Toner, developer, and image forming method for developing electrostatic images

Abstract

This invention provides a toner for electrostatic image development that can suppress development leakage and reduce image density fluctuations. [Solution] A toner for developing electrostatic images, comprising toner matrix particles and an external additive, wherein the external additive comprises at least inorganic fine particles, the inorganic fine particles have a surface modifier on their surface and contain free components, the weight-average molecular weight of the free components is 1000 or more and 20000 or less, the content of the free components is 2 mg / kg or more and 700 mg / kg or less, and the free components are chloroform extracts from methyl ethyl ketone insoluble matter extracted from the electrostatic image developing toner using methanol.

Description

[Technical Field] 【0001】 The present invention relates to a toner for electrostatic image development, a developer, and an image forming method. [Background technology] 【0002】 In recent years, there has been increasing demand in the commercial printing sector for so-called high-coverage printing using electrophotographic processes. High-coverage printing is printing with a high coverage rate and therefore consumes a large amount of toner. The coverage rate is the percentage of the printed area calculated from the actual toner consumption, with the toner consumption when printing the entire printable area of ​​a page in one color being 100%. Furthermore, there is a demand for faster printing to increase productivity. Such high-coverage printing and high-speed printing place a heavy load on the developer. In other words, in recent years, there has been an increase in printing that places a higher load on the developer than before. In particular, when using a two-component developer that mixes toner and carrier, the load on the carrier becomes even greater. This increased load on the carrier has led to the problem of image defects becoming more likely. 【0003】 Conventionally, electrostatic image developers have been disclosed that attempt to suppress the decrease in image density when low-image-density images are output continuously (see, for example, Patent Document 1). However, they have not been able to suppress image defects when so-called high-coverage printing is performed. 【0004】 Furthermore, a two-component developer has been disclosed that contains toner particles surface-modified with silicone oil and an external additive with a high free carbon content, and which aims to suppress lead area whitening (see, for example, Patent Document 2). [Prior art documents] [Patent Documents] 【0005】 [Patent Document 1] Japanese Patent Publication No. 2015-230376 [Patent Document 2] Japanese Patent Application Laid-Open No. 2019-86705 【SUMMARY OF THE INVENTION】 【PROBLEMS TO BE SOLVED BY THE INVENTION】 【0006】 When the load on the carrier is large, the core material is likely to be exposed due to the wear of the coating resin. And when the core material is exposed, the electrical resistance of the carrier decreases, and development leakage occurs in the development nip portion. Then, image defects occur due to the occurrence of development leakage. On the other hand, the two-component developer described in Patent Document 2 has toner particles that are surface-modified with silicone oil and contain an external additive with a high free carbon ratio, so that highly insulating silicone oil is efficiently transferred to the carrier. And thereby, the variation in the resistance of the carrier is suppressed, and development leakage is suppressed even after long-term use. 【0007】 On the other hand, when there is a large amount of free silicone oil, the amount of silicone oil transferred from the toner to the carrier increases. In high-coverage printing, it has been found that when the amount of silicone oil transferred to the carrier increases in this way, the charging performance of the carrier deteriorates, and problems such as fluctuations in image density occur. In high-speed high-coverage printing, it is required to maintain stable image quality even when the load on the carrier is large and the toner is frequently replaced. 【0008】 The present invention has been made in view of the above problems and situations. The problem to be solved by the present invention is to provide an electrostatic charge image developing toner, a developer, and an image forming method capable of suppressing development leakage and suppressing fluctuations in image density. 【MEANS FOR SOLVING THE PROBLEM】 【0009】 In order to solve the above problems, the present inventor has intensively studied the released components from the toner for electrostatic charge image development. As a result, the present inventor has found that the weight average molecular weight and content of the released components from the toner for electrostatic charge image development greatly affect the development leakage and image density variation, and thus arrived at the present invention. That is, the above problems according to the present invention are solved by the following means. 【0010】 1. A toner for electrostatic charge image development having toner base particles and external additives, wherein the external additives contain at least inorganic fine particles, the inorganic fine particles have a surface modifier on the surface, the weight average molecular weight of the released components is 1000 or more and 20000 or less, the content of the released components is 2 mg / kg or more and 700 mg / kg or less, and the released components are chloroform extracts from methyl ethyl ketone-insoluble substances extracted from the toner for electrostatic charge image development with methanol, and is characterized by a toner for electrostatic charge image development. 【0011】 2. When the weight average molecular weight of the released components is Mw and the number average molecular weight of the released components is Mn, the value of Mw / Mn is 1 or more and 3 or less, and is characterized by the toner for electrostatic charge image development according to item 1. 【0012】 3. The weight average molecular weight of the released components is 1000 or more and 10000 or less, and is characterized by the toner for electrostatic charge image development according to item 1. 【0013】 4. The content of the released components is 2 mg / kg or more and 500 mg / kg or less, and is characterized by the toner for electrostatic charge image development according to item 1. 【0014】 5. The surface modifier is silicone oil, and is characterized by the toner for electrostatic charge image development according to item 1. 【0015】 6. The inorganic fine particles are silica particles, and is characterized by the toner for electrostatic charge image development according to item 1. 【0016】 7. A developer which is a mixture of electrostatic image developing toner and carrier as described in any one of paragraphs 1 to 6. 【0017】 8. An image forming method comprising a development step in which development is performed using an electrostatic image developing toner described in any one of paragraphs 1 to 6. [Effects of the Invention] 【0018】 The present invention provides a toner, developer, and image forming method for electrostatic image development that can suppress development leakage and reduce image density fluctuations. 【0019】 Although the mechanism of action or mechanism of the present invention is not yet clear, it is speculated as follows. 【0020】 Free components are surface modifiers released from external additives. By keeping the content of free components within a specific range, the decrease in carrier charging performance caused by excessive free components can be suppressed. This suppresses image density fluctuations. Also, by keeping the content of free components within a specific range, the fluctuation in resistance due to wear of the coating resin covering the carrier caused by excessive free components can be suppressed. This suppresses the decrease in carrier resistance and thus suppresses development leakage. Development leakage originates from the discharge that occurs between the photoreceptor and the carrier magnetic brush. Furthermore, by keeping the molecular weight of the free components within a specific range, charge fluctuations can be suppressed without significantly reducing the chargeability of the free components. In addition, by keeping the molecular weight of the free components within a specific range, the free components spread evenly and uniformly on the carrier surface, suppressing the decrease in carrier resistance. [Brief explanation of the drawing] 【0021】 [Figure 1] This is a flowchart showing the image forming method of this embodiment. [Figure 2]This is a schematic diagram showing a cross-section of the image forming apparatus used in the image forming method of this embodiment. [Modes for carrying out the invention] 【0022】 1. Toner for developing electrostatic images One embodiment of the electrostatic image developing toner of the present invention is an electrostatic image developing toner having toner matrix particles and an external additive. In this embodiment, the external additive of the electrostatic image developing toner contains at least inorganic fine particles, and these inorganic fine particles have a surface modifier on their surface. The weight-average molecular weight of the free components is 1000 or more and 20000 or less, and the content of the free components is 2 ppm or more and 700 ppm or less. The free components are chloroform extracts from methyl ethyl ketone insoluble matter extracted with methanol from the electrostatic image developing toner of this embodiment. Hereinafter, "the electrostatic image developing toner of this embodiment" may also be referred to as "the toner of this embodiment" or "toner". 【0023】 The electrostatic image developing toner of this embodiment, having the above-described configuration, exhibits the following effects when used as a developer, which is a mixture with a carrier. Specifically, because the weight-average molecular weight of the free components is 1000 or more, the surface modifier can be maintained on the surface of the inorganic fine particles during the toner manufacturing process, and the free components can be transferred to the carrier. The free components are the surface modifier that has been released from the surface of the inorganic fine particles. Furthermore, because the molecular weight of the free components is 20000 or less, the free components transferred to the carrier surface can suppress charge fluctuations without significantly reducing the charging performance of the carrier. In addition, the free components spread evenly and uniformly on the carrier surface, which can suppress the reduction of the carrier's resistance. It is preferable to adjust the viscosity of the surface modifier in order to make the weight-average molecular weight of the free components between 1000 and 20000. 【0024】 Furthermore, because the amount of free components is 2 mg / kg or more, the migration of free components to the carrier surface can suppress the reduction in resistance due to wear of the "coating resin covering the carrier." Also, because the amount of free components is 700 mg / kg or less, the free components that migrate to the carrier surface can suppress charge fluctuations without significantly reducing the charging performance of the carrier. It is preferable to adjust the amount of surface modifier and drying conditions in order to set the free component content between 2 mg / kg and 700 mg / kg. 【0025】 <Toner matrix particles> In the electrostatic image developing toner of this embodiment, the toner matrix particles preferably contain a binder resin, a release agent, a colorant, etc. They may also contain a charge control agent. Hereinafter, "toner matrix particles" may simply be referred to as "matrix particles." The matrix particles may contain other components as needed. 【0026】 [Binding resin] The binder resin constituting the matrix particles contained in the electrostatic image developing toner of this embodiment can be any known amorphous resin. Examples of amorphous resins include vinyl resin, urethane resin, urea resin, and polyester resin. Among these, polyester resin is preferred. By using polyester resin, the mechanical strength and toughness (toughness) of the toner can be increased, suppressing the embedding of external additives and increasing the probability of contact between the carrier and external additives, making it easier for free inorganic fine particles to migrate. On the other hand, in order to increase the mechanical strength of the toner to accommodate higher speeds, it is more preferable to use vinyl resin in combination. 【0027】 The vinyl resin is not particularly limited as long as it is a polymer of a vinyl compound, but examples include (meth)acrylic acid ester resin, styrene-(meth)acrylic acid ester resin, and ethylene-vinyl acetate resin. These may be used individually or in combination of two or more. Among the above vinyl resins, styrene-(meth)acrylic acid ester resin is preferred when considering plasticity during heat fixing. The following describes styrene-(meth)acrylic acid ester resin as an amorphous resin. Styrene-(meth)acrylic acid ester resin is also called "styrene-(meth)acrylic resin". Styrene-(meth)acrylic resin is formed by addition polymerization of at least a styrene monomer and a (meth)acrylic acid ester monomer. The styrene monomer referred to here includes not only styrene represented by the structural formula CH2=CH-C6H5, but also structures having known side chains or functional groups in the styrene structure. The (meth)acrylic acid ester monomer referred to here includes acrylic acid ester compounds and methacrylic acid ester compounds represented by CH2=CHCOOR (R is an alkyl group). Furthermore, (meth)acrylic acid monomers include ester compounds having known side chains or functional groups in the structure of acrylic acid ester derivatives and methacrylic acid ester derivatives. In this specification, "(meth)acrylic acid monomer" refers collectively to "acrylic acid monomer" and "methacrylic acid monomer". 【0028】 Examples of styrene monomers and (meth)acrylic acid ester monomers capable of forming styrene-(meth)acrylic resins are shown below. Specific examples of styrene monomers include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, and pn-dodecylstyrene. These styrene monomers can be used individually or in combination of two or more. 【0029】 Furthermore, specific examples of (meth)acrylic acid ester monomers include, for example, acrylic acid ester monomers such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, and phenyl acrylate; and methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, and dimethylaminoethyl methacrylate. These (meth)acrylic acid ester monomers can be used individually or in combination of two or more types. 【0030】 The weight-average molecular weight (Mw) of the styrene-(meth)acrylic resin is preferably 10,000 to 100,000. The method for producing the styrene-(meth)acrylic resin is not particularly limited, and includes methods using any polymerization initiator commonly used for polymerization of the above monomer and polymerization by known polymerization methods. Examples of polymerization initiators include peroxides, persulfides, persulfates, and azo compounds. Examples of polymerization methods include bulk polymerization, solution polymerization, emulsion polymerization, miniemulsion polymerization, and dispersion polymerization. In addition, commonly used chain transfer agents can be used to adjust the molecular weight. Examples of chain transfer agents are not particularly limited, and include alkyl mercaptans such as n-octyl mercaptan and mercapto fatty acid esters. 【0031】 The polyester resin constituting the above-mentioned binder resin is produced by polycondensation reaction using polycarboxylic acid monomers (derivatives) and polyhydric alcohol monomers (derivatives) as raw materials, in the presence of an appropriate catalyst. Examples of polycarboxylic acid monomer derivatives include alkyl esters, acid anhydrides, and acid chlorides of polycarboxylic acid monomers. Examples of polyhydric alcohol monomer derivatives include ester compounds and hydroxycarboxylic acids of polyhydric alcohol monomers. Examples of polycarboxylic acid monomers include oxalic acid, succinic acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, malonic acid, pimelic acid, tartaric acid, mucoic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p Examples of divalent carboxylic acids include -phenylenediacetic acid, m-phenylenediglycolic acid, p-phenylenediglycolic acid, o-phenylenediglycolic acid, diphenylacetic acid, diphenyl-p,p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracenedicarboxylic acid, and dodecenylsuccinic acid; and trivalent or higher carboxylic acids such as trimellitic acid, pyromellitic acid, naphthalentricarboxylic acid, naphthalenetetracarboxylic acid, pyrentricarboxylic acid, and pyrenetetracarboxylic acid. As polyvalent carboxylic acid monomers, it is preferable to use unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid, and mesaconic acid. In addition, in the present invention, anhydrides of dicarboxylic acids such as maleic anhydride can also be used. 【0032】 Examples of polyhydric alcohol monomers include dihydric alcohols such as ethylene glycol, propylene glycol, butanediol, diethylene glycol, hexanediol, cyclohexanediol, octanediol, decanediol, dodecanediol, ethylene oxide adducts of bisphenol A, and propylene oxide adducts of bisphenol A; and trihydric or higher polyols such as glycerin, pentaerythritol, hexamethylolmelamine, hexaethylolmelamine, tetramethylolbenzoguanamine, and tetraethylolbenzoguanamine. 【0033】 [Release agent] Various known waxes can be used as release agents. Examples of waxes include polyolefin waxes such as polyethylene wax and polypropylene wax, branched hydrocarbon waxes such as microcrystalline wax, long-chain hydrocarbon waxes such as paraffin wax and sazole wax, dialkylketone waxes such as distearyl ketone, carnauba wax, montane wax, behenate behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanediol distearate, ester waxes such as tristearyl trimellitate and distearyl maleate, and amide waxes such as ethylenediamine behenylamide and tristearyl trimellitate. From the viewpoint of fixation, hydrocarbon waxes are preferred. 【0034】 The release agent content is preferably 0.1 to 30 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the binder resin. These can be used individually or in combination of two or more types. Furthermore, the melting point of the release agent is preferably 50 to 95°C from the viewpoint of low-temperature fixation and release properties of toner in electrophotography. 【0035】 [Charge control agent] Various known charge control agents are preferred, and those that can be dispersed in an aqueous medium are preferred. Specifically, examples include nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, metal salicylates, and metal salicylate complexes. The charge control agent is preferably in particulate form. 【0036】 An embodiment in which no charge control agent is contained is also a preferred embodiment. If a charge control agent is contained, the content of the charge control agent is preferably in the range of 0.1 to 10% by mass relative to the total mass of the binder resin. 【0037】 Furthermore, the particle size of the charge control agent is preferably in the range of 10 to 1000 nm, more preferably in the range of 50 to 500 nm, and particularly preferably in the range of 80 to 300 nm, based on the number-average primary particle size. 【0038】 [Coloring agent] The electrostatic image developing toner of this embodiment can also be used as a magnetic toner, but from the viewpoint of achieving the effects of the present invention, it is preferable to use it as a non-magnetic toner. Furthermore, it is preferable to use the electrostatic image developing toner of this embodiment as a color toner by incorporating a coloring agent. 【0039】 As a coloring agent, dyes, pigments, carbon black, magnetic materials, etc., can be used as desired. Among these, dyes or pigments are preferred from the viewpoint of being usable as a color toner. 【0040】 Examples of dyes include CI Solvent Red 1, 49, 52, 58, 63, 111, 122; CI Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162; CI Solvent Blue 25, 36, 60, 70, 93, 95, etc. These can be used individually or in combination of two or more. 【0041】 Examples of pigments include CI Pigment Red 5, 48:1, 48:3, 53:1, 57:1, 81:4, 122, 139, 144, 149, 166, 177, 178, 222; CI Pigment Orange 31, 43; CI Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, 185; CI Pigment Green 7; CI Pigment Blue 15:3, 15:4, 60, etc. These can be used individually or in combination of two or more. 【0042】 Examples of colorants for white include inorganic pigments and organic pigments. Examples of inorganic pigments include titanium white, zinc white, titanium strontium white, heavy calcium carbonate, light calcium carbonate, titanium dioxide, aluminum hydroxide, satin white, talc, calcium sulfate, barium sulfate, zinc oxide, magnesium oxide, magnesium carbonate, amorphous silica, colloidal silica, white carbon, kaolin, calcined kaolin, delaminated kaolin, aluminosilicate, sericite, bentonite, and smexite. Examples of organic pigments include polystyrene resin particles and urea phorimarin resin particles. 【0043】 Examples of carbon black include channel black, furnace black, acetylene black, thermal black, or lamp black. 【0044】 Examples of magnetic materials include ferromagnetic metals such as iron, nickel, and cobalt, as well as alloys containing these metals, and compounds of ferromagnetic metals such as ferrite and magnetite. 【0045】 The amount of colorant is not particularly limited, but from the viewpoint of ensuring color reproduction of the image, it is preferably in the range of 1 to 30% by mass, and more preferably in the range of 2 to 20% by mass, relative to the total mass of the toner matrix particles. 【0046】 Furthermore, the particle size of the coloring agent is preferably in the range of 10 to 1000 nm, more preferably in the range of 50 to 500 nm, and even more preferably in the range of 80 to 300 nm, in terms of volume-average particle size. 【0047】 <External additives> In this embodiment, the toner for developing electrostatic images preferably has an external additive on the surface of the toner matrix particles. The external additive includes at least inorganic fine particles. The inorganic fine particles have a surface modifier on their surface. In addition, the toner matrix particles may contain organic fine particles, lubricants, etc., as external additives, in addition to inorganic fine particles. Furthermore, the toner for developing electrostatic images in this embodiment has a free component which is a chloroform extract from the methyl ethyl ketone insoluble matter extracted from the toner for developing electrostatic images. 【0048】 [Inorganic fine particles] Examples of inorganic fine particles include silica fine particles, inorganic oxide fine particles such as aluminum oxide fine particles and titanium oxide fine particles, inorganic stearic acid compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, and inorganic titanate compound fine particles such as strontium titanate and zinc titanate. Aluminum oxide fine particles are alumina fine particles. From the viewpoint of obtaining the effects of the present invention more effectively, it is preferable that the inorganic fine particles are silica fine particles. Since silica fine particles with high negative charge repel each other electrically with PDMS with high negative charge, free components can be effectively transferred to the carrier. Furthermore, these inorganic fine particles may be subjected to gloss treatment, hydrophobic treatment, etc., using silane coupling agents, titanium coupling agents, higher fatty acids, silicone oils, etc., in order to improve heat resistance for storage, improve environmental stability, etc. 【0049】 From the viewpoint of more effectively obtaining the effects of the present invention, it is preferable that the number-average primary particle diameter of the inorganic fine particles is in the range of 15 to 100 nm. It is even more preferable that the number-average primary particle diameter of the inorganic fine particles is in the range of 20 to 60 nm. When the number-average primary particle diameter of the inorganic fine particles is 15 nm or more, even if there are some irregularities on the surface of the toner matrix particles, contact with the carrier particles becomes easier, so the silicone oil is more likely to migrate to the carrier particles and exhibit sufficient function. Furthermore, when the number-average primary particle diameter of the inorganic fine particles is 100 nm or less, it becomes easier to secure a sufficient amount of inorganic fine particles on the surface of the toner matrix particles, so the silicone oil is more likely to migrate to the carrier particles and exhibit sufficient function. 【0050】 The number-average primary particle size of inorganic microparticles can be measured by the following method: Using a scanning electron microscope (SEM) "JEM-7401F" (manufactured by JEOL Ltd.), an SEM image of the toner magnified 30,000 times is taken, and the particle size (Ferret diameter) of the primary silica particles is measured by observing the SEM image. Then, the number-average primary particle size is calculated by dividing the sum of these values ​​by the number of particles. The particle size measurement is performed by selecting an area in the SEM image where the total number of particles is approximately 100 to 200. 【0051】 The amount of inorganic fine particles added is preferably 0.1 to 2 parts by mass per 100 parts by mass of toner, and more preferably 0.5 to 1.8 parts by mass. An amount of 0.1 parts or more provides a sufficient quantity to be uniformly distributed on the toner surface. An amount of 2 parts by mass or less allows for appropriate adjustment of the amount transferred to the carrier. 【0052】 The amount of free components is preferably 200 to 10,000 mg / kg relative to inorganic fine particles, and more preferably 200 to 8,000 mg / kg. By setting it to 200 mg / kg or more, the silicone oil migrates to the carrier surface, which can suppress the reduction in resistance due to wear of the coating resin. By setting it to 10,000 mg / kg or less, the silicone oil that migrates to the carrier surface can suppress charge fluctuations without significantly reducing the carrier's charging ability. 【0053】 (Surface modifier) As surface modifiers, general coupling agents, silane compounds, silicone oils, fatty acids, fatty acid metal salts, etc., can be used. Among these, silane compounds and silicone oils are preferred. Examples of silane compounds include chlorosilane, alkoxysilane, silazane, and special silylating agents. Specifically, as surface modifiers, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N,O-(B Examples of typical examples include strimethylsilyl acetamide, N,N-bis(trimethylsilyl)urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane. 【0054】 Specific examples of silicone oils include, for instance, dimethyl silicone oil, alkyl-modified silicone oil, amino-modified silicone oil, carboxyl-modified silicone oil, epoxy-modified silicone oil, fluorine-modified silicone oil, alcohol-modified silicone oil, polyether-modified silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, mercapto-modified silicone oil, higher fatty acid-modified silicone oil, phenol-modified silicone oil, methacrylic acid-modified silicone oil, polyether-modified silicone oil, and methylstyryl-modified silicone oil. Furthermore, the silicone oil used for surface modification may be used alone or in combination of two or more types. 【0055】 Surface modification methods include, for example, dry methods, wet methods, and mixing methods. Dry methods include spray drying, in which a treatment agent or a solution containing the treatment agent is sprayed onto particles suspended in the gas phase. Wet methods involve immersing particles in a solution containing the treatment agent and then drying them. Mixing methods involve mixing the treatment agent and particles using a mixer. 【0056】 The free component of inorganic fine particles is preferably silicone oil from the viewpoint of insulation. Methods for incorporating the free component of inorganic fine particles into the toner include, for example, incorporating it into the toner as a surface modifier of the inorganic fine particles, adding it to the inorganic fine particles, or adding it to the toner particles. Among these, incorporating it into the inorganic fine particles is preferred. Furthermore, in order to effectively supply it to the carrier surface, it is preferable to use silicone oil as the surface modifier of the inorganic fine particles. 【0057】 [Organic fine particles] As organic microparticles, for example, spherical organic microparticles with a number-average primary particle diameter of about 10 to 2000 nm can be used. Specifically, organic microparticles made from homopolymers such as styrene and methyl methacrylate, or copolymers thereof, can be used. 【0058】 [Lubricant] Lubricants are used to further improve cleaning and transfer properties. Examples of lubricants include metal salts of higher fatty acids. Specific examples of metal salts of higher fatty acids include: salts of stearate with zinc, aluminum, copper, magnesium, and calcium; salts of oleate with zinc, manganese, iron, copper, and magnesium; salts of palmitate with zinc, copper, magnesium, and calcium; salts of linoleate with zinc and calcium; and salts of ricinoleate with zinc and calcium. 【0059】 <Free fraction> The free component is the chloroform extract from the methyl ethyl ketone insoluble matter extracted with methanol from the electrostatic image developing toner of this embodiment. In other words, the electrostatic image developing toner of this embodiment is extracted with methanol, and solid component 1 is taken out from the resulting methanol solution. Then, the components that dissolve in methyl ethyl ketone are removed from the obtained solid component 1 to obtain solid component 2. The obtained solid component 2 is extracted with chloroform, and solid component 3 is taken out from the resulting chloroform solution. The obtained solid component 3 is the free component. 【0060】 Specific methods for obtaining free components from the electrostatic image developing toner of this embodiment include, for example, the following methods. Note that the mass, volume, etc., of each substance are not limited to the specific values ​​below, nor are the instruments, devices, and conditions used limited to the specific instruments, devices, and conditions below. 【0061】 Place 3g of toner in a 50mL screw-cap vial, wet it with 40g of methanol, and stir. Then, transfer it to a 60mL disposable cup and adjust the ultrasonic homogenizer "US-1200T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.) so that the φ36 tip of the ultrasonic transducer is immersed in the liquid to about 3cm. Then, adjust the ultrasonic energy to 100W and apply ultrasound for 1 minute to obtain a dispersion. Transfer the obtained dispersion to a 15mL test tube and collect the supernatant after standing overnight. Repeat the above process from 3g of toner to collecting the supernatant. Concentrate the collected supernatant completely to dryness. Reflux the solid obtained by concentration to dryness with methyl ethyl ketone to remove the methyl ethyl ketone-soluble components and obtain a solid sample. Specifically, for example, after the above reflux, separate the solid components by ultra-cooled centrifugation to obtain a solid sample. Weigh the obtained solid sample in a 50mL glass centrifuge tube. Then, 20 mL of chloroform is added to the centrifuge tube, and ultrasonic waves are applied for 10 minutes using the ultrasonic homogenizer described above. After that, centrifugation is performed at 3500 rpm for 10 minutes. The clear supernatant obtained by centrifugation is transferred to a 100 mL round-bottom flask and dried under reduced pressure. The solid obtained by drying under reduced pressure is weighed in a 50 mL glass centrifuge tube, and the above procedure is repeated to obtain the free component. When performing GPC measurement on the obtained free component, 2 mg of the free component is weighed, 2 mL of toluene is added dropwise, and the mixture is filtered through a membrane filter with a pore size of 0.2 μm to prepare the GPC measurement sample solution. 【0062】 The weight-average molecular weight of the free components is between 1,000 and 20,000. Preferably, the weight-average molecular weight of the free components is between 1,000 and 15,000, more preferably between 1,000 and 10,000, and particularly preferably between 2,000 and 10,000. It is preferable to adjust the viscosity of the surface modifier in order to achieve a weight-average molecular weight of 1,000 and 20,000 or less for the free components. 【0063】 The weight-average molecular weight of the free component is the weight-average molecular weight corresponding to the main peak obtained by GPC measurement using a toluene solution of the free component as the measurement sample. GPC is gel permeation chromatography. The weight-average molecular weight also corresponds to the area of ​​the main peak. Here, "peak" refers to the region that forms a maximum or minimum in the region of the elution curve excluding the solvent elution range. And "peak area" refers to the area of ​​the region that protrudes to the positive or negative side relative to the baseline. In this specification, a "peak" is defined as having an area of ​​3% or more of the total peak area of ​​the elution curve obtained by the above GPC measurement. The peak obtained by GPC measurement is the peak in the elution curve with time on the horizontal axis and detection intensity on the vertical axis. The above main peak is the peak with the largest detection intensity among the peaks in the elution curve. If the main peak and other peaks overlap, a perpendicular line is drawn from the point where the curves intersect to the horizontal axis, and the two peaks are separated into the main peak side and the other peak side at this perpendicular line, and the weight-average molecular weight of the main peak side is calculated. 【0064】 When a silicone oil is used as the surface modifier, the free component will also be silicone oil. When the free component is silicone oil, the elution curve obtained by GPC measurement may show a peak on the negative side. In this case, the main peak is a "downward-facing peak" with a minimum value, and the peak with the largest detection intensity on the negative side. The largest detection intensity on the negative side means that the absolute value of the detection intensity is the largest. 【0065】 When performing GPC measurement, the free component is dissolved in toluene to prepare a toluene solution, and the toluene solution of the free component is used as the measurement sample. By using the toluene solution of the free component as the sample for GPC measurement, the sensitivity of GPC measurement can be increased. Especially when the free component is silicone, the refractive index difference between toluene and silicone is large, enabling high-sensitivity measurement. The weight-average molecular weight can be calculated from the results of GPC measurement using the calibration curve of standard polystyrene. As the GPC measurement device, for example, HLC-8420GPC (manufactured by Tosoh Corporation) can be used. Also, as the column, for example, Shodex K-806M (manufactured by Resonac) can be used. As the conditions for GPC measurement, while maintaining the column temperature at 45°C, HPLC-grade toluene is used as the carrier solvent and flowed at a flow rate of 1.0 mL / min. Then, together with the carrier solvent, 200 μL of the prepared sample solution is injected into the GPC and detected using a differential refractive index detector (RI detector). The calibration curve is created by measuring 11 standard polystyrenes (manufactured by Agilent) and n-hexylbenzene (manufactured by Tokyo Chemical Industry Co., Ltd.) with molecular weights of 5.80×10 2 、1.25×10 3 、4.91×10 3 、9.82×10 3 、2.29×10 4 、6.76×10 4 、2.17×10 5 、5.37×10 5 、9.20×10 5 、3.15×10 6 、6.57×10 6 respectively. The GPC device, column, and standard polystyrene are not limited to these as long as they have equivalent performance. 【0066】 When the weight-average molecular weight of the free components is Mw and the number-average molecular weight of the free components is Mn, it is preferable that the Mw / Mn value is between 1 and 3. When the Mw / Mn value is 1 or greater, there are components with a relatively low molecular weight, so the free components spread uniformly across the carrier surface. Furthermore, when the Mw / Mn value is 3 or less, the electrical properties of the free components become somewhat uniform, so uniform electrical properties can be maintained on the carrier surface. 【0067】 The number-average molecular weight of the free components is the number-average molecular weight corresponding to the main peak obtained by GPC measurement using a toluene solution of the free components as the measurement sample. The measurement method is the same as the weight-average molecular weight measurement method described above, but the number average is calculated instead of the weight average. 【0068】 The free component content is preferably 2 mg / kg or more and 700 mg / kg or less. More preferably, the free component content is 2 mg / kg or more and 500 mg / kg or less. The free component content is the amount of free component extracted from the toner as described above relative to the total amount of toner, and is expressed as the mass (mg) of free component per 1 kg of toner. Since the free component obtained by extraction from the toner may contain impurities, it is preferable to determine the accurate mass of the free component by performing GPC measurement. The free component content can be obtained by GPC measurement using polydimethylsiloxane as a standard. More specifically, a polydimethylsiloxane solution of known concentration can be measured by GPC and determined by the absolute calibration curve method or standard addition method using the polydimethylsiloxane as a standard. A commercially available polydimethylsiloxane (e.g., Sigma-Aldrich 181846-25G) or an equivalent reagent may be used. To ensure that the free content is between 2 mg / kg and 700 mg / kg, it is preferable to adjust the amount of surface modifier and the drying conditions. 【0069】 2. Developer One embodiment of the developer of the present invention is a mixture of the electrostatic image developing toner of the above embodiment and a carrier. Since the developer of this embodiment is a mixture of the electrostatic image developing toner of the above embodiment and a carrier, it can produce the effects of the electrostatic image developing toner of the above embodiment. The content of the electrostatic image developing toner in the developer is preferably in the range of 5 to 10% by mass of the total mass of the developer. This makes it possible to effectively bring out the above effects of the electrostatic image developing toner. 【0070】 <Career> In the developer of this embodiment, the carrier is an aggregate of carrier particles. The carrier particles are magnetic particles that, when stirred together with the toner, can impart a desired amount of charge to the toner and can also transport the charged toner to the surface of the photoreceptor. After transporting the toner to the surface of the photoreceptor, the carrier returns to the developer, is mixed and stirred with new toner, and is used repeatedly for a certain period of time. 【0071】 Examples of carrier particle configurations include coated carrier particles in which the surface of core material particles made of a magnetic material is coated with a resin or the like, and resin-dispersed carrier particles in which fine magnetic powder is dispersed in a resin. From the viewpoint of suppressing the adhesion of carrier particles to the photoreceptor, coated carrier particles are preferred. 【0072】 The volume-average particle size of the carrier particles is preferably in the range of 10 to 100 μm, and more preferably in the range of 20 to 80 μm. The volume-average particle size of the carrier particles can be measured using a laser diffraction particle size distribution analyzer "HELOS" (manufactured by Sympathic Co., Ltd.) equipped with a wet disperser. 【0073】 [Core material particles] The core material particles are magnetic particles, and examples of magnetic particles include iron powder, magnetite, various ferrite particles, and particles in which these are dispersed in resin. These may be used individually or in combination of two or more types. 【0074】 Among these, ferrite particles are preferred as magnetic particles. Since ferrite particles have a specific gravity lower than that of the constituent metals, the agitation impact force in the developing unit can be reduced. Examples of ferrite include ferrite containing heavy metals such as copper, zinc, nickel, and manganese, and ferrite containing light metals such as alkali metals or alkaline earth metals. 【0075】 Furthermore, it is preferable that the core material particles contain strontium (Sr). By including strontium, the surface irregularities of the core material particles can be increased, making it easier for the surface of the core material particles to be exposed even when the surface of the core material particles is coated with resin or the like, and thus easier to adjust the carrier resistance. 【0076】 [Coating layer] As described above, the coating layer is a layer that covers the surface of the core material particles. The coating material that covers the surface of the core material particles is not particularly limited, but it is preferably a resin. Suitable resins for use as a coating material for forming the carrier coating layer include polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, and chlorosulfonated polyethylene; polystyrene, polyacrylates such as polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinylcarbazole, polyvinyl ether, and polypyriketone; copolymers such as vinyl chloride-vinyl acetate copolymer and styrene-acrylic acid copolymer; silicone resins or modified resins thereof consisting of organosiloxane bonds; fluororesins such as polytetrachloroethylene, polyvinyl fluoride, polyvinylidene fluoride, and polychlorotrifluorylene; polyamides; polyesters; polyurethanes; polycarbonates; amino resins such as urea-formaldehyde resins; and epoxy resins. The above-mentioned modified resin is, for example, a modified resin made from alkyd resin, polyester resin, epoxy resin, polyurethane, etc. 【0077】 Among these, polyacrylate resins are particularly preferred. In particular, resins formed from alicyclic methacrylate monomers have high hydrophobicity, which allows free components that migrate to the carrier to easily wet the surface, enabling efficient supply of free components to the carrier. From the viewpoint of mechanical strength, charge stability, ease of polymerization, and availability, the alicyclic methacrylate monomer is preferably a cycloalkyl group having 5 to 8 carbon atoms. Here, excellent charge stability means that the environmental difference in charge is small. The alicyclic methacrylate monomer is preferably at least one selected from the group consisting of cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate. Among these, it is preferable to include cyclohexyl (meth)acrylate from the viewpoint of mechanical strength and environmental stability of charge. 【0078】 A copolymer of an alicyclic methacrylate monomer and a chain-type methacrylate monomer is more preferable as the resin used to form the carrier coating layer. In particular, methyl methacrylate is preferred because it further increases the film strength. Furthermore, it is more preferable that the composition ratio includes 30% by mass or more of the alicyclic methacrylate monomer. When it is 30% by mass or more, an appropriate film strength is obtained, making it easier to obtain the effects of the present invention. 【0079】 3. Method for manufacturing toner for electrostatic image development. The method for producing the electrostatic image developing toner of this embodiment is not particularly limited, and known methods such as the kneading and grinding method, suspension polymerization method, emulsification and agglutination method, dissolution and suspension method, polyester stretching method, and dispersion polymerization method can be used. Among these, the emulsification and agglutination method is preferred from the viewpoint of uniformity of particle size and controllability of shape. 【0080】 The toner of this embodiment can be manufactured by a manufacturing method that specifically includes the following procedure. However, this is merely an example, and the manufacturing method of the toner of this embodiment is not limited to the following method. 【0081】 The emulsification and agglomeration method in the toner manufacturing method of this embodiment involves first mixing a dispersion of binder resin particles dispersed with a surfactant and a dispersion stabilizer with a dispersion of colorant particles as needed, and agglomerating until the desired toner particle size is achieved. Then, the shape is controlled by fusing the binder resin particles together. Hereinafter, the binder resin particles will also be referred to as "binding resin particles," and the colorant particles will also be referred to as "colorant particles." The binder resin particles may optionally contain a mold release agent, a charge control agent, etc. 【0082】 An example of a preferred method for manufacturing the toner of this embodiment is shown below, in which toner particles containing a colorant and having a core-shell structure are obtained using an emulsification and agglutination method. This manufacturing method includes the following steps (1) to (7). 【0083】 (1) A step of preparing a coloring agent particle dispersion in which coloring agent particles are dispersed in an aqueous medium. (2) A process to prepare a binder resin particle dispersion (for core particles / shell layer binder resin particle dispersion) in which binder resin particles containing internal additives (release agent, charge control agent, etc., as needed) are dispersed in an aqueous medium. (3) A process to obtain a flocculation resin particle dispersion by mixing a colorant particle dispersion and a core particle binder resin particle dispersion, and to form flocculated particles as core particles by flocculating and fusing the colorant particles and core particle binder resin particles in the presence of a flocculant (flocculation and fusing process). (4) A process to form toner matrix particles with a core-shell structure by adding a shell layer binder resin particle dispersion containing shell layer binder resin particles to a dispersion containing core particles, thereby agglomerating and fusing the shell layer binder resin particles to the surface of the core particles (aggregation and fusing process). (5) A process to filter out toner matrix particles from the toner matrix particle dispersion (toner matrix particle dispersion) and remove surfactants, etc. (filtration and washing process) (6) Drying process for toner matrix particles (drying process) (7) A step of obtaining toner for electrostatic image development by adding an external additive to toner matrix particles (external additive treatment step) 【0084】 Toner particles having a core-shell structure are first produced by agglomerating and fusing binder resin particles for the core particles with colorant particles to create core particles. Next, binder resin particles for the shell layer are added to a dispersion of core particles to agglomerate and fuse the binder resin particles for the shell layer onto the surface of the core particles, thereby forming a shell layer that covers the surface of the core particles. However, toner particles formed from single-layer particles can also be produced in the same manner by, for example, omitting the addition of the binder resin particle dispersion for the shell layer in step (4) above. 【0085】 In the present invention, "aqueous medium" refers to a medium composed of 50 to 100% by mass of water and 0 to 50% by mass of a water-soluble organic solvent. Examples of water-soluble organic solvents include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. It is preferable that the organic solvent is an alcohol-based organic solvent that does not dissolve the resulting resin. 【0086】 (1) A step of preparing a coloring agent particle dispersion in which coloring agent particles are dispersed in an aqueous medium. A dispersion of colorant particles can be prepared by dispersing a colorant in an aqueous medium. From the viewpoint of uniform dispersion, it is preferable to perform the dispersion of the colorant in an aqueous medium with a surfactant concentration equal to or greater than the critical micelle concentration (CMC). Various known dispersers can be used for the dispersion of colorants. 【0087】 (Surfactants) Examples of surfactants include anionic surfactants such as alkyl sulfate esters, polyoxyethylene (n) alkyl ether sulfates, alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters; cationic surfactants of the amine salt type such as alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, and imidazolines, as well as quaternary ammonium salt types such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, and benzethonium chloride; nonionic surfactants such as fatty acid amide derivatives and polyhydric alcohol derivatives; and amphoteric surfactants such as alanine, dodecyldi(aminoethyl)glycine, di(octylaminoethyl)glycine, and N-alkyl-N,N-dimethylammonium betaine. Anionic and cationic surfactants having fluoroalkyl groups can also be used. 【0088】 In this process, the dispersion diameter of the colorant particles in the prepared colorant particle dispersion is preferably in the range of 10 to 300 nm in terms of volume-based median diameter. The volume-based median diameter of the colorant particles contained in the colorant particle dispersion can be measured using the electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.). 【0089】 The coloring agent may be introduced into the toner matrix particles by dissolving or dispersing it in a monomer solution for forming the resin beforehand using the miniemulsion method in the binder resin particle dispersion preparation step described later. 【0090】 (2) A process to prepare a binder resin particle dispersion (for core particles / shell layer binder resin particle dispersion) in which binder resin particles containing internal additives (release agent, charge control agent, etc., as needed) are dispersed in an aqueous medium. Methods for dispersing binder resins in an aqueous medium include direct aqueous dispersion, dissolution-emulsification-desolvation, and phase inversion emulsification. Direct aqueous dispersion involves dispersing the binder resin in an aqueous medium to which a surfactant has been added, using methods such as ultrasonic dispersion or bead mill dispersion. Dissolution-emulsification-desolvation involves dissolving the binder resin in a solvent, dispersing it in an aqueous medium to form emulsion particles (oil droplets), and then removing the solvent. 【0091】 In this process, the average particle size of the resulting binder resin particles is preferably in the range of 50 to 500 nm, for example, based on the volume-based median diameter. The volume-based median diameter was measured using a "UPA-EX150" (manufactured by Microtrac-Bell). 【0092】 When the binder resin is amorphous vinyl resin, first, a solution containing polymerizable monomers for forming amorphous vinyl resin, along with, if necessary, release agents and charge control agents, which constitute the toner matrix particles, is added to an aqueous medium containing a surfactant at or below the critical micelle concentration (CMC). Mechanical energy is then applied to form droplets. Next, a water-soluble radical polymerization initiator is added to allow the polymerization reaction to proceed within the droplets, thereby preparing a dispersion of binder resin (amorphous vinyl resin) particles. The droplets may also contain a hydrophobic polymerization initiator. 【0093】 In this process, a process of emulsifying (forming droplets) by applying mechanical energy is essential. Means of applying mechanical energy include homomixers, ultrasonic devices, mantongorins, and other means of strong stirring or ultrasonic vibration energy application. 【0094】 In this process, the binder resin particles can also consist of two or more layers made of resins with different compositions. In this case, a method can be used in which a polymerization initiator and a polymerizable monomer are added to a dispersion of resin particles prepared by emulsion polymerization treatment (first-stage polymerization) according to a conventional method, and this system is further polymerized (second-stage polymerization, third-stage polymerization). 【0095】 Furthermore, if a surfactant is used, the same type as the surfactant mentioned above can be used. 【0096】 (Polymerization initiator) The polymerization initiator is not particularly limited and known ones can be used. Examples of polymerization initiators include hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetraline hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetate-tert-hydroperoxide, tert-butyl performate, and ter peracetic acid. Examples include peroxides such as t-butyl, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, and tert-butyl perN-(3-toluyl)palmitate; and azo compounds such as 2,2'-azobis(2-amidinopropane) hydrochloride, 2,2'-azobis-(2-amidinopropane) nitrate, 1,1'-azobis(1-methylbutyronitrile-3-sodium sulfonate), 4,4'-azobis-4-cyanovaleric acid, and poly(tetraethylene glycol-2,2'-azobisisobutyrate). 【0097】 In particular, water-soluble polymerization initiators, such as ammonium persulfate, sodium persulfate, potassium persulfate, hydrogen peroxide, 2,2'-azobis(2-amidinopropane) hydrochloride, 2,2'-azobis-(2-amidinopropane) nitrate, 1,1'-azobis(1-methylbutyronitrile-3-sodium sulfonate), and 4,4'-azobis-4-cyanovaleric acid are preferred. 【0098】 Furthermore, redox polymerization initiators such as persulfates and metabisulfites, or hydrogen peroxide and ascorbic acid can also be used as polymerization initiators. 【0099】 (Chain transfer agent) In this process, particularly when amorphous vinyl resin is used as the binder resin, a commonly used chain transfer agent can be used to adjust the molecular weight of the resin. The chain transfer agent is not particularly limited and examples include alkyl mercaptans and mercapto fatty acid esters. 【0100】 In this process, the average particle size of the resulting binder resin particles is preferably in the range of 50 to 500 nm, for example, based on the volume-based median diameter. The volume-based median diameter can be measured using "UPA-EX150" (product name) (manufactured by Microtrac-Bel). 【0101】 (3) A process to obtain a resin particle dispersion for flocculation by mixing a colorant particle dispersion and a resin particle dispersion for core particles, and to form flocculated particles as core particles by flocculating and fusing the colorant particles and binder resin particles in the presence of a flocculant (flocculation and fusing process). This step involves agglomerating and fusing the colorant particles and binder resin particles contained in each dispersion formed in the above step in an aqueous medium. In this step, the binder resin particle dispersion and the colorant particle dispersion are added to the aqueous medium to agglomerate and fuse these particles. 【0102】 A specific method for agglomerating and fusing a dispersion of colorant particles and a dispersion of binder resin particles is as follows: First, a flocculant is added to an aqueous medium to a concentration above the critical flocculation concentration. Next, the medium is heated to a temperature above the glass transition temperature of the binder resin particles and above the melting peak temperature of the release agent. This promotes the salting out of the colorant particles and binder resin particles while simultaneously promoting their fusion. Once the particles have grown to the desired size, a flocculation inhibitor is added to stop particle growth, and heating is continued as needed to control the particle shape. 【0103】 In this method, it is preferable to minimize the standing time after adding the flocculant and quickly heat the material to a temperature above the glass transition temperature of the binder resin. The reason for this is not entirely clear, but it is because depending on the standing time after salting out, there is a concern that the particle aggregation state may fluctuate, leading to an unstable particle size distribution or changes in the surface properties of the fused particles. The time to raise the temperature is usually preferably within 30 minutes, and more preferably within 10 minutes. 【0104】 Furthermore, a heating rate of 1°C / min or higher is preferable. While there is no particular upper limit to the heating rate, it is preferable to keep it at 15°C / min or lower from the viewpoint of suppressing the generation of coarse particles due to the rapid progression of fusion. In addition, it is important to maintain the temperature of the reaction system for a certain period of time after the reaction system reaches a temperature above the glass transition temperature in order to continue the fusion. This allows for the effective progression of toner matrix particle growth and fusion, and ultimately improves the durability of the resulting toner. 【0105】 (Flocculant) The flocculant is not particularly limited, but is preferably a metal salt. Examples of metal salts include monovalent, divalent, and trivalent metal salts. Examples of monovalent metal salts include alkali metal salts such as sodium, potassium, and lithium. Examples of divalent metal salts include calcium, magnesium, manganese, and copper. Examples of trivalent metal salts include iron and aluminum. Specific examples of metal salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. Among these, divalent metal salts are more preferable because they can promote flocculation in small amounts and their flocculation properties are easily controlled. These may be used individually or in combination of two or more. 【0106】 If a surfactant is used, the same type as the surfactant described above can be used. 【0107】 (4) A process to form toner matrix particles with a core-shell structure by adding a shell layer resin particle dispersion containing binder resin particles for the shell layer to a dispersion containing core particles, thereby agglomerating and fusing the shell layer particles to the surface of the core particles (aggregation and fusing process). This process, similar to (3) "a process to form aggregated particles as core particles by agglomerating and fusing colorant particles and binder resin particles in the presence of a flocculant (aggregation and fusing process)", involves agglomerating and fusing particles for the shell layer onto the surface of the core particles to form toner matrix particles with a core-shell structure. 【0108】 (5) A step of filtering the toner matrix particles from the dispersion of toner matrix particles (toner matrix particle dispersion) to remove surfactants and the like (filtration and washing step), (6) A step of drying the toner matrix particles (drying step). Known methods can be used for the filtration, washing step and the drying step. 【0109】 (7) A step of obtaining toner for electrostatic image development by adding an external additive to toner matrix particles (external additive treatment step) This process involves adding and mixing an external additive to the dried toner matrix particles. 【0110】 One method for adding external additives is the dry method, in which powdered external additives are added to dried toner matrix particles and mixed. Mechanical mixing devices such as Henschel mixers, Nauter mixers, Turbuler mixers, and coffee mills can be used as mixing equipment. 【0111】 In particular, by using a mixing device that can apply shear force to the particles being processed, such as a Henschel mixer, and by extending the mixing time or increasing the rotational speed of the stirring blades, the external additive can be firmly attached to each toner matrix particle. 【0112】 Furthermore, when using multiple types of external additives, all external additives may be mixed with the toner matrix particles at once, or they may be mixed in multiple stages according to the type of external additive. 【0113】 4. Carrier manufacturing method A method for manufacturing coated carrier particles will be described. The method for manufacturing coated carrier particles involves forming a coating layer on core material particles, and includes wet coating and dry coating methods. In this embodiment of toner, the dry coating method is preferred. The following descriptions assume that the coating material is a resin. 【0114】 (Wet coating method) Examples of wet coating methods include the following: 【0115】 (1) Fluidized bed spray coating method A method for forming a coating layer by spraying a coating solution, prepared by dissolving a coating resin in a solvent, onto the surface of core material particles using a fluidized bed, and then drying it. 【0116】 (2) Immersion coating method A method for forming a coating layer by immersing core material particles in a coating solution prepared by dissolving a coating resin in a solvent, and then drying the solution. 【0117】 (3) Polymerization method A method for forming a coating layer, which involves immersing core material particles in a coating solution prepared by dissolving monomers constituting the coating resin in a solvent, and then applying heat or other means to carry out a polymerization reaction. 【0118】 (Dry coating method) The dry coating method involves applying coating resin particles to the surface of core material particles, and then applying mechanical impact force to melt or soften the coating resin particles attached to the surface of the core material particles, thereby fixing them in place and forming a coating layer. 【0119】 In detail, core material particles, coating resin, and, if necessary, low-resistance fine particles are rapidly stirred using a high-speed stirring mixer capable of applying mechanical impact force under non-heating or heated conditions, thereby repeatedly applying impact force to the mixture. This causes the coating resin to melt or soften and adhere to the surface of the core material particles, forming a coating layer. 【0120】 For coating conditions, when heating, the temperature is preferably in the range of 80 to 130°C. The air velocity that generates the impact force is preferably 10 m / s or more when heating, and preferably 5 m / s or less when cooling to suppress aggregation of carrier particles. The time for applying the impact force is preferably 20 to 60 minutes. 【0121】 Furthermore, by applying stress to the carrier particles during or after the resin coating process, the resin coating on the protrusions of the core material particles can be peeled off, exposing the core material particles to an appropriate degree, and thus the resistance of the carrier can be adjusted. 【0122】 In the resin coating process using the dry coating method, resin peeling can be induced by lowering the heating temperature to 60°C or below and using a high-speed shear mixer or similar device during cooling. 【0123】 After the resin coating process, the resin can be peeled off by using a device capable of forced stirring. Examples of such methods include stirring and mixing using a turbulent mill, ball mill, or vibratory mill. 【0124】 Furthermore, by applying heat and impact to the resin coating the core material particles, the resin coating on the convex parts of the core material particles can be moved to the concave parts, thereby exposing the core material particles to an appropriate extent. In this case, it is preferable to apply the impact for a longer period of time, specifically, 1.5 hours or more is preferable. 【0125】 5. Method for manufacturing developer The developer of this embodiment is obtained by mixing the toner of this embodiment with the carrier described above. The mixing apparatus used for mixing is not particularly limited and examples include a Nauter mixer, a W-cone type mixer, a V-type mixer, and the like. 【0126】 6.Image forming method One embodiment of the image forming method of the present invention is an image forming method having a development step in which development is performed using the electrostatic image developing toner of this embodiment. In the image forming method of this embodiment, it is preferable to use the electrostatic image developing toner of this embodiment as the developer of this embodiment for development. Figure 1 is a flowchart of the image forming method of this embodiment. In the image forming method of this embodiment, it is preferable to perform image formation in an electrophotographic manner using the developer of this embodiment. When the image forming method of this embodiment is an electrophotographic manner, it is preferable to have a charging step S01, an electrostatic image forming step S02, a development step S03, a transfer step S04, a fixing step S05, and a cleaning step S06, as shown in Figure 1. The charging step S01 is a step of charging the surface of the image holder. The electrostatic image forming step S02 is a step of forming an electrostatic image on the charged surface of the image holder. The development step S03 is a step of developing the electrostatic image formed on the surface of the image holder as a toner image. The transfer step S04 is a step of transferring the toner image formed on the surface of the image holder to the surface of the recording medium. The fixing process S05 is the process of fixing the toner image transferred to the surface of the recording medium. The cleaning process S06 is the process of cleaning the surface of the image holder. 【0127】 (Charging process) In this process, the electrophotographic photoreceptor is charged. The method of charging is not particularly limited, and known methods can be used, such as a charging roller system in which the electrophotographic photoreceptor is charged by a charging roller. 【0128】 (Electrostatic image formation process) In this process, an electrostatic image is formed on an electrophotographic photoreceptor (electrostatic image holder). 【0129】 The electrophotographic photoreceptor is not particularly limited, and examples include a drum-shaped one made of an organic photoreceptor such as polysilane or phthalopolymethine. 【0130】 The formation of an electrostatic image is carried out, for example, by uniformly charging the surface of an electrophotographic photoreceptor with a charging means and then exposing the surface of the electrophotographic photoreceptor with an exposure means in a manner that forms an image. The term "electrostatic image" refers to the image formed on the surface of an electrophotographic photoreceptor by such a charging means. 【0131】 The charging means and exposure means are not particularly limited, and methods known in electrophotography can be used. 【0132】 (Development process) In this process, the electrostatic image is developed with the developer of this embodiment to form a toner image. 【0133】 The toner image is formed using a developing means consisting of a stirrer that uses the developer of this embodiment to frictionally agitate and charge the toner of this embodiment, and a rotatable magnetic roller. 【0134】 Specifically, in the developing means, for example, the toner and carrier of this embodiment are mixed and stirred, and the friction during this process causes the toner of this embodiment to become charged and is held on the surface of a rotating magnetic roller, forming a magnetic brush. Since the magnetic roller is positioned near the electrophotographic photoreceptor, a portion of the toner of this embodiment that constitutes the magnetic brush formed on the surface of the magnetic roller moves to the surface of the electrophotographic photoreceptor by electrical attraction. As a result, a static charge image is developed by the toner of this embodiment, and a toner image is formed on the surface of the electrophotographic photoreceptor. 【0135】 (Transfer process) In this process, the toner image is transferred to the recording medium. 【0136】 The transfer of the toner image to the recording medium is performed by peeling and charging the toner image onto the recording medium. 【0137】 As a transfer method, for example, a corona discharge-based corona transfer device, a transfer belt, or a transfer roller can be used. 【0138】 Furthermore, the transfer process can be carried out in various ways, such as using an intermediate transfer medium to first transfer the toner image onto the intermediate transfer medium and then secondarily transfer this toner image onto the recording medium, or by directly transferring the toner image formed on the electrophotographic photoreceptor to the recording medium. 【0139】 (Fixing process) The toner image transferred to the recording medium is an unfixed image. In this process, the recording medium on which the toner has been transferred and the unfixed image has been formed is passed between a heated fixing belt or fixing roller and a pressurizing member, thereby fixing the unfixed image to the recording medium. 【0140】 Examples of fixing methods include a belt fixing method or a roller fixing method, which consist of a fixing belt or fixing roller as a fixing rotating body and a pressure roller as a pressing member that is pressed against the fixing belt or fixing roller so that a fixing nip portion is formed. 【0141】 (Cleaning process) In this process, any developer that was not used for image formation or that remained untransferred on the developer holder, such as a photoreceptor or intermediate transfer body, is removed from the developer holder. 【0142】 The cleaning method is not particularly limited, and one example is a method using a blade whose tip is in contact with the object to be cleaned, such as a photoreceptor, and which rubs the surface of the photoreceptor. 【0143】 (Recording medium) There are no particular restrictions on the recording medium. Examples of recording media include ordinary paper ranging from thin to thick, high-quality paper, art paper, or coated printing paper; commercially available Japanese paper and postcard paper; resin films such as polypropylene (PP) film, polyethylene terephthalate (PET) film, and triacetylcellulose (TAC) film; and cloth. Furthermore, there are no particular restrictions on the color of the recording medium, and recording media of various colors can be used. 【0144】 7. Image forming apparatus The image forming apparatus used in the image forming method of this embodiment will now be described. When the image forming method is an electrophotographic method, an image forming apparatus 100, such as the one shown in Figure 2, can be used as the image forming apparatus. Figure 2 is a schematic diagram showing a cross-section of the image forming apparatus used in the image forming method of this embodiment. The image forming apparatus 100 is called a tandem-type color image forming apparatus. The image forming apparatus 100 has four sets of image forming sections (image forming units) 10Y, 10M, 10C, and 10Bk arranged in a vertical column, an intermediate transfer unit 7, a paper feeding means 21, and a fixing means 24. An original image reading device SC is located on the upper part of the main body A of the image forming apparatus 100. 【0145】 The intermediate transfer unit 7 consists of an endless belt-shaped intermediate transfer body 70 that can be rotated by winding around rollers 71, 72, 73, and 74, primary transfer rollers 5Y, 5M, 5C, 5Bk, and cleaning means 6b. 【0146】 Each of the four sets of image forming units 10Y, 10M, 10C, and 10Bk has a drum-shaped photoreceptor 1Y, 1M, 1C, and 1Bk at its center, and surrounding it are charging means 2Y, 2M, 2C, and 2Bk, exposure means 3Y, 3M, 3C, and 3Bk, rotating developing means 4Y, 4M, 4C, and 4Bk, and cleaning means 6Y, 6M, 6C, and 6Bk for cleaning the photoreceptors 1Y, 1M, 1C, and 1Bk. 【0147】 Image forming units 10Y, 10M, 10C, and 10Bk form toner images of yellow, magenta, cyan, and black, respectively. In the image forming method of this embodiment, the charging step, exposure step, and development step are steps for forming a toner image on a photoreceptor. In the image forming apparatus 100, the following is performed using the photoreceptors 1Y, 1M, 10C, and 1Bk and the toner of this embodiment in the image forming units 10Y, 10M, 10C, and 10Bk. It is preferable that the toner of this embodiment is mixed with a carrier and used as the developer of this embodiment. 【0148】 The image forming units 10Y, 10M, 10C, and 10Bk have the same configuration, differing only in the color of the toner image formed on the photoreceptors 1Y, 1M, 1C, and 1Bk, respectively. The image forming unit 10Y will be explained in detail as an example. 【0149】 The image forming unit 10Y arranges a charging means 2Y, an exposure means 3Y, a developing means 4Y, and a cleaning means 6Y around a photoreceptor 1Y, which is an image forming body. The image forming unit 10Y then forms a yellow (Y) toner image on the photoreceptor 1Y. In the image forming apparatus 100, at least the photoreceptor 1Y, the charging means 2Y, the developing means 4Y, and the cleaning means 6Y of the image forming unit 10Y are integrated into one unit. 【0150】 The charging means 2Y is a means of applying a uniform potential to the photoreceptor 1Y. In the image forming apparatus 100, the charging means can be a contact or non-contact roller charging method. Among these, a contact roller charging method is preferred in that the toner effect of this embodiment is more effective. 【0151】 The exposure means 3Y is a means of exposing a photoreceptor 1Y, which has been given a uniform potential by the charging means 2Y, based on an image signal (yellow), to form an electrostatic image corresponding to the yellow image. Examples of exposure means 3Y include those composed of LEDs and imaging elements arranged in an array along the axial direction of the photoreceptor 1Y, and those using a laser optical system. 【0152】 The developing means 4Y consists of, for example, a developing sleeve that incorporates a magnet and holds and rotates a two-component developer, and a voltage application device that applies a DC or AC bias voltage between the photoreceptor 1Y and the developing sleeve. 【0153】 The cleaning means 6Y consists of a cleaning blade and a brush roller located upstream of the cleaning blade. The cleaning blade is positioned so that its tip contacts the surface of the photoreceptor 1Y. The brush roller is in contact with the surface of the photoreceptor 1Y. The cleaning blade has the function of removing residual toner adhering to the photoreceptor 1Y, as well as the function of rubbing the surface of the photoreceptor 1Y. 【0154】 The brush roller has the function of removing residual toner adhering to the photoreceptor 1Y, recovering residual toner removed by the cleaning blade, and rubbing the surface of the photoreceptor 1Y. In other words, the brush roller comes into contact with the surface of the photoreceptor 1Y. At the contact point, it rotates in the same direction as the photoreceptor 1Y, removing residual toner and paper dust from the photoreceptor 1Y, and transporting and recovering residual toner removed by the cleaning blade. 【0155】 In an image forming method using the image forming apparatus 100, the transfer step involves using an intermediate transfer body. Specifically, the toner image formed on the photoreceptor is first transferred onto the intermediate transfer body, and then this toner image is secondarily transferred onto the recording medium. 【0156】 The toner images of each color formed by the image forming units 10Y, 10M, 10C, and 10Bk are sequentially transferred onto the rotating endless belt-shaped intermediate transfer body 70 of the intermediate transfer body unit 7 by primary transfer rollers 5Y, 5M, 5C, and 5Bk, which serve as primary transfer means. A combined color image is then formed. The endless belt-shaped intermediate transfer body 70 is a semiconductive endless belt-shaped second image holder that is wound around a plurality of rollers 71, 72, 73, and 74 and rotatably supported. 【0157】 The color image synthesized on the endless belt-shaped intermediate transfer body 70 is then transferred to the recording medium P. The recording medium P is an image support that carries the fixed final image. Examples of recording medium P include plain paper and transparent sheets. Specifically, the recording medium P housed in the paper feed cassette 20 is fed by the paper feeding means 21. The recording medium P is then transported via a plurality of intermediate rollers 22A, 22B, 22C, 22D and a registration roller 23 to a secondary transfer roller 5b, which serves as a secondary transfer means. The color image is then transferred (secondary transfer) from the endless belt-shaped intermediate transfer body 70 to the recording medium P by the secondary transfer roller 5b. The recording medium P on which the color image has been transferred is then fixed by the fixing means 24 and placed on the paper output tray 26 outside the machine, held between the paper output roller 25. 【0158】 The fixing means 24 may be, for example, a heat roller fixing method comprising a heating roller equipped with a heating source inside and a pressure roller provided in a state of being pressed against the heating roller so as to form a fixing nip portion. 【0159】 On the other hand, after a color image is transferred to the recording medium P by the secondary transfer roller 5b, which acts as a secondary transfer means, the endless belt-shaped intermediate transfer body 70, which has been separated from the recording medium P by curvature, has residual toner removed by the cleaning means 6b. 【0160】 During the image formation process, the primary transfer roller 5Bk is always in contact with the photoreceptor 1Bk. The other primary transfer rollers 5Y, 5M, and 5C are in contact with their respective photoreceptors 1Y, 1M, and 1C only when a color image is being formed. The secondary transfer roller 5b is in contact with the endless belt-shaped intermediate transfer body 70 only when the recording medium P passes over it and secondary transfer is performed. 【0161】 Furthermore, in the image forming apparatus 100, the housing 8, which consists of the image forming sections 10Y, 10M, 10C, and 10Bk and the intermediate transfer unit 7, can be extended from the main body A of the apparatus via support rails 82L and 82R. 【0162】 The image forming apparatus 100 shown in Figure 2 is an image forming apparatus in a color laser printer. Other image forming apparatuses that can be used in the image forming method of this embodiment include monochrome laser printers and copiers. Furthermore, a light source other than a laser may be used as the exposure light source, such as an LED light source. [Examples] 【0163】 The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, in the following examples, unless otherwise specified, the operations are carried out at room temperature (25°C), and % refers to mass%. 【0164】 <Preparation of toner for developing electrostatic images> [Production of inorganic microparticles] (Preparation of silica particles 1) Silica particles 1 were prepared as inorganic fine particles to be used as an external additive. The kinematic viscosity at 25°C was 100 mm². 2A hexane solution was prepared by diluting 10 parts by mass of silicone oil with a concentration of 1 / s with 50 parts by mass of hexane. The silicone oil is a surface modifier. As the silicone oil, "KF 96 100cs (product name)" manufactured by Shin-Etsu Chemical Co., Ltd. was used. 60 parts by mass of the hexane solution was sprayed onto 100 parts by mass of silica particles while stirring the silica particles under a nitrogen atmosphere. As the silica particles, silica particles with a number-average primary particle size of 40 nm, produced by a gas-phase method, were used. The resulting reaction mixture was stirred under a nitrogen atmosphere at 250°C for 60 minutes, dried, cooled, and the silica particles were recovered. In the column for Surface Modification 1 in Table 1, the amount of surface modifier (parts by mass) is the amount (parts by mass) relative to 100 parts by mass of silica particles. 【0165】 The recovered silica particles were placed in hexane and dispersed using an ultrasonic disperser for 10 minutes. Afterward, they were centrifuged, the precipitate was collected, and the mixture was dried under reduced pressure. The kinematic viscosity at 25°C was 10 mm². 2 A hexane solution was prepared by diluting 0.5 parts by mass of silicone oil with a concentration of 0.5 / s with 25 parts by mass of hexane. Shin-Etsu Chemical Co., Ltd.'s "KF 96 10cs (trade name)" was used as the silicone oil. 25.5 parts by mass of the hexane solution was sprayed onto 50 parts by mass of the above-mentioned solids, which had been dried under reduced pressure, while stirring the solids under a nitrogen atmosphere. The reaction mixture was stirred under a nitrogen stream at 300°C for 60 minutes, dried, and cooled to recover the silica particles 1. In Table 1, the amount of surface modifier (parts by mass) in the "Surface Modification 2" column is the amount (parts by mass) relative to 50 parts by mass of silica particles. The particle size of silica particles 1 can be changed by the reaction conditions in the gas phase method, such as flame temperature, hydrogen or oxygen content, residence time in the flame, or length of the aggregation zone. 【0166】 (Preparation of silica particles 2-7, 11-17, 23-29) As inorganic fine particles, silica particles 2-7, 11-17, and 23-29 were prepared. As shown in Table 1, silica particles 2-7, 11-17, and 23-29 were prepared in the same manner as silica particle 1, except that the surface modification conditions were changed. In Tables 1 and 2, "Silica 1-Silica 29" refers to "Silica particle 1-Silica particle 29". 【0167】 (Preparation of silica particles 8) As inorganic nanoparticles, silica particles 8 were prepared. The kinematic viscosity at 25°C was 100 mm². 2 A hexane solution was prepared by diluting 10 parts by mass of silicone oil with a concentration of 1 / s with 50 parts by mass of hexane. The silicone oil is a surface modifier. As the silicone oil, "KF 96 100cs (trade name)" manufactured by Shin-Etsu Chemical Co., Ltd. was used. 60 parts by mass of the hexane solution was sprayed onto 100 parts by mass of silica particles while stirring the silica particles under a nitrogen atmosphere. As the silica particles, silica particles with a number-average primary particle size of 40 nm, produced by a gas-phase method, were used. The resulting reaction mixture was stirred under a nitrogen atmosphere at 250°C for 60 minutes, dried, cooled, and the silica particles were recovered. 【0168】 The kinematic viscosity at 25°C is 200 mm². 2 A hexane solution was prepared by diluting 0.5 parts by mass of silicone oil with a concentration of 0.5 / s with 25 parts by mass of hexane. The silicone oil used was "KF 96 200cs (product name)" manufactured by Shin-Etsu Chemical Co., Ltd. 25.5 parts by mass of the hexane solution was sprayed onto 50 parts by mass of the recovered silica particles under a nitrogen atmosphere while stirring the silica particles. The reaction mixture was stirred under a nitrogen stream at 250°C for 60 minutes, dried, and cooled to recover the silica particles. 【0169】 (Preparation of silica particles 9 and 10) As inorganic fine particles, silica particles 9 and 10 were prepared. Silica particles 9 and 10 were prepared in the same manner as silica particle 8, except that the surface modification conditions were changed as shown in Table 1. 【0170】 (Preparation of silica particles 18-22) As inorganic fine particles, silica particles 18-22 were prepared. Silica particles 18-22 were prepared in the same manner as silica particle 1, except that the particle size of the silica particles was varied as shown in Table 2. The particle size of the silica particles was adjusted by changing the reaction conditions when the silica particles were prepared by the gas phase method. The changed reaction conditions were the flame temperature, the hydrogen or oxygen content, the residence time in the flame, or the length of the aggregation zone. 【0171】 [Table 1] 【0172】 In Table 1, "KF99" represents methylhydrogenpolysiloxane. "X-21-5841" represents silanol-terminated silicone oil, which is dimethylpolysiloxane with silanol-modified ends. "XBE-3083" represents octyltriethoxysilane. "KF-96-10cs" represents polydimethylsiloxane (PDMS) with a kinematic viscosity of 10 mmHg at 25°C. 2 The value is / s. Similarly, "KF-96-50cs", "KF-96-100cs", "KF-96-200cs", "KF-96-300cs", "KF-96-350cs", and "KF-96-500cs" also indicate polydimethylsiloxane (PDMS), and the number immediately preceding "cs" in each case represents the kinematic viscosity (mm²) at 25°C. 2 This indicates / s). 【0173】 [Table 2] 【0174】 In Table II, "PDMS" represents polydimethylsiloxane. "MHSO" represents methylhydrogenpolysiloxane. "SNSO" represents silanol-terminated silicone oil, which is "X-21-5841" listed in Table I. "OTES" represents octyltriethoxysilane, which is "XBE-3083" listed in Table I. The inorganic particulate matter content (parts by mass) in the toner column means the amount of inorganic particulate matter (parts by mass) per 100 parts by mass of toner. In the "Free component content in silica" column in Table II, for Example 25, the free component content in titania is listed. 【0175】 (Production of Titania particle 1) Titania particles 1 were prepared as inorganic nanoparticles. Titania particles 1 were prepared in the same manner as silica particles 2, except that titania particles were used instead of silica particles. The titania particles used were those with a number-average primary particle size of 20 nm, prepared by a gas-phase method. 【0176】 [Preparation of toner matrix particles] [Preparation of Styrene-Acrylic Resin Particle Dispersion] (First stage polymerization) A reaction vessel equipped with a stirrer, temperature sensor, cooling pipe, and nitrogen introduction device was charged with an aqueous surfactant solution prepared by dissolving 4 parts by mass of anionic surfactant in 3040 parts by mass of deionized water. Sodium dodecyl sulfate was used as the anionic surfactant. Furthermore, a polymerization initiator solution prepared by dissolving 10 parts by mass of potassium persulfate (KPS) in 400 parts by mass of deionized water was added, and the liquid temperature was raised to 75°C. 【0177】 Next, a polymerizable monomer solution consisting of 532 parts by mass of styrene, 200 parts by mass of n-butylacrylic acid, 68 parts by mass of methacrylic acid, and 16.4 parts by mass of n-octyl mercaptan was added dropwise over 1 hour. After addition, polymerization (first-stage polymerization) was carried out by heating and stirring at 75°C for 2 hours to prepare a dispersion of styrene-acrylic resin particles. These styrene-acrylic resin particles are sometimes referred to as "StAc resin particles" or "StAc". 【0178】 The weight-average molecular weight (Mw) of the StAc resin particles in the dispersion was 16,500. The weight-average molecular weight (Mw) was determined from the molecular weight distribution measured by gel permeation chromatography (GPC). Specifically, the sample was added to tetrahydrofuran (THF) to a concentration of 1 mg / mL, and dispersed at room temperature using an ultrasonic disperser for 5 minutes to obtain the THF solution of the sample. Subsequently, the THF solution was processed through a membrane filter with a pore size of 0.2 μm to prepare the sample solution. A GPC instrument HLC-8120GPC (Tosoh Corporation) was used for the GPC measurement. A triple-tube "TSKguardcolumn+TSKgelSuperHZ-m" column (Tosoh Corporation) was used as the column. During the measurement, the column temperature was maintained at 40°C, and tetrahydrofuran, the carrier solvent, was flowed at a flow rate of 0.2 mL / min. 10 μL of the prepared sample solution was injected into the GPC instrument along with a carrier solvent. The sample was detected using a refractive index detector (RI detector), and the molecular weight distribution of the sample was calculated using a calibration curve. The calibration curve used was one measured using monodisperse polystyrene standard particles. The calibration curve was calculated for molecular weights of 6 × 10⁶. 2 , 2.1 × 10 3 , 4×10 3 , 1.75 × 10 4 , 5.1×10 4 , 1.1 × 10 5 , 3.9×10 5 , 8.6×10 5 , 2×10 6 , 4.48×10 6 This was created by measuring 10 polystyrene standard particles (manufactured by Pressure Chemical). 【0179】 (Second stage polymerization) A polymerizable monomer solution consisting of 101.1 parts by mass of styrene, 62.2 parts by mass of n-butylacrylic acid, 12.3 parts by mass of methacrylic acid, and 1.75 parts by mass of n-octyl mercaptan was charged into a flask equipped with a stirring device. Furthermore, 93.8 parts by mass of paraffin wax HNP-57 (manufactured by Nippon Wax Co., Ltd.) was added as a release agent, and the monomer solution was prepared by heating the internal temperature to 90°C and dissolving the mixture. 【0180】 In a separate container, an aqueous surfactant solution was prepared by dissolving 3 parts by mass of the anionic surfactant used in the first polymerization in 1560 parts by mass of deionized water. The surfactant solution was then heated to 98°C. To this surfactant solution, 32.8 parts by mass (in terms of solid content) of a dispersion of styrene-acrylic resin particles obtained in the first polymerization was added, followed by a monomer solution containing paraffin wax. The mixture was then mixed and dispersed over 8 hours using a mechanical disperser with a circulation path, Creamix (manufactured by M-Technique). This prepared a dispersion of emulsion particles (oil droplets) with a particle size of 340 nm. 【0181】 A polymerization initiator solution, prepared by dissolving 6 parts by mass of potassium persulfate in 200 parts by mass of deionized water, was added to this dispersion. Polymerization (second-stage polymerization) was carried out by heating and stirring this system at 98°C for 12 hours to prepare a dispersion of styrene-acrylic resin particles. The weight-average molecular weight (Mw) of the styrene-acrylic resin particles in the dispersion was 23,000. 【0182】 (Third stage polymerization) To the dispersion of styrene-acrylic resin particles obtained in the second stage of polymerization, a polymerization initiator solution was added, prepared by dissolving 5.45 parts by mass of potassium persulfate in 220 parts by mass of deionized water. To this dispersion, a polymerizable monomer solution consisting of 293.8 parts by mass of styrene, 154.1 parts by mass of n-butylacrylic acid, and 7.08 parts by mass of n-octyl mercaptan was added dropwise over 1 hour at a temperature of 80°C. After the addition was complete, polymerization (third stage polymerization) was carried out by heating and stirring for 2 hours. After polymerization, the mixture was cooled to 28°C to obtain the desired dispersion of styrene-acrylic resin particles. The weight-average molecular weight (Mw) of the styrene-acrylic resin particles in the dispersion was 26800. 【0183】 [Preparation of amorphous polyester particle dispersion] A reaction vessel equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectification column was charged with polyhydric carboxylic acid monomers and polyhydric alcohol monomers. As polyhydric carboxylic acid monomers, 139.5 parts by mass of terephthalic acid and 15.5 parts by mass of isophthalic acid were charged. As polyhydric alcohol monomers, 290.4 parts by mass of 2,2-bis(4-hydroxyphenyl)propanepropylene oxide 2 molar adduct (molecular weight = 460) and 60.2 parts by mass of 2,2-bis(4-hydroxyphenyl)propaneethylene oxide 2 molar adduct (molecular weight = 404) were charged. 【0184】 The temperature of the reaction system in the reaction vessel was raised to 190°C over 1 hour. After confirming that the reaction system was uniformly stirred, 3.21 parts by mass of tin octoate were added as a catalyst. While distilling off the generated water, the temperature of the reaction system was raised from the same temperature to 240°C over 6 hours. The dehydration condensation reaction was then carried out continuously for 6 hours at 240°C to obtain an amorphous polyester resin. The obtained amorphous polyester resin had a peak molecular weight (Mp) of 12,000 and a weight-average molecular weight (Mw) of 15,000. 【0185】 (Preparation of amorphous polyester resin particle dispersion) The following components were placed in a separable flask, thoroughly mixed and dissolved, and then deionized water was added dropwise at a rate of 8 g / min using a liquid delivery pump while heating and stirring at 40°C. Amorphous polyester resin 200.00 parts by mass Methyl ethyl ketone 100.00 parts by mass Isopropyl alcohol 35.00 parts by mass 7.00 parts by mass of 10% by mass aqueous ammonia solution 【0186】 After the mixture became uniformly cloudy, the delivery rate was increased to 15 g / min to induce phase inversion, and the dropping was stopped when the volume reached 580 parts by mass. Subsequently, the solvent was removed under reduced pressure to obtain an amorphous polyester resin particle dispersion. The volume-average particle size of the obtained amorphous polyester resin particles was measured using a particle size analyzer "Nanotrack Wave" (Microtrac-Bell), and it was found to be 216 nm. The solid content concentration in the amorphous polyester resin particle dispersion was 20% by mass. 【0187】 [Coloring agent particle dispersion] 90 parts by mass of sodium dodecyl sulfate were dissolved by stirring in 1600 parts by mass of deionized water. While stirring this solution, 420 parts by mass of carbon black legal 330R (Cabot Corporation) were gradually added. Next, a dispersion of colorant particles was prepared by dispersing the mixture using a stirring device, Creamix (product name) (M-Technique Corporation). The particle size of the colorant particles in the dispersion was measured using a particle size distribution analyzer, Nanotrack Wave (product name) (Microtrac Bell Corporation), and was found to be 117 nm. 【0188】 [Preparation of toner matrix particles 1] 300 parts by mass of the styrene-acrylic resin particle dispersion (based on solid content) and 2000 parts by mass of deionized water were added to a reaction vessel equipped with a stirrer, temperature sensor, and cooling tube. Then, a 5 mol / liter sodium hydroxide aqueous solution was added to the reaction vessel to adjust the pH to 10. Next, 40 parts by mass of the colorant dispersion (based on solid content) was added. Subsequently, an aqueous solution of 60 parts by mass of magnesium chloride dissolved in 60 parts by mass of deionized water was added over 10 minutes at 30°C under stirring. After standing for 3 minutes, the temperature was increased, and the system was heated to 80°C over 60 minutes, maintaining the temperature at 80°C while continuing the particle growth reaction. Under these conditions, the particle size of the associated particles was measured using a "Multisizer 3" (product name) (manufactured by Beckman Coulter), and the median diameter (D) on a volume basis was measured. 50 When the particle size reached 5.6 μm, 30 parts by mass of the dispersion of amorphous polyester resin particles was added over 30 minutes based on solid content. When the supernatant of the reaction solution became clear, an aqueous solution of 190 parts by mass of sodium chloride dissolved in 760 parts by mass of ion-exchanged water was added to stop particle growth. The temperature was then increased, and the mixture was heated and stirred at 90°C to promote particle fusion. When the average circularity of the particles reached 0.950, it was cooled to 30°C to prepare the toner matrix particle dispersion. The average circularity of the particles was measured using the "FPIA-2100" (product name) (manufactured by Sysmex). The measurement of the average circularity of the particles using "FPIA-2100" was performed with an HPF detection count of 4000. 【0189】 The resulting dispersion of toner matrix particles was subjected to solid-liquid separation using a centrifuge to form a wet cake of toner matrix particles. The resulting wet cake was then washed with deionized water at 35°C using the same centrifuge until the electrical conductivity of the filtrate was 5 μS / cm. Subsequently, the wet cake was transferred to a "Flash Jet Dryer" (product name) (manufactured by Seishin Corporation) and dried until the moisture content was 0.5% by mass to produce toner matrix particles 1. The resulting toner matrix particles 1 had a median diameter (D) based on volume. 50 The diameter was 5.9 μm, and the average circularity was 0.955. 【0190】 [Preparation of toner matrix particles 2] (Preparation of crystalline polyester resin particle dispersion) A mixture was prepared by adding the following components to a three-necked flask, and then the pressure inside the container was reduced by a vacuum procedure. 1,9-nonanediol 300.00 parts by mass Dodecanedioic acid 250.00 parts by mass Titanium butoxide (Ti(OBu)4) 3.50 parts by mass 【0191】 Furthermore, nitrogen gas was introduced into the three-necked flask to create an inert atmosphere, and the mixture was refluxed at 180°C for 6 hours while being mechanically stirred. After that, unreacted monomer components were removed by vacuum distillation, and the temperature was gradually increased to 220°C, with stirring for 12 hours. Once the mixture became viscous, it was cooled to obtain a dispersion of crystalline polyester resin particles. 【0192】 The weight-average molecular weight (Mw) of the crystalline polyester resin contained in the obtained dispersion of crystalline polyester resin particles was 19500. The melting point of the crystalline polyester resin was 75°C. The weight-average molecular weight (Mw) and melting point were measured using the following method. 【0193】 (Method for measuring weight-average molecular weight) The weight-average molecular weight was calculated using a calibration curve of monodisperse polystyrene standard particles by gel permeation chromatography (GPC) under the following conditions. The calibration curve was calculated for molecular weights of 6.00 × 10⁻⁶. 2 , 2.10 × 10 3 , 4.00×10 3 , 1.75 × 10 4 , 5.10×10 4 , 1.10 × 10 5 , 3.90×10 5 , 8.60×10 5 , 2.00×10 6 , 4.48×10 6Ten polystyrene standard particles (manufactured by Pressure Chemical) were measured and prepared. 【0194】 The sample was prepared by adding it to tetrahydrofuran (THF) to a concentration of 1 mg / mL, dispersing it using an ultrasonic disperser at room temperature for 5 minutes, and then processing it through a membrane filter with a pore size of 0.2 μm. 【0195】 Equipment: GPC system "HLC-8220GPC" (manufactured by Tosoh Corporation) Column: "TSKguardcolumn + TSKgel(registered trademark) SuperHZM-M3" (manufactured by Tosoh Corporation) Carrier solvent: Tetrahydrofuran (THF) Detector: Differential refractive index detector (RI detector) Column temperature: 40℃ Flow rate: 0.2mL / min Sample: 10 μL 【0196】 (Method for measuring melting point) The melting point was determined using a differential scanning calorimetry system (Diamond DSC) manufactured by PerkinElmer. A 3.0 mg sample was sealed in an aluminum pan and set in the holder, with an empty aluminum pan set as a reference. The measurement conditions (heating and cooling conditions) were as follows: a first heating process where the temperature was raised from 0°C to 200°C at a heating rate of 10°C / min, a cooling process where the temperature was cooled from 200°C to 0°C at a cooling rate of 10°C / min, and a second heating process where the temperature was raised from 0°C to 200°C at a heating rate of 10°C / min. A DSC curve was obtained under these measurement conditions. Based on this DSC curve, the endothermic peak top temperature originating from the sample during the first heating process was defined as the melting point. 【0197】 (Preparation of amorphous polyester resin particle dispersion (2)) (Preparation of amorphous polyester resin (2)) The monomers and catalyst listed below were placed in a heated and dried three-necked flask. The air inside the flask was then reduced by vacuum, and an inert atmosphere was created using nitrogen gas. The mixture was then refluxed at 180°C for 5 hours with mechanical stirring. Bisphenol A propylene oxide 2100.00 parts by mass Bisphenol A ethylene oxide 1600.00 parts by mass 1,3,5-Benzenetricarboxylic acid 55.00 parts by mass 1,2,4-Benzenetricarboxylic acid 620.00 parts by mass Terephthalic acid 730.00 parts by mass Fumaric acid 400.00 parts by mass Dibutyltin oxide 25.00 parts by mass 【0198】 Subsequently, the water generated in the reaction system was removed by vacuum distillation while the temperature was gradually increased to 240°C. The dehydration condensation reaction was then continued at 240°C for 3 hours. After the mixture became viscous, the molecular weight was confirmed by gel permeation chromatography (GPC), and the reaction was stopped. When the mass-average molecular weight reached 36,000, vacuum distillation was stopped to obtain amorphous polyester resin (2). 【0199】 (Preparation of amorphous polyester resin particle dispersion (2)) The following components were placed in a separable flask, thoroughly mixed and dissolved, and then deionized water was added dropwise at a rate of 8 g / min using a liquid delivery pump while heating and stirring at 40°C. Amorphous polyester resin (2) 200.00 parts by mass Methyl ethyl ketone 100.00 parts by mass Isopropyl alcohol 35.00 parts by mass 7.00 parts by mass of 10% by mass aqueous ammonia solution 【0200】 After the mixture became uniformly cloudy, the liquid delivery rate was increased to 15 g / min to induce phase inversion, and the dropping was stopped when the volume reached 580 parts by mass. Subsequently, the solvent was removed under reduced pressure to obtain amorphous polyester resin particle dispersion (2). The volume-average particle size of the obtained amorphous polyester resin particles was measured using a particle size analyzer "Nanotrack Wave" (manufactured by Microtrac-Bell) and found to be 164 nm, and the solid content concentration in amorphous polyester resin particle dispersion (2) was 35% by mass. 【0201】 (Preparation of a dispersion of coloring agent particles) The following ingredients were mixed, stirred, and dissolved. Sodium dodecyl sulfate 90.00 parts by mass Ion-exchanged water 1600.00 parts by mass 【0202】 The following components were gradually added to the resulting solution while stirring. Carbon Black "REGAL(registered trademark) 330R" (manufactured by Cabot) 420.00 parts by mass 【0203】 Next, a dispersion of colorant particles was prepared by dispersing them using a stirring device, Creamix (manufactured by M-Technique). The volume-average particle size of the obtained colorant particles was measured using a particle size analyzer, Nanotrack Wave (manufactured by Microtrac-Bell), and was found to be 117 nm. 【0204】 (Preparation of mold release agent particle dispersion) The following components were mixed, and the release agent was dissolved in a pressure-discharge homogenizer (Gorin homogenizer, manufactured by Gorin Corporation) at an internal liquid temperature of 120°C. Subsequently, the mixture was dispersed at a dispersion pressure of 5 MPa for 120 minutes, followed by a dispersion at 40 MPa for 360 minutes, and then cooled to obtain the dispersion. Paraffin wax "HNP0190" (manufactured by Nippon Seiro Co., Ltd., melting point: 85℃) 270.00 parts by mass Anionic surfactant "Neogen® RK" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 60% active ingredient, 3% release agent) 13.50 parts by mass Ion-exchanged water 21.60 parts by mass 【0205】 Deionized water was added to adjust the solid content to 20% by mass, and a release agent particle dispersion was obtained. The volume-average particle diameter of the obtained release agent particles was measured using a particle size analyzer "Nanotrack Wave" (manufactured by Microtrac-Bell) and was found to be 215 nm. 【0206】 (Agglomeration / fusion process and maturation process) The following components were placed in a polymerization vessel equipped with a pH meter, stirring blades, and a thermometer, and the surfactant was mixed with the amorphous polyester resin particle dispersion (2) and the crystalline polyester resin particle dispersion while stirring at 140 rpm for 15 minutes. Amorphous polyester resin particle dispersion (2) 100.00 parts by mass 12.80 parts by mass of crystalline polyester resin particle dispersion. Anionic surfactant ("DOWFAX® 2A1" (manufactured by Dow Toray Corporation) 20% by mass aqueous solution) 4.10 parts by mass Ion-exchanged water 250.00 parts by mass 【0207】 Next, the following components were added and mixed, and then a 0.3 M nitric acid solution was added to adjust the pH to 4.8. Coloring agent particle dispersion: 15.00 parts by mass Release agent particle dispersion 12.00 parts by mass 【0208】 Next, the following components were added dropwise as a flocculant using a homogenizer "ULTRA-TURRAX® series" (manufactured by IKA Corporation) at a rotation speed of 4000 rpm while applying shear force. During the addition of the flocculant (listed components), the viscosity of the raw material mixture increased rapidly. Therefore, the adding speed was slowed down when the viscosity increased to prevent the flocculant from accumulating in one place. After adding the flocculant, the rotation speed was increased to 5000 rpm and the mixture was stirred for 5 minutes to thoroughly mix the flocculant and the raw material mixture. 22.00 parts by mass of 10% by mass nitric acid aqueous solution of aluminum sulfate 【0209】 The above raw material mixture was then heated to 30°C using a mantle heater while being stirred at a rotation speed of 400-600 rpm. After stirring for 10 minutes, the formation of stable primary particles was confirmed using a precision particle size distribution analyzer "Coulter Multisizer 3" (manufactured by Beckman Coulter, aperture diameter 100 μm). Then, in order to grow core particles, the temperature was increased to 46°C at a heating rate of 0.1°C / min. The growth of the core particles was monitored continuously using a Coulter counter, and the aggregation temperature and the rotation speed of the stirring blades were adjusted as appropriate based on the aggregation rate. 【0210】 On the other hand, for the shell layer, the following components were mixed to prepare a dispersion of binder resin particles for the shell layer, and the pH was set to 3.8. Amorphous polyester resin particle dispersion (2) 55.00 parts by mass Ion-exchanged water 22.00 parts by mass Anionic surfactant ("DOWFAX® 2A1" (manufactured by Dow Toray Corporation) 20% by mass aqueous solution) 0.80 parts by mass 【0211】 In the above aggregation process, when the core particles grew to a particle size of 5.2 μm, a pre-prepared dispersion of binder resin particles for the shell layer was added and held for 10 minutes while stirring. Subsequently, in order to stop the growth of the coated (shell-forming) core particles, the following components were added, and then a 1 M sodium hydroxide aqueous solution was added to adjust the pH of the raw material mixture to 7.5. EDTA (ethylenediaminetetraacetic acid) 20% by mass solution 0.80 parts by mass 【0212】 Then, in order to fuse the coated core particles, the temperature was raised to 85°C at a rate of 1°C / min while adjusting the pH to 7.5. Even after reaching 85°C, the pH was adjusted to 7.5 to further promote fusion. 【0213】 (cooling process) Subsequently, using the flow-type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation), when the average circularity reached 0.965, the mixture was rapidly cooled at a cooling rate of 10°C / min to obtain toner matrix particle dispersion 2. 【0214】 (Filtration, washing, and drying processes) The obtained toner matrix particle dispersion 2 was filtered and thoroughly washed with deionized water. It was then dried at 40°C to obtain toner matrix particles 2. The obtained toner matrix particles 2 had a volume-based median diameter of 6.1 μm and an average circularity of 0.954. Toner matrix particles 2 are the toner matrix particles used in the toner in Example 23. 【0215】 [Creating Toner 1] To the "toner matrix particles 1" prepared as described above, inorganic fine particles, silica particles 1, were added as an external additive. The silica particle content was 1.1 parts by mass per 100 parts by mass of toner matrix particles 1. The mixture of toner matrix particles 1 and silica particles 1 was then charged into a Henschel mixer "Model: FM20C / I" (manufactured by Nippon Coke Industries Co., Ltd.). The rotation speed was set to 50 m / s at the tip of the blades, and the mixture was stirred for 20 minutes to produce "toner 1" containing toner matrix particles 1 and silica particles 1. The temperature of the mixture during stirring in the Henschel mixer was set to 40°C ± 1°C. When the temperature reached 41°C, cooling water was flowed into the outer bath of the Henschel mixer at a flow rate of 5 L / min. When the temperature reached 39°C, the flow rate of cooling water was reduced to 1 L / min to control the temperature inside the Henschel mixer. 【0216】 (Free portion) The free components were separated from the toner, and the weight-average molecular weight, number-average molecular weight, and content of the free components were determined. 【0217】 (Separation of free components) The free components were separated from the toner using the following method. First, 3 g of toner was placed in a 50 mL screw-cap vial, wetted with 40 g of methanol, and stirred. Then, it was transferred to a 60 mL disposable cup, and an ultrasonic homogenizer "US-1200T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.) was used, with the tip of the ultrasonic transducer (φ36) immersed in the liquid to about 3 cm. After that, the ultrasonic energy was adjusted to 100 W, and ultrasound was applied for 1 minute to obtain a dispersion. The obtained dispersion was transferred to a 15 mL test tube, and after standing overnight, the supernatant was collected. The above procedure, from 3 g of toner to collection of the supernatant, was repeated 50 times. The collected supernatant was concentrated to dryness. The solid obtained by concentration to dryness was refluxed with methyl ethyl ketone, and the methyl ethyl ketone-soluble components were removed to obtain a solid sample. Specifically, after the above reflux, the solid components were separated by ultra-cooled centrifugation to obtain a solid sample. Ultra-cooled centrifugation was performed at a temperature of 10°C and a rotation speed of 50,000 rpm. A himac CS150NX (trade name) (manufactured by Eppendorf Himac Technologies) was used as the measuring device for ultra-cooled centrifugation. The obtained solid sample was weighed in a 50 mL glass centrifuge tube. Then, 20 mL of chloroform was added to the centrifuge tube, and ultrasonic waves were applied for 10 minutes using the ultrasonic homogenizer described above. After that, centrifugation was performed at 3500 rpm for 10 minutes. The clear supernatant obtained by centrifugation was transferred to a 100 mL round-bottom flask and dried under reduced pressure. The solid obtained by drying under reduced pressure was subjected to the same procedure again, starting from "weighing in a 50 mL glass centrifuge tube" to obtain the free component. 【0218】 (Weight-average molecular weight of free components) The weight-average molecular weight of the free component was calculated using GPC measurements under the following conditions and calibration curves for standard polystyrene and n-hexylbenzene. To perform GPC measurement on the free component, 2 mg of the free component was weighed, 2 mL of toluene was added dropwise, and the sample solution was filtered through a pore-size 0.2 μm membrane filter to prepare the GPC measurement sample solution. The conditions for performing GPC measurement on the free component were as follows. 【0219】 GPC measurement device: HLC-8420GPC (manufactured by Tosoh Corporation) Column: Shodex K-806M (manufactured by Resonaq) Column temperature: 45℃ Carrier solvent: Toluene for HPLC Carrier solvent rate: 1.0 mL / min Sample solution: 200 μL Detector: Differential refractive index detector (RI detector) 【0220】 The calibration curves are for molecular weights of 5.80 × 10⁻⁶ each. 2 , 1.25 × 10 3 , 4.91×10 3 , 9.82×10 3 , 2.29 × 10 4 , 6.76×10 4 , 2.17 × 10 5 , 5.37×10 5 , 9.20×10 5 , 3.15×10 6 , 6.57×10 6 The samples were prepared by measuring 11 standard polystyrene (manufactured by Agilent) and n-hexylbenzene (manufactured by Tokyo Chemical Industry Co., Ltd.). 【0221】 (Number-average molecular weight of free components) The number-average molecular weight of the free components was obtained by measuring it in the same manner as the weight-average molecular weight measurement method described above, but calculating the number-average instead of the weight-average. 【0222】 (Content of free components in toner) The content of the free component in the toner is the amount of the free component extracted from the toner with respect to the "total amount of the toner", and is expressed as the mass (mg) of the free component in 1 kg of the toner. The content of the free component in the toner was determined using the free component obtained by the method of "separation of the free component" described above. Since the free component obtained by the method of "separation of the free component" may contain impurities, the accurate content of the free component was determined by performing GPC measurement. Then, the value of the mass obtained by performing GPC measurement on the obtained free component with respect to the mass of the toner used in the method of "separation of the free component" was expressed as the mass (mg) of the free component in 1 kg of the toner, and thus the content (mg / kg) of the free component in the toner was obtained. The content of the free component was obtained by performing GPC measurement under the following conditions using polydimethylsiloxane as a standard. Specifically, a polydimethylsiloxane solution with a known concentration was subjected to GPC measurement under the following conditions, and it was determined by the absolute calibration curve method using the polydimethylsiloxane as a standard. Commercially available polydimethylsiloxane (product number 181846-25G manufactured by Sigma-Aldrich) was used. 【0223】 GPC measuring device: HLC-8420GPC (manufactured by Tosoh Corporation) Column: Shodex K-806M (manufactured by Resonac Corporation) Column temperature: 45 °C Carrier solvent: Toluene for HPLC Carrier solvent flow rate: 1.0 mL / min Sample solution: 200 μL Detector: Differential refractive index detector (RI detector) 【0224】 (Free component content in silica) The "free content in silica," which is the free content in inorganic fine particles, was measured using the same method as the "free content in toner" measurement method described above. The method for extracting free content from silica particles or titania particles is as follows: 0.8 g of the prepared silica particles or titania particles were weighed into a 50 mL glass centrifuge tube. Then, 20 mL of chloroform was added to the centrifuge tube, and ultrasonic waves were applied for 10 minutes using the ultrasonic homogenizer described above. After that, centrifugation was performed at 3500 rpm for 10 minutes. The clear supernatant obtained by centrifugation was transferred to a 100 mL round-bottom flask and dried under reduced pressure. The solid content obtained by drying under reduced pressure was repeated from the "weighing in a 50 mL glass centrifuge tube" step described above to obtain the free content. The exact amount of free content was determined by GPC measurement of the obtained free content, and the exact amount of free content relative to the amount of silica particles used to obtain the free content was expressed as the mass of free content per 1 kg of silica (mg), thereby determining the free content in silica (mg / kg). 【0225】 [Career Development] (Preparation of carrier core material particle 1) The raw materials were weighed to obtain MnO:35mol%, MgO:14.5mol%, Fe2O3:50mol%, and SrO:0.5mol%, mixed with water, and then ground in a wet media mill for 5 hours to obtain a slurry. The obtained slurry was dried in a spray dryer to obtain spherical particles. After classifying these particles to adjust the particle size, they were heated at 950°C for 2 hours for calcination. After grinding in a wet ball mill for 1 hour using stainless steel beads with a diameter of 0.3 cm, they were further ground for 4 hours using zirconia beads with a diameter of 0.5 cm. 0.8 parts by mass of PVA (polyvinyl alcohol) was added as a binder per 100 parts by mass of solids, then granulated and dried in a spray dryer, and then calcined in an electric furnace at a temperature of 1350°C for 5 hours. After that, it was crushed, further classified to adjust the particle size, and then low-magnetic-force materials were separated by magnetic separation to obtain carrier core material particles 1. The particle size of carrier core material particle 1 was 35 μm. 【0226】 (Preparation of covering material 1) Cyclohexyl methacrylate and methyl methacrylate were added to a 0.3% by mass aqueous solution of sodium benzenesulfonate. The mass ratio of cyclohexyl methacrylate to methyl methacrylate was set to 5:5. This 5:5 ratio is the copolymerization ratio. Then, potassium persulfate equivalent to 0.5 parts by mass (when the total amount of monomers is 100 parts by mass) was added to carry out emulsion polymerization and obtain a reaction solution. The obtained reaction solution was then dried by spray drying to produce "Coating Material 1". The weight-average molecular weight of the obtained Coating Material 1 was 500,000. The coating material is a resin for coating core materials. 【0227】 (Creation of Carrier 1) 100 parts by mass of the "Carrier Core Particle 1" as core material particles and 4.5 parts by mass of the "Coating Material 1" as core material coating resin were placed into a high-speed stirring mixer equipped with horizontal stirring blades. The mixture was then stirred at 22°C for 15 minutes under conditions where the peripheral speed of the horizontal rotor blades was 8 m / s. Subsequently, the mixture was stirred at 120°C for 50 minutes to coat the surface of the core material particles with the coating material by the action of mechanical impact force (mechanochemical method), thereby producing "Carrier 1". 【0228】 (Preparation of covering material 2) Styrene and methyl methacrylate were added to an aqueous solution of 0.3% by mass of sodium benzenesulfonate. The mass ratio of styrene to methyl methacrylate was set to 5:5. This 5:5 ratio is the copolymerization ratio. Then, potassium persulfate equivalent to 0.5 parts by mass (when the total amount of monomers is 100 parts by mass) was added to carry out emulsion polymerization and obtain a reaction solution. The obtained reaction solution was then dried by spray drying to prepare "Coating Material 2". The weight-average molecular weight of the obtained Coating Material 2 was 450,000. 【0229】 (Creating Carrier 2) 100 parts by mass of the "Carrier Core Particle 1" as core material particles and 4.5 parts by mass of the "Coating Material 2" as core material coating resin were placed into a high-speed stirring mixer equipped with horizontal stirring blades. The mixture was then stirred at 22°C for 15 minutes under conditions where the peripheral speed of the horizontal rotor blades was 8 m / s. Subsequently, the mixture was stirred at 120°C for 50 minutes to coat the surface of the core material particles with the coating material by the action of mechanical impact force (mechanochemical method), thereby producing "Carrier 2". 【0230】 (Preparation of developer) The toner and carrier prepared as described above were mixed to a toner concentration of 6% by mass to prepare a developer (Example 1). A V-type mixer was used for mixing for 30 minutes. Developers were prepared in the same manner as in Example 1, except that the conditions for the type of external additive, the type and amount of surface modification, the type of toner matrix particles and inorganic fine particle content, the type of carrier, and the free components were changed as shown in Table II (Examples 2-32, Comparative Examples 1-4). The obtained developers were evaluated as follows. 【0231】 <Evaluation Method> We evaluated the development leak and density fluctuations after durability testing using a commercially available multifunction printer, the "bizhub Pro C14000" (product name) manufactured by Konica Minolta. 【0232】 [Development leak] In a normal temperature and humidity (20°C, 50%RH) printing environment, after printing 250,000 images of text with a print coverage of 5%, the amount of adhesive residue was 4.0 g / m². 2 The development bias was set accordingly. Then, a solid image was output to check for any obvious leaks. The development bias was increased in 50V increments towards the negative voltage, and the presence or absence of leaks was checked again using solid images. The voltage ΔV, which is the difference between the lowest development bias at which a leak occurred and the initial development bias, was compared. A ΔV of 200V or higher was considered acceptable. 【0233】 (Evaluation Criteria) A: ΔV is 400V or more B: ΔV is 300 V or more and less than 400 V C: ΔV is 200 V or more and less than 300 V D: ΔV is less than 200 V 【0234】 [Concentration Variation] In a printing environment of normal temperature and humidity (20°C, 50% RH), after printing 1000 character images with a printing rate of 50%, the image density difference between the first and 1000th images was evaluated. The evaluation was performed for each solid image of cyan single color (C) and green (G). The image density of the output image was measured under the following conditions using "Spectrolina / Scan Bundle (product name) (manufactured by Gretag Macbeth)". The image density difference was calculated from the obtained image density. Regarding the image density difference, a value of 0.20 or less was considered qualified. 【0235】 (Measurement Conditions) Light source: D50 light source Observation field of view: 2° Density: ANSI T White reference: Abs Filter: UV Cut Measurement mode: Reflectance Language: Japanese For each of cyan single color (C) and green (G), the difference in solid image density ID was calculated. 【0236】 (Evaluation Criteria) A: Image density difference is 0.00 - 0.04 B: Image density difference is 0.05 - 0.10 C: Image density difference is 0.11 - 0.20 D: Image density difference is 0.21 or more 【0237】 The evaluation results are shown in Table III. 【0238】 【Table 3】 【0239】 In Table III, if the measured values ​​for the concentration fluctuations of C and G result in different evaluation results, the result is considered to be somewhere between the two evaluation results. For example, in Example 12, C received a B rating and G received a C rating, so the evaluation result is "BC" to mean somewhere between these two. 【0240】 Table III shows that in the example, the weight-average molecular weight of the free components is between 1000 and 20000, and the free component content is between 2 mg / kg and 700 mg / kg, thus suppressing development leak and minimizing concentration fluctuations. In comparative example 1, the weight-average molecular weight of the free components is too high, resulting in large concentration fluctuations. Comparative example 1 also exhibits large development leaks. In comparative example 2, the weight-average molecular weight of the free components is too low, resulting in large development leaks. Comparative example 2 also exhibits large concentration fluctuations. Comparative Example 3 has a large amount of developer leakage because the free matter content (mg / kg) in the toner is too low. Comparative Example 3 also has large density fluctuations. Comparative Example 4 has large density fluctuations because the free matter content (mg / kg) in the toner is too high. [Explanation of Symbols] 【0241】 100 Image forming apparatus 1Y, 1M, 1C, 1Bk photoconductor 2Y, 2M, 2C, 2Bk Charging means 3Y, 3M, 3C, 3Bk exposure method 4Y, 4M, 4C, 4Bk developing means 5Y, 5M, 5C, 5Bk Primary Transfer Rollers 5b Secondary transfer roller 6Y, 6M, 6C, 6Bk, 6b Cleaning methods 7. Intermediate Transfer Unit 8 cabinets 10Y, 10M, 10C, 10Bk Image Forming Unit 20 Paper feed cassettes 21 Paper feeding means 22A, 22B, 22C, 22D Intermediate Rollers 23 Resist Roller 24 Fixing means 25 Paper output roller 26 Paper output tray 70 Endless belt-shaped intermediate transfer body 71, 72, 73, 74 Rollers 82L, 82R support rails SC Document Image Reader P recording medium

Claims

[Claim 1] A toner for electrostatic image development having toner matrix particles and an external additive, The external additive comprises at least inorganic fine particles, The inorganic fine particles have a surface modifier on their surface, It has free components, The weight-average molecular weight of the free component is 1,000 or more and 20,000 or less. The content of the free component is 2 mg / kg or more and 700 mg / kg or less. A toner for developing electrostatic images, characterized in that the free component is a chloroform extract from a methyl ethyl ketone insoluble substance extracted from the electrostatic image developing toner using methanol. [Claim 2] The electrostatic image developing toner according to claim 1, characterized in that when the weight-average molecular weight of the free components is Mw and the number-average molecular weight of the free components is Mn, the value of Mw / Mn is 1 or more and 3 or less. [Claim 3] The toner for developing electrostatic images according to claim 1, characterized in that the weight-average molecular weight of the free components is 1,000 or more and 10,000 or less. [Claim 4] The electrostatic image developing toner according to claim 1, characterized in that the content of the free components is 2 mg / kg or more and 500 mg / kg or less. [Claim 5] The electrostatic image developing toner according to claim 1, characterized in that the surface modifier is a silicone oil. [Claim 6] The electrostatic image developing toner according to claim 1, characterized in that the inorganic fine particles are silica particles. [Claim 7] A developer which is a mixture of electrostatic image developing toner and carrier according to any one of claims 1 to 6. [Claim 8] An image forming method comprising a development step of developing using an electrostatic image developing toner according to any one of claims 1 to 6.

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