JP7337538B2 - toner - Google Patents

Description

The present invention relates to toners used in image forming methods such as electrophotography.

In electrophotographic image forming apparatuses, user demands for higher speed, higher image quality, and longer life are increasing more and more.
In addition, it is required to demonstrate stable performance even in a wide variety of usage environments and media used by users around the world. It is
Among them, monochrome printers are often used in small offices without air conditioning equipment, and there is a demand for stable performance in a wide range of usage environments, from low temperature and low humidity environments to high temperature and high humidity environments. .
In addition, as users become more environmentally conscious and use environments diversify, the number of cases where rough paper with rougher surfaces such as recycled paper and thin paper is used is increasing. When rough paper is used, the image quality of halftone images tends to be lower than when paper with high smoothness is used, and there is a demand for even higher image quality.

In response to such requests, sensors such as environmental sensors and media detection sensors are installed in the system of the main body, and each electrophotographic process is controlled to the optimum settings according to the usage environment, the number of durable sheets, and the media used. By doing so, a certain improvement effect can be obtained. However, there are concerns that an increase in the number of parts will affect the main body size, power consumption, and increase in wait time.
Therefore, there is a demand for a toner that can be used in a wide range of environments and media and that can stabilize image quality through long-term use.
For example, Patent Document 1 proposes a magnetic toner having magnetic toner particles containing magnetic particles whose moisture adsorption properties are controlled. Using this technique has a certain effect on image quality improvement in a high-temperature and high-humidity environment.
Further, Patent Document 2 proposes to improve the transferability when left in a hot and humid environment for a long period of time by containing a specific polyester resin and a hydrophobized magnetic material.

JP 2006-133734 A JP 2015-227929 A

According to the studies of the present inventors, it has been found that there is room for improvement in the image quality of halftone images when printing on rough paper in a low-temperature, low-humidity environment or in a high-temperature, high-humidity environment.
In a low-temperature, low-humidity environment, when outputting an image that contains a mixture of solid areas with a high print rate and halftone areas with a low print rate, density differences occur depending on the position of the halftone areas, resulting in poor uniformity. It was found to decrease (hereinafter sometimes simply referred to as density uniformity).
On the other hand, we found that when printing on rough paper in a high-temperature, high-humidity environment, some dots in the halftone image may be missing and dot reproducibility may be degraded (hereinafter simply referred to as dot reproducibility sometimes referred to as).
It was also found that there is room for improvement in the density retention rate of halftone images in long-term use (hereinafter sometimes simply referred to as density retention rate).

In the above patent document, when an image is output using rough paper, there is room for improvement in terms of halftone density uniformity in a low temperature and low humidity environment, dot reproducibility in a high temperature and high humidity environment, and density retention rate in long-term use. .
As described above, when an image is output using rough paper, there is a demand for a toner that provides good image quality of halftone images through long-term use in a wide range of environments, but there is still room for improvement.
SUMMARY OF THE INVENTION An object of the present invention is to provide a toner free from the above problems.
Specifically, when outputting an image using rough paper, we provide a toner that has halftone density uniformity in a low-temperature, low-humidity environment, dot reproducibility in a high-temperature, high-humidity environment, and a good density retention rate in long-term use. do.

（式（４）中、ｍ＋ｎは２以上の整数であり、Ｒ _１ 及びＲ _４ は独立してＨ又はＣＨ _３ を表し、Ｒ _２ 及びＲ _３ は独立して炭素数２以上１２以下の直鎖又は分岐鎖を有する炭化水素基を表す。）
該磁性体が、疎水化処理剤によって処理された疎水化処理磁性体であり、
該疎水化処理剤が下記の式（Ｉ）で示される、アルキルトリアルコキシシランカップリング剤を含有し、
Ｃ _ｐ Ｈ _２ｐ＋１ －Ｓｉ－（ＯＣ _ｑ Ｈ _２ｑ＋１ ） _３ （Ｉ）
（式（Ｉ）中、ｐは８以上１６以下の整数を示し、ｑは１以上３以下の整数を示す。）
該磁性体の蒸気吸着量測定で得た水分吸脱着曲線において下記（１）及び（２）を満たし、
（１） １．７≦Ｚ≦６．０
（２） Ｙ－Ｘ≧０．１０
Ｘ：吸着曲線における３０℃相対湿度１０％での水分吸着量（ｍｇ／ｇ）
Ｙ：脱着曲線における３０℃相対湿度１０％での水分吸着量（ｍｇ／ｇ）
Ｚ：吸着曲線における３０℃相対湿度１００％での水分吸着量（ｍｇ／ｇ）
透過型電子顕微鏡による該トナーの断面観察において、
該磁性体が、該トナー粒子の断面の輪郭から該断面の重心までの距離の１０％以下の領域に、６０面積％以上１００面積％以下存在し、
透過型電子顕微鏡による該トナーの断面観察において、
該トナー粒子の断面の輪郭から該断面の重心方向へ２００ｎｍ以下の領域における、該磁性体が占める面積比率をＡ１としたとき、
該面積比率Ａ１が３８％以上８５％以下であり、
ナノインデンテーション法で求められるトナーのトナー硬さＡ（Ｎ／ｍ）及びトナー硬さＢ（Ｎ／ｍ）が、下記式（３）を満たし、
Ｘ線光電子分光分析により測定される該トナー粒子の表面に存在する炭素元素の存在量（Ｅ１）に対する鉄元素の存在量（Ｅ２）の比（Ｅ２／Ｅ１）が、０．００１００以下であることを特徴とするトナー。
Ｂ／Ａ≧１．２０ （３）
（式（３）中、該トナー硬さＡは、該トナーを荷重印加速度０．８３μＮ／ｓｅｃの条件で測定した荷重－変位曲線において、縦軸を荷重ａ（ｍＮ）とし、横軸を変位量ｂ（μｍ）とした場合の、０．００μｍ以上０．２０μｍ以下の変位領域における、傾きの平均値であり、
該トナー硬さＢは、該トナーを荷重印加速度２．５０μＮ／ｓｅｃの条件で測定した荷重－変位曲線において、縦軸を荷重ａ（ｍＮ）とし、横軸を変位量ｂ（μｍ）とした場合の、０．００μｍ以上０．２０μｍ以下の変位領域における、傾きの平均値である。）
A toner containing toner particles containing a binder resin and a magnetic material,
the binder resin contains a vinyl resin having an ether structure,
The vinyl resin having an ether structure is a vinyl resin crosslinked with a crosslinking agent represented by the following formula (4),

(In formula (4), m+n is an integer of 2 or more, R _{1 and R 4 independently represent H or CH 3 , R 2 and R 3 independently} represent _a straight chain _having 2 _to 12 carbon atoms or represents a hydrocarbon group having a branched chain.)
The magnetic material is a hydrophobized magnetic material treated with a hydrophobizing agent,
The hydrophobizing agent contains an alkyltrialkoxysilane coupling agent represented by the following formula (I),
C _p H _2p+1 -Si-(OC _q H _2q+1 ) ₃ (I)
(In formula (I), p represents an integer of 8 or more and 16 or less, and q represents an integer of 1 or more and 3 or less.)
satisfying the following (1) and (2) in the moisture adsorption/desorption curve obtained by measuring the vapor adsorption amount of the magnetic material,
(1) 1.7≤Z≤6.0
(2) Y−X≧0.10
X: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the adsorption curve
Y: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the desorption curve
Z: Water adsorption amount (mg/g) at 30°C and 100% relative humidity in the adsorption curve
In cross-sectional observation of the toner with a transmission electron microscope,
The magnetic material is present at 60 area % or more and 100 area % or less in a region of 10% or less of the distance from the contour of the cross section of the toner particle to the center of gravity of the cross section,
In cross-sectional observation of the toner with a transmission electron microscope,
When A1 is the area ratio occupied by the magnetic material in the region of 200 nm or less from the contour of the cross section of the toner particle in the direction of the center of gravity of the cross section,
The area ratio A1 is 38% or more and 85% or less,
The toner hardness A (N/m) and the toner hardness B (N/m) of the toner obtained by the nanoindentation method satisfy the following formula (3),
The ratio (E2/E1) of the abundance (E2) of the iron element to the abundance (E1) of the carbon element present on the surface of the toner particles measured by X-ray photoelectron spectroscopy is 0.00100 or less. A toner characterized by:
B/A≧1.20 (3)
(In formula (3), the hardness A of the toner is a load-displacement curve obtained by measuring the toner at a load application speed of 0.83 μN/sec, with the vertical axis representing the load a (mN) and the horizontal axis representing the displacement The average value of the slope in the displacement region of 0.00 μm or more and 0.20 μm or less when the amount is b (μm),
The hardness B of the toner is a load-displacement curve obtained by measuring the toner under the condition of a load application speed of 2.50 μN/sec. is the average value of the slope in the displacement region of 0.00 μm or more and 0.20 μm or less. )

According to the present invention, in the case of outputting an image using rough paper, a toner having good halftone density uniformity in a low-temperature and low-humidity environment, dot reproducibility in a high-temperature and high-humidity environment, and a good density retention rate in long-term use is provided. Obtainable.

Example of load-displacement curve of toner by nanoindentation method

Unless otherwise specified, the descriptions of "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits that are endpoints.
The inventors of the present invention have diligently studied a toner capable of stabilizing the image quality of halftone images in a low-temperature, low-humidity environment and in a high-temperature, high-humidity environment when printing on rough paper.
To this end, the inventors first investigated the cause of the decrease in dot reproducibility of halftone images in a high-temperature, high-humidity environment.
In a high-temperature and high-humidity environment, the amount of absolute water in the air is large, and the amount of charge on the toner tends to decrease due to the influence of the water. Therefore, the force received from the electric field in the developing process and the transfer process becomes smaller, and the electrostatic force that causes the toner to fly tends to become smaller in each process.
In addition, a large amount of water tends to increase the non-electrostatic adhesion force between each member and the toner, which tends to hinder the flying of the toner in each process.

From the above, it was found that the driving force for moving the toner from the developing sleeve onto the photosensitive drum and then onto the paper is low, and the dot reproducibility of the halftone image is degraded due to the effects of each process.
In particular, when rough paper is used, it has been found that unevenness in the electric field strength applied to the toner occurs in the convex and concave portions of the paper during the transfer process, and this tends to appear as uneven dot reproducibility of the halftone image.
In order to improve this, a certain effect can be obtained by increasing the charge amount of the toner by means such as increasing the coverage of the external additive. However, it has been found that simply increasing the charge amount reduces the halftone density uniformity in a low-temperature, low-humidity environment, resulting in a trade-off relationship.

Specifically, in one image, a difference in density tends to occur between a halftone portion placed immediately after a black background portion and a halftone portion placed immediately after a white background portion.
It is considered that the reason why the above density difference occurs is that there is a difference in the charge amount distribution of the toner on the developing sleeve immediately after the black background portion and immediately after the white background portion.
On the developing sleeve immediately after the black background, the toner is consumed and new toner is constantly supplied. Cheap. The charged toner accumulates in the lower layer of the developing sleeve, resulting in a broad charge amount distribution.
Therefore, there is a difference in the charge amount distribution of the toner on the developing sleeve immediately after the black background portion and immediately after the white background portion, resulting in a difference in developability of the halftone portion. Furthermore, it has been found that when rough paper is used, the unevenness of the transfer electric field occurs due to the unevenness of the paper, which amplifies the halftone density unevenness and reduces the density uniformity.

As described above, it has been found that there is a tendency of a trade-off between dot reproducibility in a high-temperature, high-humidity environment and density uniformity in a low-temperature, low-humidity environment.
As a result of intensive studies by the inventors of the present invention, it was found that a magnetic substance having a specific moisture adsorption/desorption property is contained inside the toner particles, and the magnetic substance is present in the vicinity of the toner particle surface in a specific ratio, thereby reducing the temperature. It has been found that the charging characteristics of the toner are improved in a low-humidity environment and a high-temperature and high-humidity environment, and the durability stability is also improved.
As a result, even when an image is output using rough paper, it is found that halftone density uniformity in a low-temperature, low-humidity environment and dot reproducibility and density retention rate in a high-temperature, high-humidity environment are improved. Completed.

That is, the present invention
A toner containing toner particles containing a binder resin and a magnetic material,
satisfying the following (1) and (2) in the moisture adsorption/desorption curve obtained by measuring the vapor adsorption amount of the magnetic material,
(1) 1.5≤Z≤10.0
(2) Y−X≧0.10
X: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the adsorption curve
Y: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the desorption curve
Z: Water adsorption amount (mg/g) at 30°C and 100% relative humidity in the adsorption curve
In cross-sectional observation of the toner with a transmission electron microscope,
The magnetic material is present at 60 area % or more and 100 area % or less in a region of 10% or less of the distance from the contour of the cross section of the toner particle to the center of gravity of the cross section.

The toner particles are characterized by containing a magnetic material having specific moisture adsorption/desorption properties inside, and the magnetic material being present in the vicinity of the toner particle surface in a specific ratio.
A magnetic material having specific moisture adsorption/desorption characteristics exists in the vicinity of the toner particle surface in a specific state, so that both act synergistically, and the charging characteristics of the toner in both low-temperature and low-humidity environments and high-temperature and high-humidity environments are improved. It becomes good, and its durability stability also becomes good.

First, the magnetic material will be explained. Toner particles must contain a binder resin and a magnetic material.
The water adsorption/desorption curve of the magnetic material must satisfy the following formulas (1) and (2).
(1) 1.5≤Z≤10.0
(2) Y−X≧0.10
X: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the adsorption curve
Y: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the desorption curve
Z: Water adsorption amount (mg/g) at 30°C and 100% relative humidity in the adsorption curve

X value of the magnetic material (water adsorption amount at 30 ° C. relative humidity 10% in the adsorption curve), Y value (water adsorption amount at 30 ° C. relative humidity 10% in the desorption curve), Z value (30 ° C. relative humidity 100% can be measured by the method described later.

It is necessary that the water adsorption/desorption curve of the magnetic material satisfies the formula (1).
Z is the water adsorption amount at 30° C. and 100% relative humidity, and Z is an index of the ability of the magnetic material to adsorb water. When Z is 10.0 or less, the amount of moisture adsorbed by the magnetic material present near the surface of the toner particles is not too large in a high-temperature and high-humidity environment. It is possible to suppress the leakage phenomenon in which
Therefore, the charge amount of the toner can be stabilized in a high-temperature and high-humidity environment, and dot reproducibility of a halftone image can be improved even when rough paper is used.
Z is preferably 8.0 or less, more preferably 6.0 or less.
On the other hand, Z is 1.5 or more. As a result, the density uniformity of halftone images is improved when rough paper is used in a low-temperature, low-humidity environment. It is preferably 1.7 or more, more preferably 1.8 or more.

The inventors of the present invention made extensive studies to improve the density uniformity of halftone images, and as a result, found that the essential cause of this problem was uneven charge distribution on the surface of the toner particles.
If the formulas (1) and (2) and the state of existence of a specific magnetic material are satisfied, the magnetic material present in the vicinity of the surface of the toner particles will have an appropriate amount of moisture under a low-temperature, low-humidity environment. It is presumed that this suppresses the unevenness of the charges on the surfaces of the toner particles, and that the effect of uniformizing the charges on the surfaces is exhibited.
A specific description will be given below.

Even if the average charge amount of the toner is the same, if there is an uneven charge on the surface of the toner particles, the portion where the charge is concentrated will locally have a high charge amount, and the mirror force between the toner and the developing sleeve will be reduced. It is easy to increase the adhesive force as the temperature increases.
In a low-temperature and low-humidity environment, the average charge amount of the toner tends to be high, so the uneven charge distribution on the surface of the toner particles is further increased. Therefore, in a state where the toner is not consumed, such as after the white background portion, the phenomenon of entrainment of the toner with respect to the developing sleeve becomes conspicuous.

As a result, a difference occurs in the average charge amount of the toner on the developing sleeve and the distribution of the charge amount after the white background portion and after the black background portion. As a result, unevenness occurs in developability and transferability, and the uniformity of halftone density decreases. In addition, unevenness in transfer electric field strength on rough paper tends to promote unevenness in density.
The inventors of the present invention have found that the above problem can be solved by arranging a magnetic material having an appropriate water-holding ability even in a low-temperature and low-humidity environment in the vicinity of the toner particle surface at a certain ratio.
It is presumed that this is due to the fact that the magnetic material and the water carried by the magnetic material form a pseudo conductive path, uniformize the surface resistance of the toner particles, and uniform the charge density distribution on the surface of the toner particles.

The magnetic material must have Z of 1.5 or more. When Z is 1.5 or more, the magnetic material can easily carry an appropriate amount of water even in a low-temperature and low-humidity environment, and halftone density uniformity in a low-temperature and low-humidity environment increases, which is preferable. Z is preferably 1.8 or more, more preferably 2.0 or more.
Z can be controlled by the particle size of the magnetic material, the type and amount of the hydrophobizing agent used to treat the magnetic material, and the treatment method of the hydrophobizing agent.

Also, the magnetic material must satisfy the formula (2).
(2) Y−X≧0.10
X: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the adsorption curve
Y: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the desorption curve
Here, the process of adsorbing moisture from 0% relative humidity to 100% relative humidity at 30°C is called an adsorption process, and the process of desorbing moisture from a relative temperature of 100% to 0% relative humidity is called a desorption process. to

YX indicates the difference between the amount of moisture adsorbed by the magnetic material during the adsorption process and the amount of moisture adsorbed by the magnetic material that has undergone the desorption process after being adsorbed up to a relative humidity of 100%. It shows that the larger the YX, the more water the magnetic material once adsorbed to the surface can retain even in a low-humidity environment.
When the toner satisfies the formula (2), it becomes possible for the magnetic material to carry an appropriate amount of water even in a low-temperature and low-humidity environment, and even when rough paper is used, halftone image uniformity is improved. preferable.
YX is preferably 0.15 or more, more preferably 0.20 or more. Although the upper limit is not particularly limited, it is preferably 3.00 or less, more preferably 2.00 or less, further preferably 1.00 or less, and even more preferably 0.80 or less. .
YX can be controlled by the particle size of the magnetic material, the type and amount of the hydrophobizing agent used to treat the magnetic material, and the treatment method of the hydrophobizing agent.

Further, in observation of the cross section of the toner with a transmission electron microscope, the magnetic material is present in an area of 60 area % or more and 100 area % or less in a region of 10% or less of the distance from the contour of the toner particle (toner particle surface) to the center of gravity of the cross section. Must exist.
Hereinafter, the above value may be simply referred to as "the magnetic substance abundance ratio in the 10% region". A method of measuring the magnetic substance abundance ratio in the 10% region will be described later.
As described above, by arranging a magnetic material having specific physical properties in the vicinity of the toner particle surface, as a synergistic effect thereof, the charge density distribution on the toner particle surface is made uniform in a low-temperature, low-humidity environment, resulting in halftone density uniformity. becomes good.

In addition, when the magnetic material abundance in the 10% region is 60 area % or more and 100 area % or less, the surface of the toner particles becomes hard due to the filler effect of the magnetic material. Toner cracking can be suppressed. Therefore, the halftone density retention rate is improved in a high-temperature and high-humidity environment, and the toner has excellent durability.

In order to improve the halftone density uniformity in a low-temperature, low-humidity environment and the halftone density retention rate in a high-temperature, high-humidity environment, the magnetic material presence rate in the 10% area is preferably 65 area % or more and 100 area % or less. It is preferably 70 area % or more and 100 area % or less, and further preferably 70 area % or more and 95 area % or less.
The magnetic substance abundance in the 10% region depends on the selection of the suspension polymerization method as the toner manufacturing method, the particle size and content of the magnetic substance, the type and amount of the hydrophobizing agent for treating the magnetic substance, and the hydrophobizing agent. can be controlled by the processing method of

The toner contains toner particles containing magnetic material.
Magnetic substances include magnetic iron oxides such as magnetite, maghemite, and ferrite, and magnetic iron oxides including other metal oxides; metals such as Fe, Co, and Ni, or these metals and Al, Co, and Cu , Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W, V, and mixtures thereof.
Among these, magnetite is preferable, and its shape includes polyhedron, octahedron, hexahedron, sphere, acicular, scaly, and the like. are preferred for increasing the image density.

The number average particle size of the primary particles of the magnetic material is preferably 50 nm or more and 500 nm or less, more preferably 100 nm or more and 300 nm or less, and even more preferably 150 nm or more and 250 nm or less.
The number average particle size of the primary particles of the magnetic material present in the toner particles can be measured using a transmission electron microscope. A measuring method will be described later.

The content of the magnetic material is preferably from 35 parts by mass to 100 parts by mass, more preferably from 45 parts by mass to 95 parts by mass, based on 100 parts by mass of the binder resin. When the content of the magnetic material is within the above range, it becomes easier to control the content of the magnetic material in the above-mentioned 10% region within a preferable range, and the covering characteristics and magnetic characteristics of the toner are improved.
The magnetic substance content in the toner can be measured using a thermal analyzer TGA Q5000IR manufactured by PerkinElmer. The measurement method is to heat the toner from room temperature to 900°C at a rate of temperature increase of 25°C/min in a nitrogen atmosphere, and the weight loss from 100°C to 750°C is the weight of the component excluding the magnetic material from the toner, and the remaining weight. is the amount of magnetic material.

The following can be exemplified as the method for manufacturing the magnetic material.
An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide in an amount equal to or greater than that of the iron component to the ferrous salt aqueous solution. While maintaining the pH of the prepared aqueous solution at pH 7 or higher, air is blown into the aqueous solution, and ferrous hydroxide is oxidized while the aqueous solution is heated to 70° C. or higher to generate seed crystals that will serve as the core of the magnetic material.

Next, an aqueous solution containing 1 equivalent of ferrous sulfate based on the amount of alkali previously added is added to the slurry containing the seed crystals. While maintaining the pH of the liquid at 5 to 10 and blowing in air, the reaction of ferrous hydroxide is promoted to grow magnetic iron oxide particles with the seed crystal as the core. At this time, it is possible to control the shape and magnetic properties of the magnetic material by selecting arbitrary pH, reaction temperature, and stirring conditions. Although the pH of the liquid shifts to the acidic side as the oxidation reaction progresses, it is preferable not to make the pH of the liquid less than 5. A magnetic material can be obtained by filtering, washing, and drying the magnetic iron oxide particles obtained in this manner by conventional methods.

In order to allow the magnetic material to exhibit the above-described moisture adsorption/desorption properties, it is preferable to treat the particle surfaces of the magnetic material with a hydrophobizing agent to increase the hydrophobicity and control the magnetic material to have a certain moisture adsorption property. . For this purpose, although not particularly limited, a magnetic material subjected to surface treatment using a hydrophobizing agent having a relatively large carbon number represented by formula (I) described later and using a treatment apparatus described later is preferred.
This makes it possible to uniformly react the hydrophobizing treatment agent on the surface of the magnetic particles to develop high hydrophobicity. can be sexualized.

The magnetic substance is preferably a hydrophobized magnetic substance represented by the following formula (I), which is hydrophobized using an alkyltrialkoxysilane coupling agent as a hydrophobizing agent. The hydrophobized magnetic material has a magnetic material and a hydrophobizing agent for the surface of the magnetic material.
C _p H _2p+1 -Si-(OC _q H _2q+1 ) ₃ (I)
In formula (I), p is an integer of 6 or more and 20 or less (preferably 8 or more and 16 or less, more preferably 10 or more and 14 or less), q is 1 or more and 3 or less (preferably 1 or 2, more preferably 1 ) indicates an integer.
When p in the above formula is 6 or more, sufficient hydrophobicity can be imparted. can be suppressed, which is preferable.

By treating the surface of the magnetic material with the above-mentioned hydrophobizing agent by a preferable treatment method described later, the hydrophobicity of the magnetic material surface can be easily increased even in a state in which hydroxyl groups are partially left on the magnetic material surface. This allows the YX value to be increased while controlling Z to a specific range.
As a result, density uniformity in a low-temperature, low-humidity environment, dot reproducibility, and density retention rate in a high-temperature, high-humidity environment are improved.
p is preferably an integer of 8 or more and 14 or less, and more preferably an integer of 8 or more and 12 or less. More preferably, q is an integer of 1 or 2.

The amount of the hydrophobizing agent to be added is preferably 0.3 parts by mass or more and 2.0 parts by mass or less with respect to 100 parts by mass of the untreated magnetic material.
When the amount is 0.3 parts by mass or more, the hydrophobicity of the magnetic material is enhanced, and Z can be easily controlled to be small. More preferably, it is 0.5 parts by mass or more.
In addition, when the content is 2.0 parts by mass or less, the presence of an appropriate residual hydroxyl value on the surface of the magnetic particles makes it possible to enhance the water-carrying property of the surface of the magnetic particles and increase the value of YX. It is more preferably 1.5 parts by mass or less, and still more preferably 1.3 parts by mass or less.
When using the above silane coupling agent, it is possible to treat alone or to use a plurality of them for treatment. When using a plurality of them together, they may be treated with each coupling agent individually or simultaneously. Alternatively, a titanium coupling agent or the like may be used in combination.

The method of hydrophobizing treatment is not particularly limited, but the following method is preferred.
The hydrophobizing treatment agent is uniformly reacted on the surface of the magnetic particles to develop a high level of hydrophobicity. It is preferable to carry out the hydrophobizing treatment in a dry process using a kneader or a kneader.
Here, as the wheel type kneader, Mixmuller, Multimul, Stotsmill, counterflow kneader, Eirich mill, etc. can be applied, and Mixmuller is preferably applied.
When a wheel-type kneader or a kneader is used, three actions of compression, shearing and spatula action can be exhibited.

The compressive action presses the hydrophobizing agent present between the particles of the magnetic material against the surface of the magnetic material, thereby enhancing the adhesion and reactivity with the particle surface. A shearing force is applied to each of the hydrophobizing agent and the magnetic material by the shearing action, thereby stretching the hydrophobizing agent and breaking apart the particles of the magnetic material to loosen the aggregates. Further, by the action of the spatula, the hydrophobizing agent existing on the surface of the magnetic particles can be spread uniformly as if stroked with the spatula.
By continuously and repeatedly expressing the above three actions, the surfaces of individual particles are evenly hydrophobized while disaggregating into individual particles, without breaking up and re-aggregating the magnetic particles. be able to.

Generally, the hydrophobizing agent represented by the formula (I) having a relatively large number of carbon atoms tends to be difficult to uniformly treat the surface of the magnetic particles at the molecular level because the molecules are large and bulky. Treatment by the above method is preferable because it enables stable treatment.
Then, when the magnetic material is subjected to the hydrophobic treatment using the hydrophobic treatment agent represented by the formula (I) using a wheel-type kneader or a kneader, the surface of the particles of the magnetic substance reacts with the hydrophobic treatment agent. The remaining hydroxyl values that have not reacted with the moieties can alternately exist to form a coexisting state.
By making the particle surface of the magnetic material in such a state, it is possible to have a certain degree of water adsorption while increasing the hydrophobicity, Z can be set in an appropriate range, and the YX value can be increased. be able to.

The toner particles contain a binder resin.
Examples of the binder resin include the following.
Vinyl resin, styrene resin, styrene copolymer resin, polyester resin, polyol resin, polyvinyl chloride resin, phenolic resin, natural resin-modified phenolic resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate , silicone resins, polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral resins, terpene resins, coumarone-indene resins, petroleum-based resins.
Preferred are vinyl-based resins, styrene-based copolymer resins, polyester resins, mixtures of polyester resins and vinyl-based resins, or hybrid resins obtained by partially reacting both.

The toner particles may contain a release agent.
Examples of release agents include waxes mainly composed of fatty acid esters such as carnauba wax and montan acid ester wax; Methyl ester compounds having a hydroxy group obtained by hydrogenation of vegetable oils; Saturated fatty acid monoesters such as stearyl stearate and behenyl behenate; Dibehenyl sebacate, distearyl dodecanedioate, dioctadecanedioate Diesters of saturated aliphatic dicarboxylic acids such as stearyl and saturated aliphatic alcohols; Diesters of saturated aliphatic diols and saturated fatty acids such as nonanediol dibehenate and dodecanediol distearate, low molecular weight polyethylene, low molecular weight polypropylene , microcrystalline wax, paraffin wax, Fischer-Tropsch wax and other aliphatic hydrocarbon waxes; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax or block copolymers thereof; styrene in aliphatic hydrocarbon waxes Waxes grafted with vinyl monomers such as or acrylic acid; Saturated straight chain fatty acids such as palmitic acid, stearic acid and montanic acid; Unsaturated fatty acids such as brassic acid, eleostearic acid and parinaric acid ; Saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubir alcohol, ceryl alcohol, and melisyl alcohol; Polyhydric alcohols such as sorbitol; Fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide saturated fatty acid bisamides such as methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, and hexamethylenebisstearic acid amide; unsaturated fatty acid amides such as dioleyladipate and N,N'-dioleylsebacamide; aromatic bisamides such as m-xylenebisstearate and N,N'-distearylisophthalamide; Aliphatic metal salts (generally referred to as metal soaps) such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate; long-chain alkyl alcohols or long-chain alkyl carboxylic acids having 12 or more carbon atoms; mentioned.

Among these release agents, monofunctional or bifunctional ester waxes such as saturated fatty acid monoesters and diesters, and hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax are preferred.
Further, the melting point of the release agent, which is defined by the peak temperature of the maximum endothermic peak during temperature rise measured by a differential scanning calorimeter (DSC), is preferably 60°C to 140°C. More preferably, it is 60°C to 90°C. When the melting point is 60° C. or higher, the storage stability of the toner is improved. On the other hand, when the melting point is 140° C. or less, the low-temperature fixability tends to be improved.
The content of the release agent is preferably 3 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the binder resin.

The toner particles may contain charge control agents.
As charge control agents for negative charging, organometallic complex compounds and chelate compounds are effective, and examples thereof include monoazo metal complex compounds, acetylacetone metal complex compounds, and aromatic hydroxycarboxylic acid or aromatic dicarboxylic acid metal complex compounds. be done.
Specific examples of commercially available products include Spilon Black TRH, T-77, T-95 (Hodogaya Chemical Industry Co., Ltd.), BONTRON (registered trademark) S-34, S-44, S-54, E-84, E -88 and E-89 (Orient Chemical Industry Co., Ltd.).
These charge control agents can be used alone or in combination of two or more. The amount of the charge control agent used is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, and preferably 0.1 parts by mass or more with respect to 100 parts by mass of the binder resin, in terms of the amount of charge on the toner. It is more preferably 5.0 parts by mass or less.

A magnetic substance can be used as a colorant for the toner, and a conventionally known colorant can be used in combination. For example, carbon black, grafted carbon, and yellow, magenta, and cyan colorants shown below that are toned to black can be used as the black colorant.
Yellow colorants include compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

Magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds, and the like.
Cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like. These colorants can be used singly or in combination, or in the form of a solid solution.
The content of the coloring agent (other than the magnetic material) is preferably 1 part by mass or more and 20 parts by mass or less, and more preferably 2 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the binder resin. more preferred.

It is preferable that the toner hardness A (N/m) and the toner hardness B (N/m) obtained by the nanoindentation method satisfy the following formula (3).
B/A≧1.10 (3)
(In formula (3), the hardness A of the toner is a load-displacement curve obtained by measuring the toner at a load application speed of 0.83 μN/sec. The average value of the slope in the displacement region of 0.00 μm or more and 0.20 μm or less when the amount is b (μm),
The hardness B of the toner is a load-displacement curve obtained by measuring the toner under the condition of a load application speed of 2.50 μN/sec. is the average value of the slope in the displacement region of 0.00 μm or more and 0.20 μm or less. )

B/A is an index of responsiveness to an external force relating to hardness in the vicinity of the toner particle surface. A larger B/A indicates that the surface hardness of the toner particles is hardened only when subjected to an external force, that is, the surface hardness of the toner particles depends on the frequency of the force.
The above-mentioned characteristics are manifested when the external force applied to the external additive of the toner is transmitted to the magnetic material near the surface of the toner particle, generating a repulsive force, and apparently hardening the surface of the toner particle due to the stress propagation effect. do.

Since the toner exhibits a stress propagation effect, concentration of residual stress in the vicinity of the external additive is alleviated, and fine cracks on the surface of the toner particles can be suppressed.
Further, by propagating the external force to the magnetic material inside the toner particles, the effect of equalizing the electric charge on the toner particle surface due to the water carried by the magnetic material is enhanced.
Therefore, even in a very low temperature environment (7°C, 30% relative humidity), which is a severer environment for toner charge-up than in a normal low-temperature, low-humidity environment (15°C, 10% relative humidity), halftone density uniformity is improved. .
B/A is more preferably 1.20 or more, still more preferably 1.30 or more, and particularly preferably 1.40 or more. Although the upper limit is not particularly limited, it is preferably 6.00 or less, more preferably 5.00 or less, further preferably 3.00 or less, and even more preferably 2.50 or less. .

In order to increase B/A, a portion that is harder than the outermost surface of the toner particle and whose position is fixed (hereinafter sometimes referred to as a tough portion) is arranged inside the toner particle surface. is preferred. Specifically, it is preferable to increase the abundance of the magnetic material in the 10% region, reduce the particle size of the magnetic material, and increase the content of the magnetic material.
Further, since the B/A increases as the stress propagating to the tough portion increases, it is preferable that the toner particles contain a relatively flexible resin. Specifically, it preferably contains a vinyl resin having a preferable ether structure, which will be described later, and preferably has a crosslinked structure derived from a crosslinking agent, which will be described later.

As a result of intensive studies, the inventors have found that the nanoindentation method can be used as a technique for evaluating the stress propagation effect described above. The nanoindentation method is a technique for evaluating the mechanical properties of minute regions.
In this nano-indentation method, the thickness range of the sample to be evaluated was set to 0.20 μm, and two types of measured values were compared with different set maximum loads and load application times to obtain indices for toner evaluation.

FIG. 1 is an example of a load-displacement curve obtained when toner is evaluated by the nanoindentation method. Toner hardness A (hereinafter also simply referred to as “A”, the unit is N/m) is obtained by slowing down the pressing speed of the indenter of the nanoindenter within a range that enables evaluation of the vicinity of the toner particle surface. Therefore, the inventors consider that the hardness of the toner is measured when the stress propagates to a shallower depth and the stress does not propagate to the tough portion. Therefore, A is an index of the hardness of the toner surface when a load is relatively hard to apply.
On the other hand, the toner hardness B (hereinafter also simply referred to as “B” and the unit is N/m) is determined by adjusting the pressing speed of the indenter of the nanoindenter within a range that enables evaluation of the vicinity of the toner particle surface. The inventors believe that increasing the speed increases the depth to which the stress propagates and measures the hardness when the stress propagates to the tough portion.
The B is an index of how easily the external additive is embedded when the external additive receives a force inside the developing device.

The binder resin preferably contains a vinyl resin having an ether structure.
Since the binder resin contains a vinyl resin having an ether structure, the surface and inside of the toner particles tend to behave softly and elastically, and microcracks and internal strain on the toner surface in extremely low-temperature and low-humidity environments are prevented. easy to suppress. Therefore, it is possible to improve dot reproducibility during endurance use in an extremely low temperature and low humidity environment.
The vinyl resin having an ether structure is preferably a resin containing an alkylene glycol having an unsaturated double bond as a constituent.
Also, the vinyl resin having an ether structure is preferably a resin having a crosslinked structure.
A crosslinked structure can be introduced by using a crystalline polyester having a polymerizable unsaturated group, or by using a polyfunctional monomer shown below, which may be used in combination. .

When introducing a crosslinked structure using a polyfunctional monomer, a vinyl-based polyfunctional monomer is preferred.
Examples of vinyl polyfunctional monomers include bifunctional monomers: polyalkylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polytetramethylene glycol dimethacrylate. , 1,6-hexanediol dimethacrylate, neopentylglycol dimethacrylate, divinylbenzene, divinylnaphthalene, acrylic-modified silicone at both ends, and methacrylic-modified silicone at both ends; trifunctional monomers: trimethylolpropane triacrylate, trimethylolpropane trimethacrylate tetrafunctional monomer: at least one polyfunctional monomer selected from the group consisting of tetramethylolmethane tetraacrylate and tetramethylolmethane tetramethacrylate. Among these, bifunctional monomers are preferred.

Among others, the vinyl resin having an ether structure is preferably a vinyl resin crosslinked with a crosslinking agent represented by the following formula (4).
The content of the vinyl resin having an ether structure in the binder resin is preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less.
In addition, the content of the structure derived from the cross-linking agent in the vinyl resin cross-linked with the cross-linking agent is preferably 0.05% by mass or more and 5.0% by mass or less, more preferably 0.09% by mass or more and 3.0% by mass. % by mass or less.

In formula (4), m+n is an integer of 2 or more (preferably an integer of 2 or more and 25 or less), R ₁ and R ₄ independently represent H or CH ₃ , R ₂ and R ₃ independently It represents a straight or branched hydrocarbon group (preferably an alkylene group) having 2 or more and 12 or less (preferably 2 or more and 6 or less) carbon atoms.
The molecular weight of the cross-linking agent is preferably 200 or more and 2000 or less, more preferably 300 or more and 1500 or less, from the viewpoint of cross-linking reactivity and flexibility of the cross-linking structure.
When the binder resin contains a vinyl resin crosslinked with the crosslinking agent represented by the above formula (4), a highly flexible and elastic crosslinked structure can be formed in the vicinity of the surface of the toner particles. The stress propagation effect on
As a result, the dot reproducibility is further improved in the case of long-term use in an extremely low temperature and low humidity environment.

Examples of cross-linking agents that satisfy the above formula (4) are shown below.
polyethylene glycol #200 diacrylate (A200), polyethylene glycol #400 diacrylate (A400), polyethylene glycol #600 diacrylate (A600), polyethylene glycol #1000 diacrylate (A1000);
Dipropylene glycol diacrylate (APG100), tripropylene glycol diacrylate (APG200), polypropylene glycol #400 diacrylate (APG400), polypropylene glycol #700 diacrylate (APG700), polytetrapropylene glycol #650 diacrylate (A-PTMG) -65).
More preferably, the cross-linking agent represented by formula (4) is a cross-linking agent represented by formula (5) below.

In formula (5), p+q is an integer of 2 or more (preferably an integer of 3 or more and 12 or less), and R ₅ and R ₆ independently represent H or CH ₃ .
When the binder resin contains a vinyl resin crosslinked with the crosslinking agent represented by the above formula (5), it is easy to form a flexible crosslinked structure especially in the vicinity of the surface of the toner particles among the crosslinking agents having an ether structure.
It is presumed that this is because the branched structure of the alkylene moiety increases steric hindrance and flexibility of the main chain skeleton.
Further, since the alkylene moiety has a branched structure with respect to the polar ether group, the chargeability of the toner tends to be good without excessively increasing the affinity with water.
Therefore, it is preferable because the dot reproducibility is good even when it is used endurance in an extremely low-temperature and low-humidity environment.
Examples of cross-linking agents that satisfy the above formula (5) are shown below.
Dipropylene glycol diacrylate (APG100), tripropylene glycol diacrylate (APG200), polypropylene glycol #400 diacrylate (APG400), polypropylene glycol #700 diacrylate (APG700).

The toner may have toner particles and an external additive.
Examples of external additives include metal oxide fine particles (inorganic fine particles) such as silica fine particles, alumina fine particles, titania fine particles, zinc oxide fine particles, strontium titanate fine particles, cerium oxide fine particles, and calcium carbonate fine particles. Composite oxide fine particles using two or more kinds of metals can also be used, and two or more kinds selected in arbitrary combination from these fine particle groups can also be used.
In addition, resin fine particles and organic-inorganic composite fine particles of resin fine particles and inorganic fine particles can also be used.
The external additive more preferably contains at least one selected from the group consisting of silica fine particles and organic-inorganic composite fine particles.

Silica fine particles include sol-gel silica fine particles produced by a sol-gel method, aqueous colloidal silica fine particles, alcoholic silica fine particles, fumed silica fine particles obtained by a vapor phase method, fused silica fine particles, and the like.
Examples of the fine resin particles include resin particles such as vinyl resins, polyester resins, and silicone resins.
Organic-inorganic composite fine particles include organic-inorganic composite fine particles composed of resin fine particles and inorganic fine particles.
The organic-inorganic composite fine particles maintain good durability and chargeability as inorganic fine particles, and at the time of fixing, the resin component with a low heat capacity hardly inhibits coalescence of the toner particles, resulting in fixing inhibition. Hateful. Therefore, it is easy to achieve both durability and fixability.

The organic-inorganic composite microparticles are preferably composite microparticles having projections composed of inorganic microparticles embedded in the surface of resin microparticles (preferably vinyl-based resin microparticles) as a resin component. Composite fine particles having a structure in which inorganic fine particles are exposed on the surface of vinyl-based resin particles are more preferred. More preferably, it is a composite fine particle having a structure having projections derived from the inorganic fine particle on the surface of the vinyl resin fine particle.
Inorganic fine particles constituting the organic-inorganic composite fine particles include fine particles such as silica fine particles, alumina fine particles, titania fine particles, zinc oxide fine particles, strontium titanate fine particles, cerium oxide fine particles and calcium carbonate fine particles.
The content of the external additive is preferably 0.1 parts by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

The external additive may be hydrophobized with a hydrophobizing agent.
Examples of hydrophobizing agents include chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, t-butyldimethylchlorosilane, and vinyltrichlorosilane;
Tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane silane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, i-butyltri ethoxysilane, decyltriethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane Alkoxysilanes such as silane;
Hexamethyldisilazane, hexaethyldisilazane, hexapropyldisilazane, hexabutyldisilazane, hexapentyldisilazane, hexahexyldisilazane, hexacyclohexyldisilazane, hexaphenyldisilazane, divinyltetramethyldisilazane, dimethyltetravinyl silazanes such as disilazane;
Dimethyl silicone oil, methyl hydrogen silicone oil, methylphenyl silicone oil, alkyl-modified silicone oil, chloroalkyl-modified silicone oil, chlorophenyl-modified silicone oil, fatty acid-modified silicone oil, polyether-modified silicone oil, alkoxy-modified silicone oil, carbinol-modified Silicone oils such as silicone oils, amino-modified silicone oils, fluorine-modified silicone oils, and terminally reactive silicone oils;
siloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane, octamethyltrisiloxane;
Fatty acids and metal salts thereof include undecylic acid, lauric acid, tridecylic acid, dodecylic acid, myristic acid, palmitic acid, pentadecylic acid, stearic acid, heptadecylic acid, arachidic acid, montanic acid, oleic acid, linoleic acid, arachidonic acid, and the like. Examples include long-chain fatty acids and salts of said fatty acids with metals such as zinc, iron, magnesium, aluminum, calcium, sodium and lithium.

Among these, alkoxysilanes, silazanes, and silicone oils are preferably used because they are easily hydrophobized. One of these hydrophobizing agents may be used alone, or two or more thereof may be used in combination.
The toner may contain a plurality of external additives in order to improve fluidity and chargeability of the toner.

Further, the ratio (E2/E1) of the abundance (E2) of the iron element to the abundance (E1) of the carbon element present on the surface of the toner particles measured by X-ray photoelectron spectroscopy is 0.00100 or less. is preferred. More preferably, it is 0.000500 or less. Although the lower limit is not particularly limited, it is preferably 0.0000000100 or more, more preferably 0.00000500 or more, and still more preferably 0.0000100 or more.
E2/E1 indicates the degree of exposure of the magnetic material on the surface of the toner particles. When E2/E1 is 0.00100 or less, it can be judged that there is no exposure in general, and dot reproducibility is good even when left for a long time in a high-temperature and high-humidity environment.
E2/E1 is determined by adopting the suspension polymerization method, which is preferable in the present invention, as the method for producing the toner, setting the number of carbon atoms (the value of P) in the alkyltrialkoxysilane coupling agent within a preferable range, and controlling the magnetic material. It can be controlled by controlling the state of the surface treatment to set the Z value and YX value within a preferable range, by controlling the content of the magnetic material, and the like.

In observation of the cross section of the toner with a transmission electron microscope TEM, the area ratio A1 is 38% or more and 85%, where A1 is the area ratio occupied by the magnetic material in the region of 200 nm or less from the contour of the cross section of the toner particle in the direction of the center of gravity of the cross section. % or less.
When the A1 value is 38% or more, the halftone density retention rate is good even after being left for a long time in a high-temperature and high-humidity environment. On the other hand, when it is 85% or less, the chargeability becomes good. More preferably, it is 40% or more and 85% or less.
The area ratio A1 is determined by adopting a suspension polymerization method as a toner manufacturing method, setting the carbon number (value of P) of the alkyltrialkoxysilane coupling agent within a preferable range, and controlling the surface treatment state of the magnetic material. It can be controlled by setting the Z value and the YX value within a preferable range, controlling the content of the magnetic material, and the like.

The existence state of the magnetic material inside the toner particles is observed by using a TEM after processing the toner into pieces. In the cross-sectional image of the toner obtained by TEM observation, the area of 200 nm or less from the contour of the cross-section of the toner particle in the direction of the center of gravity of the cross-section is a range obtained as follows.
That is, the length per unit pixel is calculated from the magnifying power and resolution of the TEM, and based on this, the number of pixels corresponding to 200 nm is calculated. Next, from the contour of the cross section of the toner particles, a boundary line is drawn at a distance of the number of pixels corresponding to 200 nm in the direction of the center of gravity of the cross section. The area from this boundary line to the surface of the toner particles is defined as an area of 200 nm or less in the direction of the center of gravity of the cross section from the outline of the cross section of the toner particles (hereinafter also referred to as area A).

The method for producing the toner will be exemplified below.
From the viewpoint of controlling the state of existence of the magnetic material, it is preferable to produce toner particles in an aqueous medium by a dispersion polymerization method, an association aggregation method, a dissolution suspension method, a suspension polymerization method, an emulsion aggregation method, or the like.
Suspension polymerization is preferable because it facilitates the presence of a magnetic material in the vicinity of the surface of the toner particles.

In the suspension polymerization method, for example, a polymerizable monomer capable of forming a binder resin, a magnetic substance, and, if necessary, a coloring agent, a polymerization initiator, a cross-linking agent, a charge control agent and other additives are added. , to obtain a polymerizable monomer composition. Thereafter, the resulting polymerizable monomer composition is dispersed and granulated in a continuous layer (e.g., aqueous phase) containing a dispersion stabilizer using a suitable stirrer, and polymerized using a polymerization initiator. A reaction is carried out to obtain toner particles having the desired particle size.

Examples of polymerizable monomers include the following.
Styrenic monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene and p-ethylstyrene.
methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, acrylic acid esters such as phenyl acrylate;
Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacrylic acid methacrylic acid esters such as dimethylaminoethyl and diethylaminoethyl methacrylate;
Other monomers such as acrylonitrile, methacrylonitrile and acrylamide are included. These monomers can be used alone or in combination.
Among the monomers described above, the use of styrene-based monomers alone or in combination with other monomers such as acrylic acid esters and methacrylic acid esters controls the toner structure and improves toner development. It is preferable from the point that it is easy to improve a characteristic and durability. In particular, it is more preferable to use styrene and acrylic acid ester or styrene and methacrylic acid ester as main components. That is, it is preferable that the binder resin contains 50% by mass or more of the styrene-acrylic resin.
When a vinyl resin having an ether structure is used, a polymer of at least one selected from the group consisting of acrylic acid esters and methacrylic acid esters, styrene, and a cross-linking agent represented by the above formula (4) is preferred.

As the polymerization initiator used in the production of toner particles by a polymerization method, one having a half-life of 0.5 hours or more and 30 hours or less during the polymerization reaction is preferable. Moreover, it is preferable to use it in the addition amount of 0.5-20 mass parts with respect to 100 mass parts of polymerizable monomers. Then, a polymer having a maximum molecular weight between 5,000 and 50,000 can be obtained, and the toner can be provided with preferable strength and suitable melting properties.

Specific polymerization initiators include 2,2′-azobis-(2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis(cyclohexane-1-carbohydrate nitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo or diazo polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy Carbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxypivalate, di(2-ethylhexyl) peroxydicarbonate , and di(secondary butyl)peroxydicarbonate.
Among these, t-butyl peroxypivalate is preferred.

When the toner is produced by a polymerization method, a cross-linking agent may be added.
The amount added is preferably 0.05 parts by mass or more and 15.0 parts by mass or less, and is preferably 0.10 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. It is more preferably 0.20 to 5.0 parts by mass, even more preferably 0.10 to 3.00 parts by mass, and 0.20 to 3.00 parts by mass. 50 parts by mass or less is particularly preferable.
The cross-linking agent is preferably a cross-linking agent having the above-mentioned ether structure from the viewpoint of easily obtaining the stress propagation effect, and does not contain a highly rigid structure such as an aromatic hydrocarbon group such as a phenylene group. is preferably

The polymerizable monomer composition may contain a polar resin.
Examples of polar resins include homopolymers of styrene and substituted products thereof such as polystyrene and polyvinyltoluene; styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-acrylic acid; Methyl copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer Polymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer Styrenic copolymers such as coalescence, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; methyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, styrene-polyester copolymer, polyacrylate-polyester copolymer, polymethacrylate-polyester copolymer, polyamide resin, Epoxy resins, polyacrylic acid resins, terpene resins, phenolic resins, and the like.
These can be used alone or in combination of two or more. Functional groups such as amino groups, carboxyl groups, hydroxyl groups, sulfonic acid groups, glycidyl groups and nitrile groups may be introduced into these polymers. Among these resins, polyester resins are preferred.

As the polyester resin, a saturated polyester resin, an unsaturated polyester resin, or both of them can be appropriately selected and used.
Usual polyester resins composed of an alcohol component and an acid component can be used, and both components are exemplified below.
Dihydric alcohol components include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, or a bisphenol derivative represented by formula (A) a hydrogenated compound of the compound represented by the following formula (A), a diol represented by the following formula (B), or a diol of a hydrogenated compound of the formula (B).

式（Ａ）中、Ｒはエチレン基又はプロピレン基であり、ｘ及びｙはそれぞれ１以上の整数であり、ｘ＋ｙの平均値は２～１０である。

In formula (A), R is an ethylene group or a propylene group, x and y are each integers of 1 or more, and the average value of x+y is 2-10.

As the dihydric alcohol component, the alkylene oxide adduct of bisphenol A is particularly preferable because it is excellent in chargeability and environmental stability and well-balanced in other electrophotographic properties.
In the case of this compound, the average number of added moles of alkylene oxide is preferably 2 or more and 10 or less from the viewpoint of fixability and toner durability.

Examples of divalent acid components include benzenedicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid and phthalic anhydride, or their anhydrides; anhydride; succinic acid or anhydride thereof substituted with alkyl or alkenyl group having 6 to 18 carbon atoms; unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid, itaconic acid, or anhydride thereof; .

Examples of trihydric or higher alcohol components include glycerin, pentaerythritol, sorbit, sorbitan, and oxyalkylene ethers of novolac phenolic resins. Examples of trihydric or higher acid components include trimellitic acid and pyromellitic acid. Examples include acids, 1,2,3,4-butanetetracarboxylic acid, benzophenonetetracarboxylic acid and anhydrides thereof.
The polyester resin preferably contains 45 mol % or more and 55 mol % or less of the alcohol component when the total of the alcohol component and the acid component is 100 mol %.

The polyester resin can be produced using any catalyst such as a tin-based catalyst, an antimony-based catalyst, or a titanium-based catalyst, but it is preferable to use a titanium-based catalyst.
Further, the polar resin preferably has a number average molecular weight of 2,500 or more and 25,000 or less from the viewpoint of developability, blocking resistance, and durability.
The acid value of the polar resin is preferably 1.0 mgKOH/g or more and 15.0 mgKOH/g or less, more preferably 2.0 mgKOH/g or more and 10.0 mgKOH/g or less.
The content of the polar resin is preferably 2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

The aqueous medium in which the polymerizable monomer composition is dispersed may contain a dispersion stabilizer.
As the dispersion stabilizer, known surfactants, organic dispersants and inorganic dispersants can be used.
Among them, the inorganic dispersant is preferably used because it obtains dispersion stability due to its steric hindrance, so that the stability does not easily deteriorate even when the reaction temperature is changed, it is easy to clean, and it does not adversely affect the toner.
Specific examples of inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, polyvalent metal phosphates such as hydroxyapatite, carbonates such as calcium carbonate and magnesium carbonate, and calcium metasilicate. , calcium sulfate and barium sulfate, and inorganic compounds such as calcium hydroxide, magnesium hydroxide and aluminum hydroxide.

The amount of the inorganic dispersant to be added is preferably 0.2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. Moreover, a dispersion stabilizer may be used independently and may use multiple types together. Furthermore, 0.001 parts by mass or more and 0.1 parts by mass or less of a surfactant may be used together.
When an inorganic dispersant is used, it may be used as it is, but in order to obtain finer particles, fine particles of the inorganic dispersant may be generated in an aqueous medium before use.
For example, in the case of tricalcium phosphate, an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride can be mixed under high-speed stirring to generate fine particles of water-insoluble calcium phosphate, enabling more uniform and finer dispersion. .
Surfactants include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

In the step of polymerizing the polymerizable monomer, the polymerization temperature is usually 40°C or higher, preferably 50°C or higher and 90°C or lower. When the polymerization is carried out in this temperature range, for example, the mold release agent added as necessary precipitates due to phase separation, and encapsulation becomes more complete.
After that, there is a cooling step of cooling from a reaction temperature of about 50° C. or higher to 90° C. or lower to complete the polymerization reaction step. At that time, it is preferable to cool gradually so as to maintain the compatible state of the release agent and the binder resin.
After the polymerization of the polymerizable monomer is completed, the obtained polymer particles are filtered, washed and dried by a known method to obtain toner particles. The toner particles may be used as toner as they are. The toner may be obtained by mixing the toner particles with an external additive and adhering the external additive to the surface of the toner particles. It is also possible to include a classifying step in the production process to remove coarse powder and fine powder contained in the toner particles.

Methods for measuring various physical properties of the toner will be described below.
<Measurement of moisture adsorption/desorption characteristics of magnetic material>
The moisture adsorption/desorption properties of the magnetic material were measured using a "high-precision vapor adsorption measuring device BELSORP-aqua3" (BEL Japan Co., Ltd.). "High-precision vapor adsorption amount measuring device BELSORP-aqua3" reaches solid-gas equilibrium under the condition that only the target gas (water in the case of the present invention) exists, and the solid mass and vapor pressure at this time are calculated. Measure.
First, about 1 g of a sample is introduced into a sample cell and degassed at room temperature and 100 Pa or less for 24 hours. After the degassing is completed, the sample mass is accurately weighed, set in the main body of the device, and measured under the following conditions.
・Air constant temperature bath temperature: 80.0°C
・Adsorption temperature: 30.0°C
・ Adsorbate name: H ₂ O
・Equilibration time: 500 sec
・Temperature waiting: 60min
・ Saturated vapor pressure: 4.245 kPa
・Sample tube exhaust speed: Normal ・Introduction pressure Initial introduction amount: 0.20 cm ³ (STP)・g ⁻¹
・Measured relative pressure P/P0 (adsorption process → desorption process measured): 0.05, 0.10, 0.15
, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, 0.90, 0.95, 1.00
Measure under the above conditions, draw a moisture adsorption/desorption curve at a temperature of 30 ° C., and take the moisture adsorption amount (mg / g) at a humidity of 100% RH (measurement relative pressure is 1.00) in the adsorption process (adsorption curve) as the Z value. ,calculate.
The water adsorption amount in the adsorption process (adsorption curve) at a humidity of 10% RH (measured relative pressure is 0.10) is defined as the X value (mg/g). Then, in the desorption process (desorption curve) after receiving a humidity history up to a humidity of 100% RH (measured relative pressure is 1.00), the water adsorption amount at a humidity of 10% RH (measured relative pressure is 0.10) Y value (mg/g) and YX value, which is the difference between them, is calculated.

(Separation of magnetic material from toner)
The water adsorption/desorption measurement can also be performed using a magnetic substance separated from the toner by the following method.
First, 1 g of toner is added to a 50 mL vial.
Then 20 g of tetrahydrofuran (THF) is added and thoroughly stirred. After that, a neodymium magnet is applied to the bottom of the vial from the outside to hold the magnetic substance, and the THF solution in the vial is discarded.
The operation of adding THF, stirring, and discarding the THF solution is repeated 100 times to isolate the magnetic substance, followed by vacuum drying at 40° C. for 48 hours to isolate the magnetic substance.

<Method for measuring number average particle diameter of primary particles of magnetic material>
The number average particle diameter of the primary particles of the magnetic material is measured using a scanning electron microscope "S-4800" (trade name; manufactured by Hitachi, Ltd.). After sufficiently dispersing the toner to be observed in the epoxy resin, it is cured in an atmosphere at a temperature of 40° C. for 2 days to obtain a cured product. Using a microtome as a flaky sample of the obtained cured product, an image was taken with an S-4800 at a magnification of 10,000 to 40,000 times, and the projected area of 100 primary particles of the magnetic material in the image was measured. do. The equivalent diameter of a circle equal to the projected area is taken as the particle size of the primary particles of the magnetic material, and the average value of the 100 particles is taken as the number average particle size of the primary particles of the magnetic material.
The observation magnification is appropriately adjusted according to the size of the magnetic material. In addition, when the magnetic material can be obtained independently, it is preferable to measure the magnetic material alone by the above method.

<Method for measuring magnetic material abundance in 10% region>
A method of measuring the degree of uneven distribution of the surface of the magnetic material in the cross section of the toner observed with a transmission electron microscope (TEM) is as follows.
First, the toner to be observed is sufficiently dispersed in a room temperature curable epoxy resin.
After that, the cured product obtained by curing in an atmosphere at a temperature of 40° C. for 2 days is observed as a flaky sample with a microtome equipped with a diamond blade as it is or after being frozen. For the cross section of the toner particles to be observed, the circle equivalent diameter (projected area circle equivalent diameter) is obtained from the projected area of the cross section in the TEM image, and the value is ±10% of the number average particle diameter (D1) (μm) of the toner. shall be included in the width of
In the present invention, a transmission electron microscope (Hitachi H-600 model) is used as an apparatus, observation is performed at an acceleration voltage of 100 kV, and measurement is performed using a micrograph with a magnification of 10,000.
The observed image is subjected to binarization using image processing software "ImageJ" (available from https://imagej.nih.gov/ij/) as follows.
The image observed at this time is binarized by selecting "Image-Adjust-Threshold" and setting a threshold so that the entire cross section of the toner particles is extracted in the displayed dialog box. The same image is binarized in the same procedure by changing only the threshold so that only the magnetic material is extracted.
In the binarized image, a line is drawn from the center of gravity of the toner particle cross section to a point on the contour of the toner particle cross section (toner particle surface). 1 of the distance from the contour to the centroid on the line
Locate the 0% position. Then, this operation is performed for one round of the contour of the cross section of the toner particle, and an area of 10% or less of the distance from the contour of the toner particle to the center of gravity of the cross section is specified.
Then, the ratio of the area of the magnetic material existing in the region of 10% or less of the distance from the contour of the toner particle to the center of gravity of the cross section to the total area of the magnetic material existing in the cross section of the toner particle is calculated. 100 toner particles are observed and the arithmetic mean value is adopted.

<Method of Observing Cross Section of Ruthenium Stained Toner with Transmission Electron Microscope (TEM)>
Cross-sectional observation of the toner with a transmission electron microscope (TEM) can be carried out as follows. A cross section of the toner is observed by ruthenium staining. Since the crystalline resin contained in the toner is dyed with ruthenium rather than the amorphous resin such as the binder resin, the contrast becomes clear and the observation is facilitated. Since the amount of ruthenium atoms varies depending on the intensity of staining, the strongly stained portion contains many of these atoms, and the electron beam does not penetrate, making it appear black on the observed image. Electron beams are easily transmitted through it, and the observed image is white.
First, a cover glass (Matsunami Glass Co., square cover glass square No. 1) was coated with toner in a single layer. (5 nm) and a naphthalene film (20 nm) are applied. Next, a PTFE tube (inner diameter Φ 1.5 mm × outer diameter Φ 3 mm × 3 mm) is filled with photo-curing resin D800 (JEOL Ltd.), and the cover glass is placed on the tube. Place them gently so that they touch each other. After the resin is cured by irradiating light in this state, the cover glass and the tube are removed to form a columnar resin in which the toner is embedded on the outermost surface.
Using an ultrasonic ultramicrotome (Leica, UC7) at a cutting speed of 0.6 mm/s, the radius of the toner from the outermost surface of the cylindrical resin (4.0 μm when the weight average particle diameter (D4) is 8.0 μm) ) to expose the cross section of the toner. Next, it is cut so as to have a film thickness of 250 nm, and a thin piece sample of the cross section of the toner is produced. A cross section of the central portion of the toner can be obtained by cutting by such a method.
The thin section sample thus obtained was dyed in a RuO ₄ gas atmosphere of 500 Pa for 15 minutes using a vacuum electron staining apparatus (VSC4R1H, Filgen), and then observed using a TEM (JEM2800, JEOL).
An image is acquired with a TEM probe size of 1 nm and an image size of 1024×1024 pixels. Also, the contrast of the Detector Control panel of the bright-field image is adjusted to 1425, the Brightness to 3750, the Contrast of the Image Control panel to 0.0, the Brightness to 0.5, and the Gammma to 1.00.

<Measurement of area ratio A1>
Using a ruthenium-stained TEM image, A1 is measured as follows.
First, the obtained TEM image is binarized using image processing software "ImageJ" (available from https://imagej.nih.gov/ij/). After that, the equivalent circle diameter (projected area equivalent circle diameter) is obtained from the binarized image of the cross section, and the cross section whose value is within ±5% of the number average particle diameter (D1) (μm) of the toner is selected. .
From the TEM image of the relevant particles, using "ImageJ", areas other than those necessary for measurement are masked, and the area of the unmasked area inside the toner contour and the magnetic material existing in the unmasked area Calculate the total area. This method will be specifically described using A1 as an example.
First, the obtained TEM image of the contour of the cross section of the toner particles (hereinafter referred to as image 1) is binarized (hereinafter referred to as image 2) so that the contour and inside are white, and the other portion corresponding to the background is black. description)
Next, in order to calculate the magnification of the mask, in image 1, the length per unit pixel number is calculated. Next, from the calculated value, the number of pixels corresponding to 200 nm, which is the distance from the contour of the toner particle to the boundary line of the area A, is calculated (hereinafter referred to as x1).
Similarly, the number of pixels corresponding to the toner particle size measured using the above method is calculated (hereinafter referred to as x2). Then, the magnification M of the mask is calculated from (x1-x2)/x1.
Next, image 2 is reduced to the calculated magnification M (the reduced image is referred to as image 3). At this time, unlike the image 2, the outline and inside of the toner particles are set to be black, and the other portions corresponding to the background are set to be white (transparent).
Next, image 2 and image 3 are added together. At this time, the image 2 and the image 3 are added using the “Image Calculator” function of “ImageJ”, and the area from the contour of the toner particle cross section to the center of gravity of the toner particle cross section up to 200 nm is white, and the other parts are white. is black, creating image 4. The area S1 of the white region in this image 4 is measured.
Next, the created image 4 and the TEM image described above are similarly added using the "Image Calculator" to create an image 5 in which the region other than the measurement site is masked. This image 5 is binarized, and the magnetic material area S2 inside the mask is measured.
Finally, the area ratio A1 occupied by the magnetic material in the region A is calculated by S2/S1×100. The cross section of 100 toner particles is observed and the arithmetic mean value is adopted.

<Measurement of E2/E1 values by X-ray photoelectron spectroscopy (ESCA)>
The ratio (E2/E1) of the abundance of iron element (E2) to the abundance of carbon element (E1) present on the surface of the toner particles measured by X-ray photoelectron spectroscopy (ESCA) is measured by the following method. .
The toner particles are measured after removing external additives and the like adhering to the surfaces of the toner particles from the toner.
1 g of toner is suspended in 20 mL of methanol and subjected to ultrasonic treatment for 30 minutes using an ultrasonic disperser SC-103 (manufactured by SMT Co., Ltd.) to detach the external additive from the toner particles and left to stand for 24 hours.
The sedimented toner particles and the external additive dispersed in the supernatant liquid are separated, recovered, dried at 40° C. for 48 hours to isolate the toner particles, and then the ESCA is measured.

The ESCA apparatus and measurement conditions are as follows.
Apparatus used: Model 1600S X-ray photoelectron spectrometer manufactured by PHI Measurement conditions: X-ray source MgKα (400 W)
Spectral area 800μmφ
From the measured peak intensity of each element, the surface atomic concentration is calculated using the relative sensitivity factor provided by PHI. The peak top range of each element is as follows.
C: 283-293 eV
Fe: 706-730 eV
From the peak top range of each element, the height E1 value corresponding to the peak range of 283 to 293 eV derived from the carbon element present on the surface of the magnetic toner particles and the height E1 value corresponding to the peak range derived from the iron element corresponding to 706 to 730 eV E2 value is obtained, and the ratio E2/E1 is obtained.

<Method for Measuring Toner Hardness by Nanoindentation Method>
Toner hardness is measured by the nanoindentation method using Picodenter HM500 manufactured by Fischer Instrument Co., Ltd. The software uses the attached WIN-HCU. A Vickers indenter (angle: 130°) is used as the indenter.
The measurement consists of a step of pushing the indenter into a predetermined load for a predetermined period of time (hereinafter referred to as a "pressing step"). In this measurement, the load application speed is changed by changing the set time and load.
First, the microscope is focused on a video camera screen connected to the microscope displayed on the software. Note that the object to be focused is the glass plate (
Hardness; 3600 N/mm ² ) is used. At this time, the objective lens is sequentially focused from 5 times to 20 times and then to 50 times. After that, adjustments are made with a 50x objective lens.
Next, using the glass plate that has been focused as described above, the "approach parameter setting" operation is performed to align the Z axis of the indenter. After that, the glass plate is replaced with an acrylic plate, and the “indenter cleaning” operation is performed. "Cleaning the indenter" operation cleans the tip of the indenter with a cotton swab moistened with ethanol, and at the same time aligns the indenter position specified on the software with the indenter position on the hardware. It's about manipulation.

After that, the microscope is focused on the toner to be measured by changing to the toner-coated glass slide. The method of adhering the toner to the slide glass is as follows.
First, the toner to be measured is adhered to the tip of a cotton swab, and excess toner is sieved off with the edge of a bottle or the like. Thereafter, while pressing the shaft of the cotton swab against the edge of the slide glass, the toner adhering to the cotton swab is knocked off so that the toner becomes one layer on the slide glass.
After that, the slide glass with one layer of toner adhered as described above is set on the microscope, the toner is focused with a 50x objective lens, and the tip of the indenter is set on the software so that it is at the center of the toner particle. . The selected toner is limited to particles having a weight-average particle diameter D4 (μm)±1.0 μm in both major and minor diameters.

Measurement is performed by performing the indentation process under the following conditions.
(Pushing process 1)
・Maximum indentation load = 0.25mN
- Pressing time = 300 seconds Under the above conditions, a load application speed of 0.83 µN/sec can be set.
(Pushing process 2)
・Maximum indentation load = 0.50 mN
- Pressing time = 200 seconds Under the above conditions, a load application speed of 2.50 µN/sec can be set.
Data in the displacement region of 0.00 μm or more and 0.20 μm or less from the load-displacement curve obtained when the vertical axis is the load a (mN) and the horizontal axis is the displacement amount b (μm) in these two pushing processes Toner hardnesses A and B are obtained by linearly approximating by the method of least squares. The initial value of displacement (0.00 μm) is defined as the value of displacement at which the positive load is first measured. In addition, 100 points or more of data in the section of 0.00 μm or more and 0.20 μm or less are collected.
The above measurement is performed for 30 toner particles, and an arithmetic mean value is adopted.
In the measurement, the above-described "indenter cleaning" operation (including XY axis alignment of the indenter) is always performed for each particle measurement.

<Method for Measuring Particle Size of Toner (Particles)>
A precision particle size distribution analyzer (trade name: Coulter Counter Multisizer 3) using a pore electrical resistance method and dedicated software (trade name: Beckman Coulter Multisizer 3 Version 3.51, manufactured by Beckman Coulter) are used.
An aperture diameter of 100 μm is used, measurement is performed with 25,000 effective measurement channels, and the measurement data is analyzed and calculated.
The electrolytic aqueous solution used for the measurement can be prepared by dissolving special-grade sodium chloride in ion-exchanged water to a concentration of about 1% by mass, such as Beckman Coulter's ISOTON II (trade name). Before performing measurement and analysis, the dedicated software is set as follows.
In the "change standard measurement method (SOM) screen" of the dedicated software, set the total number of counts in control mode to 50000 particles, set the number of measurements to 1, and set the Kd value to (standard particles 10
. 0 μm, manufactured by Beckman Coulter) is set. By pressing the threshold/noise level measurement button, the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II (trade name), and check the flash of aperture tube after measurement.
In the "pulse-to-particle size conversion setting screen" of the dedicated software, 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 or more and 60 μm or less.

A specific measuring method is as follows.
(1) About 200 mL of the electrolytic aqueous solution is placed in a 250 mL glass round-bottomed beaker exclusively for Multisizer 3, set on a sample stand, and stirred counterclockwise at 24 rpm with a stirrer rod. Then, the dedicated software "Flush Aperture Tube" function is used to remove dirt and air bubbles inside the aperture tube.
(2) About 30 mL of the electrolytic aqueous solution is placed in a 100 mL flat-bottom glass beaker. Here, about 0.5% of a diluted solution obtained by diluting Contaminon N (trade name) (a 10% by mass aqueous solution of a neutral detergent for cleaning precision measuring instruments, manufactured by Wako Pure Chemical Industries, Ltd.) with ion-exchanged water to 3 times its mass is added. Add 3 mL.
(3) An ultrasonic disperser (trade name: Ultrasonic Dispersion System Tetora 150, manufactured by Nikkaki Bios Co., Ltd.) having an electric output of 120 W and containing two oscillators with an oscillation frequency of 50 kHz with a phase shift of 180 degrees. A predetermined amount of ion-exchanged water and about 2 mL of Contaminon N (trade name) are added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the electrolytic aqueous solution in the beaker is maximized.
(5) About 10 mg of toner (particles) is added little by little to the aqueous electrolytic solution in the beaker of (4) while the aqueous electrolytic solution is being irradiated with ultrasonic waves, and dispersed. Then, the ultrasonic dispersion treatment is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water in the water tank is appropriately adjusted to 10°C or higher and 40°C or lower.
(6) The electrolytic aqueous solution of (5), in which toner (particles) are dispersed, is dripped into the round-bottomed beaker of (1) set in the sample stand using a pipette so that the measured concentration is about 5%. adjust to The measurement is continued until the number of measured particles reaches 50,000.
(7) Analyze the measurement data with the dedicated software attached to the apparatus, and calculate the weight average particle size (D4) or number average particle size (D1). The weight average particle diameter (D4) is the "average diameter" on the analysis/volume statistics (arithmetic mean) screen when graph/vol% is set using dedicated software. The number average particle size (D1) is the "average diameter" on the "analysis/number statistical value (arithmetic mean)" screen when graph/number % is set on the dedicated software.

<Measurement method of weight average molecular weight (Mw) and peak molecular weight (Mp) of resin etc.>
The weight average molecular weight (Mw) and peak molecular weight (Mp) of resins and other materials are measured using gel permeation chromatography (GPC) as follows.
(1) Preparation of measurement sample A sample and tetrahydrofuran (THF) are mixed at a concentration of 5.0 mg/mL, left at room temperature for 5 to 6 hours, and then shaken sufficiently to combine THF and the sample. Mix well until there are no lumps. Furthermore, it is allowed to stand at room temperature for 12 hours or longer. At this time, the time from the start of mixing the sample and THF to the end of standing is set to 72 hours or more to obtain a tetrahydrofuran (THF) soluble portion of the sample.
Then, it is filtered through a solvent-resistant membrane filter (pore size: 0.45 to 0.50 μm, Myshoridisc H-25-2 [manufactured by Tosoh Corporation]) to obtain a sample solution.
(2) Measurement of sample Using the obtained sample solution, measure under the following conditions.
Apparatus: High-speed GPC apparatus LC-GPC 150C (manufactured by Waters)
Column: Shodex GPC KF-801, 802, 803, 804, 805, 80
6, 807 (manufactured by Showa Denko) 7-series mobile phase: THF
Flow rate: 1.0 mL/min
Column temperature: 40°C
Sample injection volume: 100 μL
Detector: RI (refractive index) detector In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number.
As a standard polystyrene sample for preparing a calibration curve, Pressure Chemical Co. or Toyo Soda Kogyo Co., Ltd., molecular weights of 6.0×10 ² , 2.1×10 ³ , 4.0×10 ³ , 1.75×10 ⁴ , 5.1×10 ⁴ , 1.1× 10 ⁵ , 3.9×10 ⁵ , 8.6×10 ⁵ , 2.0×10 ⁶ and 4.48×10 ⁶ are used.

<Method for measuring glass transition temperature (Tg)>
The glass transition temperature (Tg) of toner and the like is measured according to ASTM D3418-82 using a differential scanning calorimeter "Q2000" (manufactured by TA Instruments).
Accurately weigh 2 mg of the measurement sample, put it in an aluminum pan, and use an empty aluminum pan as a reference.
The measurement temperature range is set to 30° C. or higher and 200° C. or lower, and once the temperature is raised from 30° C. to 200° C. at a temperature increase rate of 10° C./min, the temperature is lowered from 200° C. to 30° C. at a temperature decrease rate of 10° C./min, and again. , the temperature is raised to 200° C. at a temperature elevation rate of 10° C./min.
In the DSC curve obtained in the second heating process, the intersection of the line between the midpoints of the baselines before and after the specific heat change occurs and the differential thermal curve is taken as the glass transition temperature (Tg).

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these. "Parts" used in Examples and Comparative Examples are based on mass unless otherwise specified.

<Manufacturing Example of Magnetic Body 1>
A ferrous sulfate aqueous solution is mixed with 1.0 equivalent of a caustic soda solution (containing 1% by mass of sodium hexametaphosphate in terms of P relative to Fe) with respect to iron ions, and an aqueous solution containing ferrous hydroxide is prepared. prepared. While maintaining the pH of the aqueous solution at 9, air was blown into the aqueous solution and an oxidation reaction was carried out at 80° C. to prepare a slurry solution for generating seed crystals.
Then, an aqueous solution of ferrous sulfate was added to the slurry so that the amount of alkali (sodium component of caustic soda) was 1.0 equivalent. The pH of the slurry liquid is maintained at 8, and the oxidation reaction proceeds while air is blown in. At the end of the oxidation reaction, the pH is adjusted to 6, washed with water, and dried to form spherical magnetite particles and the number average particle size of the primary particles. A magnetic iron oxide 1 having a .DELTA..times.200 nm was obtained.
10.0 kg of the magnetic iron oxide 1 was placed in Simpson Mixmara (model MSG-0L, manufactured by Shin Nitto Kogyo Co., Ltd.) and pulverized for 30 minutes.
After that, 95 g of n-decyltrimethoxysilane is added as a silane coupling agent into the apparatus, and the apparatus is operated for 1 hour to hydrophobize the particle surfaces of the magnetic iron oxide 1 with the silane coupling agent. A magnetic body 1 was obtained by
The obtained magnetic substance 1 had a spherical particle shape, and the number average particle diameter of the primary particles was 200 nm.
Table 1 shows the results of the measurement of the content of the hydrophobizing agent for the magnetic material and the moisture adsorption/desorption properties (Z value and YX value) of the magnetic material.

<Manufacturing Example of Magnetic Body 2>
Magnetic Iron Oxide 2, which is spherical magnetite particles and whose primary particles have a number average particle size of 160 nm, was obtained by changing the manufacturing conditions of Magnetic Iron Oxide 1 in the manufacturing example of Magnetic Body 1.
10.0 kg of the magnetic iron oxide 2 was put into Simpson Mixmara (model MSG-0L, manufactured by Shin Nitto Kogyo Co., Ltd.) and pulverized for 30 minutes.
After that, 132 g of n-decyltrimethoxysilane is added as a silane coupling agent into the apparatus, and the apparatus is operated for 1 hour to hydrophobilize the surface of the particles of the magnetic iron oxide 2 with the silane coupling agent. A magnetic body 2 was obtained by
The obtained magnetic substance 2 had a spherical particle shape, and the number average particle diameter of the primary particles was 160 nm.
Table 1 shows the results of the measurement of the content of the hydrophobizing agent for the magnetic material and the moisture adsorption/desorption properties (Z value and YX value) of the magnetic material.

<Manufacturing Example of Magnetic Body 3>
Magnetic Iron Oxide 3, which is spherical magnetite particles and whose primary particles have a number average particle size of 300 nm, was obtained by changing the manufacturing conditions of Magnetic Iron Oxide 1 in the manufacturing example of Magnetic Material 1.
10.0 kg of the magnetic iron oxide 3 was put into Simpson Mixmara (model MSG-0L manufactured by Shin Nitto Kogyo Co., Ltd.), and pulverized for 30 minutes.
After that, 71 g of n-decyltrimethoxysilane is added as a silane coupling agent into the apparatus, and the apparatus is operated for 1 hour to make the particle surfaces of the magnetic iron oxide 3 hydrophobic with the silane coupling agent. A magnetic material 3 was obtained by
The resulting magnetic material 3 had a spherical particle shape, and the number average particle diameter of the primary particles was 300 nm.
Table 1 shows the results of the measurement of the content of the hydrophobizing agent for the magnetic material and the moisture adsorption/desorption properties (Z value and YX value) of the magnetic material.

<Manufacturing Examples of Magnetic Materials 4 to 14>
In the manufacturing example of magnetic substance 1, magnetic substance 1 was used except that the type and amount of addition of the hydrophobizing agent were adjusted so that the content of the hydrophobizing agent in the obtained magnetic substance was the value shown in Table 1. Magnetic bodies 4 to 14 were obtained in the same manner as in the production example of . Physical properties are shown in Table 1.

<Manufacturing Example of Magnetic Body 15>
In the manufacturing example of the magnetic substance 1, instead of the Simpson Mix Mara, a Henschel mixer (manufactured by Nippon Coke Kogyo Co., Ltd. model FM-10
) was used, the magnetic material 15 was obtained in the same manner as in the manufacturing example of the magnetic material 1. Physical properties are shown in Table 1.

<Manufacturing Example of Magnetic Body 16>
A ferrous sulfate aqueous solution is mixed with 1.0 equivalent of a caustic soda solution with respect to iron ions (containing 1% by mass of sodium hexametaphosphate in terms of P in terms of Fe), and an aqueous solution containing ferrous hydroxide is prepared. prepared. While maintaining the pH of the aqueous solution at 9, air was blown into the aqueous solution and an oxidation reaction was performed at 80° C. to prepare a slurry solution for generating seed crystals.
Then, an aqueous solution of ferrous sulfate was added to the slurry so that the amount of alkali (sodium component of caustic soda) was 1.0 equivalent. The pH of the slurry liquid was maintained at pH 8, and the oxidation reaction was advanced while blowing air.
As a silane coupling agent, 1.32 parts of isobutyltrimethoxysilane (4 carbon atoms) was added to 100 parts of the obtained magnetic iron oxide 4:100 parts, thoroughly stirred, and hydrophobized by a wet method. went.
The resulting hydrophobized magnetic iron oxide particles were washed, filtered, and dried by a conventional method, and after crushing the aggregated particles, a heat treatment was performed at a temperature of 70° C. for 5 hours to obtain the magnetic material 16. .
The particle shape of the magnetic material was spherical, and the number average particle diameter of the primary particles was 260 nm. Physical properties are shown in Table 1.

表中、Ｚ及びＹ－Ｘの単位は、ｍｇ／ｇである。

In the table, the units of Z and YX are mg/g.

<Production example of polyester resin>
・Terephthalic acid 30.0 parts ・Trimellitic acid 5.0 parts ・Bisphenol A ethylene oxide (2 mol) adduct 160.0 parts ・Dibutyltin oxide 0.1 part Nitrogen gas was introduced into the inside of the flask to keep it in an inert atmosphere, and the temperature was raised while stirring. Thereafter, the temperature was raised from 140° C. to 220° C. over about 12 hours to carry out a polycondensation reaction, and then the polycondensation reaction was allowed to proceed while reducing the pressure in the range of 210° C. to 240° C. to obtain a polyester resin.
The polyester resin had a number average molecular weight (Mn) of 21,200, a weight average molecular weight (Mw) of 84,500, and a glass transition temperature (Tg) of 79.5°C.

<Production Example of Toner Particle 1>
After adding 450 parts of 0.1 mol/L-Na ₃ PO ₄ aqueous solution to 720 parts of ion-exchanged water and heating to a temperature of 60° C., 67.7 parts of 1.0 mol/L-CaCl ₂ aqueous solution was added to stabilize the dispersion. An aqueous medium containing the agent was obtained.
・Styrene 78.00 parts ・n-Butyl acrylate 22.00 parts ・Polypropylene glycol #400 diacrylate (APG400) 1.70 parts ・Polyester resin 4.00 parts ・Magnetic substance 1 70.00 parts They were uniformly dispersed and mixed using Nippon Coke Kogyo Co., Ltd.).
The obtained monomer composition was heated to a temperature of 60° C., and the following materials were mixed and dissolved therein to obtain a polymerizable monomer composition.
・ Negative charge control agent T-77 (manufactured by Hodogaya Chemical Industry) 1.00 parts ・ Release agent 5.00 parts (Fischer-Tropsch wax (HNP-51: manufactured by Nippon Seiro Co., Ltd.))
- Polymerization initiator 10.00 parts (t-butyl peroxypivalate (25% toluene solution))
A polymerizable monomer composition was added to an aqueous medium, and stirred at 22,000 rpm for 15 minutes at a temperature of 60° C. in a nitrogen atmosphere with a TK-type homomixer (Tokushu Kika Kogyo Co., Ltd.) to granulate. . After that, the mixture was stirred with a paddle stirring blade, and a polymerization reaction was carried out at a reaction temperature of 70° C. for 300 minutes.
Thereafter, the resulting suspension was cooled to room temperature at a rate of 3° C. per minute, and hydrochloric acid was added to dissolve the dispersion stabilizer. Tables 2 and 3 show the formulation and physical properties of the toner particles 1 thus obtained.

<Production Examples of Toner Particles 2 to 20>
Toner Particles 2 to 2 are prepared in the same manner as in Toner Particle 1 Production Example, except that the type and number of parts of the magnetic material and the type and number of parts of the cross-linking agent are changed as shown in Table 2. Got 20. Tables 2 and 3 show the formulation and physical properties.

<Production Example of Toner Particles 21>
Toner particles 21 were obtained in the same manner as in Production Example of Toner Particles 12 except that the magnetic material 12 was used. Tables 2 and 3 show the formulation and physical properties of the toner particles 21.

<Production Example of Toner Particles 22>
Toner particles 22 were obtained in the same manner as in Production Example of Toner Particles 13 except that Magnetic Body 13 was used in Production Example of Toner Particles 10 . Tables 2 and 3 show the formulation and physical properties of the toner particles 22 .

<Production Example of Toner Particles 23>
Toner particles 23 were obtained in the same manner as in Production Example of Toner Particles 23 except that Magnetic Body 14 was used in Production Example of Toner Particles 18 . Tables 2 and 3 show the formulation and physical properties of the toner particles 23 .

<Production Example of Toner Particles 24>
850 parts of 0.1 mol/L-Na ₃ PO ₄ aqueous solution was added to a vessel equipped with a high-speed stirring device Clearmix (manufactured by M Technic Co., Ltd.) and heated to 60° C. while stirring at a rotation peripheral speed of 33 m/s. I warmed up. 68 parts of a 1.0 mol/L-CaCl ₂ aqueous solution was added thereto to prepare an aqueous medium containing a very small amount of a poorly water-soluble dispersant Ca ₃ (PO ₄ ) ₂ .
A solution was prepared by mixing and dissolving the following materials using a propeller stirrer. In addition, when mixing the following materials, the rotation speed of the stirrer was set to 100 r/min.
・Styrene: 75.0 parts ・n-Butyl acrylate: 25.0 parts ・Polyester resin: 10.0 parts ・Magnetic substance 15: 100.0 parts ・Iron complex of monoazo dye (T-77: manufactured by Hodogaya Chemical Co., Ltd.) : 1.0 parts Hydrocarbon wax HNP-51 (manufactured by Nippon Seiro Co., Ltd.): 15.0 parts After heating the mixture to a temperature of 60 ° C., it was added to a TK type homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) Then, the rotation speed of the stirrer was set to 9000 r/min, and the mixture was stirred to dissolve and disperse the solid content.
10.0 parts of 2,2′-azobis(2,4-dimethylvaleronitrile) as a polymerization initiator was added to this and dissolved in the mixture to prepare a polymerizable monomer composition. Next, the polymerizable monomer composition was put into the aqueous medium, heated to 60° C., and then granulated for 15 minutes while rotating CLEARMIX at a rotation peripheral speed of 33 m/s.
After that, the mixture was transferred to a propeller stirrer and stirred at 100 revolutions/min and reacted at a temperature of 70° C. for 5 hours, then heated to 85° C. and further reacted for 4 hours to produce magnetic toner particles. . After completion of the polymerization reaction, residual monomers were removed under heating and reduced pressure, and after cooling, hydrochloric acid was added to lower the pH to 2.0 or less, thereby dissolving the inorganic fine particles. Further, after repeating washing with water several times, the toner particles 24 were obtained by drying with a dryer at 40° C. for 72 hours and then classifying with a multi-division classifier utilizing the Coanda effect.

<Production Example of Toner Particles 25>
Toner particles 25 were obtained in the same manner as in Production Example of Toner Particles 12 except that Magnetic Body 16 was used. Tables 2 and 3 show the formulation and physical properties of the toner particles 25.

<Production Example of Toner Particles 26>
After adding 450 parts of 0.1 mol/L-Na ₃ PO ₄ aqueous solution to 720 parts of ion-exchanged water and heating to a temperature of 60° C., 67.7 parts of 1.0 mol/L-CaCl ₂ aqueous solution was added to stabilize the dispersion. An aqueous medium containing the agent was obtained.
・Styrene 78.00 parts ・n-Butyl acrylate 22.00 parts ・Polypropylene glycol #400 diacrylate (APG400) 1.70 parts The above formulation was uniformly dispersed and mixed using an attritor (Nippon Coke Industry Co., Ltd.). .
The obtained monomer composition was heated to a temperature of 60° C., and the following materials were mixed and dissolved therein to obtain a polymerizable monomer composition.
- Polymerization initiator 10.00 parts (t-butyl peroxypivalate (25% toluene solution))
A polymerizable monomer composition was added to an aqueous medium, and stirred at 22,000 rpm for 15 minutes at a temperature of 60° C. in a nitrogen atmosphere with a TK-type homomixer (Tokushu Kika Kogyo Co., Ltd.) for granulation. . After that, the mixture was stirred with a paddle stirring blade, and a polymerization reaction was carried out at a reaction temperature of 70° C. for 300 minutes.
Thereafter, the resulting suspension was cooled to room temperature at a rate of 3° C. per minute, and hydrochloric acid was added to dissolve the dispersant.
・Resin particles 1 101.50 parts ・Magnetic substance 1 70.00 parts ・Polyester resin 4.00 parts ・Negative charge control agent T-77 (manufactured by Hodogaya Chemical Industry Co., Ltd.) 1.00 parts ・Release agent 5.00 parts (Fischer-Tropsch wax (HNP-51: manufactured by Nippon Seiro Co., Ltd.))
After pre-mixing the above materials with an FM mixer (manufactured by Nippon Coke Kogyo Co., Ltd.), a twin-screw extruder (trade name: PCM-30, manufactured by Ikegai Ironworks Co., Ltd.) is used to make the melt temperature at the discharge port 150 ° C. The temperature was set and melt-kneaded so that
The resulting kneaded product was cooled, roughly pulverized with a hammer mill, and then finely pulverized with a pulverizer (trade name: Turbo Mill T250, manufactured by Turbo Kogyo Co., Ltd.).
The resulting finely pulverized product was classified using a multi-division classifier utilizing the Coanda effect to obtain toner particles 26 . Tables 2 and 3 show the formulation and physical properties of the toner particles 26 thus obtained.

表中、ＨＤＤＡは１，６―ヘキサンジオールジアクリレートである。

In the table, HDDA is 1,6-hexanediol diacrylate.

<Manufacturing Example of Toner 1>
To 100 parts of toner particles 1, 0.3 part of sol-gel silica fine particles having a primary particle number average particle size of 100 nm was added and mixed using an FM mixer (manufactured by Nippon Coke Industry Co., Ltd.).
Thereafter, silica fine particles having a primary particle number average particle diameter of ¹² nm were further treated with hexamethyldisilazane and then treated with silicone oil, and the BET specific surface area after treatment was 0.6. parts were added and similarly mixed using an FM mixer (manufactured by Nippon Coke Kogyo Co., Ltd.) to obtain Toner 1.

<Example 1>
An HP printer (HP LaserJet Pro M506dn) was modified to increase the process speed by 1.3 times to obtain an electrophotographic apparatus for evaluation.
In addition, CF287X was used as a toner cartridge, and 680 g of toner 1 was filled, and the following evaluation was performed. Table 4 shows the evaluation results.

<Evaluation 1: Evaluation of halftone density uniformity (under low temperature and low humidity environment (LL environment))>
The halftone density uniformity was evaluated under a low-temperature, low-humidity environment (temperature 15.0° C., relative humidity 10.0%), which is a severe environment where charge-up tends to cause differences in charge distribution on the developing sleeve.
Assuming a long-term endurance test, evaluation was performed in a mode in which the print rate is lower than usual and the toner deterioration is severe. Specifically, a horizontal line pattern with a printing rate of 1% for horizontal lines of 2 dots was set as one job for each sheet, and a durability test was performed on a total of 20,000 sheets.
As the evaluation paper, rough paper COTTON BOND LIGHT COCKLE (basis weight: 75 g LTR, length: 279 mm, width: 216 mm) was used.
Then, on the 1st and 20000th sheets, the top margin is 10 mm and the horizontal line spacing is 10 mm. After the top margin, a solid black patch (30 mm long × 100 mm wide) is placed left aligned, and the right side is a white image, and then solid black. After patching, an image having a halftone portion formed of horizontal isolated dots of 229 mm long by 196 mm was output (dot printing rate 15%). Then, the 20000th image was evaluated as follows.
Then, the density of the halftone portion of the image was measured at 100 points using a Macbeth reflection densitometer (manufactured by Macbeth), the maximum value and the minimum value were obtained, the difference was obtained, and evaluation was performed according to the following criteria. . C or more was judged to be good.
[Evaluation criteria]
A: Density difference less than 0.05 B: Density difference 0.05 to less than 0.10 C: Density difference 0.10 to less than 0.15 D: Density difference 0.15 or more

<Evaluation 2: Evaluation of dot reproducibility (under high temperature and high humidity environment (HH environment))>
Evaluation of the dot reproducibility of the halftone image was conducted under a high temperature and high humidity environment (temperature: 32.5°C, relative humidity: 85.5°C), which is a severe environment in which the chargeability of the toner tends to decrease and unevenness in developing and transferability tends to occur. 0%).
Assuming a long-term endurance test, evaluation was performed in a mode in which the print rate is lower than usual and the toner deterioration is severe. Specifically, a horizontal line pattern in which a horizontal line of 2 dots has a print rate of 1% was set as one job for each sheet, and a durability test was performed on a total of 20,000 sheets.
As the evaluation paper, rough paper COTTON BOND LIGHT COCKLE (basis weight 75 g LTR, length 279 mm, width 216 mm) was used.
Then, on the 1st and 20000th sheets, an image having a halftone portion formed of horizontal isolated dots of 259 mm×196 mm with a tip margin of 10 mm and a horizontal line interval of 10 mm was output (dot printing rate of 15%). Then, the 20000th image was evaluated as follows.
100 isolated dots of the image were randomly observed using a magnifying glass, and the minor axis and major axis of each dot were measured to obtain the ratio of the major axis to the minor axis (the value obtained by dividing the major axis by the minor axis). Then, dot reproducibility was determined according to the following criteria using the maximum value of the ratio of the major axis to the minor axis among the 100 isolated dots. C or more was judged to be good.
A. The maximum value of the ratio of the major axis to the minor axis is less than 1.10B. C. The maximum value of the ratio of the major axis to the minor axis is 1.10 or more and less than 1.20. D. The maximum value of the ratio of the major axis to the minor axis is 1.20 or more and less than 1.30. The maximum value of the ratio of the major axis to the minor axis is 1.30 or more

<Evaluation 3: Halftone density retention rate (under high temperature and high humidity environment)>
Evaluation of the halftone density retention rate of the halftone image is performed under a high temperature and high humidity environment (temperature: 32.5°C, relative humidity: 85.0°C), which is a severe environment in which the chargeability of the toner tends to decrease and the halftone density tends to decrease. %).
Assuming a long-term endurance test, evaluation was performed in a mode in which the print rate is lower than usual and the toner deterioration is severe. Specifically, a horizontal line pattern with a printing rate of 1% for horizontal lines of 2 dots was set as one job for each sheet, and a durability test was performed on a total of 20,000 sheets.
As the evaluation paper, rough paper COTTON BOND LIGHT COCKLE (basis weight: 75 g LTR, length: 279 mm, width: 216 mm) was used.
Then, on the 1st and 20000th sheets, an image having a halftone portion formed of horizontal isolated dots of 259 mm×196 mm with a tip margin of 10 mm and a horizontal line interval of 10 mm was output (dot printing rate of 15%). Then, the following evaluations were made for both the images of the 1st sheet and the 20,000th sheet.
Then, for both the 1st sheet and the 20,000th sheet of the image, the density of the halftone portion was measured by 10 points with a Macbeth reflection densitometer (manufactured by Macbeth), and the average value was the halftone value of each image. concentration.
By dividing the halftone density of the 20,000th image by the halftone density of the first image and multiplying by 100, the halftone density retention rate was obtained and evaluated according to the following criteria. C or more was judged to be good.
[Evaluation criteria]
A: Halftone density retention rate of 90% or more B: Halftone density retention rate of 85% or more and less than 90% C: Halftone density retention rate of 80% or more and less than 85% D: Halftone density retention rate of less than 80%

<Evaluation 4: Evaluation of Halftone Density Uniformity in Cryogenic Environment (Under Cryogenic Environment)>
Halftone density uniformity in a cryogenic environment was measured in a cryogenic environment (7.0° C. temperature, 30.0% relative humidity), which is an environment in which minute cracks on the surface of toner particles and internal strain are likely to occur. Ta.
Specifically, in the durability test, a total of 20,000 sheets were printed with a horizontal line pattern having a printing rate of 2% for horizontal lines of 2 dots as one job for each sheet.
As the evaluation paper, rough paper COTTON BOND LIGHT COCKLE (basis weight: 75 g LTR, length: 279 mm, width: 216 mm) was used.
Then, on the 1st and 20000th sheets, the top margin is 10 mm and the horizontal line spacing is 10 mm. After the top margin, a solid black patch (30 mm long × 100 mm wide) is placed left aligned, and the right side is a white image, and then solid black. After patching, an image having a halftone portion formed of horizontal isolated dots of 229 mm long by 196 mm was output (dot printing rate 15%). Then, the 20000th image was evaluated as follows.
Then, the density of the halftone portion of the image was measured at 100 points with a Macbeth reflection densitometer (manufactured by Macbeth), the maximum value and the minimum value were obtained, and the difference was obtained. Evaluation was performed according to the following criteria. Ta. C or more was judged to be good.
[Evaluation criteria]
A: Density difference less than 0.05 B: Density difference 0.05 to less than 0.10 C: Density difference 0.10 to less than 0.15 D: Density difference 0.15 or more

<Evaluation 5: Evaluation of dot reproducibility in cryogenic environment (under cryogenic environment)>
The dot reproducibility in an extremely low temperature environment was measured in an extremely low temperature environment (7.0° C. temperature, 30.0% relative humidity), which is an environment in which minute cracks on the toner surface and internal strain are likely to occur.
Specifically, in the durability test, a total of 20,000 sheets were printed with a horizontal line pattern having a printing rate of 2% for horizontal lines of 2 dots as one job for each sheet.
As the evaluation paper, rough paper COTTON BOND LIGHT COCKLE (basis weight: 75 g LTR, length: 279 mm, width: 216 mm) was used.
Then, on the 1st and 20000th sheets, an image having a halftone portion formed of horizontal isolated dots of 259 mm×196 mm with a tip margin of 10 mm and a horizontal line interval of 10 mm was output (dot printing rate of 15%). Then, the 20000th image was evaluated as follows.
100 isolated dots of the image were randomly observed using a magnifying glass, and the minor axis and major axis of each dot were measured to obtain the ratio of major axis to minor axis (the value obtained by dividing the major axis by the minor axis). Then, dot reproducibility was determined according to the following criteria using the maximum value of the ratio of the major axis to the minor axis among the 100 isolated dots. C or more was judged to be good.
A. The maximum value of the ratio of the major axis to the minor axis is less than 1.10B. C. The maximum value of the ratio of the major axis to the minor axis is 1.10 or more and less than 1.20. D. The maximum value of the ratio of the major axis to the minor axis is 1.20 or more and less than 1.30. The maximum value of the ratio of the major axis to the minor axis is 1.30 or more

<Evaluation 6: Evaluation of dot reproducibility after long-term standing (under high-temperature and high-humidity environment)>
After being left for 30 days in a high-temperature and high-humidity environment (temperature: 32.5° C., relative humidity: 85.0%), halftone image dot reproducibility was evaluated in the same environment.
Leaving the toner in a high-temperature, high-humidity environment for a long period of time tends to lower the chargeability of the toner compared to evaluation in a normal high-temperature, high-humidity environment.
Specifically, in the durability test, a total of 10,000 sheets were printed with a horizontal line pattern having a print rate of 2% for horizontal lines of 2 dots as one job for each sheet.
As the evaluation paper, rough paper COTTON BOND LIGHT COCKLE (basis weight 75 g LTR, length 279 mm, width 216 mm) was used.
Then, on the 1st and 10000th sheets, an image having a halftone portion formed by horizontal isolated dots of 259 mm×196 mm with a tip margin of 10 mm and a horizontal line interval of 10 mm was output (dot printing rate of 15%). The 10000th image was evaluated as follows.
100 isolated dots of the image were randomly observed using a magnifying glass, and the minor axis and major axis of each dot were measured to obtain the ratio of the major axis to the minor axis (the value obtained by dividing the major axis by the minor axis). Then, dot reproducibility was determined according to the following criteria using the maximum value of the ratio of the major axis to the minor axis among the 100 isolated dots. C or more was judged to be good.
A. The maximum value of the ratio of the major axis to the minor axis is less than 1.10B. C. The maximum value of the ratio of the major axis to the minor axis is 1.10 or more and less than 1.20. D. The maximum value of the ratio of the major axis to the minor axis is 1.20 or more and less than 1.30. The maximum value of the ratio of the major axis to the minor axis is 1.30 or more

<Evaluation 7: Halftone density retention rate after long-term storage (under high-temperature and high-humidity environment)>
After being left for 30 days in a high-temperature and high-humidity environment (temperature: 32.5° C., relative humidity: 85.0%), the density retention rate of the halftone image was evaluated in the same environment.
This is a severe evaluation condition in which the chargeability of the toner tends to decrease and the density retention rate tends to decrease when the toner is left for a long period of time in a high temperature and high humidity environment, as compared to evaluation in a normal high temperature and high humidity environment.
Specifically, in the durability test, a total of 10,000 sheets were printed with a horizontal line pattern having a print rate of 2% for horizontal lines of 2 dots as one job for each sheet.
As the evaluation paper, rough paper COTTON BOND LIGHT COCKLE (basis weight 75 g LTR, length 279 mm, width 216 mm) was used.
Then, on the first sheet and the 10000th sheet, an image having a halftone portion formed of horizontal isolated dots of 259 mm×196 mm with a tip margin of 10 mm and a horizontal line interval of 10 mm was output (dot printing rate of 15%). Then, the following evaluations were made for both the first image and the 10,000th image.
Then, for both the 1st and 10000th images, the density of the halftone portion was measured by 10 points with a Macbeth reflection densitometer (manufactured by Macbeth), and the average value was taken as the halftone density of each image. did.
Then, the halftone density of the 10,000th image was divided by the halftone density of the first image and multiplied by 100 to obtain the halftone density retention rate, which was evaluated according to the following criteria. C or more was judged to be good.
[Evaluation criteria]
A: Halftone density retention rate of 90% or more B: Halftone density retention rate of 85% or more and less than 90% C: Halftone density retention rate of 80% or more and less than 85% D: Halftone density retention rate of less than 80%

<Manufacturing Examples of Toners 2 to 26>
Toners 2 to 26 were obtained in the same manner as in Production Example of Toner 1, except that the toner particles shown in Table 3 were used.

<Examples 2 to 20, Comparative Examples 1 to 6>
The same evaluation as in Example 1 was performed using toners 2 to 26. Table 4 shows the evaluation results. Examples 8 to 10, 19 and 20 are hereinafter referred to as Reference Examples 8 to 10, 19 and 20, respectively.

Claims (4)

A toner containing toner particles containing a binder resin and a magnetic material,
the binder resin contains a vinyl resin having an ether structure,
The vinyl resin having an ether structure is a vinyl resin crosslinked with a crosslinking agent represented by the following formula (4),

(In formula (4), m+n is an integer of 2 or more, R _{1 and R 4 independently represent H or CH 3 , R 2 and R 3 independently} represent _a straight chain _having 2 _to 12 carbon atoms or represents a hydrocarbon group having a branched chain.)
The magnetic material is a hydrophobized magnetic material treated with a hydrophobizing agent,
The hydrophobizing agent contains an alkyltrialkoxysilane coupling agent represented by the following formula (I),
C _p H _2p+1 -Si-(OC _q H _2q+1 ) ₃ (I)
(In formula (I), p represents an integer of 8 or more and 16 or less, and q represents an integer of 1 or more and 3 or less.)
satisfying the following (1) and (2) in the moisture adsorption/desorption curve obtained by measuring the vapor adsorption amount of the magnetic material,
(1) 1.7≤Z≤6.0
(2) Y−X≧0.10
X: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the adsorption curve
Y: Water adsorption amount (mg/g) at 30°C and 10% relative humidity in the desorption curve
Z: Water adsorption amount (mg/g) at 30°C and 100% relative humidity in the adsorption curve
In cross-sectional observation of the toner with a transmission electron microscope,
The magnetic material is present at 60 area % or more and 100 area % or less in a region of 10% or less of the distance from the contour of the cross section of the toner particle to the center of gravity of the cross section,
In cross-sectional observation of the toner with a transmission electron microscope,
When A1 is the area ratio occupied by the magnetic material in the region of 200 nm or less from the contour of the cross section of the toner particle in the direction of the center of gravity of the cross section,
The area ratio A1 is 38% or more and 85% or less,
The toner hardness A (N/m) and the toner hardness B (N/m) of the toner obtained by the nanoindentation method satisfy the following formula (3),
The ratio (E2/E1) of the abundance (E2) of the iron element to the abundance (E1) of the carbon element present on the surface of the toner particles measured by X-ray photoelectron spectroscopy is 0.00100 or less. A toner characterized by:
B/A≧1.20 (3)
(In formula (3), the hardness A of the toner is a load-displacement curve obtained by measuring the toner at a load application speed of 0.83 μN/sec, with the vertical axis representing the load a (mN) and the horizontal axis representing the displacement The average value of the slope in the displacement region of 0.00 μm or more and 0.20 μm or less when the amount is b (μm),
The hardness B of the toner is a load-displacement curve obtained by measuring the toner under the condition of a load application speed of 2.50 μN/sec. is the average value of the slope in the displacement region of 0.00 μm or more and 0.20 μm or less. ) 2. The toner according to claim 1, wherein said toner hardnesses A and B satisfy the following formula (4).
B/A≧1.30 (4) 3. The toner according to claim 1 , wherein the treatment amount of the hydrophobizing agent is 0.5 parts by mass or more and 1.5 parts by mass or less with respect to 100 parts by mass of the untreated magnetic material. The toner according to any one of claims 1 to 3 , wherein the toner comprises the toner particles and an external additive.

Images