JP7555746B2 - Toner manufacturing method - Google Patents

Description

The present invention relates to a toner used in electrophotography, electrostatic recording, electrostatic printing, and toner jet methods, and a method for producing the toner.

In recent years, full-color electrophotographic copiers have come into widespread use, and there is an increasing demand for energy-saving and high productivity. In addition, there is also a demand for high-quality images approaching those of offset printing, and there is a demand for the development of high-quality toner technology to achieve these demands.
In order to save energy, technology that melts toner quickly at low temperatures in the fixing process is being studied. In order to improve the low-temperature fixing ability of toner, there is a method of lowering the glass transition point or softening point of the binder resin of the toner and using a binder resin that has sharp melting properties. In recent years, many toners that contain crystalline polyester as a resin with even sharper melting properties have been proposed.
For high productivity, various toners are being studied to shorten the time for various controls immediately after power-on, during one job, and between jobs. For example, studies are being conducted to create toners whose charging properties do not decrease even when left in a high-temperature, high-humidity environment, and toners whose fixing temperature range is wide and which do not wrap around a fixing member even at high temperatures.
As a toner that does not wrap around a fixing member even at high temperatures, for example, Patent Document 1 proposes a toner that contains two types of polyester resins and is characterized in that the degree of uneven distribution of wax in the depth direction of the toner from the toner surface toward the toner center is controlled. The toner of Patent Document 1 has a large amount of wax present near the toner particle surface, so the wax effectively seeps out during fixing, improving the release property and improving the anti-wrapping property. However, the inventor's research has revealed that when an image with a low printing ratio is output for a long period of time, the graininess of the image increases, making it difficult to obtain a high-quality image.
It has been found that the main cause of graininess in images is the increase in the adhesion between toner particles and a transfer member, which reduces the uniformity of transfer, and techniques for reducing this have been studied. For example, as a proposal for reducing the adhesion to the member, studies have been conducted on covering toner particles with an external additive of inorganic fine particles at a high coverage rate, reducing the adhesion by the spacer effect of the fine particles, and covering core particles with a shell that has a lower adhesion than the core particles. For example, Patent Document 2 proposes a toner having toner particles with a coating layer containing an organosilicon polymer having a specific structure.

JP 2012-83749 A JP 2016-21041 A

The present inventors have been studying a toner that has anti-fixing wrapping properties, can reduce the adhesion force with a transfer member, and can obtain a high-quality image with little graininess. As a result, it has been found that the adhesion between the core particles, which have a lot of wax near the surface of the toner particles as described in Patent Document 1, and the organosilicon polymer is low. The organosilicon polymer detached from the core particles migrates to the photoreceptor surface in the electrophotographic development process, and further, a part of it slips through the cleaning blade in the cleaning process. This tendency is more pronounced in low-humidity environments. As a result, a difference in latent image potential occurs in the next charging process between a portion where the organosilicon polymer has a lot of slip-through and a portion where it has a little, which may appear as a difference in image density (hereinafter, also referred to as an external additive ghost).
The object of the present invention is to provide a toner which has solved the above problems, specifically, a coating layer containing an organosilicon polymer which has high adhesion even to core particles which have a large amount of wax near the surface, which has excellent anti-wrapping properties and charge stability, and which can provide high quality images with little graininess over a long period of time, and which can suppress external additive ghosts.

The present invention relates to a method for producing a toner having toner particles which have core particles containing a binder resin and a wax, and which have inorganic oxide fine particles on the surfaces of the core particles and a coating layer which contains an organosilicon polymer and which coats the core particles, the method comprising the steps of :
The core particles satisfy the following relationship, where the endothermic heat of the endothermic peak derived from the wax measured by differential scanning calorimetry (DSC) is Qi (J/g) and the endothermic heat of the endothermic peak derived from the wax measured by DSC after the core particles are treated with hexane is Qh (J/g):
0.7≦Qi−Qh≦20.0
The organosilicon polymer has a partial structure represented by the following formula (T3):
In a ^29Si -NMR measurement of the tetrahydrofuran insoluble matter of the toner particles, the ratio [ST3] of the peak area of the partial structure represented by the following formula (T3) to the total peak area of the organosilicon polymer satisfies the relationship ST3≧0.05,
R-Si(O _1/2 ) ₃ (T3)
(In formula (T3), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.)
the inorganic oxide fine particles are thermally fixed to the surface of the core particles,
a step of adhering the inorganic oxide fine particles to the surface of the core particles containing the binder resin and the wax;
and dispersing the core particles having the inorganic oxide fine particles attached thereto in an aqueous medium.
a step of coating the surface of the core particles to which the inorganic oxide fine particles are attached with the organosilicon polymer,
The method for producing a toner is characterized by comprising, after the step of adhering the inorganic oxide fine particles to the surface of the core particles, a step of treating the core particles to which the inorganic oxide fine particles are adhered with hot air .

The toner of the present invention has a coating layer containing an organosilicon polymer that has high adhesion even to core particles that have a lot of wax near the surface, and can provide a toner that has excellent fixation wrap-around resistance, development durability, and can produce high-quality images with little graininess over a long period of time, while also suppressing external additive ghosts.

FIG. 2 is an explanatory diagram of a surface treatment device suitable for thermally fixing inorganic oxide fine particles to the surface of a toner core particle. 2 is a ²⁹ Si-NMR measurement chart of the toner particles of the present invention.

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

In the present invention, "monomer unit" refers to the reacted form of a monomer substance in a polymer.

A crystalline resin is a resin that shows a clear endothermic peak in differential scanning calorimetry (DSC) measurements.

The toner of the present invention is a toner having core particles containing a binder resin and a wax, and having inorganic oxide fine particles on the surface of the core particles, and a coating layer containing an organosilicon polymer coating the core particles,
The core particles satisfy the following relationship, where the endothermic heat of the endothermic peak derived from the wax measured by differential scanning calorimetry (DSC) is Qi (J/g) and the endothermic heat of the endothermic peak derived from the wax measured by DSC after the core particles are treated with hexane is Qh (J/g):
0.7≦Qi−Qh≦20.0
The organosilicon polymer has a partial structure represented by the following formula (T3):
In a ^29Si -NMR measurement of the tetrahydrofuran insoluble matter of the toner particles, the ratio [ST3] of the peak area of the partial structure represented by the following formula (T3) to the total peak area of the organosilicon polymer satisfies the relationship ST3≧0.05,
R-Si(O _1/2 ) ₃ (T3)
(In formula (T3), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.)
The toner is characterized in that the inorganic oxide fine particles are thermally fixed to the surface of the core particles.

The present inventors believe that the mechanism by which the effects of the present invention are realized is as follows: The surface of the core particles, which has a large amount of wax near the surface, is highly hydrophobic. On the other hand, the coating layer containing the organosilicon polymer of the present invention that coats the core particles has a structure of R-Si(O1 _/ 2) ₃ (T3)
In this structure, R is an alkyl group or a phenyl group having 1 to 6 carbon atoms, and is relatively hydrophobic, but since it also contains a large amount of hydrophilic Si-OH groups, the coating layer as a whole is hydrophilic. Therefore, it is believed that the core particle and the coating layer have low wettability and low adhesion due to the large difference in polarity.

The toner particles of the present invention are characterized in that inorganic oxide fine particles are thermally fixed to the surface of the core particles. Fixation of inorganic oxide fine particles by heat improves the adhesion of the inorganic oxide fine particles to the surface of the core particles, and can also suppress the detachment of the inorganic oxide fine particles even after endurance testing. In addition, the inorganic oxide fine particles contain oxygen atoms with high electronegativity. Therefore, the oxygen atoms of the inorganic oxide fine particles fixed to the hydrophobic wax, which has a hydrophobic site in abundance near the surface of the core particles, and the hydrophilic hydroxyl groups of the silanol sites of the organosilicon polymer exhibit affinity through an interaction such as hydrogen bonding, which is thought to be the effect of adhering the organosilicon polymer to the core particles in which a large amount of wax is present.

The core particle of the toner particle of the present invention is characterized in that, when the endothermic heat of the endothermic peak derived from the wax measured by differential scanning calorimetry (DSC) is Qi (J/g), and the endothermic heat of the endothermic peak derived from the wax measured by DSC after hexane treatment of the core particle is Qh (J/g), the core particle satisfies the following relational expression:
0.7≦Qi−Qh≦20.0

Qi indicates the amount of heat absorption derived from the wax present throughout the core particle. On the other hand, Qh indicates the amount of heat absorption derived from the wax present inside the core particle after the wax present near the core particle surface is dissolved in hexane and removed by treating the core particle with hexane. Therefore, Qi-Qh is a parameter indicating the amount of heat absorption derived from the wax present near the core particle surface, and the larger the value of Qi-Qh, the more wax is present near the core particle surface, which means that the wax melts quickly in the fixing process and a high release effect can be achieved. When Qi-Qh is in the above range, both high anti-fixing wrap-around properties and non-image graininess after durability can be achieved. When Qi-Qh exceeds 20.0, non-image graininess after durability deteriorates. It is preferably 0.7 to 10.0, more preferably 1.0 to 7.0, and even more preferably 1.8 to 5.0.

The toner particles of the present invention are characterized in that, when the endothermic heat of the endothermic peak derived from the wax measured by differential scanning calorimetry (DSC) is Qit, and the endothermic heat of the endothermic peak derived from the wax measured by DSC after hexane treatment is Qht (J/g), the following relationship is satisfied.
0.8≦Qit-Qht≦21.0

When Qit-Qht is in the above range, it is possible to achieve both high resistance to fixing wrap and low image graininess after durability testing.

In addition, it is preferable that the core particles of the toner particles of the present invention have a (Qi-Qh)/Qi value in the range of 0.05 or more and 0.90 or less. (Qi-Qh)/Qi is a parameter that indicates the proportion of wax present near the surface in the core particle, and a high value indicates that there is more wax present near the surface than inside the core particle. When the (Qi-Qh)/Qi value is within the above range, it is possible to achieve both high anti-wrapping properties and high levels of external additive ghost suppression effect and non-image graininess after durability testing.

The toner particles of the present invention preferably have a value of (Qit-Qht)/Qit in the range of 0.06 to 0.95, more preferably 0.09 to 0.85, and even more preferably 0.15 to 0.70. Even more preferably 0.21 to 0.42.

The preferred range of Qi is 3.0 or more and 40.0 or less, from the viewpoint of making it easier to control the ranges of Qi-Qh and (Qi-Qh)/Qi within the above ranges. It is more preferably 3.0 or more and 30.0 or less, and even more preferably 5.0 or more and 15.0 or less.

Qi can be controlled by the type of wax, the amount added, etc.

Qi-Qh can be controlled by the type and amount of wax, as well as the method of manufacturing the core particles. When forming toner particles in water using methods such as the dissolution suspension method, emulsion aggregation method, and suspension polymerization method, hydrophilic materials tend to gather on the surface of the core particles, and hydrophobic wax tends to be unevenly distributed inside the toner particles. For this reason, it is preferable to form the core particles by a pulverization method after melt kneading. Furthermore, using the device shown in Figure 1 (details will be described later) and using core particles treated with hot air, the wax is unevenly distributed on the surface by the hot air treatment, and it is particularly preferable because it is easy to control Qi-Qh within the above range. Qi-Qh can be controlled by the temperature of the hot air, the flow rate of the hot air, the amount of core particles processed per hour, etc. In addition, when a wax dispersant is used, the speed at which the wax moves due to the hot air changes, so the value of Qi-Qh can be changed.

The toner particles of the present invention have a coating layer containing an organosilicon polymer coating a core particle, and the organosilicon polymer has a partial structure represented by the following formula (T3):
The toner particles are characterized in that, in a ^29Si -NMR measurement of the tetrahydrofuran (THF) insoluble matter, the ratio [ST3] of the peak area of the partial structure represented by the following formula (T3) to the total peak area of the organosilicon polymer satisfies the relationship ST3≧0.05.
R-Si(O _1/2 ) ₃ (T3)
(In formula (T3), R represents an alkyl group or a phenyl group having 1 to 6 carbon atoms.)

In the toner particles of the present invention, when the THF-insoluble portion is measured by ^29Si -NMR, the ratio [ST3] of the peak area of the partial structure represented by the above formula (T3) (hereinafter also referred to as the T3 structure) to the total peak area of the organosilicon polymer satisfies the relationship ST3≧0.05, so that the surface free energy of the toner particle surface can be lowered, the adhesive force to the transfer member can be reduced, and a good image with little graininess can be obtained. If ST3 is less than 0.05, the graininess of the image deteriorates. A more preferable range for ST3 is 0.50 or more and 0.80 or less.

The proportion of the T unit structure can be controlled by the type and amount of organosilicon compound used to form the organosilicon polymer, as well as the reaction temperature, reaction time, reaction solvent, and pH in the production of the organosilicon polymer.

The toner particles of the present invention are characterized in that inorganic oxide fine particles are thermally adhered to the surface of the core particles, and as described above, the inorganic oxide fine particles are essential for improving the adhesion between the core particles, which have a large amount of wax near the surface, and the organosilicon polymer that coats the core particles.

Inorganic oxide microparticles contain oxygen atoms with high electronegativity, and examples of such inorganic oxide microparticles include the following: silica microparticles, aluminum oxide microparticles, titanium oxide microparticles, magnesium oxide microparticles, tin oxide microparticles, zinc oxide microparticles, cerium oxide microparticles, zirconium oxide microparticles, magnesium titanate microparticles, strontium titanate microparticles, calcium titanate microparticles, strontium zirconate microparticles, calcium zirconate microparticles, and composites of these compositions. Preferred inorganic oxide microparticles are silica microparticles, titanium oxide microparticles, and strontium titanate microparticles, and more preferably strontium titanate microparticles.

The inorganic oxide fine particles preferably have a number average particle size (D1) of primary particles of 7 nm or more and 300 nm or less. More preferably, it is 7 nm or more and 55 nm or less, and even more preferably, it is 30 nm or more and 50 nm or less. When D1 is within the above range, the inorganic oxide fine particles are not completely buried in the core particles by hot air treatment, and the adhesion with the organosilicon polymer is improved, the occurrence of ghosts is suppressed, and the charging property is improved, which is preferable.

The inorganic oxide fine particles preferably have a coverage of 1% to 50% of the surface of the core particles. More preferably, it is 3% to 30%, and even more preferably, it is 10% to 20%. When the coverage is within the above range, the adhesion between the inorganic oxide fine particles and the organosilicon polymer is improved, the occurrence of ghosts is suppressed, and separation is improved. The coverage can be controlled by the amount and particle size of the inorganic oxide fine particles added, the external addition conditions, the heat treatment conditions described below, etc.

In addition, it is preferable to select and use two types of inorganic oxide fine particles from the above-mentioned fine particles in combination as the inorganic oxide fine particles to be thermally fixed to the core particle surface. By selecting and using two types of inorganic oxide fine particles from the above-mentioned fine particles, it is possible to achieve not only improved adhesion but also improved fixing separation properties and charging stability.

The inorganic oxide fine particles are preferably thermally fixed in a form embedded in a part of the surface of the core particles, and can be thermally fixed by a heat treatment device described later. As a method for thermally fixing, a method in which the inorganic oxide fine particles are mixed with the toner particles at a low temperature and then the surface is treated with hot air is preferable because it allows the inorganic oxide fine particles to be fixed uniformly. Note that when the inorganic fine particles are thermally fixed, the coverage rate of the core particle surface described above refers to the coverage rate after thermal fixing.

The state in which inorganic oxide particles are embedded in the surface of the toner particles can be confirmed by observing the surface contours of the toner particles at 80,000 times magnification using a Hitachi ultra-high resolution field emission scanning electron microscope (FE-SEM; S-4800, Hitachi High-Technologies Corporation). FE stands for Field Emission.

<Organosilicon Polymer>
A representative example of the production method for the organosilicon polymer used in the present invention is the so-called sol-gel method.

The sol-gel method uses metal alkoxide M(OR)n (M: metal, O: oxygen, R: hydrocarbon, n: metal valence) as the starting material, which undergoes hydrolysis and condensation polymerization in a solvent, passing through a sol state and then gelling. It is used to synthesize glass, ceramics, organic-inorganic hybrids, and nanocomposites. Using this manufacturing method, functional materials in various shapes, such as surfaces, fibers, bulk bodies, and fine particles, can be produced from the liquid phase at low temperatures.

Specifically, the organosilicon polymer contained in the toner particles is preferably produced by hydrolysis and condensation polymerization of a silicon compound, typically an alkoxysilane.

In addition, one of the preferred embodiments is that the surface layer containing the organosilicon polymer is uniformly provided on the surface of the toner particles. By providing the surface layer containing the organosilicon polymer uniformly on the surface of the toner particles, the adhesion to the transfer member can be reduced, and a toner can be obtained that produces good images with little graininess.

In addition, because the sol-gel process starts with a solution and forms the material by gelling the solution, it is possible to create a variety of microstructures and shapes.

The above microstructure and shape can be adjusted by the reaction temperature, reaction time, reaction solvent, pH, the type and amount of organosilicon compound added, etc.

The organosilicon polymer used in the present invention is preferably an organosilicon polymer obtained by polymerizing an organosilicon compound having a structure represented by the following formula (Z):

R ₁ represents a hydrocarbon group having 1 to 6 carbon atoms or an aryl group. The hydrocarbon group in R ₁ is a hydrocarbon group other than an aryl group. When R ₁ is a hydrocarbon group or an aryl group, it is possible to improve the hydrophobicity of the obtained organosilicon polymer, and a toner having excellent environmental stability can be obtained. When the hydrophobicity of _{R 1} is high, the charge amount tends to fluctuate greatly in various environments, so in consideration of environmental stability, R ₁ preferably has 1 to 3 carbon atoms. As the hydrocarbon group having 1 to 3 carbon atoms, a methyl group, an ethyl group, and a propyl group can be preferably exemplified, and as the aryl group, a phenyl group can be preferably exemplified. In this case, the charging property and fogging suppression are good. More preferably, R ₁ is a methyl group from the viewpoint of environmental stability and storage stability.

R ₂ to R ₄ are each independently a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group (hereinafter also referred to as "reactive group"). These reactive groups undergo hydrolysis, addition polymerization, and condensation polymerization to form a crosslinked structure, thereby obtaining a toner having excellent resistance to component contamination and development durability. The hydrolysis is mild at room temperature, and from the viewpoint of deposition and coating properties on the surface of the toner particles, a methoxy group or an ethoxy group is preferred. The hydrolysis, addition polymerization, and condensation polymerization of R ₂ to R ₄ can be controlled by the reaction temperature, reaction time, reaction solvent, and pH.

To obtain the organosilicon polymer used in this invention, it is advisable to use one or a combination of two or more organosilicon compounds having three reactive groups ( _R2 , _R3 , and _R4 ) in one molecule excluding _R1 in the formula (Z) shown above (hereinafter also referred to as "trifunctional silanes").

In addition, in the present invention, the content of the organosilicon polymer in the toner particles is preferably 0.5% by mass or more and 50% by mass or less, and more preferably 0.75% by mass or more and 40.0% by mass or less.

Examples of the above formula (Z) include the following:

Trifunctional methylsilanes such as methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxychlorosilane, methylmethoxyethoxychlorosilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydiethoxysilane, methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane, methyldiethoxyhydroxysilane, etc.

Trifunctional silanes such as ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrihydroxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, and hexyltrihydroxysilane.

Trifunctional phenylsilanes such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, and phenyltrihydroxysilane.

Trifunctional vinyl silanes such as vinyl ethoxydimethoxysilane, vinyl trichlorosilane, vinyl methoxydichlorosilane, vinyl ethoxydichlorosilane, vinyl dimethoxychlorosilane, vinyl methoxyethoxychlorosilane, vinyl diethoxychlorosilane, vinyl triacetoxysilane, vinyl diacetoxymethoxysilane, vinyl diacetoxyethoxysilane, vinyl acetoxydimethoxysilane, vinyl acetoxymethoxyethoxysilane, vinyl acetoxydiethoxysilane, vinyl trihydroxysilane, vinyl methoxydihydroxysilane, vinyl ethoxydihydroxysilane, vinyl dimethoxyhydroxysilane, vinyl ethoxymethoxyhydroxysilane, vinyl diethoxyhydroxysilane.

Trifunctional allylsilanes such as allyltrimethoxysilane, allyltriethoxysilane, allyltrichlorosilane, allyltriacetoxysilane, and allyltrihydroxysilane.

In the organosilicon polymer used in the present invention, the content of the organosilicon compound having the structure represented by formula (Z) in the organosilicon polymer is preferably 50 mol % or more, more preferably 60 mol % or more. By making the content of the organosilicon compound satisfying formula (Z) 50 mol % or more, the environmental stability of the toner can be further improved.

In addition, in the present invention, an organosilicon polymer obtained by using an organosilicon compound having a structure represented by formula (Z) in combination with an organosilicon compound having four reactive groups in one molecule (tetrafunctional silane), an organosilicon compound having three reactive groups in one molecule (trifunctional silane), an organosilicon compound having two reactive groups in one molecule (bifunctional silane), or an organosilicon compound having one reactive group (monofunctional silane) may be used to the extent that the effect of the present invention is not impaired. Examples of organosilicon compounds that may be used in combination include the following:

Dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, Aminopropyltriethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, hexamethyldisiloxane, tetraisocyanatesilane, methyltriisocyanatesilane, vinyltriisocyanatesilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane.

In the toner of the present invention, when the surface layer (surface layer, outermost layer) of the toner particles is measured using X-ray photoelectron spectroscopy (ESCA: Electron Spectroscopy for Chemical Analysis), the silicon atom concentration dSi (dSi/[dC+dO+dSi+dS]) relative to the sum (dC+dO+dSi+dS) of the carbon atom concentration dC, the oxygen atom concentration dO, the silicon atom concentration dSi, and the sulfur atom concentration dS in the surface layer of the toner particles is preferably 1.0 atomic % or more, more preferably 2.5 atomic % or more, even more preferably 5.0 atomic % or more, and particularly preferably 15.0 atomic % or more.

The ESCA is an elemental analysis of the surface layer that is several nanometers thick and extends from the surface of the toner particle to the center of the toner particle (the midpoint of the long axis). By making the concentration of silicon atoms (dSi/[dC+dO+dSi+dS]) in the surface layer of the toner particle 1.0 atomic % or more, the surface free energy of the surface layer can be reduced. As a result, contamination of the toner particle surface can be suppressed, and charging stability can be further improved.

On the other hand, the concentration of silicon atoms in the surface layer of the toner particles (dSi/[dC+dO+dSi+dS]) is preferably 33.3 atomic % or less, more preferably 28.6 atomic % or less, from the viewpoint of chargeability.

The concentration of silicon atoms in the surface layer of the toner particles can be controlled by the structure of Rf in formula (T3) above, the method of producing the toner particles when forming the organosilicon polymer, the reaction temperature, the reaction time, the reaction solvent, and the pH. It can also be controlled by the content of the organosilicon polymer. In the present invention, the surface layer of the toner particles means a layer that exists from the surface of the toner particles toward the center of the toner particles (the midpoint of the major axis) with a thickness of 0.0 nm to 5.0 nm.

<Binder resin>
The core particles in the present invention may use the following polymers as the binder resin. Homopolymers of styrene and its substitutes, such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-based copolymers, such as styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, and styrene-methacrylic acid ester copolymer; polyvinyl chloride, phenolic resin, naturally modified phenolic resin, naturally resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyethylene resin, and polypropylene resin. Among them, amorphous resins are preferred, and those containing amorphous polyester resin as the main component are more preferred from the viewpoint of low-temperature fixability. In addition, in order to fix inorganic oxide fine particles to the surface of the core particles, toners containing polyester resin as the binder resin are more preferred than toners containing styrene acrylic resin as the binder resin, because the fixation of the inorganic oxide fine particles is more likely to occur.

As the monomers used in the polyester unit of the polyester resin, polyhydric alcohols (divalent or trivalent or higher alcohols), polyvalent carboxylic acids (divalent or trivalent or higher carboxylic acids), their acid anhydrides or their lower alkyl esters are used. Here, in order to produce a branched polymer in order to express "strain hardening", it is effective to partially crosslink within the molecule of the amorphous resin, and for this purpose, it is preferable to use a polyfunctional compound having a valence of three or more. Therefore, it is preferable to include a trivalent or higher carboxylic acid, its acid anhydride or its lower alkyl ester, and/or a trivalent or higher alcohol as the raw material monomer for the polyester unit.

The following polyhydric alcohol monomers can be used as the polyhydric alcohol monomers for the polyester unit of the polyester resin:

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, hydrogenated bisphenol A, and bisphenol represented by formula (A) and its derivatives;

（式中、Ｒはエチレンまたはプロピレン基であり、ｘ及びｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙの平均値は０以上１０以下である。）

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x+y is 0 or more and 10 or less.)

Diols represented by formula (B);

Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene. Of these, glycerol, trimethylolpropane, and pentaerythritol are preferably used. These dihydric alcohols and trihydric or higher alcohols may be used alone or in combination.
As the polybasic carboxylic acid monomer used in the polyester unit of the polyester resin, the following polybasic carboxylic acid monomers can be used.

Examples of divalent carboxylic acid components include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, n-octylsuccinic acid, isooctylsuccinic acid, isooctylsuccinic acid, anhydrides of these acids, and lower alkyl esters of these acids. Of these, maleic acid, fumaric acid, terephthalic acid, and n-dodecenylsuccinic acid are preferably used.

Examples of trivalent or higher carboxylic acids, their anhydrides, or their lower alkyl esters include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra(methylenecarboxyl)methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empol trimer acid, and their anhydrides or lower alkyl esters. Among these, 1,2,4-benzenetricarboxylic acid, i.e., trimellitic acid or its derivatives, is particularly preferred because it is inexpensive and easy to control the reaction. These divalent carboxylic acids and trivalent or higher carboxylic acids can be used alone or in combination.

The method for producing the polyester unit of the present invention is not particularly limited, and known methods can be used. For example, the above-mentioned alcohol monomer and carboxylic acid monomer are charged simultaneously, and polymerized through an esterification reaction or ester exchange reaction and a condensation reaction to produce a polyester resin. The polymerization temperature is not particularly limited, but is preferably in the range of 180°C to 290°C. For example, a polymerization catalyst such as a titanium-based catalyst, a tin-based catalyst, zinc acetate, antimony trioxide, or germanium dioxide can be used when polymerizing the polyester unit.

From the viewpoint of charging stability, it is also preferable that the acid value of the polyester resin is 5 mgKOH/g or more and 30 mgKOH/g or less, and the hydroxyl value is 20 mgKOH/g or more and 70 mgKOH/g or less.

The binder resin may be a mixture of low molecular weight resin and high molecular weight resin. From the viewpoint of low temperature fixability and hot offset resistance, it is preferable that the content ratio of high molecular weight resin to low molecular weight resin is 40/60 or more and 85/15 or less by mass.

It is also preferable to include a crystalline resin in the core particles, as this further improves low-temperature fixability.

Examples of resins having crystallinity include crystalline polyester, crystalline vinyl resin, crystalline polyurethane, and crystalline polyurea. Crystalline polyester and crystalline vinyl resin are preferably used.

The crystalline polyester is obtained by polycondensation of a monomer composition containing an aliphatic diol and an aliphatic dicarboxylic acid as main components. The aliphatic diol and the aliphatic dicarboxylic acid preferably have 6 to 12 carbon atoms.

The aliphatic diol is not particularly limited, but is preferably a chain (more preferably a straight-chain) aliphatic diol, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,4-butadiene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, neopentyl glycol. Among these, particularly preferred examples are straight-chain aliphatic α,ω-diols such as ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol. Of the above alcohol components, it is preferable that 50% by mass or more, more preferably 70% by mass or more, is an alcohol selected from aliphatic diols having 6 to 12 carbon atoms.

In addition, polyhydric alcohol monomers other than the above aliphatic diols can also be used. Among the polyhydric alcohol monomers, examples of dihydric alcohol monomers include aromatic alcohols such as polyoxyethylenated bisphenol A and polyoxypropylenated bisphenol A; and 1,4-cyclohexanedimethanol. Among the polyhydric alcohol monomers, examples of trihydric or higher polyhydric alcohol monomers include aromatic alcohols such as 1,3,5-trihydroxymethylbenzene; and aliphatic alcohols such as pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, and trimethylolpropane.

Furthermore, monohydric alcohols may be used to the extent that they do not impair the properties of the crystalline polyester. Examples of such monohydric alcohols include monofunctional alcohols such as n-butanol, isobutanol, sec-butanol, n-hexanol, n-octanol, lauryl alcohol, 2-ethylhexanol, decanol, cyclohexanol, benzyl alcohol, and dodecyl alcohol.

On the other hand, the aliphatic dicarboxylic acid is not particularly limited, but is preferably a chain (more preferably a straight-chain) aliphatic dicarboxylic acid. Specific examples include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, glutaconic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, and itaconic acid, as well as the hydrolysis of the acid anhydrides or lower alkyl esters of these acids.

Of the above carboxylic acid components, preferably 50% by mass or more, more preferably 70% by mass or more, is a carboxylic acid selected from aliphatic dicarboxylic acids having 6 to 12 carbon atoms.

In addition, polycarboxylic acids other than aliphatic dicarboxylic acids can also be used. Among the other polycarboxylic acid monomers, examples of divalent carboxylic acids include aromatic carboxylic acids such as isophthalic acid and terephthalic acid; aliphatic carboxylic acids such as n-dodecyl succinic acid and n-dodecenyl succinic acid; and alicyclic carboxylic acids such as cyclohexane dicarboxylic acid, and also include their acid anhydrides or lower alkyl esters. Among the other carboxylic acid monomers, examples of trivalent or higher polycarboxylic acids include aromatic carboxylic acids such as 1,2,4-benzene tricarboxylic acid (trimellitic acid), 2,5,7-naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, and pyromellitic acid; and aliphatic carboxylic acids such as 1,2,4-butane tricarboxylic acid, 1,2,5-hexane tricarboxylic acid, and 1,3-dicarboxyl-2-methyl-2-methylene carboxypropane, and also include their acid anhydrides or lower alkyl esters.

Furthermore, the crystalline polyester may contain a monovalent carboxylic acid to the extent that the properties of the crystalline polyester are not impaired. Examples of monovalent carboxylic acids include monocarboxylic acids such as benzoic acid, naphthalene carboxylic acid, salicylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, phenoxyacetic acid, biphenyl carboxylic acid, acetic acid, propionic acid, butyric acid, octanoic acid, decanoic acid, dodecanoic acid, and stearic acid.

The crystalline polyester of the present invention can be produced according to a conventional polyester synthesis method. For example, the carboxylic acid monomer and the alcohol monomer are subjected to an esterification reaction or an ester exchange reaction, and then the desired crystalline polyester can be obtained by carrying out a polycondensation reaction according to a conventional method under reduced pressure or by introducing nitrogen gas.

The above esterification or transesterification reaction can be carried out, if necessary, using a conventional esterification catalyst or transesterification catalyst such as sulfuric acid, titanium butoxide, dibutyltin oxide, manganese acetate, or magnesium acetate.

The polycondensation reaction can be carried out using a conventional polymerization catalyst, such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide, or other known catalyst. The polymerization temperature and the amount of catalyst are not particularly limited and may be determined appropriately.

In the esterification or transesterification reaction or polycondensation reaction, all the monomers may be charged at once to increase the strength of the resulting crystalline polyester. In addition, in order to reduce the amount of low molecular weight components, a method may be used in which a divalent monomer is reacted first, and then a trivalent or higher monomer is added and reacted.

Examples of crystalline vinyl resins include resins containing polymers having units derived from polymerizable monomers that are (meth)acrylic acid esters having an alkyl group having 18 to 36 carbon atoms.

Examples of (meth)acrylic acid esters having an alkyl group having 18 to 36 carbon atoms include (meth)acrylic acid esters having a linear alkyl group having 18 to 36 carbon atoms [stearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosanyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, ceryl (meth)acrylate, octacosyl (meth)acrylate, myricyl (meth)acrylate, dodriaconta (meth)acrylate, etc.] and (meth)acrylic acid esters having a branched alkyl group having 18 to 36 carbon atoms [2-decyltetradecyl (meth)acrylate, etc.].

Among these, from the viewpoint of storage stability of the toner, preferred are (meth)acrylic acid esters having a linear alkyl group with 18 to 36 carbon atoms, more preferred are (meth)acrylic acid esters having a linear alkyl group with 18 to 30 carbon atoms, and even more preferred are linear stearyl (meth)acrylate and behenyl (meth)acrylate.

In addition, it is preferable that the ratio of units derived from a polymerizable monomer that is a (meth)acrylic acid ester having an alkyl group having 18 to 36 carbon atoms in the polymer is 10.0 mol % or more and 60.0 mol % or less relative to the total number of moles of all units in the polymer.

These crystalline resins are preferably contained in an amount of 0.5 parts by weight or more and 15 parts by weight or less per 100 parts by weight of the binder resin.

From the viewpoint of suppressing moisture adsorption, it is preferable that the acid value of the crystalline resin is 2 mgKOH/g or more and 20 mgKOH/g or less.

In addition, it is preferable to contain a wax dispersant in the core particles in order to control the state of the wax present in the core particles, as described below, and to control the state of the wax present within the range of Qi-Qh of the present invention.

As a wax dispersant, it is preferable to use a polymer in which a styrene-acrylic polymer is graft-modified to a polyolefin.

The polyolefin is not particularly limited, but examples thereof include low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, and hydrocarbon wax such as Fischer-Tropsch wax.

The polyolefin preferably has a peak temperature of 70°C or more and 100°C or less of the maximum endothermic peak measured using a differential scanning calorimeter (DSC). From the viewpoint of wax dispersibility, it is also preferable that the difference in peak temperature of the maximum endothermic peak measured using a differential scanning calorimeter (DSC) between the wax and the polyolefin is 0°C or more and 20°C or less.

Examples of monomers constituting the monomer units of the styrene-acrylic polymer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, and p-n-dodecylstyrene, as well as derivatives thereof; amino group-containing α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; acrylonitrile, meth ... vinyl monomers containing an N atom, such as acrylic acid or methacrylic acid derivatives, such as tolyl and acrylamide; unsaturated dibasic acids, such as maleic acid, citraconic acid, itaconic acid, alkenylsuccinic acid, fumaric acid, and mesaconic acid; unsaturated dibasic acid anhydrides, such as maleic anhydride, citraconic anhydride, itaconic anhydride, and alkenylsuccinic anhydride; half esters of unsaturated dibasic acids, such as methyl maleate half ester, ethyl maleate half ester, butyl maleate half ester, methyl citraconic acid half ester, ethyl citraconic acid half ester, butyl citraconic acid half ester, methyl itaconic acid half ester, methyl alkenylsuccinic acid half ester, methyl fumaric acid half ester, and methyl mesaconic acid half ester; unsaturated dibasic acid esters such as dimethyl maleic acid and dimethyl fumaric acid; α,β-unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid and cinnamic acid; α,β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic acid anhydride, anhydrides of the above α,β-unsaturated acids and lower fatty acids; vinyl monomers containing a carboxyl group such as alkenyl malonic acid, alkenyl glutaric acid, alkenyl adipic acid, anhydrides thereof, and monoesters thereof; acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate; vinyl monomers containing a hydroxyl group such as 4-(1-hydroxy-1-methylbutyl)styrene and 4-(1-hydroxy-1-methylhexyl)styrene. ; acrylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate; methacrylic acid esters such as α-methylene aliphatic monocarboxylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate.

It may also contain a vinyl monomer having a structural portion derived from a saturated alicyclic compound.

It is preferable to contain a vinyl monomer having a structural portion derived from a saturated alicyclic compound, since this further improves the charging stability. Examples of vinyl monomers having a structural portion derived from a saturated alicyclic compound include monomers such as cyclopropyl acrylate, cyclobutyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, cycloheptyl acrylate, cyclooctyl acrylate, cyclopropyl methacrylate, cyclobutyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, cyclooctyl methacrylate, dihydrocyclopentadiethyl acrylate, dicyclopentanyl acrylate, and dicyclopentanyl methacrylate, and combinations thereof.

Among these, from the viewpoint of hydrophobicity, cyclohexyl acrylate, cycloheptyl acrylate, cyclooctyl acrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, and cyclooctyl methacrylate are preferred.

In the present invention, the method for graft-modifying a styrene-acrylic polymer onto a polyolefin is not particularly limited, and any conventionally known method can be used.

In the present invention, the weight average molecular weight (Mw) of the THF-soluble portion of the polymer is preferably 5,000 or more and 70,000 or less, and more preferably 10,000 or more and 50,000 or less, as determined by gel permeation chromatography (GPC). When the weight average molecular weight (Mw) of the polymer is within the above range, the dispersibility of the wax in the toner particles is improved, and at the same time, the blocking resistance and hot offset resistance are improved.

The polymer is preferably contained in an amount of 1.0 part by mass or more and 10.0 parts by mass or less per 100 parts by mass of the binder resin.

<Wax>
Examples of waxes that can be used in the core particles of the present invention include the following: hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxides of hydrocarbon waxes such as oxidized polyethylene wax or block copolymers thereof; waxes containing fatty acid esters as the main component such as carnauba wax; and partially or completely deoxidized fatty acid esters such as deoxidized carnauba wax. Further examples include the following. Saturated straight-chain fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassidic acid, eleostearic acid, and valinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, ceryl alcohol, and melissyl alcohol; polyhydric alcohols such as sorbitol; esters of fatty acids such as palmitic acid, stearic acid, behenic acid, and montanic acid and alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, ceryl alcohol, and melissyl alcohol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene saturated fatty acid bisamides such as bisstearamide; unsaturated fatty acid amides such as ethylene bisoleamide, hexamethylene bisoleamide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacamide; aromatic bisamides such as m-xylene bisstearamide and N,N'-distearyl isophthalamide; aliphatic metal salts (commonly known as metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate; waxes obtained by grafting aliphatic hydrocarbon waxes with vinyl monomers such as styrene and acrylic acid; partial esters of fatty acids and polyhydric alcohols such as behenic acid monoglyceride; and methyl ester compounds having a hydroxyl group obtained by hydrogenating vegetable oils and fats.

Among these waxes, from the viewpoint of improving low-temperature fixability and fixation separation property, preferred are hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax, and fatty acid ester waxes such as carnauba wax. In the present invention, when a polyester resin is used as the binder resin for the core particles, hydrocarbon waxes are more preferred in that they further improve fixation separation resistance.

In the present invention, it is preferable to use wax in an amount of 2 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the binder resin.

In addition, in the endothermic curve during temperature rise measured by a differential scanning calorimetry (DSC) device, the peak temperature of the maximum endothermic peak of the wax is preferably 45°C or higher and 140°C or lower. More preferably, it is 70°C or higher and 110°C or lower, and even more preferably, it is 85°C or higher and 110°C or lower. If the peak temperature of the maximum endothermic peak of the wax is within the above range, it is preferable because it is easy to achieve both the storage stability and hot offset resistance of the toner.

<Coloring Agent>
The toner may contain a colorant. Examples of the colorant include the following.

Black colorants include carbon black, and those toned to black using a yellow colorant, a magenta colorant, and a cyan colorant. As a colorant, a pigment may be used alone, but it is more preferable to use a dye and a pigment in combination to improve the clarity in terms of the image quality of a full-color image.

Pigments for magenta toner include the following: C.I. C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57:1, 58, 60, 63, 64, 68, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; C.I. Pigment Violet 19; C.I. Bat Red 1, 2, 10, 13, 15, 23, 29, 35.

Dyes for magenta toner include the following: C.I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; C.I. Disperse Red 9; C.I. Solvent Violet 8, 13, 14, 21, 27; C.I. Disperse Violet 1; basic dyes such as C.I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; C.I. Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

Pigments for cyan toner include the following: C.I. Pigment Blue 2, 3, 15:2, 15:3, 15:4, 16, 17; C.I. Bat Blue 6; C.I. Acid Blue 45; copper phthalocyanine pigments with 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton.

An example of a dye for cyan toner is C.I. Solvent Blue 70.

Yellow toner pigments include: C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; C.I. Vat Yellow 1, 3, 20.
Yellow toner dyes include C.I. Solvent Yellow 162.

The colorant content is preferably 0.1 parts by weight or more and 30 parts by weight or less per 100 parts by weight of the binder resin.

<Charge Control Agent>
The toner may contain a charge control agent as necessary. Any known charge control agent may be used as the charge control agent contained in the toner, but a metal compound of an aromatic carboxylic acid is particularly preferred, as it is colorless, has a high charging speed, and can stably maintain a constant charge amount.

Negative charge control agents include metal salicylate compounds, metal naphthoate compounds, metal dicarboxylate compounds, polymeric compounds having sulfonic acid or carboxylic acid on the side chain, polymeric compounds having sulfonate salts or sulfonate esters on the side chain, polymeric compounds having carboxylate salts or carboxylate esters on the side chain, boron compounds, urea compounds, silicon compounds, and calixarenes. Charge control agents may be added internally or externally to the toner particles.

The amount of charge control agent added is preferably 0.2 parts by weight or more and 10 parts by weight or less per 100 parts by weight of binder resin.

<Inorganic fine particles>
The toner particles of the present invention may contain inorganic fine particles as necessary, in addition to the inorganic oxide fine particles of the present invention fixed to the surface of the core particles. The inorganic fine particles may be added internally to the toner particles or may be mixed with the toner particles as an external additive. As the external additive, inorganic fine particles (inorganic fine powder) such as silica, titanium oxide, aluminum oxide, etc. are preferable. The inorganic fine particles are preferably hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil, or a mixture thereof.

As an external additive for improving fluidity, inorganic fine particles having a specific surface area of 50 ^m2 /g or more and 400 ^m2 /g or less are preferable, and for stabilizing durability, inorganic fine particles having a specific surface area of 10 ^m2 /g or more and 50 ^m2 /g or less are preferable. In order to simultaneously improve the fluidity and stabilize the durability of the toner, inorganic fine particles having a specific surface area within the above range may be used in combination.

It is preferable that the external additive is used in an amount of 0.1 parts by weight to 10.0 parts by weight per 100 parts by weight of toner particles. A known mixer such as a Henschel mixer can be used to mix the toner particles and the external additive.

<Developer>
The toner can be used as a one-component developer, but in order to further improve dot reproducibility, it is preferable to mix the toner with a magnetic carrier and use it as a two-component developer, since this allows stable images to be obtained over a long period of time. That is, it is preferable that the toner is the toner of the present invention, which is a two-component developer containing a toner and a magnetic carrier.

As magnetic carriers, for example, iron powder with an oxidized surface, unoxidized iron powder, metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, and rare earth elements, alloy particles thereof, oxide particles, magnetic materials such as ferrite, magnetic material-dispersed resin carriers (so-called resin carriers) containing magnetic materials and a binder resin that holds the magnetic materials in a dispersed state, and other commonly known magnetic carriers can be used.

When the toner is mixed with a magnetic carrier to be used as a two-component developer, good results are usually obtained when the carrier mixing ratio is, in terms of toner concentration in the two-component developer, preferably 2% by weight to 15% by weight, more preferably 4% by weight to 13% by weight.

[Method of manufacturing toner particles]
<Production of Core Particles>
As a method for producing the core particles of the toner particles of the present invention, a pulverization method is preferred because it is easy to make the wax exist near the surface of the core particles. When a production method for producing the core particles in water, such as an emulsion aggregation method, a dissolution suspension method, or a suspension polymerization method, is used, the highly hydrophobic wax is unevenly distributed inside the core particles, and it is difficult to control the state of the wax within the range of Qi-Qh of the present invention.

Below, we explain an example of the toner manufacturing procedure using the pulverization method.

In the raw material mixing process, materials constituting the core particles, such as binder resin, wax, colorant, and other components such as charge control agents as necessary, are weighed out in predetermined amounts, blended, and mixed. Examples of mixing devices include a double-con mixer, V-type mixer, drum-type mixer, super mixer, Henschel mixer, Nauta mixer, and Mechano Hybrid (manufactured by Nippon Coke and Engineering Co., Ltd.).

Next, the mixed materials are melt-kneaded to disperse the wax in the binder resin. In the melt-kneading process, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used, and single-screw or twin-screw extruders are the mainstream due to their advantage of continuous production. Examples include a KTK twin-screw extruder (manufactured by Kobe Steel, Ltd.), a TEM twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), a PCM kneader (manufactured by Ikegai Iron Works Co., Ltd.), a twin-screw extruder (manufactured by KCK Corporation), a Co-Kneader (manufactured by Buss Co., Ltd.), and a Kneadex (manufactured by Nippon Coke and Engineering Co., Ltd.). Furthermore, the resin composition obtained by melt-kneading may be rolled with a twin roll or the like and cooled with water in a cooling process.

The cooled resin composition is then pulverized to the desired particle size in a pulverization process. In the pulverization process, the resin composition is coarsely pulverized using a pulverizer such as a crusher, hammer mill, or feather mill, and then further pulverized using a pulverizer such as a Cryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), a Super Rotor (manufactured by Nisshin Engineering Co., Ltd.), a Turbo Mill (manufactured by Turbo Kogyo Co., Ltd.), or an air jet type pulverizer.

Then, as necessary, the particles are classified using a classifier or sieve such as Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.) which uses an inertial classification method, Turboplex (manufactured by Hosokawa Micron Corporation) which uses a centrifugal classification method, TSP Separator (manufactured by Hosokawa Micron Corporation), or Faculty (manufactured by Hosokawa Micron Corporation) to obtain classified products (core particles). Among these, Faculty (manufactured by Hosokawa Micron Corporation) is preferred in terms of improving transfer efficiency, as it can simultaneously perform a spheroidizing process on the core particles during classification.

<Inorganic oxide fine particle adhesion and thermal fixation process>
A method for thermally fixing the inorganic oxide fine particles of the present invention to the surfaces of the core particles will be described below.

In the method of fixing inorganic oxide particles to the surface of the toner using hot air, inorganic oxide particles are first added to the surface of the core particles, and the inorganic oxide particles are then attached to the core particles. Examples of the method of adding inorganic oxide particles include a method in which a predetermined amount of toner particles and inorganic oxide particles are mixed together, and then stirred and mixed using a mixing device such as a double con mixer, V-type mixer, drum mixer, super mixer, Henschel mixer, Nauta mixer, Mechano Hybrid (manufactured by Nippon Coke and Engineering Co., Ltd.), or Nobilta (manufactured by Hosokawa Micron Corporation).

Then, the core particles to which the inorganic oxide microparticles are attached are heat-treated in a heat treatment process using a heat treatment device as shown in Figure 1. This heat treatment further increases the amount of wax near the surface, making it very easy to control the presence of the wax within the range of Qi-Qh and (Qi-Qh)/Qi of the present invention. As a result, the anti-wrapping property during fixing is improved.

The mixture (core particles with inorganic oxide fine particles attached) supplied by the raw material supply means 1 is introduced into the introduction pipe 3, which is installed vertically to the raw material supply means, by compressed gas adjusted by the compressed gas adjustment means 2. The mixture that passes through the introduction pipe is uniformly dispersed by the conical protruding member 4 installed in the center of the raw material supply means, and is introduced into the eight-way supply pipes 5 that radiate outward, and into the treatment chamber 6 where the heat treatment is carried out.

In FIG. 1, the mixture supplied by the raw material supply means 1 is introduced into the inlet pipe 3, which is installed on the central axis of the processing chamber 6, by compressed gas adjusted by the compressed gas adjustment means 2. The mixture that passes through the inlet pipe is uniformly dispersed by the conical protruding member 4 installed in the center of the raw material supply means, and is introduced into the eight-way supply pipe 5 that spreads radially, and is introduced into the processing chamber 6 where the heat treatment is performed from the powder particle supply port 14.

At this time, the flow of the mixture supplied to the processing chamber 6 is regulated by a regulating means 9 for regulating the flow of the mixture provided in the processing chamber 6. Therefore, the mixture supplied to the processing chamber 6 is heat-treated while swirling inside the processing chamber 6, and then cooled.

Hot air for heat-treating the supplied mixture is supplied from the hot air inlet 7 of the hot air supply means 7, and is introduced into the treatment chamber 6 by swirling the hot air in a spiral shape using a swirling member 13 for swirling the hot air. The swirling member 13 for swirling the hot air has multiple blades, and the swirling of the hot air can be controlled by the number and angle of the blades. At this time, the approximately conical distribution member 12 can reduce bias in the swirling hot air.

It is preferable that the temperature of the hot air supplied into the processing chamber 6 at the hot air outlet 11 of the hot air supplying means 7 is 100°C or higher and 300°C or lower. If the temperature at the hot air outlet 11 of the hot air supplying means 7 is within the above range, it is possible to move the wax near the surface of the core particles while preventing fusion or coalescence of the core particles due to excessive heating of the mixture, improving the anti-wrapping property. More preferably, the temperature is 20°C or higher than the peak temperature of the maximum endothermic peak of the wax.

Furthermore, the heat-treated core particles to which the inorganic oxide fine particles are thermally fixed are cooled by cold air supplied from cold air supply means 8 (8-1, 8-2, 8-3). The temperature of the cold air supplied from the cold air supply means 8 is preferably -20°C or higher and 30°C or lower. If the temperature of the cold air is within the above range, the heat-treated core particles can be efficiently cooled, and fusion or coalescence of the heat-treated core particles can be prevented without impeding the uniform spheronization treatment of the mixture. The absolute moisture content of the cold air is preferably 0.5 g/m3 or ^higher and 15.0 g/m3 ^or lower.

Next, the cooled heat-treated core particles are collected by the collection means 10 at the bottom end of the treatment chamber 6. A blower (not shown) is provided beyond the collection means 10, which transports the particles by suction.

The powder particle supply port 14 is provided so that the swirling direction of the supplied mixture and the swirling direction of the hot air are the same, and the recovery means 10 is provided on the outer periphery of the processing chamber 6 so as to maintain the swirling direction of the swirled powder particles. Furthermore, the cold air supplied from the cold air supply means 8 is configured to be supplied from the outer periphery of the device to the inner periphery of the processing chamber 6 in a horizontal and tangential direction. The swirling direction of the toner supplied from the powder particle supply port 14, the swirling direction of the cold air supplied from the cold air supply means 8, and the swirling direction of the hot air supplied from the hot air supply means 7 are all the same direction. Therefore, no turbulence occurs in the processing chamber 6, the swirling flow in the device is strengthened, a strong centrifugal force is applied to the core particles, and the dispersibility of the core particles is further improved, so that core particles with a uniform shape and few coalesced particles can be obtained.

<Organosilicon Polymer Coating Step>
The resulting core particles are then coated with the organosilicon polymer of the present invention to obtain the toner particles of the present invention.

Specific examples of how the organosilicon polymer is incorporated into the surface layer of the core particles will be described below, but the present invention is not limited to these examples.

First, the obtained core particles are dispersed in an aqueous medium. The following can be used as dispersion stabilizers for the core particles in the aqueous medium.

Inorganic dispersion stabilizers include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina.

Organic dispersion stabilizers include polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch.

In addition, known nonionic, anionic, and cationic surfactants can also be used.

Specific examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene oleyl ether, polyoxyalkylene derivatives such as polyoxyethylene alkylene alkyl ethers, sorbitan fatty acid esters such as sorbitan monolaurate and sorbitan monostearate, glycerin fatty acid esters such as glycerol monostearate, and polyoxyethylene fatty acid esters such as polyethylene glycol monolaurate.

Specific examples of anionic surfactants include alkyl sulfates such as sodium lauryl sulfate, polyoxyethylene alkyl ether sulfate salts such as sodium polyoxyethylene lauryl ether sulfate, sulfonates such as sodium dodecylbenzenesulfonate and sodium alkylnaphthalenesulfonate, and higher fatty acid salts such as sodium stearate and sodium laurate.

Specific examples of cationic surfactants include quaternary ammonium salts such as dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, lauryl trimethyl ammonium chloride, and alkyl benzyl dimethyl ammonium chloride.

Among these dispersion stabilizers, nonionic ones are preferred because they are easier to disperse.

From the viewpoint of ease of removal of the dispersion stabilizer after formation of the organosilicon polymer, it is preferable to use an inorganic dispersion stabilizer, and it is even more preferable to use a poorly water-soluble inorganic dispersion stabilizer.

In the present invention, when a poorly water-soluble inorganic dispersion stabilizer is used to disperse core particles in an aqueous medium, the amount of the dispersion stabilizer added is preferably 0.2 parts by mass or more and 2.0 parts by mass or less per 100.0 parts by mass of core particles. In addition, it is preferable to prepare the core particle dispersion medium using water in an amount of 300 parts by mass or more and 3,000 parts by mass or less per 100 parts by mass of core particles.

In the present invention, when preparing an aqueous medium in which the above-mentioned poorly water-soluble inorganic dispersant is dispersed, a commercially available dispersion stabilizer may be used as is. In addition, in order to obtain a dispersion stabilizer having a fine and uniform particle size, the poorly water-soluble inorganic dispersant may be produced in a liquid medium such as water under high-speed stirring. Specifically, when tricalcium phosphate is used as the dispersion stabilizer, a preferred dispersion stabilizer can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring to form fine particles of tricalcium phosphate. Furthermore, the use of a tricalcium phosphate dispersion stabilizer is preferable from the viewpoint of the shape stability and manufacturing stability of the coating layer of the organosilicon polymer. The reason for this is due to the crystal structure of tricalcium phosphate. Tricalcium phosphate forms a hexagonal crystal structure in which calcium ions are arranged around calcium ions. Therefore, calcium ions are more likely to be oriented in the aqueous medium on the surface of the core particles, and the electrical attraction with the silanol groups, which are the hydrolyzed parts of the organosilicon compound in the aqueous medium, is increased, making it easier to form a coating layer of the organosilicon polymer.

The pH of the condensation process can be set under any conditions, but the condensation of the organosilicon compound affects the pH of the aqueous medium. Therefore, the effects of the present invention can be further enhanced by controlling the pH of the aqueous medium.

Under acidic conditions, the hydrolysis of alkoxy groups proceeds electrophilically with protons as a catalyst, so the hydrolysis of alkoxy groups in the molecule proceeds sequentially. Therefore, silanol groups tend to remain in the condensation product of the organosilicon compound, and hydrophobization does not proceed easily. In addition, three-dimensional condensation reactions do not occur easily, and the molecular weight does not increase easily. On the other hand, under basic conditions, the hydrolysis of alkoxy groups proceeds nucleophilically with hydroxide ions as a catalyst, so the hydrolysis of alkoxy groups in the molecule proceeds simultaneously. Therefore, silanol groups tend to remain in the condensation product of the organosilicon compound, and hydrophobization proceeds easily. In addition, three-dimensional condensation reactions tend to occur easily, and the molecular weight increases easily. As a result, large organosilicon polymer particles can be formed in an aqueous medium.

As the hydrophobicity of the organosilicon polymer increases, its stability in the aqueous medium decreases and it becomes easier to migrate to the core particles. As a result, the surface of the obtained toner particles can become uneven, so it is preferable to carry out the condensation process under basic conditions. In addition, when the condensation process is carried out under basic conditions, the molecular weight of the organosilicon polymer tends to increase, making it possible to reduce the amount of organosilicon compound dissolved in the aqueous medium. This makes it possible to reduce the amount of organosilicon compound in the wastewater, which is also preferable from the viewpoint of reducing the load on the wastewater treatment process.

Specifically, the pH of the aqueous medium in the condensation step is preferably 7.5 to 12.0, more preferably 8.0 to 11.0. The pH of the condensation step can be controlled with a known acid or base.

Examples of the acid for adjusting the pH include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, boric acid, hydrofluoric acid, hydrobromic acid, permanganic acid, thiocyanic acid, phosphonic acid, phosphoric acid, diphosphoric acid, hexafluorophosphoric acid, tetrafluoroboric acid, and tripolyphosphoric acid; inorganic acids such as aspartic acid, hydrochloric acid, sulfuric acid, nitric acid, boric acid, hydrofluoric acid, hydrobromic acid, permanganic acid, thiocyanic acid, phosphonic acid, phosphoric acid, diphosphoric acid, hexafluorophosphoric acid, tetrafluoroboric acid, and tripolyphosphoric acid; and organic acids such as aspartic acid, o-aminobenzoic acid, p-aminobenzoic acid, isonicotinic acid, oxaloacetic acid, citric acid, 2-glyceric acid, glutamic acid, cyanoacetic acid, oxalic acid, trichloroacetic acid, o-nitrobenzoic acid, nitroacetic acid, picric acid, picolinic acid, pyruvic acid, fumaric acid, fluoroacetic acid, bromoacetic acid, o-bromobenzoic acid, maleic acid, and malonic acid. These acids can be used without any particular limitations. Furthermore, these acids may be used alone or in combination of two or more.

Examples of bases for adjusting the pH include alkali metals such as lithium, sodium, and potassium, and their aqueous solutions, alkali metal salts and their aqueous solutions, alkaline earth metals such as calcium and magnesium, and their aqueous solutions, alkaline earth metal salts, ammonia, and amines including urea. More specifically, examples include an aqueous solution of lithium hydroxide, an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, an aqueous solution of calcium hydroxide, an aqueous solution of magnesium hydroxide, an aqueous solution of lithium carbonate, an aqueous solution of sodium carbonate, an aqueous solution of potassium carbonate, an aqueous solution of ammonia, and urea. These bases can be used without any particular restrictions. Furthermore, these bases may be used alone or in combination of two or more.

If necessary, the surface of the toner particles may be treated with external additives such as inorganic fine particles. Methods for external treatment include blending the toner particles with a predetermined amount of various known external additives, and stirring and mixing them using a mixing device such as a double con mixer, V-type mixer, drum mixer, super mixer, Henschel mixer, Nauta mixer, Mechano Hybrid (manufactured by Nippon Coke & Engineering Co., Ltd.), or Nobilta (manufactured by Hosokawa Micron Corporation).

The methods for measuring various physical properties of toner and raw materials are explained below.

<Method for measuring Qi and Qh in core particles>
Qi and Qh in the core particles are measured under the following conditions using a DSC Q1000 (manufactured by TA Instruments).
Heating rate: 10° C./min
Measurement start temperature: 20℃
Measurement end temperature: 180°C
The melting points of indium and zinc are used to correct the temperature of the detector, and the heat of fusion of indium is used to correct the amount of heat.

Specifically, about 5 mg of a sample is precisely weighed and placed in an aluminum pan, and differential scanning calorimetry is performed, using an empty aluminum pan as a reference.
The endothermic heat amount Qi can be calculated from the integral value (J/g) of the endothermic peak derived from the wax obtained by the measurement.

If the endothermic peak derived from the wax does not overlap with the endothermic peak of other raw materials (e.g. crystalline resin), the endothermic amount of the obtained endothermic peak is treated as the endothermic amount of the maximum endothermic peak derived from the wax. If the endothermic peak of the wax overlaps with the endothermic peak of other raw materials (e.g. crystalline resin), it is necessary to subtract the endothermic amount of the other raw materials from the endothermic amount of the obtained endothermic peak.

The amount of heat absorbed from other raw materials can be determined as follows. The core particles are subjected to Soxhlet extraction with hexane solvent to dissolve the wax in the core particles in hexane. The remaining toner particles after hexane extraction are subjected to similar DSC measurement to measure the amount of heat absorbed at the endothermic peak.

Qh is determined by treating the core particles with hexane and then performing DSC measurement. 100 mg of core particles are weighed out and 30 mL of hexane is added. After shaking for 5 seconds, the mixture is filtered by suction, and the hexane-treated particles on the filter are dried under reduced pressure for 2 hours and then collected, and similarly subjected to DSC measurement. The endothermic amount of the endothermic peak derived from the wax obtained in this manner is designated as Qh (J/g).

In the case of core particles in which hot air treatment has been performed and a large amount of wax exists near the surface, like the core particles of the present invention, the surface is highly hydrophobic and the core particles are easily dispersed in hexane when hexane is added. On the other hand, core particles formed by polymerization or aggregation in an aqueous medium, or core particles formed by a pulverization method that have not been subjected to hot air treatment or that have not been subjected to sufficient hot air treatment, have extremely low wettability with hexane and may not disperse in hexane and may end up agglomerating. In such cases, the aggregated core particles are recovered by suction filtration and then Qh is determined by DSC measurement.

From the Qi and Qh thus determined, Qi-Qh and (Qi-Qh)/Qi are calculated.
For toner particles, Qi-Qh and (Qi-Qh)/Qi can be obtained in the same manner as above.

<Method of confirming the partial structure represented by formula (T3)>
The partial structure represented by formula (T3) in the organosilicon polymer contained in the toner particles is confirmed by the following method.

The presence or absence of an alkyl group, a phenyl group, or an alkylamino group represented by R in formula (T3) was confirmed by ¹³ C-NMR. The detailed structure of formula (T3) was confirmed by ¹ H-NMR, ¹³ C-NMR, and ²⁹ Si-NMR. The apparatus and measurement conditions used are shown below.

(Measurement conditions)
Equipment: AVANCE III 500 made by BRUKER
Probe: 4mm MAS BB/1H
Measurement temperature: room temperature Sample rotation speed: 6 kHz
Sample: 150 mg of a measurement sample (THF insoluble portion of toner particles for NMR measurement) was placed on a 4 mm
was placed in a sample tube.

Using this method, the presence or absence of an alkyl group, phenyl group, or alkylamino group represented by R in formula (T3) was confirmed. If a signal was confirmed, the structure of formula (T3) was deemed to be "present."

( ^13C -NMR (solid) measurement conditions)
Measured nuclear frequency: 125.77MHz
Reference substance: Glycine (external standard: 176.03ppm)
Observation width: 37.88kHz
Measurement method: CP/MAS
Contact time: 1.75 ms
Repeat time: 4s
Number of times of integration: 2048 times LB value: 50 Hz

(Method of measuring ^29Si -NMR (solid))
(Measurement conditions)
Equipment: AVANCE III 500 made by BRUKER
Probe: 4mm MAS BB/1H
Measurement temperature: room temperature Sample rotation speed: 6 kHz
Sample: 150 mg of a measurement sample (THF insoluble portion of toner particles for NMR measurement) was placed on a 4 mm
Place in a sample tube.
Measurement nuclear frequency: 99.36MHz
Reference substance: DSS (external standard: 1.534ppm)
Observation width: 29.76kHz
Measurement method: DD/MAS, CP/MAS
29Si 90° Pulse width: 4.00μs @ -1dB
Contact time: 1.75ms to 10ms
Repeat time: 30s (DD/MAS), 10s (CP/MAS)
Number of times of integration: 2048 times LB value: 50 Hz

<Method of calculating the proportion of the partial structure represented by formula (T3) (T3 structure) and the structure in which the number of O _1/2 bonded to silicon is 2.0 (SX2 structure) in the organosilicon polymer contained in the toner particles>
<Methods for confirming and quantifying T3 structure, X1 structure, X2 structure, X3 structure, and X4 structure>
The partial structures of T3, X1, X2, X3 and X4 can be confirmed by ¹ H-NMR, ¹³ C-NMR and ²⁹ Si-NMR.

After measuring the THF-insoluble portion of the toner particles by ^29Si -NMR, a plurality of silane components having different substituents and bonding groups in the toner particles are subjected to curve fitting to separate peaks into an X4 structure represented by the following general formula (X4) in which the number of O _1/2 bonded to silicon is 4.0, an X3 structure represented by the following general formula (X3) in which the number of O _1/2 bonded to silicon is 3.0, an X2 structure represented by the following formula (X2) in which the number of O _1/2 bonded to silicon is 2.0, an X1 structure represented by the following formula (X1) in which the number of O _1/2 bonded to silicon is 1.0, and a T unit structure represented by formula (T3), and the mol % of each component is calculated from the area ratio of each peak.

（式（Ｘ１）中のＲｉ、Ｒｊ、Ｒｋはケイ素に結合している有機基、ハロゲン原子、ヒドロキシ基またはアルコキシ基）

(In formula (X1), Ri, Rj, and Rk each represent an organic group, a halogen atom, a hydroxyl group, or an alkoxy group bonded to a silicon atom.)

（式（Ｘ２）中のＲｇ、Ｒｈはケイ素に結合している有機基、ハロゲン原子、ヒドロキシ基またはアルコキシ基）

(Rg and Rh in formula (X2) each represent an organic group, a halogen atom, a hydroxyl group, or an alkoxy group bonded to silicon.)

（式（Ｘ３）中のＲｆはケイ素に結合している有機基、ハロゲン原子、ヒドロキシ基またはアルコキシ基）

(Rf in formula (X3) represents an organic group bonded to silicon, a halogen atom, a hydroxyl group, or an alkoxy group).

Curve fitting is performed using EXcalibur for Windows (product name) version 4.2 (EX series), software for the JNM-EX400 manufactured by JEOL Ltd. Click on "1D Pro" from the menu icon to load the measurement data. Next, select "Curve fitting function" from "Command" on the menu bar to perform curve fitting. An example is shown in Figure 2. Peak division is performed so that the peak of the composite peak difference (a), which is the difference between the composite peak (b) and the measurement result (d), is the smallest.

Calculate the area of the X1 structure, the area of the X2 structure, the area of the X3 structure, and the area of the X4 structure, and use the following formula to calculate SX1, SX2, SX3, and SX4.

In the present invention, the silane monomer is identified by its chemical shift value, and ^the total peak area of the organosilicon polymer is determined as the sum of the areas of the X1 structure, the X2 structure, the X3 structure and the X4 structure, obtained by removing the monomer components from the total peak area in the 29Si-NMR measurement of the toner particles.
SX1+SX2+SX3+SX4=1.00
SX1={area of X1 structure/(area of X1 structure+area of X2 structure+area of X3 structure+area of X4 structure)}
SX2={area of X2 structure/(area of X1 structure+area of X2 structure+area of X3 structure+area of X4 structure)}
SX3={area of X3 structure/(area of X1 structure+area of X2 structure+area of X3 structure+area of X4 structure)}
SX4 = {area of X4 structure / (area of X1 structure + area of X2 structure + area of X3 structure + area of X4 structure)}
ST3 = {area of T3 structure/(area of X1 structure+area of X2 structure+area of X3 structure+area of X4 structure)}

The chemical shift values of silicon in the X1, X2, X3 and X4 structures are shown below.
An example of X1 structure (Ri=Rj=-OC ₂ H ₅ , Rk=-CH ₃ ): -47 ppm
An example of X2 structure (Rg=-OC ₂ H ₅ , Rh=-CH ₃ ): -56 ppm
An example of X3 structure (Rf=-CH ₃ ): -65 ppm

Furthermore, the chemical shift values of silicon in the case where the X4 structure is present are shown below.
X4 structure: -108ppm

<Method for separating organosilicon polymer contained in toner particles>
To obtain the THF-insoluble organosilicon polymer from the toner particles, the toner particles are first eluted with a strong acid, and the remaining organosilicon polymer is dried and solidified, after which THF is added to obtain the THF-insoluble fraction.

<Method for measuring concentration of silicon element present on toner particle surface>
In the present invention, the silicon element concentration (atomic %) relative to the total concentration (dC+dO+dSi) of the carbon element concentration dC, the oxygen element concentration dO, and the silicon element concentration dSi present on the toner particle surface was calculated by performing a surface composition analysis by ESCA (X-ray photoelectron spectroscopy analysis).

In the present invention, the ESCA apparatus and measurement conditions are as follows.
Equipment used: ULVAC-PHI Quantum 2000
X-ray photoelectron spectrometer measurement conditions: X-ray source Al Kα
X-ray: 100μm 25W 15kV
Raster: 300μm x 200μm
PassEnergy: 58.70eV StepSize: 0.125eV
Neutralization electron gun: 20 μA, 1 V Ar ion gun: 7 mA, 10 V
Sweep number: Si 15 times, C 10 times, O 5 times

In the present invention, the surface atomic concentration (atomic %) was calculated from the measured peak intensity of each element using the relative sensitivity factor provided by PHI.

<Method for measuring number average diameter of primary particles of inorganic fine powder>
The number average diameter of the primary particles of the inorganic fine particles is measured using a Hitachi ultra-high resolution field emission scanning electron microscope (FE-SEM) S-4800 (Hitachi High-Technologies Corporation).

Measurements are performed on the toner after inorganic fine particles have been mixed in.

The photograph is taken at a magnification of 50,000 times, and the photograph is then enlarged by a factor of two. From the resulting FE-SEM photograph, the maximum diameter (long axis diameter) a and the minimum diameter (short axis diameter) b of the inorganic microparticles are measured, and (a + b) / 2 is taken as the particle diameter of the particle. The particle diameters of 100 randomly selected inorganic microparticles are measured and the arithmetic average is calculated, which is taken as the number-average diameter of the primary particles of the inorganic micropowder.

<Method of measuring coverage of inorganic oxide fine particles>
The coverage rate of the inorganic oxide fine particles is calculated by analyzing a surface image of the toner particles taken with a Hitachi ultra-high resolution field emission scanning electron microscope (FE-SEM; S-4800, Hitachi High-Technologies Corporation) using image analysis software (Image-Pro Plus ver. 5.0, Nippon Roper Co., Ltd.).

The inorganic oxide particles present on the surface of the toner core particles are observed using the SEM device.

When making observations, it is best to choose a location where the surface of the core particle is as flat as possible.

The image in which only the inorganic oxide microparticles are extracted from the core particle surface is binarized, and the ratio of the area occupied by the inorganic oxide microparticles to the area of the core particle surface is calculated. The same operation is performed for 10 core particles, and the arithmetic mean value is calculated.

<Measurement of molecular weight of THF-soluble portion of resin>
The weight average molecular weight (Mw) of the THF-soluble portion of the resin is measured by gel permeation chromatography (GPC) as follows.

First, a sample is dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. The resulting solution is then filtered through a solvent-resistant membrane filter "Myshoridisc" (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of components soluble in THF is about 0.8 mass%. This sample solution is used to perform measurements under the following conditions.
Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: 7 columns of Shodex KF-801, 802, 803, 804, 805, 806, and 807 (manufactured by Showa Denko K.K.)
Eluent: tetrahydrofuran (THF)
Flow rate: 1.0ml/min
Oven temperature: 40.0°C
Sample injection volume: 0.10 ml

When calculating the molecular weight of the sample, a molecular weight calibration curve is used that is created using standard polystyrene resins (e.g., trade names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500" manufactured by Tosoh Corporation).

<Method of measuring softening point Tm of binder resin>
The softening point of the binder resin is measured using a constant load extrusion type capillary rheometer "Flow characteristic evaluation device Flow Tester CFT-500D" (manufactured by Shimadzu Corporation) in accordance with the manual that comes with the device. With this device, a constant load is applied from above the measurement sample by a piston, while the measurement sample filled in a cylinder is heated and melted, and the molten measurement sample is extruded from a die at the bottom of the cylinder, and a flow curve showing the relationship between the piston descent amount and temperature at this time can be obtained.

The softening point is the "melting temperature in the 1/2 method" described in the manual that comes with the "Flow characteristic evaluation device Flow Tester CFT-500D." The melting temperature in the 1/2 method is calculated as follows. First, find 1/2 of the difference between the amount of piston descent Smax at the time the outflow ends and the amount of piston descent Smin at the time the outflow starts (this is called X. X = (Smax - Smin) / 2). Then, the temperature of the flow curve when the amount of piston descent on the flow curve is X is the melting temperature in the 1/2 method.

The measurement sample is made by compressing approximately 1.0 g of resin at approximately 10 MPa for approximately 60 seconds using a tablet compression machine (e.g., NT-100H, manufactured by NPA Systems) in an environment of 25°C, and forming it into a cylindrical shape with a diameter of approximately 8 mm.

The measurement conditions for CFT-500D are as follows.
Test mode: Heating method Starting temperature: 50°C
Reached temperature: 200°C
Measurement interval: 1.0°C
Heating rate: 4.0° C./min
Piston cross-sectional area: 1.000 ^cm2
Test load (piston load): 10.0 kgf (0.9807 MPa)
Preheat time: 300 seconds Die hole diameter: 1.0 mm
Die length: 1.0 mm

<Method of measuring acid value>
The acid value is the number of milligrams of potassium hydroxide required to neutralize the acid contained in 1 g of a sample. The acid value of the polyester resin in the present invention is measured in accordance with JIS K 0070-1992, and specifically, is measured according to the following procedure.

(1) Preparation of Reagents 1.0 g of phenolphthalein was dissolved in 90 mL of ethyl alcohol (95% by volume), and ion-exchanged water was added to make up to 100 mL to obtain a phenolphthalein solution.

Dissolve 7 g of special grade potassium hydroxide in 5 mL of water, and add ethyl alcohol (95% by volume) to make 1 L. Place in an alkali-resistant container to avoid contact with carbon dioxide, etc., leave for 3 days, then filter to obtain potassium hydroxide solution. Store the resulting potassium hydroxide solution in an alkali-resistant container. The factor of the potassium hydroxide solution is determined by placing 25 mL of 0.1 mol/L hydrochloric acid in an Erlenmeyer flask, adding several drops of the phenolphthalein solution, and titrating with the potassium hydroxide solution, from the amount of potassium hydroxide solution required for neutralization. The 0.1 mol/L hydrochloric acid used is prepared in accordance with JIS K 8001-1998.

(2) Procedure (A) Main Test 2.0 g of the crushed polyester resin sample is accurately weighed into a 200 mL Erlenmeyer flask, and 100 mL of a mixed solution of toluene/ethanol (2:1) is added and dissolved over 5 hours. Then, several drops of the phenolphthalein solution are added as an indicator, and titration is performed using the potassium hydroxide solution. The end point of the titration is when the light red color of the indicator continues for about 30 seconds.
(B) Blank Test: A blank test is carried out in the same manner as above, except that no sample is used (i.e., only a mixed solution of toluene/ethanol (2:1) is used).

(3) The obtained result is substituted into the following formula to calculate the acid value.
A=[(CB)×f×5.61]/S
Here, A is the acid value (mg KOH/g), B is the amount of potassium hydroxide solution added for the blank test (mL), C is the amount of potassium hydroxide solution added for the main test (mL), f is the factor of the potassium hydroxide solution, and S is the mass of the sample (g).

<Measurement of BET specific surface area of inorganic oxide particles and external additives (inorganic fine particles)>
The BET specific surface area of the inorganic fine particles is measured in accordance with JIS Z8830 (2001). The specific measurement method is as follows.

The measurement device used is the "Automatic Specific Surface Area/Porosity Distribution Measurement Device TriStar 3000 (manufactured by Shimadzu Corporation)" which employs the gas adsorption method by the constant volume method as the measurement method. The measurement conditions are set and the measurement data is analyzed using the dedicated software "TriStar 3000 Version 4.00" that comes with this device. A vacuum pump, nitrogen gas piping, and helium gas piping are connected to this device. The value calculated by the BET multipoint method using nitrogen gas as the adsorption gas is regarded as the BET specific surface area of the inorganic microparticles in this invention.

The BET specific surface area is calculated as follows:

First, nitrogen gas is adsorbed onto the inorganic fine particles, and the equilibrium pressure P (Pa) in the sample cell and the nitrogen adsorption amount Va (mol/g) of the external additive are measured. Then, an adsorption isotherm is obtained with the relative pressure Pr, which is the value obtained by dividing the equilibrium pressure P (Pa) in the sample cell by the saturated vapor pressure Po (Pa) of nitrogen, on the horizontal axis and the nitrogen adsorption amount Va (mol/g) on the vertical axis. Next, the monolayer adsorption amount Vm (mol/g), which is the adsorption amount required to form a monolayer on the surface of the external additive, is calculated by applying the following BET formula.
Pr/Va(1-Pr)=1/(Vm×C)+(C-1)×Pr/(Vm×C)

Here, C is a BET parameter, which is a variable that varies depending on the type of measurement sample, the type of adsorbed gas, and the adsorption temperature.

The BET equation can be interpreted as a straight line with a slope of (C-1)/(Vm×C) and an intercept of 1/(Vm×C) when the X-axis is Pr and the Y-axis is Pr/Va(1-Pr). This straight line is called a BET plot.
Slope of the line = (C-1) / (Vm x C)
Line intercept = 1/(Vm x C)

If you plot the measured values of Pr and Pr/Va(1-Pr) on a graph and draw a line using the least squares method, you can calculate the slope and intercept of the line. By substituting these values into the above formula and solving the resulting simultaneous equations, you can calculate Vm and C.

Furthermore, the BET specific surface area S (m ² /g) of the inorganic fine particles is calculated from the calculated Vm and the molecular occupancy cross-sectional area of the nitrogen molecule (0.162 nm ² ) according to the following formula:
S=Vm×N×0.162× ^10-18

where N is Avogadro's number (mol ^-1 ).

Measurements using this device should be performed in accordance with the "TriStar 3000 Instruction Manual V4.0" that comes with the device, but specifically, the measurements should be performed in the following order:

Accurately weigh the mass of a tared sample cell (stem diameter 3/8 inch, volume approximately 5 ml) made of a special glass that has been thoroughly washed and dried. Then, use a funnel to add approximately 0.1 g of the additive into the sample cell.

The sample cell containing the inorganic fine particles is placed in a pretreatment device VacuPrep 061 (Shimadzu Corporation) connected to a vacuum pump and nitrogen gas piping, and vacuum degassing is continued for about 10 hours at 23°C. During vacuum degassing, the valve is adjusted to gradually degas the inorganic fine particles so that they are not sucked into the vacuum pump. The pressure in the sample cell gradually decreases with degassing, and finally reaches about 0.4 Pa (about 3 mTorr). After vacuum degassing is completed, nitrogen gas is gradually injected into the sample cell to return the sample cell to atmospheric pressure, and the sample cell is removed from the pretreatment device. The mass of this sample cell is then precisely weighed, and the exact mass of the external additive is calculated from the difference with the tare mass. During this time, the sample cell is covered with a rubber stopper during weighing to prevent the external additive in the sample cell from being contaminated by moisture in the air.

Next, a special "isothermal jacket" is attached to the stem of the sample cell containing the inorganic fine particles. A special filler rod is then inserted into the sample cell, and the sample cell is set in the analysis port of the device. The isothermal jacket is a cylindrical component with a porous inner surface and an impermeable outer surface that is capable of drawing up liquid nitrogen to a certain level by capillary action.

Next, the free space of the sample cell including the connecting device is measured. The free space is calculated by measuring the volume of the sample cell at 23°C using helium gas, then measuring the volume of the sample cell after cooling it with liquid nitrogen, also using helium gas, and converting the difference between these volumes. The saturated vapor pressure Po (Pa) of nitrogen is also measured automatically separately using a Po tube built into the device.

Next, the sample cell is evacuated and then cooled with liquid nitrogen while continuing the vacuum evacuation. Nitrogen gas is then gradually introduced into the sample cell to adsorb nitrogen molecules to the inorganic fine particles. At this time, the adsorption isotherm is obtained by measuring the equilibrium pressure P (Pa) at any time, and this adsorption isotherm is converted into a BET plot. The relative pressure Pr points for collecting data are set to 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30, for a total of six points. A straight line is drawn using the least squares method for the obtained measurement data, and Vm is calculated from the slope and intercept of the straight line. Furthermore, this Vm value is used to calculate the BET specific surface area of the inorganic fine particles as described above.

<Measurement of weight average particle size (D4) of toner particles>
The weight average particle size (D4) of the toner particles is measured using a precision particle size distribution measuring device by a pore electrical resistance method equipped with a 100 μm aperture tube, “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.), and the accompanying dedicated software for setting measurement conditions and analyzing measurement data, “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.), with an effective measurement channel count of 25,000, and the measurement data is analyzed and calculated.

The aqueous electrolyte solution used for the measurements is prepared by dissolving special grade sodium chloride in deionized water to a concentration of approximately 1% by mass, for example "ISOTON II" (manufactured by Beckman Coulter).

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

In the "Change Standard Measurement Method (SOM) screen" of the dedicated software, set the total count number in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particle 10.0 μm" (manufactured by Beckman Coulter). Press the threshold/noise level measurement button to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check the aperture tube flush after measurement.

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

Specific measurement methods are as follows (1) to (7).
(1) Pour about 200 ml of the electrolyte solution into a 250 ml round-bottom glass beaker for use with the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, remove dirt and air bubbles from inside the aperture tube using the "aperture tube flush" function of the dedicated software.
(2) Approximately 30 ml of the aqueous electrolyte solution is placed in a 100 ml flat-bottom glass beaker, and approximately 0.3 ml of a solution prepared by diluting "Contaminon N" (a 10% by weight aqueous solution of a neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, having a pH of 7, manufactured by Wako Pure Chemical Industries, Ltd.) three times by weight with deionized water is added as a dispersant.
(3) A predetermined amount of deionized water is placed in the water tank of an ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.) having two built-in oscillators with an oscillation frequency of 50 kHz and a phase shift of 180 degrees and an electrical output of 120 W, and about 2 ml of the Contaminon N is added to this water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized.
(5) In a state where the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolyte solution and dispersed. Then, ultrasonic dispersion treatment is continued for another 60 seconds. During ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted so as to be 10°C or higher and 40°C or lower.
(6) In the round-bottom beaker (1) placed in the sample stand, the electrolytic solution (5) in which the toner is dispersed is dropped using a pipette to adjust the measurement concentration to about 5%. Then, measurements are continued until the number of particles measured reaches 50,000.
(7) The measurement data is analyzed using the dedicated software that comes with the device, and the weight-average particle size (D4) is calculated. Note that when the dedicated software is set to Graph/Volume %, the "Average diameter" on the Analysis/Volume Statistics (Arithmetic Mean) screen is the weight-average particle size (D4).

The present invention will be specifically explained by the following examples. However, these are not intended to limit the present invention in any way. Unless otherwise specified, all "parts" in the following formulations are by weight.

<Production Example 1 of Strontium Titanate Microparticles>
Metatitanic acid obtained by the sulfuric acid method was deironized and bleached, then an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurized, neutralized to pH 5.8 with hydrochloric acid, filtered, and washed with water. Water was added to the washed cake to make a slurry of 1.5 mol/L in terms of _TiO2 , and hydrochloric acid was added to adjust the pH to 1.5, followed by peptization.

The desulfurized and peptized metatitanic acid was collected as _TiO2 and put into a 3L reaction vessel. A strontium chloride aqueous solution was added to the peptized metatitanic acid slurry so that the SrO/TiO2 _molar ratio was 1.15, and then the _TiO2 concentration was adjusted to 0.8 mol/L. Next, the mixture was heated to 90°C while stirring and mixing, and 444 mL of a 10 mol/L aqueous sodium hydroxide solution was added over 45 minutes while microbubbling nitrogen gas at 600 ml/min, and then stirring was performed at 95°C for 1 hour while microbubbling nitrogen gas at 400 ml/min.

The reaction slurry was then stirred while 10°C cooling water was run through the jacket of the reaction vessel to rapidly cool it to 15°C, hydrochloric acid was added until the pH reached 2.0, and stirring was continued for 1 hour. The resulting precipitate was washed by decantation, and then 5.0% by mass of sodium stearate based on the solid content was dissolved in water as an aqueous solution and added, and stirring was continued for 2 hours. After that, hydrochloric acid was added to adjust the pH to 6.5, and stirring was continued for 1 hour to precipitate stearic acid on the surface of strontium titanate.

Then, after filtering and washing, the resulting cake was left in the air at 120°C for 10 hours, and then crushed in a jet mill until no agglomerates remained, yielding strontium titanate microparticles (inorganic microparticles 1). In powder X-ray diffraction measurement, inorganic microparticles 1 showed the diffraction peak of strontium titanate.

<Production Examples 2 to 6 of Strontium Titanate Microparticles>
Strontium titanate microparticles (inorganic microparticles 2 to 6) were obtained by carrying out the same production as in Production Example 1 of strontium titanate microparticles, except that the dropwise addition time of the 10 mol/L sodium hydroxide aqueous solution was changed.

<Production Example of Silica Microparticles>
A double-tube hydrocarbon-oxygen mixed burner capable of forming an inner flame and an outer flame was used as the combustion furnace. A two-fluid nozzle for injecting slurry was installed in the center of the burner, and the silicon compound raw material was introduced. Combustible hydrocarbon-oxygen gas was injected from the periphery of the two-fluid nozzle, forming an inner flame and an outer flame that were reducing atmospheres.

The atmosphere, temperature, flame length, etc. were adjusted by controlling the amount and flow rate of the combustible gas and oxygen. Silica fine particles were formed from the silicon compound in the flame, and were then fused until the desired particle size was reached. After cooling, the particles were collected using a bag filter or the like to obtain silica fine particles. 100 parts of the obtained silica fine particles were surface-treated with 4 parts of hexamethyldisilazane to obtain silica fine particles (inorganic fine particles 7 to 10). The physical properties are shown in Table 1.

<Production Example of Titanium Oxide Fine Particles>
The titanium oxide hydrous slurry obtained by thermal hydrolysis of an aqueous solution of titanyl sulfate was neutralized to pH 7 with aqueous ammonia, filtered and washed with water to obtain a cake, and the titanium oxide in the cake was peptized with hydrochloric acid to obtain an anatase-type titania sol. The average primary particle size of this sol was 7 nm.

In addition, ilmenite ore containing 50% by mass of _TiO2 equivalent was used as a starting material, and this raw material was dried at 150°C for 2 hours, and then sulfuric acid was added to dissolve it, to obtain an aqueous solution of _TiOSO4 . This was concentrated, and 4.0 parts of the anatase type titania sol was added as a seed to 100 parts of _TiO2 equivalent, and hydrolysis was performed at 120°C to obtain a slurry of TiO(OH) ₂ containing impurities.

This slurry was repeatedly washed with water at pH 5 to 6 to thoroughly remove sulfuric acid, FeSO ₄ and impurities, thereby obtaining a slurry of high-purity metatitanic acid [TiO(OH) ₂ ].

The metatitanic acid was heat-treated at 270° C. for 6 hours and then thoroughly crushed to obtain fine particles of titanium oxide having an anatase crystal structure and a BET specific surface area of 50 m ² /g and a number-average particle size of 50 nm.

Next, 5.0% by mass of n-octyltriethoxysilane was dissolved in water and added to the anatase-type titanium oxide fine particles, and the mixture was stirred for 2 hours. Then, hydrochloric acid was added to adjust the pH to 6.5, and the mixture was stirred for 1 hour.

Then, after filtration and washing, the resulting cake was dried in air at 120°C for 10 hours and then crushed using a jet mill until no agglomerates of titanium fine particles remained, yielding titanium oxide fine particles (inorganic fine particles 11). The physical properties are shown in Table 1.

<Production Example of Binder Resin>
(Production Example 1 of Polyester Resin)
Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane:
59.0 parts (0.15 moles; 80.0 mol% based on the total number of moles of polyhydric alcohol)
Polyoxyethylene (2.2)-2,2-bis(4-hydroxyphenyl)propane:
13.6 parts (0.04 moles; 20.0 mol% based on the total number of moles of polyhydric alcohol)
Terephthalic acid: 20.8 parts (0.13 moles; 80.0 mol% based on the total number of moles of polycarboxylic acids)
Trimellitic anhydride: 6.6 parts (0.03 moles; 20.0 mol% based on the total number of moles of polycarboxylic acids)
The above materials were charged into a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. Then, 1.5 parts of tin 2-ethylhexanoate (esterification catalyst) was added as a catalyst to 100 parts of the total amount of monomers. Next, the atmosphere in the flask was replaced with nitrogen gas, and the temperature was gradually raised while stirring, and the reaction was carried out for 3 hours at a temperature of 200°C while stirring.

The pressure in the reaction vessel was then lowered to 8.3 kPa and maintained for 1 hour, after which it was cooled to 180°C and allowed to react. Once it was confirmed that the softening point, measured according to ASTM D36-86, had reached 90°C, the temperature was lowered to stop the reaction, yielding polyester resin L. The resulting polyester resin L had a softening point (Tm) of 97°C and an acid value of 7 mgKOH/g.

<Production Example 2 of Amorphous Polyester>
Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane: 73.4 parts (0.19 moles; 100.0 mol% based on the total number of moles of polyhydric alcohol)
Terephthalic acid: 11.6 parts (0.07 moles; 82.0 mol% based on the total number of moles of polycarboxylic acids)
Adipic acid: 6.8 parts (0.05 moles; 14.0 mol% based on the total number of moles of polycarboxylic acids)
The above materials were weighed and put into a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The atmosphere in the flask was then replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the reaction was carried out for 3 hours at a temperature of 200°C while stirring.

Furthermore, the pressure inside the reaction vessel was reduced to 8.3 kPa and maintained for 1 hour, after which the reaction vessel was cooled to 180° C. and returned to atmospheric pressure (first reaction step).
Trimellitic anhydride: 8.2 parts (0.04 moles; 6.0 mol% based on the total number of moles of polycarboxylic acids)
tert-Butylcatechol (polymerization inhibitor): 0.1 part The above materials were then added, the pressure in the reaction vessel was reduced to 8.3 kPa, and the reaction was carried out for 12 hours while maintaining the temperature at 145° C., and the reaction was stopped by reducing the temperature (second reaction step), thereby obtaining amorphous polyester resin H. The obtained amorphous polyester resin H had a softening point of 150° C. and an acid value of 10 mg/KOH.

(Synthesis Example of Vinyl Amorphous Resin)
50 parts of xylene was charged into an autoclave, and after replacing with nitrogen, the temperature was raised to 185°C in a sealed state with stirring. A mixed solution of 97 parts of styrene, 3 parts of n-butyl acrylate, 3 parts of di-t-butyl peroxide, and 20 parts of xylene was continuously dropped for 4 hours while controlling the temperature inside the autoclave at 170°C, and polymerization was carried out. The same temperature was maintained for another 1 hour to complete the polymerization, and the solvent was removed to obtain a vinyl-based amorphous resin. The weight average molecular weight (Mw) of the obtained resin was 5000, and the softening point (Tm) was 108°C.

<Production Example of Wax Dispersant>
Low molecular weight polypropylene (melting point 80°C):
15.0 parts (0.03 moles; 3.0 mol% based on the total moles of constituent monomers)
Xylene: 25.0 parts The above materials were weighed and placed in a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The atmosphere in the flask was replaced with nitrogen gas, and the temperature was gradually increased to 175° C. while stirring.
·styrene:
64.5 parts (0.62 moles; 76.0 mol% based on the total number of moles of constituent monomers)
Cyclohexyl methacrylate:
9.6 parts (0.06 moles; 7.0 mol% based on the total moles of constituent monomers)
・Butyl acrylate:
11.5 parts (0.09 moles; 11.0 mol% based on the total number of moles of constituent monomers)
Methyl methacrylate:
2.4 parts (0.02 moles; 3.0 mol% based on the total moles of constituent monomers)
・Xylene: 10.0 parts ・Di-t-butylperoxyhexahydroterephthalate: 0.5 parts The above materials were then dropped over 2.5 hours and stirred for another 40 minutes. The solvent was then distilled off to obtain a vinyl resin in which a styrene-acrylic polymer was grafted onto polypropylene. The obtained vinyl resin had a peak molecular weight Mp of 7000 and a softening point of 120°C.

<Production Example of Crystalline Polyester>
1,6-Hexanediol: 34.5 parts (0.29 moles; 100.0 mol% based on the total number of moles of polyhydric alcohols)
Dodecanedioic acid: 65.5 parts (0.28 moles; 100.0 mol% based on the total number of moles of polycarboxylic acids)
The above materials were weighed into a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. After replacing the atmosphere in the flask with nitrogen gas, the temperature was gradually raised with stirring, and the reaction was carried out for 2.5 hours at 140°C with stirring.

Next, the pressure in the reaction vessel was reduced to 8.3 kPa, and the reaction was continued for 4 hours while maintaining the temperature at 200°C.

Then, the pressure in the reaction vessel was reduced to 5 kPa or less, and the reaction was carried out at 200°C for 3 hours to obtain a crystalline polyester. The melting point of the obtained crystalline polyester was 70°C.

<Production Example 1 of Core Particles>
Polyester resin L 75 parts Polyester resin H 25 parts Crystalline polyester 3 parts Wax dispersant 3 parts Hydrocarbon wax 7 parts (Fischer-Tropsch wax; peak temperature of maximum endothermic peak 90° C.)
・C.I. Pigment Blue 15:3 5 parts The above materials were mixed using a Henschel mixer (FM-75 type, manufactured by Nippon Coke & Engineering Co., Ltd.) at a rotation speed of 20 s ^-1 and a rotation time of 5 min, and then kneaded at a discharge temperature of 120 ° C. using a twin-screw kneader (PCM-30 type, manufactured by Ikegai Co., Ltd.) set at a temperature of 110 ° C. The kneaded product obtained was cooled and coarsely crushed to 1 mm or less using a hammer mill to obtain a coarsely crushed product. The obtained coarsely crushed product was finely crushed using a mechanical crusher (T-250, manufactured by Freund Turbo Co., Ltd.). Furthermore, classification was performed using Faculty F-300 (manufactured by Hosokawa Micron Co., Ltd.) under the operating conditions of a classification rotor rotation speed of 130 s ^-1 and a dispersion rotor rotation speed of 120 s ^-1 , and core particles 1 were obtained.

<Production Example 2 of Core Particles>
Core particles 2 were obtained in the same manner as in Core Particle Production Example 1, except that polyester resin L and polyester resin H were not used and were replaced with 100 parts of an amorphous vinyl resin.

<Production Example 3 of Core Particles>
Core particles 3 were obtained in the same manner as in Core Particle Production Example 1, except that the hydrocarbon wax in Core Particle Production Example 1 was replaced with 5 parts of ester wax (carnauba wax; peak temperature of maximum endothermic peak: 85° C.).

<Core Particle Production Examples 4 to 11>
Core particles 4 to 11 were obtained by carrying out the same production process as in Core Particle Production Example 1, except that the parts of the hydrocarbon wax and/or the parts of the wax dispersant in Core Particle Production Example 1 were replaced with those shown in Table 2. The physical properties are shown in Table 2.

<Production Example 1 of Core Particles Having Inorganic Oxide Fine Particles Adhered to Their Surfaces Before Heat Treatment>
The obtained core particles 1 and inorganic oxide fine particles were blended in predetermined amounts and mixed in a Henschel mixer FM-10C type (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.) at a rotation speed of 30 s ^-1 and a rotation time of 10 min to obtain pre-heat-treated core particles 1. At this time, the inorganic oxide fine particles were blended with 100 parts of the core particles. The parts of the inorganic oxide fine particles added are shown in Table 3.

<Production Examples 2 to 32 of Core Particles Having Inorganic Oxide Fine Particles Adhered to Their Surfaces Before Heat Treatment>
Pre-heat-treated core particles 2 to 32 were produced in the same manner as in Pre-heat-treated core particles having inorganic oxide fine particles attached to their surfaces, except that in Pre-heat-treated core particles 1 having inorganic oxide fine particles attached to their surfaces, the types and parts of inorganic oxide fine particles were replaced with those shown in Table 3. The physical properties are shown in Table 3.

<Production Example 1 of Heat-Treated Core Particles Having Inorganic Oxide Fine Particles Thermally Adhered to Their Surfaces>
Next, the pre-heat-treated core particles 1 were heat-treated using the surface treatment device shown in Fig. 1 to obtain heat-treated core particles 1 having inorganic oxide fine particles thermally fixed to the surface. The operating conditions were as follows: feed rate = 2 kg/hr, hot air temperature = 160°C, hot air flow rate = 6 ^m3 /min, cold air temperature = -5°C, cold air flow rate = 4 ^m3 /min, blower air flow rate = 20 ^m3 /min, injection air flow rate = 1 ^m3 /min.

<Production Examples 2 to 38 of Heat-Treated Core Particles Having Inorganic Oxide Fine Particles Thermally Adhered to the Surface>
Heat-treated core particles having inorganic oxide fine particles thermally fixed to their surfaces were produced in the same manner as in Production Example 1 of core particles having inorganic oxide fine particles thermally fixed thereto, except that the core particles before heat treatment and the hot air temperature were changed to those shown in Table 4, and heat-treated core particles 2 to 38 having inorganic oxide fine particles thermally fixed thereto were obtained.

<Production Example of Aqueous Dispersion Stabilizer Solution 1>
The above materials were put into a reaction vessel equipped with a reflux condenser and a thermometer. The reaction vessel was then kept at 60° C. while stirring at 12,000 rpm using a high _- speed stirring device _TK -Homomixer.
CaCl ₂ aqueous solution (1.0 mol/liter) 85.0 parts The above materials were gradually added thereto to obtain a dispersion stabilizer aqueous solution 1 containing a fine poorly water-soluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ .

<Production Example of Silane Compound Hydrolyzed Solution 1>
The above materials were placed in a reaction vessel equipped with a stirrer, the pH was adjusted to 3.0 with 10% by mass hydrochloric acid, and hydrolysis was carried out with stirring to obtain a silane compound hydrolyzed liquid 1. Completion of hydrolysis was confirmed when the liquid, which was initially separated into two phases, became a single phase.

<Production Examples of Silane Compound Hydrolyzed Solutions 2 to 5>
The reaction was carried out in the same manner as in the production example of silane compound hydrolyzed solution 1, except that the silane compounds were changed to those shown in Table 5, to obtain silane compound hydrolyzed solutions 2 to 5.

<Production Example of Surfactant Aqueous Solution 1>
Polyoxyethylene styrenated phenyl ether 10.0 parts Ion-exchanged water 90.0 parts The above materials were placed in a reaction vessel equipped with a stirrer and dissolved with stirring to obtain surfactant aqueous solution 1.

<Toner Production Example 1>
(Dispersion process in aqueous medium)
The above materials were placed in a reaction vessel equipped with a thermometer. The reaction vessel was heated to 25° C., and the mixture was dispersed at 5,000 rpm with a homogenizer (Ultra Turrax T50, manufactured by IKA Japan Co., Ltd.) for 6 minutes to obtain a heat-treated core particle dispersion liquid 1.

(Condensation step)
Heat-treated core particle dispersion 1 100.0 parts Silane compound hydrolysis solution 1 1.8 parts The above materials were put into a reaction vessel equipped with a stirrer and a thermometer. The reaction vessel was heated to 70° C. while stirring at 200 rpm. The pH was adjusted to 9.0 with 1 mol/L NaOH aqueous solution, and the mixture was stirred for 240 minutes to carry out a condensation reaction. The pH was then adjusted to 1.5 with dilute hydrochloric acid to remove the dispersion stabilizer. After that, the mixture was filtered using Kiriyama filter paper (No. 5C: pore size 1 μm) to separate the particles and the filtrate. The obtained particles were further washed with ion-exchanged water and vacuum-dried at 30° C. for 24 hours to obtain toner particles 1 coated with an organosilicon polymer.

Furthermore, 0.5 parts of hydrophobic silica fine particles having a BET specific surface area of 100 ^m2 /g and surface-treated with 5% by mass of polydimethylsiloxane were added to the obtained toner particles 1 (99.5 parts) coated with the organosilicon polymer, and mixed in a Henschel mixer (FM-75, manufactured by Nippon Coke and Engineering Co., Ltd.) at a rotation speed of 30 s ^-1 for a rotation time of 10 minutes to obtain toner 1 containing toner particles 1. The physical properties are shown in Table 6.

<Toner Production Examples 2 to 43>
Toners 2 to 43 were obtained by carrying out the same procedure as in Toner Production Example 1, except that the heat-treated core particles, inorganic oxide fine particles, and silane compound hydrolyzate were changed to those shown in Table 6.

<Production Example of Magnetic Core Particle 1>
Step 1 (weighing and mixing step):
The ferrite raw materials were weighed so as to obtain the above composition ratio _, and then crushed and _mixed for 5 hours in a dry vibration mill _using stainless steel _beads with a diameter _of 1/8 inch.

Step 2 (pre-firing step):
The obtained pulverized material was made into pellets of about 1 mm square using a roller compactor. The pellets were passed through a vibrating sieve with 3 mm openings to remove coarse powder, and then through a vibrating sieve with 0.5 mm openings to remove fine powder. The pellets were then fired in a burner-type firing furnace at 1000° C. for 4 hours in a nitrogen atmosphere (oxygen concentration 0.01% by volume) to produce calcined ferrite. The composition of the resulting calcined ferrite was as follows:
(MnO) _a (MgO)b(SrO)c( _Fe2O3 )d
In the above formula, a = 0.257, b = 0.117, c = 0.007, d = 0.393

Step 3 (grinding step):
After crushing to about 0.3 mm with a crusher, 30 parts of water was added to 100 parts of the calcined ferrite and crushed in a wet ball mill using zirconia beads with a diameter of 1/8 inch for 1 hour. The slurry was crushed in a wet ball mill using alumina beads with a diameter of 1/16 inch for 4 hours to obtain a ferrite slurry (finely crushed calcined ferrite).

・Process 4 (granulation process):
To the ferrite slurry, 1.0 part of ammonium polycarboxylate as a dispersant and 2.0 parts of polyvinyl alcohol as a binder were added per 100 parts of calcined ferrite, and the mixture was dried in a spray dryer (manufacturer: Okawara Kakoki) to form spherical particles. The resulting particles were adjusted in particle size and then heated at 650° C. for 2 hours in a rotary kiln to remove the organic components of the dispersant and binder.

Step 5 (firing step):
In order to control the firing atmosphere, the material was heated from room temperature to 1300° C. in a nitrogen atmosphere (oxygen concentration 1.00% by volume) in an electric furnace over a period of 2 hours, and then fired at a temperature of 1150° C. for 4 hours. The material was then cooled to 60° C. over a period of 4 hours, returned from the nitrogen atmosphere to the air, and taken out at a temperature of 40° C. or less.

Step 6 (sorting step):
After crushing the agglomerated particles, low magnetic particles were removed by magnetic separation, and coarse particles were removed by sieving through a sieve with 250 μm openings to obtain magnetic core particles 1 having a volume distribution-based 50% particle size (D50) of 37.0 μm.

<Preparation of Coating Resin 1>
Cyclohexyl methacrylate monomer 26.8% by mass
Methyl methacrylate monomer 0.2% by weight
Methyl methacrylate macromonomer 8.4% by mass
(Macromonomer having a weight average molecular weight of 5000 and a methacryloyl group at one end)
Toluene 31.3% by mass
Methyl ethyl ketone 31.3% by mass
Azobisisobutyronitrile 2.0% by mass
Among the above materials, cyclohexyl methacrylate, methyl methacrylate, methyl methacrylate macromonomer, toluene, and methyl ethyl ketone were added to a four-necked separable flask equipped with a reflux condenser, a thermometer, a nitrogen inlet tube, and a stirrer, and nitrogen gas was introduced to create a sufficient nitrogen atmosphere, and then the mixture was heated to 80°C, azobisisobutyronitrile was added, and the mixture was refluxed for 5 hours to polymerize. Hexane was poured into the resulting reaction product to precipitate a copolymer, and the precipitate was filtered and then vacuum dried to obtain a coating resin 1. 30 parts of the resulting coating resin 1 were dissolved in 40 parts of toluene and 30 parts of methyl ethyl ketone to obtain a polymer solution 1 (solid content 30% by mass).

<Preparation of Coating Resin Solution 1>
Polymer solution 1 (resin solid content concentration 30%) 33.3% by mass
Toluene 66.4% by mass
Carbon black (Regal 330; manufactured by Cabot Corporation) 0.3% by mass
(Primary particle size 25 nm, nitrogen adsorption specific surface area 94 m ² /g, DBP oil absorption 75 ml/100 g)
These were dispersed for 1 hour using a paint shaker with zirconia beads having a diameter of 0.5 mm. The resulting dispersion was filtered through a 5.0 μm membrane filter to obtain a coating resin solution 1.

<Production Example of Magnetic Carrier 1>
(Resin coating process):
The coating resin solution 1 was added to a vacuum degassing kneader maintained at room temperature so that the resin component was 2.5 parts per 100 parts of the filled core particles 1. After addition, the mixture was stirred at a rotation speed of 30 rpm for 15 minutes, and after a certain amount of the solvent (80 mass%) had evaporated, the mixture was heated to 80°C while mixing under reduced pressure, and toluene was distilled off over 2 hours, after which it was cooled. The obtained magnetic carrier was separated into low magnetic products by magnetic separation, passed through a sieve with an opening of 70 μm, and then classified with a wind classifier to obtain a magnetic carrier 1 having a 50% particle size (D50) of 38.2 μm based on the volume distribution.

<Production Example 1 of Two-Component Developer>
Toner 1 (8.0 parts) was added to magnetic carrier 1 (92.0 parts), and mixed in a V-type mixer (V-20, manufactured by Seishin Enterprises) to obtain two-component developer 1.

<Production Examples of Two-Component Developers 2 to 43>
Two-component developers 2 to 43 were obtained by carrying out the same production process as in the production example of two-component developer 1, except that the toner was changed as shown in Table 7.

Example 1
[evaluation]
[1. Evaluation of low-temperature fixability]
The image forming apparatus was a modified Yanon full-color copier imageRUNNER ADVANCE C5560, and the above-mentioned two-component developer 1 was placed in the cyan developer and/or magenta developer of the image forming apparatus, and the evaluation described below was performed. The modifications were made so that the fixing temperature, process speed, DC voltage VDC of the developer carrier, charging voltage VD of the electrostatic latent image carrier, and laser power could be freely set.

The images were prepared under normal temperature and humidity (NN) conditions (temperature 23°C, relative humidity 50% to 60%) with the toner amount on the paper adjusted to 1.0 mg/ ^cm2 , and an unfixed image was prepared so that the image had a horizontal band with an image printing ratio of 25% on the trailing edge side in the paper feed direction. Copy paper GF-C300 (A4, basis weight 300.0 g/ ^m2 , sold by Canon Marketing Japan Inc.) was used as the evaluation paper.

After that, in a low temperature and low humidity (LL) environment (temperature 15°C, relative humidity 15% or less), the process speed was set to 450 mm/sec, and the fixing temperature was increased in increments of 5°C from 120°C, and the lowest temperature at which no offset occurred was defined as the low-temperature fixing temperature. The evaluation results are shown in Table 8.

(Evaluation Criteria for Low Fixing Temperature)
A: Less than 150°C (good)
B: 150°C or higher and lower than 160°C (good)
C: 160° C. or higher and lower than 170° C. (This is the level at which the effects of the present invention are obtained).
D: 170° C. or higher (a level at which the effects of the present invention are not fully obtained).

[2. Evaluation of Anti-Wrapping Property]
The two-component developer 1 was tested in the fixing temperature range using the evaluation machine used in the low-temperature fixing property evaluation. Images were printed in monochrome mode in a normal temperature and normal humidity (NN) environment (temperature 23° C., relative humidity 50% to 60%), with the toner amount on the paper adjusted to 1.0 mg/ ^cm2 , and an unfixed image with a margin of 2 mm from the leading edge in the paper feed direction and an image print ratio of 25% was created. Copy paper CS-680 (A4, basis weight 68.0 g/ ^m2 , sold by Canon Marketing Japan Inc.) was used for evaluation.

After that, in a high temperature and high humidity (HH) environment (temperature 30°C, relative humidity 80%), the process speed was set to 300 mm/sec, and the fixing temperature was increased in increments of 5°C from 140°C, and the upper limit temperature at which the fixing paper did not wrap around was determined as the anti-wrapping temperature.

The resistance to adhesion was ranked according to the following criteria. The evaluation results are shown in Table 8.

(Evaluation Criteria for Anti-Fixing Wrapping Property)
A: 175℃ or higher (very good)
B: 165°C or higher and lower than 175°C (good).
C: 155°C or higher and lower than 165°C (This is the level at which the effects of the present invention are obtained.)
D: Less than 155° C. (This is a level at which the effects of the present invention are not sufficiently obtained.)

[3. Evaluation of charging stability]
The image forming apparatus was a modified Yanon full-color copier imageRUNNER ADVANCE C5560, and the above-mentioned two-component developer 1 was placed in a cyan developer of the image forming apparatus, and a cyan toner bottle was filled with toner 1 to perform the evaluation described below. The modification was that the mechanism for discharging the excess magnetic carrier from the developer was removed.

The amount of toner laid on the paper in the FFh image (solid image) was adjusted to 0.45 mg/ ^cm2 . FFh is a value obtained by expressing 256 gradations in hexadecimal, with 00h being the first gradation (white background) of the 256 gradations and FF being the 256th gradation (solid area) of the 256 gradations.

In the durability image output test, a durability image output test of 10,000 sheets was performed with an image ratio of 5%. The test was performed in a high temperature and high humidity (HH) environment (temperature 30°C, relative humidity 80%). During the continuous printing of 10,000 sheets, the sheets were printed under the same development and transfer conditions (without calibration) as the first sheet.

The evaluation paper used was copy paper GF-C081 (A4, basis weight 81.4 g/m ² , sold by Canon Marketing Japan Inc.).

The items and evaluation criteria for image output evaluation at the initial stage (first sheet) and after 10,000 sheets of continuous paper feed are shown below. The evaluation results are shown in Table 8.

(Measurement of Image Density)
Using an X-Rite color reflection densitometer (500 series: manufactured by X-Rite), the image densities of the FFh image area and the solid area at the initial (first sheet) and 10,000th sheets were measured, and the difference Δ between the two image densities was used to rank them according to the following criteria. The evaluation results are shown in Table 8.
A: Less than 0.04 (very good).
B: 0.04 or more and less than 0.09 (good)
C: 0.09 or more and less than 0.15 (this is the level at which the effects of the present invention are obtained).
D: 0.15 or more (a level at which the effects of the present invention are not fully obtained)

[4. Evaluation of external additive ghosting]
The image forming apparatus was a modified Yanon full-color copier imageRUNNER ADVANCE C5560, and the above-mentioned two-component developer 1 was placed in a cyan developer of the image forming apparatus, and a cyan toner bottle was filled with toner 1 to perform the evaluation described below. The modification was that the mechanism for discharging the excess magnetic carrier from the developer was removed.

The amount of toner laid on the paper in the FFh image (solid image) was adjusted to 0.45 mg/ ^cm2 . FFh is a value obtained by expressing 256 gradations in hexadecimal, with 00h being the first gradation (white background) of the 256 gradations and FF being the 256th gradation (solid area) of the 256 gradations.

The test was performed in a normal temperature and low humidity (NL) environment (temperature 23°C, relative humidity 5%).

The evaluation paper used was copy paper GF-C081 (A4, basis weight 81.4 g/m ² , sold by Canon Marketing Japan Inc.).

First, 100 sheets of an image with vertical bands parallel to the paper feed direction and white areas other than the vertical bands were printed at an image ratio of 10%. The vertical bands were FFh images (solid images). During successive sheets, the sheets were fed under the same development and transfer conditions (without calibration) as the first sheet.

After 100 sheets were printed, a full-page halftone image (80h) was printed and used to evaluate the initial ghosting of external additives.

After that, an image with vertical bands parallel to the paper feed direction and white areas other than the vertical bands was printed on 10,000 more sheets at an image ratio of 10%. During the continuous paper feed, the same development and transfer conditions (without calibration) were used as for the first sheet.

After 10,000 sheets were printed, a full-page halftone image (80h) was printed and used to evaluate the ghosting of external additives after durability testing.

Using an X-Rite color reflection densitometer (500 series: manufactured by X-Rite), the image densities of the vertical bands and the white background were measured in the halftone image (80h) 8 at the beginning (after 100 sheets were passed) and after durability test (after 10,000 sheets were passed), and the additive ghost property was evaluated from the difference Δ between the two image densities and ranked according to the following criteria. The evaluation results are shown in Table 8.
A: Less than 0.03 (very good).
B: 0.03 or more and less than 0.06 (good)
C: 0.06 or more and less than 0.11 (this is the level at which the effects of the present invention are obtained).
D: 0.11 or more (a level at which the effects of the present invention are not fully obtained)

5. Evaluation of Transfer Uniformity
The image forming apparatus was a modified Yanon full-color copier imageRUNNER ADVANCE C5560, and the above-mentioned two-component developer 1 was placed in a cyan developer of the image forming apparatus, and a cyan toner bottle was filled with toner 1 to perform the evaluation described below. The modification was that the mechanism for discharging the excess magnetic carrier from the developer was removed.

The amount of toner laid on the paper in the FFh image (solid image) was adjusted to 0.45 mg/ ^cm2 . FFh is a value obtained by expressing 256 gradations in hexadecimal, with 00h being the first gradation (white background) of the 256 gradations and FF being the 256th gradation (solid area) of the 256 gradations.

In the durability image output test, a durability image output test of 10,000 sheets was performed at an image ratio of 0.6%. The test was performed in a normal temperature and low humidity (NL) environment (temperature 23°C, relative humidity 5%). During the continuous passing of 10,000 sheets, the sheets were passed under the same development and transfer conditions (no calibration) as the first sheet. The evaluation paper used was recycled copy paper GF-R100W (A4, basis weight 67.0 g/ ^m2 , sold by Canon Marketing Japan Inc.).

The items and evaluation criteria for image output evaluation at the initial stage (first sheet) and after 10,000 sheets of continuous paper feed are shown below. The evaluation results are shown in Table 8.

(Evaluation of Image Uniformity)
After the durability test of 10,000 sheets, a solid image was output, a 2 cm square image was captured by a digital microscope, and the captured image was converted to 8-bit grayscale using Image-J. The density histogram was then measured and its standard deviation was calculated. The standard deviation was ranked according to the following evaluation criteria.
A: Standard deviation less than 2.0 (very good, no unevenness can be seen with the naked eye)
B: Standard deviation of 2.0 or more and less than 4.0 (very good)
C: Standard deviation is 4.0 or more and less than 6.0 (the effect of the present invention is obtained)
D: Standard deviation of 6.0 or more (the effect of the present invention is not obtained, and non-uniformity is felt from a distance)

[Examples 2 to 39, Comparative Examples 1 to 4]
The evaluation was carried out in the same manner as in Example 1, except that the two-component developer 1 was changed to two-component developers 2 to 43. The evaluation results are shown in Table 8.

1. Raw material fixed amount supply means, 2. Compressed gas flow rate adjustment means, 3. Inlet pipe, 4. Projection-shaped member, 5. Supply pipe, 6. Treatment chamber, 7. Hot air supply means, 8 (8-1, 8-2, 8-3). Cold air supply means, 9. Regulating means, 10. Recovery means, 11. Hot air supply means outlet, 12. Distribution member, 13. Swirling member, 14. Powder particle supply port

Claims (9)

1. A method for producing a toner having toner particles having core particles containing a binder resin and a wax, and inorganic oxide fine particles on the surface of the core particles, and a coating layer containing an organosilicon polymer coating the core particles, comprising the steps of:
The core particles satisfy the following relationship, where the endothermic heat of the endothermic peak derived from the wax measured by differential scanning calorimetry (DSC) is Qi (J/g) and the endothermic heat of the endothermic peak derived from the wax measured by DSC after the core particles are treated with hexane is Qh (J/g):
0.7≦Qi−Qh≦20.0
The organosilicon polymer has a partial structure represented by the following formula (T3):
In a ^29Si -NMR measurement of the tetrahydrofuran insoluble matter of the toner particles, the ratio [ST3] of the peak area of the partial structure represented by the following formula (T3) to the total peak area of the organosilicon polymer satisfies the relationship ST3≧0.05,
R-Si(O _1/2 ) ₃ (T3)
(In formula (T3), R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.)
the inorganic oxide fine particles are thermally fixed to the surface of the core particles,
a step of adhering the inorganic oxide fine particles to the surface of the core particles containing the binder resin and the wax;
and dispersing the core particles having the inorganic oxide fine particles attached thereto in an aqueous medium.
a step of coating the surface of the core particles to which the inorganic oxide fine particles are attached with the organosilicon polymer,
a step of treating the core particles having the inorganic oxide fine particles adhered thereto with hot air after the step of adhering the inorganic oxide fine particles to the surfaces of the core particles ; 2. The method for producing a toner according to claim 1, wherein the value of Qi-Qh is 1.0 or more and 7.0 or less. The organosilicon polymer has, when measured using X-ray photoelectron spectroscopy,
3. The method for producing a toner according to claim 1, wherein the concentration of silicon atoms (dSi/[dSi+dO+dC]) relative to the sum (dSi+dO+dC) of the concentration of silicon atoms dSi, the concentration of oxygen atoms dO, and the concentration of carbon atoms dC in the surface layer of the core particle is 2.5 atomic % or more. 4. The method for producing a toner according to claim 1, wherein the core particles satisfy the relationship: 0.15≦(Qi−Qh)/Qi≦0.90. 5. The method for producing a toner according to claim 1, wherein the coverage of the inorganic oxide fine particles with respect to the surface of the core particles is 3% or more and 30% or less. 6. The method for producing a toner according to claim 1, wherein the inorganic oxide fine particles have a number average particle size of primary particles of 7 nm or more and 55 nm or less. 7. The method for producing a toner according to claim 1, wherein the inorganic oxide fine particles are strontium titanate fine particles. The method for producing a toner according to any one of claims 1 to 7, wherein the binder resin contains a polyester resin. 9. The method for producing a toner according to claim 1, wherein the wax is a hydrocarbon wax.

Images