Toner and Method for Producing Toner

Abstract

The present invention relates to a toner and a method for producing the toner. The toner contains toner particles, and the toner particles contain a resin component including a crystalline resin and an amorphous resin. In a cross-sectional observation of the toner particles, a domain-matrix structure including a matrix containing the crystalline resin and domains containing the amorphous resin is observed. The maximum endothermic peak temperature Tm of the toner measured by DSC is 50°C to 80°C. When the storage elastic modulus of the toner at a temperature 5°C lower than Tm is G'(−5) (Pa) and the storage elastic modulus of the toner at a temperature 5°C higher than Tm is G'(+5) (Pa), G'(−5) and G'(+5) satisfy the inequality (1): G'(−5) / G'(+5) ≥ 50 ··· (1), and when the maximum loss tangent of the toner in the temperature range of 50°C to 130°C is tanδ(Max), tanδ(Max) satisfies the inequality (2): 0.0 ≤ tanδ(Max) ≤ 1.50 ··· (2).

Description

Technical Field

[0001] The present disclosure relates to a toner for an electrophotographic image forming apparatus. Background Art

[0002] Recently, there has been an increasing demand for energy saving measures in electrophotographic image forming apparatuses. As such energy saving measures, techniques for fixing a toner at a low temperature to reduce power consumption during a fixing process have been studied.

[0003] In order to improve the low-temperature fixability of a toner, for example, the glass transition point of a binder resin of the toner can be lowered. However, since lowering the glass transition point of the binder resin results in a decrease in the heat-resistant storage stability of the toner, it is difficult to simultaneously achieve the low-temperature fixability and the heat-resistant storage stability of the toner by this method.

[0004] Therefore, studies have been made on using a crystalline resin for a toner to simultaneously achieve the low-temperature fixability and the heat-resistant storage stability of the toner. An amorphous resin that is usually used as a binder resin for a toner does not show a distinct endothermic peak in differential scanning calorimetry (DSC) measurement. In contrast, a crystalline resin shows an endothermic peak in DSC. Due to the regular arrangement of alkyl groups within or between molecules, the crystalline resin has a property of hardly softening until it reaches its melting point. With this property, the crystalline resin undergoes a sharp melting (rapid melting) of crystals when it reaches the melting point, and undergoes a sharp decrease in viscosity accompanying this.

[0005] As a material having high rapid melting property and providing a toner having both low-temperature fixability and heat-resistant storage stability, a crystalline vinyl resin is known. The crystalline vinyl resin is a vinyl-based polymer containing monomer units having long-chain alkyl groups. That is, the crystalline vinyl resin has a main-chain skeleton and side-chain long-chain alkyl groups. As a result of crystallization caused by the regular arrangement of the side-chain long-chain alkyl groups, the resin shows crystallinity.

[0006] Japanese Patent Application Laid-Open No. 2014-130243 proposes a toner containing a side-chain crystalline resin, that is, a crystalline vinyl resin as a core for the purpose of improving low-temperature fixability.

[0007] However, the present inventors have conducted in-depth studies on the toner disclosed in Japanese Patent Application Laid-Open No. 2014-130243 and found that the toner may sometimes contaminate a fixing device. Summary of the Invention

[0008] At least one aspect of the present disclosure relates to providing a toner that can have high low-temperature fixability and is less likely to contaminate a fixing device.

[0009] According to one aspect of the present disclosure, there is provided a toner containing toner particles, the toner particles containing a resin component including a crystalline resin and an amorphous resin. In a cross-sectional observation of the toner particles, a domain-matrix structure including a matrix containing the crystalline resin and domains containing the amorphous resin is observed. The maximum endothermic peak temperature Tm (°C) of the toner measured by a differential scanning calorimeter (DSC) is from 50°C to 80°C. G'(-5) and G'(+5) satisfy the inequality (1): G'(-5) / G'(+5) ≥ 50 ··· (1), where G'(-5) (Pa) is the storage elastic modulus of the toner at a temperature 5°C lower than Tm (°C), and G'(+5) (Pa) is the storage elastic modulus of the toner at a temperature 5°C higher than Tm (°C). Tanδ(Max) satisfies the inequality (2): 0.0 ≤ tanδ(Max) ≤ 1.50 ··· (2), where tanδ(Max) is the maximum loss tangent of the toner in the temperature range from 50°C to 130°C.

[0010] According to the present disclosure, there can be provided a toner that can have high low-temperature fixability and is less likely to contaminate a fixing device.

[0011] Further features of the present disclosure will become apparent from the description of the following exemplary embodiments. Detailed Description

[0012] Unless otherwise specified, the phrases "XX or more and YY or less" and "XX to YY" indicating a numerical range each mean a numerical range including its endpoints (i.e., the lower limit and the upper limit).

[0013] The term "(meth)acrylate" means acrylate and / or methacrylate, and the term "(meth)acrylic acid" means acrylic acid and / or methacrylic acid.

[0014] When numerically ranging is described in segments, the upper limit of each numerical range can be combined with the lower limit of any other numerical range.

[0015] The term "monomer unit" means a unit constituting a polymer and refers to the reaction form of a monomer (polymerizable monomer). For example, a part from one carbon-carbon bond to another carbon-carbon bond in the main chain of a polymer composed of polymerized vinyl-based monomers is one monomer unit. The vinyl-based monomer can be represented by the following formula (Z), and the vinyl-based monomer unit is a structural unit of the polymer or the reaction form of the monomer represented by the formula (Z). The monomer unit can also be abbreviated as "unit".

[0016]

[0017] (In the formula (Z), R Z1 represents a hydrogen atom or an alkyl group, and RZ2 represents a substituent.)

[0018] The term "crystalline resin" refers to a resin that shows a distinct endothermic peak in differential scanning calorimeter (DSC) measurement using the resin, toner particles, or toner as a measurement sample (differential scanning calorimeter is also referred to as DSC).

[0019] In the cross-sectional observation of toner particles, the part containing crystalline resin refers to the part determined to be 127 gray levels or less by image analysis of the cross-section of the toner stained with ruthenium as described below. In the image analysis, the brightness change from black to white is represented by 0 gray level to 255 gray levels. Similarly, the part containing non-crystalline resin refers to the part at 128 gray levels or more. That is, when performing binarization in which the part at 127 gray levels or less is converted to black and the part at 128 gray levels or more is converted to white, the part mainly composed of crystalline resin is the part represented by black, and the part mainly composed of non-crystalline resin is the part represented by white.

[0020] The present inventors have conducted in-depth research and found that toners having the above-described constituent features tend to be toners that can have high low-temperature fixability and are less likely to contaminate the fixing device. The presumed mechanism and constituent features will be described in detail below.

[0021] Mechanism for producing the advantageous effects of the present disclosure

[0022] The present inventors presume the mechanism for producing the advantageous effects of the present disclosure as follows.

[0023] When a matrix containing crystalline resin is observed in the cross-sectional observation of toner particles, it means that the physical properties of the toner are likely to depend on the crystalline resin and provide high low-temperature fixability. When a domain containing non-crystalline resin is observed, the non-crystalline resin easily provides high elasticity without impairing the low-temperature fixability provided by the crystalline resin, and thus the toner tends to be less likely to contaminate the fixing device.

[0024] When the maximum endothermic peak temperature Tm of the toner measured by DSC is in a sufficiently low temperature range of 50°C to 80°C, the resin contained in the toner is easily plasticized at low temperatures and provides high low-temperature fixability. When the ratio of the storage elastic modulus at a temperature 5°C lower than the endothermic peak temperature to the storage elastic modulus at a temperature 5°C higher than the endothermic peak temperature is 50.0 or more, the toner melts rapidly at or near the endothermic peak temperature, and thus the toner has high low-temperature fixability.

[0025] In addition, when the maximum loss tangent tanδ(Max) of the toner is 1.50 or less in the range of 50°C to 130°C, the viscosity of the toner will not be too high in this temperature range, so the toner is less likely to contaminate the fixing device.

[0026] Domain-matrix structure

[0027] In the cross-sectional observation of the toner particles, a domain-matrix structure including a matrix containing a crystalline resin and a domain containing an amorphous resin was observed.

[0028] Due to the presence of the crystalline resin in the matrix, the physical properties of the toner are likely to depend on the crystalline resin, so the toner tends to have improved crystallinity and high low-temperature fixability. Due to the presence of the amorphous resin in the domain, high elasticity is provided without impairing the low-temperature fixability of the toner, so the toner tends to have high heat-resistant stain resistance and durability and is less likely to contaminate the fixing device.

[0029] Preferably, a domain-matrix structure including a matrix mainly composed of a crystalline resin and a domain mainly composed of an amorphous resin was observed.

[0030] In the present disclosure, in a manner similar to the method using the binary image described above, it is determined whether the matrix and the domain each contain a crystalline resin or an amorphous resin and whether the matrix and the domain are each composed of a crystalline resin or an amorphous resin.

[0031] The domain-matrix structure as described above can be obtained by controlling the quantitative ratio and viscosity ratio of the crystalline resin and the amorphous resin used for producing the toner.

[0032] The domain-matrix structure as described above can be obtained by controlling the quantitative ratio and viscosity ratio of the crystalline resin and the amorphous resin used for producing the resin component.

[0033] The domain according to the present disclosure means a domain having a domain size of 0.001 μm or more.

[0034] Maximum endothermic peak temperature (Tm)

[0035] In the present disclosure, the maximum endothermic peak temperature Tm (°C) of the toner measured by DSC is 50°C to 80°C. For example, by introducing the vinyl-based polymer A described later into the toner, the maximum endothermic peak temperature Tm within this range can be achieved.

[0036] The maximum endothermic peak of the toner measured by DSC means the endothermic peak of the component that absorbs and melts the most in the toner, that is, the endothermic peak of the component that contributes the most to the melting of the toner.

[0037] When Tm is 50 °C or higher, it means that the melting temperature of the component that contributes most to the melting of the toner is not too low, and the resin component of the toner is not easily plasticized until the temperature at which melting starts is reached, thereby providing high heat-resistant storage stability. For this reason, Tm is 50 °C or higher, preferably 55 °C or higher. When Tm is 80 °C or lower, it means that the component that contributes most to the melting of the toner melts at a sufficiently low temperature, and the resin component of the toner is easily plasticized due to melting, thereby providing high low-temperature fixability. For this reason, Tm is 80 °C or lower, preferably 75 °C or lower.

[0038] The maximum endothermic peak is preferably an endothermic peak attributed to the melting of the resin component.

[0039] Storage elastic modulus (G'(-5) and G'(+5))

[0040] The toner of the present disclosure is a toner in which G'(-5) and G'(+5) satisfy the inequality (1): G'(-5) / G'(+5) ≥ 50 ··· (1), where G'(-5) (Pa) is the storage elastic modulus of the toner at a temperature 5 °C lower than Tm (°C), and G'(+5) (Pa) is the storage elastic modulus of the toner at a temperature 5 °C higher than Tm (°C). When the inequality (1) is satisfied, the toner melts rapidly at or near Tm and tends to have high low-temperature fixability. Therefore, it is preferable to satisfy the inequality (1). The toner more preferably satisfies the formula (5): G'(-5) / G'(+5) ≥ 150 ··· (5).

[0041] For the upper limit, it is preferable to satisfy the following inequality (8).

[0042] G'(-5) / G'(+5) ≤ 2000 ··· (8)

[0043] G'(+5) is preferably 1.00×10 4 to 1.00×10 6 Pa. When G'(+5) is within this range, both high low-temperature fixability and heat-resistant storage stability can be achieved. Tm, G'(-5), and G'(+5) can be controlled by selecting the composition, content, etc. of the crystalline resin used for the production of the toner.

[0044] A toner that satisfies the above inequalities (1), (5), and (8) can be obtained, for example, by introducing the vinyl-based polymer A described later into the toner.

[0045] Loss tangent (tanδ)

[0046] The toner of the present disclosure satisfies 0.0 ≤ tanδ(Max) ≤ 1.50, where tanδ(Max) is the maximum loss tangent of the toner in the temperature range of 50°C to 130°C. The loss tangent (tanδ) of the toner is the value of the loss elastic modulus / storage elastic modulus of the toner and represents the amount of energy dissipated as heat when stress is applied to the toner and the toner is deformed. Therefore, the higher the frictional resistance generated at the interface between the above domain and the matrix, the more heat energy is dissipated due to this frictional resistance when stress is applied, resulting in a higher loss elastic modulus and a higher loss tangent. It is known that the toner behaves more elastically when it has a lower tanδ and more viscously when it has a higher tanδ, which means that the higher the tanδ of the toner, the higher the viscosity of the toner, and the more likely the toner is to contaminate the fixing device. The present inventors have conducted in-depth research and found that if the value of tanδ(Max) is 0.0 to 1.50 in the temperature range of 50°C to 130°C, then in this temperature range, the toner maintains sufficient elasticity and the viscosity does not become too large, so the toner is less likely to contaminate the fixing device. More preferably, the toner satisfies 0.0 ≤ tanδ(Max) ≤ 0.98. The value of tanδ(Max) can be controlled by selecting the composition and amount of the crystalline resin used for the production of the toner or by selecting the mixing ratio of the crystalline resin and the non-crystalline resin, the type and amount of the radical initiator, etc. in the production of the resin component.

[0047] The mechanism for controlling the loss tangent (tanδ) and the resulting effects are speculated as follows. When a domain-matrix structure is formed in the toner particles, a frictional resistance is generated at the interface between the domain and the matrix. As the polarity difference between the two increases, the frictional resistance at the interface increases, which increases the loss elastic modulus of the toner. The increase in the loss elastic modulus of the toner increases tanδ, thereby increasing the viscosity of the toner. As a result, the toner is very likely to contaminate the fixing device. That is, the control of the affinity at the interface between the domain and the matrix enables the control of the frictional resistance, the loss elastic modulus, and tanδ, so the toner is less likely to contaminate the fixing device.

[0048] Controlling the affinity at the interface between the domain and the matrix to control the loss tangent within the above range can be achieved, for example, by introducing a monomer unit B having a highly polar and highly acidic proton into the vinyl-based polymer A described below.

[0049] Resin component

[0050] The resin component includes a crystalline resin and an amorphous resin. Due to the presence of the crystalline resin in the resin component, the toner tends to have high low-temperature fixability. Due to the presence of the amorphous resin, it is easy to provide high elasticity, and the toner tends to be less likely to contaminate the fixing device. That is, the resin component includes a crystalline resin and an amorphous resin.

[0051] The resin component in the present disclosure is preferably a binder resin. That is, the toner preferably includes toner particles containing a binder resin including a crystalline resin and an amorphous resin.

[0052] The resin component is preferably a resin produced by mixing a crystalline resin and an amorphous resin. More preferably, the resin component is a resin produced by mixing a crystalline vinyl-based resin and an amorphous polyester.

[0053] Preferably, the resin component contains a tetrahydrofuran-soluble substance, and the tetrahydrofuran-soluble substance contains a crystalline resin. When the resin component contains a crystalline resin soluble in tetrahydrofuran (hereinafter also referred to as THF), the elasticity of the toner will not be too high, and it is easy to provide high low-temperature fixability and high heat-resistant stain resistance. The crystalline resin soluble in THF can be introduced into the resin component of the toner by using a crystalline resin in resin production. In order to easily control the elasticity of the toner, the THF-soluble substance can contain an amorphous resin.

[0054] The crystalline resin contained in the THF-soluble substance can be a single crystalline resin or a combination of two or more crystalline resins.

[0055] Vinyl-based polymer A and monomer unit A

[0056] The crystalline resin is preferably a vinyl-based polymer A containing monomer unit A represented by the following formula (A). When the toner contains vinyl-based polymer A, it is easy to achieve both high low-temperature fixability and heat-resistant storage stability. This is probably because the gathering of long-chain alkyl groups represented by R 2 helps to provide a resin component with high crystallinity. In order to introduce vinyl-based polymer A into the toner, the crystalline resin used for resin production is preferably vinyl-based polymer A. Vinyl-based polymer A is preferably a resin soluble in THF.

[0057]

[0058] (In formula (A), R 1 represents H or CH3, and R 2 represents an alkyl group having 18 to 36 carbon atoms.)

[0059] The vinyl polymer A containing monomer unit A can be introduced as a monomer unit of the vinyl polymer A by vinyl polymerization using a (meth)acrylate containing an alkyl group having 18 to 36 carbon atoms as a polymerizable monomer (hereinafter also referred to as polymerizable monomer A).

[0060] The polymerizable monomer A is a (meth)acrylate containing a linear hydrocarbon group having 18 to 36 carbon atoms.

[0061] Examples of the linear hydrocarbon group having 18 to 36 carbon atoms include a linear unsaturated hydrocarbon group having 18 to 36 carbon atoms and a linear saturated hydrocarbon group having 18 to 36 carbon atoms (hereinafter the linear saturated hydrocarbon group is also referred to as an alkyl group). The (meth)acrylate containing a linear hydrocarbon group having 18 to 36 carbon atoms is preferably a (meth)acrylate containing an alkyl group having 18 to 36 carbon atoms.

[0062] Examples of the (meth)acrylate containing an alkyl group having 18 to 36 carbon atoms include (meth)acrylates containing a linear alkyl group having 18 to 36 carbon atoms [e.g., octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, hexacosyl (meth)acrylate, montanyl (meth)acrylate, melissyl (meth)acrylate, and dotriacontyl (meth)acrylate] and (meth)acrylates containing a branched alkyl group having 18 to 36 carbon atoms [e.g., 2-decyltetradecyl (meth)acrylate].[[]END]]

[0063] Among them, from the viewpoints of improving the storage stability, low-temperature fixability, and high-temperature stain resistance of the toner, (meth)acrylates containing an alkyl group having 18 to 34 carbon atoms are preferred, and (meth)acrylates containing an alkyl group having 18 to 30 carbon atoms are more preferred. Even more preferred is at least one selected from the group consisting of stearyl (meth)acrylate, octadecyl (meth)acrylate, and behenyl (meth)acrylate.

[0064] In the above formula (A), R 2 is preferably an alkyl group having 18 to 34 carbon atoms, more preferably an alkyl group having 18 to 30 carbon atoms, and even more preferably an alkyl group having 18 or 22 carbon atoms. R 2 is preferably a linear alkyl group. R 1 is preferably hydrogen.

[0065] The polymerizable monomer A can be a single polymerizable monomer A or a combination of two or more polymerizable monomers A. The monomer unit A can be a single monomer unit A or a combination of two or more monomer units A.

[0066] In order for the toner to have both low-temperature fixability and heat-resistant storage stability and be less likely to contaminate the fixing device, the content of monomer unit A is preferably 30.0% by mass to 99.9% by mass relative to the content of vinyl-based polymer A.

[0067] When the content of monomer unit A in vinyl-based polymer A is 30.0% by mass or more, it is easy for monomer unit A to aggregate (form into a block) to provide a crystalline portion, thereby improving the crystallinity of vinyl-based polymer A. Therefore, the content of monomer unit A in vinyl-based polymer A is preferably 30.0% by mass or more, more preferably 40.0% by mass or more, still more preferably 45.0% by mass or more. When the content of monomer unit A in vinyl-based polymer A is 99.9% by mass or less, the crystallinity of the matrix in the domain-matrix structure is less likely to be too large, and the frictional resistance generated at the interface between the domain and the matrix is less likely to be high. As a result, the value of tanδ(Max) is less likely to be high, and the toner is less likely to contaminate the fixing device. Therefore, the content of monomer unit A in vinyl-based polymer A is preferably 99.9% by mass or less, more preferably 85.0% by mass or less, still more preferably 75.0% by mass or less.

[0068] When vinyl-based polymer A contains two or more types of monomer unit A, the content of monomer unit A in vinyl-based polymer A refers to its total content.

[0069] The content of vinyl-based polymer A is preferably 20.0% by mass to 95.0% by mass relative to the content of the resin component. When the content of vinyl-based polymer A in the resin component is 20.0% by mass or more, it means that the resin component contains a sufficient amount of vinyl-based polymer A, and it is easy to achieve both low-temperature fixability and heat-resistant storage stability. Therefore, the content of vinyl-based polymer A in the resin component is preferably 20.0% by mass or more, more preferably 30.0% by mass or more. When the content of vinyl-based polymer A in the resin component is 95.0% by mass or less, the crystallinity of the matrix in the domain-matrix structure is less likely to be too large, and the frictional resistance generated at the interface between the domain and the matrix is less likely to be high. As a result, the value of tanδ(Max) is less likely to be high, and the toner is less likely to contaminate the fixing device. Therefore, the content of vinyl-based polymer A in the resin component is preferably 95.0% by mass or less, more preferably 80.0% by mass or less.

[0070] Monomer unit B

[0071] The vinyl-based polymer A preferably further contains a monomer unit B having at least one selected from the group consisting of a carboxyl group and a sulfo group. When the monomer unit B having at least one of the above functional groups is included, it is easy to aggregate (form a block) the monomer units A to provide a crystalline portion, thereby increasing the crystallinity of the vinyl-based polymer A. As a result, it is easy to achieve both high low-temperature fixability and heat-resistant storage stability. In addition, the presence of the monomer unit B will likely make the toner less likely to contaminate the fixing device. The speculative mechanism thereof will be described below.

[0072] Since the vinyl-based polymer A is a crystalline polymer, it is included in the matrix of the domain-matrix structure. Due to the presence of a functional group having a highly polar and highly acidic proton in the monomer unit B, the portion of the vinyl-based polymer A in the matrix where the monomer unit B is present tends to exist near the interface between the matrix and the domain by electrostatic interaction. In addition, the highly acidic proton of the monomer unit B tends to be close to the domain having a relatively high polarity to exist at the interface between the domain and the matrix, thereby improving the affinity at the interface. This tends to result in a reduction in the frictional resistance at the interface and a decrease in the value of tanδ(Max), thereby reducing the possibility of contaminating the fixing device.

[0073] The vinyl-based polymer A containing the monomer unit B can be introduced as a monomer unit of the vinyl-based polymer A by vinyl polymerization using a corresponding polymerizable monomer (hereinafter also referred to as polymerizable monomer B).

[0074] Specific examples of the polymerizable monomer B having a carboxyl group include acrylic acid, aconitic acid, atropic acid, allylmalonic acid, angelic acid, isocrotonic acid, itaconic acid, 10-undecenoic acid, elaidic acid, erucic acid, oleic acid, o-carboxycinnamic acid, crotonic acid, chloroacrylic acid, chloroisocrotonic acid, chlorocrotonic acid, chlorofumaric acid, chloromaleic acid, cinnamic acid, cyclohexenedicarboxylic acid, citraconic acid, hydroxycinnamic acid, dihydroxycinnamic acid, tiglic acid, nitro cinnamic acid, vinylacetic acid, phenylcinnamic acid, 4-phenyl-3-butenoic acid, ferulic acid, fumaric acid, brasileic acid, 2-(2-furyl)acrylic acid, bromocinnamic acid, bromofumaric acid, bromomaleic acid, benzylidenemalonic acid, benzoylacrylic acid, 4-pentenoic acid, maleic acid, mesaconic acid, methacrylic acid, methylcinnamic acid, and methoxycinnamic acid. Among them, acrylic acid, methacrylic acid, maleic acid, fumaric acid, etc. are more preferred for the ease of reaction.

[0075] Specific examples of the polymerizable monomer having a sulfo group include styrenesulfonic acid, vinylsulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid.

[0076] The content of monomer unit B is preferably 0.5% by mass to 30.0% by mass relative to the content of vinyl-based polymer A. When the content of monomer unit B in vinyl-based polymer A is 0.5% by mass or more, it is easy to achieve the above effects, that is, high low-temperature fixability and heat-resistant storage stability, and the toner is less likely to contaminate the fixing device. Therefore, the content of monomer unit B in vinyl-based polymer A is preferably 0.5% by mass or more, more preferably 0.8% by mass or more, still more preferably 1.0% by mass or more. When the content of monomer unit B in vinyl-based polymer A is 30.0% by mass or less, the crystallinity of vinyl-based polymer A is less likely to decrease, and it is easy to achieve both low-temperature fixability and heat-resistant storage stability. Therefore, the content of monomer unit B in vinyl-based polymer A is preferably 30.0% by mass or less, more preferably 25.0% by mass or less, still more preferably 10.0% by mass or less.

[0077] The molecular weight of polymerizable monomer B is preferably 1000 or less. The molecular weight of polymerizable monomer B can be measured using known techniques such as mass spectrometry.

[0078] When the solubility parameter (SP) value of the non-crystalline resin used for producing the resin component is SP P (J / cm 3 ) 0.5 and the SP value of monomer unit B is SP B (J / cm 3 ) 0.5 it is preferably to satisfy the following inequality (4).

[0079] |SP P -SP B |≤5.0···(4)

[0080] When the above inequality (4) is satisfied, the polarity difference between the non-crystalline resin used for producing the resin component and vinyl-based polymer A tends to be kept appropriate, and the toner is less likely to contaminate the fixing device. There is no particular limitation on the lower limit. That is, the lower limit is preferably 0.0 or more. The inventors speculate the mechanism for these effects as follows.

[0081] When the above inequality (4) is satisfied, among the monomer units constituting vinyl-based polymer A, monomer unit B having a high SP value tends to have a higher affinity for the non-crystalline resin compared to monomer units having a low SP value such as monomer unit A. Since the domain contains the non-crystalline resin, monomer unit B constituting a part of vinyl-based polymer A tends to exist near the interface between the domain and the matrix, and the high acidic protons of monomer unit B tend to reduce the frictional resistance generated at the interface. As a result, the toner tends to have a low loss elastic modulus and is less likely to contaminate the fixing device.

[0082] Monomer unit C

[0083] The vinyl polymer A preferably further contains at least one monomer unit C selected from the group consisting of the monomer unit represented by the following formula (B) and the monomer unit represented by the following formula (C). When the vinyl polymer A contains the monomer unit C, the toner tends to have improved elasticity and is less likely to contaminate the fixing device.

[0084]

[0085] (In formula (C), R 13 represents H or CH3.)

[0086] The vinyl polymer A containing the monomer unit C can be introduced as a monomer unit of the vinyl polymer A by vinyl polymerization using the corresponding polymerizable monomer (hereinafter also referred to as polymerizable monomer C).

[0087] Examples of the polymerizable monomer C include styrene, methyl methacrylate, and methyl acrylate.

[0088] Among these polymerizable monomers C, styrene is preferred from the viewpoints of low-temperature fixability, heat-resistant storage stability, and less likelihood of contaminating the fixing device. That is, the monomer unit C is preferably the monomer unit represented by the above formula (B).

[0089] The content of the monomer unit C is preferably 10.0% by mass to 40.0% by mass relative to the content of the vinyl polymer A. When the content of the monomer unit C in the vinyl polymer A is 10.0% by mass or more, the toner tends to have improved elasticity and is therefore less likely to contaminate the fixing device, and the toner tends to have high heat-resistant stain resistance. Therefore, the content of the monomer unit C in the vinyl polymer A is preferably 10.0% by mass or more, more preferably 15.0% by mass or more. When the content of the monomer unit C in the vinyl polymer A is 40.0% by mass or less, the crystallinity of the vinyl polymer A is less likely to decrease, and it is easy to achieve both low-temperature fixability and heat-resistant storage stability. Therefore, the content of the monomer unit C in the vinyl polymer A is preferably 40.0% by mass or less, more preferably 30.0% by mass or less.

[0090] Monomer unit D

[0091] In order to be less likely to contaminate the fixing device and to easily provide low-temperature fixability and heat-resistant storage stability, the vinyl-based polymer A can be a polymer further containing monomer units derived from the polymerizable monomer D given below (hereinafter, when the polymerizable monomer D is used as a monomer unit constituting the vinyl-based polymer A, the monomer unit is also referred to as monomer unit D). Since the polarity of the polymerizable monomer D given below is somewhat different from the polarity of the polymerizable monomer A, the monomer units A tend to aggregate in the vinyl-based polymer A, and the crystallinity of the vinyl-based polymer A tends to increase. As a result, it is easy to provide high low-temperature fixability and high heat-resistant storage stability. In addition, when the vinyl-based polymer A is a polymer having monomer units derived from the polymerizable monomer D, it is easy to control the glass transition temperature and elasticity of the vinyl-based polymer A, and the toner is less likely to contaminate the fixing device.

[0092] The polymerizable monomer D given below can be used, and the polymerizable monomer D has a polymerizable unsaturated group. These polymerizable monomers D can be used alone or in combinations of two or more.

[0093] Polymerizable monomers D having a cyano group, such as acrylonitrile and methacrylonitrile.

[0094] Polymerizable monomers D having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

[0095] Polymerizable monomers D having an amide bond, such as acrylamide and monomers obtained by reacting an amine having 1 to 30 carbon atoms with a carboxylic acid having an ethylenically unsaturated bond and 2 to 30 carbon atoms (e.g., acrylic acid and methacrylic acid) in any known manner.

[0096] Polymerizable monomer D having a urethane bond, for example, obtained by reacting an alcohol having an ethylenically unsaturated bond and 2 to 22 carbon atoms (e.g., 2-hydroxyethyl methacrylate and vinyl alcohol) with an isocyanate having 1 to 30 carbon atoms [e.g., a monoisocyanate compound (e.g., benzenesulfonyl isocyanate, toluenesulfonyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, butyl isocyanate, hexyl isocyanate, tert-butyl isocyanate, cyclohexyl isocyanate, octyl isocyanate, 2-ethylhexyl isocyanate, dodecyl isocyanate, adamantyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,5-dimethylphenyl isocyanate, and 2,6-dipropylphenyl isocyanate), an aliphatic diisocyanate compound (e.g., trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate), an alicyclic diisocyanate compound (e.g., 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated benzene dimethylene diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated tetramethylbenzene dimethylene diisocyanate), and an aromatic diisocyanate compound (e.g., phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and benzene dimethylene diisocyanate)] in any known manner; and a monomer obtained by reacting an alcohol having 1 to 26 carbon atoms (e.g., methanol, ethanol, propanol, isopropanol, butanol, tert-butanol, pentanol, heptanol, octanol, 2-ethylhexanol, nonanol, decanol, undecanol, lauryl alcohol, dodecanol, myristyl alcohol, pentadecanol, cetyl alcohol, heptadecanol, stearyl alcohol, isostearyl alcohol, trans-oleyl alcohol, oleyl alcohol, linoleyl alcohol, linolenyl alcohol, nonadecanol, heneicosanol, behenyl alcohol, and brassidyl alcohol) with an isocyanate having an ethylenically unsaturated bond and 2 to 30 carbon atoms [e.g., 2-isocyanatoethyl (meth)acrylate, 2-([0-(1'-methylpropylideneamino)carbonylamino]ethyl (meth)acrylate, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate, and 1,1-bis((meth)acryloxymethyl)ethyl isocyanate)] in any known manner.

[0097] Polymerizable monomer D having a urea bond, for example, a monomer obtained by reacting an amine having 3 to 22 carbon atoms [for example, a primary amine (for example, n-butylamine, tert-butylamine, propylamine, and isopropylamine), a secondary amine (for example, di-n-ethylamine, di-n-propylamine, and di-n-butylamine), aniline, and an epoxy amine] with an isocyanate having an ethylenically unsaturated bond and 2 to 30 carbon atoms in any known manner.

[0098] Vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl decanoate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl pivalate, and vinyl octanoate are also suitable as polymerizable monomer D.

[0099] Vinyl esters, which are non-conjugated monomers and tend to appropriately maintain reactivity with the first polymerizable monomer, easily increase the crystallinity of the crystalline portion of polymer A and contribute to achieving both low-temperature fixability and heat-resistant storage stability.

[0100] The monomer unit D can be, for example, at least one monomer unit selected from the group consisting of the monomer unit represented by the following formula (D) and the monomer unit represented by the following formula (E).

[0101]

[0102] (In formula (D) and formula (E), X represents a single bond or an alkylene group having 1 to 6 carbon atoms, R 4 represents a cyano group (-C≡N), -C(=O)NHR 7 (where R 7 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), a hydroxyl group, -COOR 8 (where R 8 is an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms) or a hydroxyalkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms)), -NHCOOR 9 (where R 9 is an alkyl group having 1 to 4 carbon atoms), -NH-C(=O)-NH(R 10 )2 (where each R 10 is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms)), -COO(CH2)2NHCOOR 11 (where R 11 is an alkyl group having 1 to 4 carbon atoms), or -COO(CH2)2-NH-C(=O)-NH(R 12 )2 (where each R 12 is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms)), R 6represents an alkyl group having 1 to 4 carbon atoms, and R 3 and R 5 each independently represents a hydrogen atom or CH3). More preferably, the polymerizable monomer D is at least one selected from the group consisting of acrylonitrile and methacrylonitrile. That is, the monomer unit D is more preferably a monomer unit represented by the above formula (D), where R3 is a hydrogen atom or CH3, X is a single bond, and R4 is a cyano group.

[0103] The molecular weight of the polymerizable monomer D is preferably 1000 or less. The molecular weight of the polymerizable monomer D can be measured using known techniques such as mass spectrometry.

[0104] The content of the monomer unit D relative to the content of the vinyl-based polymer A is preferably 1.0% by mass to 20.0% by mass. When the content of the monomer unit D in the vinyl-based polymer A is 1.0% by mass or more, the elasticity of the vinyl-based polymer A is less likely to decrease, thereby reducing the possibility of contaminating the fixing device. In addition, it is easy to cause the monomer unit A to aggregate (form a block) to provide a crystalline portion, thereby providing high low-temperature fixability and heat-resistant storage stability. Therefore, the content of the monomer unit D in the vinyl-based polymer A is preferably 1.0% by mass or more, more preferably 10.0% by mass or more. When the content of the monomer unit D in the vinyl-based polymer A is 20.0% by mass or less, the crystallinity of the vinyl-based polymer A is less likely to decrease, and it is easy to achieve both low-temperature fixability and heat-resistant storage stability. Therefore, the content of the monomer unit D in the vinyl-based polymer A is preferably 20.0% by mass or less, more preferably 15.0% by mass or less.

[0105] The vinyl-based polymer A can be produced, for example, by carrying out vinyl polymerization of a monomer composition containing the polymerizable monomers A, B, C, and D. The vinyl-based polymer A can be synthesized by a solution polymerization method involving reacting the polymerizable monomers with a radical reaction initiator in a solvent (e.g., toluene).

[0106] Amorphous polyester

[0107] The amorphous resin used for production is preferably an amorphous polyester. The polyester is a condensate of an alcohol component and a carboxylic acid component.

[0108] Examples of the alcohol component of the amorphous polyester include the following polyol components.

[0109] Epoxyalkane adducts of bisphenol A, ethylene glycol, diethylene glycol, triethylene glycol, 1,2 - propanediol, 1,3 - propanediol, 1,4 - butanediol, neopentyl glycol, 1,4 - butenediol, 1,5 - pentanediol, 1,6 - hexanediol, 1,4 - cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3,6 - hexanetetraol, 1,4 - anhydro - sorbitol, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4 - butanetriol, 1,2,5 - pentanetriol, glycerol, 2 - methyl - glycerol, 2 - methyl - 1,2,4 - butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5 - trihydroxymethylbenzene.

[0110] Examples of the carboxylic acid component of the non - crystalline polyester include the following unsaturated carboxylic acids and saturated carboxylic acids. Examples of the unsaturated carboxylic acids include unsaturated monocarboxylic acids, unsaturated dicarboxylic acids, unsaturated polycarboxylic acids, their acid anhydrides, and their lower alkyl esters.

[0111] Examples of the unsaturated monocarboxylic acids include unsaturated monocarboxylic acids having 2 to 80 carbon atoms, and specific examples include acrylic acid, methacrylic acid, propiolic acid, 2 - butenoic acid, crotonic acid, isocrotonic acid, 3 - butenoic acid, angelic acid, tiglic acid, 4 - pentenoic acid, 2 - ethyl - 2 - butenoic acid, 10 - undecenoic acid, 2,4 - hexadienoic acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, isolenic acid, gadoleic acid, erucic acid, and nervonic acid.

[0112] Examples of the unsaturated dicarboxylic acids include ethylenedicarboxylic acids having 4 to 50 carbon atoms, and specific examples include alkenyl succinic acids such as dodecenyl succinic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and pentenedioic acid.

[0113] Examples of the unsaturated polycarboxylic acids include vinyl polymers of unsaturated carboxylic acids (number - average molecular weight Mn measured by gel permeation chromatography (GPC): 450 to 10000).

[0114] Among the above - mentioned unsaturated carboxylic acids, acrylic acid, methacrylic acid, alkenyl succinic acids such as dodecenyl succinic acid, maleic acid, fumaric acid, and their combinations are preferred to achieve both low - temperature fixability and high - temperature stain resistance. Acrylic acid, methacrylic acid, maleic acid, fumaric acid, and their combinations are more preferred. Acid anhydrides and lower alkyl esters of these unsaturated carboxylic acids can also be used.

[0115] Examples of the above saturated carboxylic acids include aliphatic carboxylic acids having 2 to 50 carbon atoms (e.g., stearic acid and behenic acid), aromatic carboxylic acids having 7 to 37 carbon atoms (e.g., benzoic acid), alkanedicarboxylic acids having 2 to 50 carbon atoms (e.g., oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, and sebacic acid), aromatic dicarboxylic acids having 8 to 86 carbon atoms (e.g., phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid), aromatic polycarboxylic acids having 9 to 20 carbon atoms (e.g., trimellitic acid and pyromellitic acid), and aliphatic tricarboxylic acids having 6 to 36 carbon atoms (e.g., hexanetricarboxylic acid).

[0116] Acid anhydrides and lower (C1 to C4) alkyl esters (e.g., methyl ester, ethyl ester, and isopropyl ester) of the above saturated carboxylic acids can also be used.

[0117] Among the above saturated carboxylic acids, aromatic carboxylic acids having 7 to 87 carbon atoms, alkanedicarboxylic acids having 2 to 50 carbon atoms, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and aromatic polycarboxylic acids having 9 to 20 carbon atoms are preferred. When using the above saturated carboxylic acids, it is easy to provide high low-temperature fixability, high-temperature stain resistance, and heat storage stability. From the viewpoints of heat storage stability and chargeability, benzoic acid, adipic acid, alkyl succinic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, and combinations thereof are more preferred. Adipic acid, terephthalic acid, trimellitic acid, and combinations thereof are even more preferred. Acid anhydrides and lower alkyl esters of these acids can also be used.

[0118] The crystalline resin and the non-crystalline resin used for production may not be combined with each other or may be partially combined, and in order to easily form a domain-matrix structure having a low interfacial frictional resistance and to easily control tanδ(Max), they are preferably partially combined with each other. For these purposes, the non-crystalline resin preferably has a carbon-carbon double bond. When the crystalline resin and the non-crystalline resin are partially combined with each other, a resin that is not easily mixed with the crystalline resin is introduced into the resin component, and the above domain-matrix structure is easily formed. In addition, the resin tends to be compatible with both the domain and the matrix of the above domain-matrix structure. This helps to reduce the frictional resistance at the interface between the domain and the matrix, thereby reducing the possibility of contaminating the fixing device.

[0119] The polyester having a carbon-carbon double bond can be produced by any method. It is preferably obtained by polycondensation of constituent components including one or more unsaturated carboxylic acid components and / or unsaturated alcohol components.

[0120] A non-linear and non-crystalline polyester can be produced, for example, by carrying out polycondensation of an unsaturated carboxylic acid component and / or an unsaturated alcohol component with a polyol component of three or more components which is otherwise a saturated alcohol component. A non-linear and non-crystalline polyester can also be produced by carrying out polycondensation of a component including a polycarboxylic acid component of three or more components which is a saturated carboxylic acid component.

[0121] The polycondensation reaction of the alcohol component and the carboxylic acid component is carried out in an atmosphere of an inert gas (e.g., nitrogen) at a reaction temperature preferably of 150°C to 280°C, more preferably 160°C to 250°C, still more preferably 170°C to 235°C. When the polycondensation reaction is carried out at a reaction temperature within this range, the constituent components can react sufficiently together. For the polycondensation reaction to proceed reliably, the reaction time is preferably 30 minutes or more, more preferably 2 to 40 hours.

[0122] In addition, an esterification catalyst can be used as needed.

[0123] Examples of the esterification catalyst include tin-containing catalysts (e.g., dibutyltin oxide), antimony dioxide, titanium-containing catalysts (e.g., titanium alkoxides, potassium oxalate titanate, titanium terephthalate, alkoxy titanium terephthalate, dihydroxy bis(triethanolamine) titanium, monohydroxy tris(triethanolamine) titanium, titanyl bis(triethanolaminate), its intramolecular condensate, tributoxy titanium terephthalate, triisopropoxy titanium terephthalate, and diisopropoxy titanium di-terephthalate), zirconium-containing catalysts (e.g., zirconyl acetate), and zinc acetate.

[0124] Among them, the titanium-containing catalyst is preferred. It is also effective to reduce the pressure to increase the reaction rate at the end stage of the reaction.

[0125] A stabilizer can be added for the purpose of providing polymerization stability. Examples of the stabilizer include hydroquinone, methyl hydroquinone, and hindered phenol compounds.

[0126] THF-insoluble matter

[0127] The resin component preferably contains tetrahydrofuran-insoluble matter (THF-insoluble matter). Generally, a resin insoluble in THF has higher elasticity than a resin soluble in THF, and thus tends to provide a toner having a reduced loss tangent and less likely to contaminate the fixing device. Examples of the resin insoluble in THF include resins having a crosslinked structure. The content of the THF-insoluble matter is preferably 5.0% by mass to 80.0% by mass relative to the content of the resin component. When the content of the THF-insoluble matter in the resin component is 5.0% by mass or more, the toner tends to have increased elasticity, and thus has a low tanδ(Max) and is less likely to contaminate the fixing device. Therefore, the content of the THF-insoluble matter in the resin component is preferably 5.0% by mass or more, more preferably 20.0% by mass or more, still more preferably 30.0% by mass or more. When the content of the THF-insoluble matter in the resin component is 80.0% by mass or less, the crystallinity of the toner is less likely to decrease, and the elasticity of the toner is less likely to be excessive, thereby providing high low-temperature fixability and durability. Therefore, the content of the THF-insoluble matter in the resin component is preferably 80.0% by mass or less, more preferably 70.0% by mass or less, still more preferably 67.0% by mass or less.

[0128] The THF-insoluble matter preferably contains a crosslinked resin in which a crystalline resin and an amorphous resin are bonded together. The presence of such a crosslinked resin helps to provide a toner having high low-temperature fixability and less likely to contaminate the fixing device (hereinafter, the crystalline resin used for production is referred to as crystalline resin A, the amorphous resin used for production is referred to as amorphous resin B, and the resin in which crystalline resin A and amorphous resin B are bonded together is referred to as crosslinked resin L). Crystalline resin A and amorphous resin B can be bonded together, for example, by adding a radical initiator to a dissolved or molten mixture of crystalline resin A and amorphous resin B or using a crosslinking agent having functional groups that react with both crystalline resin A and amorphous resin B.

[0129] Examples of the radical initiator used in the crosslinking using a radical initiator include, but are not limited to, inorganic peroxides, organic peroxides, and azo compounds. These radical reaction initiators can be used in combination.

[0130] When both the crystalline resin A and the amorphous resin B have carbon-carbon unsaturated bonds, the carbon-carbon unsaturated bonds are cleaved and the crystalline resin A and the amorphous resin B are crosslinked together. Even if one or both of the crystalline resin A and the amorphous resin B do not have carbon-carbon unsaturated bonds, hydrogen atoms bonded to carbon atoms contained in the crystalline resin A and / or the amorphous resin B are abstracted and the crystalline resin A and the amorphous resin B are crosslinked together. In this case, the radical initiator used is more preferably an organic peroxide having high reactivity in radical reactions.

[0131] There is no particular limitation on the crosslinking agent having functional groups reactive with both the crystalline resin A and the amorphous resin B, and known crosslinking agents can be used. Examples include crosslinking agents having an epoxy group, crosslinking agents having an isocyanate group, crosslinking agents having an oxazoline group, crosslinking agents having a carbodiimide group, crosslinking agents having a hydrazide group, and crosslinking agents having an aziridine group.

[0132] In the crosslinking using a crosslinking agent having functional groups reactive with both the crystalline resin A and the amorphous resin B, both the crystalline resin A and the amorphous resin B need to have functional groups reactive with the crosslinking agent.

[0133] A toner can be produced using a resin in which the crystalline resin A and the amorphous resin B crosslinked by the above method are at least partially bonded together (i.e., a crosslinked resin L in which the crystalline resin A and the amorphous resin B are crosslinked).

[0134] When producing a toner by melt-kneading, toner particles containing a resin in which the crystalline resin A and the amorphous resin B are bonded together can also be produced by melt-kneading a raw material mixture containing the crystalline resin A and the amorphous resin B in the presence of the above radical initiator or crosslinking agent.

[0135] The content of the crosslinked resin L can be controlled by selecting the composition and molecular weight of the crystalline resin A and the amorphous resin B and the degree of bonding between the crystalline resin A and the amorphous resin B during the production of the resin components. The degree of bonding can be controlled by selecting, for example, the type and amount of the above radical reaction initiator and the carbon-carbon double bond content of the amorphous resin B during the production of the resin components.

[0136] For example, the crosslinked resin L is preferably a resin obtained by the following method: a crosslinking reaction is carried out by adding a radical reaction initiator while melt-kneading an amorphous polyester resin having a carbon-carbon double bond used as the amorphous resin B and a vinyl-based polymer A used as the crystalline resin A.

[0137] Crosslinked resin L is produced by using crystalline resin A and amorphous resin B, and crystalline resin A and amorphous resin B are at least partially bonded together to form crosslinked resin L.

[0138] Examples of free radical reaction initiators for crosslinking reactions include, but are not limited to, inorganic peroxides, organic peroxides, and azo compounds. These free radical reaction initiators can be used in combination.

[0139] Examples of inorganic peroxides include, but are not limited to, hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.

[0140] Examples of organic peroxides include, but are not limited to, benzoyl peroxide, di-tert-butyl peroxide, tert-butyl cumyl peroxide, dicumyl peroxide, α,α-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, di-tert-hexyl peroxide, 2,5-dimethyl-2,5-di-tert-butyl peroxyhexanoate, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluoyl peroxide, tert-butyl isobutyrate peroxide, tert-butyl neodecanoate peroxide, cumyl neodecanoate peroxide, tert-butyl 2-ethylhexanoate peroxide, tert-butyl 3,5,5-trimethylhexanoate peroxide, tert-butyl laurate peroxide, tert-butyl benzoate peroxide, tert-butyl isopropyl monocarbonate peroxide, and tert-butyl acetate peroxide.

[0141] Examples of azo compounds or diazo compounds include, but are not limited to, 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile.

[0142] Among them, organic peroxides are preferred because they have high initiator efficiency and do not produce toxic by-products such as cyanides. In addition, reaction initiators with high hydrogen abstraction ability are more preferred because the crosslinking reaction proceeds efficiently with a small amount of reaction initiator. Examples include free radical reaction initiators such as tert-butyl isopropyl monocarbonate peroxide, benzoyl peroxide, di-tert-butyl peroxide, tert-butyl cumyl peroxide, dicumyl peroxide, α,α-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and di-tert-hexyl peroxide.

[0143] In the crosslinking by adding a radical initiator to a dissolved or molten mixture of a crystalline resin A and an amorphous resin B, the addition amount of the radical initiator is preferably 2.0 parts by mass or more based on 100.0 parts by mass of the total amount of the resin components to be crosslinked. When the addition amount of the radical initiator is 2.0 parts by mass or more, the crosslinking reaction between the crystalline resin A and the amorphous resin B is promoted. Therefore, the addition amount of the radical initiator is preferably 2.0 parts by mass or more, more preferably 3.0 parts by mass or more, still more preferably 3.5 parts by mass or more. The upper limit is 50.0 parts by mass.

[0144] Since the crystalline resin A is preferably a vinyl-based polymer A and the crosslinked resin L can be produced by the crosslinking reaction between the crystalline resin A and the amorphous resin B, the crosslinked resin L preferably contains the monomer unit A. Like the vinyl-based polymer A, the presence of the monomer unit A helps to provide high low-temperature fixability and heat-resistant storage stability. In addition to the monomer unit A, the crosslinked resin L preferably further contains the monomer unit B. The presence of the monomer unit A in the crosslinked resin L increases the possibility of being included in the matrix, and like the vinyl-based polymer A, the presence of the monomer unit B reduces the possibility of contaminating the fixing device.

[0145] The THF-insoluble matter preferably has a distinct endothermic peak in DSC. This means that the THF-insoluble matter shows crystallinity. In this case, the toner tends to have high low-temperature fixability because the resin contained in the toner is easily plasticized. Such a THF-insoluble matter can be obtained, for example, by crosslinking a resin including a crystalline resin.

[0146] The mixing ratio of the crystalline resin A to the amorphous resin B (crystalline resin A / amorphous resin B) is preferably 40 / 60 to 95 / 5 by mass fraction. Within this range, when a domain-matrix structure is formed, the matrix sufficiently contains the crystalline resin A, and thus it is easy to provide high low-temperature fixability. In addition, the value of tanδ(Max) tends to satisfy the above inequality (2), and the toner is less likely to contaminate the fixing device. Therefore, the mixing ratio is preferably 40 / 60 to 95 / 5 by mass fraction, more preferably 50 / 50 to 80 / 20 by mass fraction.

[0147] Various additives

[0148] In addition to the binder resin, the toner may optionally contain one or more known additives selected from colorants, release agents, magnetic materials, charge control agents, fluidizing agents, and the like. Materials other than the binder resin used in the toner will be specifically described.

[0149] Release agent

[0150] In order to provide releasability during fixing, a release agent can be introduced into the toner. Examples of the release agent include polyolefin copolymers, polyolefin waxes, such as aliphatic hydrocarbon waxes like microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and ester waxes.

[0151] The molecular weight of the release agent is preferably 1000 or more. When the molecular weight is 1000 or more, the compatibility with the crystalline portion in the toner is low. Therefore, the release agent tends to exude on the surface of the toner particles during fixing, thereby improving the releasability. In addition, since the crystalline portion and the release agent are incompatible with each other, the crystallinity of the crystalline portion tends to increase.

[0152] Here, the molecular weight of the release agent refers to the peak molecular weight (Mp) measured by gel permeation chromatography (GPC). The measurement method will be described later.

[0153] The molecular weight of the release agent is preferably 1500 or more. There is no particular limitation on the upper limit, but in order to ensure the releasability, the upper limit is preferably 10000 or less, more preferably 5000 or less.

[0154] Any release agent with a molecular weight of 1000 or more can be used. Examples include the following substances.

[0155] Aliphatic hydrocarbon waxes, such as low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight olefin copolymers, Fischer-Tropsch wax, and waxes obtained by oxidation or acid addition of these waxes.

[0156] Ester waxes mainly composed of fatty acid esters can also be used. From the viewpoint of molecular weight, the ester wax is preferably an ester wax having three or more functional groups, more preferably an ester wax having four or more functional groups.

[0157] The ester wax having three or more functional groups can be obtained, for example, by condensation of an acid having three or more functional groups with a long-chain straight-chain saturated alcohol or synthesis of an alcohol having three or more functional groups with a long-chain straight-chain saturated fatty acid.

[0158] Examples of the alcohol having three or more functional groups that can be used to obtain the ester wax include the following substances, but are not limited thereto. A mixture of two or more ester waxes can also be used.

[0159] Examples include glycerol, trimethylolpropane, erythritol, pentaerythritol, sorbitol, and their condensates. Examples of the condensates include glycerol condensates, that is, so-called polyglycerols, such as diglycerol, triglycerol, tetraglycerol, hexaglycerol, and decaglycerol; trimethylolpropane condensates, such as di(trimethylol)propane and tri(trimethylol)propane; and pentaerythritol condensates, such as dipentaerythritol and tripentaerythritol.

[0160] Among them, a branched structure is preferred, pentaerythritol and dipentaerythritol are more preferred, and dipentaerythritol is particularly preferred.

[0161] Suitable long-chain straight-chain saturated fatty acids are those represented by the general formula C n H 2n+1 COOH, where n is 5 or more and 28 or less.

[0162] Examples of long-chain straight-chain saturated fatty acids include, but are not limited to, caproic acid, caprylic acid, octylic acid, pelargonic acid, capric acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, behenic acid, and mixtures thereof. From the viewpoint of the melting point of the wax, myristic acid, palmitic acid, stearic acid, and behenic acid are preferred.

[0163] Examples of trifunctional or higher acids include, but are not limited to, trimellitic acid, butanetetracarboxylic acid, and mixtures thereof.

[0164] Suitable long-chain straight-chain saturated alcohols are those represented by C n H 2n+1 OH, where n is 5 or more and 28 or less.

[0165] Examples of long-chain straight-chain saturated alcohols include, but are not limited to, octanol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, and mixtures thereof. From the viewpoint of the melting point of the wax, myristyl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol are preferred.

[0166] The mold release agent preferably has a softening point of 50°C to 170°C as measured using a flow tester. Examples of such mold release agents include polyolefin waxes, natural waxes, aliphatic alcohols having 30 to 50 carbon atoms, fatty acids having 30 to 50 carbon atoms, and mixtures thereof.

[0167] Examples of polyolefin waxes include (co)polymers of olefins (e.g., ethylene, propylene, 1-butene, isobutene, 1-hexene, 1-dodecene, 1-octadecene, and mixtures thereof) [including products obtained by (co)polymerization and thermally degraded polyolefins]; oxides of (co)polymers of olefins having oxygen and / or ozone; maleic acid-modified products of (co)polymers of olefins [e.g., products modified with maleic acid and its derivatives (e.g., maleic anhydride, monomethyl maleate, monobutyl maleate, and dimethyl maleate)]; copolymers of olefins and unsaturated carboxylic acids [e.g., (meth)acrylic acid, itaconic acid, and maleic anhydride] and / or unsaturated carboxylic acid alkyl esters [e.g., (meth)acrylic acid alkyl (C1 to C18 alkyl) esters and maleic acid alkyl (C1 to C18 alkyl) esters]; and Sasol Wax.

[0168] Examples of natural waxes include carnauba wax, montan wax, paraffin wax, and rice bran wax. Examples of aliphatic alcohols having 30 to 50 carbon atoms include triacontanol. Examples of fatty acids having 30 to 50 carbon atoms include triacontanoic acid.

[0169] Preferably, the release agent contains an aliphatic hydrocarbon wax. More preferably, the release agent is an aliphatic hydrocarbon wax. The aliphatic hydrocarbon wax has a low polarity and thus tends to exude from the polymer A during fixing.

[0170] The content of the release agent in the toner is preferably from 1.0% by mass to 30.0% by mass, more preferably from 2.0% by mass to 25.0% by mass. When the content of the release agent in the toner is within this range, it is easy to ensure the releasability during fixing. When the content of the release agent in the toner is 1.0% by mass or more, the toner has good releasability. When the content of the release agent in the toner is 30.0% by mass or less, the release agent is not likely to be exposed on the surface of the toner, resulting in good heat-resistant storage stability.

[0171] The melting point of the release agent is preferably from 80°C to 120°C. When the melting point of the release agent is within this range, the release agent tends to melt during fixing and exude on the surface of the toner particles, and thus tends to exhibit releasability. The melting point of the release agent is more preferably 85°C or higher and 110°C or lower. When the melting point is 80°C or higher, the release agent is not likely to be exposed on the surface of the toner particles, providing good heat-resistant storage stability. When the melting point is 120°C or lower, the release agent melts moderately during fixing, providing good low-temperature fixability and good stain resistance.

[0172] Magnetic material

[0173] Examples of the magnetic material include the following substances.

[0174] Examples include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; alloys of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, bismuth, calcium, manganese, titanium, tungsten, and vanadium; and mixtures thereof.

[0175] Colorant

[0176] Examples of the colorant will be described below.

[0177] Examples of available black colorants include carbon black, grafted carbon, and colorants formulated as black using the yellow / magenta / cyan colorants shown below. Examples of yellow colorants include, for example, compounds such as condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo-metal complexes, methylene compounds, and allylamide compounds. Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Examples of cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds. These colorants can be used alone, as a mixture, and in addition, in a solid solution state.

[0178] Charge control agent

[0179] A charge control agent can be used for improving and stabilizing the chargeability. The charge control agent is preferably an organometallic complex or chelate in which an acid group or a hydroxyl group and a central metal easily interact with each other. Examples thereof include monoazo metal complexes; acetylacetone metal complexes; and metal complexes and metal salts of aromatic hydroxycarboxylic acids or aromatic dicarboxylic acids.

[0180] Fluidizing agent

[0181] Examples of fluidizing agents include colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder.

[0182] Method for producing toner

[0183] There is no particular limitation on the method for producing toner. For example, known production methods such as a pulverization method, a suspension polymerization method, a dissolution suspension method, an emulsion aggregation method, or a dispersion polymerization method can be used. Among them, from the viewpoints of high-temperature stain resistance and less likelihood of contaminating the fixing device, the pulverization method that can provide higher dispersibility is preferred. That is, the method for producing toner preferably includes a step of obtaining a kneaded product by melt-kneading a mixture containing a crystalline resin and an amorphous resin, and a step of obtaining a pulverized product by pulverizing the kneaded product.

[0184] As described above, from the viewpoints of low-temperature fixability, heat-resistant storage stability, and less likelihood of contaminating the fixing device, the method for producing toner of the present disclosure more preferably includes a step of obtaining a kneaded product by melt-kneading a mixture containing a vinyl-based polymer A having crystallinity and an amorphous resin, and a step of obtaining a pulverized product by pulverizing the kneaded product, wherein the vinyl-based polymer A contains a monomer unit A represented by the above formula (A) and a monomer unit B having at least one selected from the group consisting of a carboxyl group and a sulfo group, and SP P and SP BSatisfy the above inequality (4), where SP P (J / cm 3 ) 0.5 is the SP value of the non-crystalline resin, and SP B (J / cm 3 ) 0.5 is the SP value of the monomer unit B.

[0185] In order to be less likely to contaminate the fixing device and to easily provide high low-temperature fixability and heat-resistant storage stability, the step of obtaining the kneaded product is preferably a step of obtaining the kneaded product by melt-kneading a mixture containing a crystalline resin, a non-crystalline resin, and a radical initiator.

[0186] In the case of production by a pulverization method, (i) a mixer such as a Henschel mixer or a ball mill is used to sufficiently mix a binder resin as a constituent component of the toner, magnetic iron oxide particles used as a colorant, and optionally wax, other additives, etc., (ii) a hot kneader such as a twin-screw kneading extruder, a heating roll, a kneader, or an extruder is used to melt-knead the obtained mixture so that wax, a colorant, etc. are dispersed or dissolved in mutually compatible resins, and (iii) after curing by cooling, pulverization and classification are carried out, whereby toner particles can be obtained.

[0187] In order to control the shape and surface properties of the toner, the method preferably has a surface treatment step of passing the pulverized or classified product through a surface treatment device that continuously applies mechanical impact force after pulverization or classification. By controlling the time of the surface treatment step, the surface shape of the toner can be controlled, and the adhesion of the toner can be controlled.

[0188] Furthermore, as needed, a mixer such as a Henschel mixer is used to sufficiently mix desired external additives, whereby toner can be obtained.

[0189] Examples of the mixer include the following: Henschel mixer (manufactured by Nippon Coke & Engineering Co., Ltd.); Super mixer (manufactured by Kawata Mfg. Co., Ltd.); Ribocone (manufactured by Okawara Mfg. Co., Ltd.); Nauta mixer, Turbulizer, and Cyclomix (manufactured by Hosokawa Micron Corporation); Helical pin mixer (manufactured by Pacific Machinery & Engineering Co., Ltd.); and Loedige mixer (manufactured by Matsubo Corporation).

[0190] Examples of kneaders include the following: KRC kneader (manufactured by Kurimoto, Ltd.); Buss Ko-kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by Japan Steel Works, LTD.); PCM kneader (manufactured by Ikegai Corporation); three-roll mill, mixing roll mill, and kneader (manufactured by Inoue Mfg., Inc.); Kneadex (manufactured by Mitsui Mining Co., Ltd.); MS type pressure kneader and kneader-Ruder (manufactured by Nihon Spindle Manufacturing Co., Ltd.); and Banbury mixer (manufactured by Kobe Steel, Ltd.).

[0191] Examples of grinders include the following: Counter Jet Mill, MicronJet, and Inomizer (manufactured by Hosokawa Micron Corporation); IDS type grinder and PJM jet mill (manufactured by Nippon Pneumatic MFG. Co., Ltd.); cross jet mill (manufactured by Kurimoto, Ltd.); Ulmax (manufactured by Nisso Engineering Co., Ltd.); SK Jet-O-Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); turbo grinder (manufactured by Turbo Corporation); and super rotor (manufactured by Nisshin Engineering Inc.).

[0192] Examples of classifiers include the following: Classiel, Micron classifier, and Spedic classifier (manufactured by Seishin Enterprise Co., Ltd.); Turbine classifier (manufactured by Nisshin Engineering Inc.); Micron separator, Turboplex (ATP), and TSP separator (manufactured by Hosokawa Micron Corporation); Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.); Dispersion separator (manufactured by Nippon Pneumatic Mfg. Co., Ltd.); and YM Micro Cut (manufactured by Yasukawa Shoji Co., Ltd.).

[0193] Examples of surface modification equipment include Faculty (manufactured by Hosokawa Micron Corporation), Mechano Fusion (manufactured by Hosokawa Micron Corporation), Nobilta (manufactured by Hosokawa Micron Corporation), Hybridizer (manufactured by Nara Machinery Co., Ltd.), Inomizer (manufactured by Hosokawa Micron Corporation), Theta Composer (manufactured by Tokuju Co., Ltd.), and Mechanomill (manufactured by Okada Seiko Co., Ltd.).

[0194] Examples of screening equipment for screening coarse particles include the following: Ultrasonic (manufactured by Koeisangyo Co., Ltd.); Resona sieve and Gyro sieve (manufactured by Tokuju Co., Ltd.); Vibrasonic system (manufactured by Dalton Corporation); Soniclean (manufactured by Sintokogio, Ltd.); Turbo sieve (manufactured by Turbo Corporation); Micron sieve (manufactured by Makino Mfg. Co., Ltd.); and Circular vibrating sieve.

[0195] Various measurement methods, etc.

[0196] Method for observing the toner cross-section under a transmission electron microscope (TEM)

[0197] Observation of the domain-matrix structure is performed after ruthenium staining of the toner particle cross-section.

[0198] First, the toner was spread on a cover glass (Matsunami Glass Ind., Ltd., square cover glass No. 1) to form a layer. Then, the toner was covered with an Os film (5 nm) and a naphthalene film (20 nm) used as a protective film by using an osmium plasma coater (Filgen, Inc., OPC80T). Next, a PTFE tube (Φ1.5 mm × Φ3 mm × 3 mm) was filled with a photocurable resin D800 (JEOL Ltd.), and the cover glass was gently placed on the tube so that the toner came into contact with the photocurable resin D800. In this state, the resin was cured by irradiating light, and then the cover glass and the tube were removed to form a cylindrical resin with the toner embedded in the outermost surface. Using an ultramicrotome (Leica, UC7), cutting was performed from the outermost surface of the cylindrical resin at a cutting speed of 0.6 mm / s for a length corresponding to the radius of the toner (4.0 μm in the case where the weight-average particle size (D4) was 8.0 μm), thereby exposing the cross-section of the toner. Next, cutting was performed to a thickness of 250 nm to prepare a thin slice sample of the toner cross-section. By cutting in this way, a cross-section of the central part of the toner could be obtained.

[0199] The obtained thin slice sample was stained in an atmosphere of RuO4 gas at 500 Pa for 15 minutes using a vacuum electron staining device (Filgen, Inc., VSC4R1H), and STEM observation was performed using a TEM (JEOL Ltd., JEM2800).

[0200] The probe size in STEM observation was 1 nm, and an image with a size of 1024 × 1024 pixels was acquired.

[0201] The obtained bright-field image was binarized using image processing software "Image-Pro Plus (manufactured by Media Cybernetics Inc.)". In binarization, the brightness change from black to white was represented by 0 to 255 gray levels, and the part below 127 gray levels was converted to black, and the part above 128 gray levels was converted to white.

[0202] In the cross-section observation of the toner particles, the part containing the crystalline resin was the part that showed black after binarization, and the part containing the non-crystalline resin was the part that showed white after binarization.

[0203] Using the binarized STEM image, it was judged whether a domain-matrix structure was observed in the cross-section of the toner particles. In addition, it was judged whether the domain and the matrix each contained a crystalline resin or a non-crystalline resin.

[0204] Principle of ruthenium staining

[0205] When ruthenium staining is performed on the cross-section of toner particles, the crystalline resin component is more strongly stained with ruthenium than the non-crystalline resin component to form a distinct contrast, thus facilitating the observation of the cross-section of toner particles. This is because RuO4 has strong oxidizing ability and oxidizes the long-chain alkyl and alkylene groups that enhance crystallinity. As a result, the crystalline resin component is more strongly stained than the non-crystalline resin component.

[0206] The higher the crystallinity of the resin component, the greater the amount of ruthenium atoms present, and the greater the amount of ruthenium atoms present, the less the electron beam passes through; therefore, in the electron microscope image, the resin component with higher crystallinity is observed to be more strongly stained. In contrast, the non-crystalline resin component is observed to be weakly stained or not stained. Thus, it can be judged that the strongly stained part is the part containing the crystalline resin, and the weakly stained or non-stained part is the part containing the non-crystalline resin.

[0207] Method for analyzing matrix and domains in cross-section observation of toner

[0208] First, a thin slice serving as a standard sample for the amount present is prepared.

[0209] The crystalline resin A is sufficiently dispersed in a visible light-curable resin (Aronix LCR series D800), and then cured by irradiation with short-wavelength light. The obtained cured product is cut with an ultramicrotome equipped with a diamond knife to prepare a 250-nm thin slice sample. Similarly, a thin slice sample of the non-crystalline resin B is prepared.

[0210] In addition, the crystalline resin A and the non-crystalline resin B are mixed at mass ratios of 0 / 100, 30 / 70, 70 / 30, and 100 / 0 and melt-kneaded to prepare kneaded products. These kneaded products are also each dispersed in a visible light-curable resin, cured, and then cut to prepare thin slice samples.

[0211] Subsequently, the cross-section of the cut samples (i.e., standard samples) is observed using a transmission electron microscope (electron microscope JEM-2800 manufactured by JEOL Ltd.) (TEM-EDX), and elemental mapping is performed using EDX. The elements to be mapped are carbon, oxygen, and nitrogen.

[0212] The mapping conditions are as follows: acceleration voltage, 200 kV; electron beam irradiation size, 1.5 nm; live time limit, 600 sec; dead time, 20 to 30 seconds; mapping resolution, 256×256.

[0213] Based on the (average of the spectral intensities in an area of 10 nm square) of each element, (oxygen element intensity / carbon element intensity) and (nitrogen element intensity / carbon element intensity) are calculated, and a calibration curve is constructed with respect to the mass ratio of crystalline resin A to amorphous resin B. When the monomer unit of crystalline resin A contains a nitrogen atom, the calibration curve of (nitrogen element intensity / carbon element intensity) is used for subsequent quantification.

[0214] Next, the toner sample is analyzed. The toner is sufficiently dispersed in a visible light curable resin (Aronix LCR series D800), and then cured by irradiating with short wavelength light. The obtained cured product is cut using an ultramicrotome equipped with a diamond knife to prepare a 250 nm thin sheet sample. Subsequently, the cut sample is observed using a transmission electron microscope (electron microscope JEM-2800 manufactured by JEOL Ltd.) (TEM-EDX). A cross-sectional image of the toner particles is obtained, and elemental mapping is performed using EDX. The elements to be mapped are carbon, oxygen, and nitrogen.

[0215] The cross-section of the toner to be observed is selected as follows. First, the cross-sectional area of the toner is obtained from the toner cross-sectional image, and the diameter of a circle (circular equivalent diameter) having an area equal to the cross-sectional area is obtained. Only the cross-sectional image of the toner having a weight average particle diameter (D4) with an absolute difference in circular equivalent diameter of 1.0 μm or less is observed.

[0216] For the domains and matrix observed in the observation image, (oxygen element intensity / carbon element intensity) and / or (nitrogen element intensity / carbon element intensity) are calculated based on the (average in a 10 nm square) spectral intensity of each element. The ratio of crystalline resin A to amorphous resin B can be calculated by comparing the calculation results with the above calibration curve.

[0217] Method for measuring the maximum endothermic peak temperature

[0218] The measurement of the endothermic peak temperature is performed using DSC Q1000 (manufactured by TA Instruments) under the following conditions: heating rate, 10 °C / min; measurement start temperature, 20 °C; measurement end temperature, 180 °C. For the temperature correction of the detection unit of the device, the melting points of indium and zinc are used. For the correction of heat, the heat of fusion of indium is used.

[0219] Specifically, approximately 5 mg of the sample is accurately weighed and placed in an aluminum pan, and differential scanning calorimetry is performed. A silver empty pan is used as a reference.

[0220] In the measurement, the temperature is first raised to 180 °C (the first heating process), then the temperature is lowered to 20 °C, and thereafter, the temperature is raised again (the second heating process). In the DSC curve obtained during the second heating process, the peak temperature (Tm) of the maximum endothermic peak in the temperature range from 20 °C to 180 °C is determined.

[0221] The maximum endothermic peak refers to the peak having the maximum endothermic value in the range from 20 °C to 180 °C.

[0222] The reason for not performing the above measurement during the first heating process is that resins and the like produced through a production process including a heat treatment step may show behavior due to this heat treatment (for example, an endothermic peak due to relaxation of the resin) during the first heating process in DSC. This behavior may coincide with the inherent behavior of the sample, making accurate measurement difficult.

[0223] However, it is known that the first heating process equalizes such behavior, and during the second heating process performed after lowering the temperature of the sample, the behavior due to this heat treatment disappears or becomes less obvious. Therefore, in the present disclosure, the above measurement is performed during the second heating process to measure the inherent behavior of the sample.

[0224] Method for measuring storage elastic modulus (G')

[0225] As the measuring device, a rotary plate rheometer "ARES" (manufactured by TA Instruments) is used. As the sample, a sample obtained by pressing a toner into a disc shape with a diameter of 8.0 mm and a thickness of 2.0 ± 0.3 mm using a tablet press in an environment of 25 °C is used.

[0226] Place the sample between the parallel plates and increase the temperature from room temperature (25 °C) to 55 °C over 15 minutes to adjust the shape of the sample. Then lower the temperature to the temperature at the start of the viscoelasticity measurement and start the measurement. At this time, set the sample so that the initial normal force is 0. As described below, in subsequent measurements, the influence of the normal force can be eliminated by turning on the automatic tension adjustment. Conduct the measurement under the following conditions. (1) Use parallel plates with a diameter of 7.9 mm. (2) Set the frequency to 6.28 rad / sec (1.0 Hz). (3) Set the initial value of the applied strain to 0.1%. (4) Conduct the measurement at a heating rate of 2.0 °C / min from 30 °C to 200 °C. Conduct the measurement under the following set conditions of the automatic adjustment mode. Conduct the measurement in the automatic strain adjustment mode. (5) Set the maximum applied strain to 20.0%. (6) Set the maximum allowable torque to 200.0 g·cm and the minimum allowable torque to 0.2 g·cm. (7) Set the strain adjustment to 20.0% of the current strain. During the measurement, use the automatic tension adjustment mode. (8) Set the automatic tension direction to compression. (9) Set the initial static force to 10.0 g and the automatic tension sensitivity to 40.0 g. (10) The automatic tension operates at a sample modulus of 1.0×10 3 Pa or more.

[0227] Method for measuring tanδ

[0228] The measurement of tanδ is carried out using a viscoelasticity measurement device (rheometer) ARES (manufactured by Rheometric Scientific). Measurement jig: Torsion rectangle. Measurement sample; from toner, use a compression molding machine to produce a rectangular parallelepiped sample with a width of approximately 12 mm, a height of approximately 20 mm, and a thickness of approximately 2.5 mm (held at 15 kN for one minute at room temperature). The compression molding machine used is a 100 kN press NT-100H manufactured by NPa System Co., Ltd.

[0229] After leaving the jig and the sample standing at room temperature (23 °C) for one hour, mount the sample onto the jig. Fix the sample so that the part with a measurement width of approximately 12 mm, a thickness of approximately 2.5 mm, and a height of 10.0 mm is measured. After adjusting the temperature to the measurement start temperature of 30 °C over 10 minutes, conduct the measurement under the following set conditions: measurement frequency, 6.28 rad / s; setting of the measurement strain, set the initial value to 0.1% and conduct the measurement in the automatic measurement mode; correction of the sample elongation rate, adjust in the automatic measurement mode; measurement temperature, increase the temperature from 30 °C to 180 °C at a rate of 2 °C / min; and measurement interval, measure the viscoelasticity data at 30-second intervals, i.e., at 1 °C intervals.

[0230] Transfer the data through the interface to RSI Orchestrator (control, data collection, and analysis software) (manufactured by Rheometrics Scientific) that can run on Windows 7 manufactured by Microsoft Corporation. Determine the maximum value of tanδ in the data within the range of 30°C to 150°C as tanδ(Max).

[0231] Method for measuring the content of each monomer unit in a resin

[0232] The measurement of the content of monomer units in the resin is carried out by 1 1H-NMR under the following conditions: measuring device, FT-NMR device JNM-EX400 (manufactured by JEOL Ltd.); measuring frequency, 400 MHz; pulse condition, 5.0 μs; frequency range, 10500 Hz; number of scans, 64 times; measuring temperature, 30°C; and sample, place 50 mg of the measurement sample in a sample tube with an inner diameter of 5 mm, add deuterated chloroform (CDCl3) as a solvent, and dissolve the resulting mixture in a constant temperature bath at 40°C to prepare the sample.

[0233] When using vinyl-based polymer A as the measurement sample, among the peaks of monomer unit A in the obtained 1H-NMR spectrum, select the peaks independent of the peaks attributed to the components of other monomer units, and calculate the integral value S1 of these peaks. When polymerizable monomer B (hereinafter referred to as monomer unit B) is included as a constituent monomer, among the peaks attributed to its components, select the peaks independent of the peaks attributed to the components of other monomer units, and calculate the integral value S2 of these peaks. 1 When monomer unit C is included, among the peaks attributed to its components, select the peaks independent of the peaks attributed to the components of other monomer units, and calculate the integral value S3 of these peaks.

[0234] When polymerizable monomer D (hereinafter referred to as monomer unit D) is included as a constituent monomer, among the peaks attributed to its components, select the peaks independent of the peaks attributed to the components of other monomer units, and calculate the integral value S4 of these peaks.

[0235]

[0236] ​The integral values S1, S2, S3, and S4 are used as described below to determine the contents of monomer units A, B, C, and D. n1, n2, n3, and n4 each represent the number of hydrogen atoms in the constituent element to which the peak of interest for each unit belongs. M1, M2, M3, and M4 are the molecular weights of the monomer units. The content of monomer unit A (mol%) = { (S1 / n1 × M1) / ((S1 / n1 × M1) + (S2 / n2 × M2) + (S3 / n3 × M3) + (S4 / n4 × M4))} × 100. Similarly, the contents of monomer units B, C, and D are determined by the following formulas. The content of monomer unit B (mol%) = { (S2 / n2 × M2) / ((S1 / n1 × M1) + (S2 / n2 × M2) + (S3 / n3 × M3) + (S4 / n4 × M4))} × 100. The content of monomer unit C (mol%) = { (S3 / n3 × M3) / ((S1 / n1 × M1) + (S2 / n2 × M2) + (S3 / n3 × M3) + (S4 / n4 × M4))} × 100. The content of monomer unit D (mol%) = { (S4 / n4 × M4) / ((S1 / n1 × M1) + (S2 / n2 × M2) + (S3 / n3 × M3) + (S4 / n4 × M4))} × 100. When a polymerizable monomer that does not contain hydrogen atoms is used as a constituent element other than vinyl in Polymer A, the nucleus to be measured is 13 C's 13 C-NMR is measured in single-pulse mode and by means of 1 H-NMR is calculated in the same manner.

[0237] Method for calculating the SP value

[0238] The SP value is determined as described below according to the calculation method proposed by Fedors.

[0239] For the atoms or atomic groups in the molecular structure to be calculated, the evaporation energy (Δei) (cal / mol) and molar volume (Δvi) (cm 3 / mol) are obtained from the table described in "Polym. Eng. Sci., 14(2), 147 - 154(1974)". The SP value (J / cm 3 ) 0.5 is calculated by (4.184 × ΣΔei / ΣΔvi) 0.5 .

[0240] The SP is calculated from the constitution of the monomer units contained in the non-crystalline resin used for production P . The SP B is calculated based on individual monomers.

[0241] Method for measuring the content of THF-insoluble substances in the resin component

[0242] As a measurement sample, accurately weigh 1.5 g of toner (in the case of using only the resin component as the measurement sample, 0.7 g of the resin component) (W1 [g]) and place it in a pre-precisely weighed extraction thimble (trade name: No. 86R, size 28×100 mm, manufactured by Advantec Toyo Kaisha, Ltd.). Place the extraction thimble with the toner in a Soxhlet extractor.

[0243] Use 200 mL of tetrahydrofuran (THF) as a solvent for extraction for 18 hours. This extraction is carried out at a reflux rate at which one cycle of solvent extraction ends in about 5 minutes.

[0244] After completion of the extraction, take out the extraction thimble and air-dry it, then vacuum-dry it at 40 °C for 8 hours. Weigh the mass of the extraction thimble including the extraction residue, and subtract the mass of the extraction thimble to calculate the mass of the extraction residue (W2 [g]).

[0245] When recovering THF-soluble substances, they can be recovered by distilling off THF from the soluble substances in THF sufficiently using an evaporator.

[0246] Next, the content (W3 [g]) of components other than the resin component is determined according to the following procedure (in the following procedure, if only the resin component is used as the measurement sample, then W3 is 0 g).

[0247] Accurately weigh about 2 g of toner (W a [g]) in a pre-weighed 30 mL magnetic crucible.

[0248] Place the magnetic crucible in an electric furnace, heat it at about 900 °C for about 3 hours, and let it cool in the electric furnace. At room temperature, let the magnetic crucible cool in a desiccator for more than 1 hour. Weigh the mass of the crucible containing the incineration ash, and subtract the mass of the crucible to calculate the mass of the incineration ash (W b [g]).

[0249] The mass (W3 [g]) of the incineration ash in the W1 [g] sample is calculated by Equation (6): W3 = W1 × (W b / W a ) ··· (6). The content of THF-insoluble substances in the resin component can be calculated by Equation (7) using W1, W2, and W3: Content of THF-insoluble substances in the resin component (mass%) = {(W2 - W3) / (W1 - W3)} × 100 ··· (7).

[0250] Examples

[0251] The present disclosure will be described more specifically with reference to the embodiments, but these embodiments are not intended to limit the present disclosure.

[0252] Production Example of Crystalline Resin A-1

[0253] In a nitrogen atmosphere, the following materials were charged into a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube.

[0254] Toluene, 100.0 parts; behenyl acrylate (polymerizable monomer A), 64.0 parts; methacrylic acid (polymerizable monomer B), 3.0 parts; styrene (polymerizable monomer C), 17.0 parts; acrylonitrile (polymerizable monomer D), 16.0 parts; and tert-butyl perpivalate (Perbutyl PV manufactured by NOF Corporation), 3.0 parts. The materials (monomer composition) in the reaction vessel were heated to 70 °C with stirring at 200 rpm for 12 hours to carry out a polymerization reaction, thereby obtaining a solution of the polymer of the monomer composition in toluene. Subsequently, the solution was cooled to 25 °C and then poured into 1000.0 parts of methanol with stirring to precipitate methanol-insoluble substances. The methanol-insoluble substances were separated by filtration, washed with methanol, and then dried in vacuo at 40 °C for 24 hours to obtain crystalline resin A-1, whose SP B was 22.0. Polymer A-1 is a crystalline resin that shows a distinct endothermic peak in DSC. The physical properties of polymer A-1 are shown in Table 1.

[0255] Production Examples of Amorphous Resins B-1 to B-9

[0256] Except that the polymerizable monomers A, B, C, and D used were changed as shown in Table 1, crystalline resins A-2 to A-9 were obtained in the same manner as crystalline resin A-1. Polymers A-2 to A-9 are each crystalline resins that show a distinct endothermic peak in DSC. The physical properties of polymers A-2 to A-9 are shown in Table 1.

[0257] Table 1

[0258]

[0259] The abbreviations in Table 1 are as follows: BEA, behenyl acrylate; STA, stearyl acrylate; MYA, myristyl acrylate; OCA, octacosa acrylate; MA, methacrylic acid; VSA, vinylsulfonic acid; St, styrene; and AN, acrylonitrile.

[0260] Production Example of Amorphous Resin B-1

[0261] In a nitrogen atmosphere, the following materials were charged into a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube. An ethylene oxide (2 mol) adduct of bisphenol A, 73.0 parts; terephthalic acid, 23.0 parts; and titanium diisopropoxy bistriethanolaminate, 2.5 parts. Under a nitrogen stream, these materials were reacted at 230°C for 2 hours while distilling off the water formed. Next, the reaction was carried out under a reduced pressure of 2.5 kPa for 5 hours, and then the temperature was lowered to 180°C. 1 part of tert-butylcatechol used as a polymerization inhibitor was added to the reaction product, and further 60.0 parts of fumaric acid were added. The reaction was carried out under a reduced pressure of 0.5 to 2.5 kPa for 8 hours, and then the reaction product was taken out to obtain an amorphous resin B-1. The SP value of the amorphous resin B-1 was calculated by the above method. SP P was 23.3.

[0262] Production Example of Binder Resin C-1

[0263] Crystalline resin A-1 (60 parts by amount) and amorphous resin B-1 (40 parts by amount) were mixed and supplied to a twin-screw kneader (S5KRC kneader manufactured by Kurimoto, Ltd.) at 20 kg / h. At the same time, 4.0 parts of tert-butyl peroxyisopropyl monocarbonate used as a radical reaction initiator was supplied at 0.8 kg / h. Kneading and extrusion were carried out at 160°C at 80 rpm for 10 minutes to cause a reaction. Further, a nitrogen stream was passed through the vent, and mixing was carried out while removing the organic solvent. The obtained mixture was cooled to obtain binder resin C-1.

[0264] Production Examples of Binder Resins C-2 to C-18

[0265] Binder resins C-2 to C-18 were obtained in the same manner as binder resin C-1 except that the crystalline resin A, amorphous resin B, and tert-butyl peroxyisopropyl monocarbonate used were changed as shown in Table 2.

[0266] Table 2

[0267]

[0268] Production Example of Toner 1

[0269] The binder resin C-1 (in an amount of 100.0 parts by mass), carbon black (Nipex 35 manufactured by Orion Engineered Carbons) (in an amount of 5.0 parts by mass), and a mold release agent (EXCEREX 15341PA manufactured by Mitsui Chemicals, Inc.) (in an amount of 5.0 parts by mass) were premixed in a Henschel mixer, and then melt-kneaded using a twin-screw extruder (trade name: PCM-30, manufactured by Ikegai Corporation) with the temperature set such that the temperature of the melt at the discharge port was 150 °C.

[0270] The obtained kneaded product was cooled, coarsely pulverized with a hammer mill, and then finely pulverized using a pulverizer (trade name: Turbo Mill T250, manufactured by Freund-Turbo Corporation). The obtained finely pulverized powder was classified using a multi-stage classifier utilizing the wall effect to obtain toner particles 1 having a weight-average particle diameter (D4) of 7.2 μm.

[0271] To 100.0 parts by mass of the toner particles 1, 1.0 part by mass of hydrophobic silica fine powder surface-treated with hexamethyldisilazane (number-average particle diameter of primary particles: 10 nm) was added, and the mixture was mixed using a Henschel mixer at 3200 rpm for 2 minutes to obtain toner 1. The physical properties of toner 1 are shown in Table 3.

[0272] Table 3

[0273]

[0274] The physical properties of the toner shown in Table 3 were measured by the above measurement methods.

[0275] Production examples of toner 2 to 18

[0276] Toner 2 to 18 were obtained in the same manner as toner 1, except that the type of the binder resin used was changed as shown in Table 3. The physical properties of toner 2 to 18 are shown in Table 3.

[0277] Example 1

[0278] Toner 1 was evaluated in the following manner. The evaluation results are shown in Table 4.

[0279] Evaluation of low-temperature fixability of the toner

[0280] The evaluation of low-temperature fixability was carried out using a modified machine of a color laser printer (HP Color LaserJet 3525dn manufactured by HP Inc.) as the image forming apparatus and white paper (Office Planner manufactured by CANON KABUSHIKI KAISHA; 64 g / m 2 ) as the evaluation paper. The image forming apparatus was modified so that the fixing temperature and the processing speed could be varied and the fixing unit could be detached.

[0281] First, the fixing unit was detached from the image forming apparatus, and the toner was taken out from the black cartridge. Toner 1 (amount: 100 g) was loaded into the cartridge.

[0282] Subsequently, using the loaded Toner 1, an unfixed toner image having a length of 2.0 cm and a width of 15.0 cm was formed in a portion 1.0 cm from the top along the paper passing direction on the evaluation paper (toner loading amount: 0.9 mg / cm 2 ) to obtain an unfixed image.

[0283] For fixing the unfixed image, an external fixing device modified to operate outside the laser beam printer was used. In a normal temperature and normal humidity environment (23°C and 60% RH), the processing speed of the external fixing device was set to 410 mm / s, and at the same time, the set temperature was sequentially increased in 5°C increments starting from the initial fixing temperature of 100°C, and the unfixed image was fixed at each temperature to obtain a fixed image. For the fixed image, the fixing temperature at which low-temperature smudging does not occur was determined as the lowest fixing temperature, and the value of the lowest fixing temperature was used to evaluate the low-temperature fixability. A toner having a lowest fixing temperature of 130°C or lower was judged to have the advantageous effects of the present disclosure.

[0284] Evaluation of fixing device contamination

[0285] After the evaluation of the low-temperature fixability of the toner, the fixing device contamination was evaluated using the image forming apparatus and the evaluation paper used for the evaluation of the low-temperature fixability. In the evaluation of the fixing device contamination, the degree of contamination of the fixing device and the degree of image contamination accompanying the contamination of the fixing device were evaluated while increasing the toner loading amount on the evaluation paper while maintaining the above-mentioned lowest fixing temperature. Therefore, the fixing temperature at the time of image output was set to the above-mentioned lowest fixing temperature, and the following image output was performed.

[0286] Under normal temperature and humidity environment (23 °C and 60% RH), the processing speed is set to 410 mm / s, and 300 white image evaluation papers with a printing rate of 0% are continuously output. Without pausing, one black image evaluation paper is output, on which an image with a front margin of 5 mm, a width of 100 mm, and a length of 100 mm is formed (toner loading: 1.5 mg / cm 2 ). Thereafter, the contamination of the fixing device is inspected, and five white image evaluation papers with a printing rate of 0% are output. Based on the five white image evaluation papers output after outputting one black image evaluation paper and the contamination of the fixing device, the contamination of the fixing device is evaluated according to the following criteria. In the following criteria, A to C are judged to have the advantageous effects of the present disclosure.

[0287] A: No contamination is observed in the fixing device, and no image defects are observed in the white image evaluation paper. B: Contamination is observed in the fixing device, but no image defects are observed in the white image evaluation paper. C: Contamination is observed in the fixing device, and image contamination due to the contamination of the fixing device is observed in the first white image evaluation paper, but disappears by the fifth white image evaluation paper. D: Contamination is observed in the fixing device, and image contamination due to the contamination of the fixing device is observed in the first white image evaluation paper, but becomes slight by the fifth white image evaluation paper. E: Contamination is observed in the fixing device, and image contamination due to the contamination of the fixing device remains and does not become slight from the first white image evaluation paper to the fifth white image evaluation paper.

[0288] Evaluation of heat-resistant storage stability

[0289] Toner 1 (in an amount of 5 g) is placed in a 50 cc plastic cup and left standing at a temperature of 50 °C and a humidity of 80% RH for 24 hours. The presence or absence of aggregates of toner 1 after standing is inspected, and the heat-resistant storage stability is evaluated according to the following criteria. In the following criteria, A to C are judged to have the advantageous effects of the present disclosure.

[0290] A: No aggregates are formed. B: Small aggregates are formed, but break when gently pressed with a finger. C: Aggregates are formed, but break when gently pressed with a finger. D: Completely aggregated and do not break when pressed hard with a finger.

[0291] Examples 2 to 12

[0292] Toner 2 to 12 are evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0293] Comparative Examples 1 to 6

[0294] Toner 13 to 18 were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0295] Table 4

[0296] Toner Low-temperature fixability Fixing device contamination Heat-resistant storage stability Example 1 Toner 1 115℃ A A Example 2 Toner 2 110℃ A A Example 3 Toner 3 130℃ A A Example 4 Toner 4 120℃ A A Example 5 Toner 5 105℃ B A Example 6 Toner 6 100℃ C A Example 7 Toner 7 135℃ A A Example 8 Toner 8 115℃ C A Example 9 Toner 9 110℃ A C Example 10 Toner 10 120℃ A A Example 11 Toner 11 130℃ A A Example 12 Toner 12 115℃ A A Comparative Example 1 Toner 13 140℃ B A Comparative Example 2 Toner 14 130℃ D A Comparative Example 3 Toner 15 125℃ E A Comparative Example 4 Toner 16 100℃ E A Comparative Example 5 Toner 17 155℃ A A Comparative Example 6 Toner 18 145℃ D A

[0297] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A toner comprising toner particles, the toner particles containing a resin component including a crystalline resin and an amorphous resin, It is characterized in that, In a cross-sectional observation of the toner particles, a domain-matrix structure including a matrix containing the crystalline resin and domains containing the amorphous resin is observed, The maximum endothermic peak temperature Tm of the toner measured by a differential scanning calorimeter DSC is 50 °C to 80 °C in °C, G'(-5) and G'(+5) satisfy the inequality (1): G'(-5) / G'(+5) ≥ 50 ··· (1) where G'(-5) is the storage elastic modulus of the toner at a temperature 5 °C lower than Tm, in Pa; G'(+5) is the storage elastic modulus of the toner at a temperature 5 °C higher than Tm, in Pa, and tanδ(Max) satisfies the inequality (2): 0.0 < tanδ(Max) ≤ 1.50 ··· (2) where tanδ(Max) is the maximum loss tangent of the toner in the temperature range of 50 °C to 130 °C, The crystalline resin is a vinyl-based polymer A containing monomer unit A represented by formula (A): Among them, in formula (A), R 1 represents H or CH3, and R 2 represents an alkyl group having 18 to 36 carbon atoms, The vinyl-based polymer A further contains monomer unit B, and the monomer unit B has at least one selected from the group consisting of a carboxyl group and a sulfo group, The vinyl-based polymer A further contains monomer unit D, and the monomer unit D is at least one monomer unit selected from the group consisting of monomer unit represented by formula (D) and monomer unit represented by formula (E): wherein, in formula (D) and formula (E), X represents a single bond or an alkylene group having 1 to 6 carbon atoms, and R 4 represents -C≡N, -C(=O)NHR 7 , hydroxyl, -COOR 8 , -NHCOOR 9 , -NH-C(=O)-NH(R 10 )2, -COO(CH2)2NHCOOR 11 or -COO(CH2)2-NH-C(=O)-NH(R 12 )2, wherein R 7 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R 8 is an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms, R 9 is an alkyl group having 1 to 4 carbon atoms, each R 10 is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 11 is an alkyl group having 1 to 4 carbon atoms, each R 12 is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 6 represents an alkyl group having 1 to 4 carbon atoms, and R 3 and R 5 each independently represents a hydrogen atom or CH3, and The resin component contains a tetrahydrofuran-insoluble substance, and the content of the tetrahydrofuran-insoluble substance is 5.0 mass% to 80.0 mass% relative to the content of the resin component, The tetrahydrofuran-insoluble substance contains a crosslinked resin in which the crystalline resin and the amorphous resin are bonded to each other.

2. The toner according to claim 1, wherein tanδ(Max) satisfies the inequality (3): 0.0 < tanδ(Max) ≤ 0.98 ··· (3).

3. The toner according to claim 1 or 2, wherein G'(+5) is from 1.00×10 4 Pa to 1.00×10 6 Pa.

4. The toner according to claim 1 or 2, wherein the content of the monomer unit A is 30.0 mass% to 99.9 mass% relative to the content of the vinyl-based polymer A.

5. The toner according to claim 1 or 2, wherein the content of the monomer unit B is 0.5 mass% to 30.0 mass% relative to the content of the vinyl-based polymer A.

6. The toner according to claim 1 or 2, wherein the vinyl-based polymer A further contains monomer unit C, and the monomer unit C is at least one monomer unit selected from the group consisting of monomer unit represented by formula (B) and monomer unit represented by formula (C): Among them, In formula (C), R 13 represents H or CH3.

7. The toner according to claim 1 or 2, wherein the mixing ratio of the crystalline resin to the amorphous resin is 40 / 60 to 95 / 5 by mass fraction.

8. A method for producing a toner according to claim 1, characterized in that, The method includes: A step of obtaining a kneaded product by melt-kneading a mixture containing a vinyl-based polymer A having crystallinity, an amorphous resin, and a radical initiator; and A step of obtaining a pulverized product by pulverizing the kneaded product, The vinyl-based polymer A contains a monomer unit A represented by formula (A), a monomer unit B having at least one selected from the group consisting of a carboxyl group and a sulfo group, and a monomer unit D which is at least one monomer unit selected from the group consisting of a monomer unit represented by formula (D) and a monomer unit represented by formula (E): Among them, in formula (A), R 1 represents H or CH3, and R 2 represents an alkyl group having 18 to 36 carbon atoms, Among them, in formula (D) and formula (E), X represents a single bond or an alkylene group having 1 to 6 carbon atoms, R 4 represents -C≡N, -C(=O)NHR 7 , a hydroxyl group, -COOR 8 , -NHCOOR 9 , -NH-C(=O)-NH(R 10 )2, -COO(CH2)2NHCOOR 11 or -COO(CH2)2-NH-C(=O)-NH(R 12 )2, where R 7 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R 8 is an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms, R 9 is an alkyl group having 1 to 4 carbon atoms, each R 10 is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 11 is an alkyl group having 1 to 4 carbon atoms, each R 12 is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 6 represents an alkyl group having 1 to 4 carbon atoms, and R 3 and R 5 each independently represents a hydrogen atom or CH3, The amorphous resin has a carbon-carbon double bond, The mixing ratio of the vinyl-based polymer A to the amorphous resin is 40 / 60 to 95 / 5 by mass fraction, and SP P and SP B satisfy the inequality (4): |SP P -SP B |≤5.0···(4) wherein SP P (J / cm 3 ) 0.5 is the solubility parameter SP value of the non-crystalline resin, and SP B (J / cm 3 ) 0.5 is the SP value of the monomer unit B.

9. The method for producing a toner according to claim 8, wherein the amorphous resin is a polyester.

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