toner

Abstract

The present invention relates to toner. The toner is toner including toner particles containing a binder resin, a crystalline material, wherein, when the toner is ruthenized under a specific condition (1), a proportion of an area occupied by the crystalline material in a surface of the toner observed by a scanning electron microscope is represented as S1 (%), when the toner is ruthenized under a condition (2), a proportion of an area occupied by the crystalline material in a surface of the toner observed by a scanning electron microscope is represented as S2 (%), and when the toner is ruthenized under the condition (2), a dispersion diameter of a plurality of domains formed of the crystalline material on a surface of the toner observed by a scanning electron microscope is represented as R2 (nm), the following formulas (1), (2), and (3) are satisfied. 0.0 ≤ S1 ≤ 0.5 (1) 1.0 ≤ S2 ≤ 10.0 (2) 20 ≤ R2 ≤ 200 (3)

Description

Technical Field

[0001] The present disclosure relates to a toner used in an image forming method such as electrophotography. Background Art

[0002] Electrophotography is a technology for forming an electrostatic latent image on a uniformly charged photosensitive member and visualizing the image information using charged toner. It is used in devices such as copiers and printers. In recent years, copiers and printers have been introduced into new market sectors, and as a result, they are required to stably provide high-quality images to meet various usage scenarios (e.g., usage environments and various media). Furthermore, from the perspectives of high-speed and energy-saving, there is a need for toners to further improve their low-temperature fixing properties.

[0003] Japanese Patent Application Publication No. 2017-003779 describes a toner in which the locations of crystalline resin present in the toner particle's center are defined relative to the surface. This reduces the number of crystalline resin domains in the fixed image, which can lead to reduced toughness. This allows for the provision of a toner capable of low-temperature fixation while suppressing a decrease in the image's bending strength.

[0004] Japanese Patent Application Publication No. 2016-126075 describes a toner having a shell layer formed from a thermosetting resin having a defined structure and a thermoplastic resin. By using an amino resin made from a melamine resin, a urea-formaldehyde resin, or a glyoxal resin as the thermosetting resin, a toner having excellent color development, heat-resistant storage stability, charging stability, and image density stability can be provided. Summary of the Invention

[0005] The toner described in Japanese Patent Application Publication No. 2017-003779 is effective in achieving both low-temperature fixability and powder flowability. However, it has been found that on media with large irregularities, significant differences in the plasticization of the toner due to the crystalline material between the convex and concave portions of the media can occur, resulting in image unevenness.

[0006] The toner described in Japanese Patent Application Publication No. 2016-126075 has excellent color development, heat-resistant storage stability, charging stability, and image density stability. However, it has been found that on media with large irregularities, significant differences in the plasticization of the toner due to the crystalline material between the convex and concave portions of the media can occur, resulting in uneven images caused by the toner.

[0007] For the reasons described above, the present disclosure provides a toner that is excellent in low-temperature fixability and significantly reduces image unevenness on a medium having large irregularities.

[0008] The present disclosure relates to a toner comprising toner particles containing a binder resin, a crystalline material, and a colorant, wherein when the ratio of the area occupied by the crystalline material to the surface area of ​​the toner on the surface of the toner observed by a scanning electron microscope (SEM) after the toner is stained with ruthenium under the following condition (1) is represented by S1 (%), the ratio of the area occupied by the crystalline material to the surface area of ​​the toner on the surface of the toner observed by a scanning electron microscope (SEM) after the toner is stained with ruthenium under the following condition (2) is represented by S2 (%), and the dispersion diameter of a plurality of domains formed by the crystalline material on the surface of the toner observed by a scanning electron microscope (SEM) after the toner is stained with ruthenium under the following condition (2) is represented by R2 (nm), the following formulas (1), (2), and (3) are satisfied:

[0009] 0.0≤S1≤0.5 (1)

[0010] 1.0≤S2≤10.0 (2)

[0011] 20≤R2≤200 (3)

[0012] Condition (1) includes treating the toner in a ruthenium tetroxide (RuO4) atmosphere at 100 Pa for 5 minutes, and condition (2) includes treating the toner in a ruthenium tetroxide (RuO4) atmosphere at 500 Pa for 15 minutes.

[0013] According to the present disclosure, a toner can be provided that is excellent in low-temperature fixability and significantly reduces image unevenness on a medium having large irregularities.

[0014] Further features of the present invention will become apparent from the following description of exemplary embodiments. DETAILED DESCRIPTION

[0015] Unless otherwise specified, the description “XX or more and YY or “XX to YY” expressing a numerical range means that the numerical range includes the lower limit value and the upper limit value as endpoints.

[0016] When a numerical range is described in a segmented manner, the upper limit and lower limit of each numerical range can be arbitrarily combined.

[0017] Hereinafter, the present disclosure will be described in detail.

[0018] Improvements in a toner's low-temperature fixability are significantly affected by the location, type, and amount of crystalline material within the toner. The closer the crystalline material is to the toner's surface, the more effectively the toner is plasticized by the heat of fixing. However, the presence of crystalline material on the toner's surface degrades the toner's fluidity. Therefore, forming a shell layer on a toner core containing crystalline particles is a known method for achieving both low-temperature fixability and fluidity.

[0019] When a shell layer is formed on a toner core containing a crystalline material, deterioration of the toner's fluidity can be suppressed before the toner is fixed. Furthermore, the crystalline material seeps to the surface during fixing to plasticize the binder resin on the surface, thereby enabling low-temperature fixability. However, it has been found that the toner may cause image unevenness on media with large irregularities (low smoothness).

[0020] When fixing toner on a medium with large uneven surfaces, significant heat and pressure can be applied to the toner in the convex areas, causing excessive crystalline material to ooze out and plasticize the binder resin. Consequently, the toner deforms significantly. Meanwhile, heat and pressure are less easily applied to the toner in the concave areas, suppressing the crystalline material from oozing out and thus the plasticization of the binder resin. Consequently, toner deformation is minimal. It is hypothesized that image unevenness is caused by differences in toner deformation during fixing between the convex and concave areas.

[0021] From the foregoing viewpoints, the inventors of the present invention considered that the problem of image unevenness occurring on a medium having large concavities and convexities could be solved if excessive oozing of the crystalline material on the convex portions of the medium could be suppressed.

[0022] The inventors of the present invention conducted extensive research and found that the problem of image unevenness on a medium with large unevenness can be solved by providing a large difference in the amount of crystalline resin between the outermost surface of the colorant (first surface area) and the vicinity of its surface (second surface area) and reducing the particle size of the crystalline resin near the surface.

[0023] Here, in the toner of the present disclosure, the outermost surface of the toner (first surface region) refers to the toner surface observed by SEM in the toner treated under condition (1), and the vicinity of the surface of the toner (second surface region) refers to the toner surface observed by SEM in the toner treated under condition (2).

[0024] Specifically, in the toner of the present disclosure, after the toner is ruthenium-stained by treating it in a ruthenium tetroxide atmosphere at 100 Pa for 5 minutes, on the surface of the toner observed by SEM, the ratio S1 (%) of the area occupied by the crystalline material relative to the surface area of ​​the toner is greater than 0.0 and less than 0.5. Although the details of the measurement will be described below, when the toner is stained in a ruthenium tetroxide atmosphere at low pressure, the crystalline material present on the outermost surface (first surface area) of the toner can be visualized. As a method for controlling the ratio S1 of the area occupied by the crystalline material, the control of the amount of the unreacted hydrophobic agent and the low molecular weight hydrophobic agent condensate, the toner core-shell structure, etc. described below is given.

[0025] In addition, in the toner of the present invention, after the toner is ruthenium-stained by treating it in a ruthenium tetroxide atmosphere at 500 Pa for 15 minutes, on the surface of the toner observed by SEM, the ratio S2 (%) of the area occupied by the crystalline material relative to the surface area of ​​the toner is 1.0 or more and 10.0 or less. When dyeing is carried out for a long time in a ruthenium tetroxide atmosphere at a higher pressure than the dyeing of the outermost surface of the toner, the crystalline material present in the vicinity of the surface of the toner (the second surface region) can be visualized. As a method for controlling the ratio S2 of the area occupied by the crystalline material, there are given the process described below of configuring a hydrophobic magnetic material having an affinity for the crystalline material near the surface, and an emulsion aggregation method comprising aggregating the emulsified crystalline material in multiple stages.

[0026] Furthermore, in the toner of the present disclosure, after the toner is ruthenium-stained by treating it in a ruthenium tetroxide atmosphere at 500 Pa for 15 minutes, on the toner surface observed by SEM, the crystalline material forms a plurality of domains, and the dispersion diameter R2 of the domain is greater than or equal to 20 (nm) and less than or equal to 200 (nm). Although the details of the measurement method are described below, the staining is carried out for a long time under high pressure in a ruthenium tetroxide atmosphere to visualize the crystalline material present near the surface of the toner (the second surface region), and the area circle equivalent diameter of each domain is averaged to calculate their dispersion diameters. As a process for controlling the dispersion diameter R2 of the domain, a process of configuring a hydrophobic magnetic material having an affinity for the crystalline material near the surface described below, and an emulsion aggregation method comprising aggregating the emulsified crystalline material in multiple steps are given.

[0027] A case is described in which the ratio of the area occupied by the crystalline material in the first surface region and the dispersion diameter of the domain in the second surface region satisfy the above range, and the ratio of the area occupied by the crystalline material in the second surface region does not satisfy the above range. In this case, the amount of crystalline material near the surface is small, and therefore, the crystalline material inside the toner surface participates in fixing compared to the crystalline material near the toner surface. Therefore, the crystalline material needs to seep out from the inside of the toner to the toner surface over a long distance. In addition, when the amount of crystalline material near the toner surface is large, the crystalline material near the toner surface is excessively deposited and the deformation of the toner is amplified. Therefore, in many cases, the deformation of the toner changes significantly with respect to the temperature and pressure during fixing, and the image unevenness on the medium with large unevenness is not alleviated.

[0028] Furthermore, a case is described in which the ratio of the area occupied by the crystalline material and the domain dispersion diameter in the second surface region meet the aforementioned ranges, while the ratio of the area occupied by the crystalline material in the first surface region does not meet the aforementioned ranges. In this case, the amount of crystalline material present on the outermost surface is excessive, deteriorating the fluidity of the toner and increasing uneven distribution of the toner on the medium. Consequently, image unevenness on a medium having large irregularities is not reduced.

[0029] Furthermore, a case is described in which the ratio of the areas occupied by the crystalline material in the first and second surface regions satisfies the aforementioned range, but the domain dispersion diameter in the second surface region does not. In this case, the uneven presence of the crystalline material near the toner surface increases. Consequently, during fixing, areas near the toner surface where the crystalline material is excessively deposited and areas where the binder resin is insufficiently plasticized appear. Consequently, image unevenness on media with large irregularities is not reduced.

[0030] At the same time, when both the ratio of the area occupied by the crystalline material in the first and second surface regions and the domain dispersion diameter meet the above ranges, the crystalline material near the surface is not excessively deposited even in convex and concave portions, and the binder resin on the surface is uniformly plasticized. Therefore, image unevenness on media with large concave and convex portions can be significantly suppressed for the first time.

[0031] In addition, when the ratio of the area occupied by the crystalline material in the first surface region falls within the above range, the fluidity is satisfactory to improve uneven distribution of the toner. The ratio is more preferably 0.0% or more and 0.3% or less.

[0032] Furthermore, when the ratio of the area occupied by the crystalline material in the second surface region falls within the above range, low-temperature fixing property is excellent and excessive bleeding can be suppressed. The ratio is more preferably 1.2% or more and 5.0% or less.

[0033] Furthermore, when the dispersion diameter of the domains in the second surface region falls within the above range, low-temperature fixability is excellent and image unevenness can be suppressed. The dispersion diameter is more preferably 40 nm or more and 150 nm or less.

[0034] Furthermore, in the toner of the present disclosure, preferably, the relationship between the dispersion diameter of the domain of the crystalline material present inside the toner particle and the dispersion diameter of the domain of the crystalline material present in the second surface region is controlled.

[0035] In the toner of the present disclosure, preferably, after a thin slice of the toner cut out with a microtome is stained with ruthenium by treatment in a ruthenium tetroxide atmosphere at 500 Pa, a plurality of internal domains are formed in a cross section of the toner observed by a transmission electron microscope (TEM), and the dispersion diameter R of the internal domains is preferably 0.05. i (nm) and the dispersion diameter R2 (nm) of the domains in the second surface region satisfy the following formula.

[0036] R i <R2

[0037] When the domains of crystalline material near the surface are larger than those within the toner, image unevenness in halftone images on media with large irregularities can be suppressed. Compared to solid images, halftone images have a lower toner load and are more susceptible to heat and pressure. Therefore, bleed-through from the internal domains is more likely to occur. It is conceivable that satisfying the above equation will suppress excessive bleed-through even in convex areas, thus minimizing image unevenness in halftone images on media with large irregularities.

[0038] There is no particular limitation on the crystalline material used in the toner of the present disclosure, and known materials can be used. The crystalline material refers to a material that exhibits a clear melting point in measurement using a differential scanning calorimeter (DSC).

[0039] In the toner of the present disclosure, from the viewpoint of low-temperature fixability and releasability, ester wax, hydrocarbon-based wax, or crystalline polyester resin may be used as the crystalline material.

[0040] In the toner of the present disclosure, the crystalline material preferably contains wax from the viewpoint of releasability, and more preferably contains ester wax from the viewpoint of low-temperature fixing ability.

[0041] Ester waxes are waxes containing fatty acid esters as their main component. Preferred ester waxes are described below. The functional number described below indicates the number of ester groups contained in one molecule. For example, behenyl behenate is considered a "monofunctional ester wax," while dipentaerythritol hexabehenate is considered a "hexafunctional ester wax."

[0042] As the monofunctional ester wax, a condensate of an aliphatic alcohol and an aliphatic carboxylic acid is preferred. In this case, the aliphatic carbon number is preferably 6 to 26.

[0043] Examples of the aliphatic alcohol include 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, undecanol, and lauryl alcohol. In addition, examples of the aliphatic carboxylic acid include valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, and decanoic acid.

[0044] A combination of a dicarboxylic acid and a monoalcohol, or a combination of a diol and a monocarboxylic acid can be used as the difunctional ester wax.

[0045] Examples of dicarboxylic acids include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanoic acid.

[0046] Examples of the diol include 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0047] The monoalcohol condensed with the dicarboxylic acid is preferably an aliphatic alcohol. Specific examples thereof include tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, arachidyl alcohol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, and octacosanol. Among them, docosanol is preferred from the viewpoint of fixability and developability.

[0048] The monocarboxylic acid condensed with the diol is preferably an aliphatic carboxylic acid. Specific examples thereof include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, tuberculostearic acid, arachidic acid, behenic acid, lignoceric acid, and cerotic acid as fatty acids. Among them, stearic acid and behenic acid are preferred from the viewpoint of fixability and developability.

[0049] Although straight-chain fatty acids and straight-chain alcohols have been exemplified herein, these acids and alcohols each may have a branched structure.

[0050] Hereinafter, the crystalline polyester resin is described. There is no particular limitation on the crystalline polyester resin, and known resins can be used. However, saturated polyester is preferred.

[0051] Furthermore, the crystalline polyester resin is preferably a condensate of an aliphatic dicarboxylic acid, an aliphatic diol, and an aliphatic monocarboxylic acid and / or an aliphatic monoalcohol. More preferably, the crystalline polyester resin is a condensate of an aliphatic dicarboxylic acid, an aliphatic diol, and an aliphatic monocarboxylic acid. Incorporating an aliphatic monocarboxylic acid and / or an aliphatic monoalcohol as a constituent component of the crystalline polyester resin facilitates adjustment of the molecular weight and hydroxyl value of the crystalline polyester resin.

[0052] Examples of monomers that can be used are given below.

[0053] Examples of the aliphatic diacids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, hexadecanedioic acid, and octadecanedioic acid.

[0054] Examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, trimethylene glycol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,16-hexadecanediol, and 1,18-octadecanediol.

[0055] Examples of aliphatic monocarboxylic acids include n-decanoic acid (capric acid), dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), eicosanoic acid (arachidic acid), behenic acid (behenic acid), and tetracosanoic acid (lignoceric acid).

[0056] Examples of the fatty monoalcohols include lauryl alcohol, stearyl alcohol, and behenyl alcohol.

[0057] By using such a monocarboxylic acid and a monoalcohol, a crystalline polyester resin having an alkyl group (preferably having 2 or more and 24 or less carbon atoms) at the terminal can be obtained.

[0058] Herein, the monocarboxylic acid has only one carboxylic acid, and therefore, a structure derived from the monocarboxylic acid is located at the terminal of the molecular chain of the crystalline polyester resin.

[0059] The weight average molecular weight Mw of the crystalline polyester resin is preferably 5,000 or more and 60,000 or less.

[0060] Crystalline polyester resins can be produced by conventional polyester synthesis methods. For example, crystalline polyester resins can be obtained by subjecting a dicarboxylic acid component and a diol component to an esterification reaction or an ester exchange reaction, followed by a polycondensation reaction under reduced pressure or with the introduction of nitrogen according to a conventional method.

[0061] The hydrocarbon wax is an aliphatic hydrocarbon wax, and examples thereof include low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, Fischer-Tropsch wax, paraffin wax, and polyolefin wax.

[0062] In the toner of the present disclosure, the above-mentioned two materials may be used in combination as the crystalline material. Hereinafter, each material is sometimes referred to as a "first crystalline material" and a "second crystalline material."

[0063] The content of the crystalline material is preferably 2 parts by mass or more and 30 parts by mass or less, more preferably 4 parts by mass or more and 25 parts by mass or less, still more preferably 10 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the binder resin.

[0064] The melting point of the crystalline material is preferably 60°C or higher and 90°C or lower, more preferably 65°C or higher and 80°C or lower.

[0065] Hereinafter, the colorant used for the toner of the present disclosure is described.

[0066] In the present disclosure, the colorant is preferably treated with a silane coupling agent for hydrophobization. When the colorant is treated with a silane coupling agent for hydrophobization, the dispersibility of the colorant in the toner is improved, and the hydrophobized colorant has a high affinity for crystalline materials. Therefore, the dispersion diameters of the domains in the second surface region of the toner and the domains within the toner can be easily controlled to a preferred range. The silane coupling agent used for the silane coupling treatment is represented by the following formula.

[0067] R-SiX n Y m

[0068] In the formula, X and Y each represent an alkoxy group, "n" and "m" each represent an integer from 0 to 3, and n+m=3, and R represents a functional group such as an alkyl group, a phenyl group, a vinyl group, an epoxy group, or a (meth)acrylic group.

[0069] Examples of the silane coupling agent represented by the above formula include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxyethoxy)silane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethylsilane, Silane coupling agents include phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-propyltrimethoxysilane, isopropyltrimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, trimethylmethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, hydroxypropyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane. In the present invention, silane coupling agents in which each R in the above formula is an alkyl group can be preferably used. Among them, silane coupling agents having an alkyl group of 3 or more and 6 or less carbon atoms are preferred, and silane coupling agents having an alkyl group of 3 or 4 carbon atoms are particularly preferred.

[0070] When the above silane coupling agents are used, the treatment can be performed using one silane coupling agent or a combination of multiple silane coupling agents. When multiple silane coupling agents are used in combination, the treatment can be performed using each coupling agent alone, or multiple silane coupling agents can be used simultaneously.

[0071] As the colorant, the following organic pigments, organic dyes, and inorganic pigments are given.

[0072] As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds are given.

[0073] Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

[0074] As the black colorant, carbon black and those toned to black by using the above-mentioned yellow colorant, magenta colorant, cyan colorant, and magnetic powder are given.

[0075] In the present disclosure, the colorant is preferably a hydrophobized magnetic material. When the colorant is a hydrophobized magnetic material, the hydrophobized magnetic material may be present near the surface of the toner in the suspension polymerization method, which is a production method suitable for the present disclosure. Therefore, in the suspension polymerization method, the ratio of the area occupied by the crystalline material in the second surface region can be easily controlled.

[0076] In the present disclosure, preferably, the peak intensity ratio [Si-O-Si] / [Si-C] of the ATR-IR of the component extracted from the hydrophobized magnetic material with toluene is 1.4 to 2.5. The peak intensity ratio of ATR-IR affects the unreacted treatment agent and low molecular weight treatment agent condensate contained in the hydrophobized magnetic material. In addition, the unreacted treatment agent and the treatment agent condensate have a high affinity for crystalline material and water, and act as the crystal nucleus of the crystalline material. When the peak intensity ratio falls within the above range, the amount of unreacted treatment agent and the treatment agent condensate is small, so its release to the toner surface is suppressed. Therefore, it is easy to control the ratio of the area occupied by the crystalline material in the first surface region to a preferred range.

[0077] In the present disclosure, preferably, the presence index near the surface of the hydrophobized magnetic material obtained by observing the toner by SEM is 4.0 to 8.0 pieces / 1 μm. 2 The coefficient of magnetic material near the surface is the number of magnetic materials present near the surface of the toner particles, that is, per 1 μm 2 The number of surface areas.

[0078] The index falls between 4.0 and 8.0 per 1 μm 2 The range of means that the magnetic material is unevenly distributed near the surface of the toner particles. Therefore, even on the convex portion of the medium, deformation of the toner is suppressed, thereby suppressing image unevenness on a medium with large concave and convex (low smoothness).

[0079] This index can be controlled by the dispersion intensity in the dispersion step of the magnetic material. When the dispersion intensity increases, the magnetic material is broken up and can be dispersed in the toner as primary particles.

[0080] Furthermore, in order to improve the index, a process for increasing the fraction of the magnetic material may be combined.

[0081] The amount of the magnetic material added is preferably 40 parts by mass or more and 200 parts by mass or less, and more preferably 60 parts by mass or more and 120 parts by mass or less, relative to 100 parts by mass of the binder resin.

[0082] In the present disclosure, the hydrophobized magnetic material preferably has a hydrophobicity of 55 to 80. When the hydrophobicity falls within this range, the hydrophobized magnetic material can be present in a dispersed state near the toner surface in the suspension polymerization method, which is a production method suitable for the present disclosure. Therefore, in the suspension polymerization method, it is easy to control the ratio of the area occupied by the crystalline material in the second surface region and the dispersed diameter of the domains to within the preferred range.

[0083] In the present disclosure, it is preferred that the value of (mass change rate / specific surface area) is 0.002 to 0.020%·g / m 2 This value is obtained by dividing the mass change rate of the hydrophobized magnetic material by the specific surface area of ​​the hydrophobized magnetic material when the hydrophobized magnetic material is allowed to stand in an environment with a temperature of 30°C and a relative humidity of 0% for 24 hours, and then in an environment with a temperature of 30°C and a relative humidity of 80% for 1 hour. When the ratio "mass change rate / specific surface area" falls within the above range, the affinity for the ester wax preferred in the present disclosure is improved. Therefore, the dispersion diameter of the domains in the second surface region of the toner and the domains within the toner can be easily controlled to the preferred range.

[0084] In the present disclosure, preferably, in the hydrophobized magnetic material, a spectrum of Si obtained based on a total electron yield (TEY) method using near-edge X-ray absorption fine structure (NEXAFS) has a peak A in the range of 1,844.4 to 1,844.8 eV and a peak B in the range of 1,846.1 to 1,846.6 eV, and when the area of ​​peak A is divided by 1 A The area of ​​peak B is represented by I B The number of moles of Si derived from the silane compound contained in 1 g of the hydrophobized magnetic material is represented by M Si When I A / (I A +I B ) / M Si 40 to 55.

[0085] NEXAFS can provide information about the state of the silane compound bonded to the Fe atoms in the magnetic material. It can be determined that the larger Peak A in the Si absorption spectrum, the smaller the amount of silane compound bonded to the surface of the magnetic material. Conversely, the larger Peak B, the larger the amount of silane compound bonded to the surface of the magnetic material.

[0086] The bonding degree between the surface of silane compound and magnetic material is important. When the ratio of the silane compound chemically bonded to the surface of magnetic material is smaller, the molecules of silane coupling agent condense with each other at a higher degree, and the silane compound on the surface of magnetic material becomes bulky. When the silane coupling compound is large, the affinity for crystalline material becomes higher to attract crystalline material and accelerate the growth of domain. Therefore, the ratio of the area occupied by crystalline material in the second surface region and the dispersion diameter of domain can be easily controlled to a preferred range.

[0087] Where, I A represents the area of ​​peak A, I B represents the area of ​​peak B, M Si represents the number of moles of Si derived from the silane compound contained in 1 g of the hydrophobized magnetic material.

[0088] Specifically, it is important that the value obtained by dividing the intensity of peak A representing the bond between molecules of the silane coupling agent by the number of moles of Si derived from the silane compound subjected to surface treatment and peak A and peak B falls within the above range. When the value of the above formula is greater than 55, the bond between the silane compound and the magnetic material in the bonded state is weakened, thereby exposing the hydrophilic magnetic material, and as a result, the function of the silane compound cannot be effectively demonstrated. At the same time, when the value of the above formula is less than 40, the surface of the magnetic material is bonded to the silane compound, but the silane compound does not have a large structure, and as a result, the function cannot be effectively demonstrated. From the above viewpoint, the value of the above formula falls within the range of preferably 40 to 55, more preferably 43 to 48. A / (I A +I B ) divided by M Si The reason for the value of is normalization.

[0089] High I A / (I A +I B ) / M Si The value of (hereinafter sometimes referred to as " NEXAFS value ") shows that in the hydrophobic agent, the amount of condensation between the molecules of the treating agent relative to the amount of the treating agent bonded to the magnetic material is larger. The compound to which the hydrophobic agent is subjected to polycondensation has a very high hydrophobicity, and therefore easily improves the affinity for crystalline materials. Therefore, a large amount of crystalline materials may be present in the vicinity of the magnetic material. Therefore, in the suspension polymerization method as a production method applicable to the present invention, the hydrophobized magnetic material may be present near the surface of the toner. Therefore, in the suspension polymerization method, it is easy to control the amount of crystalline materials present near the toner surface.

[0090] The magnetic material according to the present disclosure contains a magnetic iron oxide such as ferroferric oxide or γ-iron oxide as a main component, and may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, and silicon. The BET specific surface area of ​​each of these magnetic materials by nitrogen adsorption is preferably 2 m 2 / g to 30m 2 / g, more preferably 3m 2 / g to 28m 2 / g. In addition, those each having a Mohs hardness of 5 to 7 are preferred. Examples of the shape of the magnetic material include polyhedron, octahedron, hexahedron, sphere, needle, and scale, and from the viewpoint of increasing image density, those having small anisotropy such as polyhedron, octahedron, hexahedron, and sphere are preferred.

[0091] Preferably, the magnetic material has a number average primary particle size of 0.10 μm or more and 0.40 μm or less. Generally, when the particle size of the magnetic material is smaller, the tinting power of the toner increases. However, the magnetic material is easy to aggregate, and the uniform dispersibility of the magnetic powder in the toner becomes poor. Therefore, a smaller particle size is not preferred. In addition, when the number average primary particle size is less than 0.10 μm, the magnetic material itself becomes reddish black, and the reddish color is particularly noticeable in the halftone image. It cannot be said that the image has high quality. Therefore, it is not preferred that the number average primary particle size is less than 0.10 μm. At the same time, when the number average primary particle size is greater than 0.40 μm, the tinting power of the toner is insufficient, and in the suspension polymerization method (described below) which is a toner production method suitable for the present disclosure, uniform dispersion becomes difficult. Therefore, it is not preferred that the number average primary particle size is greater than 0.40 μm.

[0092] The number average primary particle size of the magnetic material can be measured using a transmission electron microscope (TEM). Specifically, the toner particles to be observed are fully dispersed in an epoxy resin, and the resultant is cured for 2 days in an atmosphere at a temperature of 40°C to obtain a cured product. The cured product thus obtained is formed into a thin sample using a microtome, and the particle size of 100 magnetic powder particles in the field of view of the photograph is measured using a transmission electron microscope (TEM) at a magnification of 10,000 to 40,000 times. The number average primary particle size is then calculated based on the circle equivalent diameter equal to the projected area of ​​the magnetic material. In addition, the number average primary particle size can also be measured using an image analyzer.

[0093] The magnetic material used in the toner of the present disclosure can be produced, for example, by the following method. An alkali such as sodium hydroxide is added to an aqueous ferrous salt solution in an amount equal to or greater than that of the iron component, thereby preparing an aqueous solution containing ferrous hydroxide. Air is blown into the prepared aqueous solution while maintaining the pH of the solution at or above pH 7, while the aqueous solution is heated to or above 70° C., thereby oxidizing the ferrous hydroxide to initially generate seed crystals serving as cores of the magnetic material.

[0094] Then, based on the addition of the alkali added in advance, the aqueous solution containing about 1 equivalent of ferrous sulfate is added to the paste-like liquid containing seed crystal. Under the condition that the pH value of liquid is maintained at 5 to 10, carry out the reaction of ferrous hydroxide when blowing air into the liquid.Thus, using seed crystal as nuclear magnetic material growth.In this case, the shape and magnetic properties of magnetic material can be controlled by selecting any pH value, reaction temperature and stirring condition.Along with carrying out oxidation reaction, the pH value of liquid is transferred to the acidic side, but preferably, the pH value of liquid is not less than 5.Filter, wash and dry the magnetic material thus obtained by conventional method.Thus, magnetic material can be obtained.

[0095] The following can be used as the binder resin for the toner of the present disclosure: homopolymers of styrene and its substitution products such as polystyrene and polyvinyltoluene, styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-butyl acrylate copolymers, styrene-octyl acrylate copolymers, styrene-dimethylaminoethyl acrylate copolymers, styrene-methyl methacrylate copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-dimethylaminoethyl methacrylate copolymers, styrene-vinyl methyl ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers; and styrene-methyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resins, polyester resins, polyamide resins, epoxy resins, and polyacrylic resins. These binder resins can be used alone or in combination. Among them, styrene acrylic resins represented by styrene-butyl acrylate copolymers are particularly preferred from the viewpoints of, for example, developing characteristics and fixing properties.

[0096] The toner of the present invention may use a charge control agent to stabilize the chargeability of the toner regardless of the environment.

[0097] As negatively chargeable charge control agents, the following are given: monoazo metal compounds, acetylacetonate metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, metal compounds based on oxycarboxylic acids and dicarboxylic acids, aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids and polycarboxylic acids, and metal salts, anhydrides, and esters thereof, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, boron compounds, quaternary ammonium salts, calixarenes, and resin-based charge control agents.

[0098] As positively chargeable charge control agents, the following are given: products based on nigrosine modification such as nigrosine and fatty acid metal salts; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthalenesulfonate and tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts as analogs thereof, and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (for example, as fixing agents, phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferrocyanide, and ferrocyanide); higher fatty acid metal salts; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate, and dicyclohexyltin borate; and resin-based charge control agents.

[0099] These charge control agents may be used alone or in combination.

[0100] Among them, as a charge control agent other than the resin-based charge control agent, a metal-containing salicylic acid-based compound is preferred, and specifically, a metal-containing salicylic acid-based compound containing aluminum or zirconium as a metal is preferred. A particularly preferred control agent is an aluminum salicylate compound.

[0101] A polymer or copolymer having a sulfonic acid group, a sulfonate group, a sulfonate group, a salicylic acid moiety, or a benzoic acid moiety is preferably used as the resin-based charge control agent.

[0102] The blending amount of the charge control agent is preferably 0.01 parts by mass to 20.0 parts by mass, more preferably 0.05 parts by mass to 10.0 parts by mass with respect to 10.0 parts by mass of the polymerizable monomer.

[0103] (Toner Production Method)

[0104] The toner of the present disclosure can be produced by any known method. First, for example, when the toner is produced by a pulverization method, a binder resin, a colorant, a wax, and, as required, components required for the toner such as a charge control agent, and other additives are fully mixed using a mixer such as a Henschel mixer or a ball mill. Then, the mixture is melt-kneaded using a heating kneader such as a heated roller, a kneader, or an extruder to disperse or dissolve the toner material, and the mixture is cooled and solidified, pulverized, and then classified, and surface treated as required. Thus, toner particles can be obtained. Either classification or surface treatment can be performed first. In the classification step, from the perspective of production efficiency, a multi-stage classifier is preferably used.

[0105] The pulverization step can be performed by using a known pulverization device such as a mechanical impact pulverization device or a jet pulverization device to control the state of the crystalline material of the present invention. In addition, preferably, heat is further applied to pulverize the mixture or a process of applying auxiliary mechanical impact is performed. In addition, a hot water bath method involving dispersing finely pulverized (if necessary, classified) toner particles in hot water or a method involving passing toner particles through a hot air flow can be used.

[0106] As a method of applying mechanical impact force, for example, a method using a mechanical impact pulverizer such as the Cryptron System manufactured by Kawasaki Heavy Industries, Ltd. or the Turbo Mill manufactured by Freund-Turbo Corporation is given. In addition, devices such as the Mechanofusion System manufactured by Hosokawa Micron Corporation and the Hybridization System manufactured by Nara Machinery Co., Ltd. can also be used. In the process of producing toner particles, each of these devices presses the pulverized material against the inside of a housing using centrifugal force using a blade rotating at high speed, and applies mechanical impact force such as compression force and friction force to pulverize the material.

[0107] When the toner of the present disclosure is produced by a pulverization method, the toner can also be changed into toner particles each having a core-shell structure.

[0108] The toner of the present disclosure can also be produced by the pulverization method described above, but the toner of the present disclosure has a structure in which a specific amount of crystalline material is present near the toner surface, and almost no crystalline material is present on the outermost surface of the toner. Therefore, the toner is preferably produced in an aqueous medium.

[0109] When producing toner using an emulsion aggregation method, when a crystalline material aggregates to expose itself on the toner surface and then an amorphous resin having a large SP value difference from the crystalline material is used, there is a problem of easily inhibiting shell formation. To address this issue, a small amount of an amorphous resin having a relatively small SP value difference from the crystalline material is aggregated on the toner surface, and then another amorphous resin having a relatively large SP value difference is used to form a shell. This results in the toner of the present invention.

[0110] Hereinafter, the suspension polymerization method is described.

[0111] Suspension polymerization involves uniformly dissolving or dispersing a polymerizable monomer and a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives) to obtain a polymerizable monomer composition, then dispersing the polymerizable monomer composition in a continuous layer (e.g., an aqueous phase) containing a dispersant using a suitable agitator while simultaneously allowing a polymerization reaction to proceed, thereby obtaining a toner having a desired particle size. The toner obtained by suspension polymerization (hereinafter sometimes referred to as "polymerized toner") contains toner particles each having a substantially spherical shape, and therefore, the distribution of the charge amount is relatively uniform. Therefore, improvement in image quality can be expected.

[0112] In the production of the polymerized toner according to the present disclosure, as polymerizable monomers for forming the polymerizable monomer composition, the following are given.

[0113] Examples of polymerizable monomers include: styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; acrylates such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate; methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate; and other monomers such as acrylonitrile, methacrylonitrile, and acrylamide. These monomers can be used alone or in mixtures. Among the above monomers, styrene is preferably used alone or in mixtures with any other monomers from the viewpoint of the developing properties and durability of the toner.

[0114] The polymerization initiator used to produce the toner of the present disclosure by a polymerization method preferably has a half-life during the polymerization reaction of 0.5 hours to 30 hours. Furthermore, when the polymerization reaction is carried out using the polymerization initiator in an amount of 0.5 parts by mass to 20 parts by mass per 100 parts by mass of the polymerizable monomer, a polymer having a maximum molecular weight within the range of 5,000 to 50,000 is obtained, and the toner can be provided with desired strength and suitable melting characteristics.

[0115] Specific examples of the polymerization initiator include: azo-based or diazo-based polymerization initiators such as 2,2′-azobis-(2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis(cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile; and peroxide-based polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butyl peroxy-2-ethylhexanoate, and t-butyl peroxypivalate.

[0116] When the toner of the present disclosure is produced by a polymerization method, a crosslinking agent may be added, and its preferred addition amount is 0.001 parts by mass or more and 15 parts by mass or less relative to 100 parts by mass of the polymerizable monomer.

[0117] Herein, compounds having two or more polymerizable double bonds are mainly used as crosslinking agents, and the following are used alone or as a combination thereof: for example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene, for example, carboxylates each having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate, divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, and divinyl sulfone, and compounds each having three or more vinyl groups.

[0118] In the method for producing the toner of the present disclosure by polymerization, a polymerizable monomer composition obtained by appropriately adding the above-mentioned polymerizable monomer and colorant and uniformly dissolving or dispersing the materials by a disperser such as a homogenizer, a ball mill, or an ultrasonic disperser is usually suspended in an aqueous medium containing a dispersant. In this case, when a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser is used to set each toner particle to the desired toner particle size at one time, the particle size of each toner particle to be obtained becomes sharper. Regarding the timing of adding the polymerization initiator, the polymerization initiator can be added at the same time as other additives are added to the polymerizable monomer, or can be mixed immediately before being suspended in the aqueous medium. In addition, the polymerizable monomer or the polymerization initiator dissolved in the solvent can be added immediately after granulation and before the polymerization reaction begins.

[0119] After granulation, stirring may be performed using a conventional stirrer to such an extent that the state of the particles is maintained and the floating and sedimentation of the particles are prevented.

[0120] When producing the toner of the present invention, known surfactants, organic dispersants, or inorganic dispersants can be used as dispersants. Among them, inorganic dispersants are less likely to produce harmful ultrafine powders. Inorganic dispersants have dispersion stability due to their steric hindrance, and therefore are less likely to lose stability even when the reaction temperature is changed. Inorganic dispersants are easy to wash off and have almost no adverse effect on the toner. Therefore, inorganic dispersants can be preferably used. Examples of such inorganic dispersants include: polyvalent metal salts of phosphoric acid such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and hydroxyapatite; carbonates such as calcium carbonate and magnesium carbonate; inorganic salts such as calcium metasilicate, calcium sulfate, and barium sulfate; and inorganic compounds such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide.

[0121] Desirably, each of these inorganic dispersants is used in an amount of 0.2 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of the polymerizable monomer. Furthermore, the inorganic dispersants may be used alone or in combination. Furthermore, surfactants may be used in an amount of 0.001 parts by mass or more and 0.1 parts by mass or less.

[0122] When using inorganic dispersants, they can be used as is. However, to obtain finer particles, inorganic dispersant particles produced in an aqueous medium can be used. For example, in the case of tricalcium phosphate, water-insoluble calcium phosphate can be produced by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring, thereby enabling a more uniform and finer dispersion. In this case, a water-soluble sodium chloride salt is also produced as a byproduct. Furthermore, since the dissolution of the polymerizable monomer in water is suppressed, the presence of a water-soluble salt in the aqueous medium makes it difficult to produce ultrafine toners through emulsion polymerization.

[0123] Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, and potassium stearate.

[0124] In the step of polymerizing the polymerizable monomer, the polymerization temperature is set to 40° C. or higher, usually 50° C. or higher and 90° C. or lower.

[0125] Toner particles are obtained by filtering, washing, and drying the polymer particles thus obtained using known methods. If necessary, an inorganic fine powder, described below, is mixed with the toner particles to cause adhesion to the surface of each toner particle. Thus, the toner of the present invention can be obtained. Furthermore, a classification step can be inserted into the production process (before mixing the inorganic fine powder) to discard coarse and fine powders contained in the toner particles.

[0126] The toner of the present disclosure is prepared as a toner by mixing additives such as a fluidizer as needed with the toner particles obtained by the production method described above. For the mixing method, a known method can be used, and for example, a Henschel mixer is an apparatus that can be appropriately used.

[0127] In the toner disclosed herein, an inorganic fine powder having a number average primary particle size of 4 to 80 nm, more preferably 6 to 40 nm, is preferably added to the toner particles as a fluidizing agent. The inorganic fine powder is added to improve the toner's fluidity and to uniformize the charge of the toner particles. Furthermore, the inorganic fine powder is preferably treated, for example, with hydrophobization, to impart functions such as adjusting the toner's charge and improving its environmental stability. The number average primary particle size of the inorganic fine powder is measured using magnified photographs taken with a scanning electron microscope.

[0128] Silica, titanium oxide, or aluminum oxide can be used as the inorganic fine powder used in the present disclosure. For example, dry silica produced by vapor-phase oxidation of silicon halide or dry silica called fumed silica, and wet silica produced from water glass or the like can each be used as the silica fine powder. However, it is preferred that the silica fine powder have a small number of silanol groups and, for example, Na2O and SO3 on the surface and inside. 2- Dry silica with less residue can be produced by, for example, using any other metal halogen compound such as aluminum chloride or titanium chloride together with the silicon halogen compound in the production process. Composite fine powders of silica and any other metal oxide can also be obtained, and the inorganic fine powder also includes the composite fine powder.

[0129] The amount of inorganic fine powder added, having a number average primary particle size of 4 nm to 80 nm, is preferably 0.1% to 3.0% by mass relative to the toner particles. If the amount added is less than 0.1% by mass, the effect of the inorganic fine powder is insufficient. If the amount added exceeds 3.0% by mass, the toner's fixing properties deteriorate. The content of the inorganic fine powder can be determined using a calibration curve created from standard samples using fluorescent X-ray analysis.

[0130] In the present disclosure, the inorganic fine powder is preferably a hydrophobizing substance because it can improve the environmental stability of the toner. When the inorganic fine powder added to the toner absorbs moisture, the charge of the toner particles is significantly reduced and tends to be non-uniform, resulting in the toner being prone to scattering. For example, treatment agents such as silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds can be used alone or in combination as treatment agents for the hydrophobizing treatment of the inorganic fine powder.

[0131] In the toner of the present disclosure, other additives may be further used in small amounts as developability improvers, as long as they do not substantially adversely affect the toner, such as lubricant powders such as fluororesin powder, zinc stearate powder, or polyvinylidene fluoride powder, polishing agents such as cerium oxide powder, silicon carbide powder, or strontium titanate powder, fluidity-imparting agents such as titanium oxide powder or aluminum oxide powder, anti-caking agents, or organic fine particles and inorganic fine particles having opposite polarities. These additives may be used after their surfaces have been subjected to a hydrophobic treatment.

[0132] The weight average particle size (D4) of the toner produced by the present disclosure is preferably 3.0 μm or more and 12.0 μm or less, more preferably 4.0 μm or more and 10.0 μm or less. When the weight average particle size (D4) is 3.0 μm or more and 12.0 μm or less, satisfactory fluidity is obtained and a latent image can be faithfully developed.

[0133] The following describes the measurement methods of various physical properties.

[0134] <Method for measuring hydrophobicity>

[0135] The hydrophobicity was determined using a powder wettability tester WET-100P manufactured by Rhesca Co., Ltd. and a methanol droplet permeability curve measured under the following conditions and procedures.

[0136] First, 50 ml of a methanol / water mixture (methanol concentration: 0%) was added to a flask, and its transmittance was measured. The transmittance at this point was set to 100%, and the transmittance when the mixture did not transmit light was set to 0%. Specifically, the mass percentage of methanol at which the transmitted light intensity during measurement reached half the transmitted light intensity when light passed through the methanol / water mixture (methanol concentration: 0%) was defined as the hydrophobicity of the present disclosure.

[0137] The transmittance was measured as follows.

[0138] A magnetic stirrer is placed in a beaker containing 50 ml of a methanol / water mixed solvent (methanol concentration: 0%). Then, 0.1 g of iron oxide particles screened through a sieve with a mesh size of 100 μm are accurately weighed and loaded into the above-mentioned flask. Then, stirring is started by a magnetic stirrer at a stirring speed of 300 rpm (5 revs / sec), and methanol is continuously added to the measurement sample solution at an addition rate of 1.3 ml / min using a glass tube. The transmittance of the liquid for light of a wavelength of 780 nm is measured, and a methanol drop transmittance curve is created. In this case, methanol is used as a titration solvent because the effect of the elution of the hydrophobic agent used for the surface treatment of the iron oxide particles is small, and therefore the surface properties of the iron oxide particles can be more accurately evaluated.

[0139] In this measurement, a glass beaker having a diameter of 5 cm was used as the beaker, and a magnetic stirrer having a spindle shape having a length of 25 mm and a maximum diameter of 8 mm and having a Teflon (trademark) coating applied thereon was used as the magnetic stirrer.

[0140] <Measurement of Weight Average Particle Diameter (D4) of Toner (Particles)>

[0141] The weight-average particle diameter (D4) of the toner (particles) is measured by using a precision particle size distribution measuring apparatus "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.) including a 100 μm orifice tube and based on a pore resistance method, and attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.) for setting measurement conditions and analyzing measurement data, with 25,000 effective measurement channels. Then, the measurement data is analyzed to calculate the particle diameter.

[0142] An electrolyte aqueous solution prepared by dissolving special grade sodium chloride in ion exchange water to have a concentration of about 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter, Inc.), can be used for the measurement.

[0143] Before performing measurement and analysis, set up the dedicated software as follows.

[0144] On the "Change Standard Measurement Method (SOM)" screen of the dedicated software, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the value obtained by using "standard particles each having a particle size of 10.0 μm" (manufactured by Beckman Coulter, Inc.) as the Kd value. Pressing the Threshold / Noise Level Measurement button automatically sets the threshold and noise level. Also, set the current to 1,600 μA, the gain to 2, and the electrolyte solution to ISOTON II. Place a check mark in the checkbox for whether to flush the orifice tube after measurement.

[0145] On the "Pulse to Particle Size Conversion Settings" screen of the dedicated software, set the element spacing to logarithmic particle size, set the particle size element to 256, and set the particle size range to 2 μm or more and 60 μm or less.

[0146] The specific measurement method is described as follows.

[0147] (1) Place approximately 200 ml of the electrolyte aqueous solution in a 250 ml glass round-bottom beaker dedicated to the Multisizer 3. Place the beaker on the sample stage and stir with a stirring rod in a counterclockwise direction at 24 rpm. Remove any dirt and bubbles from the nozzle using the "Nozzle Rinse" function in the dedicated software.

[0148] (2) About 30 ml of the electrolyte aqueous solution was placed in a 100 ml glass flat-bottom beaker. About 0.3 ml of a dilution solution prepared by diluting "Contaminon N" (a 10% by mass aqueous solution of a neutral detergent for washing precision measuring instruments composed of a nonionic surfactant, an anionic surfactant, and an organic builder, with a pH of 7, manufactured by Wako Pure Chemical Industries, Ltd.) with ion-exchanged water was added to the electrolyte aqueous solution as a dispersant.

[0149] (3) A predetermined amount of ion-exchanged water was placed in the water tank of an ultrasonic dispersing unit "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.) having a power output of 120 W and equipped with two oscillators each having an oscillation frequency of 50 kHz and a phase difference of 180°. Approximately 2 ml of Contaminon N was added to the water tank.

[0150] (4) Place the beaker in section (2) in the beaker fixing hole of the ultrasonic dispersing unit and operate the ultrasonic dispersing unit. Then, adjust the height of the beaker so that the liquid level of the aqueous electrolyte solution in the beaker can resonate with the ultrasonic waves from the ultrasonic dispersing unit to the greatest extent possible.

[0151] (5) While the electrolyte aqueous solution is being irradiated with ultrasonic waves, approximately 10 mg of the toner (particles) is gradually added to the electrolyte aqueous solution in the beaker in section (4) and dispersed. The ultrasonic dispersion treatment is then continued for an additional 60 seconds. During the ultrasonic dispersion, the temperature of the water in the water tank is appropriately adjusted to 10°C or higher and 40°C or lower.

[0152] (6) Using a pipette, the aqueous electrolyte solution in section (5) in which the toner (particles) are dispersed is dropped into the round-bottom beaker in section (1) placed on the sample stage, and the concentration of the toner to be measured is adjusted to approximately 5%. Then, measurement is performed until the particle diameters of 50,000 particles are measured.

[0153] (7) Use the dedicated software included with the instrument to analyze the measurement data and calculate the weight-average particle size (D4). When the dedicated software is set to display images in vol%, the "Average Diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" screen of the dedicated software is the weight-average particle size (D4).

[0154] <Method for measuring the number average particle size of magnetic materials>

[0155] The magnetic material to be observed is fully dispersed in an epoxy resin and then cured for 2 days in an atmosphere at a temperature of 40°C to obtain a cured product. The cured product thus obtained is formed into a thin sample with a microtome, and a cross-sectional image is taken at a magnification of 40,000 times using a transmission electron microscope (TEM). The particle size of 100 magnetic materials in the cross-sectional image is measured. Then, the number average particle size of the magnetic material is calculated based on the area circle equivalent diameter of the magnetic material.

[0156] <Calculation Method of the Area Ratio Occupied by the Crystalline Material in the First Surface Region of the Toner>

[0157] A vacuum electron staining apparatus (Filgen, Inc., VSC4R1H) is used to calculate the ratio S1 (%) of the area occupied by the crystalline material on the outermost surface (first surface area) of the toner relative to the area of ​​the toner surface. The calculation is performed using an image obtained by observing a reflected electron image of a toner stained in a RuO4 atmosphere at 100 Pa for 5 minutes using a field emission scanning electron microscope (sometimes referred to as a "scanning electron microscope" or "SEM") S-4800 (Hitachi High-Technologies Corporation). Liquid nitrogen is injected into the anti-fouling trap mounted on the housing of the S-4800 until the liquid nitrogen overflows, and then left for 30 minutes. The "PC-SEM" of the S-4800 is activated for flushing (washing the FE chip serving as the electron source). Click the acceleration voltage display portion of the control panel on the interface of the S-4800 and press its [Flush] button to open the flushing execution dialog box. Recognize the fact that the flushing intensity is 2 and flushing is performed. Recognize the fact that the emission current caused by flushing is 20μA to 40μA. Insert the sample holder into the sample chamber of the S-4800 housing. Press the [Origin] button on the control panel to move the sample holder to the observation position.

[0158] Click the acceleration voltage display to open the HV setting dialog box, then set the acceleration voltage to [5.0 kV] and the emission current to [20 μA]. On the [Basic] tab of the operation panel, set the signal selection mode to [SE]. Select [Up(U)] and [+BSE] in the SE detector, and select [LA100] in the selection box to the right of [+BSE] to set the mode for observing the reflected electron image. Similarly, on the [Basic] tab of the operation panel, set the probe current in the electron optical system condition block to [Normal], the focus mode to [UHR], and the WD to [3.0 mm]. Press the [ON] button in the acceleration voltage display of the control panel to apply the acceleration voltage. Focus the domain of the crystalline material observed in the dark under the above observation conditions and save the SEM image.

[0159] The image thus obtained was used to calculate the area occupied by the crystalline material per unit area using the image processing software "Image-Pro Plus (manufactured by MediaCybernetics Inc.)". The analysis area was analyzed within a circle with a diameter of 2.0 μm near the vertex where the toner particle had the smallest curvature. This analysis was performed on 100 toner particles. The ratio S1 (%) of the area occupied by the crystalline material in the first surface region relative to the area of ​​the toner surface was calculated.

[0160] <Calculation Method of the Area Ratio Occupied by the Crystalline Material in the Second Surface Region of the Toner and the Dispersion Diameter of the Domains>

[0161] A vacuum electron staining apparatus (Filgen, Inc., VSC4R1H) was used to calculate the ratio S2 (%) of the area occupied by the crystalline material near the toner surface (second surface region) relative to the area of ​​the toner surface and the dispersion diameter of the domains formed by the crystalline material. Calculations were performed using images obtained by observing a reflected electron image of a toner stained in a RuO4 atmosphere at 500 Pa for 15 minutes using a field emission scanning electron microscope S-4800 (Hitachi High-Technologies Corporation).

[0162] Inject liquid nitrogen into the anti-fouling trap installed on the shell of S-4800 until the liquid nitrogen overflows, and then leave it for 30 minutes. Activate the "PC-SEM" of S-4800 to perform flushing (washing the FE chip that serves as the electron source). Click the acceleration voltage display part of the control panel on the interface of S-4800, and press its [Flush] button to open the flushing execution dialog box. Recognize the fact that the flushing intensity is 2, and flush. Recognize the fact that the emission current caused by flushing is 20μA to 40μA. Insert the sample holder into the sample chamber of the shell of S-4800. Press the [Origin] button on the control panel to move the sample holder to the observation position.

[0163] Click the acceleration voltage display to open the HV setting dialog box, then set the acceleration voltage to [5.0 kV] and the emission current to [20 μA]. In the [Basic] tab of the operation panel, set the signal selection mode to [SE]. Select [Up(U)] and [+BSE] in the SE detector, and select [LA100] in the selection box to the right of [+BSE] to set the mode for observing the reflected electron image. Similarly, in the [Basic] tab of the operation panel, set the probe current in the electron optical system condition block to [Normal], the focus mode to [UHR], and the WD to [3.0 mm]. Press the [ON] button in the acceleration voltage display of the control panel to apply the acceleration voltage. Focus the domain of the crystalline material observed in the dark under the above observation conditions and save the SEM image.

[0164] The image thus obtained was used to calculate the ratio of the area occupied by the crystalline material and the dispersion diameter of the domains using the image processing software "Image-Pro Plus (manufactured by MediaCybernetics Inc.)". The analysis area was analyzed within a circle having a diameter of 2.0 μm near the vertex where the curvature of the toner particle was minimum.

[0165] Regarding the domain dispersion diameter, all domains each having an area-equivalent circle diameter of 5 nm or more and 500 nm or less in the analysis area of ​​100 toner particles were measured, and the number average of their area-equivalent circle diameters was calculated. Whether or not microdomains of crystalline material were formed was determined, and the number average thus obtained was defined as the domain dispersion diameter of the crystalline material.

[0166] Regarding the ratio of the area occupied by the crystalline material, the above analysis is performed on 100 toner particles, and the ratio S2 (%) of the area occupied by the crystalline material in the second surface region of the toner relative to the area of ​​the toner surface is calculated.

[0167] <Calculation Method of Dispersion Diameter of Crystalline Material Domains>

[0168] The dispersion diameter of the domains of the crystalline material refers to a number average value measured from the area-equivalent circle diameters of the domains of the crystalline material based on a cross-sectional image of toner particles observed by a transmission electron microscope (TEM).

[0169] A cross section of a toner particle observed by a transmission electron microscope (TEM) is produced as follows.

[0170] An Os film (5 nm) and a naphthalene film (20 nm) were applied to the toner as protective films using an osmium plasma coater (Filgen, Inc., OPC80T), and the resultant was embedded in a photocurable resin D800 (JEOL Ltd.). The resultant was then cut with an ultrasonic ultramicrotome (Leica Microsystems, UC7) at a cutting speed of 1 mm / s to produce a toner particle cross-section having a thickness of 60 nm (or 70 nm).

[0171] The cross section thus obtained was stained using a vacuum electron staining apparatus (Filgen, Inc., VSC4R1H) in a RuO4 atmosphere at 500 Pa and subjected to STEM observation using the STEM function of a STEM (JEOL Ltd., JEM2800). The size of the STEM probe was 1 nm, and an image having a size of 1,024 pixels × 1,024 pixels was obtained.

[0172] For the obtained image, the area circle equivalent diameter of the domain was measured by using image processing software "Image-Pro Plus (manufactured by Media Cybernetics Inc.)".

[0173] Ruthenium staining of toner particle cross-sections does not stain the crystalline material. Therefore, when observed under TEM, domains of the crystalline material appear black, making the domains identifiable. To calculate the dispersion diameter, the cross-sections of 100 toner particles were observed. All domains with a dispersion diameter of 5 nm or more and 500 nm or less were measured, and the number average of their dispersion diameters was calculated. Whether microdomains of crystalline material were formed was determined, and the resulting number average was defined as the dispersion diameter of the crystalline material domains.

[0174] <Calculation Method of the Surface Existence Index of Magnetic Materials>

[0175] The index of magnetic material existing near the surface is the number of magnetic materials existing near the surface of the magnetic toner particles and is expressed as a square per 1 μm. 2 The number of surface areas.

[0176] The near-surface existence index is calculated by using an image obtained by observing a reflected electron image of the toner with a field emission scanning electron microscope S-4800 (Hitachi High-Technologies Corporation).

[0177] Inject liquid nitrogen into the anti-fouling trap installed on the shell of S-4800 until the liquid nitrogen overflows, and then leave it for 30 minutes. Activate the "PC-SEM" of S-4800 to perform flushing (washing the FE chip as the electron source). Click the acceleration voltage display part of the control panel on the interface of S-4800, and press its [Flush] button to open the flushing execution dialog box. Recognize the fact that the flushing intensity is 2, and flush. Recognize the fact that the emission current caused by flushing is 20μA to 40μA. Insert the sample holder into the sample chamber of the shell of S-4800. Press the [Origin] button on the control panel to move the sample holder to the observation position.

[0178] Click the accelerating voltage display to open the HV setting dialog box. Then, set the accelerating voltage to [5.0 kV] and the emission current to [20 μA]. On the [Basic] tab of the operation panel, set the signal selection mode to [SE]. Select [Up(U)] and [+BSE] for the SE detector, and select [LA100] in the selection box to the right of [+BSE] to set the mode for observing the reflected electron image. Similarly, on the [Basic] tab of the operation panel, set the probe current in the electron optical system condition block to [Normal], the focus mode to [UHR], and the WD to [3.0 mm]. Press the [ON] button in the accelerating voltage display of the control panel to apply the accelerating voltage.

[0179] Under the above observation conditions, the magnetic material is observed in a state of emitting white light. The luminous magnetic material is focused, and its SEM image is saved. The image analysis software image-J is used for this image so that the number of magnetic materials as peaks of brightness can be detected, and then the number of magnetic materials per unit area is calculated. The above analysis is performed on 100 toner particles, and the average value of the measured values is defined as the coefficient of presence near the surface.

[0180] <Measurement of IR and Calculation Method of [Si-O-Si] / [Si-C] Value>

[0181] Using a Fourier transform infrared spectrometer (Spectrum One: manufactured by PerkinElmer Co., Ltd.) equipped with a Universal ATR Sampling Accessory, the FT-IR spectrum is measured by the ATR method. The specific measurement process is described as follows.

[0182] The incident angle of infrared light (λ = 5μm) is set to 45°. A Ge ATR crystal (refractive index: 4.0) is used as the ATR crystal. Other conditions are described as follows.

[0183] Range

[0184] Start: 4,000 cm -1

[0185] End: 600 cm -1

[0186] Duration

[0187] Number of scans: 16

[0188] Resolution: 4.00 cm -1

[0189] (1) Place the Ge ATR crystal on the device.

[0190] (2) Weigh precisely 0.01 g of the toluene extract of iron oxide particles on the ATR crystal.

[0191] (3) Press the sample with the pressure arm and measure its FT-IR (Force Gauge: 90).

[0192] (4) Perform baseline correction on the obtained FT-IR spectrum by automatic correction.

[0193] (5) Calculate the range of [Si-O-Si] from 990 cm -1 to 1,040 cm -1 and 1,240 cm -1Up to 1,280cm -1 The ratio of the maximum value of the absorption peak intensity between the ranges of [Si-C] is [Si-O-Si] / [Si-C].

[0194] <Calculation method of the value obtained by dividing the mass change rate of the magnetic material with respect to relative humidity by the specific surface area>

[0195] As an indication of the water content of the hydrophobized magnetic material, a value (mass change rate / specific surface area) is calculated, which is obtained by dividing the mass change rate of the hydrophobized magnetic material when the hydrophobized magnetic material is placed in an environment with a temperature of 30°C and a relative humidity of 0% for 24 hours and then placed in an environment with a temperature of 30°C and a relative humidity of 80% for 1 hour by the specific surface area of ​​the hydrophobized magnetic material.

[0196] The mass change rate of the magnetic material was measured using a calorimetric measuring device "Q5000SA" (manufactured by TA Instruments). About 20 mg of the magnetic material was placed in a sample pan. A program was set so that the environment in the chamber could be set to have a temperature of 30°C and a relative humidity of 0%, and the environment could be maintained for 24 hours. Then, the environment could be maintained at a temperature of 30°C and a relative humidity of 80% for 1 hour, and then the measurement was started. The mass after 24 hours from the start was expressed as TGA1, the mass after 1 hour under an environment of a temperature of 30°C and a relative humidity of 80% was expressed as TGA2, and ((TGA2-TGA1) / TGA1)×100 was defined as the mass change rate (%).

[0197] In addition, the specific surface area of ​​the magnetic material was determined according to JIS Z8830 (2001) by the BET method based on nitrogen adsorption. An automatic specific surface area / pore distribution measuring device "TriStar3000" (manufactured by Shimadzu Corporation) using a gas adsorption method based on a constant volume method as a measuring system was used as a measuring device. The setting of the measurement conditions and the analysis of the measurement data were performed using the dedicated software "TriStar 3000Version 4.00" attached to the device, and a vacuum pump, a nitrogen pipe, and a helium pipe were connected to the device. Nitrogen was used as the adsorption gas, and the value calculated by the BET multipoint method was defined as the BET specific surface area in the present invention. The BET specific surface area was calculated as follows. First, nitrogen was adsorbed onto the magnetic material, and the equilibrium pressure P (Pa) in the sample cell and the nitrogen adsorption amount Va (mol·g) of the magnetic material in this case were measured. -1 Then, the relative pressure Pr, which is a value obtained by dividing the equilibrium pressure P (Pa) in the sample cell by the saturated vapor pressure Po (Pa) of nitrogen, is plotted on the horizontal axis, and the nitrogen adsorption amount Va (mol·g -1 ) is plotted on the vertical axis to obtain the adsorption isotherm.

[0198] Then, the adsorption amount Vm (mol·g) of the monomolecular layer required to form a monomolecular layer on the surface of the magnetic material was determined by using the following BET formula: -1 ).

[0199] Pr / Va(1-Pr)=1 / (Vm×C)+(C-1)×Pr / (Vm×C)

[0200] Here, C represents a BET parameter, which is a variable that changes depending on the type of measurement sample, the type of adsorbed gas, and the adsorption temperature.

[0201] When the X-axis represents PR and the Y-axis represents Pr / Va(1-Pr), the BET formula can be understood as a straight line having a slope of (C-1) / (Vm×C) and an intercept of 1 / (Vm×C) (this straight line is called a BET diagram).

[0202] Slope of the line = (C-1) / (Vm×C)

[0203] Intercept of the line = 1 / (Vm×C)

[0204] When the actual value of Pr and the actual value of Pr / Va(1-Pr) are plotted in a graph, a straight line is drawn by the least square method, and the values ​​of the slope and intercept of the straight line can be calculated. When the simultaneous equations of the above slope and intercept are solved by using those values, Vm and C can be calculated. Further, from the Vm calculated in the above and the cross-sectional area occupied by the nitrogen molecule (0.162 nm 2 ), the BET specific surface area S (m 2 ·g -1 ).

[0205] S=Vm×N×0.162×10 -18

[0206] Where N is Avogadro's constant (mol -1 ).

[0207] The measurement using the device followed the "TriStar 3000 Instruction Manual V4.0" included with the device, but specifically, the measurement was performed by the following procedure.

[0208] Accurately weigh the tare weight of a dedicated glass sample cell (stem diameter: 3 / 8 inch, volume: about 5 ml) that has been fully washed and dried. Then, about 1.5 g of magnetic material is loaded into the sample cell using a funnel. The sample cell that will hold the magnetic material is placed in a pre-treatment device "VacPrep 061" (manufactured by Shimadzu Corporation) in which a vacuum pump and a nitrogen tube are connected to each other, and continuously vacuum degassed at 23°C for about 10 hours. During vacuum degassed, degassed and adjusted valves are gradually performed so that the magnetic material is not attracted to the vacuum pump. Along with degassed, the pressure in the cell gradually decreases and eventually reaches about 0.4 Pa (about 3 mTorr). After completing vacuum degassed, nitrogen is gradually injected so that the pressure in the sample cell is restored to atmospheric pressure, and the sample cell is taken out from the pre-treatment device. Then, accurately weigh the quality of the sample cell, and calculate the accurate quality of the magnetic material from the difference with the tare weight. In this case, during weighing, the sample cell is covered with a rubber stopper so that the magnetic material in the sample cell is not polluted by moisture in the atmosphere, etc. Then, a special "isothermal jacket" is attached to the rod of the sample cell that accommodates the magnetic material. Then, a special filler rod is inserted into the sample cell and the sample cell is placed in the analysis port of the device. The isothermal jacket is a tubular member with an inner surface formed by a porous material and an outer surface formed by an impermeable material, which can absorb a certain level of liquid nitrogen by capillary action. Thereafter, the free space of the sample cell including the connection tool is measured. The free space is calculated as follows: at 23°C, the volume of the sample cell is measured by using helium, thereafter the sample cell is cooled with liquid nitrogen, and then the volume of the sample cell is measured in the same way by using helium, followed by conversion by the difference in volume. In addition, by using the Po tube built into the device, the saturated vapor pressure Po (Pa) of nitrogen is automatically measured respectively. Then, after vacuum degassing in the sample cell, the sample cell is cooled with nitrogen while continuing vacuum degassing. Then, nitrogen is introduced into the sample cell in a step-by-step manner so that nitrogen molecules are adsorbed to the magnetic material. In this case, the above-mentioned adsorption isotherm is obtained by measuring the equilibrium pressure P (Pa) as needed, thereby converting the adsorption isotherm into a BET diagram. The point of the relative pressure Pr for collecting data is set to 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30, a total of 6 points. By the least squares method, a straight line is drawn relative to the measurement data thus obtained, and Vm is calculated by the slope and intercept of the straight line. Further, by using the value of Vm, the BET specific surface area of ​​the magnetic material is calculated as described above.

[0209] Example

[0210] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In the following formulations, the terms "parts" and "%" are based on mass unless otherwise specified.

[0211] <Production Example of Magnetic Material 1>

[0212] An aqueous solution containing ferrous hydroxide was prepared by mixing 1.00 to 1.10 equivalents of caustic soda solution relative to the iron element, 0.15% by mass of P2O5 calculated as phosphorus relative to the iron element, and 0.50% by mass of SiO2 calculated as silicon relative to the iron element with an aqueous ferrous sulfate solution. The pH of the aqueous solution was set to 8.0, and an oxidation reaction was carried out at 85°C while blowing air into the solution. A slurry containing seed crystals was thus prepared.

[0213] Then, an aqueous solution of ferrous sulfate is added to the slurry so that the amount is 0.90 equivalents to 1.20 equivalents relative to the initial amount of alkali (sodium component of caustic soda). Then, the slurry is maintained at pH 7.6 and an oxidation reaction is carried out while blowing air into it. Thus, a slurry containing iron oxide is obtained. After filtering and washing the slurry, the aqueous slurry is taken out at one time. In this case, a small amount of aqueous sample is collected and the water content is measured. Then, the aqueous sample is loaded into another aqueous medium without drying, and the slurry is redispersed with a pin mill under stirring while circulating so that the pH of the redispersed liquid is adjusted to 9.0 (processing pH: 1). Then, 1.4 parts by mass of isobutyltrimethoxysilane is added to 100 parts by mass of iron oxide particles (the amount of iron oxide particles is calculated as the value obtained by subtracting the water content from the amount of the aqueous sample) while stirring, and hydrolysis is carried out at a liquid temperature of 45°C. Thereafter, the hydrophobized magnetic material produced by the following hydrophobic treatment was filtered by a filter press, washed with a large amount of water, and then dried at 120° C. for 2 hours: The slurry was dispersed with a pin mill under sufficient stirring while circulating so that the pH of the dispersion was adjusted to 9.0 (treatment pH: 2). The particles thus obtained were crushed and passed through a sieve having an opening of 100 μm, thereby obtaining a magnetic material 1 having a number average particle size of 0.26 μm.

[0214] <Production Examples of Magnetic Materials 2 to 13, and 15 and 16>

[0215] Magnetic materials 2 to 13, and 15 and 16 were obtained under the same conditions using the same equipment as those in the case of producing magnetic material 1, except that the hydrophobizing agent and treatment conditions (hydrophobizing agent and treatment pH) were changed to those shown in Table 1. The physical property values ​​of the magnetic materials are shown in Table 1.

[0216] <Production Example of Magnetic Material 14>

[0217] An aqueous solution containing ferrous hydroxide was prepared by mixing 1.00 to 1.10 equivalents of caustic soda solution relative to the iron element, 0.15% by mass of P2O5 calculated as phosphorus relative to the iron element, and 0.50% by mass of SiO2 calculated as silicon relative to the iron element with an aqueous ferrous sulfate solution. The pH of the aqueous solution was set to 8.0, and an oxidation reaction was carried out at 85°C while blowing air into the solution. A slurry containing seed crystals was thus prepared.

[0218] Then, an aqueous solution of ferrous sulfate is added to the slurry so that the amount is 0.90 equivalent to 1.20 equivalent relative to the initial amount of alkali (sodium component of caustic soda). Then, the slurry is maintained at pH 7.6 and an oxidation reaction is carried out while air is blown into it. Therefore, in the final stage of the oxidation reaction, the pH is adjusted to 6.0. The resultant is washed with water and dried, and the particles thus obtained are subjected to a crushing process to obtain a magnetic material with a volume average particle size of 0.23 μm.

[0219] As a hydrophobizing agent, 30 parts by mass of isobutyltrimethoxysilane was added dropwise to 70 parts by mass of ion-exchanged water with stirring. The aqueous solution was then maintained at a pH of 5.5 and a temperature of 55°C and hydrolyzed by dispersing it for 120 minutes using a dispersing blade at a peripheral speed of 0.46 m / s. The pH of the aqueous solution was then adjusted to 7.0, and the aqueous solution was cooled to 10°C to terminate the hydrolysis reaction. In this manner, an aqueous solution containing a silane compound was obtained.

[0220] 100 parts by mass of iron oxide particles were loaded into a high-speed mixer (LFS-2 type manufactured by Fukae Powtec Co., Ltd.), and an aqueous solution containing a silane compound was added dropwise within 2 minutes while stirring at a rotation speed of 2,000 rpm. Thereafter, the material was mixed and stirred for 5 minutes. Then, in order to increase the fixation of the silane compound, the mixture was dried at 40°C for 1 hour to reduce moisture. The mixture was then dried at 110°C for 3 hours to carry out the condensation reaction of the silane compound. Thereafter, the resultant was crushed and passed through a sieve with an opening of 100 μm to obtain a magnetic material 14. The processing conditions and physical property values ​​of the magnetic material are shown in Table 1.

[0221] <Production Example of Magnetic Material 17>

[0222] An aqueous solution containing ferrous hydroxide was prepared by mixing 1.00 to 1.10 equivalents of caustic soda solution relative to the iron element, 0.15% by mass of P2O5 calculated as phosphorus relative to the iron element, and 0.50% by mass of SiO2 calculated as silicon relative to the iron element with an aqueous ferrous sulfate solution. The pH of the aqueous solution was set to 8.0, and an oxidation reaction was carried out at 85°C while blowing air into the solution. A slurry containing seed crystals was thus prepared.

[0223] Then, an aqueous solution of ferrous sulfate was added to the slurry so that the amount was 0.90 to 1.20 equivalents relative to the initial amount of alkali (sodium component of caustic soda). The slurry was then maintained at pH 7.6 and an oxidation reaction was carried out while air was blown into it. Thus, in the final stage of the oxidation reaction, the pH was adjusted to 6. The resultant was washed with water and dried, and the particles thus obtained were crushed to obtain magnetic particles having a volume average particle size of 0.23 μm.

[0224] After the magnetic particles were loaded into a Henschel mixer (Nippon Coke & Engineering Co., Ltd. (formerly Mitsui Miike Chemical Engineering Machinery, Co., Ltd.)), silicone oil (3.8 parts by mass) was added by spraying while the untreated iron oxide particles were dispersed at a rotation speed of 34.5 m / s, and the oil was then dispersed as is for 10 minutes. The resultant was then passed through a sieve with an opening of 100 μm to obtain Magnetic Material 17. The treatment conditions and physical property values ​​of the magnetic material are shown in Table 1.

[0225] <Production Example of Toner Particles 1>

[0226] 450 parts of Na3PO4 aqueous solution (0.1 mol / L) were added to 720 parts of ion-exchanged water, and the mixture was heated to 60°C. Then, 67.7 parts by mass of CaCl2 aqueous solution (1.0 mol / L) were added. The mixture was stirred at 1,200 rpm using Claremix (manufactured by MTechnique Co., Ltd.) to prepare an aqueous medium.

[0227] (Magnetic material dispersion step)

[0228]

[0229] (Saturated polyester resin obtained by polycondensation of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid, number average molecular weight (Mn) = 5,000, acid value = 6 mgKOH / g, glass transition temperature (Tg) = 68°C).

[0230] The above formulation was processed by using Cavitron (manufactured by Eurotech) at a peripheral speed of a rotor of 35 m / s for 2 hours, and these materials were uniformly dispersed and mixed to obtain a polymerizable monomer containing a magnetic material.

[0231] (Polymerizable Monomer Composition Preparation Step)

[0232] The polymerizable monomer containing the magnetic material obtained in the magnetic material dispersion step was heated to 63° C., and the following raw materials were added thereto. The mixture was treated at a rotor peripheral speed of 35 m / s using a Cavitron (manufactured by Eurotech) for 1 hour to obtain a polymerizable monomer composition.

[0233] · Crystalline material 1 10.0 parts

[0234] · Crystalline material 3 5.0 parts

[0235] (Granulation step and polymerization step)

[0236] The polymerizable monomer composition was added to the aqueous medium and stirred at 60°C in a nitrogen atmosphere at 1,200 r / min for 7 minutes using Claremix (manufactured by M Technique Co., Ltd.). 9.0 parts of tert-butyl peroxypivalate were added as a polymerization initiator. The resultant was then stirred for 13 minutes to form granules. The polymerization reaction was then carried out at 70°C for 4 hours while stirring with a paddle-type stirring blade. After the reaction was completed, the temperature of the dispersion containing the resin particles was raised to 100°C and maintained for 2 hours.

[0237] (Cooling Step)

[0238] Thereafter, as a cooling step, room-temperature water was added to the suspension. The suspension was cooled from 100°C to 50°C at a rate of 40°C / minute, and then allowed to cool to room temperature. Hydrochloric acid was then added to the suspension, and the suspension was thoroughly washed to dissolve the dispersion stabilizer, followed by filtration and drying. Thus, Toner Particles 1 were obtained. The formulation and production method of Toner Particles 1 are shown in Table 3.

[0239] <Production Example of Toner 1>

[0240] 100 parts of the toner particles 1 and 0.8 parts of a 300 m 2 The hydrophobic silica fine particles having a BET value of 1.5 Å / g and a number average primary particle size of 8 nm were mixed to obtain Toner 1. The physical property values ​​of Toner 1 are shown in Table 4.

[0241] <Production Example of Toner Particles 2 to 21 and Toner Particles 23 to 26>

[0242] Toner particles 2 to 21 and toner particles 23 to 26 were obtained in the same manner as in the production example of toner particles 1, except that the formulation and production method of the toner particles in the production example of toner particles 1 were changed as shown in Table 3. The type numbers of the first crystalline material and the second crystalline material used are shown in Table 3, and the relationship between the type numbers and names of the crystalline materials is shown in Table 2. Crystalline polyester 1 in Table 2 is a condensate of 1,9-nonanediol and sebacic acid (acid value: 2.0 mgKOH / g, weight average molecular weight Mw: 20,400).

[0243] <Production Example of Toner Particles 22>

[0244] (Preparation of Resin Particle Dispersion 1)

[0245]

[0246]

[0247] The above materials were loaded into a 5-liter flask equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a distillation column. The temperature in the flask was raised to 210°C over 1 hour, and 1 part of titanium tetraethoxide was added to 100 parts of the above materials. The temperature was raised to 230°C over 0.5 hours while distilling off the generated water, and the dehydration condensation reaction was continued at this temperature for 1 hour. The reaction product was then cooled. In this manner, amorphous resin 1 having a weight-average molecular weight of 18,500, an acid value of 14 mgKOH / g, and a glass transition temperature of 59°C was synthesized.

[0248] 40 parts of ethyl acetate and 25 parts of 2-butanol were added to a container equipped with a temperature control unit and a nitrogen displacement unit to prepare a mixed solvent. Then, 100 parts of amorphous resin 1 were gradually added to dissolve the mixture. A 10% by mass aqueous ammonia solution (an amount equal to 3 times the acid value of the resin in terms of molar ratio) was added to the mixture, and the mixture was stirred for 30 minutes.

[0249] Then, the inside of the container was replaced with dry nitrogen, and the temperature was maintained at 40°C. While stirring the mixed solution, 400 parts of ion exchange water were added dropwise at a rate of 2 parts / minute to perform emulsification. After the addition was completed, the temperature of the emulsion was returned to room temperature (20°C to 25°C), and bubbling was performed with dry nitrogen for 48 hours under stirring to reduce the amount of each of ethyl acetate and 2-butanol to 1,000 ppm or less. Thus, a resin particle dispersion in which resin particles having a volume average particle size of 200 nm were dispersed was obtained. Ion exchange water was added to the resin particle dispersion to adjust the solid content to 20% by mass to obtain a resin particle dispersion (1).

[0250] (Preparation of Resin Particle Dispersion 2)

[0251] Resin Particle Dispersion Liquid 2 is obtained in the same manner as in the preparation of Resin Particle Dispersion Liquid 1, except that Non-Crystalline Resin 2 is used instead of Non-Crystalline Resin 1.

[0252] Amorphous Resin 2 was prepared as follows: 100 parts by mass of a mixture obtained by mixing the following materials in the molar ratio described below and 0.52 parts by mass of tin di(2-ethylhexanoate) serving as a catalyst were loaded into a polymerization tank equipped with a nitrogen introduction tube, a dehydration tube, and a stirrer.

[0253]

[0254]

[0255] The polymerization tank was then placed in a nitrogen atmosphere, and a polycondensation reaction was allowed to proceed over 6 hours while being heated at 200°C. The temperature was then raised to 210°C, and 0.25 parts of trimellitic anhydride was added. The pressure in the polymerization tank was reduced to 40 kPa. The condensation reaction then proceeded further. This resin was designated as amorphous resin 2 (weight-average molecular weight Mw: 12,100).

[0256]

[0257] (Preparation of Resin Particle Dispersion 3)

[0258] Resin Particle Dispersion Liquid 3 was obtained in the same manner as in the preparation of Resin Particle Dispersion Liquid 1, except that Non-Crystalline Resin 3 was used instead of Non-Crystalline Resin 1.

[0259] Amorphous Resin 3 was prepared as follows: 100 parts by mass of a mixture obtained by mixing the following materials in the molar ratio described below and 0.52 parts by mass of tin di(2-ethylhexanoate) serving as a catalyst were loaded into a polymerization tank equipped with a nitrogen introduction tube, a dehydration tube, and a stirrer.

[0260]

[0261] The polymerization tank was then placed in a nitrogen atmosphere, and a polycondensation reaction was allowed to proceed over 6 hours while being heated at 200°C. The temperature was then raised to 210°C, and 5.0 parts of trimellitic anhydride was added. The pressure in the polymerization tank was reduced to 40 kPa. The condensation reaction then continued. This resin was designated Amorphous Resin 3 (weight-average molecular weight Mw: 9,800).

[0262] (Preparation of Colorant Particle Dispersion Liquid 1)

[0263] Cyan pigment CI Pigment Blue 15:3 (copper phthalocyanine manufactured by DIC Corporation, trade name: FastogenBlue LA5380): 70.0 parts

[0264] Anionic surfactant (Neogen RK manufactured by DKS Co., Ltd.): 5.0 parts

[0265] Ion exchange water: 200.0 parts

[0266] The above materials were mixed and dispersed for 10 minutes using a homogenizer (ULTRA-TURRAX T50 manufactured by IKA Co., Ltd.). Ion-exchanged water was added so that the solid content in the dispersion liquid was 20% by mass. Thus, a colorant particle dispersion liquid in which colorant particles having a volume average particle diameter of 190 nm were dispersed was obtained.

[0267] (Preparation of Release Agent Particle Dispersion 1)

[0268] Crystalline material 1: 100.0 parts

[0269] Anionic surfactant (Neogen RK manufactured by DKS Co., Ltd.): 5.0 parts

[0270] Ion exchange water: 350.0 parts

[0271] The above materials were mixed and heated to 100°C, and dispersed using a homogenizer (ULTRA-TURRAX T50 manufactured by IKA Co., Ltd.). Thereafter, the resultant was subjected to a dispersion treatment using a Manton Gorin high-pressure homogenizer (manufactured by Manton Gorin Co., Ltd.) to obtain a release agent particle dispersion (solid content: 20% by mass) in which release agent particles 1 having a volume average particle diameter of 90 nm were dispersed.

[0272] (Preparation of Toner Particles 22)

[0273] An apparatus was prepared in which a circular stainless steel flask and a container A were connected to each other via a tube pump A so that the liquid contained in the container A was supplied to the flask by driving the tube pump A, and container A and container B were connected to each other via a tube pump B so that the liquid contained in the container B was supplied to the container A by driving the tube pump B. Then, the following operation was performed by using this apparatus.

[0274] Resin particle dispersion 1: 500.0 parts

[0275] Colorant particle dispersion 1: 40.0 parts

[0276] Anionic surfactant (TaycaPower): 2.0 parts

[0277] The above materials were loaded into a round stainless steel flask, to which 0.1N nitric acid was added to adjust the pH to 3.5. Then, 30.0 parts of a nitric acid aqueous solution having a polyaluminium chloride concentration of 10% by mass was added to the resultant. Thereafter, after the resultant was dispersed at 30°C using a homogenizer (ULTRA-TURRAX T50 manufactured by IKA Co., Ltd.), the particle size of each aggregated particle was grown while the temperature was increased at a rate of 1°C / 30 minutes in a heating oil bath.

[0278] At the same time, 50.0 parts of the resin particle dispersion 3 were loaded into container A, which was a polyester bottle, and similarly, 25 parts of the release agent particle dispersion 1 were loaded into container B. Then, the liquid supply rate of tube pump A was set to 0.70 parts / minute, and the liquid supply rate of tube pump B was set to 0.14 parts / minute. From the point at which the temperature in the circular stainless steel flask reached 37.0°C during the formation of aggregated particles, tube pumps A and B were driven to start supplying their respective dispersions. As a result, while the concentration of the release agent particles was gradually increased, a mixed dispersion in which the resin particles and the release agent particles 1 were dispersed was supplied from container A to the circular stainless steel flask during the formation of aggregated particles.

[0279] Then, from the point when the supply of each dispersion liquid to the flask was completed, the temperature in the flask reached 48° C., and the temperature was maintained for 30 minutes to form second aggregated particles.

[0280] Thereafter, 50 parts of Resin Particle Dispersion 2 was slowly added to the resultant, and the mixture was maintained for 1 hour, followed by the addition of a 0.1N sodium hydroxide aqueous solution to adjust the pH to 8.5. Thereafter, the resultant was heated to 85°C while continuing to stir, and then maintained for 5 hours. Thereafter, the resultant was cooled to 20°C at a rate of 20°C / min.

[0281] The above dispersion liquid is filtered, and then sufficiently washed with ion-exchanged water, followed by drying, to obtain toner particles 22 .

[0282] <Production Example of Toner Particles 27>

[0283] (Preparation of Resin Particle Dispersion 4)

[0284]

[0285] The above materials were loaded into a flask having an internal capacity of 5 liters and equipped with a stirring device, a nitrogen inlet pipe, a temperature sensor, and a rectification column, and dissolved to obtain a mixed solution. An aqueous solution obtained by mixing 1.5 parts of Neogen RK (manufactured by DKS Co., Ltd.) with 150.0 parts of ion-exchanged water was added to the mixed solution and dispersed therein.

[0286] Further, while the resultant was slowly stirred for 10 minutes, an aqueous solution obtained by mixing 0.3 parts of potassium persulfate with 10.0 parts of ion-exchanged water was added to the resultant.

[0287] After replacing the inside of the flask with nitrogen, emulsion polymerization was performed at 70° C. for 6 hours. After completion of the polymerization, the reaction solution was cooled to room temperature, and ion-exchanged water was added thereto to obtain a resin particle dispersion 4 having a solid content concentration of 12.5% ​​by mass and a volume-based median particle diameter of 0.2 μm.

[0288] Resin particle dispersion 4: 500.0 parts

[0289] Colorant particle dispersion 1: 40.0 parts

[0290] Release agent dispersion 1: 50.0 parts

[0291] The above materials were loaded into a round stainless steel flask and dispersed using a homogenizer (manufactured by IKA Co., Ltd.: ULTRA-TURRAX T50). Under stirring, the temperature in the container was adjusted to 30°C, and 1 mol / L of hydrochloric acid was added to adjust the pH of the mixture to 5.0. After the resultant was placed for 3 minutes, heating was started and the temperature was raised to 50°C to produce aggregated particles. In this state, the particle size of each aggregated particle was measured. When the weight-average particle size of the aggregated particles reached 6.2 μm, 1 mol / L of sodium hydroxide was added to adjust the pH to 8.0, thereby stopping the growth of the particles.

[0292] Thereafter, the temperature was raised to 95° C. to carry out fusion and spheroidization of the aggregated particles. When the average circularity of the particles reached 0.980, the temperature was lowered to 30° C. Thus, a toner particle dispersion liquid 1 was obtained.

[0293] Hydrochloric acid was added to the thus obtained toner particle dispersion 1 to adjust the pH to 1.5 or less, and the mixture was left under stirring for 1 hour. The mixture was then subjected to solid-liquid separation by a filter press to obtain a toner cake.

[0294] The toner cake was then dispersed again in ion-exchanged water. Dispersion and washing were repeated until the conductivity of the ion-exchanged water was sufficiently reduced. This yielded wet cake-like toner particles. The wet cake-like toner particles were then crushed and placed in a thermostatic bath at 40°C for 70 hours, followed by thorough drying to yield powdered toner particles 27.

[0295] <Production Example of Toner Particles 28>

[0296] (Production of Polyester Resin 1)

[0297] The following materials were mixed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube.

[0298]

[0299]

[0300] After the system was replaced with nitrogen through a decompression operation, the material was heated to 210°C and reacted for 5 hours while introducing nitrogen to remove generated water. Then, while continuing to stir, the temperature was gradually raised to 230°C under reduced pressure. The resultant was further reacted for 3 hours to synthesize Polyester Resin 1. The resin had a weight average molecular weight (Mw) of 9,500 and a Tg of 68°C.

[0301] (Production of Toner Core Particles 28)

[0302] The following materials were well mixed with an FM mixer (manufactured by Nippon Coke & Engineering Co., Ltd.) and then melt-kneaded with a twin-screw kneader (manufactured by Ikegai Ironworks Corp).

[0303]

[0304] The kneaded product thus obtained was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized product.

[0305] The coarsely pulverized product thus obtained was then finely pulverized using a Turbo Mill manufactured by Turbo Kogyo Co., Ltd. to obtain a finely pulverized product of approximately 5 μm. Thereafter, the finely pulverized product was further classified using a multi-stage classifier utilizing the Coanda effect, so that fine powder and coarse powder were discarded. Thus, toner core particles 28 were obtained. The toner core particles 28 had a weight-average particle size (D4) of 6.8 μm and a Tg of 58° C.

[0306] (Production of Toner Particle Dispersion Liquid 28)

[0307] The reaction solution containing 300.0 parts of ion-exchanged water was maintained at 30° C., and then 50.0 parts of an aqueous solution of an oxazoline-containing polymer ("Epocross (trademark) WS-300" manufactured by Nippon Shokubai Co., Ltd., monomer molar ratio: methyl methacrylate / 2-vinyl-2-oxazoline = 1 / 9, solid content concentration: 10% by mass) was loaded into the reaction vessel.

[0308] The contents of the reaction container were stirred thoroughly, and then 300.0 parts of toner core particles 28 were added. The mixture was stirred at 200 rpm for 1 hour. Thereafter, 300.0 parts of ion-exchanged water was added.

[0309] Thereafter, 6.0 parts of an aqueous ammonia solution having a concentration of 1% by mass was added to the reaction container, and then the temperature in the reaction container was raised to 60° C. at a rate of 0.5° C. / min under stirring at a rotation speed of 150 rpm.

[0310] After the temperature in the reaction vessel reached 60°C, the reaction vessel was maintained at 60°C for 1 hour while stirring at 100 rpm. One hour after the temperature in the reaction vessel reached 60°C, 10.0 parts of a 1% by mass aqueous acetic acid solution was added to the reaction vessel. Thereafter, the contents of the reaction vessel were maintained at 60°C for 30 minutes while stirring at 100 rpm.

[0311] Thereafter, an aqueous ammonia solution having a concentration of 1% by mass was added to the reaction container to adjust the pH in the reaction container to 7. Thereafter, the contents of the reaction container were cooled until their temperature reached room temperature (about 25° C.) Thus, a toner particle dispersion 28 was obtained.

[0312] (Production of Toner Particles 28)

[0313] The toner particle dispersion 28 is filtered and then dispersed again in ion-exchanged water. Dispersion and washing are repeated until the conductivity of the ion-exchanged water is sufficiently reduced. This yields wet cake-like toner particles. The wet cake-like toner particles are then crushed and placed in a thermostatic bath at 40°C for 70 hours, followed by thorough drying to yield powdered toner particles 28.

[0314] <Production Examples of Toners 2 to 28>

[0315] In the same manner as in the production example of toner 1, toners 2 to 28 were obtained from toner particles 2 to 28. The physical property values ​​of those toners are shown in Table 4.

[0316] <Example 1>

[0317] <Evaluation of Developability of Toner Using Laser Beam Printer>

[0318] A modified machine of a commercially available laser beam printer "LBP7600C" manufactured by Canon Inc. was used.

[0319] As a modification point, by changing the gears and software of the evaluation machine body, the number of rotations of the developing roller was set so that the developing roller rotates at twice the peripheral speed of the drum. 40 g of toner was loaded into the toner cartridge of the LBP7600C.

[0320] (1) Evaluation of developability on a medium having large unevenness (solid image unevenness and halftone image unevenness)

[0321] By using CS-680 (A4, basis weight: 68 g / m 2 , smoothness: 45 seconds, sold by Canon USA, Inc.), and the image was output under normal temperature and humidity environment (25°C / 50%RH).

[0322] First, 1,000 images with a 1% printing rate are output.

[0323] Furthermore, a fully solid image is output.

[0324] Thereafter, one halftone image is output (when the color range ranging from solid white to solid black is divided into 256 gray levels, the 49th gray level is counted from the solid white image).

[0325] (Evaluation criteria for solid image unevenness)

[0326] The image glossiness of the solid image was measured by using a gloss meter PG-3G (manufactured by Nippon Denshoku Industries Co., Ltd.), and the maximum and minimum values ​​of the glossiness were determined. The incident angle was set to 75 degrees.

[0327] A: 0.0 or more and less than 1.0

[0328] B: 1.0 or more and less than 2.0

[0329] C: 2.0 or higher and less than 3.0

[0330] D: 3.0 or higher and less than 4.0

[0331] E: 4.0 or above

[0332] (Evaluation criteria for halftone image unevenness)

[0333] The image glossiness of the halftone image was measured by using a gloss meter PG-3G (manufactured by Nippon Denshoku Industries Co., Ltd.), and the maximum and minimum values ​​of the glossiness were determined. The incident angle was set to 75 degrees.

[0334] A: 0.0 or more and less than 1.0

[0335] B: 1.0 or more and less than 1.5

[0336] C: 1.5 or more and less than 2.0

[0337] D: 2.0 or more and less than 3.0

[0338] E: 3.0 or above

[0339] (2) Evaluation of developability on a medium with large concavities and convexities (uneven solid image)

[0340] By using a medium having larger concavities and convexities than the medium of (1), Multi-Purpose Paper (A4, basis weight: 75 g / m 2 , smoothness: 25 seconds, sold by Canon USA, Inc.), and the image was output under normal temperature and humidity environment (25°C / 50%RH).

[0341] First, 1,000 images with a 1% printing rate are output.

[0342] Furthermore, a fully solid image is output.

[0343] (Evaluation criteria for solid image unevenness)

[0344] The image glossiness of the solid image was measured by using a gloss meter PG-3G (manufactured by Nippon Denshoku Industries Co., Ltd.), and the maximum and minimum values ​​of the glossiness were determined. The incident angle was set to 75 degrees.

[0345] A: 0.0 or more and less than 1.0

[0346] B: 1.0 or more and less than 2.0

[0347] C: 2.0 or higher and less than 3.0

[0348] D: 3.0 or higher and less than 4.0

[0349] E: 4.0 or above

[0350] (3) Evaluation of low-temperature fixability

[0351] By using LBP7600C modified so that its fixing temperature can be adjusted, the fixing temperature was changed from 140°C in increments of 5°C at a process speed of 300 mm / sec under a normal temperature and humidity environment (25°C / 50%RH). 2 ) is formed on a surface having a surface area of ​​0.40 mg / cm 2 The solid image of the toner load was formed by heating and pressing without oil to form a fixed image. The fixed image was formed by using Kimwipes (S-200 manufactured by Crecia Co., Ltd.) under an applied pressure of 7.35 kPa (75 g / cm 2 The fixed image was rubbed 10 times under a load of 100 ℃ and the temperature at which the image density reduction rate after rubbing compared with that before rubbing was less than 5% was defined as the fixing temperature, and then evaluated based on the following criteria.

[0352] For the image density measurement, the image density reduction rate was calculated by using a color reflection densitometer X-RITE 404A (manufactured by X-Rite Inc.).

[0353] (Evaluation criteria for low-temperature fixability)

[0354] A: less than 150℃

[0355] B: 150℃ or higher and less than 160℃

[0356] C: 160℃ or higher and less than 170℃

[0357] D: 170℃ or above

[0358] <Examples 2 to 22 and Comparative Examples 1 to 6>

[0359] The image drawing test was performed in the same manner as in Example 1, except that Toner 1 was changed to Toners 2 to 22 and Comparative Toners 23 to 28. The evaluation results of the toners are shown in Table 5.

[0360] Table 1

[0361]

[0362] Table 2

[0363] Crystalline material No. name Melting point (℃) Crystalline materials 1 Behenyl Behenate 75 Crystalline materials 2 Dipentaerythritol hexastearate 77 Crystalline materials 3 paraffin 75 Crystalline materials 4 Crystalline polyester 1 79

[0364] Table 3

[0365]

[0366] Table 4

[0367]

[0368] Table 5

[0369]

[0370] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A toner comprising toner particles containing a binder resin, a crystalline material, and a colorant, It is characterized by: The crystalline material is ester wax, hydrocarbon wax or crystalline polyester resin, and when The ratio of the area occupied by the crystalline material to the surface area of ​​the toner observed by a scanning electron microscope (SEM) after the toner is ruthenium-stained under the following conditions (1) is expressed as S1%, After the toner is ruthenium-stained under the following condition (2), on the surface of the toner observed with a scanning electron microscope (SEM), the ratio of the area occupied by the crystalline material to the surface area of ​​the toner is expressed as S2%, and When the dispersion diameter of a plurality of domains formed by the crystalline material on the toner surface observed with a scanning electron microscope SEM after the toner is stained with ruthenium under the following condition (2) is represented by R2 nm, Satisfy the following equations (1), (2), and (3): 0.0≤S1≤0.5 (1) 1.0≤S2≤10.0 (2) 20≤R2≤200 (3) wherein the condition (1) is to treat the toner in a ruthenium tetraoxide (RuO4) atmosphere at 100 Pa for 5 minutes, and The condition (2) is to treat the toner in a ruthenium tetraoxide (RuO 4 ) atmosphere at 500 Pa for 15 minutes.

2. The toner according to claim 1, wherein When a thin slice of the toner cut out with a microtome is stained with ruthenium under the following conditions (3), the dispersion diameter of the plurality of internal domains formed in the toner cross section observed with a transmission electron microscope TEM is represented as R i When nm Satisfies the following formula (4): R i <R2 (4) The condition (3) is to treat the toner in a ruthenium tetraoxide (RuO4) atmosphere at 500 Pa for 15 minutes. 3 . The toner according to claim 1 , wherein the crystalline material is the ester wax or the hydrocarbon wax. The toner according to claim 3 , wherein the crystalline material is the ester wax. 5 . The toner according to claim 1 , wherein the colorant is hydrophobized with a silane coupling agent. The toner according to claim 5 , wherein the colorant is a hydrophobized magnetic material.

7. The toner according to claim 6, wherein the peak intensity ratio [Si-O-Si] / [Si-C] of ATR-IR of a component extracted from the hydrophobized magnetic material with toluene is 1.4 to 2.5, wherein the peak intensity ratio [Si-O-Si] / [Si-C] of ATR-IR is calculated from an FT-IR spectrum measured by an ATR method using a Fourier transform infrared spectrometer equipped with a universal ATR measurement accessory.

8. The toner according to claim 6, wherein the hydrophobized magnetic material has a surface presence index of 4.0 to 8.0 pieces / 1 μm obtained by observing the toner with a scanning electron microscope (SEM). 2 , wherein the index of existence near the surface refers to the number of magnetic materials existing near the surface of the colorant particles, and the near the surface refers to the colorant surface observed by SEM in the colorant treated under the condition (2). 9 . The toner according to claim 6 , wherein the hydrophobized magnetic material has a hydrophobicity of 55 to 80.

10. The toner according to claim 6, wherein The mass change rate / specific surface area value is 0.002 to 0.020%·g / m 2 , which is obtained by dividing the rate of change in mass of the hydrophobized magnetic material when the hydrophobized magnetic material is allowed to stand under an environment of a temperature of 30°C and a relative humidity of 0% for 24 hours and then allowed to stand under an environment of a temperature of 30°C and a relative humidity of 80% for 1 hour by the specific surface area of ​​the hydrophobized magnetic material, wherein the specific surface area of ​​the hydrophobized magnetic material is measured by the BET method based on nitrogen adsorption in accordance with JIS Z8830:2001.

11. The toner according to claim 6, in, In the hydrophobized magnetic material, the spectrum of Si obtained by near-edge X-ray absorption fine structure NEXAFS and total electron yield TEY method has Peak A in the range of 1,844.4 to 1,844.8 eV, and Peak B in the range of 1,846.1 to 1,846.6 eV, and Among them, when The area of ​​peak A is calculated from A express, The area of ​​peak B is calculated from B Indicates that, and The number of moles of Si derived from the silane compound contained in 1 g of the hydrophobized magnetic material is represented by M Si When indicating, I A / (I A +I B ) / M Si is 40 to 55. 12 . The toner according to claim 1 , wherein the binder resin comprises a styrene acrylic resin or a polyester resin.

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