilicon polymer has an organic group and a silicon polymer portion. As a result, the organosilicon polymer containing the partial structure represented by the above formula (11) adheres strongly to the toner base particles because the organic group has affinity with the toner base particles, and adheres strongly to the polyvalent acid metal salt because the silicon polymer portion has affinity with the polyvalent acid metal salt. In this way, the polyvalent acid metal salt can be more firmly adhered to the toner base particles through the organosilicon polymer.

In addition, when the metal element belongs to Groups 3 to 13, the valence of the metal element is 2 or more, and it can form a crosslinked structure with the organosilicon compound, so that a crosslinked structure with the polymer of the organosilicon compound can be formed on the toner particle surface. This crosslinked structure suppresses the migration of the polyvalent acid metal salt particles to the developing member, and promotes the transfer of charge on the toner surface and between toner particles, thereby enhancing the effect of suppressing overcharging.

Furthermore, the organosilicon compound bridges the polyvalent metal salt particles, forming a network of the organosilicon compound and the polyvalent metal salt particles on the surface of the toner particles. The polyvalent metal salt particles have high thermal conductivity, so they can quickly transfer heat from the fixing device to the toner during fixing, but when the above network is present, the heat received by a portion of the toner particles can be quickly transferred to the entire particle surface. In particular, small-diameter polyvalent metal salt particles are widely dispersed on the toner particles and contribute greatly to network formation, so the presence of a certain number or more of them is highly effective in improving fixing. From the viewpoint of achieving both the above effect and suppressing deterioration of fixing due to high coating of the organosilicon compound, the content of the organosilicon compound is preferably 0.3 parts by mass or more and 20.0 parts by mass or less relative to 100.0 parts by mass of the binder resin or polymerizable monomer.

The organosilicon compound for obtaining the organosilicon polymer can be any conventionally known organosilicon compound without any particular limitations, and is preferably at least one organosilicon compound selected from the group consisting of organosilicon compounds represented by the following formula (12):
R-Si-(Ra) ₃ formula (12)
(In formula (12), each Ra independently represents a halogen atom or an alkoxy group, and each R independently represents an alkyl group, an alkenyl group, an aryl group, an acyl group, or a methacryloxyalkyl group.)

Specific examples of the silane compounds represented by formula (12) include trifunctional methylsilane compounds such as methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, and methylethoxydimethoxysilane; trifunctional silane compounds such as ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, and hexyltriethoxysilane; and trifunctional phenylsilane compounds such as phenyltrimethoxysilane and phenyltriethoxysilane. trifunctional vinyl silane compounds such as vinyl trimethoxysilane and vinyl triethoxysilane; trifunctional allyl silane compounds such as allyl trimethoxysilane, allyl triethoxysilane, allyl diethoxy methoxysilane and allyl ethoxy dimethoxysilane; trifunctional gamma-methacryloxypropyl silane compounds such as gamma-methacryloxypropyl trimethoxysilane, gamma-methacryloxypropyl triethoxysilane, gamma-methacryloxypropyl diethoxy methoxysilane and gamma-methacryloxypropyl ethoxy dimethoxysilane; and trifunctional silane compounds such as gamma-methacryloxypropyl trimethoxysilane, gamma-methacryloxypropyl triethoxysilane, gamma-methacryloxypropyl diethoxy methoxysilane and gamma-methacryloxypropyl ethoxy dimethoxysilane.

<Binder resin>
The toner of the present invention contains a binder resin.

As the binder resin, any conventionally known resin can be used without any particular restrictions. Specific examples include vinyl resins, polyester resins, polyurethane resins, and polyamide resins. Polymerizable monomers that can be used to manufacture vinyl resins include styrene monomers such as styrene and α-methylstyrene; acrylic acid esters such as methyl acrylate and butyl acrylate; methacrylic acid esters such as methyl methacrylate, 2-hydroxyethyl methacrylate, t-butyl methacrylate, and 2-ethylhexyl methacrylate; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated dicarboxylic acids such as maleic acid; unsaturated dicarboxylic anhydrides such as maleic anhydride; nitrile vinyl monomers such as acrylonitrile; halogen-containing vinyl monomers such as vinyl chloride; and nitro vinyl monomers such as nitrostyrene.

Among them, it is preferable to use a vinyl resin or a polyester resin as the binder resin.

<Coloring Agent>
The toner of the present invention may contain a colorant. As the colorant, there is no particular limitation, and conventionally known pigments and dyes of black, yellow, magenta, cyan, and other colors, magnetic materials, and the like can be used.

Black colorants include black pigments such as carbon black.

Yellow colorants include yellow pigments and yellow dyes such as monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, benzimidazolone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

Specific examples include C.I. Pigment Yellow 74, 93, 95, 109, 111, 128, 155, 174, 180, 185, C.I. Solvent Yellow 162, etc.

Examples of magenta colorants include magenta pigments and magenta dyes such as monoazo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

Specific examples include C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, and C.I. Pigment Violet 19.

Cyan colorants include cyan pigments and cyan dyes such as copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds.

Specific examples include C.I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

The content of the colorant is preferably 1.0 parts by mass or more and 20.0 parts by mass or less per 100.0 parts by mass of the binder resin or polymerizable monomer.

The toner can also be made magnetic by adding a magnetic material.

In this case, the magnetic material can also serve as a colorant.

Magnetic materials include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel, or alloys and mixtures of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium.

<Wax>
The toner of the present invention may contain a wax. As the wax, any conventionally known wax may be used without any particular limitation. Specifically, there may be used esters of monohydric alcohols and monocarboxylic acids, such as behenyl behenate, stearyl stearate, and palmityl palmitate; esters of dihydric carboxylic acids and monoalcohols, such as dibehenyl sebacate; esters of dihydric alcohols and monocarboxylic acids, such as ethylene glycol distearate and hexanediol dibehenate; esters of trihydric alcohols and monocarboxylic acids, such as glycerin tribehenate; esters of tetrahydric alcohols and monocarboxylic acids, such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate; dipentaerythritol hexastearate and dipentaerythritol tetrastearate; Examples of such waxes include esters of hexahydric alcohols such as tall hexapalmitate and monocarboxylic acids; esters of polyfunctional alcohols such as polyglycerin behenate and monocarboxylic acids; natural ester waxes such as carnauba wax and rice wax; petroleum-based hydrocarbon waxes and derivatives thereof such as paraffin wax, microcrystalline wax, and petrolatum; hydrocarbon waxes and derivatives thereof produced by the Fischer-Tropsch process; polyolefin-based hydrocarbon waxes and derivatives thereof such as polyethylene wax and polypropylene wax; higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid; and acid amide waxes.

From the viewpoint of releasability, the wax content is preferably 1.0 parts by mass or more and 30.0 parts by mass or less, and more preferably 5.0 parts by mass or more and 20.0 parts by mass or less, per 100.0 parts by mass of the binder resin or polymerizable monomer.

<Charge Control Agent>
The toner of the present invention may contain a charge control agent within a range that does not inhibit the expression of gradient force and charge control by the polyvalent acid metal salt particles. As the charge control agent, any known charge control agent can be used without any particular limitation.

Specific examples of negative charge control agents include the following: metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, and dicarboxylic acids, or polymers or copolymers having metal compounds of the aromatic carboxylic acids; polymers or copolymers having sulfonic acid groups, sulfonate salt groups, or sulfonate ester groups; metal salts or metal complexes of azo dyes or azo pigments; boron compounds, silicon compounds, and calixarenes.

On the other hand, examples of positive charge control agents include the following: quaternary ammonium salts, polymeric compounds having quaternary ammonium salts in the side chain; guanidine compounds; nigrosine compounds; imidazole compounds. As polymers or copolymers having a sulfonate group or a sulfonate ester group, homopolymers of sulfonic acid group-containing vinyl monomers such as styrene sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, vinyl sulfonic acid, and methacrylsulfonic acid, or copolymers of the vinyl monomers shown in the binder resin section and the above-mentioned sulfonic acid group-containing vinyl monomers can be used.

The content of the charge control agent is preferably 0.01 parts by mass or more and 5.0 parts by mass or less per 100.0 parts by mass of the binder resin or polymerizable monomer.

<External Additives>
Toner particles having an organosilicon polymer on the surface thereof exhibit excellent properties such as flowability even in the absence of external additives, but may contain external additives for further improvement.

As the above external additive, any external additive known in the art can be used without any particular restrictions.

Specific examples include the following: raw silica fine particles such as wet-process silica and dry-process silica, or silica fine particles obtained by surface-treating the raw silica fine particles with a treatment agent such as a silane coupling agent, a titanium coupling agent, or silicone oil; and resin fine particles such as vinylidene fluoride fine particles and polytetrafluoroethylene fine particles.

The content of the external additive is preferably 0.1 parts by mass or more and 5.0 parts by mass or less per 100.0 parts by mass of the toner particles.

Next, the method for obtaining the toner of the present invention will be described in detail below.

<Method of Manufacturing Toner Base Particles>
The method for producing the toner base particles (the toner particles before the polyvalent acid metal salt particles are attached are also referred to as "toner base particles") is not particularly limited, and a suspension polymerization method, a solution suspension method, an emulsion aggregation method, a pulverization method, or the like can be used.

As an example, the method for obtaining toner base particles using suspension polymerization is described below.

First, a polymerizable monomer capable of producing a binder resin and various additives, if necessary, are mixed, and the materials are dissolved or dispersed using a disperser to prepare a polymerizable monomer composition.

Various additives include colorants, waxes, charge control agents, polymerization initiators, chain transfer agents, etc.

Examples of dispersing machines include homogenizers, ball mills, colloid mills, and ultrasonic dispersers.

Next, the polymerizable monomer composition is poured into an aqueous medium containing poorly water-soluble inorganic fine particles, and droplets of the polymerizable monomer composition are prepared using a high-speed disperser such as a high-speed stirrer or ultrasonic disperser (granulation process).

Then, the polymerizable monomer in the droplets is polymerized to obtain toner base particles (polymerization process).

The polymerization initiator may be mixed when preparing the polymerizable monomer composition, or may be mixed into the polymerizable monomer composition immediately before forming droplets in the aqueous medium.

It can also be added in a dissolved state in the polymerizable monomer or other solvent as necessary during or after the granulation of the droplets, i.e., immediately before starting the polymerization reaction.

After the polymerizable monomer is polymerized to obtain the binder resin, a solvent removal process can be carried out as necessary to obtain a dispersion of the toner base particles.

When the binder resin is obtained by the emulsion aggregation method or the suspension polymerization method, the polymerizable monomer can be any conventionally known monomer without any particular restrictions. Specifically, the vinyl monomers listed in the section on binder resins can be used.

As the polymerization initiator, any known polymerization initiator can be used without any particular restrictions. Specific examples include the following:

Hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid-tert-hydroperoxide, tert-butyl performate, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetic acid, tert-butyl permethoxyacetate, per-N-(3-toluyl)palmitate-tert-butylbenzoyl peroxide, t-butyl Examples of the polymerization initiator include peroxide-based initiators such as butyl peroxy 2-ethylhexanoate, t-butyl peroxy pivalate, t-butyl peroxy isobutyrate, t-butyl peroxy neodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide; and azo- or diazo-based initiators such as 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile.

<Method for Adhering Polyvalent Acid Metal Salt Particles>
Examples of methods for adhering polyvalent acid metal salt particles to toner base particles include a method in which a metal compound serving as a metal source is reacted with a polyvalent acid ion in an aqueous medium in which toner particles are dispersed to obtain polyvalent acid metal salt particles, and a method in which polyvalent acid metal salt particles are adhered to toner particles by mechanical external force in a dry or wet manner.

(1) A method of obtaining a polyvalent acid metal salt by reacting a metal compound serving as a metal source with a polyvalent acid ion in an aqueous medium in which toner base particles are dispersed.

For example, a compound containing a metal element and a polyacid are added to a dispersion of toner base particles and mixed to cause a reaction between the compound containing a metal element and the polyacid, causing the reactant to precipitate. At the same time, the dispersion is stirred to cause the reactant to adhere to the toner base particles.

(2) A method in which polyvalent acid metal salt particles are attached to the surface of toner base particles by mechanical external force, either dry or wet.

For example, a high-speed mixer that applies shear force to powder or aqueous medium, such as an FM Mixer, Mechano Hybrid (manufactured by Nippon Coke & Engineering Co., Ltd.), Super Mixer, Nobilta (manufactured by Hosokawa Micron Corporation), or T.K. Homo Mixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), is used to apply a force that disintegrates the polyvalent acid metal salt particles while causing the polyvalent acid metal salt particles to adhere to the toner base particles.

Among these, a method of obtaining a polyvalent acid metal salt by reacting a metal compound serving as a metal source with a polyvalent acid ion in an aqueous medium in which toner base particles are dispersed is preferred. By using the above method, it is possible to uniformly disperse the polyvalent acid metal salt on the surface of the toner particles. This allows a conductive path to be formed efficiently, and overcharging can be suppressed with fewer polyvalent acid metal salt particles. Furthermore, the uniform dispersion of the polyvalent acid metal salt particles allows the gradient force to act uniformly on the surface of the toner particles, improving solid followability.

When the above method is used, the percentage of polyvalent acid metal salt particles having an area of 100 nm2 or ^less , the percentage of polyvalent acid metal salt particles having an area of 100 nm2 or ^more and 500 ^nm2 or less, the percentage of polyvalent acid metal salt particles having an area of 500 ^nm2 or more, the percentage of the area of polyvalent acid metal salt particles, the average area of polyvalent acid metal salt particles, the coefficient of variation of the area of polyvalent acid metal salt particles, the height of polyvalent acid metal salt particles, and the difficulty of polyvalent acid metal salt particles being removed from the toner mother particles, as observed with a scanning electron microscope, can be easily adjusted to within the range of the present invention.

More specifically, the reaction between the polyacid and the compound containing a metal element can be controlled by the amount of the compound containing a metal element added, the alcohol concentration in the toner base particle dispersion, the temperature, the pH, the addition rate of the compound containing a metal element, and the amount of the organosilicon compound added.

A more preferred method for producing a toner having the configuration of the present invention is to produce polyvalent acid metal salt particles from a compound containing at least one metal element selected from the metal elements contained in groups 3 to 13 and a polyvalent acid in an aqueous medium, and to set the concentration of an alcohol having 1 to 10 carbon atoms in the aqueous medium to 0.0% by mass or more and 0.35% by mass or less. More preferably, it is set to 0.20% by mass or less.

If alcohol is present in the system when polyvalent metal salt particles are generated, the polyvalent metal salt particles and the alcohol form hydrogen bonds in the system, and the polyvalent metal salt particles are stably dispersed in water. This effect is particularly remarkable for polyvalent metal salt particles on the large particle size side. Therefore, if there is a lot of alcohol in the system, it becomes difficult to generate polyvalent metal salt particles with a large particle size. By setting the concentration of the alcohol having 1 to 10 carbon atoms in the system to 0.35 mass% or less, it is possible to increase the number of polyvalent metal salt particles with an area of 500 ^nm2 or ^more while maintaining the number of polyvalent metal salt particles with an area of 100 nm2 or less at a certain level or more.

In addition, according to the above method, the polyvalent acid metal salt particles generated in the aqueous medium are attached to the toner base particles before their growth is complete, so the polyvalent acid metal salt particles are more strongly fixed to the toner base particles than when pre-prepared polyvalent acid metal salt particles are attached by mechanical external force. As a result, the polyvalent acid metal salt particles do not detach from the base particles even during long-term use, and a toner with excellent durability can be obtained that can achieve the effects of the present invention, which are suppression of overcharging and improved solid-color conformability.

It is more preferable to simultaneously introduce an organosilicon compound into the aqueous medium during the reaction of the metal compound with the polyvalent acid ion, and react the organosilicon compound in the aqueous medium to obtain an organosilicon polymer. By using the above method, the polyvalent acid metal salt particles generated in the aqueous medium are firmly fixed to the toner particle surface by the organosilicon polymer before they grow, so that it is possible to further increase the dispersibility of the polyvalent acid metal salt particles. In addition, since the polyvalent acid metal salt particles are firmly fixed to the toner particles by the organosilicon polymer, the effect of improving durability described above is more pronounced. In addition, the area of the interface between the toner base particle and the polyvalent acid metal salt is increased, which promotes the transfer of charges and increases the effect of suppressing overcharging.

The metal compounds, polyacids, and organosilicon compounds used in the above method may be the metal compounds, polyacids, and organosilicon compounds described above.

<Method of attaching organosilicon compound>
The method for adhering the organosilicon compound to the toner base particles will be exemplified below.

The method for attaching the organosilicon compound of the present invention is not particularly limited, and any conventionally known method can be used. For example, a method of condensing the compound shown in the above-mentioned organosilicon compound section in an aqueous medium in which the toner base particles are dispersed, and attaching the organosilicon compound to the toner base particles, or a method of attaching the organosilicon compound to the toner base particles by mechanical external force in a dry or wet manner can be mentioned.

Among these, a method in which the compounds shown in the above section on organosilicon compounds are condensed in an aqueous medium in which the toner base particles are dispersed, and the organosilicon compound is then attached to the toner base particles, is preferred, since this method makes it possible to firmly attach the organosilicon compound to the toner base particles and to uniformly attach the organosilicon compound to the toner base particles.

The above method is explained below.

When the organosilicon compound is attached to the toner base particles by the above method, it is preferable to include a step (step 1) of dispersing the toner base particles in an aqueous medium to obtain a toner base particle dispersion, and a step (step 2) of mixing an organosilicon compound (or a hydrolyzate thereof) with the toner base particle dispersion and adhering the organosilicon compound to the toner base particles by a condensation reaction of the organosilicon compound in the toner base particle dispersion. Furthermore, in order to adjust the amount of alcohol in the toner base particle dispersion involved in the formation of the polyvalent acid metal salt particles, a step (step 3) of removing alcohol from the hydrolyzate of the organosilicon compound may be included as necessary.

In the above step 1, the method of obtaining the toner base particle dispersion may include a method of using the dispersion of toner base particles produced in an aqueous medium as is, and a method of putting dried toner base particles into an aqueous medium and dispersing them mechanically. When dispersing dried toner base particles in an aqueous medium, a dispersion aid may be used.

As the dispersion aid, known dispersion stabilizers and surfactants can be used. Specifically, the dispersion stabilizers include inorganic dispersion stabilizers such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina, and organic dispersion stabilizers such as polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch. In addition, the surfactants include anionic surfactants such as alkyl sulfate ester salts, alkylbenzene sulfonates, and fatty acid salts, nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxypropylene alkyl ethers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. Among them, it is preferable to include an inorganic dispersion stabilizer, and it is more preferable to include a dispersion stabilizer containing a phosphate such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, or aluminum phosphate.

In the above step 2, the organosilicon compound may be added to the toner base particle dispersion liquid as it is, or may be added to the toner base particle dispersion liquid after hydrolysis. Among them, it is preferable to add it after hydrolysis, since the condensation reaction is easy to control and the amount of the organosilicon compound remaining in the toner base particle dispersion liquid can be reduced. The above hydrolysis is preferably carried out in an aqueous medium whose pH is adjusted using a known acid and base. It is known that the hydrolysis of an organosilicon compound is pH-dependent, and it is preferable to change the pH when carrying out the above hydrolysis appropriately depending on the type of organosilicon compound. For example, when methyltriethoxysilane is used as the organosilicon compound, it is preferable that the pH of the above aqueous medium is 2.0 or more and 6.0 or less.

Specific examples of acids for adjusting the pH include inorganic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, hypobromous acid, bromous acid, bromic acid, perbromic acid, hypoiodous acid, iodous acid, iodic acid, periodic acid, sulfuric acid, nitric acid, phosphoric acid, and boric acid, and organic acids such as acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, and tartaric acid.

Specific examples of bases for adjusting the pH include the following: alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, and lithium hydroxide, and their aqueous solutions; alkali metal carbonates such as potassium carbonate, sodium carbonate, and lithium carbonate, and their aqueous solutions; alkali metal sulfates such as potassium sulfate, sodium sulfate, and lithium sulfate, and their aqueous solutions; alkali metal phosphates such as potassium phosphate, sodium phosphate, and lithium phosphate, and their aqueous solutions; alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide, and their aqueous solutions; and amines such as ammonia and triethylamine.

The condensation reaction in step 2 is preferably controlled by adjusting the pH of the toner base particle dispersion. It is known that the condensation reaction of organosilicon compounds is pH-dependent, and it is preferable to change the pH when the condensation reaction is carried out as appropriate depending on the type of organosilicon compound. For example, when methyltriethoxysilane is used as the organosilicon compound, it is preferable that the pH of the aqueous medium is 6.0 or more and 12.0 or less. As the acid and base for adjusting the pH, the acids and bases exemplified in the hydrolysis section above can be used.

The condensation reaction in step 2 is preferably carried out at a temperature of about 10°C or higher and 100°C or lower.

The method used in step 3 above is not particularly limited, and examples of the method include a method of separating the hydrolyzate of the organosilicon compound and the alcohol by vacuum distillation, taking advantage of the difference in boiling points between the hydrolyzate and the alcohol, and a method of separating the alcohol by adsorption onto a porous material such as zeolite that can adsorb the alcohol. Among these, the method of separating the alcohol by vacuum distillation is preferred, since it allows a high degree of freedom in adjusting the alcohol removal conditions and makes it easy to adjust the amount of alcohol removed.

When removing alcohol using the above method, the optimal temperature depends on the organosilicon compound used. For example, when using methyltriethoxysilane, it is preferable to carry out the process at a temperature between 20°C and 50°C in order to simultaneously inhibit condensation of the organosilicon compound and promote the removal of alcohol.

The optimal reduced pressure conditions for the above method depend on the type of organosilicon compound used. For example, when using methyltriethoxysilane, it is preferable to carry out the method at a pressure of -90 kPa or more and -50 kPa or less in order to separate only the alcohol.

Next, the measurement methods used in the present invention will be described in detail below. In the explanation of each measurement method, toner, toner particles, or toner base particles will also be referred to as "toner, etc.".

<Method for observing the surface of toner, etc.>
The surface of the toner, etc. is observed as follows.

The surface of the toner, etc. is observed at a magnification of 50,000 times using a scanning electron microscope (SEM, device name: JSM-7800F manufactured by JEOL Ltd.). Then, the elements on the surface of the toner, etc. are mapped using EDX (energy dispersive X-ray spectroscopy). From the obtained SEM element mapping image, the presence of organic silicon compounds and reaction products between polyacids and compounds containing the above metal elements on the surface of the toner, etc. is confirmed.

Specifically, by comparing the mapping image of the metal element with the mapping image of the element contained in the polyacid (for example, phosphorus when phosphoric acid is used as the polyacid), and finding that the two match, it can be confirmed that the sample contains a reaction product between a compound containing a metal element and a polyacid.

<Methods for calculating the number ratio, area ratio, average area, and coefficient of variation for each area range of polyvalent acid metal salt particles, as well as the number average particle size of organosilicon polymer fine particles and polyvalent acid metal salt fine particles>
The number ratio, area ratio, average area, and coefficient of variation for each area range of the polyvalent acid metal salt particles, as well as the number average particle size of the organosilicon polymer fine particles and polyvalent acid metal salt fine particles, are calculated as follows.

(1) Sample preparation A thin layer of conductive paste (TED PELLA, Inc., Product No. 16053, PELCO Colloidal Graphite, isopropanol base) was applied to a sample stage (aluminum sample stage), and toner or the like was sprayed onto the paste. Excess sample was then removed from the sample stage using air blowing to prepare the sample.

(2) Observation using JSM-7800F SEM images (backscattered electron images) are obtained using the above-mentioned JSM-7800F. The observation conditions are described below.

Start the JSM-7800F's "PC-SEM", insert the sample holder into the sample chamber of the JSM-7800F housing, and move the sample holder to the observation position. On the PC-SEM screen, set the accelerating voltage to [1.0 kV] and the observation magnification to [50,000x]. Press the [ON] button on the observation icon to apply the accelerating voltage and observe the backscattered electron image.

(3) Calculation of the number ratio, area ratio, average area value, and coefficient of variation for each area range of polyvalent acid metal salt particles The obtained backscattered electron image is loaded into the image processing analysis software "ImageJ", and after averaging processing, binarization processing is performed to obtain a binarized image in which the polyvalent acid metal salt particles or the organosilicon polymer particles are displayed in white. The obtained binarized image is then loaded into the image processing analysis software "Image-Pro Plus", and the number ratio, area ratio, average area value, and coefficient of variation for each area range of the polyvalent acid metal salt particles, or the number average particle size of the organosilicon polymer particles and the polyvalent acid metal salt particles are calculated using the built-in function. The above processing is performed for 10 visual fields of the backscattered electron images observed at 50,000 times magnification, and the arithmetic average value of the 10 visual fields is taken as the number ratio, area ratio, average area value, and coefficient of variation for each area range of the polyvalent acid metal salt particles, and the number average particle size of the organosilicon polymer particles and the polyvalent acid metal salt particles.

<Method of measuring height Ha in normal direction of polyvalent acid metal salt particle>
The cross section of the toner, etc. is observed by the following method using a transmission electron microscope (TEM). First, the toner, etc. is thoroughly dispersed in a room temperature curing epoxy resin, and then cured for 2 days in an atmosphere of 40°C. A 100 nm thick flake-shaped sample is cut out from the obtained cured product using a microtome equipped with a diamond blade. This sample is enlarged to 100,000 times with a TEM (product name: electron microscope Tecnai TF20XT, manufactured by FEI), and the cross section of the toner, etc. is observed. In this case, the cross section of the toner, etc. is selected to have a major axis diameter of 0.9 to 1.1 times the number average particle diameter (D1) of the toner, etc. measured according to the measurement method of the number average particle diameter (D1) of the toner, etc. described later.

Next, the constituent elements of the cross-section of the obtained toner, etc. are analyzed using energy dispersive X-ray spectroscopy (EDX) to create an EDX mapping image.

In the EDX mapping image, a signal originating from the polyvalent acid metal salt particles is confirmed on the contour of the cross section of the toner, etc., and the height Ha of the polyvalent acid metal salt particles in the normal direction is calculated.

Using the above method, the cross sections of 50 toner particles are observed, the height (nm) of the polyvalent acid metal salt particles in the normal direction is measured from the image, and the arithmetic average value of the 50 particles is taken as Ha (nm).

<Method of calculating adhesion rate of polyvalent acid metal salt particles in toner, etc.>
The adhesion rate of the polyvalent acid metal salt particles is calculated by the following method.

A process for removing weakly adhered polyvalent acid metal salt particles from a toner, etc. (process (a))
Add 160 g of sucrose (Kishida Chemical Co., Ltd.) to 100 mL of ion-exchanged water, dissolve in a hot water bath, and prepare a 61.5% by mass sucrose aqueous solution. Add 31.0 g of the above sucrose concentrated solution and 6 g of Contaminon N (trade name) (a 10% by mass aqueous solution of a neutral detergent for cleaning precision measuring instruments, pH 7, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) to a centrifuge tube to prepare a dispersion. Add 1.0 g of toner or the like to this dispersion, and break up the clumps of toner or the like with a spatula or the like. Shake the centrifuge tube with a shaker at 300 spm (strokes per minute) for 20 minutes. After shaking, transfer the solution to a glass tube (50 mL) for a swing rotor, and separate it with a centrifuge at 3500 rpm for 30 minutes. It is visually confirmed that the toner, etc. and the aqueous solution are sufficiently separated, and the toner, etc. separated at the top layer is collected with a spatula, etc. The collected toner, etc. is filtered with a vacuum filter and then dried in a dryer for 1 hour or more. The dried product is crushed with a spatula to obtain the toner, etc. (a).

(2) Method for Measuring and Calculating Adhesion Rate The amount of metal originating from polyvalent acid metal salt particles contained in the toner, etc., before and after the above-mentioned treatment (a) is determined by a fluorescent X-ray analyzer.

The detection strength of metals contained in toner, etc. was measured using the following method.

The detection intensity of metals contained in toner, etc. is measured using a wavelength dispersive X-ray fluorescence analyzer "Axios" (manufactured by PANalytical) and the accompanying dedicated software "SuperQ ver. 4.0F" (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data.

Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 27 mm, and the measurement time is 10 seconds.

When measuring light elements, a proportional counter (PC) is used, and when measuring heavy elements, a scintillation counter (SC) is used.

As a measurement sample, 4 g of the toner or the like (a) that has been subjected to the above treatment (a) is placed in a dedicated aluminum ring for pressing and flattened. Then, using a tablet molding compression machine "BRE-32" (manufactured by Maekawa Test Machinery Manufacturing Co., Ltd.), pressure is applied at 20 MPa for 60 seconds to form pellets with a thickness of 2 mm and a diameter of 39 mm. The above operation is also carried out on the toner or the like before the above treatment (a) is formed into pellets. For each sample, the detection intensity (unit: cps) of metal and silicon observed at a diffraction angle (2θ) = 109.08° when pentaerythritol (PET) is used as the analyzing crystal is measured. At this time, the acceleration voltage and current value of the X-ray generator are 24 kV and 100 mA, respectively.

In the X-ray fluorescence analysis, the amount of metal contained in the polyvalent acid metal salt particles before the treatment (a) is M1 (detection intensity kcps), and the amount of metal contained in the polyvalent acid metal salt particles after the treatment (a) is M2 (detection intensity kcps), and the adhesion rate is calculated using the following formula.
Adhesion rate of polyvalent acid metal salt particles = M2/M1

<Method of measuring weight average particle diameter (D4) and number average particle diameter (D1)>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner or the like are calculated as follows.

The measuring device used is a precision particle size distribution measuring device using the electrical resistance method with a 100 μm aperture tube, the Coulter Counter Multisizer 3 (registered trademark, manufactured by Beckman Coulter, Inc.).

The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (Beckman Coulter, Inc.). The measurement is performed using an effective number of measurement channels of 25,000.

The electrolyte solution used for the measurement is made by dissolving special grade sodium chloride in ion-exchanged water to a concentration of 1.0%, for example, "ISOTON II" (manufactured by Beckman Coulter, Inc.).

Before performing measurements and analysis, configure the dedicated software as follows:

On the "Change standard measurement method (SOMME)" screen of the dedicated software, set the total count number in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard particle 10.0 μm" (Beckman Coulter, Inc.). Press the "Threshold/Noise level measurement button" to automatically set the threshold and noise level. Also, set the current to 1,600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement."

In the dedicated software's "Pulse to particle size conversion setting" screen, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) Pour 200.0 mL of the electrolyte solution into a 250 mL round-bottom glass beaker made exclusively for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, remove dirt and air bubbles from inside the aperture tube using the "aperture tube flush" function of the dedicated software.
(2) 30.0 mL of the aqueous electrolyte solution is placed in a 100 mL flat-bottom glass beaker, and 0.3 mL of a dilution of "Contaminon N" (a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments, pH 7, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted 3 times by mass with ion-exchanged water is added as a dispersant.
(3) Prepare an ultrasonic disperser "Ultrasonic Dispersion System Tetra150" (manufactured by Nikkaki Bios Co., Ltd.) that has two built-in oscillators with an oscillation frequency of 50 kHz and a phase shift of 180 degrees and an electrical output of 120 W. Place 3.3 L of ion-exchanged water in the water tank of the ultrasonic disperser, and add 2.0 mL of Contaminon N to this water tank.
(4) The beaker from (2) above 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 surface of the electrolytic solution in the beaker is maximized.
(5) While the electrolyte solution in the beaker in (4) is being irradiated with ultrasonic waves, 10 mg of toner or the like is added little by little to the electrolyte solution and dispersed. Then, ultrasonic dispersion treatment is continued for another 60 seconds. During 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 solution (5) in which the toner or the like is dispersed is dropped into the round-bottom beaker (1) placed in the sample stand, and the measurement concentration is adjusted to 5%. Then, the measurement is continued until the number of particles measured reaches 50,000.
(7) The measurement data is analyzed using the dedicated software that comes with the device to calculate the weight average particle size (D4) and number average particle size (D1). When the dedicated software is set to graph/volume %, the "average diameter" on the "analysis/volume statistics (arithmetic mean)" screen is the weight average particle size (D4). When the dedicated software is set to graph/number %, the "average diameter" on the "analysis/number statistics (arithmetic mean)" screen is the number average particle size (D1).

<Method for measuring alcohol concentration in aqueous medium>
The alcohol concentration in the aqueous medium when the polyvalent acid metal salt particles are formed and when the polyvalent acid metal salt particles are attached to the toner surface is measured by gas chromatography in the following manner.

The polymerization reaction liquid (slurry) is filtered using a membrane filter (e.g., Advantec Toyo Co., Ltd., Disposable Membrane Filter 25JP020AN), and 2 μL of the filtrate is analyzed by gas chromatography. The alcohol concentration in the aqueous medium is then measured using a calibration curve previously prepared using the corresponding alcohol. The analysis was performed under the following conditions.

<Analysis conditions>
GC: HP 6890GC
Column: HP INNOWax (200 μm x 0.40 μm x 50 m)
Carrier gas: He (constant flow mode, initial flow rate: 1.00 ml/min, average linear velocity: 25 cm/sec)
Oven: 50°C: hold for 10 minutes, increase temperature to 200°C at 10°C/minute, hold at 200°C for 5 minutes.
INJ: 200°C, split mode (pressure: 32.8 psi, split flow rate: 30.0 ml/min, total flow rate: 33.5 ml/min)
Split ratio: 30.1:1.0
DET: 250℃ (FID)

The present invention will be described in detail with reference to the following examples. However, these are not intended to limit the present invention in any way. The toner and the method for producing the toner are described below. In the examples and comparative examples, "parts" are all by weight unless otherwise specified.

<Production Example of Toner Base Particle Dispersion>
<Production Example of Toner Base Particle Dispersion 1>
(Preparation of aqueous medium)
14.0 parts of sodium phosphate (12-hydrate) (manufactured by Rasa Kogyo Co., Ltd.) was added to a reaction vessel containing 390.0 parts of ion-exchanged water, and the mixture was kept at 65° C. for 1.0 hours while purging with nitrogen. A calcium chloride aqueous solution in which 9.2 parts of calcium chloride (dihydrate) was dissolved in 10.0 parts of ion-exchanged water was added to the reaction vessel all at once while stirring at 12,000 rpm using a T.K. homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), to prepare an aqueous medium containing a dispersion stabilizer.

Furthermore, 1.0 mol/L of hydrochloric acid was added to the aqueous medium in the reaction vessel to adjust the pH to 6.0, and aqueous medium 1 was prepared.

(Preparation of Polymerizable Monomer Composition)
Styrene 60.0 parts C.I. Pigment Red 122 5.9 parts C.I. Pigment Red 150 3.4 parts The above materials were put into an attritor (manufactured by Nippon Coke & Engineering Co., Ltd.), and further dispersed at 220 rpm for 5.0 hours using zirconia particles having a diameter of 1.7 mm to prepare a colorant dispersion in which the pigment was dispersed.

The following materials were then added to the colorant dispersion:
Styrene 10.0 parts n-Butyl acrylate 30.0 parts Polyester resin 5.0 parts (condensation polymer of terephthalic acid and 2 moles of propylene oxide adduct of bisphenol A)
Fischer-Tropsch wax (melting point 70° C.) 7.0 parts The above materials were kept at 65° C. and uniformly dissolved and dispersed at 500 rpm using a T. K. homomixer to prepare a polymerizable monomer composition.

(Granulation process)
While maintaining the temperature of the aqueous medium 1 at 70° C. and the rotation speed of the stirring device at 12,000 rpm, the polymerizable monomer composition was charged into the aqueous medium 1, and 9.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. Granulation was continued for 10 minutes while maintaining the stirring device at 12,000 rpm.

(Polymerization process)
The high-speed stirring device was changed to a stirrer equipped with a propeller stirring blade, and polymerization was carried out for 5.0 hours while stirring at 150 rpm and maintaining the temperature at 70° C., and then the temperature was raised to 85° C. and heated for 2.0 hours to carry out a polymerization reaction. Ion-exchanged water was added to adjust the toner base particle concentration in the dispersion to 20.0%, and toner base particle dispersion 1 in which toner base particles 1 are dispersed was obtained.

The number average particle size (D1) of toner base particle 1 was 6.0 μm, and the weight average particle size (D4) was 6.4 μm.

<Production Example of Toner Base Particle Dispersion Liquid 2>
(Preparation of Polyester 1)
Into a reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet tube, a dehydration tube, and a pressure reducing device, 85.0 parts of terephthalic acid, 16.4 parts of trimellitic anhydride, 123.3 parts of bisphenol A, and 14.1 parts of ethylene glycol were added and heated to a temperature of 128° C. with stirring.

After adding 0.5 parts of titanium (IV) isopropoxide as an esterification catalyst, the temperature was raised to 158°C and condensation polymerization was carried out over 5 hours. The temperature was then raised to 180°C and the reaction was continued under reduced pressure until the desired molecular weight was reached, yielding polyester 1.

(Preparation of styrene-acrylic resin 1)
Into a reaction vessel equipped with a stirrer, a thermometer, and a nitrogen inlet tube, 80.0 parts of styrene, 20.0 parts of n-butyl acrylate, and 0.3 parts of hexanediol diacrylate were added and heated to a temperature of 80° C. with stirring.

Next, 2.0 parts of Perbutyl O (10-hour half-life temperature 72.1°C (manufactured by Nippon Oil & Fats)) was added as a polymerization initiator, and polymerization was continued for 5 hours to obtain styrene-acrylic resin 1.

(Preparation of Toner Base Particles 2)
・Polyester 1 89.0 parts・Styrene-acrylic resin 1 13.0 parts・C.I. Pigment Blue 15:3 (copper phthalocyanine) 5.2 parts・Ester wax (behenyl behenate: melting point 72 ° C.) 15.0 parts・Fischer-Tropsch wax (Sasol C105, melting point: 105 ° C.) 2.0 parts The above materials were premixed in a Mitsui Henschel mixer (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and then melt-kneaded using a twin-screw extruder (trade name: PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) with the temperature set so that the melt temperature at the discharge port was 140 ° C.

The resulting kneaded material was cooled, coarsely pulverized with a hammer mill, and then finely pulverized with a pulverizer (product name: Turbo Mill T250, manufactured by Turbo Kogyo Co., Ltd.). The resulting finely pulverized powder was classified with a multi-division classifier utilizing the Coanda effect to obtain toner base particles 2.

The number average particle size (D1) of the toner base particles 2 was 5.7 μm, and the weight average particle size (D4) was 6.6 μm.

(Preparation of aqueous medium)
To a reaction vessel containing 390.0 parts of ion-exchanged water, 14.0 parts of sodium phosphate (12-hydrate) (manufactured by Rasa Kogyo Co., Ltd.) were added, and the mixture was kept at 65° C. for 1.0 hour while being purged with nitrogen.

A calcium chloride aqueous solution containing 9.2 parts of calcium chloride (dihydrate) dissolved in 10.0 parts of ion-exchanged water was added all at once to a reaction vessel while stirring at 12,000 rpm using a T.K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare an aqueous medium containing a dispersion stabilizer.

Furthermore, 1.0 mol/L of hydrochloric acid was added to the aqueous medium in the reaction vessel to adjust the pH to 6.0, and the aqueous medium was prepared.

(Preparation of Toner Base Particle Dispersion 2)
200.0 parts of toner base particles 2 were added to the aqueous medium and dispersed for 15 minutes while rotating at 5000 rpm using a T.K. homomixer at a temperature of 60° C. Ion-exchanged water was added to adjust the toner particle concentration in the dispersion to 20.0%, thereby obtaining toner base particle dispersion 2.

<Production Example of Toner Base Particle Dispersion 3>
(Preparation of Resin Particle Dispersion)
The following materials were weighed, mixed and dissolved:
To this solution, a 10% aqueous solution of NEOGEN RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added and dispersed. An aqueous solution of 0.15 parts of potassium persulfate dissolved in 10.0 parts of ion-exchanged water was added while slowly stirring for another 10 minutes.

After replacing the atmosphere with nitrogen, emulsion polymerization was carried out at a temperature of 70°C for 6.0 hours. After polymerization was completed, the reaction liquid was cooled to room temperature, and ion-exchanged water was added to obtain a resin particle dispersion with a solid content of 12.5% and a number-average particle size of 0.2 μm.

(Preparation of Colorant Particle Dispersion)
The following materials were weighed and mixed:
Ester wax (melting point 70° C.) 100.0 parts Neogen RK 15.0 parts Ion-exchanged water 385.0 parts Dispersed for 1 hour using a wet jet mill JN100 (manufactured by Jokou Co., Ltd.) to obtain a wax particle dispersion. The solid content concentration of the wax particle dispersion was 20.0%.

The following materials were weighed and mixed:
・C.I. Pigment Red 122 62.6 parts ・C.I. Pigment Red 150 37.4 parts ・Neogen RK 15.0 parts ・Ion-exchanged water 885.0 parts Dispersed for 1 hour using a wet jet mill JN100 to obtain a colorant particle dispersion. The solid content concentration of the colorant particle dispersion was 10.0%.

(Preparation of Toner Base Particles 3)
Resin particle dispersion 160.0 parts Wax particle dispersion 10.0 parts Colorant particle dispersion 18.9 parts Magnesium sulfate 0.2 parts The above materials were dispersed using a homogenizer (IKA Co., Ltd.), and then heated to 65°C while stirring. After stirring at 65°C for 1.0 hour, it was confirmed that aggregate particles with a number average particle size of 5.9 μm were formed when observed with an optical microscope. After adding 2.2 parts of NEOGEN RK (Dai-ichi Kogyo Seiyaku Co., Ltd.), the temperature was raised to 80°C and stirred for 2.0 hours to obtain fused colored resin particles.

After cooling, the mixture was filtered, and the filtered solid was washed with 720.0 parts of ion-exchanged water by stirring for 1.0 hour. The dispersion liquid containing the colored resin was filtered and then dried to obtain toner base particles 3.

The number average particle size (D1) of the toner base particles 3 was 6.1 μm, and the weight average particle size (D4) was 7.0 μm.

(Preparation of aqueous medium)
To a reaction vessel containing 390.0 parts of ion-exchanged water, 14.0 parts of sodium phosphate (12-hydrate) (manufactured by Rasa Kogyo Co., Ltd.) were added, and the mixture was kept at 65° C. for 1.0 hour while being purged with nitrogen.

A calcium chloride aqueous solution containing 9.2 parts of calcium chloride (dihydrate) dissolved in 10.0 parts of ion-exchanged water was added all at once while stirring at 12,000 rpm using a T.K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare an aqueous medium containing a dispersion stabilizer.

Furthermore, 1.0 mol/L of hydrochloric acid was added to the aqueous medium in the reaction vessel to adjust the pH to 6.0, and the aqueous medium was prepared.

(Preparation of Toner Base Particle Dispersion 3)
100.0 parts of toner base particles 3 were added to the aqueous medium and dispersed for 15 minutes while rotating at 5000 rpm using a T.K. homomixer at a temperature of 60° C. Ion-exchanged water was added to adjust the solid content of toner base particles 3 in the dispersion to 20.0%, thereby obtaining toner base particle dispersion 3.

<Production Example of Toner Base Particle Dispersion Liquid 4>
(Preparation of emulsified slurry)
660.0 parts of ion-exchanged water and 25.0 parts of a 48.5% aqueous solution of sodium dodecyldiphenyletherdisulfonate were mixed and stirred at 10,000 rpm using a T. K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare an aqueous medium.

The following materials were added to 500.0 parts of ethyl acetate and dissolved at 100 rpm using a propeller stirrer to prepare a solution.
Styrene/butyl acrylate copolymer 100.0 parts (copolymerization mass ratio: 80/20)
Polyester resin 3.0 parts (condensation polymer of terephthalic acid and 2 moles of propylene oxide adduct of bisphenol A)
C.I. Pigment Red 122 6.1 parts C.I. Pigment Red 150 3.5 parts Fischer-Tropsch wax (melting point 70°C) 9.0 parts

Next, 150.0 parts of the aqueous medium was placed in a container and stirred at 12,000 rpm using a T.K. homogenizer, and 100.0 parts of the dissolving solution was added thereto and mixed for 10 minutes to prepare an emulsified slurry.

(Preparation of Toner Base Particles 4)
Thereafter, 100.0 parts of the emulsified slurry was placed in a flask equipped with a degassing pipe, a stirrer, and a thermometer, and the solvent was removed under reduced pressure at 30° C. for 12 hours while stirring at a peripheral speed of 20 m/min, and then aged at 45° C. for 4 hours to obtain a solvent-free slurry.

After the solvent-free slurry was filtered under reduced pressure, 300.0 parts of ion-exchanged water was added to the resulting filter cake, which was then mixed and redispersed in a T.K. homogenizer (at 12,000 rpm for 10 minutes) and filtered.

The resulting filter cake was dried in a dryer at 45°C for 48 hours, and sieved through a 75 μm mesh to obtain toner base particles 4.

The number average particle size (D1) of the toner base particles 4 was 5.6 μm, and the weight average particle size (D4) was 6.8 μm.

(Preparation of aqueous medium)
To a reaction vessel containing 390.0 parts of ion-exchanged water, 14.0 parts of sodium phosphate (12-hydrate) (manufactured by Rasa Kogyo Co., Ltd.) were added, and the mixture was kept at 65° C. for 1.0 hour while being purged with nitrogen.

A calcium chloride aqueous solution in which 9.2 parts of calcium chloride (dihydrate) was dissolved in 10.0 parts of ion-exchanged water was added all at once while stirring at 12,000 rpm using a T.K. homomixer to prepare an aqueous medium containing a dispersion stabilizer. Furthermore, 1.0 mol/L of hydrochloric acid was added to the aqueous medium to adjust the pH to 6.0, and an aqueous medium was prepared.

(Preparation of Toner Base Particle Dispersion 4)
100.0 parts of toner base particles 4 were added to the aqueous medium and dispersed for 15 minutes while rotating at 5000 rpm using a T.K. homomixer at a temperature of 60° C. Ion-exchanged water was added to adjust the solid content of toner base particles 4 in the dispersion to 20.0%, thereby obtaining toner base particle dispersion 4.

<Production Example of Organosilicon Compound Liquid>
<Production Examples of Organosilicon Compound Liquids 1 and 2>
70.0 parts of ion-exchanged water 30.0 parts of methyltriethoxysilane The above materials were weighed into a 200 mL beaker, and the pH was adjusted to 3.5 with 10% hydrochloric acid. Then, the mixture was stirred for 1.0 hours while adjusting the temperature to 30° C. in a water bath to produce organosilicon compound liquid 1. Then, the organosilicon compound liquid 1 produced was subjected to reduced pressure distillation for 2.0 hours under conditions of 40° C. and −90 kPa, and organosilicon compound liquid 2 was obtained by removing a portion of the ethanol contained in organosilicon compound liquid 1.

<Production Example of Organosilicon Compound Liquid 3>
The above materials were mixed, and 1.0 mol/L of hydrochloric acid was added to adjust the pH to 4.0. After that, the mixture was heated to 60° C. in a water bath and stirred for 1 hour to prepare organosilicon compound liquid 3.

<Production Example of Organosilicon Compound Particles>
<Production Example of Organosilicon Polymer Particles 1>
1620 parts of water was placed in a vessel equipped with a stirrer and heated to 70°C in a warm bath, after which 1.0 mol/L sodium hydroxide solution was added to adjust the pH to 9.0. 33.0 parts of the above organosilicon compound liquid 1 was added thereto over 1 hour, and condensation polymerization was carried out for 1 hour while maintaining the temperature at 70°C. Thereafter, 0.1 mol/L sodium hydroxide solution was gradually added to adjust the pH to 10.5, and condensation polymerization was carried out at 70°C for another 3 hours to obtain a dispersion of organosilicon polymer particles 1.

The resulting dispersion of organosilicon polymer microparticles 1 was centrifuged to remove coarse particles, then filtered, washed and dried to obtain organosilicon polymer microparticles 1.

The number average particle size of organosilicon polymer particles 1 was 30 nm.

<Production Example of Polyvalent Acid Metal Salt Particles>
<Polyvalent acid metal salt particles 1>
Ion-exchanged water 100.0 parts Sodium phosphate (12-hydrate) [Rasa Kogyo Co., Ltd.] 8.5 parts After mixing the above, 16.0 parts (corresponding to 7.0 parts of titanium lactate) of 44% aqueous solution (TC-310: Matsumoto Fine Chemical Co., Ltd.) was added while stirring at 12,000 rpm using a T.K. homomixer (Tokushu Kika Kogyo Co., Ltd.) at 85°C. 1 mol/L hydrochloric acid was added to adjust the pH to 7.5.

Then, the solids were extracted by centrifugation. Next, the process of dispersing again in ion-exchanged water and extracting the solids by centrifugation was repeated three times to remove ions such as sodium. The particles were dispersed again in ion-exchanged water and dried by spray drying to obtain titanium phosphate compound microparticles with a number-average particle size of 8.0 nm, which were designated as polyvalent acid metal salt particles 1.

<Polyvalent acid metal salt particles 2>
Polyvalent acid metal salt particles 2 having a number average particle size of 166 nm were obtained in the same manner as in Production Example 1 of polyvalent acid metal salt particles 1, except that the temperature was changed to 40°C.

<Polyvalent acid metal salt particles 3>
Polyvalent acid metal salt particles 3 having a number average particle size of 18.5 nm were obtained in the same manner as in Production Example 1 of Polyvalent acid metal salt particles 1, except that the temperature was changed to 60°C.

<Toner manufacturing example>
<Production Example of Toner 1>
500.0 parts of toner base particle dispersion 1 was weighed out and placed in a reaction vessel, and stirred using a propeller stirring blade.

Next, 1.0 mol/L hydrochloric acid was added to adjust the pH of the mixed solution to 5.5, and immediately after that, 8.0 parts of organosilicon compound liquid 2 was added, and then ethanol (Kishida Chemical Co., Ltd.) was added so that the ethanol concentration of the mixed solution was 0.02 mass%. After that, the pH was adjusted to 9.5 using 1.0 mol/L aqueous NaOH solution.

Next, the temperature of the mixed solution was raised to 55° C., and the following materials were then added to the mixed solution all at once.
Titanium lactate 44% aqueous solution 2.44 parts (TC-310: Matsumoto Fine Chemical Co., Ltd., equivalent to 1.07 parts as titanium lactate)

The mixture was then held for 1 hour while mixing using a propeller agitator. The pH was then adjusted to 9.5 using a 1.0 mol/L NaOH aqueous solution, and the mixture was held at 55°C while stirring for 2 hours.

After lowering the temperature to 25°C, the pH was adjusted to 1.5 with 1.0 mol/L hydrochloric acid and stirred for 1 hour, after which the mixture was washed with ion-exchanged water and filtered to obtain toner particles 1. This was named toner 1.

As a result of the analysis, it was confirmed that Toner 1 has a reaction product (in the form of fine particles) of phosphoric acid and a compound containing titanium, and an organosilicon compound on its surface.

In the reflected electron image of the toner, the percentage of the number of the polyvalent metal salt particles having an area of 100 ^nm2 or less to the total number of the polyvalent metal salt particles was 86.2%, and the percentage of the number of the polyvalent metal salt particles having an area of 500 ^nm2 or more was 9.8%. Furthermore, in the reflected electron image, the percentage of the area of the polyvalent metal salt particles having an area of 100 ^nm2 or less to the total area of the toner particle surface in the observed field of view was 3.6%.

The reaction product of the phosphoric acid and the titanium-containing compound is a reaction product of titanium lactate (a titanium-containing compound) and sodium phosphate in an aqueous medium or phosphate ions (polyacid) derived from calcium phosphate.

<Production Examples of Toners 5 to 29 and 32 to 36>
Toner particles 5 to 29 and 32 to 36 were obtained by changing the production conditions in the production example of toner 1 to those shown in Table 1. Toner particles 5 to 29 and 32 to 36 were used as toners 5 to 29 and 32 to 36.

<Production Example of Toner 3>
The following materials were weighed and placed in a reaction vessel, and stirred using a propeller stirring blade.
Toner base particle dispersion 1 500.0 parts Organosilicon polymer particles 1 3.0 parts

Next, ethanol (Kishida Chemical Co., Ltd.) was added so that the ethanol concentration of the mixed solution was 0.02% by mass. The pH was then adjusted to 9.5 using a 1.0 mol/L NaOH aqueous solution.

Next, the temperature of the mixed solution was raised to 55° C., and the following materials were then added to the mixed solution all at once.
Titanium lactate 44% aqueous solution 2.44 parts (TC-310: Matsumoto Fine Chemical Co., Ltd., equivalent to 1.07 parts as titanium lactate)

The mixture was then held for 1 hour while mixing using a propeller agitator. The pH was then adjusted to 9.5 using a 1.0 mol/L NaOH aqueous solution, and the mixture was held at 55°C while stirring for 2 hours.

After lowering the temperature to 25°C, the pH was adjusted to 1.5 with 1.0 mol/L hydrochloric acid and stirred for 1 hour, and then the mixture was washed with ion-exchanged water and filtered to obtain toner particles 3. This was named toner 3.

<Production Example of Toner 4>
500.0 parts of toner base particle dispersion 1 was weighed out and placed in a reaction vessel, and stirred using a propeller stirring blade.

Next, 1.0 mol/L hydrochloric acid was added to adjust the pH of the mixed solution to 5.5, and immediately thereafter 8.0 parts of the organosilicon compound liquid 2 was added. Then, the pH was adjusted to 9.5 using 1.0 mol/L aqueous NaOH solution. Immediately after adjusting the pH, the following materials were added to the mixed solution.
Polyvalent acid metal salt particles 1 0.43 parts Polyvalent acid metal salt particles 2 0.05 parts Polyvalent acid metal salt particles 3 0.02 parts

The temperature of the mixture was then raised to 55°C and held for 1 hour while mixing using a propeller stirring blade. The pH was then adjusted to 9.5 using a 1.0 mol/L NaOH aqueous solution, and the temperature was held at 55°C while stirring for 2 hours.

After lowering the temperature to 25°C, the pH was adjusted to 1.5 with 1.0 mol/L hydrochloric acid and stirred for 1 hour, after which the mixture was washed with ion-exchanged water and filtered to obtain toner particles 4. This was named toner 4.

<Production Example of Toner 30>
In the production example of toner 4, the type and number of parts of the polyvalent acid metal salt particles to be added were changed as follows to obtain toner particles 30. Toner particles 30 are designated as toner 30.
Polyvalent acid metal salt particles 1 0.42 parts Polyvalent acid metal salt particles 2 0.08 parts

<Production Example of Toner 31>
In the production example of toner 4, the amount of the polyvalent acid metal salt fine particles to be added was changed to the following parts to obtain toner particles 31. Toner particles 31 are designated as toner 31.
Polyvalent acid metal salt particles 1 0.49 parts Polyvalent acid metal salt particles 2 0.01 parts Polyvalent acid metal salt particles 3 0.002 parts

<Production Example of Toner 2>
500.0 parts of toner base particle dispersion 1 was weighed out and placed in a reaction vessel, and stirred using a propeller stirring blade.

Next, 1.0 mol/L hydrochloric acid was added to adjust the pH of the mixed solution to 5.5, and immediately thereafter 8.0 parts of organosilicon compound liquid 2 was added. After that, the pH was adjusted to 9.5 using 1.0 mol/L aqueous NaOH solution.

The temperature of the mixture was then raised to 55°C and held for 1 hour while mixing using a propeller stirring blade. The pH was then adjusted to 9.5 using a 1.0 mol/L NaOH aqueous solution, and the temperature was held at 55°C while stirring for 2 hours.

After the temperature was lowered to 25° C., the pH was adjusted to 1.5 with 1.0 mol/L hydrochloric acid and stirred for 1 hour, and then the mixture was washed with ion-exchanged water and filtered to obtain toner particles 2. Thereafter, the following materials were charged into a SUPERMIXER PICCOLO SMP-2 (manufactured by Kawata Corporation).
Toner particles 2 100.0 parts Polyvalent acid metal salt particles 1 0.43 parts Polyvalent acid metal salt particles 2 0.05 parts Polyvalent acid metal salt particles 3 0.02 parts

After mixing at 3000 rpm for 20 minutes, the mixture was sieved through a 150 μm mesh to obtain Toner 2.

Comparative toner manufacturing example
<Production Example of Comparative Toner 1>
The toner base particle dispersion liquid 1 was filtered and dried to obtain the toner base particles 1 which were taken out and used as they are as toner particles 37 .

The above materials were put into a SUPERMIXER PICCOLO SMP-2 (manufactured by Kawata Corporation) and mixed at 3000 rpm for 20 minutes. The mixture was then sieved through a 150 μm mesh to obtain a comparative toner 1.

<Production Examples of Comparative Toners 2 to 5>
In the production example of toner 1, the production conditions were changed to those shown in Table 2 to produce toner particles 38 to 41, which were used as comparative toners 2 to 5.

<Production Example of Comparative Toner 6>
The following materials were weighed and placed in a reaction vessel and mixed using a propeller stirring blade.
Titanium lactate 44% aqueous solution 0.75 parts (TC-310: Matsumoto Fine Chemical Co., Ltd., equivalent to 0.33 parts of titanium lactate)
Toner base particle dispersion 1 500.0 parts

Next, 1.0 mol/L hydrochloric acid was added to adjust the pH of the mixed solution to 5.5, and immediately thereafter 20.0 parts of organosilicon compound liquid 3 was added, and the pH was adjusted to 7.0 using 1.0 mol/L aqueous NaOH solution.

The temperature of the mixture was raised to 50°C, and the mixture was held for 1 hour while being mixed using a propeller stirring blade. The pH was then adjusted to 9.5 using a 1.0 mol/L NaOH aqueous solution, and the temperature was kept at 50°C while being stirred for 2 hours.

After lowering the temperature to 25°C, the pH was adjusted to 1.5 with 1.0 mol/L hydrochloric acid and stirred for 1 hour, and then the mixture was washed with ion-exchanged water and filtered to obtain toner particles 42. This was designated comparative toner 6.

Comparative toner 6 had a high ethanol concentration of 0.35% in the polyvalent acid metal salt particle production system, and therefore the percentage of the number of produced polyvalent acid metal salt particles having an area of 500 nm ² or more was low at 1.2%.

The physical properties of toners 1 to 36 and comparative toners 1 to 6 are shown in Table 3.

The symbols (A) to (L) in Table 3 represent the following:
(A) Metal element contained in polyvalent acid metal salt particles (B) Polyvalent acid contained in polyvalent acid metal salt particles (C) Proportion (%) of polyvalent acid metal salt particles with an area of 100 ^nm2 or less
(D) The percentage of polyvalent acid metal salt particles with an area of 500 ^nm2 or more (%)
(E) The ratio (%) of the area of the polyvalent acid metal salt particles having an area of 100 ^nm2 or less
(F) The percentage of polyvalent acid metal salt particles with an area of 100 ^nm2 or more and 500 ^nm2 or less (%)
(G) Average area of polyvalent acid metal salt particles (nm ² )
(H) Coefficient of variation of the area of polyvalent acid metal salt particles (I) Proportion (%) of the area of polyvalent acid metal salt particles
(J) The average height Ha (nm) of the polyvalent acid metal salt particles in the normal direction
(K) Adhesion rate M2/M1
(L) Presence or absence of an organosilicon compound on the surface of toner particles

[Examples 1 to 36, Comparative Examples 1 to 6]
The above toners 1 to 36 and comparative toners 1 to 6 were evaluated by the methods described below. The evaluation results are shown in Table 4.

The evaluation method and evaluation criteria of the present invention are explained below.

<Evaluation of solid color conformity>
A modified version of a commercially available Canon laser beam printer, "LBP7600C," was used.

The modification was that the gears and software of the evaluation machine were changed to set the rotation speed of the developing roller to rotate at 2.2 times the peripheral speed of the drum. Furthermore, the toner supply roller was removed. 40 g of toner was loaded into the toner cartridge of the LBP7600C. Under normal temperature and humidity conditions (temperature 25°C/relative humidity 50%), five full solid images were printed on Business 4200 paper (manufactured by XEROX, 75 g/ ^m2 ) of LETTER size.

All solid images obtained were evaluated for solid tracking ability.

The image density was measured using a Macbeth Reflection Densitometer RD918 (Macbeth) in accordance with the attached instruction manual by measuring the relative density of the image in the white background area where the image density was 0.00, and the obtained relative density was used as the image density value.

(Evaluation criteria for solid tracking ability)
The evaluation was made based on the difference between the image density at the leading edge of the first full solid image and the image density at the trailing edge of the third full solid image.
A: The difference between the image density of the leading edge of the first solid image and the image density of the trailing edge of the third solid image is less than 0.10. B: The difference between the image density of the leading edge of the first solid image and the image density of the trailing edge of the third solid image is 0.10 or more and less than 0.20. C: The difference between the image density of the leading edge of the first solid image and the image density of the trailing edge of the third solid image is 0.20 or more and less than 0.30. D: The difference between the image density of the leading edge of the first solid image and the image density of the trailing edge of the third solid image is 0.30 or more.

<Evaluation of suppression of excessive charging>
As the image forming apparatus, the following modified laser printer and process cartridge were used.
- A commercially available laser printer LBP-7700C (manufactured by Canon Inc.) modified to have a process speed of 250 mm/sec. - A commercially available process cartridge, Toner Cartridge 323 (black) (manufactured by Canon Inc.)
The product toner was removed from the inside of the cartridge, and after cleaning with an air blower, 150 g of the toner to be evaluated was filled in. In each station for yellow, magenta, and cyan, the product toner was removed, and the yellow, magenta, and cyan cartridges with the toner remaining amount detection mechanism disabled were inserted and evaluated.

The above process cartridge, the above modified laser printer, and the following transfer paper were left to stand for 48 hours in a low temperature and low humidity environment (temperature 0° C./relative humidity 10%).
Transfer paper: GF-C081 (Canon Inc., A4: 81.4 g/m ² )
In a low temperature environment, 10,000 images with a printing rate of 0.5% were continuously output on transfer paper. Then, one halftone image with a loading amount of 0.20 mg/ ^cm2 was output, and the image was visually observed to check for unevenness in density. At the same time, the surface of the developing roller was visually observed to check the state of the toner layer on the developing roller. The performance of suppressing overcharging was evaluated based on the following evaluation criteria.

Overcharging is likely to occur in low temperature and low humidity environments. When overcharging occurs, the adhesion between the toner and the developing roller increases, making it difficult to regulate with the regulating blade. This can lead to a thicker toner layer on the developing roller, resulting in uneven density in the image. In the case of a toner that excels at suppressing overcharging, it is possible to obtain a good image even under the above conditions.

(Evaluation Criteria for Suppression of Excessive Charging)
A: The toner layer on the developing roller is uniform, and the image has no uneven density. The toner layer is excellent in suppressing overcharging.
B: The toner layer on the developing roller is slightly thicker at the edges, but the image has no uneven density. Excellent suppression of overcharging.
C: The toner layer on the developing roller is somewhat uneven overall, but the image has no density unevenness.
D: The toner layer on the developing roller is somewhat uneven overall, and minute density unevenness occurs at the edges of the image.

<Evaluation of durability>
After the evaluation of the solid-color tracking ability, 30,000 sheets of images with a printing ratio of 1.0% were continuously printed on evaluation paper in a normal temperature and humidity environment (temperature 25° C./relative humidity 50%). After leaving the paper to stand for 24 hours in the same environment, the entire solid-color image was evaluated in the same manner as in the evaluation of the solid-color tracking ability.

Evaluation was performed according to the evaluation criteria for solid print conformity described above, and durability was evaluated based on the following criteria by comparing the image density difference before and after durability testing.

(Durability evaluation criteria)
A: The change in image density difference before and after durability is less than 0.05. B: The change in image density difference before and after durability is 0.05 or more and less than 0.10. C: The change in image density difference before and after durability is 0.10 or more and less than 0.20. D: The change in image density difference before and after durability is 0.20 or more.

The developing roller was also visually observed to check for contamination with metal compound particles such as polyvalent acid metal salt particles.

(Contamination assessment criteria)
A: No contamination occurred up to 30,000 sheets.
B: Slight contamination occurred after 30,000 sheets.
C: Contamination occurred after 30,000 sheets, to a degree that does not cause any practical problems.
D: Ugly contamination occurred after 30,000 sheets.

<Evaluation of low temperature fixability>
Under normal temperature and humidity conditions (temperature 25°C/relative humidity 50%), an LBP7600C modified to adjust the fixing temperature was used, and the fixing temperature was changed in 5°C increments from 140°C at a process speed of 290 mm/sec. For the toner to be evaluated, a solid image with a toner loading of 0.40 mg/ ^cm2 was formed on a Letter-sized Business 4200 paper (manufactured by Xerox Corporation, 75 g/ ^m2 ), and a fixed image was formed by heating and pressing in an oil-free manner. Using a Kimwipe (S-200, manufactured by Crecia Corporation), the fixed image was rubbed 10 times under a load of 7.35 kPa (75 g/ ^cm2 ), and the temperature at which the image density reduction rate before and after rubbing was less than 5% was defined as the fixing temperature, and evaluation was performed based on the following criteria. The image density was measured using a color reflection densitometer X-RITE 404A (manufactured by X-Rite Co.) to measure the relative density of a printout image of a white background portion with an original density of 0.00, and the rate of decrease in image density after rubbing was calculated.

(Evaluation Criteria for Low Temperature Fixability)
A: Less than 150°C B: 150°C or more and less than 160°C C: 160°C or more and less than 170°C D: 170°C or more

Claims (10)

A toner having toner particles containing a binder resin,
polyvalent acid metal salt particles of a polyvalent acid and a compound containing at least one metal element selected from the metal elements included in Groups 3 to 13 are present on the surface of the toner particles,
In a reflected electron image of the toner taken at a magnification of 50,000 times using a scanning electron microscope, when the percentage of the number of the polyvalent acid metal salt particles having an area of 100 ^nm2 or less to the total number of the polyvalent acid metal salt particles is A and the percentage of the number of the polyvalent acid metal salt particles having an area of 500 ^nm2 or more is B, the following formulae (1) and (2) are satisfied:
83.0≦A (1)
1.7≦B≦17.0 (2)
A toner characterized in that in the reflected electron image, the ratio of the area of the polyvalent acid metal salt particles having an area of 100 nm2 or ^less to the total area of the toner particle surface in the observed field of view is 0.3% or more and 16.0% or less. When the ratio (%) of the number of the polyvalent acid metal salt particles having an area of 100 ^nm2 or more and 500 nm2 or less to the total number of the polyvalent acid metal salt particles in a reflected electron image of the toner taken at a magnification of 50,000 ^times using a scanning electron microscope is defined as C,
The toner according to claim 1 , which satisfies the following formula (3):
3.0<C≦15.3 (3) 3. The toner according to claim 1, wherein the average area of the polyvalent acid metal salt particles is from 10 ^nm2 to 5,000 ^nm2 . The toner according to any one of claims 1 to 3, wherein the coefficient of variation of the area of the polyvalent acid metal salt particles is 10.0 or less. The toner according to any one of claims 1 to 4, wherein in a backscattered electron image of the toner taken with a scanning electron microscope at a magnification of 50,000 times, the ratio of the area of the polyvalent acid metal salt particles to the total area of the toner particle surface in the observed field of view is 1.1% to 26.3%. The toner according to any one of claims 1 to 5, wherein, in a mapping analysis using an energy dispersive X-ray spectrometer (EDS) on a cross section of the toner particle observed with a transmission electron microscope (TEM), when an average value of height in a normal direction of the polyvalent acid metal salt particle is taken as Ha (nm), the following formula (4) is satisfied:
2.5≦Ha≦50.0 (4) The metal element contained in the polyvalent acid metal salt particles is designated as metal element M,
The amount of metal element M contained in the toner determined by fluorescent X-ray analysis is defined as M1 (detection intensity kcps),
1.0 g of the toner was dispersed in a mixed aqueous solution consisting of 31.0 g of a 61.5% by mass sucrose aqueous solution and 6.0 g of a 10% by mass neutral detergent aqueous solution for cleaning precision measuring instruments, which is composed of a nonionic surfactant, an anionic surfactant and an organic builder, and the dispersion was subjected to a process (a) in which the dispersion was shaken for 20 minutes at 300 times per minute using a shaker. The toner thus obtained was designated as toner (a);
The amount of metal element M contained in the toner (a) determined by fluorescent X-ray analysis is M2 (detection intensity kcps).
When
The toner according to any one of claims 1 to 6, wherein M1 and M2 satisfy the following formula (5):
0.85≦M2/M1 (5) The toner according to any one of claims 1 to 7, wherein the toner particles have an organosilicon compound on the surface. The toner according to any one of claims 1 to 8, wherein the metal element is at least one selected from the group consisting of titanium, zirconium, copper, and aluminum. A method for producing the toner according to any one of claims 1 to 9,
A method for producing a toner, comprising the steps of: generating polyvalent acid metal salt particles of a polyvalent acid and a compound containing at least one metal element selected from the metal elements in Groups 3 to 13 of the toner; by reacting the compound containing the metal element with a polyvalent acid in an aqueous medium containing toner base particles and an organosilicon compound.