Toner for electrostatic charge image development

Abstract

To provide a toner for an electrostatic charge image development excellent in hot offset resistance and durability.SOLUTION: Disclosed is a toner for an electrostatic charge image development which includes toner particles. The toner particles have a core shell structure. A shell part contains a silicone modified amorphous composite resin which includes: a polyester resin segment; an addition polymerization resin segment including a constitutional unit derived from a styrene-based compound; and a polyorganosiloxane segment.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a toner for electrostatic charge image development.

Background Art

[0002] In the field of electrophotography, with the development of electrophotographic systems, there is a demand for the development of toners for electrostatic charge image development that can cope with high image quality and high speed.

[0003] Patent Document 1 discloses an electrophotographic toner composition characterized by containing a binder resin, a colorant, a silicone oil, and a silicone-modified resin for the purpose of improving offset resistance and blocking resistance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Patent Document 1 relates to capsule toner and contains a silicone-modified resin inside the capsule, so there is room for improvement in offset resistance. The present invention relates to a toner for electrostatic charge image development that is excellent in hot offset resistance and durability.

Means for Solving the Problems

[0006] One embodiment of the present invention relates to the following [1] and [2]. [1] An electrostatic charge image developing toner containing toner particles, wherein the toner particles have a core-shell structure, and the shell portion contains a polyester resin segment, an addition polymerization resin segment containing a structural unit derived from a styrene-based compound, and a polyorganosiloxane segment, and contains a silicone-modified amorphous composite resin. An electrostatic charge image developing toner. [2] A method for producing the electrostatic charge image developing toner according to [1], comprising the following steps 1 to 3. Step 1: A step of aggregating resin particles X containing a binder resin of a core portion in an aqueous medium to obtain aggregated particles 1. Step 2: A step of aggregating resin particles Y containing a silicone-modified amorphous composite resin with respect to the aggregated particles 1 obtained in Step 1 to obtain aggregated particles 2. Step 3: A step of heating and fusing the aggregated particles 2 obtained in Step 2 to obtain fused particles. [Advantages of the Invention]

[0007] According to the present invention, it is possible to provide an electrostatic charge image developing toner excellent in hot offset resistance and durability. [Embodiments for Carrying Out the Invention]

[0008] [Electrostatic Charge Image Developing Toner] The electrostatic charge image developing toner of the present invention (hereinafter, also simply referred to as "toner") is an electrostatic charge image developing toner containing toner particles, and the toner particles have a core-shell structure, and the shell portion contains a polyester resin segment, an addition polymerization resin segment containing a structural unit derived from a styrene-based compound, and a polyorganosiloxane segment, and contains a silicone-modified amorphous composite resin (hereinafter, also referred to as composite resin B). According to the present invention, it is possible to provide an electrostatic charge image developing toner excellent in hot offset resistance and durability. Note that the durability means that the toner has excellent mechanical strength and the core-shell structure is maintained even when it is agitated in the developing machine for a long time.

[0009] Although the detailed mechanism by which the above effects are obtained is unknown, part of it can be considered as follows. Since the shell part of the toner particles having a core-shell structure contains a silicone-modified amorphous composite resin (composite resin B), silicone chains can be present near the toner surface, resulting in good releasability during fixing. As a result, the mold release property during fixing is greatly improved, and it is considered to be excellent in hot offset resistance. As will be described later, when manufactured by a manufacturing method having an aggregation step and a fusion step in an aqueous medium, although silicone chains are present near the toner surface, it is considered that they are hardly present on the outermost surface. In addition, since the shell part contains a silicone-modified amorphous composite resin modified with silicone having a low surface tension, the shell part easily wets and spreads on the core part during fusion, and the shell part uniformly covers the core part, resulting in good formation of the core-shell structure. As a result, it is considered that the durability is improved.

[0010] The definitions of various terms in this specification are shown below. Whether the resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the maximum peak temperature of endotherm in the measurement method described in the examples below (softening point (°C) / maximum peak temperature of endotherm (°C)). A crystalline resin is one having a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one in which no endothermic peak is observed, or if observed, having a crystallinity index of less than 0.6 or more than 1.4. The crystallinity index can be appropriately adjusted by the type and ratio of the raw material monomers, and manufacturing conditions such as reaction temperature, reaction time, and cooling rate. In the specification, the carboxylic acid component of the polyester resin includes not only the compound itself, but also anhydrides that decompose during the reaction to generate acids, and alkyl esters of each carboxylic acid (alkyl group having 1 to 3 carbon atoms). "Volume median particle diameter (D 50 )" means the particle diameter at which the cumulative volume frequency calculated by volume fraction becomes 50% when calculated from the smaller particle diameter. The coefficient of variation of the particle size distribution (hereinafter, also simply referred to as "CV value") is a value represented by the following formula. The volume average particle size in the following formula is the particle size obtained by dividing the total value of the product of the particle size and the volume of each particle for all the measured particles by the total volume of the measured particles. CV value (%) = [standard deviation of particle size distribution (μm) / volume average particle size (μm)] × 100 The "carboxylic acid compound" includes not only the carboxylic acid itself, but also anhydrides that decompose during the reaction to generate an acid, and alkyl esters of each carboxylic acid (alkyl group having 1 to 3 carbon atoms). "Bisphenol A" is 2,2-bis(4-hydroxyphenyl)propane. The "binder resin" means the resin components contained in the toner including the composite resin B and the resins A and C described later.

[0011] The toner of the present invention contains toner particles, and the toner has a core-shell structure. Note that the toner may be composed of, for example, only toner particles, but preferably contains toner particles and external additives.

[0012] 〔Toner particles〕 The toner particles have a core-shell structure, and the shell portion contains a silicone-modified amorphous composite resin (composite resin B) including a polyester resin segment, an addition polymerization resin segment containing a structural unit derived from a styrene-based compound, and a polyorganosiloxane segment. The binder resin of the core portion is not particularly limited, but preferably contains an addition polymerization resin of a raw material monomer containing a styrene-based compound (hereinafter, also referred to as "resin A"), and further preferably contains a crystalline polyester resin (hereinafter, also referred to as "resin C"). The toner particles may further contain additives such as a release agent, a colorant, a charge control agent, magnetic powder, a fluidity improver, a conductivity adjuster, a reinforcing filler such as a fibrous substance, an antioxidant, an anti-aging agent, and a cleaning property improver.

[0013] <Silicone-modified amorphous composite resin (composite resin B)> Composite resin B is a silicone-modified amorphous composite resin (Composite resin B) containing a polyester resin segment, an addition polymerization resin segment containing a structural unit derived from a styrene-based compound, and a polyorganosiloxane segment, from the viewpoint of obtaining a toner excellent in hot offset resistance and durability. Composite resin B is preferably a reaction product of an alcohol component containing a dihydric or higher alcohol, a carboxylic acid component containing a dicarboxylic acid compound or higher, a raw material monomer containing a styrene-based compound, and a modified silicone having a hydroxy group, a carboxy group, or an epoxy group at one or both ends.

[0014] (Alcohol component) The alcohol component contains a dihydric or higher alcohol. The content of the dihydric or higher alcohol is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and 100% by mass or less in the alcohol component. Examples of the dihydric or higher alcohol include alkylene oxide adducts of aromatic diols, linear or branched aliphatic diols, alicyclic diols, and trihydric or higher polyhydric alcohols. Among these, alkylene oxide adducts of aromatic diols, or linear or branched aliphatic diols are preferred, and alkylene oxide adducts of aromatic diols are more preferred.

[0015] The alkylene oxide adduct of the aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably the formula (I):

[0016] [Chemical formula] (In the formula, OR 1 and R 2 O is an oxyalkylene group, R 1 and R 2Each is independently an ethylene group or a propylene group, x and y represent the average number of moles of alkylene oxide added, each is a positive number, the value of the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 4 or less), and is an alkylene oxide adduct of bisphenol A represented by Examples of the alkylene oxide adduct of bisphenol A include a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A. One or more of these may be used. Among these, a combination of a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A is preferable. The molar ratio of the propylene oxide adduct of bisphenol A to the ethylene oxide adduct of bisphenol A (propylene oxide adduct of bisphenol A / ethylene oxide adduct of bisphenol A) is preferably 10 / 90 or more, more preferably 15 / 85 or more, still more preferably 20 / 80 or more, and preferably 90 / 10 or less, more preferably 70 / 30 or less, still more preferably 50 / 50 or less, still more preferably 35 / 65 or less. When the alkylene oxide adduct of bisphenol A is included, its amount is preferably 70 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more in the alcohol component, and 100 mol% or less, and more preferably 100 mol%.

[0017] As the linear or branched aliphatic diol, an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferable. The number of carbon atoms of the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferably 3 or more and 4 or less. Examples of the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, and 2,3-butanediol. When using an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom as the alcohol component, the amount thereof is preferably 70 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, and 100 mol% or less, and still more preferably 100 mol% in the alcohol component.

[0018] Examples of other linear or branched aliphatic diols include ethylene glycol, 1,3 - propanediol, 1,4 - butanediol, 1,6 - hexanediol, 1,8 - octanediol, 1,9 - nonanediol, 1,10 - decanediol, and 1,12 - dodecanediol.

[0019] Examples of alicyclic diols include hydrogenated bisphenol A [2,2 - bis(4 - hydroxycyclohexyl)propane], and adducts of hydrogenated bisphenol A with an alkylene oxide having 2 to 4 carbon atoms (average addition mole number: 2 to 12). Examples of polyhydric alcohols having a valency of 3 or more include glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These alcohol components may be used alone or in combination of two or more.

[0020] (Carboxylic acid component) The carboxylic acid component contains a polycarboxylic acid compound having a valency of 2 or more. The content of the polycarboxylic acid compound having a valency of 2 or more is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and 100% by mass or less in the carboxylic acid component. Examples of polycarboxylic acid compounds having a valency of 2 or more include aromatic dicarboxylic acid compounds, linear or branched aliphatic dicarboxylic acid compounds, alicyclic dicarboxylic acid compounds, and polycarboxylic acid compounds having a valency of 3 or more. Among these, aromatic dicarboxylic acid compounds are preferred.

[0021] Examples of the aromatic dicarboxylic acid compound include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid or terephthalic acid is preferable, and terephthalic acid is more preferable. The amount of the aromatic dicarboxylic acid compound is preferably 30 mol% or more, more preferably 60 mol% or more, still more preferably 80 mol% or more, and even more preferably 85 mol% or more in the carboxylic acid component, and is preferably 99 mol% or less, more preferably 97 mol% or less, and still more preferably 95 mol% or less.

[0022] The number of carbon atoms of the linear or branched aliphatic dicarboxylic acid compound is preferably 2 or more, more preferably 4 or more, still more preferably 8 or more, and even more preferably 10 or more, and is preferably 22 or less, more preferably 16 or less. Examples of the linear or branched aliphatic dicarboxylic acid compound include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an anhydride thereof or an alkyl ester having 1 to 3 carbon atoms. Examples of the succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms include dodecyl succinic acid, dodecenyl succinic acid, and octenyl succinic acid. Among these, succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an anhydride thereof is preferable. When the linear or branched aliphatic dicarboxylic acid compound is included, its amount is preferably 2 mol% or more, more preferably 3 mol% or more, and still more preferably 5 mol% or more in the carboxylic acid component, and is preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol% or less.

[0023] The polyvalent carboxylic acid compound having a valency of 3 or more is preferably a trivalent carboxylic acid, and examples thereof include trimellitic acid or its anhydride. Among these, trimellitic acid or its anhydride is preferable. When a polyvalent carboxylic acid compound having a valence of 3 or more is included, the amount of the polyvalent carboxylic acid compound having a valence of 3 or more is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 8 mol% or more in the carboxylic acid component, and is preferably 35 mol% or less, more preferably 30 mol% or less. These carboxylic acid compounds may be used alone or in combination of two or more.

[0024] The ratio of the carboxy group of the carboxylic acid component to the hydroxy group of the alcohol component (COOH group / OH group) is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0025] (Raw material monomer) The addition polymerization segment preferably contains a structural unit derived from a styrene compound and is an addition polymer of a raw material monomer containing a styrene compound. Examples of the styrene compound include unsubstituted or substituted styrene. Examples of the substituent for styrene include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group or a salt thereof. Examples of the styrene compound include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrene sulfonic acid or a salt thereof. Among these, styrene is preferred. In the raw material monomer of the addition polymerization resin segment, the content of the styrene compound is preferably 50% by mass or more, more preferably 65% by mass or more, still more preferably 75% by mass or more, and is 100% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less.

[0026] Examples of raw material monomers other than styrene compounds include (meth)acrylic acid esters such as alkyl (meth)acrylate, benzyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate; olefins such as ethylene, propylene, and butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether; vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. Among these, (meth)acrylic acid esters are preferred, and alkyl (meth)acrylates are more preferred. The number of carbon atoms in the alkyl group of the alkyl (meth)acrylate is preferably 1 or more, more preferably 4 or more, still more preferably 6 or more, and preferably 24 or less, more preferably 22 or less, still more preferably 20 or less. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, (iso)propyl (meth)acrylate, (iso- or tertiary)butyl (meth)acrylate, (iso)amyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, (iso)dodecyl (meth)acrylate, (iso)palmityl (meth)acrylate, (iso)stearyl (meth)acrylate, and (iso)behenyl (meth)acrylate. Preferred are 2-ethylhexyl (meth)acrylate or stearyl (meth)acrylate, more preferred are 2-ethylhexyl acrylate and stearyl methacrylate, and still more preferred is 2-ethylhexyl acrylate. Note that “(iso- or tertiary)” and “(iso)” mean both cases where these prefixes are present and cases where they are not present. When these prefixes are not present, it indicates normal. Also, “(meth)acrylic acid” indicates acrylic acid or methacrylic acid.

[0027] In the raw material monomers of the addition polymerization resin segment, the content of (meth)acrylic acid ester is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 35% by mass or less, still more preferably 25% by mass or less. In the raw material monomers of the addition polymerization resin segment, the total amount of the styrene-based compound and the (meth)acrylic acid ester is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and still more preferably 100% by mass.

[0028] The composite resin B preferably has structural units derived from both reactive monomers bonded via a covalent bond to the polyester resin segment and the addition polymerization resin segment. The "structural units derived from both reactive monomers" means units in which the functional groups and addition polymerizable groups of both reactive monomers have reacted. Examples of the addition polymerizable group include a carbon-carbon unsaturated bond (ethylenic unsaturated bond). Examples of the both reactive monomers include addition polymerizable monomers having at least one functional group selected from a hydroxyl group, a carboxy group, an epoxy group, a primary amino group, and a secondary amino group in the molecule. Among these, from the viewpoint of reactivity, addition polymerizable monomers having at least one functional group selected from a hydroxyl group and a carboxy group are preferable, and addition polymerizable monomers having a carboxy group are more preferable. Examples of the addition polymerizable monomer having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Among these, from the viewpoint of the reactivity of both the polycondensation reaction and the addition polymerization reaction, acrylic acid and methacrylic acid are preferable, and acrylic acid is more preferable. When the both-reactive monomer is an addition polymerizable monomer having a carboxy group, the amount of the structural unit derived from the both-reactive monomer is preferably 1 mol part or more, more preferably 3 mol parts or more, still more preferably 5 mol parts or more, and preferably 30 mol parts or less, more preferably 20 mol parts or less, still more preferably 10 mol parts or less, based on 100 mol parts of the alcohol component of the polyester resin segment of the composite resin B.

[0029] The content of the polyester resin segment in the composite resin B is preferably 40% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less, based on the total amount of the polyester resin segment and the addition polymer resin segment. Note that the structural unit derived from the both-reactive monomer is calculated including in the polyester resin segment.

[0030] The content of the addition polymer resin segment in the composite resin B is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and preferably 60% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, based on the total amount of the polyester resin segment and the addition polymer resin segment. Note that the structural unit derived from the both-reactive monomer is calculated including in the polyester resin segment.

[0031] The above amounts are calculated based on the ratio of the amounts of the polyester resin segment, the raw material monomers of the addition polymer resin segment, the both-reactive monomer, and the radical polymerization initiator, and are based on the mass excluding the amount of water removed by polycondensation in the polyester resin segment and the like. When a radical polymerization initiator is used, the mass of the radical polymerization initiator is calculated including in the addition polymer resin segment.

[0032] (Modified silicone) Composite resin B contains a polyorganosiloxane segment. The modified silicone used in the production of composite resin B is preferably a modified silicone having a hydroxy group, a carboxy group, or an epoxy group in a side chain, one terminal, or both terminals, from the viewpoint of reacting with at least one of an alcohol component and a carboxylic acid component, and from the viewpoint of obtaining a toner for electrostatic charge image development excellent in hot offset resistance and durability, and more preferably a modified silicone having one terminal or both terminals.

[0033] More specifically, the modified silicone is preferably represented by the formula (1):

[0034]

Chemical formula

[0035] The number of carbon atoms of the hydrocarbon group of R is 6 or less, preferably 5 or less, more preferably 4 or less, still more preferably 3 or less, still more preferably 2 or less, and still more preferably 1. Examples of the hydrocarbon group of R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a pentyl group, and a phenyl group. Among these, a methyl group is preferable. The number of carbon atoms of the alkylene group of R' is 10 or less, preferably 8 or less, more preferably 5 or less, still more preferably 4 or less, and still more preferably 3 or less, and is preferably 1 or more, more preferably 2 or more. Examples of the alkylene group of R’ include a methanediyl group, an ethane-1,2-diyl group, an ethane-1,1-diyl group, an n-propane-1,3-diyl group, an n-propane-1,2-diyl group, a 2-methylethane-1,2-diyl group, a 1,4-n-butyl group, a 1,2-tert-butyl group, and a 1,5-pentyl group. Among these, an ethane-1,2-diyl group, an n-propane-1,3-diyl group, and an n-propane-1,2-diyl group are preferred, and an n-propane-1,2-diyl group is more preferred. The number of carbon atoms of the hydrocarbon group of R’’ is 10 or less, preferably 8 or less, more preferably 6 or less, still more preferably 4 or less, still more preferably 3 or less, still more preferably 2 or less, and still more preferably 1. Examples of the hydrocarbon group of R’’ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a pentyl group, and a benzyl group. X is a hydroxy group, a hydroxyalkyloxy group, a carboxy group, a carboxyalkyloxy group, an epoxy group, a glycidyl group, a glycidyloxy group, or an alicyclic epoxy group. The hydroxyalkyloxy group and the hydroxyalkyloxy group may have a plurality of hydroxy groups. The carboxyalkyloxy group may have a plurality of carboxy groups. s is 3 or less, preferably 2 or less, and more preferably 1. t is 3 or less, preferably 2 or less, and more preferably 0 or 1. n is 300 or less, preferably 200 or less, more preferably 100 or less, still more preferably 50 or less, and is 5 or more, preferably 8 or more, and more preferably 10 or more.

[0036] The weight average molecular weight (Mw) of the modified silicone is preferably 600 or more, more preferably 800 or more, still more preferably 1,000 or more, and is preferably 20,000 or less, more preferably 10,000 or less, still more preferably 7,000 or less, still more preferably 6,000 or less, still more preferably 5,000 or less, and still more preferably 4,000 or less. The number average molecular weight (Mn) of the modified silicone is preferably 500 or more, more preferably 700 or more, still more preferably 1,000 or more, and preferably 10,000 or less, more preferably 5,000 or less, still more preferably 4,000 or less, and still more preferably 3,000 or less.

[0037] The kinematic viscosity of the modified silicone is preferably 10 mm 2 / s or more, more preferably 20 mm 2 / s or more, still more preferably 30 mm 2 / s or more, and preferably 500 mm 2 / s or less, more preferably 200 mm 2 / s or less, still more preferably 100 mm 2 / s or less. The kinematic viscosity of the modified silicone is measured at 25°C using a fully automatic micro kinematic viscometer (manufactured by Bisco Co., Ltd.).

[0038] The functional group equivalent of the modified silicone is preferably 300 g / mol or more, more preferably 500 g / mol or more, still more preferably 700 g / mol or more, and preferably 5,000 g / mol or less, more preferably 4,000 g / mol or less, still more preferably 3,000 g / mol or less. Note that the functional group equivalent means the mass of the modified silicone per mole of the functional group.

[0039] As the modified silicone used in the composite resin B, from the viewpoint of obtaining a toner excellent in hot offset resistance and durability, a modified silicone (a) having a hydroxy group at one or both ends (hereinafter also simply referred to as "modified silicone (a)") is preferable. That is, the modified silicone (a) is preferably of the formula (1a):

[0040]

Chemical formula

[0041]

Chemical formula

[0042] From the viewpoint of further improving the hot offset resistance, the modified silicone (a) preferably has hydroxy groups at both ends. That is, from the viewpoint of further improving the hot offset resistance, the modified silicone (a) has one group represented by R’X at each of both ends. That is, in the above formula (1a), s and t are 1. 1 Moreover, from the viewpoint of further improving the durability, the modified silicone (a) preferably has a hydroxy group at one end. That is, from the viewpoint of further improving the durability, the modified silicone (a) has one group represented by R’X at one end. That is, in the above formula (1a), s is 0 and t is 1. Examples of the modified silicone (a) include carbinol-modified silicone at both ends (commercially available products include, for example, "X-22-160AS", "KF-6000", "KF-6001", "KF-6002", "KF-6003" (manufactured by Shin-Etsu Chemical Co., Ltd.)), and carbinol-modified silicone at one end (commercially available products include, for example, "X-22-170BX", "X-22-170DX", "X-22-176DX", "X-22-176GX-A" (manufactured by Shin-Etsu Chemical Co., Ltd.)). 1

[0043] ​​ As the modified silicone used in the composite resin B, from the viewpoint of obtaining a toner excellent in hot offset resistance and durability, it may be a modified silicone (b) having an epoxy group at one end or both ends. That is, the modified silicone (b) is Preferably, it is represented by the formula (1b):

[0044]

Chemical formula

[0045]

Chemical formula

[0046] From the viewpoint of further improving durability, the modified silicone (b) preferably has an epoxy group at one end. That is, from the viewpoint of further improving durability, the modified silicone (b) has one group represented by R’X 2 at one end. That is, in the above formula (1b), s is 1 and t is 0. From the viewpoint of further improving hot offset resistance, the modified silicone (b) preferably has an epoxy group at both ends. That is, from the viewpoint of further improving hot offset resistance, the modified silicone (b) has one group represented by R’X 2 at each of both ends. That is, in the above formula (1b), s and t are 1. Examples of the modified silicone (b) include silicone modified with epoxy groups at both ends (commercially available products include "KF-105", "X-22-163A", "X-22-163B", "X-22-163C", "X-22-169AS", "X-22-169B" (manufactured by Shin-Etsu Chemical Co., Ltd.)), and silicone modified with an epoxy group at one end (commercially available products include "X-22-173BX", "X-22-173DX" (manufactured by Shin-Etsu Chemical Co., Ltd.)).

[0047] As the modified silicone used in the composite resin B, from the viewpoint of obtaining a toner excellent in hot offset resistance and durability, it may be a modified silicone (c) having a carboxy group at one or both ends. That is, the modified silicone (c) is preferably of the formula (1c):

[0048]

Chemical formula

[0049]

Chemical formula

[0050] From the viewpoint of further improving the hot offset resistance, the modified silicone (c) preferably has carboxy groups at both ends. That is, from the viewpoint of further improving the hot offset resistance, the modified silicone (c) has one group represented by R’X 3 at each of both ends. That is, in the above formula (1c), s and t are 1. Examples of the modified silicone (c) include carboxy-modified silicone with carboxyl groups at both ends (commercially available products include "X-22-162C" and "BY16-750" (manufactured by Shin-Etsu Chemical Co., Ltd.)), and carboxy-modified silicone with a carboxyl group at one end (commercially available product: "X-22-3710" (manufactured by Shin-Etsu Chemical Co., Ltd.)).

[0051] In the raw materials of the composite resin B, the amount of the modified silicone, from the viewpoint of hot offset resistance, is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, still more preferably 2% by mass or more, still more preferably 2.5% by mass or more, still more preferably 4% by mass or more, and preferably 9% by mass or less, more preferably 7% by mass or less, still more preferably 6% by mass or less, based on the total amount of the raw material monomers including the alcohol component, the carboxylic acid component, the styrene-based compound, and the modified silicone, and the reactive monomers if necessary.

[0052] The above amount is calculated based on the alcohol component, the carboxylic acid component, the raw material monomers and the modified silicone, and the reactive monomers if contained, without considering the amount of water removed by condensation. When the modified silicone has a hydroxy group or a carboxy group, it can be understood as the alcohol component or the carboxylic acid component. However, when the compound having a hydroxy group or a carboxy group contains a silicone skeleton, it is regarded as the modified silicone. For example, when calculating the total amount of the alcohol component and the carboxylic acid component, the modified silicone having a hydroxy group or a carboxy group is not included in these total amounts.

[0053] (Physical properties of composite resin B) From the viewpoint of obtaining excellent hot offset resistance, the number average molecular weight of the composite resin B is preferably 800 or more, more preferably 1,500 or more, still more preferably 2,500 or more, and from the viewpoint of obtaining excellent low-temperature fixing properties, it is preferably 30,000 or less, more preferably 20,000 or less, still more preferably 10,000 or less, still more preferably 5,000 or less, still more preferably 4,000 or less.

[0054] The acid value of the composite resin B is preferably 1 mg KOH / g or more, more preferably 5 mg KOH / g or more, still more preferably 10 mg KOH / g or more, and is preferably 50 mg KOH / g or less, more preferably 35 mg KOH / g or less, still more preferably 25 mg KOH / g or less.

[0055] From the viewpoint of further improving the hot offset resistance and durability, the softening point of the composite resin B is preferably 70°C or higher, more preferably 90°C or higher, still more preferably 100°C or higher, and from the viewpoint of further improving the low-temperature fixing property, it is preferably 140°C or lower, more preferably 130°C or lower, still more preferably 120°C or lower.

[0056] From the viewpoint of further improving the hot offset resistance and durability, the glass transition temperature of the composite resin B is preferably 45°C or higher, more preferably 50°C or higher, still more preferably 55°C or higher, and from the viewpoint of further improving the low-temperature fixing property, it is preferably 80°C or lower, more preferably 70°C or lower, still more preferably 65°C or lower.

[0057] The number average molecular weight, acid value, softening point, and glass transition temperature of the composite resin B can be appropriately adjusted according to the types and amounts of the reaction raw materials used, and the production conditions such as the reaction temperature, reaction time, and cooling rate. Moreover, these values are determined by the methods described in the examples. When two or more types of the composite resin B are used in combination, it is preferable that the values of the number average molecular weight, acid value, hydroxyl value, softening point, and glass transition temperature obtained as their mixture are respectively within the aforementioned ranges.

[0058] The composite resin B is preferably produced by a method including, for example, step A of polycondensing an alcohol component, a carboxylic acid component, and a modified silicone, and step B of addition-polymerizing a raw material monomer of an addition-polymerized resin segment and a bifunctional monomer. Step B may be carried out after step A, step A may be carried out after step B, or step A and step B may be carried out simultaneously. In Project A, a part of the carboxylic acid component is subjected to a polycondensation reaction, and then after carrying out Project B, the remainder of the carboxylic acid component is added to the polymerization system, and it is preferable to further proceed with the polycondensation reaction in Project A and the polycondensation reaction with the carboxy groups possessed by both reactive monomers or the constituent sites derived from both reactive monomers.

[0059] In Project A, if necessary, an esterification catalyst such as tin(II) bis(2-ethylhexanoate), dibutyltin oxide, titanium diisopropoxybis(triethanolaminato) may be used in an amount of 0.01 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass in total of the alcohol component and the carboxylic acid component; an esterification co-catalyst such as gallic acid (the same as 3,4,5-trihydroxybenzoic acid) may be used in an amount of 0.001 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass in total of the alcohol component and the carboxylic acid component for polycondensation. Further, when using a monomer having an unsaturated bond such as fumaric acid for polycondensation, a radical polymerization inhibitor may be used, if necessary, in an amount of preferably 0.001 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass in total of the alcohol component and the carboxylic acid component. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The temperature of the polycondensation reaction is preferably 120°C or higher, more preferably 160°C or higher, still more preferably 180°C or higher, and is preferably 250°C or lower, more preferably 240°C or lower. Note that the polycondensation may be carried out in an inert gas atmosphere.

[0060] Examples of the radical polymerization initiator for the addition polymerization in Project B include peroxides such as dibutyl peroxide, persulfates such as sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile). The amount of the radical polymerization initiator used is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the raw material monomer of the addition polymerization resin segment. The temperature of the addition polymerization is preferably 110°C or higher, more preferably 130°C or higher, and is preferably 230°C or lower, more preferably 220°C or lower, still more preferably 210°C or lower.

[0061] From the viewpoint of further improving hot offset resistance and durability, the content of the composite resin B in the binder resin of the shell portion is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 70% by mass or more, still more preferably 90% by mass or more, and is 100% by mass or less, and more preferably 100% by mass. Also, from the viewpoint of further improving hot offset resistance and durability, the content of the composite resin B in the entire shell portion is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 70% by mass or more, still more preferably 90% by mass or more, and is 100% by mass or less, and more preferably 100% by mass.

[0062] The binder resin forming the core portion of the toner particles is not particularly limited, and examples thereof include polyester resins, vinyl resins such as addition polymerization resins of raw material monomers containing styrene-based compounds, epoxy resins, polycarbonates, polyurethanes, and composite resins containing two or more of these resins. In the present invention, it is preferable to contain an addition polymerization resin of a raw material monomer containing a styrene-based compound (hereinafter also referred to as "resin A"), and further, it is preferable to contain a crystalline polyester resin (hereinafter also referred to as "resin C"). <Addition polymerization resin of raw material monomer containing styrene-based compound (resin A)> Resin A is an addition polymerization resin obtained by subjecting a raw material monomer containing a styrene-based compound to an addition polymerization reaction. Examples of the styrene-based compound include unsubstituted or substituted styrene. Examples of the substituent for styrene include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group, or a salt thereof. Examples of the styrene-based compound include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrene sulfonic acid, or a salt thereof. Among these, styrene is preferable.

[0063] In the raw material monomers of Resin A, the content of the styrene-based compound is preferably 50% by mass or more, more preferably 65% by mass or more, still more preferably 75% by mass or more, and is 100% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less.

[0064] Examples of the raw material monomers other than the styrene-based compound include (meth)acrylic acid esters such as alkyl (meth)acrylate, benzyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate; olefins such as ethylene, propylene, and butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether; vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. Among these, (meth)acrylic acid esters are preferred, and alkyl (meth)acrylate is more preferred. The number of carbon atoms of the alkyl group in the alkyl (meth)acrylate is preferably 1 or more, more preferably 4 or more, still more preferably 6 or more, and is preferably 24 or less, more preferably 22 or less, still more preferably 20 or less. Examples of the (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, (iso)propyl (meth)acrylate, (iso- or tertiary)butyl (meth)acrylate, (iso)amyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, (iso)dodecyl (meth)acrylate, (iso)palmityl (meth)acrylate, (iso)stearyl (meth)acrylate, (iso)behenyl (meth)acrylate, etc. Preferred are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate or stearyl (meth)acrylate, more preferred are n-butyl acrylate, 2-ethylhexyl acrylate, and even more preferred is n-butyl acrylate. Note that “(iso- or tertiary)” and “(iso)” mean both cases where these prefixes are present and cases where they are not present. When these prefixes are not present, it indicates normal. Also, “(meth)acrylic acid” indicates acrylic acid or methacrylic acid.

[0065] In the raw material monomers of Resin A, the content of the (meth)acrylic acid ester is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 35% by mass or less, even more preferably 25% by mass or less. In the raw material monomers of Resin A, the total amount of the styrene-based compound and the (meth)acrylic acid ester is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass.

[0066] Resin A can be produced by subjecting raw material vinyl monomers to an addition polymerization reaction. In the addition polymerization reaction, a radical polymerization initiator and a polymerization inhibitor may be used as necessary. Examples of the radical polymerization initiator and the polymerization inhibitor include the same ones as those that can be used in the production of the composite resin B, and the preferred embodiments are also the same. The temperature of the addition polymerization reaction is preferably 100 °C or higher, more preferably 110 °C or higher, still more preferably 130 °C or higher, and is preferably 250 °C or lower, more preferably 230 °C or lower, still more preferably 210 °C or lower.

[0067] From the viewpoints of hot offset resistance and durability, the softening point of Resin A is preferably 80 °C or higher, more preferably 100 °C or higher, still more preferably 110 °C or higher, and is preferably 150 °C or lower, more preferably 130 °C or lower, still more preferably 120 °C or lower. Resin A is preferably an amorphous resin. From the viewpoints of hot offset resistance and durability, the glass transition temperature of Resin A is preferably 35 °C or higher, more preferably 40 °C or higher, still more preferably 50 °C or higher, and is preferably 80 °C or lower, more preferably 70 °C or lower, still more preferably 60 °C or lower.

[0068] When the binder resin of the core part contains Resin A, the content of Resin A with respect to the total amount of the binder resin of the core part is preferably 40% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, still more preferably 75% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less.

[0069] <Crystalline polyester resin (Resin C)> It is also preferable that the core part of the toner particles contains a crystalline polyester resin (Resin C) in addition to the above-described Resin A. Resin C is, for example, a crystalline polyester resin that is a polycondensate of an alcohol component and a carboxylic acid component. As the alcohol component, α,ω-aliphatic diol is preferred. The number of carbon atoms of the α,ω-aliphatic diol is preferably 2 or more, more preferably 4 or more, still more preferably 6 or more, and preferably 16 or less, more preferably 14 or less, still more preferably 12 or less. Examples of the α,ω-aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol. Among these, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol are preferred, and 1,10-decanediol is more preferred.

[0070] The amount of the α,ω-aliphatic diol is preferably 80 mol% or more, more preferably 85 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more in the alcohol component, and 100 mol% or less, and still more preferably 100 mol%.

[0071] The alcohol component may contain other alcohol components different from the α,ω-aliphatic diol. Examples of the other alcohol components include aliphatic diols other than α,ω-aliphatic diols such as 1,2-propanediol and neopentyl glycol; aromatic diols such as alkylene oxide adducts of bisphenol A; and trihydric or higher alcohols such as glycerin, pentaerythritol, and trimethylolpropane. These alcohol components may be used alone or in combination of two or more.

[0072] As the carboxylic acid component, aliphatic dicarboxylic acid is preferred, and linear aliphatic dicarboxylic acid is more preferred. The number of carbon atoms of the aliphatic dicarboxylic acid is preferably 4 or more, more preferably 8 or more, still more preferably 10 or more, and preferably 14 or less, more preferably 12 or less. Examples of the aliphatic dicarboxylic acid include fumaric acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid. Among these, sebacic acid and tetradecanedioic acid are preferred, and sebacic acid is more preferred. These carboxylic acid components may be used alone or in combination of two or more.

[0073] The amount of the aliphatic dicarboxylic acid is preferably 80 mol% or more, more preferably 85 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more in the carboxylic acid component, and 100 mol% or less, and still more preferably 100 mol%.

[0074] The carboxylic acid component may contain other carboxylic acid components different from the aliphatic dicarboxylic acid. Examples of the other carboxylic acid components include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid; polyvalent carboxylic acids having a trivalent or higher valence. These carboxylic acid components may be used alone or in combination of two or more.

[0075] The equivalent ratio of the carboxy group of the carboxylic acid component to the hydroxyl group of the alcohol component [COOH group / OH group] is preferably 0.7 or more, more preferably 0.8 or more, and preferably 1.3 or less, more preferably 1.2 or less.

[0076] Resin C is produced, for example, by a method of polycondensing an alcohol component and a carboxylic acid component. In the polycondensation, if necessary, the above-described esterification catalyst may be used in the above-described amount, and the above-described esterification cocatalyst may be used in the above-described amount. When using a monomer having an unsaturated bond such as fumaric acid in the polycondensation, the above-described radical polymerization inhibitor may be used in the above-described amount if necessary. The temperature of the polycondensation reaction is preferably 120 °C or higher, more preferably 160 °C or higher, still more preferably 180 °C or higher, and preferably 250 °C or lower, more preferably 240 °C or lower. Note that the polycondensation may be carried out in an inert gas atmosphere.

[0077] (Physical properties of Resin C) From the viewpoint of the hot offset resistance of the toner, the softening point of Resin C is preferably 60 °C or higher, more preferably 70 °C or higher, still more preferably 80 °C or higher, and from the viewpoint of further improving the low-temperature fixing property, it is preferably 150 °C or lower, more preferably 120 °C or lower, still more preferably 100 °C or lower, still more preferably 95 °C or lower. From the viewpoint of the hot offset resistance of the toner, the melting point of Resin C is preferably 50 °C or higher, more preferably 60 °C or higher, still more preferably 70 °C or higher, and from the viewpoint of further improving the low-temperature fixing property, it is preferably 100 °C or lower, more preferably 90 °C or lower, still more preferably 85 °C or lower, still more preferably 80 °C or lower.

[0078] The acid value of Resin C is preferably 5 mgKOH / g or higher, more preferably 10 mgKOH / g or higher, still more preferably 15 mgKOH / g or higher, and preferably 35 mgKOH / g or lower, more preferably 25 mgKOH / g or lower, still more preferably 20 mgKOH / g or lower.

[0079] The softening point, melting point, and acid value of Resin C can be appropriately adjusted according to the type and amount of the raw material monomers used, as well as the manufacturing conditions such as the reaction temperature, reaction time, and cooling rate, and are determined by the method described in the examples below. When using two or more types of crystalline polyester resin C in combination, it is preferable that the values of the softening point, melting point, and acid value obtained as a mixture thereof are within the respective ranges.

[0080] When the binder resin of the core part contains resin A and resin C, the mass ratio of resin A to resin C [resin A / resin C] in the core part is preferably 40 / 60 or more, more preferably 60 / 40 or more, still more preferably 70 / 30 or more, and even more preferably 75 / 25 or more, and is preferably 95 / 5 or less, more preferably 90 / 10 or less, and still more preferably 85 / 15 or less.

[0081] <Amorphous polyester resin> The core part of the toner particles may contain an amorphous polyester resin instead of resin A, or together with resin A and resin C. The amorphous polyester resin is, for example, an amorphous polyester resin containing a polycondensate of an alcohol component and a carboxylic acid component. Examples of the amorphous polyester resin include polyester resins and modified polyester resins. Examples of the modified polyester resin include urethane-modified polyester resins, epoxy-modified polyester resins, and composite resins containing a polyester resin segment and an addition polymer resin segment. Among these, it is preferable that it is an amorphous composite resin containing a polyester resin that is a polycondensate of an alcohol component and a carboxylic acid component, or a polyester resin segment that is a polycondensate of an alcohol component and a carboxylic acid component, and an addition polymer resin segment that is an addition polymer of a raw material monomer containing a styrene-based compound. As the amorphous polyester resin, amorphous resin A described in JP-A-2021-085937 is exemplified.

[0082] <Colorant> In the present embodiment, the toner particles preferably contain a colorant, and it is more preferable that the core part contains a colorant. As the colorant, all dyes, pigments, etc. used as colorants for toners can be used. Examples of the colorant include carbon black, phthalocyanine blue (e.g., Pigment Blue 15:3), Permanent Brown FG, Brilliant Fast Scarlet, Pigment Green B, rhodamine - B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, quinacridone, Carmine 6B, disazo yellow (e.g., Pigment Yellow 155). The toner may be either a black toner or a color toner other than black. The content of the colorant is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 4% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less in the toner particles.

[0083] <Release agent> In this embodiment, it is preferable that the toner particles contain a release agent, and it is more preferable that the core part contains a release agent. Examples of the release agent include polypropylene wax, polyethylene wax, polypropylene - polyethylene copolymer wax; hydrocarbon waxes such as microcrystalline wax, paraffin wax, Fischer - Tropsch wax or their oxides; ester waxes such as carnauba wax, montan wax or their deacidified waxes, fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts. These may be used alone or in combination of two or more. The melting point of the release agent is preferably 60°C or higher, more preferably 65°C or higher, still more preferably 70°C or higher, and preferably 150°C or lower, more preferably 130°C or lower, still more preferably 100°C or lower. When using a combination of two or more release agents, the melting points of the respective waxes are preferably within the aforementioned range.

[0084] The content of the release agent is preferably 0.5% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more in the toner particles, and preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 5% by mass or less.

[0085] In the present embodiment, from the viewpoints of hot offset resistance and durability, the mass of the shell part with respect to 100 parts by mass of the core part is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 8 parts by mass or more, and preferably 30 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less.

[0086] [Method for manufacturing toner] The toner having toner particles with the above core-shell structure is preferably obtained by a method having the following steps 1 to 3. Step 1: A step of aggregating resin particles X containing a binder resin of the core part in an aqueous medium to obtain aggregated particles 1. Step 2: A step of aggregating resin particles Y containing a silicone-modified amorphous composite resin (resin B) with respect to the aggregated particles 1 obtained in Step 1 to obtain aggregated particles 2. Step 3: A step of heating and fusing the aggregated particles 2 obtained in Step 2 to obtain fused particles. In Step 1, in an aqueous medium, resin particles X are aggregated to obtain aggregated particles 1. Here, it is preferable that the resin particles X contain resin A, or contain resin A and resin C, and may further contain an amorphous polyester resin. In addition to the resin particles X, it is preferable to aggregate colorant particles and release agent particles, and it is more preferable to mix a resin particle dispersion liquid containing the resin particles X, a colorant particle dispersion liquid containing the colorant particles, and a release agent particle dispersion liquid containing the release agent particles to aggregate these particles.

[0087] As methods for manufacturing toner particles by Steps 1 to 3, for example, Steps 1, 1', and 2 described in JP-A-2021-012242 and Steps 1, 1', and 2 described in JP-A-2021-026129 are referred to.

[0088] In the above step 1, it is preferable to aggregate coloring agent particles containing a coloring agent and mold release agent particles containing a mold release agent together with the resin particles X. The dispersion of the resin particles X is preferably obtained by the phase inversion emulsification method. The coloring agent particles are preferably contained in the aggregated particles 1 by mixing and aggregating them with the resin particles as a dispersion of the coloring agent particles. The coloring agent particle dispersion is preferably obtained by dispersing a coloring agent and an aqueous medium using a disperser such as a homogenizer or an ultrasonic disperser. From the viewpoint of improving the dispersion stability of the coloring agent, it is preferable to perform the dispersion in the presence of a polymer dispersant or a surfactant. As a method for preparing the coloring agent particle dispersion, for example, the method described in JP-A-2021-085914 is referred to. The mold release agent particles are preferably contained in the aggregated particles by mixing and aggregating them with the resin particle dispersion and the coloring agent dispersion as a dispersion of the mold release agent particles. The dispersion of the mold release agent particles can be obtained using a surfactant, but it is preferable to obtain it by mixing the mold release agent and the resin particles P. By preparing the mold release agent particles using the mold release agent and the resin particles P, the mold release agent particles are stabilized by the resin particles P, and the mold release agent can be dispersed in the aqueous medium without using a surfactant. In the dispersion of the mold release agent particles, it is considered to have a structure in which a large number of resin particles P adhere to the surface of the mold release agent particles. The resin constituting the resin particles P for dispersing the mold release agent is preferably a polyester resin, and it is more preferable to use a composite resin D having a polyester resin segment and an addition polymerization resin segment. For the mold release agent particle dispersion and the composite resin D, JP-A-2021-026129 is referred to. The dispersion of the resin particles Y used in step 2 is preferably obtained by the phase inversion emulsification method. Further, after the above step 3, a post-treatment step may be performed, and it is preferable to obtain toner particles by isolation. Since the particles obtained in step 3 are present in an aqueous medium, it is preferable to first perform solid-liquid separation, then perform washing as necessary, and perform drying.

[0089] [Toner Particles] The toner particles obtained by drying or the like can be used as they are as toner for electrostatic charge image development. However, as described later, it is preferable to use those obtained by treating the surface of the toner particles as toner for electrostatic charge image development. The volume median particle diameter (D 50 ) of the toner particles is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more, and even more preferably 5 μm or more, from the viewpoint of improving the productivity of the toner, and from the viewpoints of the hot offset resistance and durability of the toner. And preferably 10 μm or less, more preferably 8 μm or less, still more preferably 7 μm or less. The CV value of the toner particles is preferably 12% or more, more preferably 16% or more, still more preferably 20% or more, from the viewpoint of improving the productivity of the toner. And from the viewpoint of obtaining a high-quality image, preferably 36% or less, more preferably 34% or less, still more preferably 32% or less. The roundness of the toner particles is preferably 0.955 or more, more preferably 0.960 or more, still more preferably 0.965 or more, from the viewpoints of the hot offset resistance and durability of the toner. And preferably 0.990 or less, more preferably 0.985 or less, still more preferably 0.980 or less.

[0090] [External Additive] The toner particles can be used as they are as toner for electrostatic charge image development. However, it is preferable to use those obtained by adding a fluidizing agent or the like as an external additive to the surface of the toner particles as toner for electrostatic charge image development. Examples of the external additive include inorganic fine particles such as hydrophobic silica, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferable. The external additive may be used alone or in combination of two or more. Also, the same kind of external additive having different particle sizes may be used in combination. When performing surface treatment of toner particles using an external additive, the addition amount of the external additive is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, still more preferably 4 parts by mass or less, based on 100 parts by mass of the toner particles.

[0091] <Electrostatic charge image developing toner> The electrostatic charge image developing toner obtained as described above can be used as a one-component developer or as a two-component developer by mixing with a carrier.

Examples

[0092] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. Physical properties such as those of the resin were measured by the following methods. In the notations such as “alkylene oxide (X)”, the numerical value X in the parentheses means the average number of moles of alkylene oxide added.

[0093] [Measurement method] 〔Acid value of resin〕 The acid value of the resin was measured according to the neutralization titration method described in JIS K 0070:1992. However, chloroform was used as the measurement solvent.

[0094] 〔Softening point, crystallinity index, melting point and glass transition temperature of resin〕 (1) Softening point Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), while heating 1 g of the sample at a heating rate of 6 ° C / min, a load of 1.96 MPa was applied by a plunger, and it was extruded from a nozzle having a diameter of 1 mm and a length of 1 mm. The plunger drop amount of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point. (2) Crystallinity index Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan and cooled to 0 °C at a cooling rate of 10 °C / min. Next, the sample was allowed to stand as it was for 1 minute, and then heated to 180 °C at a heating rate of 10 °C / min to measure the heat quantity. Among the observed endothermic peaks, the temperature of the peak with the largest peak area was taken as the maximum endothermic peak temperature (1), and the crystallinity index was determined by (softening point (°C)) / (maximum endothermic peak temperature (1) (°C)). (3) Melting point and glass transition temperature Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated to 200 °C, and then cooled from that temperature to 0 °C at a cooling rate of 10 °C / min. Next, the sample was heated at a heating rate of 10 °C / min to measure the heat quantity. Among the observed endothermic peaks, the temperature of the peak with the largest peak area was taken as the maximum endothermic peak temperature (2). For the crystalline resin, this peak temperature was taken as the melting point. Also, when a peak was observed in the case of an amorphous resin, the temperature of that peak was taken as the glass transition temperature. When no peak was observed and a step was observed, the temperature at the intersection of the tangent line showing the maximum slope of the curve at the step portion and the extension of the baseline on the low-temperature side of the step was taken as the glass transition temperature.

[0095] [Number-average molecular weight and weight-average molecular weight of Resins A and B, modified silicone, and unmodified silicone] The molecular weight distribution was measured by gel permeation chromatography (GPC) method and the number-average molecular weight and weight-average molecular weight were determined by the following method. (1) Preparation of sample solution The sample was dissolved in tetrahydrofuran at 25 °C so that the concentration became 0.5 g / 100 mL. Next, this solution was filtered using a fluororesin filter "DISMIC-25JP" (manufactured by Advantec Toyo Co., Ltd.) with a pore size of 0.2 μm to remove insoluble components, and a sample solution was obtained. (2) Molecular weight measurement Using the following measuring device and analytical column, flow tetrahydrofuran as the eluent at a flow rate of 1 mL per minute, and stabilize the column in a constant temperature bath at 40°C. Inject 100 μL of the sample solution therein and perform the measurement. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. The calibration curve at this time uses several types of monodisperse polystyrenes "A-500" (5.0×10 2 ), "A-1000" (1.01×10 3 ), "A-2500" (2.63×10 3 ), "A-5000" (5.97×10 3 ), "F-1" (1.02×10 4 ), "F-2" (1.81×10 4 ), "F-4" (3.97×10 4 ), "F-10" (9.64×10 4 ), "F-20" (1.90×10 5 ), "F-40" (4.27×10 5 ), "F-80" (7.06×10 5 ), "F-128" (1.09×10 6 ) (all manufactured by Tosoh Corporation) prepared using them as standard samples. Measuring device: "HLC-8220GPC" (manufactured by Tosoh Corporation) Analytical column: "GMHXL" + "G3000HXL" (both manufactured by Tosoh Corporation)

[0096] 〔Melting point of release agent〕 Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.02 g of the sample into an aluminum pan, heat it up to 200°C, then cool it from 200°C to 0°C at a cooling rate of 10°C / min. Next, heat the sample at a heating rate of 10°C / min and measure the heat quantity, and take the maximum peak temperature of the endotherm as the melting point.

[0097] 〔Volume median diameter D 50 and CV value of resin particles, colorant particles, and release agent particles〕 (1) Measuring device: Laser diffraction particle size analyzer "LA-920" (manufactured by Horiba, Ltd.) (2) Measurement conditions: A sample dispersion was placed in a measurement cell, distilled water was added, and the volume median diameter D 50 and the volume average diameter D v were measured at a concentration that brought the absorbance within an appropriate range. Also, the CV value was calculated according to the following formula. CV value (%) = (standard deviation of particle size distribution / volume average diameter D v ) × 100

[0098] 〔Solid content concentration of resin particle dispersion, colorant particle dispersion, and mold release agent particle dispersion〕 Using an infrared moisture meter "FD - 230" (manufactured by Kett Scientific Co., Ltd.), 5 g of the measurement sample was measured for moisture (mass%) at a drying temperature of 150°C and a measurement mode of 96 (monitoring time 2.5 minutes, fluctuation range of moisture content 0.05%). The solid content concentration was calculated according to the following formula. Solid content concentration (mass%) = 100 - moisture (mass%)

[0099] 〔Volume median diameter D 50 of agglomerated particles〕 The volume median diameter D 50 of the agglomerated particles was measured as follows. · Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) · Aperture diameter: 50 μm · Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.) · Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) · Measurement conditions: By adding the sample dispersion to 100 mL of the above electrolyte, after adjusting the concentration to a level where the particle sizes of 30,000 particles could be measured in 20 seconds, 30,000 particles were measured again, and the volume median diameter D 50 was obtained from the particle size distribution.

[0100] 〔Circularity of fused particles〕 The circularity of the fused particles was measured under the following conditions. · Measuring device: Flow-type particle image analyzer "FPIA - 3000" (manufactured by Sysmex Corporation) · Preparation of dispersion: A dispersion of the fused particles was prepared by diluting with deionized water so that the solid content concentration was 0.001 to 0.05% by mass. · Measurement mode: HPF measurement mode

[0101] 〔Volume median particle diameter D of toner particles 50 and CV value〕 The volume median particle diameter D of the toner particles 50 was measured as follows. The measuring device, aperture diameter, analysis software, and electrolyte were the same as those used in the measurement of the volume median particle diameter D of the aggregated particles described above. 50 · Dispersion: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance) = 13.6) was dissolved in the electrolyte to obtain a dispersion with a concentration of 5% by mass. · Dispersion conditions: 10 mg of the measurement sample of the toner particles after drying was added to 5 mL of the dispersion, and dispersed with an ultrasonic disperser for 1 minute. Then, 25 mL of the electrolyte was added, and further dispersed with an ultrasonic disperser for 1 minute to prepare a sample dispersion. · Measurement conditions: By adding the sample dispersion to 100 mL of the electrolyte, the concentration was adjusted to a concentration at which the particle diameters of 30,000 particles could be measured in 20 seconds. Then, 30,000 particles were measured, and the volume median particle diameter D 50 and the volume average particle diameter D V were determined. Also, the CV value (%) was calculated according to the following formula. CV value (%) = (standard deviation of particle size distribution / volume average particle diameter D V ) × 100

[0102] [Evaluation method] 〔High-temperature fixability (hot offset resistance) of toner〕 Using a high-quality paper "J paper A4 size" (manufactured by Fuji Xerox Co., Ltd.) and a commercially available printer "Microline (registered trademark) 5400" (manufactured by Okidata Corporation), the adhesion amount of the toner on the paper was 0.30 ± 0.01 mg / cm 2The solid image obtained was output without fixing at a length of 50 mm, leaving a margin of 5 mm from the top edge of the A4 paper. Next, an external fuser with variable temperature and rotation speed was used. The temperature of the external fuser was set to 130°C, and the toner was fixed at a speed of 4 seconds per sheet in the vertical direction of A4 to obtain a printed matter. At a fuser temperature of 130°C, it was visually confirmed that no hot offset occurred. In the same manner, the temperature of the fuser was increased by 5°C at a time from 130°C to fix the toner and obtain a printed matter, and the occurrence of hot offset was visually confirmed. This test was carried out until the temperature at which hot offset occurred. Note that hot offset refers to the phenomenon where the viscoelasticity of the toner on the unfixed image decreases or the release property deteriorates at high temperature, resulting in the adhesion of the toner to the fixing roller. The occurrence of hot offset can be judged by whether the toner adheres to the paper again when the fixing roller makes one revolution. In this test, since the circumferential length of the fixing roller is 87 mm, it was judged by whether there is toner adhesion in the portion 87 mm from the top edge of the solid image. The hot offset occurrence temperature refers to the temperature at which hot offset begins to occur. Here, a temperature 5°C lower than the hot offset occurrence temperature was defined as the highest temperature at which hot offset does not occur. Note that in the evaluation of the hot offset occurrence temperature, a difference of 5°C in the evaluation temperature clearly shows a difference in the toner fixability, especially the hot offset resistance.

[0103] 〔Durability of Toner (Time until Appearance of Streaks)〕 Toner was mounted on the ID cartridge of a commercially available printer "Microline (registered trademark) 5400" (manufactured by Okidata Co., Ltd.) equipped with an ID cartridge modified so that the developing roller could be visually observed. Under the conditions of a temperature of 30°C and a relative humidity of 80%, an idle running operation was performed at 70 r / min (equivalent to 36 sheets / min), and the appearance of streaks on the surface of the developing roller was visually observed every 2 hours, and the time until streaks appeared was measured. The time of "the time when streaks appeared - 2 hours" was defined as the streak occurrence time and used as an index of durability. The larger the value, the better the durability. Note that "suzimura" refers to a state in which the amount of toner adhering to the developing roller varies, and due to the occurrence of suzimura, shading occurs in the image density during printing.

[0104] [Manufacture of Resin] [Manufacture of Amorphous Resin A] Production Example A1 (Production of Resin A-1) Into a 10 L four-necked flask equipped with a thermometer, a stainless steel stirring rod, a reflux condenser, a dropping funnel, and a nitrogen inlet tube, 2 L of xylene was placed. Into the dropping funnel, 880 g of styrene, 220 g of n-butyl acrylate, and 100 g of a radical polymerization initiator, dibutyl peroxide, were placed. While stirring under a nitrogen atmosphere, the temperature of the xylene was raised to 135°C, and the mixture in the dropping funnel was added dropwise over 1 hour. Thereafter, the temperature was raised to 200°C, held at 200°C for 2 hours, then the pressure inside the flask was further reduced and held at 8 kPa for 1 hour to remove the xylene and obtain Resin A-1. The physical properties are shown in Table 1.

[0105]

Table 1

[0106] [Manufacture of Amorphous Resin B] Production Example B1 (Resin B-1) The interior of a 10 L four-necked flask equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple was purged with nitrogen. 1,046 g of a propylene oxide (2.2) adduct of bisphenol A, 3,076 g of an ethylene oxide (2.2) adduct of bisphenol A, 1,716 g of terephthalic acid, and 371 g of silicone "X-22-170BX" (manufactured by Shin-Etsu Chemical Co., Ltd.) were placed in the flask. While stirring under a nitrogen atmosphere, the temperature was raised to 160 °C and maintained at 160 °C. A mixture of 1,116 g of styrene, 245 g of 2-ethylhexyl acrylate, 27 g of acrylic acid, and 54 g of dibutyl peroxide was added dropwise over 1 hour. Then, after maintaining at 160 °C for 30 minutes, the temperature was raised to 200 °C, and the pressure inside the flask was further reduced and maintained at 8 kPa for 1 hour. After that, after returning to atmospheric pressure, 30 g of tin(II) bis(2-ethylhexanoate) and 3.0 g of 3,4,5-trihydroxybenzoic acid were added, the temperature was raised to 235 °C, and after maintaining at 235 °C for 8 hours, the pressure inside the flask was reduced and maintained at 8 kPa for 1 hour. After that, after returning to atmospheric pressure, it was cooled to 190 °C, 215 g of trimellitic anhydride was added, the temperature was raised to 210 °C at 10 °C / hr, and then the reaction was carried out at 4 kPa to the desired softening point to obtain Resin B-1. The physical properties are shown in Table 2.

[0107] Production Examples B2 to B4, B81, B82 (Resins B-2 to B-4, Resins B-81, B-82) Resins B-2 to B-4, B-81, and B-82 were obtained in the same manner as in Production Example B1 except that the raw material composition was changed as shown in Table 2. The physical properties are shown in Table 2.

[0108] In Table 2, the various silicones used have the following compositions. · X-22-170BX: Modified silicone oil "X-22-170BX" (silicone having a carbinol group at one end [the silicone (a) described above, where only one end is a group represented by formula (2a-1)]), kinematic viscosity (25 °C) 40 mm 2 / s, number average molecular weight Mn 1,900, weight average molecular weight Mw 3,500, functional group equivalent 2,800 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd.) · KF-6001: Modified silicone oil "KF-6001" (silicone having carbinol groups at both ends [the silicone (a) described above (both ends are groups represented by the formula (2a-1))], kinematic viscosity (25 °C) 45 mm 2 / s, number average molecular weight Mn 1,800, weight average molecular weight Mw 2,700, functional group equivalent 900 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd.) · KF96-100cs: Unmodified silicone oil "KF96-100cs" (silicone oil, kinematic viscosity (25 °C) 100 mm 2 / s, manufactured by Shin-Etsu Chemical Co., Ltd.) Note that the kinematic viscosities and functional group equivalents of the modified silicone and the unmodified silicone were adopted from the catalog values of each product.

[0109]

Table 2

[0110] 〔Production of Crystalline Polyester Resin C〕 Production Example C1 (Production of Resin C-1) The inside of a 10 L four-necked flask equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple was purged with nitrogen, 3,416 g of 1,10-decanediol and 4,084 g of sebacic acid were added, and while stirring, the temperature was raised to 135 °C and held at 135 °C for 3 hours, and then the temperature was raised from 135 °C to 200 °C over 10 hours. Thereafter, 23 g of tin(II) bis(2-ethylhexanoate) was added, and after holding at 200 °C for 1 hour, the pressure inside the flask was reduced, and it was held under a reduced pressure of 8 kPa for 1 hour to obtain a crystalline polyester resin C-1. The physical properties are shown in Table 3.

[0111]

Table 3

[0112] Production Example D1 (Production of Resin D-1) The interior of a 10 L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen. 4,313 g of a propylene oxide (2.2) adduct of 2,2-bis(4-hydroxyphenyl)propane, 818 g of terephthalic acid, 727 g of succinic acid, 30 g of tin(II) bis(2-ethylhexanoate), and 3.0 g of 3,4,5-trihydroxybenzoic acid (gallic acid) were added. While stirring under a nitrogen atmosphere, the temperature was raised to 235 °C and held at 235 °C for 5 hours. Then, the pressure inside the flask was reduced and held at 8 kPa for 1 hour. After that, after returning to atmospheric pressure, it was cooled to 160 °C and held at 160 °C. A mixture of 2,756 g of styrene, 689 g of stearyl methacrylate, 142 g of acrylic acid, and 413 g of dibutyl peroxide was added dropwise over 1 hour. Then, after holding at 160 °C for 30 minutes, the temperature was raised to 200 °C, and the pressure inside the flask was further reduced. The reaction was carried out at 8 kPa until the desired softening point was reached to obtain Resin D-1. The obtained Resin D-1 had a softening point of 91 °C, a glass transition temperature of 42 °C, and a crystallization index of 1.8.

[0113] [Production of resin particle dispersion liquid] Production Example X1 (Production of resin particle dispersion liquid X-1) In a 3 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 160 g of Resin A-1, 40 g of Resin C-1, 110 g of ethyl acetate, and 40 g of a 15 mass% aqueous solution of sodium dodecylbenzenesulfonate "Neoperex G-15" (manufactured by Kao Corporation, an anionic surfactant) were added and dissolved at 70 °C over 2 hours. To the obtained solution, 760 g of deionized water at 70 °C was added, and dispersion treatment was carried out at an output of 350 W for 30 minutes using an ultrasonic homogenizer "UP-400S" (manufactured by Healsher). Then, while maintaining the temperature at 70 °C, ethyl acetate was distilled off under reduced pressure, deionized water was added, and the solid content concentration was adjusted to 20 mass% to obtain resin particle dispersion liquid X-1. The volume median diameter D 50 of the obtained resin particles was 0.24 μm, and the CV value was 30%

[0114] Production Example Y1 (Production of resin particle dispersion liquid Y-1) Into a 3 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 300 g of resin B-1, 300 g of methyl ethyl ketone, and 41 g of deionized water were placed as a mixed solvent, and the resin was dissolved at 73 °C over 2 hours. To the resulting solution, a 5 mass% aqueous sodium hydroxide solution was added to a neutralization degree of 55 mol% with respect to the acid value of the resin, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73 °C and stirring at 280 r / min (peripheral speed 88 m / min), 600 g of deionized water was added over 60 minutes to effect phase inversion emulsification. Subsequently, while maintaining the temperature at 73 °C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, while stirring at 280 r / min (peripheral speed 88 m / min), the aqueous dispersion was cooled to 30 °C, and then deionized water was added so that the solid content concentration became 20 mass% to obtain a resin particle dispersion liquid Y-1. The volume median diameter D 50 and CV value of the obtained resin particles are shown in Table 4.

[0115] Production Examples Y2 to Y4, Y81 to Y82 (Production of Resin Particle Dispersions Y-2 to Y-4, Y-81 to Y-82) Resin particle dispersions Y-2 to Y-4, Y-81 to Y-82 were obtained in the same manner as in Production Example Y1, except that the type of resin used was changed as shown in Table 4. The volume median diameter D 50 and CV value of the obtained resin particles are shown in Table 4.

[0116]

Table 4

[0117] Production Example P1 (Production of Resin Particle Dispersion P-1) Into a 3 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 200 g of resin D-1 and 200 g of methyl ethyl ketone were placed, and the resin was dissolved at 73 °C over 2 hours. To the resulting solution, a 5 mass% aqueous sodium hydroxide solution was added to a neutralization degree of 60 mol% with respect to the acid value of the resin, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C and stirring at 280 r / min (peripheral speed 88 m / min), 700 g of deionized water was added over 50 minutes to cause phase inversion emulsification. Subsequently, while still maintaining the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, while stirring at 280 r / min (peripheral speed 88 m / min), the aqueous dispersion was cooled to 30°C, and then deionized water was added so that the solid content concentration became 20% by mass, thereby obtaining a resin particle dispersion liquid P-1. The volume median diameter D 50 of the obtained resin particles was 0.09 μm, and the CV value was 23%.

[0118] [Production of Release Agent Particle Dispersion Liquid] Production Example W1 (Production of Release Agent Particle Dispersion Liquid W-1) To a beaker with an internal volume of 1 L, 120 g of deionized water, 86 g of resin particle dispersion liquid P-1, and 40 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75°C) were added, and the temperature was maintained at 90 to 95°C to melt and stir to obtain a molten mixture. While maintaining the temperature of the obtained molten mixture at 90 to 95°C, using an ultrasonic homogenizer "US-600T" (manufactured by Nihon Seiki Co., Ltd.), after dispersing for 20 minutes, it was cooled to room temperature (20°C). Deionized water was added to adjust the solid content concentration to 20% by mass to obtain a release agent particle dispersion liquid W-1. The volume median diameter D 50 of the release agent particles in the dispersion liquid was 0.47 μm, and the CV value was 27%.

[0119] [Production of Addition Polymer E] Production Example E1 (Synthesis of Addition Polymer E-1) The raw material monomers of the types and amounts shown in Table 5 were mixed to prepare a monomer mixture liquid with a total monomer amount of 100 g. The interior of a four-necked flask equipped with a nitrogen inlet tube, a dropping funnel, a stirrer, and a thermocouple was purged with nitrogen, and 18 g of methyl ethyl ketone, 0.03 g of 2-mercaptoethanol, and 10% by mass of the monomer mixture were added. The temperature was raised to 75°C while stirring. While maintaining the temperature at 75°C, a mixture of the remaining 90% by mass of the monomer mixture, 0.27 g of 2-mercaptoethanol, 42 g of methyl ethyl ketone, and 3 g of 2,2'-azobis(2,4-dimethylvaleronitrile) "V-65" (manufactured by Fujifilm Wako Pure Chemical Corporation) was added dropwise from the dropping funnel over 3 hours. After completion of the dropwise addition, the mixture was held at 75°C for 2 hours, then a solution prepared by dissolving 3 g of V-65 in 5 g of methyl ethyl ketone was added, and the mixture was further held at 75°C for 2 hours and at 80°C for 2 hours. Thereafter, methyl ethyl ketone was distilled off under reduced pressure to obtain an addition polymer E-1. The weight average molecular weight of the obtained addition polymer is shown in Table 5.

[0120] [Table 5]

[0121] [Production of Colorant Particle Dispersion] Production Example Z1 (Production of Colorant Particle Dispersion Z-1) Into a 5 L container equipped with a stirrer with a dispersing blade, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 75 g of an addition polymer E-1 and 630 g of methyl ethyl ketone were placed, and the resin was dissolved at 20°C. To the resulting solution, 101 g of a 5 mass% aqueous sodium hydroxide solution (the neutralization degree of the addition polymer E-1 becomes 91 mol%) was added, and further 955 g of deionized water was added, and the mixture was stirred at 20°C for 10 minutes with a dispersing blade. Next, 300 g of Pigment Yellow 155 (manufactured by Clariant Chemicals, "Toner Yellow 3GP-CT", molecular weight 717) was added, and the mixture was stirred at 6400 r / min at 20°C for 2 hours with a dispersing blade. Then, it was passed through a 200-mesh filter and treated with 15 passes at a pressure of 150 MPa using a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics). While stirring the resulting dispersion, methyl ethyl ketone and a part of water were removed at 70°C under reduced pressure. After cooling, it was passed through a 200-mesh filter, and deionized water was added so that the solid content concentration became 20 mass% to obtain a colored pigment particle dispersion Z-1. The volume median diameter D 50 of the obtained colored pigment particles was 0.10 μm, and the CV value was 28%.

[0122] [Manufacture of toner] Example 1 (Manufacture of toner 1) Preparation of toner 1 Into a 3 L four-necked flask equipped with a dehydrating tube, a stirring device, and a thermocouple, 500 g of a resin particle dispersion X-1, 21 g of a release agent particle dispersion W-1, 63 g of a colored pigment particle dispersion Z-1, 3.3 g of a 15 mass% aqueous sodium dodecylbenzenesulfonate solution "Neoperex G-15" (manufactured by Kao Corporation, an anionic surfactant) were mixed at a temperature of 25°C. Next, while stirring the mixture, an aqueous solution prepared by dissolving 40 g of ammonium sulfate in 570 g of deionized water and adding a 4.8 mass% aqueous potassium hydroxide solution to adjust the pH to 8.4 was added dropwise at 25°C over 10 minutes, and then the temperature was raised to 57°C over 2 hours, and the volume median diameter D 50 of the aggregated particles was maintained at 57°C until it reached 6.0 μm to obtain a dispersion of aggregated particles (1). While maintaining the temperature of the dispersion of the aggregated particles (1) at 57°C, 60 g of the resin particle dispersion Y-1 was dropped at a rate of 0.6 mL / min to obtain a dispersion of the core-shell particles (1). To the obtained dispersion of the core-shell particles (1), an aqueous solution was added which was a mixture of 25 g of sodium polyoxyethylene lauryl ether sulfate "Emal E-27C" (manufactured by Kao Corporation, an anionic surfactant, effective concentration 27% by mass), 300 g of deionized water, and 40 g of a 0.1 mol / L sulfuric acid aqueous solution. Thereafter, the temperature was raised to 80°C over 1 hour, held at 80°C for 30 minutes, then 15 g of a 0.1 mol / L sulfuric acid aqueous solution was added and held at 80°C for 15 minutes. Thereafter, 15 g of a 0.1 mol / L sulfuric acid aqueous solution was added again, and by holding at 80°C until the circularity became 0.970, a dispersion of the fused particles in which the core-shell particles were fused was obtained. The obtained dispersion of the fused particles was cooled to 30°C, the dispersion was suction-filtered to separate the solid content, then washed with deionized water at 25°C, and suction-filtered at 25°C for 2 hours. Thereafter, using a vacuum isothermal dryer "DRV622DA" (manufactured by ADVANTEC), vacuum drying was performed at 33°C for 24 hours to obtain toner particles. 100 parts by mass of the toner particles, 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., number average particle diameter; 0.04 μm), and 1.0 part by mass of hydrophobic silica "Cab-O-Sil (registered trademark) TS720" (manufactured by Cabot Japan Co., Ltd., number average particle diameter; 0.012 μm) were put into a Henschel mixer and stirred, and passed through a 150-mesh sieve to obtain Toner 1. The obtained toner had a particle diameter of 6.1 μm and a circularity of 0.970.

[0123] Examples 2 to 4 and Comparative Examples 1 to 2 (Production of Toners 2 to 4, 81 to 82) Toners 2 to 4, 81 to 82 were prepared in the same manner as in Example 1 except that the type of the resin particle dispersion used was changed as shown in Table 6. The physical properties of the obtained toner particles and the evaluation results of the toners are shown in Table 6.

[0124]

Table 6

[0125] From the results of Examples 1 to 4 and Comparative Examples 1 and 2 above, it can be seen that according to the present invention, a toner excellent in hot offset resistance and durability can be obtained.

Claims

1. A toner for electrostatic charge image development containing toner particles, wherein the toner particles have a core-shell structure, the shell portion contains a silicone-modified amorphous composite resin containing a polyester resin segment, an addition polymerization resin segment containing a structural unit derived from a styrene-based compound, and a polyorganosiloxane segment, the silicone-modified amorphous composite resin is a reaction product of a reaction raw material containing an alcohol component containing a dihydric or higher alcohol, a carboxylic acid component containing a dicarboxylic acid compound or higher, a raw material monomer containing a styrene-based compound, and a modified silicone having a hydroxy group, a carboxy group, or an epoxy group at one or both ends, A toner for electrostatic charge image development.

2. The modified silicone is represented by the formula (1): 【Chemical Formula 1】 [In the formula, each R is independently a hydrocarbon group having 1 to 6 carbon atoms, each R' is independently an alkylene group having 1 to 10 carbon atoms, each R'' is independently a hydrocarbon group having 1 to 10 carbon atoms, each X is independently a hydroxy group, a hydroxyalkyloxy group, a carboxy group, a carboxyalkyloxy group, an epoxy group, a glycidyl group, a glycidyloxy group, or an alicyclic epoxy group, s is an integer of 1 to 3, t is an integer of 0 to 3, and n is an integer of 5 to 300.] The toner for electrostatic charge image development according to claim 1, containing a modified silicone represented by the formula.

3. The toner for electrostatic charge image development according to claim 1 or 2, wherein the modified silicone has a hydroxy group at one or both ends.

4. The toner for electrostatic charge image development according to any one of claims 1 to 3, wherein the content of the modified silicone is 0.1% by mass or more and 9% by mass or less based on the total amount of the reaction raw materials.

5. The toner for electrostatic charge image development according to any one of claims 1 to 4, wherein the core portion contains an addition polymerization resin of a raw material monomer containing a styrene-based compound.

6. The toner for electrostatic charge image development according to any one of claims 1 to 5, wherein the core portion contains a crystalline polyester resin.

7. A method for producing a toner for electrostatic charge image development according to any one of claims 1 to 6, having the following steps 1 to 3. Step 1: A step of aggregating resin particles X containing a binder resin of a core portion in an aqueous medium to obtain aggregated particles 1. Step 2: A step of aggregating resin particles Y containing a silicone-modified amorphous composite resin with respect to the aggregated particles 1 obtained in Step 1 to obtain aggregated particles 2. Step 3: A step of heating and fusing the agglomerated particles 2 obtained in Step 2 to obtain fused particles

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