Toner

Abstract

To provide a toner having charge rising property in a high-temperature and high-humidity environment and charge stability in a low-temperature and low-humidity environment and giving excellent image quality even when the toner contains hydrotalcite particles and silica fine particles.SOLUTION: A toner includes toner particles containing a binder resin, and inorganic fine particles, in which the inorganic fine particles contain strontium titanate fine particles A, silica fine particles B, and hydrotalcite particles C, Si is present on surfaces of the strontium titanate fine particles A, and a value of a mass ratio of Si to Sr (Si / Sr) detected in fluorescent X-ray analysis of the strontium titanate fine particles A satisfies the following formula (1): 0.20 ≤ Si / Sr ≤ 0.60 (1) SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to toners used in copying machines and printers that use electrophotography or electrostatic recording methods. [Background technology]

[0002] 2. Description of the Related Art In recent years, image forming apparatuses such as copiers and printers have been used for a variety of purposes and in a variety of environments, and are therefore required to be able to achieve stable image quality in any environment. In order to achieve stable image quality, for example, Patent Document 1 discloses that the charging property of the toner is improved by disposing an external additive having both positive and negative polarity, such as hydrotalcite particles (hereinafter also referred to as "hydrotalcite"), on the surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-194837 Summary of the Invention [Problem to be solved by the invention]

[0004] The hydrotalcite particles are charged with the opposite polarity to the toner, and easily act as a carrier, improving the toner's chargeability. By combining hydrotalcite with a material that imparts high fluidity to the toner, such as silica fine particles, it is possible to provide a toner with excellent charge buildup even in environments where chargeability tends to decrease, such as high-temperature, high-humidity environments, and to achieve stable image quality. To enhance the function of hydrotalcite as a carrier, the hydrotalcite needs to be in a state with a high degree of freedom on the toner surface. However, if the hydrotalcite is arranged with a high degree of freedom, the hydrotalcite often becomes concentrated, especially during long-term use. Furthermore, when hydrotalcite is used in combination with silica fine particles, the highly adhesive silica fine particles adhere to the hydrotalcite surface, making it easier for agglomerates of hydrotalcite to form via the silica fine particles, resulting in significant concentration of the hydrotalcite.

[0005] In particular, when hydrotalcite concentrates in an environment where electrostatic charge tends to increase, such as a low-temperature, low-humidity environment, the electrostatic charge becomes excessive, causing various image problems such as ghosting at the end of a long-term use period. Increasing the adhesion of hydrotalcite to the toner particle surface is considered to prevent this phenomenon, but this reduces the function of hydrotalcite as a carrier, thereby reducing the benefits of using hydrotalcite. Furthermore, when hydrotalcite and silica fine particles are used together, problems such as component contamination caused by the above-mentioned agglomerates are likely to occur. As described above, in a system using hydrotalcite particles and silica fine particles, a toner that can provide stable image quality in all environments has not yet been realized.

[0006] Therefore, the present disclosure provides a toner that contains hydrotalcite particles and silica fine particles, and that has charge rise properties in a high-temperature, high-humidity environment and charge stability in a low-temperature, low-humidity environment, and that can provide excellent image quality. [Means for solving the problem]

[0007] The present disclosure provides a toner containing toner particles containing a binder resin and inorganic fine particles, The inorganic fine particles are strontium titanate fine particles A, silica fine particles B, and hydrotalcite fine particles B. Contains site particle C, Si is present on the surface of the strontium titanate microparticles A, The toner has a mass ratio of Si to Sr (Si / Sr) detected by fluorescent X-ray analysis of the strontium titanate fine particles A, which satisfies the following formula (1): 0.20≦Si / Sr≦0.60 (1) [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a toner that contains hydrotalcite particles and silica fine particles, and that has charge rise properties in a high-temperature, high-humidity environment and charge stability in a low-temperature, low-humidity environment, and that can provide excellent image quality. [Brief explanation of the drawings]

[0009] [Figure 1] Figure 1 shows the images used for ghost evaluation. [Figure 2] 2A and 2B are schematic diagrams of a powder resistivity measurement device. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ. Note that when XX is a group, multiple XXs may be selected, and the same applies to YY and ZZ. In this disclosure, the term "monomer unit" refers to the reacted form of a monomer substance in a polymer. For example, in an amorphous polyester resin, one unit is defined as a unit between ester bonds. In addition, in the calculation of mole percent, one unit corresponds to one molecule. The origin of a monomer unit from a certain monomer substance can be confirmed by the fact that the structure of the monomer unit corresponds to the structure of the reacted monomer substance.

[0011] As mentioned above, in systems that use both hydrotalcite particles and silica fine particles, the hydrotalcite tends to concentrate, causing the problem of overcharging in low-temperature, low-humidity environments. One method for suppressing excessive charging is to incorporate a low-resistivity material such as strontium titanate fine particles into the toner. However, ordinary strontium titanate fine particles tend to be charged with the opposite polarity to silica fine particles, resulting in electrostatic attraction between the two. This promotes the formation of hydrotalcite agglomerates via the silica fine particles, making it impossible to improve the concentration of the hydrotalcite. As a result of extensive research, the present inventors have found that incorporating Si into the surface of strontium titanate microparticles and controlling the ratio of Si to Sr is effective in preventing the generation of agglomerates and improving the concentration of hydrotalcite.

[0012] That is, the present disclosure provides a toner containing toner particles containing a binder resin and inorganic fine particles, The inorganic fine particles contain strontium titanate fine particles A, silica fine particles B, and hydrotalcite particles C, Si is present on the surface of the strontium titanate microparticles A, The toner has a mass ratio of Si to Sr (Si / Sr) detected by fluorescent X-ray analysis of the strontium titanate fine particles A, which satisfies the following formula (1): 0.20≦Si / Sr≦0.60 (1)

[0013] The reason why the above configuration is effective will be explained. By incorporating Si into the surface of strontium titanate microparticles in a range that satisfies the above formula (1), the triboelectric series becomes closer to that of silica microparticles while maintaining low resistance. Therefore, the strontium titanate microparticles are more likely to be charged with the same polarity as the silica microparticles, and are electrostatically repelled by the silica microparticles, suppressing the formation of hydrotalcite agglomerates via the silica microparticles. As a result, the concentration of hydrotalcite is improved, and the effect of hydrotalcite in improving charge buildup in high-temperature, high-humidity environments can be fully achieved. Furthermore, combined with the effect of strontium titanate microparticles as a low-resistivity material, overcharging in low-temperature, low-humidity environments is suppressed. Furthermore, the problem of component contamination caused by agglomerates is also improved. Therefore, it is possible to obtain a toner that has charge rise property in a high-temperature, high-humidity environment and charge stability in a low-temperature, low-humidity environment, and that can provide excellent image quality.

[0014] The toner will be described in more detail below. The toner of the present disclosure contains toner particles containing a binder resin and inorganic fine particles. The inorganic fine particles contain strontium titanate fine particles A, and Si is present on the surface of the strontium titanate fine particles A. The method for confirming the presence of Si on the surface of the strontium titanate fine particles A will be described in detail below, but this can be confirmed by SEM-EDS measurement. If Si is not present on the surface of the strontium titanate fine particles A, the effects of the present disclosure cannot be obtained.

[0015] Furthermore, the mass ratio of Si to Sr (Si / Sr) detected by fluorescent X-ray analysis of the strontium titanate microparticles A satisfies the following formula (1). 0.20≦Si / Sr≦0.60 (1) When (Si / Sr) is 0.20 or more, the electrostatic repulsion between the silica fine particles and the strontium titanate fine particles A is sufficient, and the concentration of hydrotalcite can be suppressed. On the other hand, when (Si / Sr) is 0.60 or less, the resistance of the strontium titanate fine particles A is maintained at an appropriate level.

[0016] The toner also contains fine silica particles B and fine hydrotalcite particles C. The above-mentioned effects can only be achieved when the toner contains all of the strontium titanate fine particles A, the fine silica particles B, and the hydrotalcite particles C.

[0017] A preferred configuration of the present disclosure will be described below. Strontium titanate fine particle A content M A is, for example, 0.05 to 2.5 parts by mass, preferably 0.1 to 1.5 parts by mass, more preferably 0.3 to 1.5 parts by mass, and even more preferably 0.5 to 1.5 parts by mass, relative to 100 parts by mass of toner particles. When the content is 0.1 part by mass or more, the overcharge suppression effect is sufficiently large, and when it is 1.5 parts by mass or less, the chargeability of the toner is sufficiently large. Note that the strontium titanate microparticles of the present disclosure are microparticles containing Si present on their surfaces.

[0018] The number-average particle diameter of the strontium titanate fine particles A is, for example, 10 to 120 nm, and preferably 25 to 80 nm. When the number-average particle diameter is 25 nm or more, overcharging is less likely to occur and the charge distribution tends to be sharper. Furthermore, when the number-average particle diameter is 80 nm or less, the toner charge buildup is faster.

[0019] The content of the silica fine particles B is preferably 0.1 to 1.5 parts by mass, more preferably 0.4 to 1.4 parts by mass, and even more preferably 0.4 to 1.0 part by mass, relative to 100 parts by mass of the toner particles. If the content is within the above range, the fluidity and charge rise property of the toner will be better.

[0020] The number average particle diameter of the silica fine particles B is, for example, 5 to 80 nm, preferably 5 to 50 nm, and more preferably 6 to 30 nm. If the particle diameter is within the above range, the fluidity and charge rise property of the toner will be better.

[0021] Content M of hydrotalcite particles C Cis, for example, 0.04 to 1.20 parts by mass, and preferably 0.05 to 1.00 parts by mass, relative to 100 parts by mass of toner particles. If the content is within the above range, the charge rise property and charge stability of the toner and the scratch resistance of the fixed image become better.

[0022] The number average particle diameter of the hydrotalcite particles C is, for example, 30 to 700 nm, and preferably 60 to 500 nm. If the particle diameter is within the above range, the charge rise property and charge stability of the toner will be better.

[0023] Powder resistivity R of strontium titanate fine particle A A For example, 7.0 x 10 7 ~7.0×10 12 Ω cm, 1.0×10 8 ~1.0×10 12 Ω·cm is preferred, and 1.0×10 9 ~1.0×10 12 It is more preferable that the resistance is Ω·cm. A is 1.0×10 8 When the resistance is Ω·cm or more, the charging property becomes better, and R A is 1.0×10 12 If the resistivity is Ω·cm or less, the effect of suppressing excessive charging is more sufficient. Powder resistivity R of strontium titanate fine particle A A can be controlled by the particle size of the strontium titanate microparticles, the amount of Si added such as the silica-containing particle source during production, and the type and content of the surface treatment agent.

[0024] The powder resistivity of strontium titanate fine particle A is R A When R A It is preferable that the mass ratio (Si / Sr) satisfies the following formula (4): A / (Si / Sr) is more preferably 1.0×10 9 ~2.0×10 11 is. 1.7×10 8 ≦R A / (Si / Sr)≦3.0×10 12···(4) By satisfying the above formula (4), the charge rise property and charge stability become better.

[0025] The content of strontium titanate fine particles A relative to 100 parts by mass of toner particles is M A The content of hydrotalcite particles C relative to 100 parts by mass of toner particles is M C Then, M C M against A The ratio value M A / M C is, for example, 0.20 to 25.0. A / M C It is preferable that satisfies the following formula (2). 0.30≦M A / M C ≦20.0 (2) By satisfying the above formula (2), the charge rise property and charge stability become better.

[0026] It is preferable that the mass ratio of Si to Sr (Si / Sr) detected by fluorescent X-ray analysis of the strontium titanate microparticles A satisfies the following formula (3). 0.26≦Si / Sr≦0.50 (3) By satisfying the above formula (3), the charge rise property and charge stability become particularly good. The Si / Sr ratio can be controlled by the amount of Si added, such as in the silica-containing particle source, during the production of strontium titanate microparticles, and the type and content of the surface treatment agent containing Si.

[0027] It is preferable that Si-containing protrusions are present on the surface of the strontium titanate microparticles A. The presence of Si-containing protrusions on the surface of the strontium titanate microparticles A facilitates the electrostatic repulsion effect with the silica microparticles, reduces the adhesiveness of the strontium titanate microparticles themselves, and enhances the effect of inhibiting the formation of agglomerates of hydrotalcite.

[0028] The convex portions are preferably formed by silica fine particles. Examples of the convex portions include convex portions formed by buried silica fine particles and convex portions formed by fixed silica fine particles. The same effect is exhibited by both the convex portions formed by buried silica fine particles and the convex portions formed by fixed silica fine particles without being buried. The silica fine particles that form the convex portions are, for example, silica fine particles other than silica fine particles B.

[0029] The Si-containing convex portions can be formed by adding a silica-containing particle source when producing strontium titanate microparticles A. This will be described in detail later. From the viewpoint of charge build-up properties, the number-average particle diameter of the particles in the convex portions is preferably less than 5 nm. The number-average particle diameter of the particles in the convex portions is preferably 1 nm or more and less than 5 nm.

[0030] The Bragg angle of strontium titanate microparticles A is defined as Θ. In this case, in a CuKα X-ray diffraction spectrum obtained with 2Θ in the range of 10° to 90°, it is preferable that the microparticles have peaks in the ranges of 39.700°±0.150° and 46.200°±0.150°. When the area of ​​the peak at 39.700°±0.150° is defined as Sa and the area of ​​the peak at 46.200°±0.150° is defined as Sb, the ratio Sb / Sa is preferably 1.80 to 2.30, and more preferably 1.90 to 2.10.

[0031] Strontium titanate with peaks at these positions has a perovskite structure belonging to the cubic crystal system, and the peaks in the ranges of 39.700°±0.150° and 46.200°±0.150° are diffraction peaks derived from lattice planes with Miller indices (111) and (200), respectively. Generally, particles belonging to the cubic crystal system tend to have a hexahedral shape, and strontium titanate microparticles also grow during the manufacturing process while retaining the (100) and (200) planes that correspond to the plane directions of the hexahedron. When using strontium titanate microparticles that have an appropriate ratio of the (200) plane, which corresponds to the plane direction of the hexahedron, and the (111) plane, which corresponds to the vertex direction, component contamination can be further suppressed.

[0032] The toner particles preferably contain an ester wax. The inclusion of the ester wax improves low-temperature fixability and the abrasion resistance of the fixed image. The mechanism by which the abrasion resistance is improved is thought to be as follows.

[0033] The hydrotalcite present on the surface of the fixed image has a relatively large particle size, so it is easily detached when the surface of the fixed image is rubbed. When the toner particles contain an ester wax, the ester groups of the ester wax and the hydroxyl groups on the surface of the hydrotalcite form hydrogen bonds, preventing the hydrotalcite from detaching from the surface of the fixed image. As a result, abrasion resistance is improved.

[0034] The ester wax is preferably a polyfunctional ester wax having two or more ester groups, which improves compatibility with the binder resin and further improves low-temperature fixability.

[0035] The ester wax is preferably a bifunctional ester wax having two ester groups. Having two ester groups provides an optimal balance between the aforementioned effect of inhibiting the release of hydrotalcite and the increased frictional force that accompanies the increased water adsorption due to the presence of multiple ester groups, further improving abrasion resistance.

[0036] Each component constituting the toner and the method for producing the toner will be described in more detail below. <Strontium titanate fine particles A> The strontium titanate fine particles A can be produced, for example, by a normal pressure heating reaction method. In this case, a mineral acid peptized product of a hydrolyzed titanium compound and a strontium titanate fine particle A are used as titanium oxide sources. A water-soluble acidic strontium source compound may be used as the strontium source. The method for forming Si-containing protrusions on the surface of strontium titanate microparticles involves mixing a mineral acid peptized product of a titanium compound hydrolysate, a strontium source, and a silica-containing particle source, and then reacting the mixture of raw materials at 60 to 100°C while adding an aqueous alkaline solution, followed by acid treatment.

[0037] The atmospheric pressure heating reaction method will be explained below. The titanium oxide source is a mineral acid peptized product of a hydrolyzed titanium compound, preferably metatitanic acid obtained by a sulfuric acid method and having an SO content of 1.0 mass % or less, more preferably 0.5 mass % or less, which is peptized with hydrochloric acid to a pH of 0.8 to 1.5.

[0038] On the other hand, as a strontium source, strontium nitrate or hydrochloride can be used. The nitrate may be, for example, strontium nitrate. The hydrochloride may be, for example, strontium chloride. The strontium titanate microparticles obtained here have a perovskite crystal structure, which is preferable in that the environmental stability of charging is further improved.

[0039] Next, shape control will be explained. One example of a method for obtaining the shape of the strontium titanate fine particles is to carry out a dry mechanical treatment. For example, Hybridizer (manufactured by Nara Machinery Works), Nobilta (manufactured by Hosokawa Micron Corporation), Mechanofusion (manufactured by Hosokawa Micron Corporation), and Hyflex Gral (manufactured by EarthTechnica Co., Ltd.) can be used. By treating strontium titanate microparticles with these devices, it is easy to control the Sb / Sa ratio to between 1.80 and 2.30.

[0040] When the shape of strontium titanate microparticles is controlled by mechanical treatment, fine powder of the strontium titanate microparticles may be generated. In order to remove the fine powder, it is preferable to perform acid treatment after the mechanical treatment. In the acid treatment, it is preferable to adjust the pH to 0.1 or more and 5.0 or less using hydrochloric acid. In addition to hydrochloric acid, nitric acid, acetic acid, etc. can be used for the acid treatment. It is preferable to perform mechanical treatment to control the shape of the strontium titanate microparticles before performing surface treatment on the strontium titanate microparticles.

[0041] Examples of silica-containing particle sources include sodium silicate, silica, etc. Addition of a silica-containing particle source can form Si-containing convex portions. The amount of silica-containing particle source added is a factor that affects the Si-containing protrusions present on the surface of strontium titanate microparticles, and can be adjusted appropriately to obtain the desired particle size and shape.

[0042] As the alkaline aqueous solution, a caustic alkali can be used, but among these, an aqueous sodium hydroxide solution is preferred.

[0043] In this production method, factors that affect the particle size of the resulting strontium titanate microparticles and the Si-containing protrusions present on the surfaces of the strontium titanate microparticles include the following. These include the pH when metatitanic acid is peptized with hydrochloric acid, the mixing ratio of the titanium oxide source, the strontium source, and the silica-containing particle source, the concentration of the titanium oxide source at the start of the reaction, the concentration of the silica-containing particle source, the temperature when the alkaline aqueous solution is added, the addition rate, the reaction time, and the stirring conditions.

[0044] In addition, in the step of adding the alkaline aqueous solution, the half-value width of the strontium titanate microparticles can be controlled by adding the alkaline aqueous solution while applying ultrasonic vibration. By applying ultrasonic vibration, the crystal precipitation rate increases, and particles with a small crystallite size can be obtained. In order to control the half-value width, it is preferable to rapidly cool the aqueous solution after the reaction by adding an alkaline aqueous solution.

[0045] Examples of methods for rapid cooling include adding pure water cooled to 10° C. or below until the temperature reaches the desired level. Rapid cooling can prevent the crystallite size from increasing during the cooling process. Furthermore, if the reaction is stopped by suddenly lowering the temperature of the system, for example by immersing the system in ice water, after the addition of the alkaline aqueous solution, the reaction can be forcibly stopped before the crystal growth reaches saturation, and the particle size distribution can be controlled.

[0046] Furthermore, the particle size distribution can also be controlled by making the reaction system non-uniform by reducing the stirring speed, changing the stirring method, etc. These factors can be adjusted as appropriate to obtain strontium titanate microparticles and Si-containing convex portions with the desired particle size and particle size distribution. In order to prevent the formation of carbonates during the reaction process, it is preferable to prevent contamination with carbon dioxide gas by, for example, carrying out the reaction under a nitrogen gas atmosphere.

[0047] The mixing ratio of the titanium oxide source and the strontium source during the reaction, where strontium is represented by Sr and its oxide is represented by SrO, is preferably SrO / TiO2 molar ratio of 0.90 or more and 1.40 or less, more preferably 1.05 or more and 1.20 or less.

[0048] When the SrO / TiO2 (molar ratio) is 1.00 or less, the reaction product tends to contain not only metal titanate but also unreacted titanium oxide. Because strontium has a relatively high solubility in water, while the titanium oxide source has a relatively low solubility in water, when the SrO / TiO2 (molar ratio) is 1.00 or less, the reaction product tends to contain not only metal titanate but also unreacted titanium oxide.

[0049] The concentration of the titanium oxide source at the beginning of the reaction is preferably 0.050 mol / L or more and 1.300 mol / L or less, and more preferably 0.080 mol / L or more and 1.200 mol / L or less, in terms of TiO2. By increasing the concentration of the titanium oxide source at the beginning of the reaction, the number average particle size of the primary particles of the strontium titanate microparticles can be reduced.

[0050] When adding the aqueous alkaline solution, if the temperature is 100°C or higher, a pressure vessel such as an autoclave will be required, and practically, the temperature is preferably in the range of 60°C to 100°C.

[0051] Furthermore, the slower the addition rate of the alkaline aqueous solution, the larger the particle size of strontium titanate microparticles and the Si-containing convex portions that are obtained, whereas the faster the addition rate, the smaller the particle size of strontium titanate microparticles and the Si-containing convex portions that are obtained. The rate of addition of the aqueous alkaline solution is preferably 0.001 to 1.2 equivalents / h, more preferably 0.002 to 1.1 equivalents / h, relative to the charged raw material. These rates can be adjusted appropriately depending on the particle size to be obtained.

[0052] In this production method, it is preferable to further acid-treat the strontium titanate microparticles obtained by the atmospheric pressure heating reaction. When producing strontium titanate microparticles by the atmospheric pressure heating reaction, if the mixing ratio of the titanium oxide source to the strontium source, SrO / TiO2 (molar ratio), exceeds 1.00, the unreacted strontium remaining after the reaction may react with carbon dioxide in the air to produce impurities such as carbonates. To facilitate uniform coating with the surface treatment agent, it is recommended to add an alkaline aqueous solution and then perform an acid treatment to remove the unreacted metal source.

[0053] In the acid treatment, the pH is preferably adjusted to 2.5 or more and 7.0 or less, more preferably 4.5 or more and 6.0 or less, using hydrochloric acid. As the acid, in addition to hydrochloric acid, nitric acid, acetic acid, etc. can be used for the acid treatment. When sulfuric acid is used, metal sulfates that have low solubility in water are likely to be generated.

[0054] The shape of the strontium titanate microparticles may be controlled. The strontium titanate microparticles are preferably cubic or rectangular. Furthermore, a dry mechanical treatment may be used as a method for controlling the shape of the strontium titanate microparticles.

[0055] The strontium titanate microparticles may be surface-treated. The surface treatment agent is not particularly limited, but examples thereof include disilylamine compounds, halogenated silane compounds, silicone compounds, and silane coupling agents. The ratio (Si / Sr) can be controlled by the surface treatment agent.

[0056] The disilylamine compound is a compound having a disilylamine (Si-N-Si) moiety. Examples of the disilylamine compound include hexamethyldisilazane (HMDS), N-methyl-hexamethyldisilazane, and hexamethyl-N-propyldisilazane. Examples of the halogenated silane compound include dimethyldichlorosilane.

[0057] Examples of silicone compounds include silicone oils and silicone resins (varnishes). Examples of silicone oils include dimethyl silicone oils, methylphenyl silicone oils, α-methylstyrene-modified silicone oils, chlorophenyl silicone oils, and fluorine-modified silicone oils. Examples of silicone resins (varnishes) include methyl silicone varnishes and phenylmethyl silicone varnishes.

[0058] Examples of the silane coupling agent include a silane coupling agent having an alkyl group and an alkoxy group, a silane coupling agent having an amino group and an alkoxy group, and a fluorine-containing silane coupling agent.

[0059] More specific examples of the silane coupling agent include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylmethoxysilane, trimethyldiethoxysilane, triethylmethoxysilane, triethyldiethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, isobutyltrimethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyldimethoxymethylsilane, γ-aminopropyldiethoxymethylsilane, 3,3,3-trifluoropropyldimethoxysilane, 3,3,3-trifluoropropyldiethoxysilane, perfluorooctylethyltriethoxysilane, and 1,1.1-trifluorohexyldiethoxysilane.

[0060] The silane coupling agent is preferably a silane coupling agent having an alkyl group and an alkoxy group, such as dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylmethoxysilane, trimethyldiethoxysilane, triethylmethoxysilane, triethyldiethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, isobutyltrimethoxysilane, octyltrimethoxysilane, or octyltriethoxysilane.

[0061] Among the above silane coupling agents, those with alkyl groups having 4 or less carbon atoms have good electrostatic properties. It is preferable from the viewpoint of the silane-containing resin, and it is more preferable that it is treated with isobutyltrimethoxysilane. The amount of the treatment agent is preferably 0.5 to 25.0 parts by mass per 100 parts by mass of the strontium titanate microparticles. The above-mentioned surface treatment agents may be used alone or in combination of two or more.

[0062] The C content (carbon content) derived from the hydrophobic treatment agent in the strontium titanate fine particles A is, for example, 0.5 to 10.0 mass %, and preferably 0.8 to 5.0 mass %. When the C content is within the above range, the charge buildup and charge stability are improved.

[0063] <Silica fine particles B> The silica fine particles B may be, for example, the following: silica such as wet-process silica or dry-process silica, or treated silica obtained by surface-treating these with a silane compound or silicone oil. The silica fine particles B are more preferably treated silica fine particles that have been hydrophobized with silicone oil having a dimethylsiloxane structure.

[0064] The SP value of silicone oil with a dimethylsiloxane structure is D (J / cm 3 ) 1 / 2 The SP value of the surface treatment agent of the above-mentioned strontium titanate fine particles A is SP A (J / cm 3 ) 1 / 2 When SP A -SP D The absolute value of SP is preferably 3.50 or less. A -SP D When the absolute value of is 3.50 or less, the polarities of the strontium titanate fine particles A and the silica fine particles B become close to each other, and the electrostatic repulsion effect becomes more likely to work, which is preferable. However, the SP value of the silicone oil having a dimethylsiloxane structure refers to the SP value of the dimethylsiloxane structure, and the SP value of the surface treatment agent of strontium titanate microparticles A refers to the SP value of the form after the surface treatment agent has reacted with the strontium titanate microparticles. The method for calculating the SP value will be described later.

[0065] Silica fine particle B has a specific surface area of ​​30m2 measured by nitrogen adsorption using the BET method. 2 / g or more 300m 2 / g or less is preferred.

[0066] <Hydrotalcite Particles C> The hydrotalcite particles C may be, for example, general hydrotalcite particles represented by the following structural formula (A). M 2+ y M 3+ x (OH)2A n- (x / n) mH2O (A) where 0 <x≦0.5、y=1-x、m≧0である。

[0067] M 2+ , and M 3+ represent divalent and trivalent metals, respectively. M 2+ is preferably at least one divalent metal ion selected from the group consisting of Mg, Zn, Ca, Ba, Ni, Sr, Cu, and Fe. 3+ is preferably at least one trivalent metal ion selected from the group consisting of Al, B, Ga, Fe, Co, and In.

[0068] A n- is an n-valent anion, CO3 2- , O.H. - , Cl - , I - , F - , Br - , SO4 2- , HCO3 - , CH3COO - , and NO3 - These may be present alone or in combination. Hydrotalcite particles C are M 3+ It is preferable that at least Al is contained as M. 2+ It is preferable that the particulate hydrotalcite C contains at least Mg as the sintered body. It is more preferable that the particulate hydrotalcite C contains Al and Mg. The hydrotalcite particles may be a solid solution containing a plurality of different elements, and may also contain a trace amount of a monovalent metal.

[0069] <Other external additives> Specific examples of other external additives include inorganic fine particles such as titanium oxide, and resin fine particles such as vinyl resin, polyester resin, silicone resin, etc. These external additives are preferably added by applying shear force in a dry state, for example.

[0070] <Binder resin> The toner particles contain a binder resin, and the content of the binder resin is preferably 50% by mass or more of the total amount of resin components in the toner particles.

[0071] The binder resin is not particularly limited, but examples thereof include styrene-acrylic resin, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, mixed resins or composite resins thereof. The binder resin preferably contains at least one selected from the group consisting of styrene-acrylic resin and polyester resin. The binder resin more preferably contains styrene-acrylic resin.

[0072] Examples of the styrene-acrylic resin include homopolymers made of the following polymerizable monomers, copolymers obtained by combining two or more of these, and mixtures thereof. Styrenic monomers such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene and p-phenylstyrene; (meth)acrylic monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-amyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, dimethyl phosphate ethyl (meth)acrylate, diethyl phosphate ethyl (meth)acrylate, dibutyl phosphate ethyl (meth)acrylate, and 2-benzoyloxyethyl (meth)acrylate, (meth)acrylonitrile, 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid, and maleic acid; Vinyl ether monomers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketone monomers such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; Polyolefins such as ethylene, propylene, and butadiene.

[0073] The styrene-acrylic resin may contain a polyfunctional polymerizable monomer, if necessary. Examples of the polyfunctional polymerizable monomer include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2'-bis(4-((meth)acryloxydiethoxy)phenyl)propane, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.

[0074] It is preferable that the toner particles have polyester resin D on the surface in terms of environmental stability.

[0075] The polyester resin D preferably has, as a monomer unit constituting a polymer chain, at least one selected from the group consisting of a monomer unit derived from an alcohol having an alicyclic structure and a monomer unit derived from a carboxylic acid having an alicyclic structure. The "monomer unit" refers to the reacted form of a monomer substance in a polymer. Polyester resin D is, for example, a polycondensate of an acid component and an alcohol component. A polymer chain is formed by the polycondensation. The polymer chain contains a structure in which a monomer unit obtained from the acid component and a monomer unit obtained from the alcohol component are bonded by an ester bond. For example, these monomer units form a repeating unit. In polyester resin D, it is preferable that at least one of the monomer unit obtained from the acid component and the monomer unit obtained from the alcohol component has an alicyclic structure.

[0076] This alicyclic structure is incorporated into the polymer chain as a monomer unit itself, which is a structural unit of the polymer chain, i.e., the alicyclic structure is linked to a directly adjacent monomer unit, and is not located in a group bonded to the polymer chain, for example, a side group or pendant group that does not have a repeating unit structure as a polymer.

[0077] The polyester resin D may have only a linear main chain as the polymer chain, or may have a branched chain having a main chain and side chains. In the case of a branched chain, an alicyclic structure may be incorporated as a structural unit of the main chain and / or side chain. The weight average molecular weight (Mw) of the polyester resin D is, for example, 5,000 to 50,000, and preferably 8,000 to 20,000.

[0078] An alicyclic compound refers to a compound containing a non-aromatic cyclic structure. In terms of classification based on the constituent elements, alicyclic structures include alicyclic hydrocarbon structures in which the non-aromatic cyclic structure is composed only of carbon and hydrogen, and alicyclic heterocyclic structures in which the non-aromatic cyclic structure contains carbon, hydrogen, and other elements. Either of these alicyclic structures can be used.

[0079] Examples of the monomer as the acid component (acid monomer) and the monomer as the alcohol component (alcohol monomer) containing an alicyclic hydrocarbon structure include the following various monomers.

[0080] Examples of the acid monomer include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, cis-1-cyclohexene-1,2-dicarboxylic acid, norbornanedicarboxylic acid, norbornenedicarboxylic acid, 1,3-adamantanedicarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid, and methylcyclohexenetricarboxylic acid.

[0081] Examples of alcohol monomers include 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, 1,4-cyclohexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 4-(2-hydroxyethyl)cyclohexanol, 4-(hydroxymethyl)cyclohexanol, 4,4'-bicyclohexanol, 1,3-adamantanediol, etc. Examples of monomers having an alicyclic heterocyclic structure include alcohol monomers such as isosorbide and spiroglycol.

[0082] In particular, by using isosorbide as the alcohol monomer, it is possible to obtain a polyester resin It is more preferable that the main chain and / or side chain of the polyester resin D has an isosorbide structure as a structural unit of the polymer chain. By having an isosorbide structure, the toner surface layer becomes highly polar, and electrostatic attraction with the hydrotalcite becomes moderately easy. As a result, concentration of the hydrotalcite can be suppressed. In other words, it is preferable that the polyester resin D has a monomer unit derived from isosorbide.

[0083] The (corresponding) monomer unit derived from isosorbide is represented by the following formula (H): [ka]

[0084] In addition to alcohols or carboxylic acids having an alicyclic structure, polyester resin D can be prepared by a method of dehydration condensation of the following: dibasic acids or their derivatives (carboxylic acid halides, esters, acid anhydrides) with dihydric alcohols, and, if necessary, trifunctional or higher functional polybasic acids or their derivatives (carboxylic acid halides, esters, acid anhydrides), monobasic acids, trifunctional or higher functional alcohols, monohydric alcohols, etc.

[0085] Examples of dibasic acids include aliphatic dibasic acids such as maleic acid, fumaric acid, itaconic acid, oxalic acid, malonic acid, succinic acid, dodecylsuccinic acid, dodecenylsuccinic acid, adipic acid, azelaic acid, sebacic acid, and decane-1,10-dicarboxylic acid; and aromatic dibasic acids such as phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrabromophthalic acid, tetrachlorophthalic acid, HET acid, himic acid, isophthalic acid, terephthalic acid, and 2,6-naphthalenedicarboxylic acid. Derivatives of dibasic acids include carboxylic acid halides, esters, and acid anhydrides of the above aliphatic and aromatic dibasic acids.

[0086] Examples of dihydric alcohols include aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, and neopentyl glycol; bisphenols such as bisphenol A and bisphenol F; alkylene oxide adducts of bisphenol A such as an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A; and aralkylene glycols such as xylylene glycol.

[0087] Examples of the trifunctional or higher polybasic acids and anhydrides thereof include trimellitic acid, trimellitic anhydride, 1,3,5-cyclohexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid, methylcyclohexene tricarboxylic acid, methylcyclohexene tricarboxylic anhydride, pyromellitic acid, and pyromellitic anhydride.

[0088] <Charge control agents and charge control resins> The toner particles may contain a charge control agent and / or a charge control resin. Known charge control agents can be used, and charge control agents that have a high triboelectric charging speed and can stably maintain a constant triboelectric charge amount are particularly preferred. Furthermore, when the toner particles are produced by a suspension polymerization method, charge control agents that have low polymerization inhibition properties and are substantially free of solubilized substances in aqueous media are particularly preferred.

[0089] Examples of compounds that control the toner to be negatively charged include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic and dicarboxylic acid-based metal compounds, aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, and charge control resins.

[0090] It is preferable that a charge control resin having a structure represented by the following formula (5) as an ionic functional group is present on the surface of the toner particles. The charge control resin is preferably a vinyl resin, and more preferably a styrene resin. [ka] In formula (5), R 1 are each independently an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, n is an integer of 0 to 3, and * is a bonding site to the polymer. The inclusion of the charge control resin improves charge buildup and charge stability, as well as environmental stability. The content of the charge control resin in the toner particles is preferably 0.1 to 3.0 parts by mass, and more preferably 0.2 to 1.0 part by mass, per 100 parts by mass of the binder resin.

[0091] The resin having an ionic functional group may be any resin having the ionic functional group of formula (5). For example, a polymer of vinyl salicylic acid or 1-vinyl phthalate is preferred. The electronic control resin is preferably a vinyl resin (more preferably a styrene resin) having a structure derived from a monomer represented by formula (6) below.

[0092] [ka]

[0093] R 1Examples of the alkyl group in (a) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a s-butyl group, and a t-butyl group, and examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group. The main chain structure of the polymer is not particularly limited. Examples include vinyl polymers, polyester polymers, polyamide polymers, polyurethane polymers, and polyether polymers. Hybrid polymers that combine two or more of these polymers are also included. Among these, vinyl polymers are preferred in terms of adhesion to the toner base particles.

[0094] Examples of substances that control the positive charge of toner include nigrosine and its modifications with fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate, and their analogs; onium salts such as phosphonium salts and their lake pigments; triphenylmethane dyes and their lake pigments (lacquering agents include phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide compounds, etc.); metal salts of higher fatty acids, and charge control resins.

[0095] The toner particles preferably contain a charge control resin that controls the toner to a positive charge. In particular, the toner preferably contains a charge control resin containing a quaternary ammonium salt and a quaternary ammonium base. By containing the above, the hydrotalcite can be properly fixed to the toner particles, and the charge rise property and charge stability can be improved.

[0096] <Release agent> The toner may contain a known wax as a release agent. Specific examples include petroleum waxes such as paraffin wax, microcrystalline wax, and petroleum waxes and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes produced by the Fischer-Tropsch process and derivatives thereof, polyolefin waxes such as polyethylene and polypropylene and derivatives thereof, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, ester waxes, etc. Here, the derivatives include oxides, block copolymers with vinyl monomers, and graft modified products.

[0097] Ester waxes can be monofunctional ester waxes, difunctional ester waxes, or multifunctional ester waxes such as tetrafunctional and hexafunctional. Examples of aliphatic ester waxes are listed below. The functionality indicates the number of ester groups contained in one molecule. For example, behenyl behenate is a monofunctional ester wax, and dipentaerythritol hexabehenate is called a hexafunctional ester wax.

[0098] As described above, the toner particles preferably contain an ester wax. The ester wax is preferably a polyfunctional ester wax having two or more ester groups, and more preferably a bifunctional ester wax having two ester groups.

[0099] The monofunctional aliphatic ester wax may be a condensate of a monocarboxylic acid having from 4 to 28 carbon atoms and a monoalcohol having from 4 to 28 carbon atoms. For example, at least one selected from the group consisting of stearyl stearate, behenyl stearate, stearyl behenate, and behenyl behenate is preferred, and at least one selected from the group consisting of behenyl behenate and behenyl stearate is more preferred.

[0100] As the bifunctional aliphatic ester wax, a condensation product of a dicarboxylic acid and a monoalcohol, or a condensation product of a diol and a monocarboxylic acid can be used. Dicarboxylic acids include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid. Examples of diols include ethylene glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0101] The monoalcohol to be condensed with the dicarboxylic acid is preferably an aliphatic alcohol, specifically tetradecanol, pentadecanol, hexadecanol, or heptadecanol. , octadecanol, nonadecanol, eicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, octacosanol, and the like.

[0102] Examples of the monocarboxylic acid to be condensed with the diol include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, tuberculostearic acid, arachidic acid, behenic acid, lignoceric acid, and cerotic acid.

[0103] Examples of trifunctional ester waxes include condensation products of glycerin compounds and monofunctional aliphatic carboxylic acids.

[0104] Examples of tetrafunctional ester waxes include condensates of pentaerythritol and monofunctional aliphatic carboxylic acids, and condensates of diglycerin and aliphatic carboxylic acids. Examples of pentafunctional ester waxes include condensates of triglycerin and monofunctional aliphatic carboxylic acids. Examples of hexafunctional ester waxes include condensates of dipentaerythritol and monofunctional aliphatic carboxylic acids, and condensates of tetraglycerin and monofunctional aliphatic carboxylic acids.

[0105] The content of the release agent is preferably 1.0 to 30.0 parts by mass relative to 100.0 parts by mass of the binder resin. The content of the ester wax in the toner particles is preferably 1.0 to 10.0 parts by mass, more preferably 2.0 to 8.0 parts by mass, relative to 100 parts by mass of the binder resin.

[0106] <Coloring agent> The toner particles may contain a colorant. Known pigments and dyes can be used as the colorant. Pigments are preferred as the colorant because they have excellent weather resistance. Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds. Specific examples include: CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62 and 66.

[0107] Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specific examples include CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221 and 254, and CI Pigment Violet 19.

[0108] Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples include the following: CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185, 191 and 194.

[0109] Examples of black colorants include those toned to black using the above yellow, magenta, and cyan colorants, as well as carbon black and magnetic materials. These colorants can be used alone or in a mixture, or in the form of a solid solution. The colorant is preferably used in an amount of 1.0 to 20.0 parts by mass per 100.0 parts by mass of the binder resin. In addition, the manufacturing method in an aqueous medium using a magnetic material, which will be described later, When the above method is applied, a hydrophobic treatment may be carried out in order to stably contain the magnetic material in the resin.

[0110] <Average circularity of toner> The average circularity of the toner is preferably 0.960 or more and 0.995 or less. When the average circularity of the toner is in the above range, the charge rise property is improved. The method for measuring the average circularity of the toner will be described later.

[0111] <Toner manufacturing method> The method for producing the toner is not particularly limited, and known methods such as a pulverization method, a suspension polymerization method, a solution suspension method, an emulsion aggregation method, a dispersion polymerization method, etc. Among these, the suspension polymerization method is preferred because it allows the average circularity of the toner to be highly controlled. The weight average particle size (D4) of the toner particles is preferably 4.0 to 12.0 μm, and more preferably 5.0 to 10.0 μm.

[0112] [Methods for measuring each physical property] Next, the measurement methods for each physical property will be described. <Method for isolating strontium titanate particles A, silica particles B, and hydrotalcite particles C> When measuring the physical properties of the strontium titanate fine particles A, silica fine particles B, and hydrotalcite particles C from the toner, as well as the toner particles, the strontium titanate fine particles A and other external additives can be separated from the toner and then measured. The toner is ultrasonically dispersed in methanol to remove strontium titanate particles A and other external additives, and then allowed to stand for 24 hours. The settled toner particles are separated and collected from the strontium titanate particles A and other external additives dispersed in the supernatant, and the toner particles can be isolated by thoroughly drying. The supernatant can also be centrifuged to isolate strontium titanate particles A, silica particles B, and hydrotalcite particles C.

[0113] <Contents of strontium titanate particles A, silica particles B, and hydrotalcite particles C> Strontium titanate fine particles A, silica fine particles B, and hydrotalcite particles C are isolated from the toner using the method described above. The masses of the obtained toner particles, strontium titanate fine particles A, silica fine particles B, and hydrotalcite particles C are measured. From the mass of the toner particles obtained by these methods and the masses of the strontium titanate fine particles A, silica fine particles B, and hydrotalcite particles C, the content of each particle per 100 parts by mass of the toner particles is calculated.

[0114] <Methods for measuring the number average particle size of primary particles of strontium titanate fine particles A, the number average particle size of Si-containing protrusions, the number average particle size of silica fine particles B, and the number average particle size of hydrotalcite particles C> The number average particle size of the primary particles of the external additive such as strontium titanate microparticles A and the number average particle size of the primary particles of the Si-containing protrusions are measured using a transmission electron microscope (TEM) "JEM2800" (manufactured by JEOL Ltd.) The strontium titanate microparticles A, silica microparticles B, and hydrotalcite particles C (hereinafter also simply referred to as external additives) separated by the above-mentioned procedure can be used. First, the measurement sample was prepared. 1 mL of isopropanol was added to 5 mg of each external additive to be measured, and the mixture was dispersed for 5 minutes using an ultrasonic disperser (ultrasonic cleaner). Next, a drop of the dispersion liquid was placed on a TEM microgrid (150 mesh) with a support film and allowed to dry to prepare the measurement sample.

[0115] Next, images are taken using a transmission electron microscope (TEM) at an accelerating voltage of 200 kV at a magnification (e.g., 200k to 1M) that allows sufficient measurement of the external additives in the field of view, and the particle sizes of 100 randomly selected primary particles of the external additives are measured to determine the number-average particle size. The particle size of the primary particles is measured using the image processing software "Image-Pro Plus ver. 4.0 (manufactured by Media Cybernetics)." The particle size of the external additive other than the convex portions is measured by measuring the major axis. The convex portions will be described later.

[0116] The presence of Si-containing convex portions is determined by observing secondary electron image (SEI) and EDS mapping measurements of the strontium titanate microparticles A separated by the above-mentioned method using a transmission electron microscope (TEM) "JEM2800" (manufactured by JEOL Ltd.). The EDS mapping measurement uses a silicon drift detector with a large detection element area, allowing for highly sensitive EDS mapping measurements. The conditions are as follows:

[0117] (Shape image acquisition conditions) Mode: STEM observation mode Accelerating voltage: 200 kV Magnification: 1,000,000x Probe size: 1 nm Detector: Secondary electron detector (SEI detector) SEI image size: 1024 x 1024 pixels

[0118] (STEM-EDS elemental mapping image acquisition conditions) A STEM-EDS elemental mapping image is acquired in the same field of view as the SEI image observation field. EDS detector: JEOL JED-2300T dry SD100GV detector (detector area: 100 mm 2 ) EDS analyzer: Thermo Fisher Scientific NORAN System 7 Drift correction factor: 2 Dwell Time: 30 μs Accumulation count: 100 frames X-ray CountRate:4000~10000cps Elemental mapping image size: 256 x 256 pixels Quantitative map images were extracted from the collected spectral mapping data using the quantitative map mode in the measurement command of the NORAN System 7. The settings were as follows: Kernel size: 3×3 Quantitative map setting: High (slow) Filter Fit Type: High Precision (Slow)

[0119] First, a morphology image of strontium titanate microparticle A is obtained. Then, EDS elemental quantitative mapping images of Si and Sr elements are obtained at the same position and the same magnification, and these EDS elemental mapping images are overlaid. It is difficult to precisely separate the Si-containing portions where the Si mapping and Sr mapping overlap. On the other hand, at the periphery of strontium titanate microparticle A, there is a region where only Si is mapped outside the Sr mapping region, so the Si-containing portions can be clearly identified. In the periphery where Si is confirmed to be contained, convex portions are identified from the previously obtained morphology image. In the convex portions observed in the Si-containing periphery, a straight line is drawn connecting the valleys at both ends of the convex portion, and in this case, a convex portion is defined as a convex portion where the distance between the apex of the convex and the line is 1 nm or more. The length of the line connecting the valleys at both ends of the convex portion is the particle size of the convex portion.

[0120] <Si / Sr ratio of strontium titanate particle A> The Si and Sr contents (mass) of strontium titanate microparticles A can be determined using an X-ray fluorescence analyzer. Using a wavelength dispersive X-ray fluorescence analyzer, Axios advanced (manufactured by PANalytical), 1 g of sample is weighed into a cup for powder measurement recommended by PANalytical with a special film attached, and the elements from Na to U in strontium titanate microparticles A are measured using the FP method under atmospheric pressure in a He atmosphere. In this case, assuming that all detected elements are oxides, and their total mass is set to 100%, the content (mass%) of Si oxide and Sr oxide relative to the total mass is calculated as an oxide equivalent value using the software SpectraEvaluation (version 5.0L).Then, the Si / Sr (mass ratio) is calculated by subtracting oxygen from the quantitative results.

[0121] <Measurement of C content in strontium titanate fine particles A> The amount of carbon (C) derived from the hydrophobic treatment agent in the strontium titanate fine particles A is measured using a carbon / sulfur analyzer manufactured by HORIBA (product name: EMIA-320). Accurately weigh 0.3 g of the sample strontium titanate fine particles A and place it in the crucible for the carbon / sulfur analyzer. Add 0.3 g ± 0.05 g of tin (supplementary part number 9052012500) and 1.5 g ± 0.1 g of tungsten (supplementary part number 9051104100) as combustion improvers. Then, following the instructions in the instruction manual for the carbon / sulfur analyzer, the silica microparticles are heated to 1100°C in an oxygen atmosphere. This causes the hydrophobic groups derived from the hydrophobic treatment agent on the surface of strontium titanate microparticle A to thermally decompose into CO2, and the amount of CO2 is measured. The amount of C (mass%) contained in strontium titanate microparticle A is calculated from the amount of CO2 obtained.

[0122] <Measurement of powder resistivity of strontium titanate fine particle A> The resistance of strontium titanate microparticles A is measured using the measurement device shown in Figures 2A and 2B. When measuring a sample, the sample is left in an environment of 23°C and 50% RH for 24 hours before measurement. The resistance measurement cell A has a cross-sectional area of ​​2.4 cm. 2 It consists of a cylindrical PTFE resin container 15 with a hole, a lower electrode (made of stainless steel) 16, a support base (made of PTFE resin) 17, and an upper electrode (made of stainless steel) 18. The cylindrical PTFE resin container 15 is placed on the support base 17, and 0.7 g of sample 19 is filled in. The upper electrode 18 is placed on the filled sample 19, and the thickness of the sample is measured. If the thickness without a sample is D1 (blank) (Figure 2A), the actual thickness of the sample when 0.7 g is filled is d, and the thickness when the sample is filled is D2 (sample) (Figure 2B), the thickness of the sample d can be expressed by the following formula. d = D2 (sample) - D1 (blank)

[0123] Then, a voltage is applied between the electrodes, and the resistivity can be determined by measuring the current that flows at that time. For the measurement, an electrometer 20 (Kesley 6517, manufactured by Kesley) and a computer 21 for control are used. The measurement conditions are: contact area S between the sample and the electrodes = 2.4 cm 2 The load on the upper electrode is 230 g. The voltage application conditions are as follows: an IEEE-488 interface is used to control between the control computer and the electrometer, and the electrometer's auto-range function is used to apply voltages of 1 V, 2 V, 4 V, 8 V, 16 V, 32 V, 64 V, 128 V, 256 V, 512 V, and 1000 V for 1 second each to perform screening. At this time, the electrometer determines whether it is possible to apply up to 1000V (for example, for a sample thickness of 1.00mm, the electric field strength is 10000V / cm), and if an overcurrent flows, "VOLTAGE SOURCE OPERATE" flashes. Then, the applied voltage is lowered, and the applicable voltage is further screened, and the maximum applied voltage is automatically set. Then, the actual measurement is carried out.

[0124] Measure the resistance value from the current value after holding the voltage obtained by dividing the maximum voltage value into five equal parts for 30 seconds for each step. For example, when the maximum applied voltage is 1000V, apply the voltage in the order of increasing and then decreasing in steps of 200V, which is 1 / 5 of the maximum applied voltage, i.e., 200V (step 1), 400V (step 2), 600V (step 3), 800V (step 4), 1000V (step 5), 1000V (step 6), 800V (step 7), 600V (step 8), 400V (step 9), 200V (step 10). Measure the resistance value from the current value after holding for 30 seconds at each step. By processing this with a computer, calculate the electric field strength and specific resistance and plot them on a graph. Read the specific resistance at an electric field strength of 1000V / cm from the plot. The specific resistance and electric field strength are obtained by the following formulas. Specific resistance (Ω·cm) = (Applied voltage (V) / Measured current (A)) × S (cm 2 ) / d (cm) Electric field strength (V / cm) = Applied voltage (V) / d (cm)

[0125] <Measurement of the weight average particle size (D4) of toner particles> The weight average particle size (D4) of toner particles is measured with a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.) equipped with a 100μm aperture tube and the dedicated software "Beckman Coulter Multisizer 3 Version3.51" (manufactured by Beckman Coulter, Inc.) attached for setting measurement conditions and analyzing measurement data, at an effective measurement channel number of 25,000 channels, and the measurement data is analyzed and calculated.

[0126] <Calculation method of SP value> Follow the calculation method proposed by Fedors. For atoms or atomic groups in the molecular structure, obtain the evaporation energy (Δei) (cal / mol) and molar volume (Δvi) (cm 3 / mol) from the table described in "polym.Eng.Sci., 14(2), 147 - 154(1974)". (4.184×ΣΔei / ΣΔvi)1 / 2 SP value (J / cm 3 ) 1 / 2 Let's say.

[0127] <Method for measuring average circularity of toner> The average circularity of the toner and toner particles is measured and analyzed under the following conditions using a flow particle image analyzer (product name: FPIA-3000, manufactured by Sysmex Corporation). The specific measurement method is as follows. First, 20 mL of ion-exchanged water from which impurities such as solids have been removed is placed in a glass container, and 0.2 mL of a solution prepared by diluting a dispersant (product name: Contaminon N, manufactured by Wako Pure Chemical Industries, Ltd., a 10% by weight aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder) three times by weight with ion-exchanged water is added. 0.02 g of the sample to be measured is then added, and the mixture is dispersed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. The dispersion is then cooled appropriately so that the temperature is between 10°C and 40°C. A tabletop ultrasonic cleaner disperser with an oscillation frequency of 50 kHz and an electrical output of 150 W (e.g., "VS-150" (Velvoclear)) is used as the ultrasonic disperser. A predetermined amount of ion-exchanged water is placed in the water tank, and 2 mL of Contaminon N is added to the water tank.

[0128] For the measurement, a flow-type particle image analyzer equipped with "UPlanApro" (magnification 10x, numerical aperture 0.40) was used as the objective lens, and Particle Sheath (product name: PSE-900A, manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion liquid prepared according to the above procedure was introduced into the flow-type particle image analyzer, and 3,000 toner particles were measured in HPF measurement mode and total count mode. The binarization threshold for particle analysis was set to 85%, and the analyzed particles were counted. The diameter is limited to a circle-equivalent diameter of 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner particles is determined. Before starting the measurement, automatic focusing is performed using standard latex particles (for example, "RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A" manufactured by Duke Scientific, diluted with ion-exchanged water).

[0129] <Method for measuring the Bragg angle Θ of strontium titanate fine particle A> The Bragg angle Θ of the inorganic fine particles is measured using a powder X-ray diffractometer "SmartLab" (manufactured by Rigaku Corporation, a horizontal sample type high-power X-ray diffractometer). The Sb / Sa ratio is calculated from the peaks obtained using the analytical software "PDXL2 (version 2.2.2.0)" that comes with the above-mentioned device. The measurement sample is a toner or strontium titanate fine particles isolated from the toner, and is measured according to the following procedure. In the following examples, the measurement is performed using the produced strontium titanate fine particles A.

[0130] (Sample preparation) The measurement sample is uniformly placed in a 0.5 mm diameter Boro-Silicate capillary (manufactured by W. Muller) and then measured.

[0131] (Measurement conditions) ·Tube:Cu ·Optical system: CBO-E Sample stage: Capillary sample stage Detector: D / tex Ultra250 detector Voltage: 45kV ·Current: 200mA ·Starting angle: 10° End angle: 90° Sampling width: 0.02° Speed ​​measurement time setting value: 10 IS:1mm RS1: 20mm RS2: 20mm Attenuator: Open Capillary rotation speed setting: 100 For other conditions, the initial settings of the device are used.

[0132] (analysis) First, the obtained peaks are separated using the software "PDXL2" that comes with the instrument. Peak separation is performed by performing optimization using the "split Voigt function" that can be selected in PDXL, and the obtained integrated intensity values ​​are used. This determines the 2Θ value of the diffraction peak top and its area. Sb / Sa is calculated from the peak area at the specified 2Θ value. If there is a large discrepancy between the calculated peak separation results and the measured spectrum, you can manually set the baseline or take other measures to adjust the calculated results and the measured spectrum so that they match. [Example]

[0133] The toner of the present disclosure will be described in detail below using examples and comparative examples, but the present disclosure is not limited to these examples. Unless otherwise specified, all values ​​are by mass.

[0134] <Production example of strontium titanate fine particles A1> Metatitanic acid produced by the sulfuric acid method was deironized and bleached, then desulfurized by adding a 3 mol / L aqueous solution of sodium hydroxide to adjust the pH to 9.0, and then neutralized to pH 5.6 with 5 mol / L hydrochloric acid, filtered, and washed with water. Water was added to the washed cake to make a 1.90 mol / L slurry in terms of TiO2, and hydrochloric acid was added to adjust the pH to 1.4, which was then subjected to peptization. After desulfurization and peptization, 1.90 moles of metatitanic acid was collected in terms of TiO2 and placed in a 3 L reaction vessel. 2.185 moles of strontium chloride aqueous solution was added to the peptized metatitanic acid slurry so that the SrO / TiO2 (molar ratio) was 1.15, and the TiO2 concentration was then adjusted to 1.039 moles / L. Next, an aqueous sodium silicate solution was prepared so that the amount of Si added was equivalent to 5.0 mol% relative to strontium, and the solution was heated to 90°C while stirring and mixing. 440 mL of a 10 mol / L aqueous sodium hydroxide solution was then added over 55 minutes under ultrasonic vibration.

[0135] After that, stirring was continued at 95°C for 45 minutes, and then the mixture was poured into ice water to rapidly cool it down and terminate the reaction. The reaction slurry was heated to 70°C, and 12 mol / L hydrochloric acid was added until the pH reached 5.0. Stirring was continued for 1 hour, and the resulting precipitate was washed by decantation. After separation by filtration, it was dried in the air at 120°C for 8 hours. Next, 300 g of the dried product was placed in a dry particle compositer (Nobilta NOB-130, manufactured by Hosokawa Micron). Treatment was performed for 10 minutes at a treatment temperature of 30°C with a rotary treatment blade at 90 m / sec. Hydrochloric acid was further added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was washed by decantation. The slurry containing the precipitate was adjusted to 40°C, and hydrochloric acid was added to adjust the pH to 2.5.

[0136] Next, 14% by mass of isobutyltrimethoxysilane based on the solid content was added after stirring for 1 hour, and stirring was continued for 10 hours. 5N sodium hydroxide solution was added to adjust the pH to 6.5, and stirring was continued for 1 hour. After filtering and washing, the resulting cake was dried in air at 120°C for 8 hours. The resulting strontium titanate microparticles were designated strontium titanate microparticles A1. On the surface of the strontium titanate microparticles A1, there were protrusions formed by partly buried silica microparticles or adhered silica microparticles. The particle diameter of the silica microparticles forming the protrusions was less than 5 nm.

[0137] <Production Examples of Strontium Titanate Microparticles A2 to A22> In the manufacturing example of strontium titanate microparticles A1, the amount of Si added, the surface treatment components and the amount added were changed as shown in Table 1, and the addition rate of 440 mL of 10 mol / L sodium hydroxide aqueous solution, the stirring conditions, the ultrasonic dispersion conditions, and the processing time using the dry particle composite device were appropriately adjusted to obtain strontium titanate microparticles A2 to 22. On the surfaces of the strontium titanate microparticles A2 to A17, there were convex portions in which silica microparticles were partially buried or convex portions formed by the adhesion of silica microparticles. The particle diameter of the silica microparticles forming the convex portions was less than 5 nm. On the other hand, no convex portions of silica fine particles were present on the surfaces of the strontium titanate fine particles A18 to A22.

[0138] <Production example of silica fine particles B1> Untreated fumed silica (BET specific surface area 200m 2 / g) was placed in a reactor and heated to 330°C while being fluidized by stirring. Next, 20 parts of dimethyl silicone oil (polydimethylsiloxane: KF-96-50CS manufactured by Shin-Etsu Chemical Co., Ltd.) was sprayed onto 100 parts of untreated dry silica as a surface treatment agent. After that, heating and stirring were continued for 1 hour to cause a reaction, thereby coating the mixture and obtaining silica fine particles B1.

[0139] <Production Examples of Silica Fine Particles B2 to B4> Silica fine particles B2 to B4 were obtained in the same manner as in the production example for silica fine particles B1, except that the BET specific surface area of ​​the untreated dry silica and the parts number of the surface treatment agent were changed as shown in Table 2.

[0140] <Production example of hydrotalcite particles C1> A mixed aqueous solution of 1.03 mol / L magnesium chloride and 0.239 mol / L aluminum sulfate (liquid A), a 0.753 mol / L sodium carbonate aqueous solution (liquid B), and a 3.39 mol / L sodium hydroxide aqueous solution (liquid C) were prepared. Next, liquids A, B, and C were poured into a reaction vessel using a metering pump at a flow rate such that the volume ratio of liquid A to liquid B was 4.5:1. The pH value of the reaction solution was maintained in the range of 9.3 to 9.6 using liquid C, and the reaction temperature was 40°C to produce a precipitate. After filtration and washing, the precipitate was re-emulsified in ion-exchanged water to obtain a raw material hydrotalcite slurry. The hydrotalcite concentration in the obtained hydrotalcite slurry was 5.6% by mass. The mixture was then filtered through a membrane filter with a pore size of 0.5 μm and washed with ion-exchanged water. The resulting hydrotalcite was dried overnight in a vacuum at 40° C. and then crushed to a desired particle size to obtain hydrotalcite particles C1.

[0141] <Production Examples of Hydrotalcite Particles C2 to C5> Except for changing the crushing treatment conditions so as to obtain particle sizes shown in Table 3, the same procedures as in the production example of hydrotalcite particles C1 were carried out to obtain hydrotalcite particles C2 to C5.

[0142] <Production Example of Polyester Resin D1> 100 parts by mass of a mixture of raw material monomers mixed in the charging ratios shown in Table 4 and 0.55 parts by mass of tin di(2-ethylhexanoate) as a catalyst were placed in a 6-liter four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, and reacted under a nitrogen atmosphere at 200°C for 6 hours. Trimellitic anhydride was then added at 210°C, and the reaction was continued under a reduced pressure of 40 kPa until the weight-average molecular weight (Mw) reached 12,100. The resulting polyester resin was designated polyester resin D1.

[0143] <Production Example of Polyester Resin D2> Polyester resin D2 was obtained in the same manner as in the production example of polyester resin D1, except that the raw material monomers were changed as shown in Table 4.

[0144] <Production example of charge control resin E> 9.2 g of the polymerizable monomer shown in the following structural formula (6) and 60.1 g of styrene were dissolved in 42.0 mL of DMF, stirred for 1 hour while bubbling with nitrogen, and then heated to 110°C. A mixture of 2.1 g of tert-butylperoxyisopropyl monocarbonate (manufactured by NOF Corporation, product name Perbutyl I) as an initiator and 42 mL of toluene was added dropwise to the reaction solution. The reaction was continued for another 4 hours at 110°C. The mixture was then cooled and added dropwise to 1 L of methanol to obtain a precipitate. The resulting precipitate was dissolved in 120 mL of THF and then added dropwise to 1.80 L of methanol to obtain a white precipitate. The precipitate was filtered and dried under reduced pressure at 90°C to obtain Charge Control Resin E.

[0145] [ka]

[0146] <Production example of vinyl resin F> 300 parts of xylene was charged into an autoclave equipped with a stirrer, a thermometer, a nitrogen inlet tube, a pressure reducing device, and a dehydration tube, and heated while replacing the atmosphere with nitrogen to reflux at a liquid temperature of 140° C. A mixed liquid of the following materials was added thereto, and polymerization was carried out for 5 hours at a polymerization temperature of 160° C. and a pressure during reaction of 0.150 MPa. Styrene 91.50 parts, butyl acrylate 1.00 parts, 2.50 parts of methyl methacrylate, 2.50 parts methacrylic acid 2.50 parts of 2-hydroxyethyl methacrylate, Polymerization initiator (di-tert-butyl peroxide) 2.00 parts Thereafter, a solvent removal step was carried out under reduced pressure for 3 hours to remove xylene, and the resulting mixture was pulverized to obtain vinyl resin F.

[0147] <Production Example of Toner Particle 1> Toner particles were prepared by the following procedure. (Preparation of pigment masterbatch) The following materials were charged into an attritor (Mitsui Miike Chemical Engineering Co., Ltd.), and further dispersed using zirconia particles with a diameter of 1.7 mm at 220 rpm for 5 hours to obtain a pigment master batch. Styrene 60.0 parts Cyan pigment (Dainichi Seika Chemicals Co., Ltd., CI Pigment Blue 15:3) 7 parts

[0148] (Preparation of first aqueous medium) 2.9 parts of sodium phosphate dodecahydrate was added to 353.8 parts of ion-exchanged water and heated to 60°C while stirring using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). After that, an aqueous calcium chloride solution prepared by adding 1.7 parts of calcium chloride dihydrate to 11.7 parts of ion-exchanged water and an aqueous magnesium chloride solution prepared by adding 0.5 parts of magnesium chloride to 15.0 parts of ion-exchanged water were added and stirring was continued to obtain a first aqueous medium containing a dispersion stabilizer.

[0149] (Preparation of Polymerizable Monomer Composition) Styrene 15.0 parts n-Butyl acrylate 25.0 parts Bifunctional ester wax (ethylene glycol distearate) 5.0 parts Hydrocarbon wax, melting point: 79°C 5.0 parts Pigment masterbatch 67.0 parts Polyester resin D1 3.0 parts Charge control resin E 0.5 parts Positive charge control resin (product name: FCA-676P, manufactured by Fujikura Kasei Co., Ltd.) Quaternary ammonium group-containing styrene acrylic resin) 0.1 parts The above materials were uniformly dispersed and mixed using an attritor (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and then heated to 60°C. Paraffin wax (HNP- 9) 8.0 parts of the above was added, mixed and dissolved to obtain a polymerizable monomer composition.

[0150] (Preparation of second aqueous medium) 0.6 parts of sodium phosphate dodecahydrate was added to 166.8 parts of ion-exchanged water, and the mixture was heated to 60°C while stirring using a paddle stirring blade. After that, an aqueous calcium chloride solution prepared by adding 0.3 parts of calcium chloride dihydrate to 2.3 parts of ion-exchanged water was added, and stirring was continued to obtain a second aqueous medium containing a dispersion stabilizer.

[0151] (granulation) The polymerizable monomer composition was added to the first aqueous medium, and the granulation liquid was treated using a Cavitron (manufactured by Eurotech) at a rotor peripheral speed of 29 m / s for 1 hour to uniformly disperse and mix. 7.0 parts of t-butyl peroxypivalate was then added as a polymerization initiator, and the mixture was granulated at 60°C under a N2 atmosphere with a Clearmix (manufactured by M Technique) at a peripheral speed of 22 m / s for 10 minutes, to obtain a granulation liquid containing droplets of the polymerizable monomer composition.

[0152] (Polymerization / Distillation / Drying) The granulation liquid was added to the second aqueous medium, and the mixture was reacted at 74°C for 3 hours while stirring with a paddle impeller. After the reaction was completed, the mixture was heated to 98°C and distilled for 3 hours to obtain a reaction slurry. Then, in a cooling step, water at 0°C was added to the reaction slurry, and the reaction slurry was cooled from 98°C to 45°C at a rate of 100°C / min, and then further heated to 50°C and maintained at that temperature for 3 hours. Thereafter, the reaction slurry was allowed to cool to 25° C. After being allowed to cool, hydrochloric acid was added to the reaction slurry, which was then washed, filtered, and dried to obtain toner particles 1 having a weight average particle size of 7.5 μm.

[0153] <Production Example of Toner Particle 2> Toner particles 2 having a weight average particle size of 7.6 μm were obtained in the same manner as toner particles 1, except that "polyester resin D1" was changed to "polyester resin D2."

[0154] <Production Example of Toner Particle 3> Toner particles 3 having a weight average particle size of 7.4 μm were obtained in the same manner as toner particles 1, except that "polyester resin D1" was changed to "vinyl resin F."

[0155] <Production Example of Toner Particle 4> Toner particles 4 having a weight average particle size of 7.4 μm were obtained in the same manner as toner particles 1, except that "polyester resin D1" was changed to "vinyl resin F" and the "positive charge control resin" was omitted.

[0156] <Production Example of Toner Particle 5> Toner particles 5 having a weight average particle size of 7.4 μm were obtained in the same manner as toner particles 1, except that ``polyester resin D1'' was changed to ``vinyl resin F'' and ``charge control resin E'' and ``positive charge control resin'' were omitted.

[0157] <Production Example of Toner Particle 6> Toner particles 6 having a weight average particle size of 7.4 μm were obtained in the same manner as toner particles 1, except that the bifunctional ester wax (ethylene glycol distearate) was changed to tetrafunctional ester wax (pentaerythritol tetrastearate).

[0158] <Production Example of Toner Particle 7> The same as toner particle 1, except that "difunctional ester wax (ethylene glycol distearate)" was changed to "trifunctional ester wax (glycerin tribehenate)". As a result, toner particles 7 having a weight average particle size of 7.4 μm were obtained.

[0159] <Production Example of Toner Particle 8> Toner particles 8 having a weight average particle size of 7.4 μm were obtained in the same manner as toner particles 1, except that the bifunctional ester wax (ethylene glycol distearate) was changed to monofunctional ester wax (behenyl behenate).

[0160] <Production Example of Toner Particle 9> Toner particles 9 having a weight average particle size of 7.4 μm were obtained in the same manner as toner particles 1, except that "ester wax (ethylene glycol distearate)" was omitted.

[0161] <Production Example of Toner Particles 10> (Preparation of styrene acrylic resin particle dispersion) Styrene: 75 parts n-Butyl acrylate: 25 parts The above materials were mixed and dissolved, and a solution of 1.0 part of anionic surfactant (Dowfax, manufactured by Dow Chemical Co.) dissolved in 60 parts of ion-exchanged water was added to the mixture, followed by dispersion and emulsification in a flask to prepare a monomer emulsion. Next, 2.0 parts of anionic surfactant (Dowfax, manufactured by Dow Chemical Co.) were dissolved in 90 parts of ion-exchanged water, to which 2.0 parts of the monomer emulsion was added, and then 10 parts of ion-exchanged water in which 1.0 part of ammonium persulfate had been dissolved was added.

[0162] The remainder of the monomer emulsion was then added over 3 hours, and the flask was purged with nitrogen. The solution in the flask was then heated to 65°C in an oil bath while stirring, and emulsion polymerization was continued for 5 hours to obtain a styrene-acrylic resin particle dispersion. The solid content of the styrene-acrylic resin particle dispersion was adjusted to 20% by mass by adding ion-exchanged water.

[0163] (Preparation of Colorant Particle Dispersion) Cyan pigment (Dainichi Seikagaku Co., Ltd., CI Pigment Blue 15:3) 35 parts Anionic surfactant (Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen R) 2 parts 250 parts ion-exchanged water The above ingredients were mixed, dissolved, and dispersed for about 1 hour using a high-pressure impact disperser, Ultimizer (HJP30006, manufactured by Sugino Machine Co., Ltd.), to obtain a colorant particle dispersion. The volume average particle diameter D 50v The particle size was 150 nm. Then, ion-exchanged water was added to adjust the solid content to 20% by mass.

[0164] (Preparation of Release Agent Particle Dispersion) 200 parts paraffin wax (Nippon Seiro Co., Ltd., HNP-9) Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku): 10.0 parts Ion-exchanged water: 20.0 parts The above materials were mixed and the release agent was dissolved in a pressure discharge homogenizer (Gaulin Homogenizer manufactured by Gaulin Co., Ltd.) at an internal liquid temperature of 120°C, after which the mixture was subjected to dispersion treatment at a dispersion pressure of 5 MPa for 120 minutes and then at 40 MPa for 360 minutes, and then cooled to obtain a dispersion liquid. Ion-exchanged water was added to adjust the solid content to 20 mass%, and this was used as a release agent particle dispersion liquid.

[0165] (Toner particle production) Styrene acrylic resin particle dispersion: 375 parts Colorant particle dispersion: 75 parts Release agent particle dispersion: 15 parts Ion-exchanged water: 750 parts Anionic surfactant (Dowfax 2A1 manufactured by The Dow Chemical Company): 3.2 parts The above material was placed in a 3-liter reaction vessel equipped with a thermometer, pH meter, and stirrer as the core forming material, and 1.0% nitric acid was added at 25°C to adjust the pH to 3.0. After that, 100 parts of a 2.0% by mass magnesium chloride aqueous solution was added as a flocculant while dispersing at 5,000 rpm using a homogenizer (Ultra Turrax T50 manufactured by IKA), and the mixture was dispersed for 6 minutes.

[0166] The mixture was then heated to 53°C in a heating water bath using a stirring blade while adjusting the rotation speed as needed to stir the mixture. The volume average particle size of the formed aggregated particles was measured using a Coulter Multisizer III. When the volume average particle size reached 5.0 μm, the temperature was maintained and the pH was adjusted to 9.0 using a 5% aqueous sodium hydroxide solution. The temperature was then raised to 90°C and maintained at 90°C for 1 hour to fuse the aggregated particles.

[0167] Hydrochloric acid was then added to adjust the pH to 5.0 at 90°C, and the mixture was stirred for an additional 30 minutes. A 0.9 mol / L Na2CO3 aqueous solution was then added, and the pH was adjusted to 5.5, and the mixture was maintained for 30 minutes. The mixture was then cooled to 25°C, filtered, and subjected to solid-liquid separation, followed by washing with ion-exchanged water. After washing, the mixture was dried in a vacuum dryer to obtain toner particles 10 with a weight-average particle diameter of 7.3 μm.

[0168] <Toner 1 manufacturing example> Strontium titanate fine particles A1 (0.6 parts), silica fine particles B1 (0.8 parts), and hydrotalcite particles C1 (0.2 parts) were externally added and mixed with 100.0 parts of toner particles 1 using an FM10C (manufactured by Nippon Coke & Engineering Co., Ltd.) The external addition conditions were as follows: the lower blade was set to A0 blade, the gap to the deflector wall was set to 20 mm, the amount of toner particles charged was 2.0 kg, and the rotation speed was 66.6 s -1 The external addition time was 10 minutes, and the cooling water temperature was 20°C and the flow rate was 10 L / min. Thereafter, the mixture was sieved through a mesh having an opening of 200 μm to obtain Toner 1.

[0169] <Production Examples of Toner 2 to Toner 47> Toners 2 to 47 were obtained in the same manner as in the production example of Toner 1, except that the combination of toner particles and external additives was changed as shown in Table 5.

[0170] <Examples 1 to 42 and Comparative Examples 1 to 5> The following actual machine evaluation was carried out using Toners 1 to 47. The evaluation results are shown in Table 6. For the evaluation, an HP LaserJet Enterprise M609dn was used with its process speed modified to 410 mm / sec. The evaluation paper was Vitality (Xerox, basis weight 75 g / m 2 , letter size) was used.

[0171] <HH ghost evaluation in high temperature and humidity environments> After leaving the image output tester and the toner cartridge filled with the toner to be evaluated in a high-temperature, high-humidity environment of 32.5°C / 80%RH for more than a day, the image shown in Figure 1 was output using the image output tester. The image shown in Figure 1 allows for strict evaluation of ghosting characteristics. Specifically, when ghosting occurs, the density of the halftone area becomes distorted after the black band at the top is output. Ghosting was evaluated based on whether the disturbance could be visually confirmed. [Evaluation criteria] A: No trace of ghosts is visible. B: The shading corresponding to the black band appears dark in the upper third of the image. C: The shading corresponding to the black band appears darker in the upper half of the image. D: The shading corresponding to the black band appears dark across the entire image. E: Shades corresponding to the black bands are clearly visible.

[0172] <LL ghost evaluation in low temperature and low humidity environment> The image output tester and the toner cartridge filled with the evaluation toner were left in a low-temperature, low-humidity environment of 10°C / 10% RH for at least one day, and then 10,000 test charts with a print ratio of 1% were printed using the image output tester. After printing 10,000 sheets, the image shown in Figure 1 was output. The image in Figure 1 allows for strict evaluation of ghosting characteristics. Specifically, when ghosting occurs, the density of the halftone area is disturbed after the black band at the top is output. Ghosting was evaluated based on whether the disturbance could be visually confirmed. [Evaluation criteria] A: No trace of ghosts is visible. B: A faint shade corresponding to the black band is seen in the upper third of the image. C: The shade corresponding to the black band is seen lightly in the upper half of the image. D: The shade corresponding to the black band is seen lightly across the entire image. E: Shades corresponding to the black bands are clearly visible.

[0173] <Charging roller (C roller) contamination evaluation> The image output tester and toner cartridge filled with the evaluation toner were left in a low-temperature, low-humidity environment of 10°C / 10% RH for at least one day, and then 10,000 test charts with a print ratio of 10% were printed using the image output tester. After printing 10,000 sheets, three halftone images with a print ratio of 23% were output. In this evaluation, if the charging roller is contaminated, the charging ability of the contaminated area decreases, causing black vertical stripes to appear when the halftone image is output. The number of vertical stripes that appeared on the three obtained halftone images was counted, and the charging roller contamination was evaluated using the following criteria. [Evaluation criteria] A: No streaks are visible. B: The width of the streaks is less than 0.5 mm, and the number of streaks is 1 or more and 3 or less. C: The width of the streaks is less than 0.5 mm, and the number of streaks is 4 or more and 6 or less. D: The width of the streaks is less than 0.5 mm, and the number of streaks is 7 or more and 9 or less. E: The number of streaks with a width of less than 0.5 mm is 10 or more, or streaks with a width of 0.5 mm or more have occurred.

[0174] <Photoreceptor contamination evaluation> The image reproduction tester and the toner cartridge filled with the toner to be evaluated were left in a high-temperature, high-humidity environment of 32.5°C / 80%RH for at least one day, and then 10,000 test charts with a print ratio of 15% were printed using the image reproduction tester. After printing 10,000 sheets, the toner coverage per unit area was 1.0 mg / cm. 2 A solid black image was outputted on the entire surface, and the surface of the photoreceptor and the solid black image were visually inspected. The contamination of the photoreceptor was evaluated according to the following criteria. [Evaluation criteria] A: No toner fusion was observed on the photoreceptor. B: A slight amount of toner fusion is observed on the photosensitive member, but it does not appear on the image. C: White dots are missing from the image on a solid black image. D: Shooting star-shaped image voids are observed from white dots on a solid black image.

[0175] <Charge rise evaluation in a high temperature and humidity environment> The image reproduction tester and the toner cartridge filled with the toner to be evaluated were left in a high-temperature, high-humidity environment of 32.5°C / 80%RH for at least one day, and then 1,000 test charts with a print ratio of 1% were printed using the image reproduction tester.Then, the tester was left in the same environment for 72 hours, and 100 sheets were printed. After printing 1,000 sheets and after leaving it for 100 sheets, the developing capacity of the toner cartridge The charge amount (μC / g) of the toner on the support was measured using a blow-off powder charge amount measuring device TB-200 (manufactured by Toshiba Chemical Co.), and the charge rise property in a high temperature and high humidity environment was evaluated. The greater the ratio of the charge amount after printing 100 sheets after being left to stand to the charge amount after printing 1000 sheets, the better the toner's charge buildup. The evaluation criteria for charge buildup were determined as follows: (charge amount after printing 100 sheets after being left to stand) / (charge amount after printing 1000 sheets) x 100, and the evaluation was based on the following criteria. [Evaluation criteria] A: 95% or more B: 90% or more but less than 95% C: 85% or more but less than 90% D: 80% or more but less than 85% E: Less than 80%

[0176] <Charging stability evaluation in low temperature and low humidity environment LL> The image reproduction tester and the toner cartridge filled with the toner to be evaluated were left in a low-temperature, low-humidity environment of 10°C / 10%RH for at least one day, and then 10,000 test charts with a print ratio of 1% were printed using the image reproduction tester. After printing 5,000 sheets and after printing 10,000 sheets, the charge amount (μC / g) of the toner on the developing carrier in the toner cartridge was measured using a blow-off powder charge amount measuring device TB-200 (manufactured by Toshiba Chemical Co., Ltd.) to evaluate the charge stability in a low-temperature, low-humidity environment. The greater the ratio of the charge amount after printing 5000 sheets to that after printing 10000 sheets, the better the charge stability of the toner. The evaluation criteria for charge stability were determined as follows: (charge amount after printing 5000 sheets) / (charge amount after printing 10000 sheets) x 100, and the evaluation was based on the following criteria. [Evaluation criteria] A: 96% or more B: 91% or more but less than 96% C: 88% or more but less than 91% D: 85% or more but less than 88% E: Less than 85%

[0177] <Environmental stability evaluation> After printing 1000 sheets in the high-temperature, high-humidity environment charge buildup evaluation and after printing 1000 sheets in the low-temperature, low-humidity environment charge stability evaluation, the charge amount (μC / g) of the toner on the developer carrier in the toner cartridge was measured using a blow-off powder charge amount measuring device TB-200 (manufactured by Toshiba Chemical Corporation) to evaluate environmental stability. The greater the ratio of charge amount in the high-temperature, high-humidity environment to that in the low-temperature, low-humidity environment, the better the environmental stability of the toner. The environmental stability evaluation criteria were determined as follows: Evaluation was based on the value of (charge amount after printing 1000 sheets in the high-temperature, high-humidity environment) / (charge amount after printing 1000 sheets in the low-temperature, low-humidity environment) × 100, and was evaluated according to the following criteria. [Evaluation criteria] A: 80% or more B: 75% or more but less than 80% C: 70% or more but less than 75% D: Less than 70%

[0178] <Low temperature fixability evaluation> For low-temperature fixability evaluation, the fixing unit of the evaluation machine is removed and the temperature of the fixing unit can be set as desired. An external fixing unit was used which was modified so that the process speed was 410 mm / sec. Using the above device, the toner amount per unit area was set to 0.5 mg / cm under normal temperature and humidity conditions (temperature 25°C, humidity 50% RH). 2 The unfixed solid black image was passed through a fixing unit whose temperature was adjusted to the set temperature. The resulting fixed image was fixed at 4.9 kPa (50 g / cm 2 The image was rubbed back and forth five times with Silbon paper under a load of 1000 kJ / cm², and the temperature at which the density loss before and after the rubbing test was 10% or less was defined as the fixing temperature. The image density was measured using a Macbeth densitometer (manufactured by Macbeth) which is a reflection densitometer, with an SPI filter. (Evaluation criteria) A: Fixing temperature is less than 200°C B: Fixing temperature is 200°C or higher and less than 210°C C: Fixing temperature is 210°C or higher and less than 220°C D: Fixing temperature is 220°C or higher

[0179] <Abrasion resistance evaluation> For the evaluation of abrasion resistance, the fixing device of the above-mentioned evaluation machine was taken outside, and an external fixing device was used which was modified so that the temperature of the fixing device could be set arbitrarily and the process speed was set to 450 mm / sec. Fixing was performed at the fixing temperature of each toner obtained in the above-mentioned low-temperature fixability evaluation. Toner loading: 0.50mg / cm 2 After obtaining a solid black unfixed image, the external fixing device was set to the fixing temperature of each toner, and fixing was performed in a normal temperature and humidity environment (temperature 25°C, humidity 50% RH). The obtained fixed image was fixed at 4.9 kPa (50 g / cm 2 A portion of the blank evaluation paper was cut out (rubbing paper) and rubbed back and forth 10 times while applying a load of 1000 kJ / cm. The reflection density of the rubbing paper after rubbing and the blank evaluation paper remaining after cutting out the rubbing paper were measured using a reflectometer (Reflectometer Model TC-6DS, manufactured by Tokyo Denshoku Co., Ltd.), and the rub resistance of the fixed image was evaluated based on the difference in reflection density. (Evaluation criteria) A: Reflection density difference is less than 1.0 B: Reflection density difference is 1.0 or more and less than 2.0 C: Reflection density difference is 2.0 or more and less than 3.0 D: Reflection density difference is 3.0 or more

[0180] [Table 1] In Table 1, the amount of Si added indicates the amount of Si added in the aqueous sodium silicate solution. The C amount indicates the C amount (carbon amount) of the strontium titanate fine particles A derived from the hydrophobic treatment agent. For example, 1.2.E+10 is 1.2 x 10 10 This indicates that

[0181] [Table 2]

[0182] [Table 3]

[0183] [Table 4] The abbreviations in the table are as follows: TPA: Terephthalic acid TMA: Trimellitic anhydride BPA(PO2): 2-mol propylene oxide adduct of bisphenol A EG: Ethylene glycol

[0184] [Table 5] In the table, MA / MC is the ratio M A / M C Shows.

[0185] [Table 6]

[0186] The present disclosure relates to the following configurations. (Configuration 1) A toner containing toner particles containing a binder resin and inorganic fine particles, The inorganic fine particles are strontium titanate fine particles A, silica fine particles B, and hydrotalcite fine particles B. Contains site particle C, Si is present on the surface of the strontium titanate microparticles A, a toner characterized in that the mass ratio of Si to Sr (Si / Sr), detected by fluorescent X-ray analysis of the strontium titanate fine particles A, satisfies the following formula (1): 0.20≦Si / Sr≦0.60 (1). (Configuration 2) The content M of the strontium titanate fine particles A relative to 100 parts by mass of the toner particles A 2. The toner according to claim 1, wherein the amount of the hydroxybenzoates is 0.1 to 1.5 parts by mass. (Configuration 3) 3. The toner according to claim 1, wherein the strontium titanate fine particles A have a number-average particle size of 25 to 80 nm. (Configuration 4) 4. The toner according to any one of configurations 1 to 3, wherein the number average particle diameter of the silica fine particles B is 5 to 50 nm. (Configuration 5) 5. The toner according to any one of configurations 1 to 4, wherein the number average particle diameter of the hydrotalcite particles C is 60 to 500 nm. (Configuration 6) The powder resistivity R of the strontium titanate fine particles A A but, 1.0×10 8 ~1.0×10 12 6. The toner according to any one of configurations 1 to 5, wherein the toner has a viscosity of Ω·cm. (Configuration 7) The content of the strontium titanate fine particles A relative to 100 parts by mass of the toner particles is M A The content of the hydrotalcite particles C relative to 100 parts by mass of the toner particles is M C Then, M C M against A The ratio value M A / M C The toner according to any one of configurations 1 to 6, which satisfies the following formula (2): 0.30≦M A / M C ≦20.0 ···(2). (Configuration 8) The toner according to any one of configurations 1 to 7, wherein the mass ratio (Si / Sr) satisfies the following formula (3): 0.26≦(Si / Sr)≦0.50 (3). (Configuration 9) The powder resistivity of the strontium titanate fine particles A is R A When this is done, the R A and the mass ratio (Si / Sr) satisfies the following formula (4): 1.7×10 8 ≦R A / (Si / Sr)≦3.0×10 12 ···(4). (Configuration 10) 10. The toner according to any one of Configurations 1 to 9, wherein the strontium titanate fine particles A have a surface on which protrusions containing Si are present. (Configuration 11) 11. The toner according to claim 10, wherein the convex portions are formed of silica fine particles. (Configuration 12) 12. The toner according to any one of configurations 1 to 11, wherein a charge control resin having a structure represented by the following formula (5) as an ionic functional group is present on the surface of the toner particles: [ka] In formula (5), R 1 are each independently an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, n is an integer of 0 to 3, and * is a bonding site to the polymer. (Configuration 13) 13. The toner according to any one of configurations 1 to 12, wherein the toner particles have polyester resin D on the surface thereof. (Configuration 14) 14. The toner according to claim 13, wherein the polyester resin D comprises at least one selected from the group consisting of a monomer unit derived from an alcohol having an alicyclic structure and a monomer unit derived from a carboxylic acid having an alicyclic structure. (Configuration 15) 15. The toner according to any one of embodiments 1 to 14, wherein the toner particles contain an ester wax. (Configuration 16) 16. The toner according to embodiment 15, wherein the ester wax is a polyfunctional ester wax having two or more ester groups. (Configuration 17) 16. The toner according to embodiment 15, wherein the ester wax is a bifunctional ester wax having two ester groups.

Claims

1. A toner containing toner particles containing a binder resin and inorganic fine particles, the inorganic fine particles contain strontium titanate fine particles A, silica fine particles B, and hydrotalcite particles C; Si is present on the surface of the strontium titanate fine particles A, a toner characterized in that the mass ratio of Si to Sr (Si / Sr), detected by fluorescent X-ray analysis of the strontium titanate fine particles A, satisfies the following formula (1): 0.20≦Si / Sr≦0.60 (1).

2. The content M of the strontium titanate fine particles A relative to 100 parts by mass of the toner particles Ａ 2. The toner according to claim 1, wherein the amount of the toner is 0.1 to 1.5 parts by mass.

3. 3. The toner according to claim 1, wherein the strontium titanate fine particles A have a number average particle size of 25 to 80 nm.

4. 3. The toner according to claim 1, wherein the number average particle diameter of the silica fine particles B is 5 to 50 nm.

5. 3. The toner according to claim 1, wherein the number average particle diameter of the hydrotalcite particles C is 60 to 500 nm.

6. The powder resistivity R of the strontium titanate fine particles A Ａ but, 1.0 x 10 ８ ~1.0 x 10 １２ 3. The toner according to claim 1, wherein the toner has a viscosity of Ω·cm.

7. The content of the strontium titanate fine particles A relative to 100 parts by mass of the toner particles is M Ａ The content of the hydrotalcite particles C relative to 100 parts by mass of the toner particles is M Ｃ When M Ｃ M against Ａ The ratio value M Ａ / M Ｃ The toner according to claim 1 or 2, wherein the following formula (2) is satisfied: 0.30≦M Ａ / M Ｃ ≦20.0 ・・・(2)。

8. The toner according to claim 1 or 2, wherein the mass ratio (Si / Sr) satisfies the following formula (3): 0.26≦(Si / Sr)≦0.50 (3).

9. The powder resistivity of the strontium titanate fine particles A is R Ａ When this is the case, the R Ａ and the mass ratio (Si / Sr) satisfies the following formula (4): 1.7×10 ８ ≦R Ａ / (Si / Sr)≦3.0×10 １２ ・・・(4)。

10. 3. The toner according to claim 1, wherein the strontium titanate fine particles A have a surface on which protrusions containing Si are present.

11. The toner according to claim 10, wherein the convex portions are formed of silica fine particles.

12. The toner according to claim 1 or 2, wherein a charge control resin having a structure represented by the following formula (5) as an ionic functional group is present on the surface of the toner particles: In formula (5), R １ are each independently an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, n is an integer of 0 to 3, and * is a bonding site with the polymer.

13. 3. The toner according to claim 1, wherein the toner particles have polyester resin D on the surface thereof.

14. The toner according to claim 13, wherein the polyester resin D has at least one selected from the group consisting of a monomer unit derived from an alcohol having an alicyclic structure and a monomer unit derived from a carboxylic acid having an alicyclic structure.

15. 3. The toner of claim 1, wherein the toner particles comprise an ester wax.

16. 16. The toner according to claim 15, wherein the ester wax is a polyfunctional ester wax having two or more ester groups.

17. 16. The toner according to claim 15, wherein the ester wax is a bifunctional ester wax having two ester groups.

Images