TONER

Abstract

A toner comprises toner particles, each containing a binder resin and a release agent, as well as composite particles, each present on one surface of each toner particle. The release agent has a penetration of 4 or less at 25°C. The composite particles include fine particles A, each containing an organosilicon compound with a siloxane linkage, the organosilicon compound serving as a binder component, and fine particles B, which are composed of inorganic fine particles. Each fine particle B is partially embedded on the surface of each fine particle A. In the fine particles A, the proportions of dibis tetrafunctional silicon atoms meet specific requirements. The fine particles B have a number-averaged primary particle diameter of 0.01 µm or more and 0.06 µm or less.In the composite particles, the average embedding ratios of fine particles B to fine particles A are 30% or more and 90% or less.

Description

BACKGROUNDField of InterestThe present disclosure relates to a toner used in an electrophotographic system, an electrostatic recording system, an electrostatic printing system, and a toner jet system.Description of Related ArtIn recent years, where full-color electrophotographic copiers are widely used, the demand for toners for electrophotography has increased to meet the increasing demands for higher printing speeds in the print-on-demand (POD) area and to achieve a longer life.Heretofore, spherical silica, etc. have been frequently used as external additives for toners. It is also known that the use of irregularly shaped external additives improves cleaning performance and prevents deterioration of the durability of photoconductors.For example, Japanese Patent No. 5982003 discloses an example in which fine particles prepared by adding silica to a vinyl monomer and combining them together are added to toner base particles to improve the flowability of the toner.In Examples of Japanese Patent No. 5982003, there is no description of an example in which a toner containing the fine particles was subjected to an image forming test with a copying machine. However, in the case of a toner to which the fine particles, which are a composite of silica added to a vinyl monomer, are externally added as described in Japanese Patent Publication No. 5982003, the fine particles may be separated from the medium due to the load of a transport roller on the medium in the copying machine as the speed of the copying machine increases. The toner may be transferred from the medium to the conveying roller, and then the transferred toner may cause contamination of an end portion (hereinafter also referred to as "end portion contamination") of the medium conveyed by the copying machine.SHORT DISPLAYThe present disclosure provides a toner that has high low-temperature fixability and charging stability required in the POD range and that does not cause end portion contamination.A disclosed aspect of the present disclosure is directed to providing a toner including toner particles each containing a binder resin and a release agent and composite particles each present on a surface of each of the toner particles. The release agent has a penetration of 4 or less at 25° C. The composite particles include fine particles A each containing an organosilicon compound having a siloxane bond, the organosilicon compound serving as a binder component, and fine particles B formed of inorganic fine particles. Each of the fine particles B is partially embedded at the surface of each of the fine particles A. The following Expressions (1) to (3) are satisfied: wherein, in the fine particles A, based on the total silicon atoms contained in the silicon compound, Pa is the proportion of silicon atoms denoted by Si a, in a structure represented by the following unit (a), Pb is the proportion of silicon atoms denoted by Si b, in a structure represented by the following unit (b), and Pc is the proportion of silicon atoms denoted by Si c, in a structure represented by the following unit (c): wherein R 1 and R 2 are each an alkyl group having 1 or more and 6 or less carbon atoms. The fine particles B have a number-average primary particle diameter of 0.01 μm or more and 0.06 μm or less. In the composite particles, the average value of embedding ratios of the fine particles B to the fine particles A is 30% or more and 90% or less, each of the embedding ratios being represented by the following expression:Other features of the present disclosure will become apparent from the following description of exemplary embodiments.DESCRIPTION OF THE EMBODIMENTSIn an embodiment of the present disclosure, each of the expressions "XX or more and YY or less" and "XX to YY" refers to a numerical range including the lower limit and the upper limit, which are end points, unless otherwise specified. A toner according to an embodiment of the present disclosure includes toner particles and an external additive for toners. In the following description, the "toner particles" may also be referred to as "toner base particles".Features of the Present DisclosureThe inventors believe that the mechanism by which the effects of an embodiment of the present disclosure are manifested is described below.Heretofore, composite particles used as external additives for toners have excellent adhesion to toner particles on the basis. However, in a toner layer fixed on a medium, the adhesion of the composite particles may be insufficient. Since the external force of a conveying roller increases by the increase in speed of a copying machine, there is room for improvement from the viewpoint that the toner can be peeled from the medium to cause the end portion contamination.The inventors have made intensive studies and found that a toner according to an embodiment of the present disclosure can solve the above-mentioned problems by combining composite particles according to an embodiment of the present disclosure with a low-penetration release agent. This finding has led to the completion of the present disclosure. Although the mechanism is not clear, the inventors believe that, by fixing a toner according to an embodiment of the present disclosure containing the low-penetration release agent and the composite particles, the release agent leaks out at the surface layer of the fixed image to cover the surface of the fixed image with the release agent, resulting in the composite particles being partially hidden in the release agent. This results in a large contact area between the composite particles and the release agent on the surface of the fixed image.When the release agent fixing the composite particles has a certain hardness, the composite particles can be prevented from being peeled off on the fixed image by an external force.The composite particles have an irregular surface shape. Therefore, the contact area with the outside is smaller than that of external additive particles having the same primary particle diameter, whereby the effect of the external force can be reduced. In addition, when the composition of the binder of the composite particles is controlled within the range according to an embodiment of the present disclosure, the binder portion of the composite particles can reduce an external force applied to the composite particles.The inventors believe that the combination of the low-penetration release agent and the composite particles according to an embodiment of the present disclosure inhibits the detachment of the toner from the medium to prevent the occurrence of the end portion contamination.Composite Particles according to Embodiment of the Present DisclosureThe configuration of composite particles according to an embodiment of the present disclosure and a method for producing the composite particles will be described in detail below.The composite particles according to an embodiment of the present disclosure include fine particles A each containing an organosilicon compound having a siloxane bond, the organosilicon compound serving as a binder component, and fine particles B formed of inorganic fine particles.Each of the fine particles B is partially embedded at the surface of each of the fine particles A.The following Expressions (1) to (3) are satisfied: wherein, in the fine particles A, based on the total silicon atoms contained in the silicon compound, Pa is the proportion of silicon atoms denoted by Si a, in a structure represented by the following unit (a), Pb is the proportion of silicon atoms denoted by Si b, in a structure represented by the following unit (b), and Pc is the proportion of silicon atoms denoted by Si c, in a structure represented by the following unit (c): wherein R 1 and R 2 are each an alkyl group having 1 or more and 6 or less carbon atoms.The fine particles B have a number-average primary particle diameter of 0.01 μm or more and 0.06 μm or less. The average value of embedding ratios of the fine particles B to the fine particles A is 30% or more and 90% or less, each of the embedding ratios being represented by the following expression:The composite particles used in an embodiment of the present disclosure may have a number-average primary particle diameter of 0.03 μm or more and 0.30 μm or less. When the number-average primary particle diameter is within the above range, a fixed image can be uniformly covered with the external additive of the fine particles. This can reduce the load of the fixed image and easily provide the effect of preventing the end portion contamination.The number-average primary particle diameter of the composite particles can be increased by reducing the reaction temperature, shortening the reaction time, and increasing the catalyst amount in the hydrolysis and condensation step. The number-average primary particle diameter of the composite particles can be reduced by increasing the reaction temperature, extending the reaction time, and reducing the amount of catalyst in the hydrolysis and condensation step.The number-average primary particle diameter of the composite particles is preferably 0.07 μm or more and 0.20 μm or less, more preferably 0.08 μm or more and 0.15 μm or less, from the above viewpoint.The composite particles used in an embodiment of the present disclosure may have a Young's modulus of 10 GPa or more and 30 GPa or less. In a Young's modulus within the above range, when a fixed image is subjected to a load by a member such as a transport roller, the load may be released to further prevent the detachment of the external additive from the fixed image.At a Young's modulus of more than 10 GPa, the external additive itself is less likely to be damaged when a fixed image is subjected to a load by an element such as a transport roller. At a Young's modulus of less than 30 GPa, the stress may be easily relieved when a fixed image is loaded by a member such as a transport roller to further prevent the detachment of the external additive from the surface of the fixed image. The composite particles may have a Young's modulus of 13 GPa or more and 20 GPa or less to prevent end portion fouling.The Young's modulus of the composite particles used in an embodiment of the present disclosure can be controlled by changing the mixing ratio of the alkoxysilanes having the above structures (a) to (c) and the temperature, time, pH and kind of the catalyst in the hydrolysis and condensation step. Examples of a method for increasing the Young's modulus include an increase in the mixing proportion of an alkoxysilane having the structure (a), a decrease in the mixing proportion of alkoxysilanes having the structures (b) and (c), an increase in the temperature of the hydrolysis and condensation step, an increase in the time of the hydrolysis and condensation step, and an increase in the pH during the hydrolysis and condensation step. Examples of a method for reducing the Young's modulus include a reduction in the mixing proportion of an alkoxysilane having the structure (a), increases in the mixing proportions of alkoxysilanes having the structures (b) and (c), a reduction in the temperature of the hydrolysis and condensation step, a reduction in the time of the hydrolysis and condensation step, and a reduction in the pH during the hydrolysis and condensation step.With respect to the organosilicon compound having a siloxane bond in the fine particles A of the composite particles used in an embodiment of the present disclosure, the following Expressions (1) to (3) are satisfied: wherein Pa is the proportion of silicon atoms denoted by Si a, in a structure represented by the following unit (a), Pb is the proportion of silicon atoms denoted by Si b, in a structure represented by the following unit (b), and Pc is the proportion of silicon atoms denoted by Si c, in a structure represented by the following unit (c).Within the above ranges, the composite particles constituting the external additive are not easily damaged when a fixed image is loaded by a transport roller or the like. Moreover, appropriate flexibility of the external additive results in prevention of peeling of the external additive from the surface of the fixed image. Thus, the state of the surface of the fixed image is less likely to change, thereby preventing occurrence of end portion contamination. The proportions of the above-described units (a), (b) and (c) in the composite particles can be controlled by the amounts of alkoxysilanes having the respective structures added.The fine particles B of the composite particles used in an embodiment of the present disclosure may be inorganic fine particles having a Young's modulus of 50 GPa or more and 200 GPa or less. In a Young's modulus within the above range, the external additive itself is less likely to be damaged when a fixed image is subjected to a load by a member such as a transport roller, so that occurrence of end portion contamination is prevented.At least a portion of each fine particle B is embedded at the surface of each fine particle A. The average value of the embedding ratio is 30% or more and 90% or less. When the average value of the embedding ratio is within the above range, the fine particles B are less likely to peel off when a fixed image is loaded from a member such as a transport roller, thereby preventing occurrence of end portion contamination. The embedding ratio of the fine particles B can be controlled by the reaction time and the reaction temperature with the alkoxysilanes having the structures (a) to (c) above. Examples of a method for reducing the embedding ratio include a method in which the reaction time of the reaction between the alkoxysilanes and the fine particles B is decreased; and a method in which the reaction temperature is decreased. Examples of a method for increasing the embedding ratio include a method in which the reaction time of the reaction between the alkoxysilanes and the fine particles B is increased; and a method in which the reaction temperature is increased.When fine particles containing an organosilicon compound having a siloxane bond as a binder component, the fine particles being free from protrusions derived from the inorganic fine particles B, are used as an external additive in a toner, a desired anchoring effect originating from the protrusions cannot be provided, whereby the fine particles are not firmly bonded to the release agent. Fine particles in which inorganic fine particles B are completely embedded in fine particles containing an organosilicon compound as a binder component are considered to have no protrusions. Such fine particles cannot be firmly bonded to the release agent for the same reason. When non-spherical inorganic fine particles composed of, for example, silica are used in a toner, they may be fixed on a fixed image depending on the shape. However, when a fixed image is subjected to a load by a member such as a transport roller, the load cannot be released, so that detachment from the fixed image is not prevented.Methods for measuring the various physical properties described above will be described below.Production MethodA method for producing the composite particles used in an embodiment of the present disclosure is not limited to a specific method, but the particles may be formed by a sol-gel method by hydrolysis and a polycondensation reaction of a silicon compound (silane monomer). Specifically, a mixture of a difunctional silane having two siloxane bonds and a tetra-functional silane having four siloxane bonds is subjected to hydrolysis and polycondensation, and then allowed to react with colloidal silica or the like, resulting in the formation of composite particles. Silane monomers such as difunctional silanes and tetra-functional silanes are described below. The proportion of the difunctional silane is preferably 30 mol % or more and 70 mol % or less, more preferably 40 mol % or more and 60 mol % or less. The proportion of the tetra-functional silane is preferably 30 mol % or more and 70 mol % or less, more preferably 40 mol % or more and 70 mol % or less.The composite particles used in an embodiment of the present disclosure include, as a main portion, particles (fine particles A) composed of an organosilicon compound having a siloxane bond as a binder.A method for manufacturing a silicon compound according to an embodiment of the present disclosure is not limited to a specific method. For example, a silane compound may be added dropwise to water to perform hydrolysis and a condensation reaction in the presence of a catalyst, and then the resulting suspension may be filtered and dried to obtain a silicon compound. The particle size can be controlled by the kind of the catalyst, the mixing ratio, the temperature for initiation of the reaction, the time of dropwise addition, etc. Non-limiting examples of the catalyst include acidic catalysts such as hydrochloric acid, hydrofluoric acid, sulfuric acid, and nitric acid; and basic catalysts such as aqueous ammonia, sodium hydroxide, and potassium hydroxide.The silicon compound according to an embodiment of the present disclosure may be produced by the following method. More specifically, the method may include a first step of preparing a hydrolyzate of a silicon compound, a second step of mixing the hydrolyzate with an aqueous alkaline medium and colloidal silica to effect a polycondensation reaction of the hydrolyzate with the colloidal silica, and a third step of mixing the polycondensate with an aqueous solution to form particles. In some cases, a hydrophobicizing agent may also be added.In the first step, in an aqueous solution in which an acidic or alkaline substance acting as a catalyst is dissolved in water, the silicon compounds are contacted with the catalyst by stirring, mixing or the like. As the catalyst, a known catalyst may be used. Specific examples of the catalyst include acidic catalysts such as acetic acid, hydrochloric acid, hydrofluoric acid, sulfuric acid and nitric acid; and basic catalysts such as aqueous ammonia, sodium hydroxide and potassium hydroxide.The amount of the catalyst used can be adjusted according to the kind of the silicon compound and the catalyst. The amount of the catalyst used is selected from the range of 1×10 -3 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the water used in the hydrolysis of the silicon compound.When the amount of the catalyst used is 1×10 -3 parts by mass or more, the reaction sufficiently proceeds. When the amount of the catalyst used is 1 part by mass or less, the concentration of the catalyst remaining as an impurity in the fine particles is low, and the catalyst is easily hydrolyzed. The amount of water used may be 2 mol or more and 15 mol or less per mol of the silicon compound. When the amount of water is 2 mol or more, the hydrolysis reaction sufficiently proceeds. When the amount of water is 15 mol or less, productivity is improved.The reaction temperature is not limited to a specific value. The reaction may be carried out at room temperature or with heating. The reaction can be carried out at a temperature of 10°C to 60°C, since a hydrolyzate can be obtained in a short time and a partial condensation reaction of the resulting hydrolyzate can be prevented. The reaction time is not limited to a specific value, and may be appropriately selected in consideration of the reactivity of the silicon compound used, the composition of the reaction liquid prepared by mixing the silicon compound, the acid, and the water, and the productivity.In the second step of the method for producing a silicon compound, the raw material solution prepared in the first step is mixed with an aqueous alkaline medium so that the particle precursor is subjected to a polycondensation reaction. This produces a polycondensation reaction liquid. The aqueous alkaline medium is a liquid prepared by mixing an alkaline component, water and optionally an organic solvent or the like.The alkaline component used in the aqueous alkaline medium is an alkaline component whose aqueous solution is basic and acts as a neutralizer for the catalyst used in the first step and as a catalyst for the polycondensation reaction in the second step. Examples of the alkaline component include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonia; and organic amines such as monomethylamine and dimethylamine.The amount of the alkaline component used is an amount that neutralizes the acid and effectively acts as a catalyst for the polycondensation reaction. For example, when ammonia is used as the alkaline component, the amount of the alkaline component used is normally selected from 0.01 parts by mass or more and 12.5 parts by mass or less based on 100 parts by mass of the mixture of water and the organic solvent.In the second step, an organic solvent may also be used for preparing an aqueous alkaline medium in addition to the alkaline component and water. Any organic solvent may be used as long as it is compatible with water. An organic solvent which dissolves at room temperature and normal pressure at least 10 g of water per 100 g can be used.Specific examples thereof include alcohols such as methanol, ethanol, n-propanol, 2-propanol and butanol; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane and hexanetriol; ethers such as ethylene glycol monoethyl ether, acetone, diethyl ether, tetrahydrofuran and diacetone alcohol; amide compounds such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone.Among the above-mentioned organic solvents, alcohol solvents such as methanol, ethanol, 2-propanol and butanol may also be used. From the viewpoint of hydrolysis and dehydration condensation reaction, the same alcohol as the alcohol formed by elimination may be selected as the organic solvent.In the third step, the polycondensate formed in the second step is mixed with the aqueous solution to form particles. The aqueous solution may be water, such as tap water or pure water. A water-compatible component such as a salt, an acid, an alkali, an organic solvent, a surfactant or a water-soluble polymer may be further added to the water. The temperature of the polycondensation reaction liquid and the aqueous solution when they are mixed is not limited to a particular value, and may be selected in the range of 5°C to 70°C in consideration of their compositions, productivity, etc.Any known method of recovering particles may be used. Examples include a method in which a suspended powder is skimmed off and a filtration method. The filtration process is suitable because of its ease of handling. Any method may be employed. Any known device such as a vacuum filtration device, a centrifugal filtration device, or a pressure filtration device may be selected. A filter paper, a filter, a filter cloth, etc. used for filtration are not particularly limited as long as they are industrially available, and they can be selected according to an apparatus to be used.The monomer to be used may be selected according to its compatibility with the solvent and the catalyst, its hydrolyzability and the like. Examples of the tetra-functional silane monomer having the above structure (a) include tetramethoxysilane, tetraethoxysilane and tetraisocyanatosilane, and among these, tetraethoxysilane may be used.Examples of the trifunctional silane monomer having the above structure (b) include methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxysilane, methylmethoxyethoxychlorosilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydimethoxysilane, methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxysilane, methylethoxymethoxyhydroxysilane, methyldiethoxyhydroxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, Propyltriacetoxysilane, propyltrihydroxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, hexyltrihydroxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, and phenyltrihydroxysilane. Among these, methyltrimethoxysilane may be used.Examples of the difunctional silane monomer having the above structure (c) include di-tert-butyldichlorosilane, di-tert-butyldimethoxysilane, di-tert-butyldiethoxysilane, dibutyldichlorosilane, dibutyldimethoxysilane, dibutyldiethoxysilane, dichlorodecylmethylsilane, dimethoxydecylmethylsilane, diethoxydecylmethylsilane, dichlorodimethylsilane, dimethoxydimethylsilane, diethoxydimethylsilane, and diethyldimethoxysilane. Among these, dimethyldimethoxysilane can be used.Other Physical Properties of Composite Particles According to the Embodiment of the Present DisclosureThe true specific gravity of the composite particles used in an embodiment of the present disclosure may be 1.00 g / cm 3 or more and 1.60 g / cm 3 or less. Within the above range, when the fixed image is subjected to a load by a member such as a transport roller, the detachment of the external additive from the fixed image and damage of the external additive itself can be prevented. The true specific gravity of the external additive can be controlled by the amount of the fine particles B added. The true specific gravity of the external additive for toners may be 1.20 g / cm 3 or more and 1.40 g / cm 3 or less.In an electron image obtained by photographing portions of the composite particles used in an embodiment of the present disclosure with a transmission electron microscope, wherein the area of a portion X of a particle of the photographed fine particles A is Sa and the total area of the fine particles B that are completely contained in the portion X and are in an unexposed state is Sb, the average value of Sb / Sa for 100 particles of the fine particles A is 0 or more and 0.50 or less. From the viewpoint of preventing end portion contamination, when a fixed image is subjected to a load by a member such as a transport roller, detachment of the external additive from the fixed image can be prevented. Sb / Sa can be controlled by the amount of the fine particles B added and the reaction time and reaction temperature of the reaction between the fine particles B and the monomer formed into the fine particles A.In the composite particles used in an embodiment of the present disclosure, the ratio BD / AD may be 0.05 or more and 0.70 or less when the number average primary particle diameter of the fine particles A is AD and the number average primary particle diameter of the fine particles B is BD. Within the above range, the adhesion of the external additive to the release agent on the fixed image surface can be increased from the viewpoint of preventing the end portion contamination. The number-average primary particle diameter of the fine particles A can be controlled by adjusting the reaction conditions in the hydrolysis and condensation step according to the above-mentioned method. The number-average primary particle diameter of the fine particles B is controlled by the selection of the fine particles to be added.The fine particles B of the composite particles used in an embodiment of the present disclosure may be silica fine particles or alumina fine particles. When the fine particles B are the above fine particles, they have an appropriate hardness so that the adhesion to the surface of a fixed image is increased. In this case, the fine particles can be used to prevent the end portion contamination. From the viewpoint of reactivity with the binder component forming the fine particles A, silica fine particles can be used. The silica fine particles used in an embodiment of the present disclosure are particles composed mainly of silica (i.e., SiO 2) and may be particles prepared using a silicon compound such as water glass or an alkoxysilane as a raw material, or may be particles prepared by grinding quartz.Specific examples thereof include silica particles prepared by a sol-gel method, silica particles precipitated by a precipitation method, aqueous colloidal silica particles, fumed silica particles prepared by a gas phase method, and fused silica particles. Among these, aqueous colloidal silica particles can be used from the viewpoints of reactivity with the binder component and dispersion stability. The aqueous colloidal silica particles are commercially available or can be prepared from a variety of starting materials by any of the known methods. The aqueous colloidal silica particles can be prepared from silica derived from an alkali silicate solution having a pH of about 9 to about 11, wherein the silicate anions undergo polymerization to produce silica particles having a desired average particle size in the form of an aqueous dispersion.The composite particles used in an embodiment of the present disclosure may be surface treated with a water repellent. The hydrophobicizing agent may be, but is not limited to, an organosilicon compound.Examples thereof include alkyl silazane compounds such as hexamethyldisilazane; alkylalkoxysilane compounds such as diethyldiethoxysilane, trimethylmethoxysilane, methyltrimethoxysilane, and butyltrimethoxysilane; fluoroalkylsilane compounds such as trifluoropropyltrimethoxysilane; chlorosilane compounds such as diethyldichlorosilane and trimethylchlorosilane; siloxane compounds such as octamethylcyclotetrasiloxane; and silicone oil and silicone varnish.The hydrophobization treatment of the composite particles used in an embodiment of the present disclosure makes it possible to prevent a change in electrostatic adhesion of the toner after a durability test. The composite particles used in an embodiment of the present disclosure may be surface-treated with at least one compound selected from the group consisting of alkyl silazane compounds, alkylalkoxysilane compounds, chlorosilane compounds, siloxane compounds, and silicone oils. From the above viewpoint, the composite particles used in an embodiment of the present disclosure may be surface-treated with an alkyl silazane compound.With respect to the organosilicon compound having a siloxane bond in the fine particles A of the composite particles used in an embodiment of the present disclosure, the following expressions (I) to (III) can be satisfied: wherein Pa is the proportion of silicon atoms denoted by Si a, in a structure represented by the following unit (a), Pb is the proportion of silicon atoms denoted by Si b, in a structure represented by the following unit (b), and Pc is the proportion of silicon atoms denoted by Si c, in a structure represented by the following unit (c).Within the above range, when a fixed image is subjected to a load by a member such as a transport roller, the detachment of the external additive from the fixed image and the damage of the external additive itself can be prevented. When the following expressions are satisfied, the amount of Si-CH 3, which is present in the external additive, can be optimized in view of preventing the end portion contamination.The amount of the composite particles used in an embodiment of the present disclosure is preferably 0.1 parts by mass or more and 20.0 parts by mass or less, more preferably 0.5 parts by mass or more and 15.0 parts by mass or less, and even more preferably 1.0 parts by mass or more and 10.0 parts by mass or less, based on 100 parts by mass of the toner particles, from the viewpoint of charge stability.When the amount of the composite particles contained is 0.1 parts by mass or more and 20.0 parts by mass or less, the detachment of the composite particles from a fixed image is prevented to provide the effect of preventing the end portion contamination.Release AgentThe toner according to an embodiment of the present disclosure contains the releasing agent. When the penetration of the release agent is 4 or less, the external additive can be fixed on the fixed image, thereby providing the effect of preventing the end portion contamination. Penetration of the release agent can be controlled by controlling the molecular weight and composition of the release agent.The amount of the releasing agent contained may be 3.0 parts by mass or more and 15.0 parts by mass or less, based on 100.0 parts by mass of the binder resin. Within this range, the detachment of the external additive from a fixed image is prevented to easily provide the effect of preventing the end portion contamination.Examples of release agents that can be used in an embodiment of the present disclosure include aliphatic hydrocarbon waxes such as polyethylene, polypropylene, olefin copolymers, and Fischer-Tropsch wax; oxidized waxes of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; waxes composed mainly of fatty acid esters such as carnauba wax, behenyl behenate, and montanate wax; and waxes in which the fatty acid esters have been partially or completely deoxidized such as deoxidized carnauba wax.In particular, aliphatic hydrocarbon waxes and ester waxes such as behenyl behenate may be used. Examples thereof include hydrocarbons produced by radical polymerization of alkylene under high pressure or by polymerization of alkylene under low pressure in the presence of a Ziegler catalyst or a metallocene catalyst; Fischer-Tropsch wax synthesized from coal or natural gas; paraffin wax; olefin polymers produced by pyrolysis of high molecular weight olefin polymers; synthetic hydrocarbon waxes produced from the distillation residue of hydrocarbons recovered from a synthesis gas containing carbon monoxide and hydrogen by the Arge process; or synthetic hydrocarbon waxes produced by hydrogenation thereof. Hydrocarbon waxes separated by a press sweating method, a solvent method, a vacuum distillation or a fractional crystallization method may be used. Among the paraffin waxes, n-paraffin wax and Fischer-Tropsch wax composed mainly of linear components are suitable from the viewpoint of permanent stability because they have a narrow molecular weight distribution.Specific examples of ester waxes that can be used include monoester waxes such as behenyl behenate, stearyl stearate, pentaerythritol tetrabehenate, pentaerythritol tetrastearate, Dipentaerythritoltetrastearat glycerin tribehenate, glycerin tristearate, diglycerol hexabehenate, stearyl sebacate, trimethylolpropane behenate, distearyl succinate, glycerin 1,2-hydrostearate, glycerin monobehenate and tristearyl citrate; and polyfunctional ester waxes. Among these waxes, behenyl behenate can be used from the viewpoints of prevention of end portion fouling and low temperature fixability.These waxes may be used alone or in combination of two or more.Toner ParticlesBinder resinThe toner particles used in an embodiment of the present disclosure may contain a known binder resin. Examples of the binder resin will be described below.Examples thereof include styrene-based resins, styrene-based copolymer resins, polyester resins, polyol resins, polyvinyl chloride resins, phenol resins, natural resin-modified phenol resins, natural resin-modified maleic acid resins, acrylic resins, methacrylic resins, polyvinyl acetate, silicone resins, polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumarone-indene resins, and petroleum-based resins. Styrene-based copolymer resins, polyester resins and hybrid resins in which polyester resins and styrene-based copolymer resins are mixed or partially reacted with each other may also be used. In particular, a polyester resin can be used from the viewpoints of preventing end portion fouling and improving charging stability. The components constituting the polyester resin will be described in detail. The following components may be used singly or in combination of two or more depending on the kind and application.Examples of a dibasic acid component constituting the polyester resin include the following dicarboxylic acids or derivatives thereof. Examples thereof include benzenedicarboxylic acids such as phthalic acid, terephthalic acid and isophthalic acid, anhydrides thereof such as phthalic anhydride and lower alkyl esters thereof; alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid, anhydrides and lower alkyl esters thereof; alkenylsuccinic acids and alkylsuccinic acids each having 1 or more and 50 or less carbon atoms on average, anhydrides thereof and lower alkyl esters thereof; and unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid and itaconic acid, anhydrides thereof and lower alkyl esters thereof. Examples of an alkyl group in the lower alkyl esters include a methyl group, an ethyl group, a propyl group and an isopropyl group.Examples of the dihydric alcohol component constituting the polyester resin will be described below.Examples thereof include ethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 1,4-cyclohexanedimethanol (CHDM), hydrogenated bisphenol A, bisphenol, and derivatives thereof represented by the formula (I-1), and diols represented by the formula (I-2): wherein in the formula (I-1), each R is an ethylene group or a propylene group, x and y are each an integer of 0 or more, and the average value of x+y is 0 or more and 10 or less, and wherein, in formula (I-2), each R' is an ethylene group or a propylene group, x' and y' are each an integer of 0 or more, and the average value of x' + y' is 0 or more and 10 or less.The polyester resin may contain, as a constituent component, a trivalent or higher valent carboxylic acid compound and a trivalent or higher valent alcohol compound in addition to the above-mentioned divalent carboxylic acid compound and divalent alcohol compound.Examples of the trivalent or higher valent carboxylic acid compounds include, but are not limited to, trimellitic acid, trimellitic anhydride, and pyromellitic acid. Examples of the trivalent or higher-valent alcohol compound include trimethylolpropane, pentaerythritol, and glycerol.The polyester resin may contain, in addition to the above-mentioned compounds, a monovalent carboxylic acid compound and a monovalent alcohol compound as constituent components. Specific examples of the monovalent carboxylic acid compound include palmitic acid, stearic acid, arachidonic acid and behenic acid. Further examples thereof include cerotic acid, heptacosanoic acid, montanic acid, melissic acid, lacceroic acid, tetraconthanoic acid and pentaconthanoic acid.Examples of monohydric alcohol compounds include behenyl alcohol, ceryl alcohol, melissyl alcohol and tetracontanol.In an embodiment of the present disclosure, any known method for producing a polyester may be used without limitation. For example, the above-mentioned dibasic carboxylic acid compound and dibasic alcohol compound are polymerized by an esterification reaction or an ester exchange reaction and a condensation reaction to produce a polyester resin. The polymerization temperature may be in the range of 180° C. or higher and 290° C. or lower, but is not limited thereto. In the polymerization for producing the polyester resin, for example, a polymerization catalyst such as a titanium-based catalyst, a tin-based catalyst, zinc acetate, antimony trioxide, or germanium dioxide may be used.The molecular weight of the binder resin in one embodiment of the present disclosure is preferably 4000 or more and 100000 or less, more preferably 6000 or more and 40000 or less, as measured from the molecular weight distribution by gel permeation chromatography (GPC). This results in good end portion contamination prevention, good charge stability and good low temperature fixability.The glass transition temperature Tg of the binder resin in one embodiment of the present disclosure is preferably 50° C. or higher, 70° C. or lower, more preferably 55° C. or higher, and 65° C. or lower, from the viewpoints of end portion fouling prevention, charging stability, and low-temperature fixability.The acid value of the binder resin may be 5.0 mgKOH / g or more in one embodiment of the present disclosure.The acid value may be 10.0 mgKOH / g or more from the viewpoints of end portion pollution prevention, charging stability and low-temperature fixability.Coloring AgentThe toner according to an embodiment of the present disclosure may be used as a one-component magnetic toner, a one-component non-magnetic toner, or a two-component non-magnetic toner.When the toner is used as a one-component magnetic toner, magnetic iron oxide particles can be used as a colorant. Examples of the material of the magnetic iron oxide particles contained in the one-component magnetic toner include magnetic iron oxides such as magnetite, maghemite, ferrite; magnetic iron oxides containing other metal oxides; metals such as Fe, Co and Ni; alloys of these metals with metals such as Al, Co, Cu, Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W and V; and mixtures thereof.The content of magnetic iron oxide particles may be 30 parts by mass or more and 150 parts by mass or less, based on 100 parts by mass of the binder resin.Examples of colorants used in a one-component non-magnetic toner and a two-component non-magnetic toner will be described below.Examples of black pigments that can be used include carbon blacks such as furnace black, channel black, acetylene black, thermal black and lamp black, and magnetic powders such as magnetite and ferrite.As a colorant for yellow color, a pigment or a dye may be used. Examples of the pigment include C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 23, 62, 65, 73, 74, 81, 83, 93, 94, 95, 97, 98, 109, 110, 111, 117, 120, 127, 128, 129, 137, 138, 139, 147, 151, 154, 155, 167, 168, 173, 174, 176, 180, 181, 183, and 191, and C.I. Vat Yellow 1, 3, and 20. Examples of the dye include C.I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, and 162. These may be used alone or in combination of two or more.As a coloring agent for cyan color, a pigment or a dye may be used. Examples of the pigment include C.I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 16, 17, 60, 62, and 66, C.I. Vat Blue 6, and C.I. Acid Blue 45. Examples of the dye include C.I. Solvent Blue 25, 36, 60, 70, 93, and 95.As a colorant for a magenta color, a pigment or a dye may be used. Examples of the pigment include C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57, 57:1, 58, 60, 63, 64, 68, 81, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, and 254, C.I. Pigment Violet 19, C.I. Vat Red 1, 2, 10, 13, 15, 23, 29, and 35. examples of the dye for magenta include oil-soluble dyes such as C.I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, and 122, C.I. Disperse Red 9, C.I. Solvent Violet 8, 13, 14, 21, and 27, and C.I. Disperse Violet 1; and basic dyes such as C.I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, and 40, and C.I. Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, and 28. In particular, pigment red 122 may be used.The colorant content may be 0.1 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the binder resin.Charge Control AgentIn the toner according to an embodiment of the present disclosure, a known charge control agent may be used. Examples of the known charge control agent include azo iron compounds, azo chromium compounds, azo manganese compounds, azo cobalt compounds, azo zirconium compounds, chromium compounds of carboxylic acid derivatives, zinc compounds of carboxylic acid derivatives, aluminum compounds of carboxylic acid derivatives, and zirconium compounds of carboxylic acid derivatives. The carboxylic acid derivative may be an aromatic hydroxycarboxylic acid. A charge control resin may also be used. One or more charge control agents may be used in combination as needed. The charge control agent may be added in an amount of 0.1 parts by mass or more and 10 parts by mass or less based on 100 parts by mass of the binder resin. Additional Inorganic Fine PowderIn the toner according to an embodiment of the present disclosure, an additional inorganic fine powder may also be used as needed in addition to the above-mentioned external additive for toners. The inorganic fine powder may be internally added to the toner particles or mixed as an external additive with the toner base particles. As the external additive, an inorganic fine powder composed of a material such as silica can be used. The inorganic fine powder may be hydrophobicized with a hydrophobicizing agent such as a silane compound, silicone oil or a mixture thereof.As the external additive for improving the flowability, inorganic fine powders having a specific surface area of 50 m 2 / g or more and 400 m 2 / g or less can be used. In order to achieve both improvement of the flowability and stabilization of the durability, inorganic fine particles having a specific surface area within the above range may be used in combination.The inorganic fine powder may be used in an amount of 0.1 parts by mass or more and 10.0 parts by mass or less based on 100 parts by mass of the toner particles. When the above range is satisfied, a stable effect is easily provided.Production MethodA method for producing the toner particles is not limited to a specific method. Any of known methods such as a suspension polymerization method, an emulsion aggregation method, a melt kneading method and a solution suspension method can be used.The resulting toner particles may be mixed with the external additive for toners according to an embodiment of the present disclosure and, if necessary, with an additional external additive to provide a toner. The toner particles may be mixed with the external additive for toners according to an embodiment of the present disclosure and an additional external additive using a device such as a double cone mixer, a V-type mixer, a drum mixer, a super mixer, a Henschel mixer, a Nauta mixer, a Mechano Hybrid (manufactured by Nippon Coke & Engineering Co., Ltd.), or a Nobilta (manufactured by Hosokawa Micron Corporation).CarrierThe toner according to an embodiment of the present disclosure may be mixed with a carrier and used as a two-component developer. As the carrier, a typical carrier such as ferrite or magnetite or a resin-coated carrier may be used. Magnetic material dispersed resin particles in which a magnetic material powder is dispersed in a resin component or porous magnetic particles containing a resin in their hollow portions may be used.Examples of a magnetic material component that can be used in the magnetic material dispersed resin particles include various iron compound magnetic particle powders such as iron oxide magnetic particle powders, for example, magnetite particle powder, maghemite particle powder, and these powders each containing at least one element selected from silicon oxide, silicon hydroxide, aluminum oxide, and aluminum hydroxide; magnetoplumbite type ferrite particle powders containing barium, strontium, or barium strontium; and spinel type ferrite particle powders containing at least one selected from manganese, nickel, zinc, lithium, and magnesium.In addition to the magnetic component, non-magnetic inorganic compound particle powders such as non-magnetic iron oxide particle powders, e.g., a hematite particle powder, non-magnetic water-containing iron hydroxide particle powders, e.g., a goethite particle powder, and non-magnetic inorganic compound particle powders, e.g., a titanium oxide particle powder, a silica particle powder, a talc particle powder, an alumina particle powder, a barium sulfate particle powder, a barium carbonate particle powder, a cadmium yellow particle powder, a calcium carbonate particle powder, and a zinc oxide particle powder may be used in combination with the magnetic iron compound particle powder.Examples of the material of the porous magnetic core particles include magnetite and ferrite.A specific example of ferrite is represented by the following general formula: (M1 2 O) x( M2 O) y( Fe 2 O 3) z wherein, in the above formula, M1 is a monovalent metal, M2 is a divalent metal, and when x + y + z = 1.0, x and y are each 0 ≤ (x, y) ≤ 0.8, and z is 0.2 < z < 1.0.In the formula, M1and M2may be at least one metal atom selected from the group consisting of Li, Fe, Mn, Mg, Sr, Cu, Zn, and Ca. Ni, Co, Ba, Y, V, Bi, In, Ta, Zr, B, Mo, Na, Sn, Ti, Cr, Al, Si, and rare earths may also be used.The resin-coated carrier includes magnetic carrier core particles and a resin coating layer covering the surface of each of the magnetic carrier core particles. Examples of a resin used in the resin coating layer include acrylic resins such as acrylate copolymers and methacrylate copolymers; styrene-acrylic resins such as styrene-acrylate copolymers and styrene-methacrylate copolymers; fluorine-containing resins such as polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymers, monochlorotrifluoroethylene polymers and polyvinylidene fluoride; silicone resins; polyester resins; polyamide resins; polyvinyl butyral; amino acrylate resins; ionomer resins; and polyphenylene sulfide resins. These resins may be used alone or in combination of two or more. Among them, particularly from the viewpoint of charge stability, a copolymer containing a methacrylate having an alicyclic hydrocarbon group may be used. Examples of the methacrylate having an alicyclic hydrocarbon group include cyclobutyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, cycloheptyl acrylate, dicyclopentenyl acrylate, dicyclopentanyl acrylate, cyclobutyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, dicyclopentenyl methacrylate, and dicyclopentanyl methacrylate. The alicyclic hydrocarbon group may be a cycloalkyl group. The alicyclic hydrocarbon group preferably has 3 to 10 carbon atoms, more preferably 4 to 8 carbon atoms. These may be used alone or in combination of two or more.In order to increase the charge stability, the resin coating layer may contain a macromonomer as a copolymerizable component to increase the adhesion between the magnetic carrier core particles and the resin coating layer and prevent the local peeling of the resin coating layer. A specific example of a macromonomer is represented by the following formula (B): wherein in formula (B), A is a polymer moiety of one or more compounds selected from the group consisting of methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, styrene, acrylonitrile and methacrylonitrile as polymerizable components, and R is 3 H or CH 3.Method for Measuring Physical PropertiesMethods for measuring various physical properties will be described below.Separation of Fine Particles and Toner Particles from TonerThe respective physical properties can also be measured by using fine particles separated from a toner by the following method.First, 200 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) is added to 100 mL of ion-exchanged water, and then dissolved on a hot water bath to prepare a concentrated sucrose solution. To prepare a dispersion, 31 g of the concentrated sucrose solution thus obtained and 6 ml of contaminon N (a 10 mass % aqueous solution of a neutral detergent for cleaning a precision meter, the solution having a pH of 7 and containing a nonionic surfactant, an anionic surfactant and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) are placed in a centrifuge tube. To this dispersion is added 1 g of the toner. The lumps of toner are broken with a spatula or the like.The centrifuge tube is shaken for 20 minutes with a shaker at 350 revolutions per minute. After shaking, the solution is transferred to a glass tube (50 mL) for a swing rotor and centrifuged for 30 minutes in a centrifuge at 3500 U / min. After centrifugation, the toner in the glass tube is in the uppermost layer and the fine particles in the aqueous solution in the lower layer. The lower aqueous solution is collected and centrifuged to separate sucrose from the fine particles, and the fine particles are collected. If necessary, centrifugation is repeated to sufficiently separate the particles. Then, the dispersion is dried and the fine particles are collected.When multiple external additives are included, the external additive according to an embodiment of the present disclosure may be selectively separated, e.g., by a centrifugal separation method.Method for Measuring Number-Average Primary Particle Diameter of External AdditiveThe number-average primary particle diameter of the external additive can be determined by measurement with a centrifugal sedimentation method. Specifically, 0.01 g of dry particles of the external additive are placed in a 25 mL glass vial, then 0.2 g of a 5% Triton solution and 19.8 g of RO water are added, thereby preparing a solution. A probe (tip end) of an ultrasonic disperser is immersed in the solution and ultrasonically dispersed at an output of 20 W for 15 minutes, thereby providing dispersion. Then, the number average primary particle diameter of the dispersion is measured with a centrifugal sedimentation particle size distribution meter DC24000 manufactured by CPS Instruments, Inc. The rotational speed of a disc is set to 18000 U / min and the true density to 1.3 g / cm 3. Prior to measurement, the instrument is calibrated with polyvinyl chloride particles having an average particle size of 0.476 μm.Method for Measuring Young's Modulus of External AdditiveThe Young's modulus of the external additive is determined by a microcompression test with the Hysitron PI 85L picoindenter (manufactured by Bruker).The Young's modulus (MPa) is calculated from the slope of a profile (load-displacement curve), a displacement (nm), and a test force (μN) obtained by measurement.Device and Clamping DeviceBasic system: Hysitron PI 85LMeasuring indenter: Circular flattening indenter having a diameter of 1 μmUsed SEM: Thermo Fisher Versa 3DSEM conditions: -10° Inclination, 13 pA at 10 keV measurement conditionsMeasurement mode: Displacement controlMaximum shift: 30 nmShift rate: 1 nm / secResidence time: 2 secondsRelease rate: 5 nm / secAnalytical MethodThe Hertzian analysis is applied to a curve obtained at the time of compression by 0 nm to 10 nm in the resulting load-displacement curve, so as to calculate the Young's modulus of the fine particles.Sample PreparationFine particles adhered to a silicon wafer are methods for measuring Young's modulus of fine particles BFirst, the composition of the fine particles B is identified. The measurement is performed with a scanning electron microscope "S-4800" (trade name: Hitachi, Ltd.). An external additive having a difference in image contrast between a portion derived from the fine particles B composed of an inorganic substance and a portion derived from the fine particles A composed of an organic substance is defined as an external additive for toners according to an embodiment of the present disclosure. An external additive that does not have the difference in image contrast is defined as an external additive that is not the external additive for toners according to an embodiment of the present disclosure, and is distinguished. In the inorganic fine particles B, higher brightness is observed.The external additive is viewed and the compositions of the fine particles A and the fine particles B are identified with an energy dispersive X-ray analyzer in a field of view with up to two million times magnification. After the composition of the fine particles B is identified, fine particles having the same composition are prepared as the fine particles B. Then, the same measurement as the measurement of the Young's modulus of the above-mentioned external additive is performed to determine the Young's modulus of the fine particles B.Method for Measuring Embedding Ratio of Fine Particles BThe external additive is sufficiently dispersed in a visible light curable resin (Aronix, LCR Series D800 manufactured by Toagosei Co., Ltd.), and then cured by short-wave light irradiation. The resulting cured product is cut with an ultramicrotome equipped with a diamond knife to prepare a thin sample having a thickness of 250 nm. A portion of the external additive is observed by observing the cut sample with a transmission electron microscope (electron microscope JEM-2800 (TEM-EDX) manufactured by JEOL Ltd.) at a magnification of 40000× to 50000×. The diameter of a fine particle B and the embedding depth of the fine particle B in a fine particle A are measured from the sectional image. Among the fine particles B, five particles are randomly selected for one particle of the external additive. The embedding ratio of each of the fine particles B is calculated according to the following formula. The number of the analyzed external additive particles is 20 or more. The average value is defined as the embedding ratio of the fine particles B.Method for Measuring Sb / Sa of External AdditiveThe portion of the external additive is observed according to the above-mentioned method, and Sb / Sa of the external additive is calculated by image analysis. Image analysis software such as ImageJ is used. From an image obtained by the observation, the area Sa of the portion X of a particle of the fine particles A is calculated. Then, the total area Sb of the fine particles B which are completely contained in the portion X and are in an unexposed state is calculated. The number of external additive particles analyzed is 100, and the average value was defined as the value of Sb / Sa in an embodiment of the present disclosure.Method for Measuring BD / AD of External AdditiveThe portion of the external additive is considered according to the above method, and the BD / AD of the external additive is calculated. The particle sizes of the fine particles A and the fine particles B are calculated from the images obtained by observation. The number of analyzed particles of the external additive is 20, and the average value is defined as the value of BD / AD in an embodiment of the present disclosure.Method for measuring the constituent compound content of an external additive by solid 29Si-NMRIn the solid state 29 Si-NMR, peaks are detected in different shift ranges according to the structure of a functional group bonded to Si in the constituent compound of the external additive. Each peak position is identified from a standardized sample to identify the corresponding Si-bonded structure. From the resulting peak area, the proportion of the constituent compound present in each case can be calculated. The proportions of the peak areas of an M unit structure, a D unit structure (c), a T unit structure (b) and a Q unit structure (a) in the total peak area can be obtained by calculation.The specific measurement conditions for the solid state 29 Si-NMR will be described below.Apparatus: JNM-ECX5002 (JEOL RESONANCE Co., Ltd.)Temperature: room temperatureMethod for measurement: DD / MAS method 29 Si 45°Sample tube: zirconia ø3.2 mmSample: Filled in powder form in a test tubeSample rotation speed: 10 kHzRelaxation retardation: 180 secScan: 2000 scansAfter the measurement, the peaks of the different silane components having different substituents and bonding groups in the sample are separated by curve fitting into the following M unit structure, D unit structure (c), T unit structure (b) and Q unit structure (a), and the respective peak areas are calculated.The curve fitting is performed with EXcalibur for Windows (registered trademark), version 4.2 (EX series) of software for JNM-EX400 of JEOL Ltd. "1D Pro" is clicked in the menu icon to read the measurement data. Then, the function "curve fitting function" is selected from the menu "command" in the menu bar to perform the curve fitting. The curve fitting is performed for each component so as to minimize the difference (composite peak difference) between a composite peak obtained by combining the peaks obtained by the curve fitting and a peak of the measurement result. M unit structure: (Ra)(Rb)(Rc)SiO 1 / 2 D unit structure: (Rd)(Re)Si(O 1 / 2)2( c) T unit structure: RfSi(O 1 / 2)3( b)) Q unit structure: Si(O 1 / 2)4( a)In the formulae, Ra, Rb, Rc, Rd, Re and Rf are each an organic group such as a hydrocarbon group having 1 or more and 6 or less carbon atoms (e.g., an alkyl group or an alkoxy group), a halogen atom or a hydroxy group, the organic group being bonded to silicon. The proportions of (a), (b) and (c) in the external additive are calculated from the peak area corresponding to the structure represented by the formula (a), the peak area corresponding to the structure represented by the formula (b) and the peak area corresponding to the structure represented by the formula (c), these peak areas being determined by the measurement. When the structure needs to be examined in more detail, the results of 13 C-NMR and 1 H-NMR can be used in addition to the results of 29 Si-NMR to identify the structure.Method for Measuring True Specific Gravity of External AdditiveThe true specific gravity of the external additive is measured with an automatic densitometer in dry mode, the autopycnometer (manufactured by Yuasa Ionics). The conditions are described below.Cell: SM cell (10 mL)Amount of sample: 0.05 gThis measurement method is based on the gas displacement method, and the true specific gravity of solids and liquids is measured by this method.As with the liquid displacement method, the method is based on the Archimedes principle. However, a gas (argon gas) is used as the displacement medium; therefore, the method has high accuracy for micropores.Method for Measuring External Additive Surface Treatment AgentThe surface treatment agent for the external additive is analyzed by pyrolysis GC-MS (gas chromatography-mass spectrometry). The measurement conditions will be described in detail below.Apparatus: GC6890A (manufactured by Agilent Technologies, Inc.), Pyrolyzer (manufactured by Japan Analytical Industry Co., Ltd.)Column: HP-5ms, 30mPyrolysis temperature: 590° CThe position of each peak in a profile obtained by the measurement is identified from a standard sample, thereby identifying the surface treatment agent of the external additive.Separation of the Releasing Agent from the TonerThe various physical properties can also be measured using the release agent separated from the toner according to the following method.First, 200 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) is added to 100 mL of ion-exchanged water, and then dissolved on a hot water bath to prepare a concentrated sucrose solution. To prepare a dispersion, 31 g of the concentrated sucrose solution thus obtained and 6 ml of contaminon N (a 10 mass % aqueous solution of a neutral detergent for cleaning a precision meter, the solution having a pH of 7 and containing a nonionic surfactant, an anionic surfactant and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) are placed in a centrifuge tube. To this dispersion is added 1 g of the toner. The lumps of toner are broken with a spatula or the like.The centrifuge tube is shaken for 20 minutes with a shaker at 350 revolutions per minute. After shaking, the solution is transferred to a glass tube (50 mL) for a swing rotor and centrifuged for 30 minutes in a centrifuge at 3500 U / min. After centrifugation, the toner in the glass tube is in the uppermost layer and the fine particles in the aqueous solution in the lower layer. The top toner is collected, dried and dispersed in hexane. The mixture is stirred at 25 °C for 24 hours. The dispersion is filtered. The hexane solution is recovered and evaporated to collect the separation agent.Method for Measuring Penetration of Release AgentsThe penetration of the release agent in one embodiment of the present disclosure is a value measured according to JIS K-2207. This is a numerical value expressed in 0.1 mm units for the penetration depth when an indenter having a diameter of about 1 mm and a conical tip having a peak angle of 9 ° is penetrated into a sample under a fixed load. The test conditions in an embodiment of the present disclosure include a sample temperature of 25° C., an applied load of 100 g, and a penetration time of 5 seconds.Method for Measuring Acid Value of Binder ResinThe acid value is the number of milligrams of potassium hydroxide required to neutralize acidic components such as a free fatty acid and a resin acid contained in 1 g of a sample. The acid value is measured according to JIS K0070-1992 as described below.(1) ReagentFirst, 1.0 g of phenolphthalein is dissolved in 90 mL of ethyl alcohol (95 vol %). The solution is diluted to 100 mL with ion-exchanged water to form a phenolphthalein solution.7 g of special-quality potassium hydroxide are then dissolved in 5 ml of water. The solution is diluted to 1 L with ethyl alcohol (95 vol %). The solution thus obtained is placed in an alkali resistant container to avoid contact with, for example, carbon dioxide gas, and allowed to stand for three days. Then, the solution is filtered to provide a potassium hydroxide solution. The resulting potassium hydroxide solution is stored in an alkali-resistant container. 25 ml of 0.1 mol / l hydrochloric acid are introduced into an Erlenmeyer flask. To this is added several drops of phenolphthalein solution. The titration is carried out with the potassium hydroxide solution. The factor of the potassium hydroxide solution is determined from the amount of the potassium hydroxide solution required for neutralization. The 0.1 mol / L-acid used is prepared according to JIS K 8001-1998.(2) Operation(A) Main Test2.0 g of a ground sample are accurately weighed into a 200 ml Erlenmeyer flask. Then, 100 mL of a mixed solution of toluene and ethanol (2:1) is added. The sample is dissolved within 5 hours. A few drops of phenolphthalein solution are added as an indicator. The titration is carried out with the potassium hydroxide solution. The titration is complete when the light crazier color of the indicator continues for about 30 seconds.(B) Blank TestTitration is carried out in the same manner as described above except that no sample is used (i.e., only the mixed solution of toluene and ethanol (2:1) is used).(3) The results obtained are inserted into the following equation for calculating the acid number: wherein A is the acid number (mgKOH / G), B is the amount (mL) of the potassium hydroxide solution added in the blank test, C is the amount (mL) of the potassium hydroxide solution added in the main test, f is the factor of the potassium hydroxide solution, and S is the mass of the sample (g).Measurement of the Acid Number of Polyester Resins from TonerThe acid value of the polyester resin of the toner can be measured by the following method. The polyester resin is separated from the toner by the following method and the acid value is measured.The toner is dissolved in tetrahydrofuran (THF). From the resulting soluble fraction, the solvent is distilled off under reduced pressure to obtain a THF-soluble component of the toner.The resulting THF-soluble component of the toner is dissolved in chloroform to prepare a sample solution having a concentration of 25 mg / ml.Into the following apparatus, 3.5 ml of the resulting sample solution is injected. A component having a molecular weight of 2000 or more is separated as a resin component under the following conditions.Preparative gel permeation chromatograph: Preparative HPLC LC-980 manufactured by Nippon Analytical Industry Co., Ltd.Preparative columns: JAIGEL 3H and JAIGEL 5H (manufactured by Nippon Analytical Industry Co., Ltd.)Eluent: chloroformFlow rate: 3.5 mL / minThe high molecular weight component derived from the resin is fractionated. The solvent is distilled off under reduced pressure. Drying is carried out under reduced pressure at 90°C for 24 hours. The above-described procedure is repeated until about 2.0 g of the resin component is obtained.The resulting sample is used to measure the acid number according to the method described above.Measurement of Glass Transition Temperature (Tg) of Binder ResinThe glass transition temperature of the binder resin is measured according to ASTM D3418-82 with a differential scanning calorimeter "Q2000" (manufactured by TA Instruments).The temperature at the detection unit of the apparatus is corrected based on the melting points of indium and zinc. The amount of heat is corrected based on the heat of fusion of indium.Specifically, about 3 mg of a resin or a toner is accurately weighed and placed in an aluminum dish. The measurement is performed using an empty aluminum dish as a reference under the following conditions.Heating rate: 10° C. / minMeasurement start temperature: 20° CMeasurement end temperature: 180° CThe measurement is performed in the measurement range of 20° C. to 180° C. at a heating rate of 10° C. / min. The temperature is raised once to 180° C., held for 10 minutes, reduced to 20° C. and then raised again. In the second temperature raising process, a change in specific heat in the temperature range of 20° C. to 100° C. is obtained. The temperature at the intersection of the thermal difference curve and a straight line equidistant along the vertical axis from the "base line before the occurrence of the specific heat change" and the "base line after the occurrence of the specific heat change" is defined as the glass transition temperature (Tg, also referred to as the "center glass transition temperature") of the resin.Molecular Weight Measurement of Binder Resin and TonerThe molecular weight distribution of the THF-soluble fraction of the binder resin and the toner is measured by gel permeation chromatography (GPC) as described below.The toner is dissolved in THF for 24 hours at room temperature to prepare a solution. The resulting solution is filtered through a solvent-resistant membrane filter (trade name "Maeshori Disc", manufactured by Tosoh Corporation) having a pore size of 0.2 μm to prepare a sample solution. The sample solution is adjusted so that the concentration of THF-soluble components is about 0.8 mass %. The sample solution is used for measuring the molecular weight under the following conditions.Apparatus: HLC-8120 GPC (detector: RI) (manufactured by Tosoh Corporation)Column: Connection of seven columns of Shodex KF-801, 802, 803, 804, 805, 806 and 807 (manufactured by Showa Denko K.K.)Eluent: THFFlow rate: 1.0 mL / minOven temperature: 40.0°CSample injection volume: 0.10 mLTo calculate the molecular weight of a sample, a molecular weight calibration curve prepared using, for example, the following standard polystyrene resins manufactured by Tosoh Corporation is used. Standardized polystyrene resin: trade name "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000 and A-500"Method for Measuring Weight Average Particle Size (D4) of Toner ParticlesFor the measurement, a precision particle size distribution measuring apparatus (a Coulter Counter Multisizer 3 (registered trademark), manufactured by Beckman Coulter) equipped with a 100 μm aperture tube and based on an aperture impedance method and related software for the measuring apparatus (Beckman Coulter Multisizer 3 version 3.51, manufactured by Beckman Coulter) are used for setting the measurement conditions and analyzing the measurement data. The measurement is performed with 25000 effective measurement channels. The measurement data is evaluated to calculate the weight average particle size (D4) of the toner particles.As the aqueous electrolyte solution for measurement, a solution prepared by dissolving special-grade sodium chloride in ion-exchanged water in a concentration of about 1 mass %, such as "ISOTON II" (manufactured by Beckman Coulter), may be used.The dedicated software was set up as follows before performing the measurement and analysis.On the screen "Change standard operating method (SOM)" of the dedicated software, the total count in the control mode is set to 50000 particles, the number of measurements is set to 1, and the Kd value is set to the value obtained with "Standard Particles 10.0 μm" (manufactured by Beckman Coulter). By pressing the threshold / noise level measurement key, the threshold and noise level are automatically adjusted. The current is set to 1600 μA, the gain to 2, the electrolyte solution to ISOTON II, and the option "Flush aperture tube after measurement" is activated.On the conversion from pulse to particle size screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm or more and 60 μm or less.The specific method of measurement is described below.(1) About 200 mL of the aqueous electrolyte solution is placed in a 250 mL round bottom beaker prepared exclusively for the multisizer 3. The beaker is placed on a sample stand. Stirring is carried out with a counter-clockwise stirring rod at 24 revolutions per second. The function "aperture tube flush" of the associated software is executed in order to remove dirt and air bubbles in the aperture tube.(2) About 30 mL of the aqueous electrolyte solution is placed in a 100 mL flat bottom beaker. About 0.3 mL of the diluted solution of contaminon N (a 10 mass % aqueous solution of a neutral detergent for cleaning a precision meter, the solution having a pH of 7 and containing a nonionic surfactant, an anionic surfactant and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted three times by mass with ion-exchanged water is added as a dispersant.(3) An ultrasonic disperser (Ultrasonic Dispersion System Tetora 150 manufactured by Nikkaki Bios Co., Ltd.) is provided, wherein the disperser has an electric power of 120 W and includes two built-in oscillators having an oscillation frequency of 50 kHz and phases of which are shifted by 180° from each other, and a water tank. A certain amount of ion-exchanged water is placed in a water tank, and then 2 mL of the contaminon N is placed in this water tank.(4) The beaker described in (2) is placed in a beaker holder of the ultrasonic disperser, and then the ultrasonic disperser is operated. The height position of the cup is adjusted so as to maximize the resonance state of the liquid surface of the aqueous electrolyte solution in the cup.(5) About 10 mg of the toner is gradually added to the aqueous electrolyte solution and dispersed while the aqueous electrolyte solution is sonicated with ultrasonic waves in the beaker described in (4). The ultrasonic dispersing treatment is continued for an additional 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is suitably set to 10° C. or higher and 40° C. or lower.(6) The aqueous electrolyte solution described in (5) in which the toner has been dispersed is added dropwise with a pipette to the round bottom beaker described in (1) placed on the sample stand. The measurement concentration is set to about 5%. The measurement is continued until the number of the measured particles reaches 50000.(7) The measurement data is analyzed with the dedicated software provided to the apparatus to calculate the weight average particle size (D4). When the dedicated software is set to graph / volume %, the average size on the analysis / volume statistics (arithmetic mean) screen is the weight average particle size (D4).ExamplesThe basic configuration and features of the present disclosure have been described above. The present disclosure will be described in more detail below by way of examples. However, the present disclosure is not limited to these examples. Unless otherwise stated, part(s) and % are based on the mass.Production Example of Composite Particles C11. Hydrolysis and Polycondensation Step(1) In a 500 mL beaker were placed 21.6 g of RO water, 135.0 g of methanol, 0.004 g of acetic acid as catalyst and 12.2 g of dimethyldimethoxysilane. The mixture was stirred at 45°C for 5 minutes.(2) To the mixture are added 2.0 g of 28% aqueous ammonia, 15.0 g of tetraethoxysilane, and 5.0 g of aqueous colloidal silica dispersion A (silica solid content: 40% by mass, number-average particle size of silica: 40 nm (0.04 μm)). The mixture was stirred at 30° C. for 3.0 hours to prepare a raw material solution.2. Granulation stepFirst, 120.0 g of RO water was placed in a 1000 mL beaker. The raw material solution prepared in the hydrolysis and polycondensation step was added dropwise at 25° C. over a period of 5 minutes with stirring. The mixture was heated to 60° C. and stirred for 1.5 hours while maintaining the temperature at 60° C., thereby preparing a dispersion of external additive fine particles.3. Hydrophobicizing StepTo the dispersion of the external additive fine particles prepared in the above-described granulation step, 6.0 g of hexamethyldisilazane as a hydrophobicizing agent was added. The mixture was stirred at 60 °C for 3.0 hours. The mixture was allowed to stand for 5 minutes. The resulting powder precipitated at the bottom of the solution was collected by suction filtration and dried at 120°C under reduced pressure for 24 hours to give composite particles C1. The number-average primary particle diameter of the composite particles C 1 was 0.12 μm. Further physical properties are listed in Table 1.Production Example of Composite Particles C2Composite particles C2 were prepared in the same manner as in the preparation example of composite particles C1, except that in (1) of the hydrolysis and polycondensation step, the amount of dimethyldimethoxysilane was changed to 5.0 g, and in (2) the amount of tetraethoxysilane was changed to 10.2 g, and 12.0 g of trimethoxymethylsilane was added.Production Example of Composite Particles C3Composite particles C3 were prepared in the same manner as in the preparation example of composite particles C1, except that in (1) of the hydrolysis and polycondensation step, the amount of dimethyldimethoxysilane was changed to 7.2 g and in (2) the amount of tetraethoxysilane was changed to 20.0 g.Production Example of Composite Particles C4Composite particles C4 were prepared in the same manner as in the preparation example of composite particles C1, except that in (1) of the hydrolysis and polycondensation step, the amount of dimethyldimethoxysilane was changed to 16.0 g and in (2) the amount of tetraethoxysilane was changed to 11.2 g.Production Example of Composite Particles C5Composite particles C5 were prepared in the same manner as in the preparation example of composite particles C1, except that in (1) of the hydrolysis and polycondensation step, the amount of dimethyldimethoxysilane was changed to 7.2 g, and in (2), no tetraethoxysilane but 20.0 g of trimethoxymethylsilane was added. Production Example of Composite Particles C6Composite particles C6 were prepared in the same manner as in the preparation example of composite particles C1, except that in (1) of the hydrolysis and polycondensation step, dimethyldimethoxysilane and 5.4 g of trimethoxymethylsilane were not added, and in (2), the amount of tetraethoxysilane was changed to 22.0 g.Production Example of Composite Particles C7Composite particles C 7 were prepared in the same manner as in the preparation example of composite particles C 1, except that in (2) of the hydrolysis and polycondensation step, an aqueous colloidal silica dispersion B (silica solid content: 40 mass %, number-average particle size of silica: 20 nm (0.02 μm)) was used instead of the aqueous colloidal silica dispersion A, the amount of 28% aqueous ammonia was changed to 3.0 g, and the stirring temperature was changed to 25° C.Production Example of Composite Particles C8Composite particles C8 were produced in the same manner as in the production example of composite particles C1, except that in (2) of the hydrolysis and polycondensation step, the amount of 28% aqueous ammonia was changed to 1.0 g and the stirring temperature was changed to 40° C.Production Example of Composite Particles C9Composite particles C 9 were prepared in the same manner as in the preparation example of composite particles C 1, except that in (2) of the hydrolysis and polycondensation step, an aqueous colloidal silica dispersion C (silica solid content: 40 mass %, number-average particle size of silica: 10 nm (0.01 μm)) was used instead of the aqueous colloidal silica dispersion A, the amount of 28% aqueous ammonia was changed to 3.0 g, and the stirring temperature was changed to 25° C.Production Example of Composite Particles C10Composite particles C10 were prepared in the same manner as in the preparation example of composite particles C1, except that in (2) of the hydrolysis and polycondensation step, the amount of 28% aqueous ammonia was changed to 1.0 g, the stirring temperature was changed to 40° C., and the stirring time was changed to 3.5 hours.Production Example of Composite Particles C11Composite particles C 11 were produced in the same manner as in the production example of composite particles C 1, except that in (2) of the hydrolysis and polycondensation step, an aqueous alumina dispersion (alumina solid content: 30 mass %, number-average particle size of alumina: 40 nm (0.04 μm)) was used instead of the aqueous colloidal silica dispersion A.Production Example of Composite Particles C12Composite particles C12 were prepared in the same manner as in the preparation example of composite particles C1, except that in (2) of the hydrolysis and polycondensation step, the amount of the aqueous colloidal silica dispersion A added was changed to 10.0 g.Production Example of Composite Particles C13Composite particles C13 were prepared in the same manner as in the preparation example of composite particles C1, except that in (2) of the hydrolysis and polycondensation step, the amount of the aqueous colloidal silica dispersion A added was changed to 15.0 g.Production Example of Composite Particles C14Composite particles C14 were prepared in the same manner as in the preparation example of composite particles C1, except that in (2) of the hydrolysis and polycondensation step, the amount of 28% aqueous ammonia was changed to 5.0 g, the stirring temperature was changed to 25° C., and the stirring time was changed to 2.0 hours.Production Example of Composite Particles C15Composite particles C 15 were prepared in the same manner as in the preparation example of composite particles C 1, except that in (2) of the hydrolysis and polycondensation step, an aqueous colloidal silica dispersion B (silica solid content: 40 mass %, number-average particle size of silica: 10 nm (0.01 μm)) was used instead of the aqueous colloidal silica dispersion A, the amount of 28% aqueous ammonia was changed to 1.0 g, the stirring temperature was changed to 45° C., and the stirring time was changed to 4.0 hours.Production Example of Composite Particles C16Composite particles C 16 were prepared in the same manner as in the preparation example of composite particles C 1, except that in (2) of the hydrolysis and polycondensation step, an aqueous colloidal silica dispersion C (silica solid content: 40 mass %, number-average particle size of silica: 70 nm (0.07 μm)) was used instead of the aqueous colloidal silica dispersion A, the amount of 28% aqueous ammonia was changed to 1.0 g, the stirring temperature was changed to 45° C., and the stirring time was changed to 4.0 hours.Production Example of Composite Particles C17Composite particles C17 were prepared in the same manner as in the preparation example of composite particles C1, except that 3.2 g of dimethyldimethoxysilane was added in (1) of the hydrolysis and polycondensation step and 24.0 g of tetraethoxysilane was added in (2).Production Example of Composite Particles C18In a 250 mL round bottom four-necked flask equipped with an overhead stirrer, a condenser, and a thermocouple, 18.7 g of colloidal silica dispersion (silica solid content: 40 mass %, number average particle size of silica: 30 nm (0.03 μm)), 125 mL of DI water, and 16.5 g (0.066 mol) of methacryloxypropyltrimethoxysilane were added. The temperature was raised to 65°C and the mixture was stirred at 120 U / min. Nitrogen gas was bubbled into the mixture for 30 minutes. After 3 hours, 0.16 g of 2,2'-azobis(isobutyronitrile) serving as a radical initiator dissolved in 10 ml of ethanol was added and the temperature was raised to 75 °C.Radical polymerization was carried out for 5 hours, then 3 mL of 1,1,1,3,3,3-hexamethyldisilazane was added to the mixture. The reaction was continued for an additional 3 hours. The final mixture was filtered through a 170 mesh screen to remove agglomerates. The dispersion was dried in a Pyrex dish (registered trademark) at 120°C overnight to obtain composite particles C18.Production Example of Composite Particles C19Composite particles C19 were prepared in the same manner as in the preparation example of composite particles C1, except that in (2) of the hydrolysis and polycondensation step, a dispersion of fine particles of a polyester resin (polyester resin solid content: 25 mass %, number average particle size of polyester resin: 50 nm (0.05 μm)) was used instead of the aqueous colloidal silica dispersion A.Production Example of Composite Particles C20In a 250 mL round bottom four-necked flask equipped with an overhead stirrer, a condenser, and a thermocouple, 18.7 g of colloidal silica dispersion (silica solid content: 40 mass %, number average particle size of silica: 30 nm (0.03 μm)), 125 mL of DI water, and 16.5 g (0.066 mol) of methacryloxypropyltrimethoxysilane were added. The temperature was raised to 65°C and the mixture was stirred at 120 U / min. Nitrogen gas was bubbled into the mixture for 30 minutes. After 3 hours, 0.16 g of 2,2'-azobis(isobutyronitrile) serving as a radical initiator dissolved in 10 ml of ethanol was added and the temperature was raised to 75 °C.Radical polymerization was carried out for 5 hours, then 3 ml of 1,1,1,3,3,3-hexamethyldisilazane was added to the mixture. The reaction was continued for an additional 3 hours. The final mixture was filtered through a 170 mesh screen to remove agglomerates. The dispersion was dried overnight in a Pyrex dish (registered trademark) at 120° C. to obtain composite particles C20.The physical properties of the composite particles C1 to C20 prepared as described above are shown in Table 1. Preparation Example of Binder Resin ABisphenol A propylene oxide adduct (2.2 moles of adduct): 100.0 mole parts of terephthalic acid: 90.0 mole partsIn a 5 L autoclave, 100 parts of the monomers constituting a polyester unit were mixed with 500 ppm of titanium tetrabutoxide.The above materials were weighed into a reaction vessel equipped with a condenser, a stirrer, a nitrogen inlet and a thermocouple.The air in the flask was replaced with nitrogen gas. The temperature was increased stepwise with stirring. The mixture was reacted at 200°C for 2 hours with stirring.In addition, the pressure in the reaction vessel was reduced to 8.3 kPa and maintained for 1 hour. The mixture was then cooled to 180°C. The pressure was brought to atmospheric pressure (first reaction step).Trimellitic anhydride: 15.0 parts by moleThe above material was added. The pressure in the reaction vessel was reduced to 8.3 kPa. The reaction was carried out while maintaining the temperature at 160°C. The reaction time was adjusted to achieve a desired molecular weight. The reaction was stopped by lowering the temperature (second reaction step). The reaction mixture was milled to provide binder resin A. Binder resin A had a Tg of 63°C and an acid number of 20.0 mgKOH / g. Further physical properties are listed in Table 2.Preparation Example of Binder Resin BBinder resin B was prepared in the same manner as in the preparation example of binder resin A except that the kinds and amounts of the monomers added were changed as shown in Table 2 and the reaction time was adjusted to change the molecular weight and the Tg. The physical properties of the resulting binder resin B are shown in Table 2. Table 2 Table 2Binder Resin A1009015-632065003,4Binder Resin B1008010106515360007,6BPA-PO propylene oxide adduct of bisphenol A (average molar amount added: 2.2 moles) TPA terephthalic acid TMA trimellitic anhydride AA adipic acidProduction Example of Toner Particles 1Polyester resin A: 70.0 partsPolyester resin B: 30.0 partsFischer-Tropsch wax (peak temperature of maximum endothermic peak: 90°C, penetration: 3): 6.0 partsPigment Red 122: 5.0 partsThe raw materials described in the above formulation were mixed with a Henschel mixer (FM-75 manufactured by Nippon Coke & Engineering Co., Ltd.) at a rotation speed of 20 sec -1 for a rotation time of 5 minutes. The mixture was then kneaded in a twin screw kneader (PCM-30 manufactured by Ikegai Co., Ltd.) at a temperature of 130°C and a rotational speed of 300 U / min. The resultant kneaded product was cooled and roughly crushed to a diameter of 1 mm or less with a hammer mill, thereby obtaining a roughly crushed product. The resulting roughly crushed product was finely ground with a mechanical grinder (T-250 manufactured by Freund-Turbo Corporation). Subsequently, classification was performed with a rotary classifier (200TSP manufactured by Hosokawa Micron Corporation) to obtain toner particles 1. With respect to the operating conditions of the rotary classifier (200TSP manufactured by Hosokawa Micron Corporation), classification was performed at a rotational speed of the classifying rotor of 50.0 s -1. The resulting toner particles 1 had a weight average particle size (D4) of 6.5 μm.Production Example of Toner 1Toner particles 1: 100 partsComposite particles C1: 5.0 partsThe above materials were mixed in a Henschel mixer, model FM-10C (manufactured by Mitsui Miike Chemical Engineering Machinery, Co., Ltd.) at a rotation speed of 30 sec -1 for a rotation time of 10 minutes to provide toner 1.Production Examples of Toner Particles 2 to 7Toner particles 2 to 7 were produced in the same manner as in the production example of toner particles 1, except that the kinds and amounts of the releasing agents were changed as shown in Table 3.Production Examples of Toners 2 to 29Toners 2 to 29 were produced in the same manner as in the production example of Toner 1, except that the kinds and amounts of the composite particles added were changed as shown in Table 3. Table 3 Table 3Toner 1Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C156,5Toner 2Toner Particles 2Binder Resin A70Binder Resin B30Behenyl behenate7226PR1225C156,5Toner 3Toner Particles 3Binder Resin A70Binder Resin B30Fischer-Tropsch10516PR1225C156,5Toner 4Toner Particles 4Binder Resin A70Binder Resin B30Fischer-Tropsch9033PR1225C156,5Toner 5Toner Particles 5Binder Resin A70Binder Resin B30Fischer-Tropsch90315PR1225C156,5Toner 6Toner Particles 6Binder Resin A70Binder Resin B30Fischer-Tropsch90320PR1225C256,5Toner 7Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C356,5Toner 8Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C456,5Toner 9Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C556,5Toner 10Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C656,5Toner 11Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C10,56,5Toner 12Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1206,5Toner 13Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C10,056,5Toner 14Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1216,5Toner 15Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C756,5Toner 16Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C856,5Toner 17Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C956,5Toner 18Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1056,5Toner 19Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1156,5Toner 20Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1256,5Toner 21Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1356,5Toner 22Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1456,5Toner 23Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1556,5Toner 24Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1656,5Toner 25Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1756,5Toner 26Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1856,5Toner 27Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C1956,5Toner 28Toner Particles 1Binder Resin A70Binder Resin B30Fischer-Tropsch9036PR1225C2056,5Toner 29Toner Particles 7Binder Resin A70Binder Resin B30Fischer-Tropsch7766PR1225C156,5Production Example of Support 1Magnetite 1 having a number average particle size of 0.30 μm (magnetization intensity of 65 Am 2 / kg under a magnetic field of 1000 / 4π (kA / m))Magnetite 2 having a number average particle size of 0.50 μm (magnetization intensity of 65 Am 2 / kg under a magnetic field of 1000 / 4π (kA / m))To 100 parts of each of the above materials, 4.0 parts of a silane compound (3-(2-aminoethylaminopropyl)trimethoxysilane) was added. The mixture was mixed and stirred in a vessel at 100° C. or higher at high speed, thereby treating the fine particles of the individual materials.Phenol: 10 mass %Formaldehyde solution: 6 mass % (40 mass % of formaldehyde, 10 mass % of methanol, and 50 mass % of water)Magnetite 1 treated with the above silane compound: 58% by massMagnetite 2 treated with the above silane compound: 26 mass%In a flask, 100 parts of the above-mentioned materials, 5 parts of a 28% by mass aqueous ammonia solution, and 20 parts of water were placed. The mixture was heated to 85°C for 30 minutes with stirring and mixing. The temperature was maintained at 85°C to conduct polymerization reaction for 3 hours, thereby curing the resulting phenol resin. The cured phenolic resin was cooled to 30°C. Water was added. The supernatant was removed. The precipitate was washed with water and then air dried. The resulting product was dried at 60 °C under reduced pressure (5 mmHg or less) to provide a magnetic material dispersed spherical support 1. The 50% particle size (D50) of the carrier on a volume basis was 34.2 μm.Production Example of Developer 1Toner 1 and Carrier 1 were mixed in a V mixer (Model V-10, Tokuju Corporation) at a rotation speed of 0.5 sec -1 and a rotation time of 5 minutes so that the mixture contained 90 parts of Carrier 1 and 10 parts of Toner 1, thereby preparing Two-component Developer 1.Production Examples of Developers 2 to 29Two-component developers 2 to 27 were prepared in the same manner as in the preparation example of developer 1 except that the toners shown in Table 4 were used. Examples 1 to 22 and Comparative Examples 1 to 7The resulting developers were evaluated as described below.Evaluation of End Portion Contamination PreventionThe resulting two-component developers were subjected to the following evaluations. As the image forming apparatus, a modified full color copier (trade name: imagePRESS C10000VP, manufactured by CANON KABUSHIKI KAISHA) was used. A two component developer was added to the magenta station developing unit. The copier was modified so that the process speed could be changed to 600 mm / sec.With the above-mentioned apparatus, 100000 images were output in a normal temperature and normal humidity environment (23° C., 50% r.f., hereinafter also referred to as "N / N environment"). The last 1000 sheets were stacked and visually examined for the presence of contaminants in the end portions.In the image output, the paper was transferred under the same developing conditions and transfer conditions (but without calibration) as the first sheet. The print rate of the output image was set to 30%. The developing bias voltage was adjusted so that the initial image density was 1.55. As the paper for evaluation, A4 size plain paper (trade name: CF-C081, basis weight: 81.4 g / m 2, Canon Marketing Japan Inc.) was used for copying.Criteria for EvaluationA: No end portion contamination is detected.B: There is an image suspected of end portion fouling, but it remains at a level at which it cannot be determined whether there is marked fouling.C: While very little contamination is observed, this is an acceptable level in one embodiment of the present disclosure.D: Contamination is observed that is unacceptable in one embodiment of the present disclosure.Evaluation of Charging StabilityAs the image forming apparatus, a modified full color copier (trade name: imagePRESS C10000VP, manufactured by CANON KABUSHIKI KAISHA) was used. A two component developer was added to the developing unit of a magenta station. The copier was modified so that the process speed could be changed to 600 mm / sec.With the above-mentioned apparatus, 100000 images were outputted in a high-temperature and high-humidity environment (30° C., 80% r.f., hereinafter also referred to as "H / H environment"). The density difference between the first sheet and the last sheet was evaluated.In the image output, the paper was transferred under the same developing conditions and transfer conditions (but without calibration) as the first sheet. The print rate of the output image was set to 8%. The developing bias voltage was adjusted so that the initial image density was 1.55. As the paper for evaluation, A4 size plain paper (trade name: CF-C081, basis weight: 81.4 g / m 2, Canon Marketing Japan Inc.) was used for copying.Evaluation CriteriaA: The density difference is 0.03 or less.B: The density difference is 0.06 or less.C: The density difference is 0.10 or less.D: The density difference is more than 0.10.Evaluation of Low Temperature FixabilityAs the image forming apparatus, a modified full color copier (trade name: imagePRESS C10000VP, manufactured by CANON KABUSHIKI KAISHA) was used. A two component developer was added to the developing unit of a magenta station. The copier was modified so that the process speed could be changed to 600 mm / sec. In addition, the copier was modified so that the fixing temperature was adjustable.With the above-mentioned apparatus, images were outputted in a low temperature and low humidity environment (20° C., 10% r.l., hereinafter also referred to as "L / L environment") while the fixing temperature was reduced. The temperature at which the cold offset occurred was visually evaluated.Each output image was a belt image extending from a position of 80 mm from the rear end of the paper to the rear end. The developing bias voltage was adjusted so that the toner amount of unfixed image was 1.00 mg / cm 2. As the paper for evaluation, A4 size plain paper (trade name: CF-C081, basis weight: 81.4 g / m 2, Canon Marketing Japan Inc.) was used for copying.Evaluation CriteriaAA: The minimum fixing temperature is less than 155° C.A: The minimum fixing temperature is 160° C. or less.B: The minimum fixing temperature is 170° C. or less.C: The minimum fixing temperature is 180° C. or less.D: The minimum fixing temperature is more than 180° C.The results of the above evaluations are shown in Table 4. Table 4 Table 4Example 1Developer 1Toner 1A. AA. A0,01A. A155Example 2Developer 2Toner 2A. AA. A0,03AA150Example 3Developer 3Toner 3A. AA. A0,03A. A155Example 4Developer 4Toner 4A. AA. A0,01A. A155Example 5Developer 5Toner 5A. AA. A0,02A. A155Example 6Developer 6Toner 6A. AA. A0,02A. A155Example 7Developer 7Toner 7A. AA. A0,03A. A155Example 8Developer 8Toner 8A. AA. A0,03A. A155Example 9Developer 9Toner 9B. BA. A0,03A. A160Example 10Developer 10Toner 10B. BA. A0,03A. A160Example 11Developer 11Toner 11B. BB. B0,04A. A160Example 12Developer 12Toner 12B. BB. B0,04A. A160Example 13Developer 13Toner 13B. BB. B0,05B. B165Example 14Developer 14Toner 14B. BB. B0,05B. B165Example 15Developer 15Toner 15C. CB. B0,06B. B165Example 16Developer 16Toner 16C. CB. B0,06B. B165Example 17Developer 17Toner 17C. CC. C0,07B. B170Example 18Developer 18Toner 18C. CC. C0,08B. B170Example 19Developer 19Toner 19B. BB. B0,04B. B165Example 20Developer 20Toner 20C. CC. C0,09C. C175Example 21Developer 21Toner 21C. CC. C0,09C. C175Example 22Developer 22Toner 22C. CC. C0,10C. C180Comparative Example 1Developer 23Toner 23D. DD. D0,11D. D185Comparative Example 2Developer 24Toner 24D. DD. D0,12C. C180Comparative Example 3Developer 25Toner 25D. DC. C0,10D. D185Comparative Example 4Developer 26Toner 26D. DD. D0,13C. C180Comparative Example 5Developer 27Toner 27D. DD. D0,14D. D185Comparative Example 6Developer 28Toner 28D. DD. D0,15D. D185Comparative Example 7Developer 29Toner 29D. DD. D0,16D. D185Although the present disclosure has been described with reference to exemplary embodiments, the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be construed as broadly as possible to include all such modifications and equivalent structures and functions.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 5982003 [0004, 0005]

Claims

A toner comprising: toner particles each containing: a binder resin, and a releasing agent; and composite particles each present on a surface of each toner particle, wherein the releasing agent has a penetration of 4 or less at 25°C, the composite particles including: fine particles A each containing an organosilicon compound having a siloxane bond, wherein the organosilicon compound serves as a binder component, and fine particles B formed of inorganic fine particles, each of the fine particles B being partially embedded on the surface of each of the fine particles A, the following expressions (1) to (3) are satisfied: Pa + Pb + Pc ≥ 0.80 Pb + Pc ≥ 0.30 Pa / (Pa + Pb + Pc ) ≤ 0.70 wherein in the fine particles A, based on the total silicon atoms contained in the silicon compound, Pa is a proportion of silicon atoms denoted by Si a, in a structure represented by the following unit (a), Pb is a proportion of silicon atoms denoted by Si b, in a structure represented by the following unit (b), and Pc is a proportion of silicon atoms denoted by Si c, in a structure represented by the following unit (c): wherein R 1 and R 2 are each an alkyl group having 1 or more and 6 or less carbon atoms, the fine particles B have a number-average primary particle diameter of 0.01 μm or more and 0.06 μm or less, and in the composite particles, an average value of embedding ratios of the fine particles B to the fine particles A is 30% or more and 90% or less, each of the embedding ratios being represented by the following expression: Each embedding ratio of each fine particle B to each fine particle A (%)=(an embedding depth of each fine particle B in each fine particle A / a diameter of each fine particle B)×100. The toner according to claim 1, wherein the composite particles have a number-average primary particle diameter of 0.03 μm or more and 0.30 μm or less.The toner according to claim 1 or 2, wherein the fine particles A have a true specific gravity of 1.00 g / cm 3 or more and 1.60 g / cm 3 or less.The toner according to any one of claims 1 to 3, wherein in an electron image obtained by photographing portions of the fine particles A with a transmission electron microscope, Sa is an area of a portion X of a particle of the photographed fine particles A, Sb is a total area of the fine particles B that are completely contained in the portion X and that are in an unexposed state, and an average value of Sb / Sa for 100 particles of the fine particles A is 0 or more and 0.50 or less.The toner according to any one of claims 1 to 4, wherein the fine particles B are silica fine particles or alumina fine particles.The toner according to any one of claims 1 to 5, wherein AD is a number-average primary particle diameter of the fine particles A, BD is the number-average primary particle diameter of the fine particles B, and a BD / AD ratio is 0.05 or more and 0.70 or less.The toner according to any one of claims 1 to 6, wherein the composite particles have a Young's modulus of 10 GPa or more and 30 GPa or less.The toner according to any one of claims 1 to 7, wherein the proportions Pa, Pb and Pc in the fine particles A satisfy the following expressions (I), (II) and (III): 0.30 ≤ Pa / ( Pa + Pb + Pc ) ≤ 0.70 0 ≤ Pb / ( Pa + Pb + Pc ) ≤ 0.50 0,20 ≤ Pc / ( Pa + Pb + Pc ) ≤ 0.70 The toner according to any one of claims 1 to 8, wherein the amount of the releasing agent contained is 3.0 parts by mass or more and 15.0 parts by mass or less, based on 100 parts by mass of the binder resin.The toner according to any one of claims 1 to 9, wherein X is an amount of the contained composite particles, Y is an amount of the contained releasing agent, and a ratio X / Y is 0.08 or more and 3.33 or less.The toner according to any one of claims 1 to 10, wherein the releasing agent is a hydrocarbon wax.The toner according to any one of claims 1 to 10, wherein the releasing agent is an ester wax.The toner according to any one of claims 1 to 12, wherein the amount of the composite particles contained in the toner is 0.5 parts by mass or more and 20.0 parts by mass or less, based on 100 parts by mass of the toner particles.