Toner

Abstract

The present invention relates to a toner. A toner comprising toner particles, wherein the toner particles have a core-shell structure comprising a core particle and a shell on the surface of the core particle, the shell comprising a polymer having a monomer unit represented by the following formula (I), the toner comprising a specific external additive A, the external additive A being at least one selected from the group consisting of silica fine particles and organosilicon polymer fine particles, and the coverage rate of the external additive A on the surface of the toner particles being 0.3 area % or more: #imgabs0# In formula (I), L 1 Represents ‑COO(CH2) n ‑(wherein n is an integer from 1 to 10), and L 1 The carbonyl group is bonded to the carbon atom of the main chain; R 1 represents hydrogen or methyl; and R 2 to R 10 Each independently represents an alkyl group having 1 to 4 carbon atoms.

Description

Technical Field

[0001] The present disclosure relates to a toner used in a recording method based on, for example, electrophotography. Background Art

[0002] In recent years, with the further development of computers and multimedia, user demands for image forming devices such as copiers and printers have continued to evolve. Furthermore, there is a growing demand for higher performance in terms of longer life, smaller size, and higher speed. For example, in office applications involving high-volume printing, consistent output image quality is required regardless of the number of images output. To meet these demands, further improvements in toner performance and durability are necessary.

[0003] In Japanese Patent Application Laid-Open No. 2017-032598, an external additive having a large particle size is used as a technology for improving the durability of toner.

[0004] Furthermore, Japanese Patent Application Laid-Open No. 2014-130238 discloses a toner having a surface layer containing a silicone polymer as a toner having excellent storage stability, environmental stability, and development durability.

[0005] Japanese Patent Application Publication No. 2017-134367 discloses a method for producing a toner whose surface is covered with two or more silicon compounds. Summary of the Invention

[0006] However, when improving durability by adding a large amount of a large-particle external additive, as in Japanese Patent Application Publication No. 2017-032598, it is considered difficult to fix the large-particle external additive to the toner particle surface due to the weak physical / electrostatic force on the toner particle surface due to the size of the large-particle external additive. Unfixed large-particle external additives cause member contamination on the charging member and the photosensitive drum, which can result in image defects (vertical streaks in a solid image).

[0007] While methods such as the method disclosed in Japanese Patent Application Publication No. 2014-130238 are effective measures for the phenomenon of toner release agents or resin components seeping out from the interior of the toner onto the surface (bleeding), when using external additives, it is necessary to improve contamination of components caused by long-term use. Toners produced according to methods such as the method disclosed in Japanese Patent Application Publication No. 2017-134367 exhibit excellent charge stability even under high-temperature and high-humidity environments, but when using external additives, it is necessary to improve contamination of components caused by long-term use.

[0008] An object of the present disclosure is to provide a toner that, while satisfying low-temperature fixability, shows improved image streaks and member contamination even after long-term use, and in which migration of external additives to members is also suppressed.

[0009] The present disclosure relates to a toner comprising toner particles, wherein

[0010] The toner particles have a core-shell structure including a core particle and a shell on the surface of the core particle,

[0011] The shell includes a polymer having a monomer unit represented by the following formula (I),

[0012] The toner includes an external additive A having a particle size of 30 nm to 300 nm,

[0013] The external additive A is at least one selected from the group consisting of silica fine particles and organosilicon polymer fine particles, and

[0014] The coverage ratio of the external additive A on the surface of the toner particles is 0.3 area % or more:

[0015]

[0016] In formula (I), L 1 Represents -COO(CH2) n - (wherein n is an integer from 1 to 10), and L 1 The carbonyl group is bonded to the carbon atom of the main chain; R 1 represents hydrogen or methyl; and R 2 to R 10 Each independently represents an alkyl group having 1 to 4 carbon atoms.

[0017] The present disclosure can provide a toner that exhibits improved image streaks and member contamination even after long-term use while satisfying low-temperature fixability, and in which migration of external additives to members is also suppressed. Further features of the present invention will become apparent from the following description of exemplary embodiments. DETAILED DESCRIPTION

[0018] In the present disclosure, unless otherwise specified, the symbols "from XX to YY" and "XX to YY" indicating a numerical range indicate a numerical range including the lower limit and the upper limit of the range as endpoints. In the case of describing a numerical range in sections, the upper and lower limits of each numerical range can be arbitrarily combined. In addition, the term monomer unit refers to the reacted form of a monomer substance in a polymer.

[0019] The present disclosure relates to a toner comprising toner particles, wherein

[0020] The toner particles have a core-shell structure including a core particle and a shell on the surface of the core particle,

[0021] The shell includes a polymer having a monomer unit represented by the following formula (I),

[0022] The toner includes an external additive A having a particle size of 30 nm to 300 nm,

[0023] The external additive A is at least one selected from the group consisting of silica fine particles and organosilicon polymer fine particles, and

[0024] The coverage of the toner particle surface by the external additive A is 0.3 area % or more:

[0025]

[0026] In formula (I), L 1 Represents -COO(CH2) n - (wherein n is an integer from 1 to 10), and L 1 The carbonyl group is bonded to the carbon atom of the main chain; R 1 represents hydrogen or methyl; and R 2 to R 10 Each independently represents an alkyl group having 1 to 4 carbon atoms.

[0027] The present inventors have discovered that, thanks to the aforementioned toner, it is possible to provide a toner in which migration of external additives to components is suppressed even over long periods of time, while also improving image streaks and component contamination. The present inventors speculate as follows regarding the underlying reasons for this. The present inventors speculate that migration of external additives to components can be suppressed by increasing the affinity between the toner particle surface and the external additives, and further increasing the contact frequency and area between the two.

[0028] In the case of the above-mentioned structure, the siloxane structure is present in the monomer unit represented by formula (I) and is included in the polymer contained in the shell of the toner particle. Therefore, the affinity between the monomer unit represented by formula (I) and the external additive having a siloxane bond is high, and the toner particles and the external additive are easily adhered to each other.

[0029] In addition, the monomer unit represented by formula (I) has a flexible molecular structure and contains an alkylene group and a trimethylsilyl group that do not undergo a condensation reaction. As a result, the contact area between the siloxane structure in the monomer unit represented by formula (I) and the external additive increases, which can inhibit the migration of the external additive to the component.

[0030] Furthermore, the C=O and Si-O sites of the monomer unit represented by formula (I) are linked via an alkylene group having 1 to 10 carbon atoms. In this structure, the polarized C=O and Si-O sites are within the aforementioned range of electrostatic interaction, allowing charge transfer between them. As a result, the electrostatic attraction between the toner particles and the external additive becomes stronger, and the external additive can be suppressed from detaching from the toner particle surface. This suppresses image streaks even after prolonged use.

[0031] Furthermore, the monomer unit represented by formula (I) contains a trimethylsilyl group and has a structure in which a condensation reaction between monomer units does not occur; as a result, it is considered that the shell is less likely to harden and the low-temperature fixability is less likely to be hindered.

[0032] The toner includes an external additive A having a large particle size of 30nm to 300nm. The coverage of the surface of the toner particles by the external additive A is controlled to be 0.3 area % or more. As a result, sufficient fluidity can be imparted to the toner. The coverage of the surface of the toner particles by the external additive A (hereinafter also referred to as coverage ratio) is preferably 20.0 area % or less, and more preferably 1.5 area % to 10.0 area %. Because the amount of the external additive A that is not fixed to the toner particles is reduced when the coverage ratio is 20.0 area % or less, it becomes possible to suppress the occurrence of adverse effects such as initial image streaks and image fogging. The coverage of the surface of the toner particles by the external additive A can be controlled based on the particle size and addition amount of the external additive A.

[0033] The external additive A is a particle having a particle size of 30 nm to 300 nm. When the particle size is 30 nm or greater, electrostatic aggregation of the external additive is less likely to occur, and adverse image effects resulting from poor regulation can be avoided. If the external additive on the toner surface becomes electrostatically aggregated, the external additive coverage decreases and the toner's fluidity decreases, resulting in adverse image effects resulting from poor regulation. Poor regulation is a phenomenon in which the toner load on the developer roller cannot be adequately regulated by the toner regulating member, and the unsuccessfully regulated toner coating becomes uneven on the developer roller, which can lead to adverse image effects in the form of image unevenness.

[0034] When the particle size of the external additive A is greater than 300 nm, the external additive A is less likely to stably stay on the toner particle surface and may cause member contamination. Preferably, the number average particle size of particles identified as the external additive A is calculated to be 50 nm to 200 nm.

[0035] The characteristics of the toner are described in detail below, but the present invention is not limited to these characteristics.

[0036] shell

[0037] The toner particles have a core-shell structure comprising a core particle and a shell on the surface of the core particle. The shell does not necessarily cover the entire core particle, and a portion of the core particle may be left exposed. The shell has a polymer comprising a monomer unit represented by formula (I). Preferably, the shell is made of a polymer comprising a monomer unit represented by formula (I). The content ratio of the polymer comprising the monomer unit represented by formula (I) in the shell is preferably 50% by mass to 100% by mass, more preferably 75% by mass to 100% by mass, and even more preferably 90% by mass to 100% by mass.

[0038] In formula (I), L 1 Represents -COO(CH2) n - (wherein n is an integer from 1 to 10), and L 1 The carbonyl group in is bound to the carbon atom of the main chain. 1 represents hydrogen or methyl. 2 to R 10 Each independently represents an alkyl group having 1 to 4 (preferably 1 to 3, more preferably 1 to 2, and still more preferably 1) carbon atoms. In the case where the polymer comprises a plurality of different monomer units of formula (I), n, R 1 and R 2 to R 10 Can be the same or can be different.

[0039] Furthermore, n in formula (I) is preferably 1 to 8, more preferably 1 to 5, and still more preferably 1 to 3. When n is 1 to 5, the distance between the polarized C═O site and the Si—O site in formula (I) decreases, and as a result, charge transfer easily occurs.

[0040] The polymer contained in the shell may be made solely from the monomer unit represented by formula (I), or may be a copolymer of the monomer unit represented by formula (I) and one or more other monomer units. The polymerizable monomer used for copolymerization can be appropriately set according to the toner particles to be produced; for example, vinyl polymerizable monomers that can be used for free radical polymerization can be used herein. Monofunctional polymerizable monomers or polyfunctional polymerizable monomers can be used as the vinyl polymerizable monomer.

[0041] Examples of the monofunctional polymerizable monomer include the following.

[0042] Styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-butylstyrene, p-tert-butylstyrene, p-hexylstyrene, p-octylstyrene, p-nonylstyrene, p-decylstyrene, p-dodecylstyrene, p-methoxystyrene and p-phenylstyrene; styrene derivatives such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate, ethyl acrylate, diethyl phosphate, dibutyl phosphate, ethyl acrylate and 2-phenyl acrylate Acrylic polymerizable monomers such as formyloxyethyl ester; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate, ethyl methacrylate and dibutyl phosphate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

[0043] Examples of the polyfunctional polymerizable monomer include the following.

[0044] For example, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis(4-(acryloyloxydiethoxy)phenyl)propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate acrylates, polyethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis(4-(methacryloyloxydiethoxy)phenyl)propane, 2,2'-bis(4-(methacryloyloxypolyethoxy)phenyl)propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.

[0045] The content ratio of the monomer unit represented by formula (I) in the polymer having the monomer unit represented by formula (I) is preferably 50% by mass or more. When the content ratio of the monomer unit represented by formula (I) is 50% by mass or more, the proportion of the monomer unit present at the contact interface between the toner particles and the external additive A increases, and the contact area with the external additive A similarly increases, thereby easily obtaining the effect derived from the above-mentioned mechanism. This content ratio is more preferably 70% by mass to 100% by mass, and even more preferably 90% by mass to 100% by mass.

[0046] Preferably, in a backscattered electron image of the toner particles taken at a magnification of 10,000 times using a scanning electron microscope, the shell coverage of the core particle surface is 80 area % or more. When the shell coverage of the core particle surface is 80 area % or more, the proportion of the shell present on the surface of the core particle is high, and the probability of contact with the external additive A is increased, thereby easily obtaining the effect derived from the above-mentioned mechanism. The method for calculating the shell coverage of the core particle surface will be described later. The coverage is more preferably 85 area % or more, and even more preferably 90 area % or more. There is no particular upper limit, but it is preferably 100 area % or less, and more preferably 97 area % or less. The coverage can be controlled based on the particle size and addition amount of the external additive A.

[0047] The content of the shell is preferably 0.10 to 4.00 parts by mass, more preferably 0.30 to 2.00 parts by mass relative to 100 parts by mass of the core particles. When the content is 0.10 parts by mass or more, the amount of the monomer unit represented by formula (I) contained in the shell is appropriate, thereby making it easier to achieve the above-mentioned effects. When the content is 4.00 parts by mass or less, it is less likely to hinder fixing.

[0048] In the toner, a polymer comprising a monomer unit represented by formula (I) is included in a shell contained in the toner particles. This can be achieved by 1 The shell structure was confirmed by H-NMR analysis. The detailed steps will be described later.

[0049] External Additive A

[0050] Next, the external additive A will be described. The external additive A is a particle having a particle size of 30 nm to 300 nm. The external additive A is at least one selected from the group consisting of fine silica particles and fine organosilicon polymer particles. The external additive A preferably includes fine silica particles. Preferably, the external additive A includes fine silica particles and fine organosilicon polymer particles. The particle shape is preferably spherical, and the major diameter / minor diameter ratio is preferably 1.3 or less.

[0051] There are no particular limitations on the external additive A, provided that the above conditions are met. Examples of the particles of the external additive A that can be used include sol-gel silica fine particles, fumed silica fine particles, and organosilicon polymer fine particles, as well as combinations thereof. These particles may be surface-treated with, for example, a silane coupling agent, a titanium coupling agent, or silicone oil.

[0052] Specific examples of the organosilicon polymer fine particles include fine particles of an organosilicon polymer having a siloxane bond as a main chain. The organosilicon polymer is formed by at least one selected from the group consisting of structural units represented by the following formulae (1) to (4). In the formula, R 11 to R 16 Each is, for example, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.

[0053]

[0054] When the organosilicon polymer includes a large amount of the structure of formula (3) (hereinafter also referred to as "T3 unit structure"), the organosilicon polymer, while being used as an external additive, can achieve a well-balanced elasticity that effectively disperses the pressure by appropriately deforming even when the organosilicon polymer is subjected to embedding pressure. In other words, particles are obtained that are not easily embedded in toner particles but are simultaneously imparted with fluidity.

[0055] Specifically, in 29 In Si-NMR measurement, the ratio of the surface area of ​​the peak derived from silicon having a T3 unit structure to the total surface area of ​​the peak derived from all silicon contained in the organic silicon polymer fine particles is preferably 0.70 to 1.00. More preferably, the ratio is 0.90 to 1.00. 16 There is no special restriction, but in R 16 In the case of an alkyl group having 1 to 6 (preferably 1 or 2, more preferably 1) carbon atoms or a phenyl group, migration of the organosilicon polymer fine particles from the toner particles can be suitably suppressed.

[0056] The production method of the organosilicon polymer fine particles is not particularly limited and may involve, for example, dropwise addition of a silane compound, followed by hydrolysis using a catalyst and condensation reaction, followed by filtration and drying of the resulting suspension. The particle size can be controlled, for example, based on the type of catalyst, the mixing ratio, the reaction start temperature, and the dropwise addition time.

[0057] Examples of the catalyst include, but are not limited to, 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.

[0058] Next, the organosilicon compound used for producing the organosilicon polymer fine particles will be explained.

[0059] The organosilicon polymer is preferably a condensate of an organosilicon compound having a structure represented by the following formula (Z).

[0060]

[0061] In formula (Z), R a represents an organic functional group; and R 1 、R 2 , and R 3 Each independently represents a halogen atom, a hydroxyl group, an acetoxy group or an alkoxy group (preferably having 1 to 3 carbon atoms).

[0062] In addition, R a The organic functional group is not particularly limited, but is preferably exemplified by a hydrocarbon group (preferably an alkyl group) having 1 to 6 (preferably 1 to 3, and more preferably 1 or 2) carbon atoms, or an aryl group (preferably a phenyl group).

[0063] In addition, R 1 、R 2 , and R 3 Each is independently a halogen atom, a hydroxyl group, an acetoxy group or an alkoxy group. The foregoing is a reactive group and forms a cross-linked structure by hydrolysis, addition polymerization, and condensation. 1 、R 2 , and R 3 The hydrolysis, addition polymerization, and condensation of can be controlled based on the reaction temperature, reaction time, reaction solvent and pH. a In addition to the three reactive groups (R 1 、R 2 and R 3 ) are also called trifunctional silanes.

[0064] Examples of formula (Z) include the following.

[0065] For example, trifunctional methylsilanes such as p-styryltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxychlorosilane, methylmethoxyethoxychlorosilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydiethoxysilane, methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane and methyldiethoxyhydroxysilane; Examples include trifunctional ethylsilanes such as ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, and ethyltrihydroxysilane; trifunctional propylsilanes such as propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, and propyltrihydroxysilane; trifunctional butylsilanes such as butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, and butyltrihydroxysilane; trifunctional hexylsilanes such as hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, and hexyltrihydroxysilane; and trifunctional phenylsilanes such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, and phenyltrihydroxysilane. The organosilicon compound may be used alone or in combination of two or more.

[0066] In addition, the following can be used in combination with the organosilicon compound having a structure represented by formula (Z). Organosilicon compounds having four reactive groups in one molecule (tetrafunctional silane), organosilicon compounds having two reactive groups in one molecule (difunctional silane), organosilicon compounds having one reactive group (monofunctional silane). For example, the following are examples.

[0067] For example, trifunctional vinyl silanes such as dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, vinyltriisocyanate silane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane and vinyldiethoxyhydroxysilane.

[0068] The content of the structure represented by formula (Z) in the monomer forming the silicone polymer is preferably 50 mol % or more, and more preferably 60 mol % or more.

[0069] As the case requires, fine particles other than the external additive A may be used in combination in the toner as an external additive, provided that the above-mentioned effects are not impaired. This can control, for example, fluidity, chargeability, and cleaning properties.

[0070] Examples of external additives include silica fine particles and other inorganic oxide fine particles made of aluminum oxide fine particles or titanium oxide fine particles, inorganic stearic acid compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, and inorganic titanate compound fine particles such as strontium titanate and zinc titanate.

[0071] The silica fine particles include, for example, dry-process silica fine particles produced by vapor-phase oxidation of silicon halide, so-called dry silica fine particles or fumed silica, and so-called wet silica fine particles produced from water glass or the like.

[0072] As dry silica fine particles, composite fine particles of silica and other metal oxides can be obtained by using other metal halide compounds such as aluminum chloride or titanium chloride together with silicon halide in the production process.

[0073] Preferably, these inorganic fine particles are surface-treated with, for example, a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil, a silicone varnish, or various modified silicone varnishes. The surface treatment agent can be used alone or in combination of two or more. This can adjust the charge of the toner, improve heat resistance and storage properties, and improve environmental stability.

[0074] The content ratio of the external additive A is preferably 0.1 to 6.0 parts by mass, more preferably 0.5 to 2.5 parts by mass, and still more preferably 1.5 to 2.2 parts by mass relative to 100 parts by mass of the toner particles.

[0075] Binder resin

[0076] The core particles may include a binder resin. The binder resin is not particularly limited, and known binder resins may be used herein. For example, homopolymers of styrene and its substituted products such as styrene and vinyltoluene; for example, styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-butyl acrylate copolymers, styrene-octyl acrylate copolymers, styrene-dimethylaminoethyl acrylate copolymers, styrene-methyl methacrylate copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-dimethylaminoethyl methacrylate copolymers, styrene-vinyl methyl ether copolymers, styrene-vinyl ethyl ether copolymers, styrene Copolymers of aromatic vinyl compounds such as ethylene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers; homopolymers of aliphatic vinyl compounds such as ethylene and propylene and their substituted products; vinyl resins such as polyvinyl acetate, polyvinyl propionate, polyvinyl benzoate, polyvinyl butyrate, polyvinyl formate, and polyvinyl butyral; vinyl ether resins; vinyl ketone resins; acrylic polymers; methacrylic polymers; silicone resins; polyester resins; polyamide resins; epoxy resins; phenolic resins; and rosin, modified rosin, and terpene resins. The foregoing may be used alone or in combination of two or more.

[0077] As the copolymer of the aromatic vinyl compound, for example, the following vinyl copolymers such as an aromatic vinyl compound, an acrylic polymerizable monomer, and a methacrylic polymerizable monomer can be used.

[0078] Examples of the aromatic vinyl compound and its substitution product include the following.

[0079] Examples include styrene and styrene derivatives such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene and p-phenylstyrene.

[0080] As the polymerizable monomer forming the acrylic polymer, examples of the acrylic polymerizable monomer include, for example, acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, and n-pentyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate and 2-benzoyloxyethyl acrylate.

[0081] Examples of the methacrylic acid polymerizable monomer forming the methacrylic acid polymer include, for example, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate, ethyl methacrylate, and dibutyl phosphate, ethyl methacrylate.

[0082] The polycondensates of the carboxylic acid components and alcohol components listed below can be used as polyester resins. Examples of the carboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid. Examples of the alcohol components include bisphenol A, hydrogenated bisphenol, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, glycerol, trimethylolpropane, and pentaerythritol.

[0083] The polyester resin may be a polyester resin containing a urea group. Carboxyl groups in the polyester resin, such as those at the terminals, are preferably uncapped.

[0084] For the purpose of improving the viscosity change of the toner at high temperature, the binder resin may have a polymerizable functional group. Examples of the polymerizable functional group include a vinyl group, an isocyanate group, an epoxy group, an amino group, a carboxyl group, and a hydroxyl group.

[0085] The binder resin is preferably a vinyl resin or a polyester resin, more preferably a vinyl resin. When the binder resin is a vinyl resin, copolymerization can be initiated between the core and shell of the core-shell structure, and adverse effects such as cracking or peeling of the toner due to long-term durability can be prevented.

[0086] Among the foregoing, the binder resin is more preferably a styrene (meth) acrylic acid copolymer represented by, for example, styrene-butyl acrylate, styrene-alkyl (meth) acrylate copolymers, etc. The production method of the polymer is not particularly limited, and a known method can be employed herein.

[0087] wax

[0088] The toner particles may include wax. Known waxes may be used as the wax without particular limitation. Examples of waxes include the following. Aliphatic hydrocarbon waxes and derivatives thereof, such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, Fischer-Tropsch wax and paraffin wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax or its block copolymers; waxes having fatty acid esters as main components such as carnauba wax and montanate wax; partially or fully deoxygenated fatty acid esters such as deoxycarnauba wax; saturated branched fatty acids such as palmitic acid, stearic acid and montanic acid; unsaturated fatty acids such as brassene acid, eleostearic acid and octadecatetraenoic acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, tetracosyl alcohol, serinol and melislol; polyols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide and lauryl amide; fatty acid amides such as methylene bis(stearamide), ethylene bis(octadecatetraenoic acid) Saturated fatty acid bisamides such as ethylenebis(capramide), ethylenebis(lauramide), and hexamethylenebis(stearamide); unsaturated fatty acid amides such as ethylenebis(oleamide), hexamethylenebis(oleamide), N,N'-dioleyl adipamide, and N,N'-dioleyl sebacamide; aromatic bisamides such as m-xylene bis(stearamide) and N,N'-distearylisophthalamide; fatty metal salts (commonly known as metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate; aliphatic hydrocarbon waxes grafted with vinyl monomers such as styrene and acrylic acid; partial esterification products of fatty acids and polyols such as monoglyceride of behenic acid; and methyl ester compounds having hydroxyl groups and obtained by hydrogenation of vegetable oils and fats, for example. The above waxes can be used alone or in combination of two or more.

[0089] Examples of the aliphatic alcohols forming the ester wax include 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, undecanol, lauryl alcohol, myristyl alcohol, 1-hexadecanol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, and lignocerol. Examples of the aliphatic carboxylic acids include valeric acid, hexanoic acid, heptanoic acid, octanoic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidonic acid, behenic acid, and lignoceric acid.

[0090] The content of the wax is preferably 0.5 parts by mass to 30.0 parts by mass relative to 100.0 parts by mass of the binder resin or the polymerizable monomer.

[0091] Colorants

[0092] The toner particles may include a colorant. The colorant is not particularly limited, and for example, the following known colorants may be used.

[0093] Examples of yellow pigments include iron oxide yellow, Naples Yellow, Naphthol Yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, condensed azo compounds such as tartrate lake, and isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples include CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, and 180.

[0094] Examples of the orange pigment include Permanent Orange GTR, Pyrazolone Orange, Balkan Orange, Benzidine Orange G, Indanthrene Brilliant Orange RK, and Indanthrene Brilliant Orange GK.

[0095] Examples of red pigments include red iron oxide, Permanent Red 4R, Lithol Red, pyrazolone red, view red calcium salt, Lake Red C, Lake Red D, Brilliant Carmine 6B, Brilliant Carmine 3B, Eosin Lake, Rhodamine Lake B, condensed azo compounds such as Rubiacin Lake, and diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

[0096] Specific examples include CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254, and 269.

[0097] Examples of blue pigments include basic blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, ketone phthalocyanine pigments such as Fast Sky Blue and Indigo BG and their derivatives, anthraquinone compounds, and basic dye lake compounds. Specific examples include CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

[0098] Examples of violet pigments include Fast Violet B and Methyl Violet Lake. Examples of green pigments include Pigment Green B, Malachite Green Lake, and Ultimate Yellow Green G.

[0099] Examples of white pigments include zinc oxide, titanium oxide, antimony white, and zinc sulfide.

[0100] Examples of black pigments include carbon black, aniline black, non-magnetic ferrite, magnetite, and colorants that are matched to black using the above-mentioned yellow colorant, red colorant, and blue colorant. These colorants can be used alone or in a mixture, and can also be used in the state of a solid solution.

[0101] The colorant may be surface-treated with a substance that does not hinder polymerization, as occasion demands.

[0102] The content of the colorant is preferably 1.0 to 15.0 parts by mass relative to 100.0 parts by mass of the binder resin or the polymerizable monomer.

[0103] Charge control agent

[0104] The toner particles may contain a charge control agent. Known agents can be used as the charge control agent, but preferred herein are those that exhibit a high triboelectric charging rate and can stably maintain a constant triboelectric charge amount. When producing toner particles by a polymerization method, preferred charge control agents have low polymerization inhibition properties and are substantially insoluble in aqueous media.

[0105] The charge control agent may be a charge control agent that controls the toner so as to exhibit negative chargeability or positive chargeability.

[0106] Examples of charge control agents that control the colorant so as to exhibit negative chargeability include the following: monoazo metal compounds, acetylacetonate metal compounds, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, metal compounds of hydroxycarboxylic acids and dicarboxylic acids; aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids and polycarboxylic acids and their metal salts, anhydrides and esters; phenol derivatives such as bisphenol; and urea derivatives, metal-containing salicylic acid compounds, metal-containing benzoic acid compounds, boron compounds, calixarenes, and resin-based charge control agents.

[0107] Examples of the charge control agent that controls the toner so as to exhibit positive chargeability include the following.

[0108] Aniline black and its modified products with fatty acid metal salts; guanidine compounds; imidazole compounds; onium salts such as quaternary ammonium salts such as tributylbenzylammonium 1-hydroxy-4-naphthalenesulfonate and tetrabutylammonium tetrafluoroborate and the like, phosphonium salts as the aforementioned analogs, and the aforementioned lake pigments; and triphenylmethane dyes and lake pigments (examples of lake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide compounds and ferrocyanide compounds); and metal salts of higher fatty acids, and resin-based charge control agents.

[0109] The charge control agent may be used alone or in combination of two or more. Among these charge control agents, metal-containing salicylic acid compounds are preferred, particularly compounds in which the metal is aluminum or zirconium.

[0110] The amount of the charge control agent added is preferably 0.1 parts by mass to 20.0 parts by mass, more preferably 0.5 parts by mass to 10.0 parts by mass, relative to 100.0 parts by mass of the binder resin.

[0111] As the charge control resin, a polymer or copolymer containing a sulfonic acid group, a sulfonate group, or a sulfonate ester group is preferably used. Preferably, the polymer containing a sulfonic acid group, a sulfonate group, or a sulfonate ester group contains 2% by mass or more of a sulfonic acid group-containing acrylamide monomer or a sulfonic acid group-containing methacrylamide monomer, based on the copolymerization ratio. More preferably, this content is 5% by mass or more, based on the copolymerization ratio.

[0112] Preferably, the charge control resin has a glass transition temperature (Tg) of 35° C. to 90° C., a peak molecular weight (Mp) of 10,000 to 30,000, and a weight average molecular weight (Mw) of 25,000 to 50,000.

[0113] When such a charge control resin is used, it is possible to impart preferred triboelectric charging characteristics without affecting the thermal properties required of toner particles. The charge control resin contains a sulfonic acid group, and thus can improve both the dispersibility of the charge control resin itself in the colorant dispersion and the dispersibility of the colorant itself; furthermore, it can also improve tinting strength, transparency, and triboelectric charging characteristics.

[0114] Next, a method of obtaining the toner will be described in detail.

[0115] Shell formation method

[0116] The toner particles have a shell. The shell includes a polymer having a monomer unit represented by formula (I). The method for obtaining the polymer having the monomer unit represented by formula (I) is not particularly limited, and known methods can be used herein. Examples include the following methods. A method for polymerizing a polymerizable monomer in the form of a monomer unit represented by formula (I) after reaction. Specific examples include the following polymerizable monomers.

[0117] For example, 3-(methacryloyloxy)propyltris(trimethylsilyloxy)silane, 3-(acryloyloxy)propyltris(trimethylsilyloxy)silane, 3-(methacryloyloxy)propyltris(trimethylsilyloxy)silane, 3-(methacryloyloxy)propyltris(triethylsiloxy)silane, 3-(methacryloyloxy)hexyltris(trimethylsiloxy)silane and 3-(methacryloyloxy)octyltris(trimethylsiloxy)silane.

[0118] The above-mentioned polymerizable monomers can also be obtained by synthesis. There is no particular limitation on the synthesis method, and known methods can be used herein. For example, the polymerizable monomers can be obtained by the reaction between the following trifunctional silanes and monofunctional silanes. The trifunctional silane is a compound represented by formula (II).

[0119]

[0120] In formula (II), L 2 Represents -COO(CH2) n -(wherein n is an integer from 1 to 10). In addition, R 17 represents hydrogen or methyl. a 、R b and R c Each is independently a halogen atom, a hydroxyl group or an alkoxy group (preferably having 1 to 3 carbon atoms).

[0121] Specific examples include the following. For example, 3-methacryloxymethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, 3-methacryloxypropylethoxydimethoxysilane, 3-methacryloxypropyltriethoxysilane, acryloxypropyltriethoxysilane, 3-methacryloxypropyltrichlorosilane, 3-methacryloxypropylmethoxydichlorosilane, 3-methacryloxypropyldimethoxychlorosilane, 3-methacryloxymethyltrihydroxysilane, 3-methacryloxypropyltrihydroxysilane, acryloxypropyltrihydroxysilane, and 3-methacryloxypropylethoxydihydroxysilane.

[0122] The monofunctional silane is a compound represented by formula (III).

[0123]

[0124] Where R d 、R e and R f each independently represents an alkyl group having 1 to 4 (preferably 1 to 3, more preferably 1 to 2, and still more preferably 1) carbon atoms, and R g is a halogen atom, a hydroxyl group or an alkoxy group (preferably having 1 to 3 carbon atoms).

[0125] Specific examples include the following: trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, tripropylethoxysilane, chlorotrimethylsilane, chlorotriethylsilane, and chlorotripropylsilane.

[0126] The halogen atoms, hydroxyl groups, or alkoxy groups (hereinafter, also referred to as reactive groups) of the trifunctional silane are each independently hydrolyzed / condensed with the halogen atoms, hydroxyl groups, or alkoxy groups (hereinafter, also referred to as reactive groups) of the monofunctional silane. As a result, a polymerizable monomer forming a monomer unit represented by formula (I) can be obtained.

[0127] There is no particular limitation on the formation method of the shell of the polymer having the monomeric unit represented by formula (I), and known methods can be used. Example includes the polymerization of the polymerizable monomer forming the shell in the aqueous medium in which the core particles are dispersed, to form a shell on the core particles. Further examples include the polymerization of the polymerizable monomer forming the shell during the production process of the core particles described later, and the polymerization of the monomer to form a shell, and the polymerization of the polymerizable monomer forming the shell, and the polymerization of the polymer obtained during the production process of the core particles described later, to form a shell.

[0128] Preferred among the foregoing are methods of polymerizing a polymerizable monomer for shell formation in an aqueous medium in which core particles are dispersed to form a shell on the core particles, because such methods allow the coverage of the shell to be improved.

[0129] The method for forming a shell will be described in more detail below. In order to form a shell on the core particle, the method preferably includes dispersing the core particle in an aqueous medium to obtain a core particle dispersion (step 1), and forming a shell comprising a polymer comprising monomeric units represented by formula (I) (step 2).

[0130] The method for obtaining the core particle dispersion in step 1 includes a method involving using the dispersion of the produced core particles in an aqueous medium as is, and a method involving adding the dried core particles to an aqueous medium and mechanically dispersing the entirety. A dispersion aid may be used to disperse the dried core particles in an aqueous medium.

[0131] Known dispersion stabilizers and surfactants can be used as dispersing aids. Specific examples of dispersion stabilizers include inorganic dispersion stabilizers such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silicon dioxide, and aluminum oxide; and organic dispersion stabilizers such as polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropyl cellulose, ethylcellulose, sodium carboxymethyl cellulose, and starch. Examples of surfactants include anionic surfactants such as alkyl sulfates, alkylbenzene sulfonates, and fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxypropylene alkyl ethers; and cationic surfactants such as alkylamine salts and quaternary ammonium salts. Among the aforementioned, the dispersion preferably includes an inorganic dispersion stabilizer, more preferably a dispersion stabilizer including phosphates such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, and aluminum phosphate.

[0132] In step 2, the polymerizable monomer for forming the shell can be added as is to the core particle dispersion; alternatively, a dispersion obtained by dispersing the polymerizable monomer in ion-exchanged water can be added to the core particle dispersion. Of the aforementioned, adding a dispersion obtained by dispersing the polymerizable monomer in ion-exchanged water is preferred because, in this case, the shell can be easily and uniformly formed. The dispersing machine used to disperse the polymerizable monomer in ion-exchanged water can be, for example, a homogenizer, a ball mill, a colloid mill, or an ultrasonic disperser.

[0133] The addition of the polymerization initiator can be completed at any time and at a desired time. Water-soluble initiators are generally used as polymerization initiators. Examples include the following: ammonium persulfate, potassium persulfate, 2,2'-azobis(N,N'-dimethyleneisobutyramidine) hydrochloride, 2,2'-azobis(2-aminobispropane) hydrochloride, azobis(isobutylamidine) hydrochloride, sodium 2,2'-azobisisobutyronitrile sulfonate, ferrous sulfate, and hydrogen peroxide.

[0134] These polymerization initiators can be used alone or in combination of two or more; and, for the purpose of controlling the degree of polymerization of the polymerizable monomer, a chain transfer agent or a polymerization inhibitor etc. can be further added and used. The weight average molecular weight (Mw) of the polymer can be adjusted based on the reaction temperature, reaction time, the amount of initiator and the amount of chain transfer agent. The weight average molecular weight (Mw) of the polymer in the shell is preferably 9000 to 120000, more preferably 11000 to 110000, and even more preferably 15000 to 100000.

[0135] Production of nuclear particles

[0136] The core particles can be produced using known production methods; dry methods such as kneading and pulverization methods, or wet methods such as suspension polymerization, dissolution suspension methods, emulsion aggregation methods, or emulsion polymerization aggregation methods can be employed. In particular, wet production methods are preferably used from the perspectives of narrowing the particle size distribution of the toner particles, improving the average circularity of the toner particles, and forming a core-shell structure. As an example, a method for obtaining core particles by suspension polymerization will be described below.

[0137] First, a polymerizable monomer capable of forming a binder resin and various additives are mixed as needed, and a polymerizable monomer composition dissolved or dispersed is prepared using a disperser. Examples of various additives include colorants, waxes, charge control agents, polymerization initiators, and chain transfer agents. Examples of dispersers include homogenizers, ball mills, colloid mills, and ultrasonic dispersers.

[0138] Next, the polymerizable monomer composition is put into an aqueous medium containing poorly water-soluble inorganic fine particles, and droplets of the polymerizable monomer composition are prepared using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser (granulation step).

[0139] Thereafter, the polymerizable monomer in the droplets is polymerized to obtain core particles (polymerization step).

[0140] The polymerization initiator may be mixed during the preparation of the monomer composition, or may be directly mixed into the polymerizable monomer composition before droplets are formed in an aqueous medium. In addition, the polymerization initiator may be added during droplet granulation or after granulation is completed, in a state where the polymerization initiator is dissolved in the polymerizable monomer or other solvent as needed, that is, it may be added directly before initiating the polymerization reaction. After the polymerizable monomer is polymerized to obtain the binder resin, a solvent removal process may be performed as needed to obtain a dispersion of core particles.

[0141] When the binder resin is obtained, for example, by emulsion aggregation or by suspension polymerization, conventionally known monomers can be used as polymerizable monomers without particular limitation. Specific examples include the vinyl monomers exemplified in the section of the binder resin.

[0142] As the polymerization initiator, a known polymerization initiator can be used without particular limitation. Specific examples include the following.

[0143] Peroxide-based polymerization initiators represented by hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralinapene hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, triphenyl acetate-tert-butyl hydroperoxide, tert-butyl performate, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, N-(3-toluoyl)peroxyacetate, Palmitate-tert-butyl benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, tert-butyl peroxyisobutyrate, tert-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide; and azo or disazo polymerization initiators such as 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-hydroxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile.

[0144] The production of the organosilicon polymer fine particles as the external additive A is as described above. Any method can be used to produce the silica fine particles, but the sol-gel method is preferred herein. The following describes a method for producing silica fine particles using the sol-gel method. First, an alkoxysilane is hydrolyzed and condensed in an organic solvent containing water using a catalyst to produce a silica sol suspension. The solvent is then removed from the silica sol suspension, and the suspension is dried to obtain the silica fine particles.

[0145] The major diameter of the fine silica particles obtained by the sol-gel method can be controlled based on the reaction temperature in the hydrolysis / condensation reaction step, the rate of addition of the alkoxysilane, the weight ratio of water, organic solvent, and catalyst, and the stirring speed. The fine silica particles thus obtained are generally hydrophilic and have many surface silanol groups. Therefore, when the fine silica particles are used as a toner external additive, it is preferred that the surface of the fine silica particles be hydrophobized.

[0146] The method for hydrophobization treatment may be a method involving removing the solvent from the silica sol suspension, drying, and then treating with a hydrophobization agent, or a method involving directly adding the hydrophobization agent to the silica sol suspension and treating while drying. From the viewpoint of controlling the half width of the particle size distribution and controlling the saturated water adsorption amount, the method involving directly adding the hydrophobization agent to the silica sol suspension is preferred.

[0147] Examples of hydrophobization methods include chemical treatment with an organosilicon compound that reacts with or physically adsorbs to silica. Preferred methods herein involve treating silica produced by vapor-phase oxidation of a halogenated silicon compound with an organosilicon compound. Examples of such organosilicon compounds include the following.

[0148] Hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, and benzyldimethylchlorosilane.

[0149] Further examples include bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, and triorganosilyl acrylate.

[0150] Further examples include vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldihydroxysilane, diphenyldiethoxysilane, and 1-hexamethyldisiloxane.

[0151] Still further examples include 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane having 2 to 12 siloxane units per molecule and one hydroxyl group at Si of the terminal unit.

[0152] The foregoing are used alone or as a mixture of two or more.

[0153] In the case of treatment with silicone oil, it is preferred to use a silicone oil having a viscosity of 30 mm at 25°C. 2 / s to 1000mm 2 Examples include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil.

[0154] Examples of silicone oil treatment methods include the following. A method involving directly mixing silica and silicone oil using a mixer such as an FM mixer. A method involving spraying silicone oil onto silica. Alternatively, a method involving dissolving or dispersing silicone oil in a suitable solvent, subsequently adding silica, mixing, and removing the solvent. After treatment with silicone oil, the silicone oil-treated silica is preferably heated to a temperature of 200° C. or higher (more preferably 250° C. or higher) in an inert gas to stabilize the surface coating.

[0155] The silica fine particles may be subjected to a deagglomeration treatment in order to facilitate achieving monodispersion of the silica fine particles on the surfaces of the toner particles and in order to exhibit a stable spacer effect.

[0156] developer

[0157] The toner may be used as a magnetic or non-magnetic one-component developer, but may be used as a two-component developer by being mixed with a carrier.

[0158] As the carrier, magnetic particles made of known materials such as metals such as iron, ferrite, or magnetite, and alloys of these metals with metals such as aluminum or lead can be used. Among the aforementioned, ferrite particles are preferably used. For example, a coated carrier in which the surface of the magnetic particles is coated with a coating agent such as a resin, or a resin-dispersed carrier obtained by dispersing magnetic fine powder in a binder resin can be used as the carrier.

[0159] The volume average particle diameter of the carrier is preferably 15 μm to 100 μm, more preferably 25 μm to 80 μm.

[0160] Next, a method of separating the toner particles from the toner will be described in detail. In order to analyze the shell contained in the toner particles, the following measurement is performed as follows using the toner particles separated from the toner.

[0161] Here, 160g sucrose (from Kishida Chemical Co. Ltd.) is added into 100mL ion exchange water and is dissolved in ion exchange water while heating in a hot water bath, to prepare a sucrose concentrate. Then, 31g of this sucrose concentrate and 6mL Contaminon N (made by nonionic surfactant, anionic surfactant and organic auxiliary agent, for washing the 10 mass % aqueous solution of pH 7 neutral detergent of precision measuring instrument, from Wako Pure Chemical Industries) are introduced into a centrifuge tube (capacity 50mL). Then, 1.0g toner is added into this dispersion liquid, and a spatula etc. is used to break up the toner block. Centrifuge tube was vibrated 20 minutes with 300spm (strokes per minute) in an oscillator (AS-1N, sold by AS ONE CORPORATION). After shaking, the solution was transferred to a glass tube (capacity 50 mL) for a swing rotor, and centrifuged at 3500 rpm for 30 minutes using a centrifuge (H-9R, from Kokusan Co. Ltd.).

[0162] As a result of this operation, the toner particles are separated from the external additive. Visually inspect the toner particles for sufficient separation from the aqueous solution, and collect the toner particles in the uppermost layer using a scraper or the like. The collected toner particles are filtered through a vacuum filter and then dried in a dryer for at least one hour to obtain a measurement sample. This operation is repeated multiple times to ensure the desired amount.

[0163] Next, a method for separating the polymer contained in the shell from the toner particles will be described in detail. To separate and analyze the shells contained in the toner particles, the polymer contained in the shells was separated from the toner particles as follows, and then the measurements described below were performed. The polymer contained in the shells of the toner particles was collected by separation using a solvent gradient elution using tetrahydrofuran (THF) to extract the extract. The preparation method is as follows.

[0164] Here, 10.0 g of toner particles were weighed, placed on cylindrical filter paper (No. 84, from Toyo Roshi Kaisha Ltd.), and placed in a Soxhlet extractor. Extraction was performed for 20 hours using 200 mL of THF as a solvent; the solid component obtained by removing the solvent from the extract was the THF-soluble fraction. The THF-soluble fraction includes a polymer having monomer units represented by formula (I). This was repeated multiple times to obtain the desired amount of THF-soluble fraction.

[0165] Gradient preparative HPLC (LC-20AP high pressure gradient preparative system from Shimadzu Corporation; SunFire preparative column) was used in the solvent gradient elution method. 250mm, from Waters Corporation). The column temperature was 30°C, the flow rate was 50mL / min, and acetonitrile was used as the weak solvent and THF was used as the strong solvent in the mobile phase. Here, the sample obtained by dissolving in 1.5mL THF was used, and 0.02g of the THF-soluble portion obtained by extraction was used as the separation sample. The mobile phase began with a composition of 100% acetonitrile, and 5 minutes after the sample was injected, the proportion of THF was increased by 4% per minute, so that the composition of the mobile phase reached 100% THF over the course of 25 minutes. The components can be separated by drying the obtained fractions.

[0166] Which component is the polymer containing the unit represented by formula (I) herein can be determined based on the following 1 The content of the shell of the toner particles can be determined based on the yield after the separation operation and based on the mass of the toner used for extraction.

[0167] The measurement methods of various physical properties will be described below.

[0168] Structural Analysis of the Polymer Contained in the Shell and Calculation Method of the Content Ratio of the Monomer Units Represented by Formula (I)

[0169] In the case where the obtained polymer contains a unit represented by structural formula (I), the unit may be based on 1 Identification by H-NMR measurement.

[0170] The specific measurement method is as follows.

[0171] Measuring device: FT NMR device JNM-EX400 (from JEOL Ltd.)

[0172] Measurement frequency: 400MHz

[0173] Pulse condition: 5.0μs

[0174] Frequency range: 10500Hz

[0175] Number of scans: 64 scans

[0176] Measurement temperature: 30℃

[0177] The measurement sample was prepared by placing 50 mg of the sample in a sample tube having an inner diameter of 5 mm, adding deuterated chloroform (CDCl3) as a solvent, and then dissolving in a constant temperature bath at 40°C. Then, the measurement was performed under the above conditions using the measurement sample. 2 to R 10The integrated value I(a) of the peak attributable to the alkyl group and the integrated value I(b) of the peak attributable to the methylene group in the polymer main chain were used to calculate the content ratio of the monomer unit according to the following expression.

[0178] I(a) / I(b)×100

[0179] Measurement of the surface coverage of the core particle by the shell

[0180] Use FE-SEMS-4800 (from Hitachi, Ltd.) to take the micrograph of multiple toner particles with 10,000 times magnification.In the image obtained by observation, the part of toner particle covered by shell is represented by high brightness, and core particle is represented by low brightness, therefore, the coverage of shell to toner particle surface can be quantified by binarization.Binarization condition can be appropriately selected based on observation device and based on sputtering condition.Herein, image processing software " ImageJ " is used for binarization, and background brightness distribution is removed by Subtract Background menu with flattening radius of 40 pixels, and then binarization is carried out with brightness threshold of 50.

[0181] One toner particle in the image is selected by image analysis using software. Next, the surface area of ​​the selected toner particle is obtained by performing image analysis. This surface area is represented by S(a). If a dark portion is observed in the toner particle whose surface area is to be measured, the dark portion is selected using software. Next, analysis is performed to thereby obtain the surface area of ​​the selected dark portion. In addition, S(b) represents the sum of the surface areas of the dark portions observed in the toner particles. The shell coverage is calculated based on the following formula.

[0182] Coverage (area %) = (S(a) - S(b)) / S(a) × 100

[0183] This measurement is performed on 100 toner particles, and the arithmetic mean of the measurements is taken as the coverage ratio of the shell to the surface of the core particle.

[0184] Measurement of particle size of external additive A

[0185] A micrograph of the toner surface was taken at a magnification of 30,000x using an FE-SEMS-4800 (manufactured by Hitachi, Ltd.). The major diameter of the external additive was measured using a magnified image of the micrograph; substances with a major diameter of 30 to 300 nm were designated as external additive A. To measure the number average particle size of external additive A, the major diameters of external additive A present on the surfaces of at least 100 toner particles were measured, and the resulting number average was taken as the number average particle size.

[0186] Similar measurements can be performed on toner particles containing multiple external additives on their surfaces. During observation of backscattered electron images using the S-4800, external additives of the same type can be distinguished by identifying the elements of each fine particle using elemental analysis such as EDAX. Furthermore, external additives of the same type can be selected based on, for example, their shape characteristics.

[0187] Coverage of the toner particle surface by the external additive A

[0188] The coverage of the toner particle surface by the external additive A was measured based on an observation image (30,000x magnification) in which the particle size of the external additive A was measured. The toner particle was positioned approximately at the center of the field of view, and the toner particle was depicted across the entire field of view. The following calculations were performed based on the observed image using the image processing software "ImageJ."

[0189] Only particles of External Additive A with a major diameter of 30 to 300 nm in the image were selected using the software's particle analysis. Next, the surface area selection screen appears based on the measurement settings. This surface area value is divided by the surface area of ​​the entire field of view to determine the coverage of External Additive A. This measurement is performed for 100 fields of view, and the arithmetic mean of the measurements is used as the coverage (area %) of External Additive A.

[0190] Measurement methods of weight average particle size and number average particle size

[0191] The weight average particle size and number average particle size of the toner, toner particles and core particles (hereinafter, also referred to as toner, etc.) are calculated as follows. The measuring device used here is a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, from Beckman Coulter, Inc.) based on the pore resistance method and equipped with a 100 μm orifice. The measurement conditions are set and the measurement data are analyzed using the dedicated software attached to the device (Beckman Coulter Multisizer 3, Version 3.51", from Beckman Coulter, Inc.). The measurement is performed in 25,000 effective measurement channels.

[0192] The aqueous electrolyte solution used in the measurement can be prepared by dissolving special grade sodium chloride in ion exchange water to a concentration of about 1.0 mass %; for example, “ISOTON II” (from Beckman Coulter, Inc.) can be used here as the aqueous electrolyte solution.

[0193] Before measurement and analysis, the dedicated software was set as follows.

[0194] In the "Change Standard Operation Mode (SOMME)" screen of the dedicated software, set the total count in the control mode to 50,000 particles, the number of measurements to one, and the Kd value to the value obtained using "Standard Particles 10.0 μm" (from Beckman Coulter). Press the "Threshold / Noise Level Measurement Button" to automatically set the threshold and noise level. Then, set the current to 1600 μA, the gain to 2, the electrolyte solution to ISOTON II, and check the "Rinse Orifice Tube After Measurement" checkbox.

[0195] In the "Pulse to Size Conversion Settings" screen of the dedicated software, the element spacing was set to logarithmic size, the size elements were set to 256 size elements, and the size range was set to the range of 2 μm to 60 μm.

[0196] The specific measurement method is as follows.

[0197] (1) Here, 200.0 mL of electrolyte aqueous solution was placed in the 250 mL round-bottom glass beaker included with the Multisizer 3. The beaker was set on the sample stage and stirred counterclockwise at 24 revolutions per second using a stirring rod. Dirt and bubbles were then removed from the nozzle using the "Nipple Rinse" function in the dedicated software.

[0198] (2) Then, approximately 30 mL of the electrolyte aqueous solution was placed in a 100 mL flat-bottom glass beaker. To this solution, approximately 0.3 mL of a three-fold dilution of "Contaminon N" (a 10% by mass aqueous solution of a pH 7 neutral detergent made of a nonionic surfactant, an anionic surfactant, and an organic builder, used for washing precision measuring instruments, available from Wako Pure Chemical Industries) was added as a dispersant.

[0199] (3) An ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (from Nikkaki Bios Co., Ltd.) with a power output of 120 W and equipped with two oscillators oscillating at a frequency of 50 kHz and configured with a phase shift of 180 degrees was prepared. 3.3 L of ion-exchanged water was added to the water tank of the ultrasonic disperser, and 2.0 mL of Contaminon N was added to the water tank.

[0200] (4) Place the beaker in (2) in the beaker fixing hole of the ultrasonic disperser, and then start the ultrasonic disperser. Adjust the height of the beaker to maximize the resonance state at the liquid surface of the electrolyte aqueous solution in the beaker.

[0201] (5) As the electrolyte aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, approximately 10 mg of the toner particles are then added little by little to the electrolyte aqueous solution to be dispersed therein. The ultrasonic dispersion treatment is further continued for 60 seconds. The water temperature of the water tank is appropriately adjusted to 10°C to 40°C during the ultrasonic dispersion.

[0202] (6) Using a pipette, the electrolyte aqueous solution in (5) containing, for example, the dispersed toner is added dropwise to the round-bottom beaker in (1) set inside the sample stage, and the measurement concentration is adjusted to approximately 5%. Measurement is then performed until the number of measured particles reaches 50,000.

[0203] (7) Analyze the measured data using the dedicated software included with the device to calculate the weight-average particle size and number-average particle size. When the dedicated software is set to Chart / Volume %, the weight-average particle size is obtained by looking at the "Average Diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" screen. When the dedicated software is set to Chart / Number %, the number-average particle size is obtained by looking at the "Average Diameter" on the "Analysis / Number Statistics (Arithmetic Mean)" screen.

[0204] Method for measuring number average molecular weight (Mn) and weight average molecular weight (Mw)

[0205] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the THF soluble portion of the polymer, resin, or toner particles are measured by gel permeation chromatography (GPC) as follows.

[0206] First, at room temperature over 24 hours, the sample was dissolved in tetrahydrofuran (THF). The obtained solution was then filtered through a solvent-resistant membrane filter "MYSYORI DISC" (from Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution was adjusted so that the concentration of the component soluble in THF was approximately 0.8% by mass. The sample solution was then used for measurement under the following conditions.

[0207] Apparatus: HLC8120 GPC (detector: RI) (from Tosoh Corporation)

[0208] Column: Shodex KF-801, 802, 803, 804, 805, 806, 807 7-column (from Showa Denko KK)

[0209] Eluent: tetrahydrofuran (THF)

[0210] Flow rate: 1.0 mL / min

[0211] Oven temperature: 40.0℃

[0212] Sample injection volume: 0.10mL

[0213] To calculate the molecular weight of the sample, a molecular weight calibration curve created using a standard 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 or A-500" from Tosoh Corporation) was used.

[0214] Example

[0215] The present invention will be described in more detail below with reference to the following examples. However, these examples are not intended to limit the present invention in any way. A toner and a method for producing the toner will be described below. Unless otherwise specified, all references to "parts" and "%" in the formulations of the Examples and Comparative Examples refer to parts by mass.

[0216] Production Example of Core Particle Dispersion

[0217] Core particle dispersion 1

[0218] Here, 11.2 parts of sodium phosphate (dodecahydrate) are put into the reaction vessel containing 390.0 parts of ion exchange waters, and when purging with nitrogen, the whole is incubated 1.0 hours at 65 DEG C. Use TK homomixer (from Tokushu Kika Kogyo Co., Ltd.) to stir with 12000rpm. While keeping stirring, the calcium chloride aqueous solution obtained by dissolving 7.4 parts of calcium chloride (dihydrate) in 10.0 parts of ion exchange waters is put into the reaction vessel once, to prepare the aqueous medium comprising dispersion stabilizer. Further, 1.0mol / L hydrochloric acid is added into the aqueous medium in the reaction vessel, so that pH is adjusted to 6.0 and to prepare aqueous medium 1.

[0219] Preparation of polymerizable monomer composition 1

[0220] - 60.0 parts of styrene

[0221] -CI Pigment Blue 15:3 6.3 parts

[0222] The above materials were put into an attritor (from Nippon Coke & Engineering Co., Ltd.), and further dispersed at 220 rpm for 5.0 hours using zirconium oxide particles having a diameter of 1.7 mm to prepare a colorant dispersion liquid 1 in which a pigment was dispersed.

[0223] Next, the following materials are added to the colorant dispersion liquid 1 .

[0224] - 10.0 parts of styrene

[0225] - 30.0 parts of n-butyl acrylate

[0226] - 5.0 parts of polyester resin

[0227] (Polycondensate of terephthalic acid and bisphenol A propylene oxide 2-mol adduct, weight average molecular weight Mw = 10000, acid value: 8.2 mgKOH / g)

[0228] - Hydrocarbon wax HNP9 (melting point: 76° C., produced by Nippon Seiro Co., Ltd.) 6.0 parts

[0229] The above materials were kept warm at 65° C. and uniformly dissolved and dispersed using a TK homomixer at 500 rpm to prepare a polymerizable monomer composition 1 .

[0230] Granulation step

[0231] While the temperature of the aqueous medium 1 was maintained at 70°C and the rotation speed of the stirrer was maintained at 12,500 rpm, the polymerizable monomer composition 1 was added to the aqueous medium 1, and 8.0 parts of t-butyl peroxypivalate as a polymerization initiator was further added. Granulation was performed for 10 minutes while the stirrer was maintained at 12,500 rpm.

[0232] Polymerization step

[0233] The agitator was changed from a high-speed agitator to an agitator equipped with a propeller stirring blade, and then polymerization was carried out by maintaining the temperature at 70°C and stirring at 200 rpm for 5.0 hours, further raising the temperature to 85°C and heating for 2.0 hours to carry out a polymerization reaction. Further, residual monomers were removed by raising the temperature to 98°C and heating for 3.0 hours, and ion-exchanged water was added to adjust the core particle concentration in the dispersion liquid to 30.0%, thereby obtaining a core particle dispersion liquid 1 in which core particles 1 were dispersed. The number average particle diameter (D1) of the core particles 1 was 6.3 μm and the weight average particle diameter (D4) was 6.9 μm.

[0234] Core particle dispersion 2

[0235] The following materials were weighed, mixed and dissolved.

[0236] - 70.0 parts of styrene

[0237] - 25.1 parts of n-butyl acrylate

[0238] - 1.3 parts of acrylic acid

[0239] - 0.4 parts of hexanediol diacrylate

[0240] - 3.2 parts of n-lauryl mercaptan

[0241] Here, a 10% aqueous solution of Neogen RK (from DKS Co., Ltd.) was added to the above solution, and the whole was dispersed using a TK Homomixer (from Tokushu Kika Kogyo Co., Ltd.). While slowly stirring for 10 minutes, an aqueous solution obtained by dissolving 0.15 parts of potassium persulfate in 10.0 parts of ion-exchanged water was further added.

[0242] After nitrogen substitution, emulsion polymerization was performed at 70° C. for 6.0 hours. Upon completion of polymerization, the reaction solution was cooled to room temperature, and ion-exchanged water was added to obtain a resin particle dispersion having a solid concentration of 12.5% ​​and a volume-based median diameter of 0.2 μm.

[0243] The following materials were weighed and mixed.

[0244] - Wax (Behenyl Behenate) 100.0 parts

[0245] -Neogen RK 17.0 parts

[0246] - 385.0 parts of ion exchange water

[0247] The wax particle dispersion was obtained by dispersing for 1 hour using a wet jet mill JN100 (from Jokoh KK). The solid concentration of the wax particle dispersion was 20.0%.

[0248] The following materials were weighed and mixed.

[0249] -CI Pigment Blue 15:3 63.0 parts

[0250] -Neogen RK 17.0 parts

[0251] - 920.0 parts of ion exchange water

[0252] The colorant particle dispersion was obtained by dispersing for 1 hour using a wet jet mill JN100. The solid concentration of the colorant particle dispersion was 10.0%.

[0253] -160.0 parts of resin particle dispersion

[0254] - 10.0 parts of wax particle dispersion

[0255] - 18.9 parts of colorant particle dispersion

[0256] - 0.3 parts of magnesium sulfate

[0257] The above materials were dispersed using a homogenizer (from IKA KK) and subsequently heated to 65°C while stirring. After stirring at 65°C for 1.0 hour, the dispersion was observed using an optical microscope; it was found that aggregated particles showing a number average particle size of 6.0 μm were formed. After adding 2.5 parts of Neogen RK (from DKS Co., Ltd.), the temperature was raised to 80°C and the whole was stirred for 2.0 hours to induce fusion. After cooling, the product was filtered, and the filtered solid was washed with 720.0 parts of ion exchange water by stirring for 1.0 hour. The solid was filtered again and thereafter dried to obtain core particles 2.

[0258] Here, 11.2 parts of sodium phosphate (dodecahydrate) are put into the reaction vessel containing 390.0 parts of ion exchange waters, and while purging with nitrogen, the whole is incubated at 65 DEG C for 1.0 hour. While using TK homomixer (from Tokushu Kika Kogyo Co., Ltd.) to stir with 12500rpm, a disposable addition is made by dissolving 7.4 parts of calcium chloride (dihydrate) in the calcium chloride aqueous solution obtained in 10.0 parts of ion exchange waters, to prepare the aqueous medium comprising a dispersion stabilizer. Further, 1.0mol / L hydrochloric acid is added to the aqueous medium in the reaction vessel, so that the pH is adjusted to 6.0, and aqueous medium 2 is prepared.

[0259] Then, 100.0 parts of the core particles 2 were added to the aqueous medium 2 and the whole was dispersed at 60°C for 30 minutes using a TK homomixer while rotating at 5000 rpm. Ion-exchanged water was added to adjust the solid concentration of the core particles 2 in the dispersion to 30.0%, and a core particle dispersion 2 was obtained. The number average particle diameter (D1) of the core particles 2 was 6.3 μm and the weight average particle diameter (D4) was 7.5 μm.

[0260] Core particle dispersion 3

[0261] Preparation steps of polyester resin 1

[0262] -Terephthalic acid: 11.1 mol parts

[0263] -Bisphenol A propylene oxide 2 molar adduct (PO-BPA): 10.9 mol parts

[0264] The above monomers were added to an autoclave together with an esterification catalyst; a decompression device, a water separation device, a nitrogen introduction device, a temperature measuring device, and a stirrer were then installed in the autoclave, followed by a reaction at 215° C. under a nitrogen atmosphere while reducing pressure according to a normal pressure method until Tg reached 70° C., to obtain a polyester resin 1. The obtained polyester resin 1 had a weight average molecular weight (Mw) of 7,930 and a number average molecular weight (Mn) of 3,090.

[0265] Preparation steps of polyester resin 2

[0266] -725 parts of ethylene oxide 2 mole adduct of bisphenol A

[0267] -285 parts of phthalic acid

[0268] -2.5 parts dibutyltin oxide

[0269] The above materials were reacted at 220°C with stirring for 7 hours, then under reduced pressure for 5 hours, and then cooled to 80°C and reacted with 190 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate-containing polyester resin. Subsequently, 25 parts of the isocyanate-containing polyester resin and 1 part of isophorone diamine were reacted at 50°C for 2 hours to obtain Polyester Resin 2 having a urea-containing polyester as a main component. The obtained Polyester Resin 2 had a weight average molecular weight (Mw) of 22,000 and a number average molecular weight (Mn) of 3,020.

[0270] Preparation steps of core particle 3

[0271] Here, 700 parts of ion-exchanged water, 1000 parts of a 0.1 mol / L sodium phosphate aqueous solution, and 24.0 parts of 1.0 mol / L hydrochloric acid were added to a five-mouth pressure-resistant container equipped with a reflux tube, a stirrer, a thermometer, and a nitrogen inlet tube, and maintained at 63° C. while stirring at 12,000 rpm using a high-speed stirrer, TK Homomixer (from Tokushu Kika Kogyo Co., Ltd.). Then, 85 parts of a 1.0 mol / L calcium chloride aqueous solution were gradually added thereto to prepare an aqueous dispersion medium 3 containing a dispersion stabilizer. Thereafter, a toner particle precursor composition was produced using the following raw materials.

[0272] -Polyester resin 1 60.0 parts

[0273] -Polyester resin 2 40.0 parts

[0274] -CI Pigment Blue 15:3 6.5 parts

[0275] - 0.5 parts of charge control agent

[0276] (Aluminum compound of 3,5-di-tert-butylsalicylic acid)

[0277] - Wax (Behenyl Behenate) 10.0 parts

[0278] The above materials were dissolved in 400 parts of toluene and heated to 63°C to obtain a toner particle precursor composition. Next, this composition was added to aqueous dispersion medium 3 and granulated for 5 minutes while stirring at 12,000 rpm using a high-speed stirrer. The high-speed stirrer was then replaced with a propeller stirrer, and the internal temperature was raised to 70°C. This temperature increase took 10 minutes. While slowly stirring, the temperature was further raised to 95°C, and the toluene was removed by heating over 5.0 hours.

[0279] After cooling, the solid concentration of the core particles 3 was adjusted to 30.0% to obtain a core particle dispersion 3. The core particles 3 had a number average particle diameter (D1) of 6.2 μm and a weight average particle diameter (D4) of 7.4 μm.

[0280] Core particle dispersion 4

[0281] -Binder resin: 100.0 parts of a copolymer of styrene and n-butyl acrylate

[0282] (Styrene: n-butyl acrylate copolymer ratio = 70:30, Mp = 22,000, Mw = 35,000, Mw / Mn = 2.4)

[0283] -CI Pigment Blue 15:3 6.3 parts

[0284] - 5.0 parts of amorphous polyester resin (condensate of terephthalic acid and propylene oxide-modified bisphenol A, Mw: 7800, Tg: 70°C, acid value 8.0 mgKOH / g)

[0285] -Fischer-Tropsch wax (melting point 78°C) 5.0 parts

[0286] The above materials were pre-mixed in an FM mixer (from Nippon Coke & Engineering Co., Ltd.) and then melt-mixed in a twin-screw mixer (PCM-30 type, from Ikegai Corporation) to obtain a mixed product. The mixed product obtained was cooled and coarsely pulverized with a hammer mill (from Hosokawa Micron Corporation), and then pulverized using a mechanical pulverizer (T-250, from Turbo Kogyo Co., Ltd.) to obtain a finely pulverized powder. The finely pulverized powder obtained was classified using a multi-stage classifier based on the Coanda effect (EJ-L-3 type, from Nittetsu Mining Co., Ltd.) to obtain core particles 4.

[0287] Then, 11.2 parts of sodium phosphate (dodecahydrate) were put into a reaction container containing 390.0 parts of ion-exchanged water, and the whole was kept at 65° C. for 1.0 hour while purging with nitrogen.

[0288] Use TK homomixer (from Tokushu Kika Kogyo Co., Ltd.) to stir with 12500rpm.While keeping stirring, disposable addition is by being dissolved in the calcium chloride aqueous solution gained in 10.0 parts of ion exchange waters by 7.4 parts of calcium chloride (dihydrate), to prepare the aqueous medium comprising dispersion stabilizer.Further, 1.0mol / L hydrochloric acid is added in the aqueous medium in the reaction vessel, to be 6.0 and to prepare aqueous medium 4 with pH regulator.

[0289] Then, 200.0 parts of the core particles 4 were added to the aqueous medium 4 and dispersed at 60°C for 30 minutes while rotating at 5000 rpm using a TK homomixer. Ion-exchanged water was added to adjust the toner particle concentration in the dispersion to 30.0%, and a core particle dispersion 4 was obtained. The number average particle diameter (D1) of the core particles 4 was 5.3 μm and the weight average particle diameter (D4) was 6.8 μm.

[0290] Preparation of silica fine particles 1

[0291] Here, 687.9 parts of methanol, 42.0 parts of pure water, and 47.1 parts of 28% by mass aqueous ammonia were added to a 3 L glass reactor equipped with a stirrer, a dropping funnel, and a thermometer, and the entire mixture was mixed. The temperature of the resulting solution was adjusted to 35°C, and then, while stirring, 1100.0 parts of tetraethoxysilane and 395.2 parts of 5.4% by mass aqueous ammonia were simultaneously added. Tetraethoxysilane was added dropwise over 5 hours, and the aqueous ammonia was added dropwise over 4 hours. Once the addition was complete, stirring was continued for a further 0.2 hours to obtain a methanol-water dispersion of hydrophilic spherical sol-gel silica fine particles.

[0292] Next, an ester adapter and a cooling tube were attached to a glass reactor, and the dispersion was heated at 65°C to distill off the methanol. Thereafter, an amount of pure water equal to the amount of distilled methanol was added. The dispersion was dried at 80°C under reduced pressure. The resulting silica fine particles were heated in a constant temperature bath at 400°C for 10 minutes. The resulting silica fine particles (untreated silica) were depolymerized using a pulverizer (from Hosokawa Micron Group).

[0293] Subsequently, 100.0 parts of silica fine particles were added to the reaction vessel, and then, while stirring, a solution of 5.0 parts of dimethyl silicone oil (from Shin-Etsu Chemical Co., Ltd.: KF96-50CS) diluted in 5.0 parts of n-hexane was sprayed into the reaction vessel. Thereafter, the mixture was stirred at 300°C for 60 minutes under a nitrogen stream, dried, and cooled to obtain silica fine particles 1.

[0294] Preparation of silica fine particles 2 and 3

[0295] Silica fine particles 2 to 3 were prepared in the same manner as in the preparation of silica fine particle 1, except that 28% by mass ammonia water was changed to the parts given in Table 1, and the dropping time and the stirring time after the completion of the dropping were changed to the conditions given in Table 1.

[0296] Preparation of silica fine particles 4

[0297] Here, 100 parts of dry silica fine powder (BET specific surface area 300 m2) with a number average particle size of 10 nm was reacted with 30 parts of dimethyl silicone oil (from Shin-Etsu Chemical Co., Ltd.: KF96-50CS). 2 / g) was subjected to hydrophobic treatment.

[0298] Preparation of silica fine particles 5

[0299] The amount of methanol used in the preparation of Silica Fine Particles 1 was changed to 385.5 parts. Furthermore, the dropping time of tetraethoxysilane was changed to 7 hours, and the dropping time of 5.4 mass% ammonia water was changed to 6 hours to obtain Silica Fine Particles 5 having a number average particle diameter of 380 nm.

[0300] The silica fine particles 1 to 5 are spherical particles having a major axis / minor axis ratio of 1.3 or less.

[0301] Preparation of organosilicon polymer fine particles 1

[0302] Silicone polymer fine particles 1 were prepared according to the following steps. First, 360 parts of water were added to a reaction vessel equipped with a thermometer and a stirrer, and 17 parts of 5.0% by mass hydrochloric acid were added to obtain a uniform solution. Then, 136 parts of methyltrimethoxysilane were added while stirring at 25°C. The mixture was stirred for 5 hours and then filtered to obtain a transparent reaction solution containing a silanol compound or a partial condensate thereof.

[0303] In the second step, 540 parts of water were added to a reaction vessel equipped with a thermometer, a stirrer, and a dripping device. Then, 19 parts of 10.0% by mass aqueous ammonia were added to obtain a uniform solution. Subsequently, 100 parts of the reaction solution obtained in the first step were added dropwise over 0.60 hours while stirring at 30°C. The mixture was stirred for 6 hours to obtain a suspension. The fine particles in the resulting suspension were allowed to settle in a centrifuge, removed, and dried in a dryer at 180°C for 24 hours to obtain organosilicon polymer fine particles 1.

[0304] Preparation of silicone polymer fine particles 2 and 3

[0305] Silicone polymer fine particles 2 to 3 were obtained in the same manner as in the preparation of silicone polymer fine particle 1, except that the number of parts of methyltrimethoxysilane was changed as given in Table 2, and the production conditions were also changed as given in Table 2.

[0306] The silicone polymer fine particles 1 to 3 are all spherical particles having a major axis / minor axis ratio of 1.3 or less.

[0307] [Table 1]

[0308]

[0309] [Table 2]

[0310]

[0311] Production Example of Toner Particles

[0312] Toner particles 1

[0313] Shell formation process

[0314] The following sample was weighed in a reaction container, and the temperature of the solution was adjusted to 70° C. while stirring with a propeller stirring blade.

[0315] - 1 333.3 parts of core particle dispersion

[0316] Next, a dispersion was prepared by mixing 0.4 parts of a shell-forming polymerizable monomer, 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane, with 6.0 parts of ion-exchanged water and dispersing the mixture using a homogenizer. The dispersion was placed in a reaction vessel and stirred at 70°C using a propeller. While stirring, 0.20 parts of potassium persulfate, a polymerization initiator, was added all at once to the reaction vessel.

[0317] The solution was kept at 70°C and stirred for 3.0 hours using a propeller stirring blade. The solution was cooled to 25°C and then adjusted to pH 1.5 with 1 mol / L hydrochloric acid, stirred for 1.0 hour, and then filtered while washing with ion-exchanged water to obtain toner particles 1 having shells.

[0318] Toner particles 2 to 17 and 26

[0319] Toner particles 2 to 17 and 26 were obtained in the same manner as in the production example of toner particle 1, except that the amounts of the polymerizable monomer as the shell material and the initiator were changed as given in Table 3 herein.

[0320] Toner particles 18 to 20

[0321] Toner particles 18 to 20 were obtained in the same manner as in the production example of toner particle 1, except that the production conditions were changed to those given in Table 3.

[0322] Toner particles 21

[0323] Toner particles 21 were obtained in the same manner as in the production example of toner particles 1, except that the shell forming step was changed here as given below.

[0324] Shell formation step

[0325] The core particle dispersion 1 was added to a reaction container, the pH was adjusted to 1.5 using 1 mol / L hydrochloric acid, and the whole was stirred for 1.0 hour, followed by filtration while washing with ion-exchanged water, and as a result, toner particles 21 were obtained.

[0326] Toner particles 22 to 24

[0327] Toner particles 22 to 24 were obtained in the same manner as in the production example of toner particle 1, except that the production conditions were changed to those given in Table 3 here.

[0328] Toner particles 25

[0329] Toner particles 25 were obtained in the same manner as in the production example of toner particles 1, except that the shell forming step was changed here as given below.

[0330] Shell formation step

[0331] The following sample was weighed in a reaction container, and the temperature of the solution was adjusted to 70° C. while stirring with a propeller stirring blade.

[0332] - 1 333.3 parts of core particle dispersion

[0333] Next, 3.00 parts of 3-(methacryloyloxy)propyltrimethoxysilane, a polymerizable monomer for shell formation, was added and the whole was stirred at a temperature of 70°C using a propeller stirring blade. While stirring, 0.50 parts of potassium persulfate as a polymerization initiator was added to the reaction vessel at one time. The temperature of the solution was maintained at 70°C, and the solution was maintained for 3.0 hours while mixing using a propeller stirring blade. Next, the pH was adjusted to 8.0 by adding a 1 mol / L NaOH aqueous solution. Thereafter, the interior of the container was maintained at 70°C for 3.0 hours. Then, 0.10 parts of methoxytrimethylsilane was added, and the interior of the container was stirred at 70°C for 3.0 hours.

[0334] The temperature was lowered to 25° C., and thereafter the pH was adjusted to 1.5 with 1 mol / L hydrochloric acid, stirred for 1.0 hour, and subsequently filtered while washing with ion-exchanged water to obtain toner particles 25 having a shell.

[0335] Production of Toner 1

[0336] Here, in a Henschel mixer (from Mitsui Miike Chemical Engineering Machinery Co., Ltd.), 100 parts of Toner Particles 1, 1.0 part of Silica Fine Particles 1, and 1.0 part of Silicone Polymer Fine Particles 1 were mixed for 5 minutes to obtain Toner 1. The jacket temperature of the Henschel mixer was set to 10° C., and the peripheral speed of the rotary blade was set to 38 m / sec.

[0337] Production of Toners 2 to 36 and Comparative Toners 1 to 8

[0338] In the production of Toner 1, the kind of toner particles was changed according to Table 4, and the kinds of silica fine particles and silicone polymer fine particles were similarly changed. The addition amounts were also changed according to Table 4. Except for this, Toners 2 to 36 and Comparative Toners 1 to 8 were obtained in the same manner as in the production of Toner 1.

[0339] Table 5 lists the physical properties of Toner Particles 1 to 26, and Table 6 lists the physical properties of Toners 1 to 36 and Comparative Toners 1 to 8. In the measurement of the shell content, each toner contained a shell having a value corresponding to the addition amount of Table 3.

[0340] [Table 3]

[0341]

[0342] In Table 3, numbers separated by slashes in the column of "Type of polymerizable monomer" indicate that two polymerizable monomers were used. Numerical values ​​separated by slashes in the column of "Amount" indicate the respective charged amounts.

[0343] [Table 4]

[0344] Toner particle No. Silica fine particles No. Added amount (portions) Silicone polymer fine particles No. Added amount (portions) Toner 1 1 1 1.0 1 1.0 Toner 2 2 1 1.0 1 1.0 Toner 3 3 1 1.0 1 1.0 Toner 4 4 1 1.0 1 1.0 Toner 5 5 1 1.0 1 1.0 Toner 6 6 1 1.0 1 1.0 Toner 7 7 1 1.0 1 1.0 Toner 8 1 4 0.1 1 1.0 Toner 9 1 2 1.0 - - Toner 10 1 1 1.0 - - Toner 11 1 3 1.0 - - Toner 12 1 1 0.1 - - Toner 13 1 1 0.5 - - Toner 14 1 1 2.0 - - Toner 15 1 1 6.0 - - Toner 16 1 - - 2 1.0 Toner 17 1 - - 1 1.0 Toner 18 1 - - 3 1.0 Toner 19 1 - - 1 0.1 Toner 20 1 - - 1 0.5 Toner 21 1 - - 1 2.0 Toner 22 1 - - 1 6.0 Toner 23 8 1 1.0 1 1.0 Toner 24 9 1 1.0 1 1.0 Toner 25 10 1 1.0 1 1.0 Toner 26 11 1 1.0 1 1.0 Toner 27 12 1 1.0 1 1.0 Toner 28 13 1 1.0 1 1.0 Toner 29 14 1 1.0 1 1.0 Toner 30 15 1 1.0 1 1.0 Toner 31 16 1 1.0 1 1.0 Toner 32 17 1 1.0 1 1.0 Toner 33 18 1 1.0 1 1.0 Toner 34 19 1 1.0 1 1.0 Toner 35 20 1 1.0 1 1.0 Toner 36 26 1 1.0 1 1.0 Comparison Toner 1 21 1 1.0 1 1.0 Compare Toner 2 22 1 1.0 1 1.0 Compare Toner 3 23 1 1.0 1 1.0 Compare Toner 4 24 1 1.0 1 1.0 Comparison Toner 5 25 1 1.0 1 1.0 Comparative Toner 6 1 4 1.0 - - Compare Toner 7 1 5 1.0 - - Compare Toner 8 1 1 0.02 - -

[0345] [Table 5]

[0346] The monomer unit represented by formula (1) Shell coverage (%) (I) Monomer unit content (mass %) Mw of the polymer in the shell Toner particles 1 Y 95％ 100 48000 Toner particles 2 Y 96％ 100 97000 Toner particles 3 Y 94％ 100 19400 Toner particles 4 Y 94％ 100 11900 Toner particles 5 Y 94％ 100 9100 Toner particles 6 Y 92％ 100 19000 Toner particles 7 Y 89％ 100 19000 Toner particles 8 Y 72％ 30 9800 Toner particles 9 Y 85％ 50 32000 Toner particles 10 Y 91％ 75 16000 Toner particles 11 Y 89％ 75 16000 Toner particles 12 Y 88％ 75 97000 Toner particles 13 Y 82％ 100 24000 Toner particles 14 Y 89％ 100 73000 Toner particles 15 Y 92％ 100 98000 Toner particles 16 Y 95％ 100 99000 Toner particles 17 Y 96％ 100 101000 Toner particles 18 Y 95％ 100 19400 Toner particles 19 Y 94％ 100 19400 Toner particles 20 Y 93％ 100 19000 Toner particles 21 N 0％ 0 - Toner particles 22 N 98％ 0 19000 Toner particles 23 N 98％ 0 19200 Toner particles 24 N 96％ 0 19000 Toner particles 25 N 94％ 0 102000 Toner particles 26 Y 63％ 100 20300

[0347] In Table 5, the column of monomer units represented by formula (I) is marked with Y when the polymer in the shell contains monomer units represented by formula (I), and is marked with N when the polymer does not contain these monomer units. The note "(I) monomer unit content" indicates the content ratio of the monomer unit represented by formula (I) among the monomer units included in the polymer of the shell.

[0348] [Table 6]

[0349]

[0350] In Table 6, the coverage ratio indicated by *1 is the coverage ratio of particles not included as the external additive A.

[0351] Examples 1 to 36, Comparative Examples 1 to 8

[0352] Evaluation was performed using the above-mentioned Toners 1 to 36 and Comparative Toners 1 to 8. The evaluation results are given in Table 7. The evaluation method and evaluation criteria are described below.

[0353] Evaluation of image streaks after durability test

[0354] When outputting a full-surface halftone image, image defects were readily observed, appearing as vertical streaks approximately 0.1 to 0.5 mm in width. A modified LBP712Ci (from Canon Inc.) was used as the image forming apparatus. The main unit's processing speed was modified to 270 mm / s. Necessary adjustments were made to ensure image formation under these conditions. Furthermore, the toner was removed from the cyan cartridge and replaced with 100 g of the evaluation toner.

[0355] The image streaks when used in a normal temperature and humidity environment (23°C, 60% RH) were evaluated. The evaluation paper used was XEROX4200 paper (75 g / m 2 , from XEROX Corporation). Under normal temperature and humidity conditions, 15,000 sheets of a text image with a print rate of 0.5% were intermittently output, two sheets every 4 seconds, followed by a 50% halftone image across the entire surface, and the presence of streaks was observed. Image streaks after the durability test (durability test streaks) were used as the evaluation results. The evaluation results are shown in Table 7.

[0356] Evaluation Criteria

[0357] A: No streaks occurred.

[0358] B: No streaks appear on the image, but 1 to 2 streaks are visible on the developing roller.

[0359] C: There is a streak on the image.

[0360] D: There are two stripes on the image.

[0361] E: There are three or more streaks on the image.

[0362] Malregulated reviews

[0363] A modified LBP712Ci machine (from Canon Inc.) was used as the image forming apparatus. The main processing speed was modified to 270 mm / s. Necessary adjustments were made to allow image formation under these conditions. Furthermore, the toner was removed from the cyan cartridge and then replaced with 100 g of the evaluation toner.

[0364] To evaluate poor conditioning, the toner coating on the developing roller surface was observed after 15,000 sheets were printed in a low-temperature, low-humidity environment (15°C, 10% RH). The presence or absence of coating defects caused by excessive toner charging was visually observed according to the following criteria. The image used in the durability test was a 0.5% horizontal line printed intermittently every 4 seconds for a total of 15,000 sheets. Thereafter, a 50% halftone image was printed over the entire surface and confirmed.

[0365] A: No coating defects were observed on the developing roller.

[0366] B: There are slight coating defects on the developing roller, but no defects appear on the image.

[0367] C: There are noticeable coating defects on the developing roller, but no defects appear on the image.

[0368] D: A coating defect exists on the developing roller, and image defects originating from the coating defect are observed.

[0369] Evaluation of low-temperature fixability

[0370] A color laser printer LBP712Ci (from Canon Inc.) was prepared with the fixing unit removed, the toner was removed from the cyan cartridge, and the toner to be evaluated was filled instead. Color laser copier paper (from Canon, 80 g / m 2 ) was used as a recording medium. Next, an unfixed image of 2.0 cm long and 15.0 cm wide was formed at a portion 1.0 cm from the upper end in the paper passing direction using a filled toner so that the toner load was 0.20 mg / cm 2Next, the taken-out fixing unit was changed so that the fixing temperature and the process speed could be adjusted, and a fixing test of an unfixed image was conducted using the modified fixing unit.

[0371] First, under normal temperature and humidity environment (23°C, 60% RH), the processing speed is set to 270 mm / s and the fixing line pressure is set to 27.4 kgf. Then, the set temperature is gradually increased at intervals of 5°C from the initial temperature of 140°C, and the unfixed image is fixed at each temperature.

[0372] The evaluation criteria for low temperature fixing property are as follows: The low temperature side fixing starting point here means that the film is fixed at a speed of 0.2 m / s using a pressure of 4.9 kPa (50 g / cm 2 The lowest temperature at which the image density decreases by 10.0% or less before and after rubbing the image surface five times with lens cleaning paper (Dusper K-3) loaded with a 0.5% ion flux. If fixing is not performed properly, the image density decrease tends to increase. Image density is measured using a Series 500 spectrodensitometer (from X-Rite Inc.).

[0373] Evaluation Criteria

[0374] A: The fixing starting point on the low temperature side is 145° C. or lower.

[0375] B: The fixing starting point on the low temperature side is 150°C.

[0376] C: The fixing starting point on the low temperature side is 155°C.

[0377] D: The fixing starting point on the low temperature side is 160° C. or higher.

[0378] [Table 7]

[0379]

[0380] The present disclosure relates to the following configurations.

[0381] Composition 1

[0382] A toner comprising toner particles, wherein

[0383] The toner particles have a core-shell structure including a core particle and a shell on the surface of the core particle,

[0384] The shell includes a polymer having a monomer unit represented by the following formula (I),

[0385] The toner includes an external additive A having a particle size of 30 to 300 nm,

[0386] The external additive A is at least one selected from the group consisting of silica fine particles and organosilicon polymer fine particles, and

[0387] The coverage of the toner particle surface by the external additive A is 0.3 area % or more:

[0388]

[0389] In formula (I), L 1 Represents -COO(CH2) n - (wherein n is an integer from 1 to 10), and L 1 The carbonyl group is bonded to the carbon atom of the main chain; R 1 represents hydrogen or methyl; and R 2 to R 10 Each independently represents an alkyl group having 1 to 4 carbon atoms.

[0390] Composition 2

[0391] The toner according to Configuration 1, wherein the content ratio of the monomer unit represented by formula (I) in the polymer is 50% by mass or more.

[0392] Composition 3

[0393] The toner according to configuration 1 or 2, wherein the coverage of the core particle surface by the shell is 80 area % or more in a backscattered electron image of the toner particles taken at a magnification of 10,000 times using a scanning electron microscope.

[0394] Composition 4

[0395] The toner according to any one of Configurations 1 to 3, wherein the content of the shell is 0.10 to 4.00 parts by mass relative to 100 parts by mass of the core particles.

[0396] Composition 5

[0397] The toner according to any one of Configurations 1 to 4, wherein

[0398] The core particle includes a binder resin, and

[0399] The binder resin includes a vinyl resin.

[0400] Composition 6

[0401] The toner according to any one of Configurations 1 to 5, wherein the external additive A includes silica fine particles.

[0402] Composition 7

[0403] The toner according to any one of Configurations 1 to 6, wherein the external additive A includes silica fine particles and organic silicon polymer fine particles.

[0404] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A toner comprising toner particles, characterized in that: The toner particles have a core-shell structure including a core particle and a shell on a surface of the core particle, The shell includes a polymer having a monomer unit represented by the following formula (I), The toner includes an external additive A having a particle size of 30 nm to 300 nm, The external additive A is at least one selected from the group consisting of silica fine particles and organosilicon polymer fine particles, and The coverage of the surface of the toner particles by the external additive A is 0.3 area % or more: In formula (I), L 1 Represents -COO(CH2) n -, wherein n is an integer from 1 to 10, and L 1 The carbonyl group is bonded to the carbon atom of the main chain; R 1 represents hydrogen or methyl; and R 2 to R 10 Each independently represents an alkyl group having 1 to 4 carbon atoms. 2 . The toner according to claim 1 , wherein a content ratio of the monomer unit represented by the formula (I) in the polymer is 50% by mass or more. 3 . The toner according to claim 1 , wherein in a backscattered electron image of the toner particles taken at a magnification of 10,000 times using a scanning electron microscope, the coverage rate of the surface of the core particle by the shell is 80 area % or more. 4 . The toner according to claim 1 , wherein the content of the shell is 0.10 to 4.00 parts by mass relative to 100 parts by mass of the core particles.

5. The toner according to claim 1 or 2, wherein The core particle includes a binder resin, and The binder resin includes a vinyl resin. 6 . The toner according to claim 1 , wherein the external additive A includes the silica fine particles. 7 . The toner according to claim 1 , wherein the external additive A comprises the silica fine particles and the organosilicon polymer fine particles.

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