Toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming device, and image forming method

Abstract

To provide a toner for electrostatic charge image development which can form an image in which gloss level differences are suppressed, while having low temperature fixability.SOLUTION: A toner for electrostatic charge image development has a toner particle including an amorphous resin and a crystalline resin as binder resins, and an external additive. The external additive contains an inorganic particle of a specific gravity of 1.3 or more and 2.0 or less. In a dynamic viscoelasticity measurement of the toner particle, where the temperature is lowered from 110°C to 30°C, a ratio tanδ(80) / tanδ(60) of a loss tangent tanδ(80) at a temperature of 80°C to a loss tangent tanδ(60) at a temperature of 60°C is 0.90 or more and 1.40 or less, and the loss tangent tanδ(80) at a temperature of 80°C is 1.20 or more and 1.70 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a toner for developing an electrostatic image, an electrostatic image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method. [Background technology]

[0002] Patent Document 1 states, "An electrostatic image developing toner containing toner particles containing a binder resin, wherein in a dynamic viscoelasticity measurement of the electrostatic image developing toner, when the loss tangent tanδ at a temperature of 90°C and a strain of 1% is D1(90), the loss tangent tanδ at a temperature of 90°C and a strain of 50% is D50(90), the loss tangent tanδ at a temperature of 150°C and a strain of 1% is D1(150), and the loss tangent tanδ at a temperature of 150°C and a strain of 50% is D50(150) , D1(90), D50(90), D1(150), and D50(150) are each 0.5 or more and 2.5 or less, the value of D50(150) - D1(150) is less than 1.5, and the value of D50(90) - D1(90) is less than 1.0, the toner particles further contain resin particles, and the number average molecular weight of the tetrahydrofuran soluble matter in the toner particles is 5,000 or more and 15,000 or less."

[0003] Patent Document 2 states that "the crystalline material contains wax and crystalline polyester, In a dynamic viscoelasticity measurement performed by cooling the toner from 100°C, when the storage moduli at 100°C and 60°C are G'(100°C) and G'(60°C), respectively, the toner satisfies the following formulas (1) and (2): "A toner characterized in that the integrated value of stress measured using a tack tester when a probe is brought into contact with a pellet of the toner and the temperature is lowered from 100°C to 25°C is 0.4 N·s or less." Formula (1) G'(100℃)≦3.6×10 6 (Pa) Formula (2) G'(60℃) / G'(100℃)≦7.0×10 2 [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-48127 [Patent Document 2] JP 2018-173500 A Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to provide an electrostatic image developing toner that has toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, and that can form images with reduced gloss unevenness while maintaining low-temperature fixability compared to when the inorganic particles used as the external additive have a specific gravity of less than 1.3 or more than 2.0, or when the toner particles have a ratio tanδ(80) / tanδ(60) of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), in dynamic viscoelasticity measurement when the temperature is lowered from 110°C to 30°C, of ​​less than 0.90 or more than 1.40, or when the loss tangent tanδ(80) at a temperature of 80°C is less than 1.20 or more than 1.70. [Means for solving the problem]

[0006] Means for solving the above problems include the following aspects. <1> The toner includes toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, the external additive contains inorganic particles having a specific gravity of 1.3 or more and 2.0 or less, The toner for developing electrostatic images has, in a dynamic viscoelasticity measurement of the toner particles when cooled from 110°C to 30°C, a ratio of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), of 0.90 or more and 1.40 or less, and the loss tangent tanδ(80) at a temperature of 80°C is 1.20 or more and 1.70 or less. <2> The volume average particle size of the inorganic particles is 30 nm or more and 80 nm or less. <1> 2. The toner for developing electrostatic images according to claim 1. <3> The toner particles contain internally added crosslinked resin particles. <1> or <2> 2. The toner for developing electrostatic images according to claim 1. <4> The glass transition temperature Tg of the internally crosslinked resin particles is 0°C or higher and 40°C or lower. <3> 2. The toner for developing electrostatic images according to claim 1. <5> The ratio of the content of the crystalline resin to the external amount of the inorganic particles (external amount of inorganic particles / content of crystalline resin) is 1.0×10 -2 Over 10.0 x 10 -2 is <1> ~ <4> 10. The toner for developing electrostatic images according to claim 9. <6> The ratio of the content of the crystalline resin to the external amount of the inorganic particles (external amount of inorganic particles / content of crystalline resin) is 2.0×10 -2 Over 8.0 x 10 -2 is <5> 2. The toner for developing electrostatic images according to claim 1. <7> The crystalline resin is a crystalline polyester resin. <1> ~ <6> 10. The toner for developing electrostatic images according to claim 9. <8> The content of the crystalline resin relative to the binder resin is 10% by mass or more and 30% by mass or less. <1> ~ <7> 10. The toner for developing electrostatic images according to claim 9. <9> the toner particles contain one or more metal ions selected from the group consisting of Al, Mg, and Ca; The ratio AV1 / M1 of the amount M1 of the metal ions to the acid value AV1 of the binder resin is 1.0×10 3 Over 4.0 x 10 3 is <1> ~ <8> 10. The toner for developing electrostatic images according to claim 9. <10> The ratio AV1 / M1 of the amount M1 of the metal ions to the acid value AV1 of the binder resin is 2.0×10 3 Over 3.5 x 10 3is <9> 2. The toner for developing electrostatic images according to claim 1. <11> <1> ~ <10> 10. An electrostatic image developer comprising the toner for developing electrostatic images according to any one of claims 1 to 9. <12> <1> ~ <10> The toner for developing electrostatic images according to any one of the above items is contained, A toner cartridge that is detachably attached to an image forming device. <13> <11> a developing device that contains the electrostatic image developer according to claim 1 and develops an electrostatic image formed on the surface of an image carrier into a toner image by using the electrostatic image developer, A process cartridge is detachably mounted in an image forming apparatus. <14> an image carrier; a charging device that charges the surface of the image carrier; an electrostatic image forming device for forming an electrostatic image on the charged surface of the image carrier; <11> a developing device that contains the electrostatic image developer according to claim 1 and develops the electrostatic image formed on the surface of the image carrier into a toner image by using the electrostatic image developer; a transfer device that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing device for fixing the toner image transferred onto the surface of the recording medium; An image forming apparatus comprising: <15> a charging step of charging the surface of the image carrier; an electrostatic image forming step of forming an electrostatic image on the charged surface of the image carrier; <11> a developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image using the electrostatic image developer according to claim 1; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing step of fixing the toner image transferred onto the surface of the recording medium; An image forming method comprising the steps of: [Effects of the Invention]

[0007] <1> According to the invention related to (1), there is provided an electrostatic image developing toner having toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, wherein the electrostatic image developing toner has low-temperature fixing ability and can form images with reduced gloss unevenness, compared to when the inorganic particles used as the external additive have a specific gravity of less than 1.3 or more than 2.0, or when the toner particles have a ratio tanδ(80) / tanδ(60) of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), which is less than 0.9 or more than 1.40, or when the loss tangent tanδ(80) at a temperature of 80°C is less than 1.20 or more than 1.70, in dynamic viscoelasticity measurement when the temperature is lowered from 110°C to 30°C. <2> According to the invention, there is provided a toner for developing electrostatic images that has low-temperature fixing properties and can form images with reduced gloss unevenness, compared to when the volume average particle size of the inorganic particles is less than 30 nm or more than 80 nm.

[0008] <3> According to the invention, there is provided a toner for developing electrostatic images that can form images with reduced gloss unevenness while maintaining low-temperature fixability compared to toner particles that do not contain internally added crosslinked resin particles. <4> According to the invention, there is provided a toner for developing electrostatic images that can form images with reduced gloss unevenness while maintaining low-temperature fixability, as compared to when the glass transition temperature Tg of the internally added crosslinked resin particles is less than 0°C or more than 40°C. <5> According to the invention, the ratio of the content of the crystalline resin to the amount of externally added inorganic particles (amount of externally added inorganic particles / content of the crystalline resin) is 1.0×10 -2 Less than or 10.0 x 10 -2 The present invention provides a toner for developing electrostatic images that has low-temperature fixability and can form images with reduced gloss unevenness, as compared with a case where the toner exceeds 1000 kJ / cm 2 . <6> According to the invention, the ratio of the content of the crystalline resin to the amount of externally added inorganic particles (amount of externally added inorganic particles / content of the crystalline resin) is 2.0×10 -2 Less than or 8.0 x 10 -2The present invention provides a toner for developing electrostatic images that has low-temperature fixability and can form images with reduced gloss unevenness, as compared with a case where the toner exceeds 1000 kJ / cm 2 .

[0009] <7> According to the invention, there is provided a toner for developing electrostatic images, which comprises toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, and the external additive is an inorganic particle having a specific gravity of less than 1.3 or more than 2.0 as an external additive, or the toner particles have a specific gravity of less than 1.3 or more than 2.0 as ... The present invention provides a toner for developing electrostatic images that has low-temperature fixing ability and can form images with reduced gloss unevenness, even when the toner contains a crystalline polyester resin as the crystalline resin, compared to when the ratio of the loss tangent tanδ(80) to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), is less than 0.90 or exceeds 1.40, or when the loss tangent tanδ(80) at a temperature of 80°C is less than 1.20 or exceeds 1.70. <8> According to the invention, there is provided a toner for developing electrostatic images that has low-temperature fixing properties and can form images with reduced gloss unevenness, compared to when the content of the crystalline resin is less than 10% by mass or more than 30% by mass.

[0010] <9> According to the invention, the ratio AV1 / M1 of the amount of metal ions M1 to the acid value AV1 of the binder resin is 1.0×10 3 Less than or 4.0 x 10 3 The present invention provides a toner for developing electrostatic images that has low-temperature fixability and can form images with reduced gloss unevenness, as compared with a case where the toner exceeds 1000 kJ / cm 2 . <10> According to the invention, the ratio AV1 / M1 of the amount of metal ions M1 to the acid value AV1 of the binder resin is 2.0×10 3 Less than or 3.5 x 10 3 As compared with the above, a toner for developing electrostatic images is provided which has low-temperature fixability and can form images with reduced gloss unevenness.

[0011] <11> , <12> , <13> , <14> or <15> According to the invention related to (1), there is provided an electrostatic image developer, a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method, which is an electrostatic image developing toner having toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, and which is capable of forming images with reduced gloss unevenness while maintaining low-temperature fixability, compared to when an electrostatic image developing toner is used in which the inorganic particles as the external additive have a specific gravity of less than 1.3 or more than 2.0, or in which, in a dynamic viscoelasticity measurement of the toner particles when cooled from 110°C to 30°C, the ratio tanδ(80) / tanδ(60) of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C is less than 0.90 or more than 1.40, or the loss tangent tanδ(80) at a temperature of 80°C is less than 1.20 or more than 1.70. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram illustrating an example of a process cartridge that is detachably mounted to an image forming apparatus according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described. These descriptions and examples are intended to illustrate the embodiment and are not intended to limit the scope of the invention. In the present specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. In addition, in the present specification, the upper or lower limit of a numerical range may be replaced with a value shown in the examples. In this specification, (meth)acrylic means both acrylic and methacrylic.

[0014] In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved. Each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, the amount refers to the total amount of those multiple substances present in the composition, unless otherwise specified.

[0015] [Electrostatic image developing toner] The toner for developing electrostatic images (hereinafter also referred to as "toner") according to this embodiment contains toner particles containing an amorphous resin and a crystalline resin as binder resins, and an external additive. The external additive contains inorganic particles having a specific gravity of 1.3 or more and 2.0 or less. In dynamic viscoelasticity measurement of the toner particles when the temperature is lowered from 110°C to 30°C, the ratio tanδ(80) / tanδ(60) of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C is 0.90 or more and 1.40 or less, and the loss tangent tanδ(80) at a temperature of 80°C is 1.20 or more and 1.70 or less.

[0016] The toner according to this embodiment, due to the above-described configuration, can form an image with reduced gloss unevenness while having low-temperature fixability. The reason for this is presumed to be as follows.

[0017] From the viewpoints of energy saving, high-speed image formation, etc., low-temperature fixability of toner is required. By using a crystalline resin, it is possible to impart sharp melting properties to toner particles and ensure low-temperature fixability. On the other hand, if the toner particles contain a crystalline resin, the crystalline resin crystallizes within the toner image when the image is cooled after fixing. However, while the crystallization of the crystalline resin progresses during cooling, the crystallization of the crystalline resin does not progress sufficiently immediately after the toner image is fixed. On the other hand, when the fixed image comes into contact with a contact member such as a recording medium transport roll or a post-processing machine, the adhesion between the contact member and the fixed image increases, and the contact member is rapidly cooled. When the fixed image is cooled rapidly by contact with the contact member, the cooling rate differs between the area where the contact member is not in contact with the area where the contact member is in contact with the fixed image, resulting in a difference in the crystallization state of the crystalline resin. This is thought to be because the crystallization state of the crystalline resin changes depending on the cooling rate when crossing the freezing point of the crystalline resin. This causes a difference in gloss in the fixed image, resulting in a gloss step.

[0018] In contrast, in the toner according to this embodiment, the ratio of the loss tangent tanδ(80) / tanδ(60) of the toner particles at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C is reduced, and the loss tangent tanδ(80) at a temperature of 80°C is set within the above range. This reduces the contact state of the fixed image with components such as recording medium transport rolls and post-processing equipment, and suppresses crystallization of the crystalline resin due to the cooling rate when crossing the freezing point of the crystalline resin. However, if the loss tangent tanδ(80) at a temperature of 80°C is too large, toner deformation at high temperatures will be suppressed, impairing low-temperature fixability.

[0019] In addition, when the toner melts during fixing, the external additive sinks into the toner particles. The location of the external additive from the surface of the fixed image varies depending on the specific gravity and particle size of the external additive. When inorganic particles with the above specific gravity are used as the external additive, the external additive is more likely to be located in the surface layer of the fixed image. This allows the external additive to suppress crystallization of the crystalline resin in the surface layer of the fixed image, and the filler effect of the external additive provides elastic properties. As a result, the fixed image more significantly reduces contact with contacting members such as recording medium transport rolls and post-processing machines, and suppresses crystallization of the crystalline resin due to the cooling rate when crossing the freezing point of the crystalline resin.

[0020] These phenomena make it difficult for gloss differences to occur in the fixed image, and gloss step differences are suppressed.

[0021] From the above, it is presumed that the toner according to this embodiment can form an image in which the gloss difference is suppressed.

[0022] The toner according to this embodiment will be described in detail below. The toner according to this embodiment includes toner particles and an external additive.

[0023] (Dynamic viscoelasticity of toner particles) In dynamic viscoelasticity measurement of toner particles when the temperature is lowered from 110°C to 30°C, the ratio of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), is 0.90 or more and 1.40 or less, and preferably 1.10 or more and 1.30 or less.

[0024] If the ratio tan δ(80) / tan δ(60) is less than 0.90 or exceeds 1.40, the crystallization state of the crystalline resin is likely to change, causing a gloss difference.

[0025] In dynamic viscoelasticity measurement of the toner particles when the temperature is lowered from 110° C. to 30° C., the loss tangent tanδ(80) at a temperature of 80° C. is 1.20 or more and 1.70 or less, and preferably 1.30 or more and 1.60 or less.

[0026] If the loss tangent tan δ(80) at a temperature of 80° C. is less than 1.20, the toner tends to be suppressed from deforming at high temperatures, and low-temperature fixability is impaired. If the loss tangent tanδ(80) at a temperature of 80° C. exceeds 1.70, the toner tends to adhere to the contact member after fixing, the crystallization state of the crystalline resin tends to change, and a gloss difference occurs.

[0027] Methods for setting the ratio tanδ(80) / tanδ(60) and the loss tangent tanδ(80) at a temperature of 80°C within the above ranges include: 1) a method of adding internally added crosslinked resin particles (particularly internally added crosslinked resin particles having a specific glass transition temperature) to toner particles; and 2) a method of adjusting the amount of one or more metal ions selected from the group consisting of Al, Mg, and Ca in the toner particles to control the amount of crosslinking of the binder resin by the metal ions.

[0028] The loss tangent tan δ of the toner particles is measured by dynamic viscoelasticity measurement using a rheometer when the temperature is lowered from 110° C. to 30° C., and specifically, it is as follows. The toner particles to be measured are molded into tablets at room temperature (25°C) using a press molding machine to prepare a measurement sample. This measurement sample is set in the measuring machine and left at 120°C for 20 minutes. Thereafter, dynamic viscoelasticity measurement is carried out under the following measurement conditions, and the loss tangent tanδ at each temperature is obtained from the obtained curves of storage modulus and loss modulus. -Measurement conditions- Measurement device: Rheometer ARES (manufactured by TA Instruments) Measurement jig: 8mm parallel plate Gap: Adjusted to 3mm Frequency: 6.28rad / s Heating conditions: starting temperature = room temperature (e.g., 25°C), ending temperature = 120°C, heating rate = 2°C / min Temperature cooling conditions: Start temperature = 120℃, End temperature = 30℃, Cooling rate = 2℃ / min

[0029] Since the loss tangent tan δ of the toner particles at each temperature is not affected by the external additive, the loss tangent tan δ may be measured at each temperature by performing dynamic viscoelasticity measurement on the toner.

[0030] (Composition of toner particles) The toner particles contain an amorphous resin and a crystalline resin as binder resins, and may contain a colorant, a release agent, internally added crosslinked resin particles, and other additives. In particular, it is preferable that the toner particles contain internally crosslinked resin particles, since this makes it easier to obtain the loss tangent characteristics.

[0031] -Binder resin- The binder resin may be an amorphous resin or a crystalline resin. However, from the viewpoint of ensuring low-temperature fixability and suppressing gloss unevenness, the content of the crystalline resin relative to the binder resin is preferably 2% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 35% by mass or less, even more preferably 10% by mass or more and 30% by mass or less, and particularly preferably 15% by mass or more and 30% by mass or less.

[0032] The "crystalline" nature of a resin refers to the presence of a clear endothermic peak rather than a stepwise change in endothermic heat in differential scanning calorimetry (DSC). Specifically, this refers to the half-width of the endothermic peak being within 10°C when measured at a heating rate of 10°C / min. On the other hand, the term "amorphous" for a resin means that the half-width exceeds 10°C, that the endothermic amount exhibits a stepwise change, or that no clear endothermic peak is observed.

[0033] The amorphous resin will be described. Examples of amorphous resins include vinyl resins made of homopolymers of monomers such as styrenes (e.g., styrene, parachlorostyrene, α-methylstyrene, etc.), (meth)acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), and olefins (e.g., ethylene, propylene, butadiene, etc.), or copolymers of two or more of these monomers. Examples of amorphous resins include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosin, mixtures of these with the vinyl resins, and graft polymers obtained by polymerizing vinyl monomers in the presence of these. These amorphous resins may be used alone or in combination of two or more.

[0034] The amorphous resin is preferably an amorphous polyester resin from the viewpoint of ensuring low-temperature fixability. Examples of the amorphous polyester resin include a condensation polymer of a polycarboxylic acid and a polyhydric alcohol. Note that, as the amorphous polyester resin, a commercially available product or a synthesized product may be used.

[0035] Examples of polycarboxylic acids include aliphatic dicarboxylic acids (such as oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, and sebacic acid), alicyclic dicarboxylic acids (such as cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalenedicarboxylic acid), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). Among these, aromatic dicarboxylic acids are preferred as polycarboxylic acids. The polycarboxylic acid may be a trivalent or higher carboxylic acid having a crosslinked or branched structure in combination with a dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). The polycarboxylic acids may be used alone or in combination of two or more.

[0036] Examples of polyhydric alcohols include aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc.), and aromatic diols (e.g., ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, preferred polyhydric alcohols are aromatic diols and alicyclic diols, and more preferred are aromatic diols. As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked or branched structure may be used in combination with the diol. Examples of trihydric or higher polyhydric alcohols include glycerin, trimethylolpropane, and pentaerythritol. The polyhydric alcohols may be used alone or in combination of two or more.

[0037] The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50°C or higher and 80°C or lower, and more preferably 50°C or higher and 65°C or lower. The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), more specifically, from the "extrapolated glass transition onset temperature" described in JIS K 7121-1987 "Method for measuring transition temperatures of plastics."

[0038] The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less. The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less. The weight-average molecular weight and number-average molecular weight are measured by gel permeation chromatography (GPC). Molecular weight measurements by GPC are performed using a Tosoh GPC HLC-8120GPC measuring device and a Tosoh TSKgel SuperHM-M (15 cm) column in THF solvent. The weight-average molecular weight and number-average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared with monodisperse polystyrene standard samples.

[0039] The amorphous polyester resin can be obtained by a known manufacturing method, for example, by carrying out the reaction at a polymerization temperature of 180°C or higher and 230°C or lower, reducing the pressure in the reaction system as necessary, and removing water and alcohol generated during the condensation. If the raw material monomer is not soluble or compatible at the reaction temperature, a high-boiling solvent may be added as a solubilizer to dissolve it. In this case, the polycondensation reaction is carried out while distilling off the solubilizer. If a monomer with poor compatibility is present, it is advisable to first condense the poorly compatible monomer with the acid or alcohol to be polycondensed, and then polycondense the monomer with the main component.

[0040] Here, the amorphous resin may be used alone or in combination of two or more kinds. For example, it is preferable to use two or more amorphous polyesters having different molecular weights in combination as the amorphous polyester resin. An example of the use of two types in combination is the combination of a low molecular weight amorphous polyester resin (L-form) and a high molecular weight amorphous polyester resin (H-form). The low molecular weight (L-form) is preferably an amorphous polyester resin having a weight average molecular weight measured by GPC of 9000 to 20000. If the molecular weight is lower than 9000, offset tends to occur at high temperatures, while if the molecular weight is 20000 or higher, gloss is difficult to achieve at low temperatures. High molecular weight (H) polymers have a weight average molecular weight of 25,000 to 70,000 as measured by GPC. The following amorphous polyester resins are preferred: If the molecular weight is 70,000 or more, it becomes difficult to obtain gloss in high temperature areas, and the fixing temperature becomes high. The acid value of the non-crystalline polyester resin used in combination is preferably about 13 mgKOH / g or more and 20 mgKOH / g or less for low molecular weight (L-form) and about 10 mgKOH / g or more and 15 mgKOH / g or less for high molecular weight (H-form).

[0041] The crystalline resin will now be described. Examples of the crystalline resin include known crystalline resins such as crystalline polyester resins and crystalline vinyl resins (e.g., polyalkylene resins, long-chain alkyl (meth)acrylate resins, etc.) Among these, crystalline polyester resins are preferred from the viewpoint of ensuring low-temperature fixability.

[0042] The crystalline polyester resin may be, for example, a polycondensate of a polycarboxylic acid and a polyhydric alcohol. Note that, as the crystalline polyester resin, a commercially available product or a synthesized product may be used. Here, the crystalline polyester resin is preferably a polycondensate using a polymerizable monomer having a linear aliphatic group rather than a polymerizable monomer having an aromatic group, since it easily forms a crystalline structure.

[0043] Examples of polycarboxylic acids include aliphatic dicarboxylic acids (e.g., oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalene-2,6-dicarboxylic acid), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). The polycarboxylic acid may be a tricarboxylic or higher carboxylic acid having a crosslinked or branched structure in combination with a dicarboxylic acid. Examples of the tricarboxylic acid include aromatic carboxylic acids (e.g., 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.), anhydrides thereof, and lower alkyl esters thereof (e.g., having 1 to 5 carbon atoms). As the polycarboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids. The polycarboxylic acids may be used alone or in combination of two or more.

[0044] Examples of polyhydric alcohols include aliphatic diols (for example, straight-chain aliphatic diols having 7 to 20 carbon atoms in the main chain). Examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,14-eicosanedecanediol. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferred as aliphatic diols. The polyhydric alcohol may be a trihydric or higher alcohol having a crosslinked or branched structure, such as glycerin, trimethylolethane, trimethylolpropane, or pentaerythritol, in combination with the diol. The polyhydric alcohols may be used alone or in combination of two or more.

[0045] Here, the polyhydric alcohol has an aliphatic diol content of 80 mol % or more, preferably 90 mol % or more.

[0046] The melting temperature of the crystalline polyester resin is preferably 50°C or higher and 100°C or lower, more preferably 55°C or higher and 90°C or lower, and even more preferably 60°C or higher and 80°C or lower. The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC) by using the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperatures of plastics."

[0047] The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

[0048] The crystalline polyester resin can be obtained by a known manufacturing method, for example, in the same manner as the amorphous polyester.

[0049] The content of the binder resin is, for example, preferably 40% by mass to 95% by mass, more preferably 50% by mass to 90% by mass, and even more preferably 60% by mass to 85% by mass, based on the total mass of the toner particles.

[0050] -Coloring agent- Examples of colorants include carbon black, chrome yellow, Hansa Yellow, benzidine yellow, threne yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, Balkan orange, watch young red, permanent red, brilliant carmine 3B, brilliant carmine 6B, DuPont oil red, pyrazolone red, lithol red, rhodamine B lake, lake red C, pigment red, rose bengal, aniline blue, ultramarine blue, and the like. Examples of the dyes include various pigments such as phosphorus blue, chalco oil blue, methylene blue chloride, phthalocyanine blue, pigment blue, phthalocyanine green, and malachite green oxalate, and various dyes such as acridine-based, xanthene-based, azo-based, benzoquinone-based, azine-based, anthraquinone-based, thioindigo-based, dioxazine-based, thiazine-based, azomethine-based, indigo-based, phthalocyanine-based, aniline black-based, polymethine-based, triphenylmethane-based, diphenylmethane-based, and thiazole-based dyes. The colorant may be used alone or in combination of two or more kinds.

[0051] The colorant may be surface-treated as needed, or may be used in combination with a dispersant. Furthermore, a plurality of colorants may be used in combination.

[0052] The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less, based on the total mass of the toner particles.

[0053] -Mold release agent- Examples of release agents include hydrocarbon waxes, natural waxes such as carnauba wax, rice wax, and candelilla wax, synthetic or mineral / petroleum waxes such as montan wax, and ester waxes such as fatty acid esters and montanic acid esters, but are not limited thereto.

[0054] The melting temperature of the release agent is preferably 50°C or higher and 110°C or lower, and more preferably 60°C or higher and 100°C or lower. The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC) by using the "melting peak temperature" as described in the method for determining the melting temperature in JIS K 7121-1987 "Method for measuring transition temperatures of plastics."

[0055] The content of the release agent is, for example, 1% by mass or more and 20% by mass or less with respect to the total amount of the toner particles. The content is preferably 5% by mass or less and more preferably 5% by mass or more and 15% by mass or less.

[0056] -Internally added crosslinked resin particles- The internally added crosslinked resin particles are resin particles contained inside the toner particles, and refer to resin particles having a crosslinked structure between specific atoms in the polymer structure of the resin particles. The internally added crosslinked resin particles are, for example, particles that exist in the toner particles in a state in which they are incompatible with the binder resin.

[0057] Examples of the internally crosslinked resin particles include crosslinked resin particles crosslinked by ionic bonds (i.e., ionic crosslinked particles), crosslinked resin particles crosslinked by covalent bonds (i.e., covalently crosslinked resin particles), etc. Among these, crosslinked resin particles crosslinked by covalent bonds are preferred as the internally crosslinked resin particles.

[0058] Examples of resins used in the internally crosslinked resin particles include polyolefin resins (polyethylene, polypropylene, etc.), styrene resins (polystyrene, α-polymethylstyrene, etc.), (meth)acrylic resins (polymethyl methacrylate, polyacrylonitrile, etc.), epoxy resins, polyurethane resins, polyurea resins, polyamide resins, polycarbonate resins, polyether resins, polyester resins, and copolymer resins thereof. These resins may be used alone or in combination of two or more types, as needed.

[0059] Among the above resins, the resin used for the internally crosslinked resin particles includes a styrene-(meth)acrylic copolymer. Specifically, the resin particles contain 50% by mass or more of a styrene-(meth)acrylic copolymer as a main component, preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably substantially all of the styrene-(meth)acrylic copolymer. Furthermore, as the monomers constituting the copolymer, the total of styrene-based monomers and (meth)acrylic monomers is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more. The remainder is a crosslinking agent, which will be described later.

[0060] Examples of the styrene-(meth)acrylic copolymer include resins obtained by radical polymerization of the following styrene monomers and (meth)acrylic monomers.

[0061] Examples of styrene-based monomers include styrene, α-methylstyrene, vinylnaphthalene, alkyl-substituted styrenes having alkyl chains such as 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, and 4-ethylstyrene, halogen-substituted styrenes such as 2-chlorostyrene, 3-chlorostyrene, and 4-chlorostyrene, and fluorine-substituted styrenes such as 4-fluorostyrene and 2,5-difluorostyrene, etc. Among these, styrene and α-methylstyrene are preferred.

[0062] Examples of (meth)acrylic monomers include (meth)acrylic acid, n-methyl (meth)acrylate, n-ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, n-lauryl (meth)acrylate, n-tetradecyl (meth)acrylate, n-hexadecyl (meth)acrylate, and (meth) n-Octadecyl acrylate, isopropyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isopentyl (meth)acrylate, amyl (meth)acrylate, neopentyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, phenyl (meth)acrylate, biphenyl (meth)acrylate, diphenylethyl (meth)acrylate, t-butylphenyl (meth)acrylate, (meth)acrylate Examples thereof include terphenyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, methoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-carboxyethyl (meth)acrylate, (meth)acrylonitrile, (meth)acrylamide, etc. Among these, n-butyl (meth)acrylate and 2-carboxyethyl (meth)acrylate are preferred.

[0063] Examples of crosslinking agents for crosslinking the resin in the internally crosslinked resin particles include aromatic polyvalent vinyl compounds such as divinylbenzene and divinylnaphthalene; polyvalent vinyl esters of aromatic polyvalent carboxylic acids such as divinyl phthalate, divinyl isophthalate, divinyl terephthalate, divinyl homophthalate, divinyl trimesate, trivinyl trimesate, divinyl naphthalenedicarboxylate, and divinyl biphenylcarboxylate; divinyl esters of nitrogen-containing aromatic compounds such as divinyl pyridinedicarboxylate; vinyl esters of unsaturated heterocyclic carboxylic acids such as vinyl pyromethane, vinyl furancarboxylate, vinyl pyrrole-2-carboxylate, and vinyl thiophenecarboxylate; butanediol diacrylate, butanediol dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, octanediol diacrylate, octanediol dimethacrylate, nonanediol diacrylate, nonanediol dimethacrylate, decanediol diacrylate, decanediol diacrylate, (Meth)acrylic acid esters of linear polyhydric alcohols such as dodecanediol dimethacrylate, dodecanediol diacrylate, and dodecanediol dimethacrylate; (meth)acrylic acid esters of branched or substituted polyhydric alcohols such as neopentyl glycol dimethacrylate and 2-hydroxy, 1,3-diacryloxypropane; polyethylene glycol di(meth)acrylate, polypropylene polyethylene glycol di(meth)acrylates, divinyl succinate, divinyl fumarate, and maleic acid Examples of the crosslinking agent include polyvalent vinyl esters of polyvalent carboxylic acids such as vinyl, divinyl maleate, divinyl diglycolate, vinyl itaconate, divinyl itaconate, divinyl acetonedicarboxylate, divinyl glutarate, divinyl 3,3'-thiodipropionate, divinyl trans-aconitate, trivinyl trans-aconitate, divinyl adipate, divinyl pimelate, divinyl suberate, divinyl azelaate, divinyl sebacate, divinyl dodecanedioate, and divinyl brassylate. One type of crosslinking agent may be used alone, or two or more types may be used in combination.

[0064] Among these, it is preferable to use a bifunctional alkyl acrylate having an alkylene chain with 6 or more carbon atoms as the crosslinking agent for crosslinking the resin. That is, it is preferable that the internally crosslinked resin particles have a bifunctional alkyl acrylate as a constituent unit, and that the alkylene chain in the bifunctional alkyl acrylate has 6 or more carbon atoms. By using internally-added crosslinked resin particles having a bifunctional alkyl acrylate as a structural unit and an alkylene chain with 6 or more carbon atoms, it becomes easier to obtain a toner that undergoes a moderate range of toner deformation during fixing and has particularly good low-temperature fixing properties. If the crosslinking density of the internally-added crosslinked resin particles is high (i.e., the distance between crosslinking points is short), the elasticity becomes too high, whereas if a bifunctional acrylate having a long alkylene chain is used as the crosslinking agent, the crosslinking density becomes low (i.e., the distance between crosslinking points is long), and it is possible to prevent the elasticity of the internally-added crosslinked resin particles from becoming too high.

[0065] From the viewpoint of adjusting the crosslink density within an appropriate range, the number of carbon atoms in the alkylene chain in the bifunctional alkyl acrylate is preferably 6 or more, more preferably 6 to 12, and even more preferably 8 to 12. More specific bifunctional alkyl acrylates include 1,6-hexanediol acrylate, 1,6-hexanediol methacrylate, 1,8-octanediol diacrylate, 1,8-octanediol dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, 1,10 1,10-decanediol diacrylate, 1,10-decanediol dimethacrylate, 1,12-dodecanediol diacrylate, and 1,12-dodecanediol dimethacrylate are listed, and among these, 1,10-decanediol diacrylate and 1,10-decanediol dimethacrylate are preferred. Other examples of crosslinking agents include 2-carboxyethyl acrylate, and it is preferable to use at least one of these together with the above-mentioned bifunctional alkyl acrylate.

[0066] When the internally crosslinked resin particles are polymer particles of a resin particle-forming composition containing a styrene-based monomer, a (meth)acrylic monomer, and a crosslinking agent, the fixability of the internally crosslinked resin particles may be controlled by adjusting the amount of crosslinking agent contained in the composition. For example, increasing the amount of crosslinking agent contained in the composition makes it easier to obtain internally crosslinked resin particles with good fixability. The content of the crosslinking agent in the internally crosslinked resin particle-forming composition is, for example, preferably 0.3 to 5.0 parts by mass, more preferably 0.5 to 3.0 parts by mass, and even more preferably 0.8 to 2.5 parts by mass, per 100 parts by mass of the total of the styrene-based monomer, the (meth)acrylic monomer, and the crosslinking agent.

[0067] The glass transition temperature Tg(E) of the internally crosslinked resin particles is preferably 0°C or higher and 40°C or lower, more preferably 10°C or higher and 35°C or lower. By setting the glass transition temperature Tg(E) of the internally added crosslinked resin particles within the above range, it becomes easier to control the loss tangent tanδ of the toner particles at each temperature within the above range. As a result, gloss variations are easily suppressed. In addition, low-temperature fixability is improved.

[0068] The glass transition temperature Tg(E) of the internally crosslinked resin particles is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, is determined from the "extrapolated glass transition onset temperature" described in the method for determining glass transition temperatures in JIS K 7121-1987 "Method for measuring transition temperatures of plastics." The internally added crosslinked resin particles can be extracted from the toner by dissolving the toner in a solvent in which the binder resin is soluble, such as tetrahydrofuran (THF), recovering the insoluble matter, and then drying the recovered matter.

[0069] In the internally crosslinked resin particles made of a styrene-(meth)acrylic copolymer, the Tg(E) can be adjusted by adjusting the polymerization conditions of the copolymer. In particular, to obtain resin particles in which a composition gradient occurs within the internally crosslinked resin particles and regions rich in styrene units are unevenly distributed on the surface, it is preferable to increase the styrene monomer to (meth)acrylic monomer content ratio in the monomer-containing liquid as the polymerization progresses when producing the resin particles by polymerization of a monomer-containing liquid containing a styrene monomer and a (meth)acrylic monomer. "Increasing as the polymerization progresses" typically refers to gradually increasing the styrene monomer content ratio in the monomer-containing liquid, but also includes operations such as gradually increasing the styrene monomer content in the additional monomer when adding additional monomer to the monomer-containing liquid in multiple installments, or gradually increasing the styrene monomer concentration in the monomer-containing liquid by increasing the amount of added styrene monomer. For example, when preparing a styrene-(meth)acrylic copolymer by emulsion polymerization, the styrene monomer content in the emulsion can be gradually increased by adding the emulsion dropwise multiple times. Furthermore, it is also possible to control the progress of the reaction by adjusting the polymerization temperature, polymerization time, the method of adding the polymerization initiator, and the like.

[0070] The content of the internally added crosslinked resin particles is preferably 2% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less, based on the total mass of the toner. By setting the content of the internally added crosslinked resin particles within the above range, the loss of the toner particles at each temperature can be reduced. The tangent tanδ can be easily controlled within the above range, which makes it easier to suppress gloss variations and improves low-temperature fixability.

[0071] The average dispersed diameter of the internally added crosslinked resin particles is preferably 50 nm or more and 300 nm or less, more preferably 80 nm or more and 300 nm or less, and even more preferably 100 nm or more and 250 nm or less. When the average dispersed diameter of the internally added crosslinked resin particles is within the above range, it becomes easier to control the loss tangent tanδ of the toner particles at each temperature within the above range, which makes it easier to suppress gloss variations and improves low-temperature fixability.

[0072] The average dispersed diameter of the internally added crosslinked resin particles is measured as follows. Toner particles or toner are mixed and embedded in epoxy resin, and the epoxy resin is solidified. The solidified material is cut using an ultramicrotome (Leica Ultracut UCT) to prepare thin section samples with thicknesses of 80 nm to 130 nm. The resulting thin section samples are then stained with ruthenium tetroxide for 3 hours in a desiccator at 30°C. SEM images of the stained thin section samples are then obtained using an ultra-high-resolution field emission scanning electron microscope (FE-SEM, Hitachi High-Technologies Corporation, S-4800). The release agent, styrene-(meth)acrylic resin, and polyester resin are stained with ruthenium tetroxide in this order, so each component is identified by the shade resulting from the degree of staining. If the shade is difficult to distinguish due to the condition of the sample, the staining time can be adjusted. In the cross section of a toner particle, the colorant domain is smaller than the release agent domain and the resin particle domain, and therefore they are distinguished by size. In the SEM image, 30 toner cross sections whose maximum length is 85% or more of the volume average particle diameter of the toner particles are selected, and a total of 100 dyed internally-added crosslinked resin particles (i.e., their domains) are observed. The maximum length of each domain is measured, and the maximum length is considered to be the diameter of the domain. The diameters are arithmetically averaged to determine the average circular equivalent diameter. The obtained average circular equivalent diameter is then used as the average dispersed diameter of the internally-added crosslinked resin particles.

[0073] The average dispersion diameter of the internally added crosslinked resin particles can be adjusted by, for example, producing toner particles by aggregation and coalescence and adjusting the volume average particle diameter of the internally added crosslinked resin particles contained in the internally added crosslinked resin particle dispersion liquid used during production; or by preparing a plurality of internally added crosslinked resin particle dispersion liquids with different volume average particle diameters and using them in combination; or the like.

[0074] -Method of manufacturing internally crosslinked resin particles- As a method for producing the internally crosslinked resin particles, known methods such as emulsion polymerization, melt kneading using a Banbury mixer or a kneader, suspension polymerization, and spray drying can be applied. However, emulsion polymerization is preferred in order to unevenly distribute units derived from a styrene-based monomer on the particle surface. In the method for producing the internally crosslinked resin particles, it is preferable to use a styrene-based monomer and a (meth)acrylic-based monomer as the monomers and polymerize them in the presence of a crosslinking agent. In the method for producing the internally crosslinked resin particles, it is preferable to carry out emulsion polymerization multiple times.

[0075] The method for producing the internally crosslinked resin particles will be described in more detail below. The method for producing the internally crosslinked resin particles includes the steps of: a step of obtaining an emulsion containing a monomer, a crosslinking agent, a surfactant, and water (emulsion preparation step); a step of adding a polymerization initiator to the emulsion and heating the emulsion to polymerize the monomers (first emulsion polymerization step); a step (second emulsion polymerization step) of adding an emulsion containing a monomer and a crosslinking agent to the reaction solution after the first emulsion polymerization step and heating the mixture to polymerize the monomer; It is preferred that it contains Furthermore, in the second emulsion polymerization step, in order to adjust the composition of the particle surface, a styrene-based monomer and The emulsion may be prepared by changing the ratio of the (meth)acrylic monomer, and then added multiple times.

[0076] --Emulsion preparation process-- This is a step of obtaining an emulsion containing a monomer, a crosslinking agent, a surfactant, and water. It is preferable to obtain an emulsion by emulsifying the monomer, crosslinking agent, surfactant, and water using an emulsifier. Examples of emulsifiers include rotary agitators equipped with propeller-type, anchor-type, paddle-type, or turbine-type agitating blades; static mixers such as static mixers; rotor-stator emulsifiers such as homogenizers and Clearmix; mill-type emulsifiers equipped with a grinding function; high-pressure emulsifiers such as Manton-Gaulin pressure emulsifiers; high-pressure nozzle-type emulsifiers that generate cavitation under high pressure; high-pressure collision-type emulsifiers such as microfluidizers that apply shear force by causing liquids to collide with each other under high pressure; ultrasonic emulsifiers that generate cavitation using ultrasound; and membrane emulsifiers that emulsify through fine pores.

[0077] As the monomer, it is preferable to use a styrene-based monomer and a (meth)acrylic-based monomer. As the crosslinking agent, those already mentioned above are applicable.

[0078] Examples of surfactants include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Nonionic surfactants may be used in combination with anionic surfactants or cationic surfactants. Among these, anionic surfactants are preferred. The surfactants may be used alone or in combination of two or more.

[0079] The emulsion may contain a chain transfer agent. There are no particular limitations on the chain transfer agent, but a compound having a thiol component can be used. Specifically, alkyl mercaptans such as hexyl mercaptan, heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan, and dodecyl mercaptan are preferred. The mass ratio of the styrene-based monomer to the (meth)acrylic monomer in the emulsion (styrene-based monomer / (meth)acrylic monomer) is preferably 0.2 or more and 1.1 or less. The content of the crosslinking agent in the entire emulsion is preferably 0.5% by mass or more and 3% by mass or less.

[0080] --First emulsion polymerization step-- This is a process in which a polymerization initiator is added to the emulsion and heated to polymerize the monomers. Here, when carrying out the polymerization, it is preferable to stir the emulsion (reaction solution) containing the polymerization initiator with a stirrer. Examples of the agitator include rotary agitators equipped with propeller-type, anchor-type, paddle-type, or turbine-type agitator blades. As the polymerization initiator, ammonium persulfate is preferably used.

[0081] --Second emulsion polymerization step-- This is a step in which an emulsion containing a monomer is added to the reaction solution after the first emulsion polymerization step, and the mixture is heated to polymerize the monomer. During the polymerization, it is preferable to stir the reaction solution in the same manner as in the first emulsion polymerization step. In this step, the emulsion containing the monomers may be added in multiple portions by changing the ratio of the styrene-based monomer to the (meth)acrylic monomer in the emulsion. The emulsion containing the monomer is preferably obtained by emulsifying the monomer, surfactant, and water using an emulsifier, for example.

[0082] -Other additives- Examples of other additives include well-known additives such as magnetic materials, charge control agents, inorganic powders, etc. These additives are contained in the toner particles as internal additives.

[0083] -Characteristics of toner particles, etc.- The toner particles preferably contain one or more metal ions selected from the group consisting of Al, Mg, and Ca. The ratio AV1 / M1 of the amount M1 of the metal ions to the acid value AV1 of the binder resin is 1.0×10 3 Over 4.0 x 10 3 Less than 1.5 x 10 is preferable. 3 Over 3.8 x 10 3 Less than 2.0 x 10 is preferable. 3 Over 3.5 x 10 3The following is even more preferred: By setting the ratio AV1 / M1 within the above range, an appropriate crosslinking structure is imparted to the binder resin, making it easier to control the loss tangent tanδ of the toner particles within the above range. As a result, edge contamination of the recording medium is more easily suppressed. In addition, low-temperature fixability is improved. The amount of metal ions is preferably 0.001% by mass or more and 0.020% by mass or less, and more preferably 0.002% by mass or more and 0.010% by mass or less, based on the toner particles.

[0084] Examples of metal ion sources (compounds to be contained in toner particles as additives) include metal salts, inorganic metal salt polymers, metal complexes, etc. These metal salts and inorganic metal salt polymers are added to toner particles as aggregating agents, for example, when toner particles are produced by an aggregation-coalescence method. Examples of metal salts include aluminum sulfate, aluminum chloride, magnesium chloride, magnesium sulfate, calcium chloride, and calcium sulfate. Examples of inorganic metal salt polymers include polyaluminum chloride and polyaluminum hydroxide. Examples of suitable inorganic fillers include calcium carbonate, calcium polysulfide, and the like. Examples of the metal complex include metal salts of aminocarboxylic acids, etc. Specific examples of the metal complex include metal salts (e.g., calcium salts, magnesium salts, aluminum salts, etc.) based on known chelates such as ethylenediaminetetraacetic acid, propanediaminetetraacetic acid, nitriletriacetic acid, triethylenetetraminehexaacetic acid, and diethylenetriaminepentaacetic acid.

[0085] The source of these metal ions may be added simply as an additive, rather than as a flocculant.

[0086] As the metal ion, Al ions are preferred. That is, as the source of metal ions, aluminum salts (e.g., aluminum sulfate, aluminum chloride, etc.) and aluminum salt polymers (e.g., polyaluminum chloride, polyaluminum hydroxide, etc.) are preferred. Among the sources of metal ions, inorganic metal salt polymers are particularly preferred. Therefore, as the source of metal ions, aluminum salt polymers (e.g., polyaluminum chloride, polyaluminum hydroxide, etc.) are particularly preferred.

[0087] The amount of metal ions is measured by quantitatively analyzing the fluorescent X-ray intensity of the toner particles. Specifically, for example, a resin and a metal ion source are first mixed to obtain a resin mixture with a known metal ion concentration. 200 mg of this resin mixture is then molded into a pellet sample using a tablet molder with a diameter of 13 mm. The mass of this pellet sample is precisely weighed, and the fluorescent X-ray intensity of the pellet sample is measured to determine the peak intensity. Similarly, measurements are also taken on pellet samples with different amounts of metal ion source added, and a calibration curve is created from these results. Then, using this calibration curve, the content of metal ions in the toner particles to be measured is calculated. In this embodiment, the metal ions are not limited to metals in an ionized state in the resin or toner particles, but refer to metal elements that can be measured as fluorescent X-ray intensity.

[0088] Examples of methods for adjusting the amount of metal ions include: 1) adjusting the amount of a metal ion source added; and 2) when toner particles are produced by an aggregation and coalescence method, adding an aggregating agent (e.g., a metal salt or a metal salt polymer) as a metal ion source in the aggregation step, and then adding a chelating agent (e.g., EDTA (ethylenediaminetetraacetic acid), DTPA (diethylenetriaminepentaacetic acid), NTA (nitrilotriacetic acid), etc.) at the end of the aggregation step to form a complex with the metal ions using the chelating agent, and then removing the formed complex salt in a subsequent washing step or the like to adjust the metal ion content.

[0089] The acid value of the binder resin is measured based on "JIS K 0070 1992 Testing methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter of chemical products." The binder resin can be extracted from the toner by dissolving the toner in a solvent in which the binder resin is soluble, such as tetrahydrofuran (THF), removing the insoluble matter, and then drying the toner.

[0090] The toner particles may be toner particles of a single layer structure, or may be toner particles of a so-called core-shell structure composed of a core part (core particle) and a coating layer (shell layer) that coats the core part. Here, the toner particles having a core-shell structure may preferably be composed of, for example, a core containing a binder resin, internally added crosslinked resin particles, and, if necessary, other additives such as a colorant and a release agent, and a coating layer containing a binder resin and internally added crosslinked resin particles.

[0091] The volume average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

[0092] The various average particle sizes and particle size distribution indices of the toner particles are measured using a Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte is measured using an ISOTON-II (manufactured by Beckman Coulter). For the measurement, 0.5 mg to 50 mg of the sample to be measured is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant, and this is then added to 100 ml to 150 ml of the electrolyte. The electrolyte solution containing the suspended sample is dispersed for 1 minute using an ultrasonic disperser, and the particle size distribution of particles with a particle size range of 2 μm to 60 μm is measured using a Coulter Multisizer II with an aperture diameter of 100 μm. The number of particles sampled is 50,000. Based on the particle size distribution measured, cumulative distributions of volume and number are drawn for each divided particle size range (channel) from the smallest diameter side, and the particle size at 16% of the cumulative total is defined as the volume particle size D16v, the number particle size D16p, the particle size at 50% of the cumulative total as the volume average particle size D50v, the cumulative number average particle size D50p, and the particle size at 84% of the cumulative total as the volume particle size D84v and the number particle size D84p. Using these, the volumetric particle size distribution index (GSDv) is (D84v / D16v) 1 / 2 , the number particle size distribution index (GSDp) is (D84p / D16p) 1 / 2 It is calculated as:

[0093] The average circularity of the toner particles is preferably 0.90 or more and 1.00 or less, and more preferably 0.92 or more and 0.98 or less.

[0094] The average circularity of toner particles is calculated by (circular equivalent perimeter) / (perimeter) [(perimeter of a circle having the same projected area as the particle image) / (perimeter of the particle projected image)]. Specifically, this value is measured by the following method. First, the toner particles to be measured are sucked and collected, forming a flat flow, and then instantly The particle image is captured as a still image by emitting light, and the particle image is analyzed using a flow particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation). The number of samples taken to calculate the average circularity is 3,500. When the toner contains external additives, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additives have been removed.

[0095] (external additives) The external additive contains inorganic particles having a specific gravity of 1.3 to 2.0 (hereinafter also referred to as "inorganic particles SG") The specific gravity of the inorganic particles SG is preferably 1.35 to 1.90, more preferably 1.40 to 1.80. Here, the specific gravity of the inorganic particles SG indicates the specific gravity of all inorganic particles that are externally added to the toner particles as external additives.

[0096] If the specific gravity of the inorganic particles SG as an external additive is less than 1.3, the inorganic particles tend to separate from the toner particles when the toner image is fixed. If the specific gravity of the inorganic particles SG as an external additive exceeds 2.0, when the toner particles are melted during fixation of the toner image, the inorganic particles tend to sink excessively into the interior of the toner particles. Therefore, it becomes difficult to exhibit the function of the inorganic particles to suppress crystallization of the crystalline resin and the function of the inorganic particles to more elastically control the toner image surface due to their filler effect, making it difficult to suppress gloss unevenness.

[0097] The specific gravity of the inorganic particles SG is a true specific gravity, and is measured using a Le Chatelier pycnometer in accordance with 5-2-1 of JIS-K-0061:92. Specifically, the measurement is carried out in the following manner. (0) 40 mL of 0.2% Triton X-100 aqueous solution (manufactured by Acros Oranics) and 2 g of toner were placed in a 200 mL glass bottle and stirred 500 times to disperse the toner. The dispersion was then subjected to ultrasonic waves using an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho, US-300AT). The ultrasonic waves were applied continuously for 6000 seconds, with an output of 75 W, an amplitude of 180 μm, and a distance of 10 mm between the ultrasonic vibrator and the bottom of the container. The dispersion was then centrifuged at 3000 rpm for 2 minutes at a cooling temperature of 0°C using a small, high-speed refrigerated centrifuge (manufactured by Sakuma Seisakusho, M201-IVD). The supernatant was collected and dried. Solvents with different specific gravities were prepared, and the resulting powder was immersed in the solvent and centrifuged to obtain the target inorganic particle SG. The resulting inorganic particle SG was used as the sample. (1) Pour approximately 250 ml of ethyl alcohol into the Le Chatelier pycnometer and adjust so that the meniscus is at the scale. (2) Immerse the pycnometer in a constant temperature water bath, and when the liquid temperature reaches 20.0±0.2°C, accurately read the position of the meniscus on the pycnometer's scale (accuracy 0.025 ml). (3) Weigh out approximately 100,000 g of sample and let its mass be W. (4) Place the weighed sample in a density bottle and remove any bubbles. (5) Immerse the pycnometer in a constant temperature water bath, and when the liquid temperature reaches 20.0±0.2°C, accurately read the position of the meniscus on the pycnometer's scale (accuracy 0.025 ml).

[0098] After the above operations (0) to (5) are performed, the specific gravity is then calculated based on the following formulas (1) and (2). Formula: D=W / (L2-L1) ·Formula: S=D / 0.9982 where D is the density of the sample (20°C) (g / cm 3 ), S is the specific gravity of the sample (20°C), W is the apparent mass of the sample (g), L1 is the meniscus reading (ml) at a liquid temperature of 20°C before the sample is placed in the pycnometer, and L2 is the meniscus reading (ml) at a liquid temperature of 20°C after the sample is placed in the pycnometer. The constant "0.9982" in equation (2) represents the density of water at 20°C (g / cm 3 )

[0099] The volume average particle size of the inorganic particles SG as an external additive is preferably 30 nm or more and 80 nm or less, more preferably 35 nm or more and 75 nm or less, and even more preferably 40 nm or more and 70 nm or less. When the volume average particle diameter of the inorganic particles SG as an external additive is within the above range, the inorganic particles are less likely to detach from the toner particles when the toner image is fixed, and are more likely to sink into the surface of the toner particles when the toner particles are melted. This makes it easier for the inorganic particles to suppress the crystallization of the crystalline resin and to more elastically control the toner image surface due to their filler effect. As a result, it becomes easier to suppress gloss unevenness.

[0100] The volume average particle size of the inorganic particles SG as an external additive is measured as follows. The toner is imaged at 40,000 magnification using a scanning electron microscope (SEM) (e.g., S-4700 manufactured by Hitachi High-Technologies Corporation), and observed at an acceleration voltage of 15 kV, an emission current of 20 μA, and a working distance of 15 mm. The identified inorganic particles SG are then analyzed using image processing analysis software WinRoof (manufactured by Mitani Corporation). The circle-equivalent diameters of at least 200 particles are measured, and the particle size that is 50% cumulative from the smallest diameter side in the volume-based particle size distribution is determined as the volume-average particle size of the inorganic particles SG.

[0101] Inorganic particles SG as external additives include SiO2, TiO2, Al2O3, SrTiO3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, K2O·(TiO2) n , Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, MgSO4, etc. Among these, it is preferable to use silica particles (wet silica particles such as sol-gel silica particles, gas-phase silica particles such as fumed silica particles), titania particles, alumina particles, etc. as the inorganic particles SG, and silica particles (particularly sol-gel silica particles) are more preferable.

[0102] Here, when the inorganic particles SG are silica particles, known silica particle manufacturing methods can be used. However, since it is impossible or difficult to control the true specific gravity to 2.0 or less in processes involving high-temperature firing, such as the vapor phase oxidation method shown in Patent Document 16, JP 2004-102236 A, it is preferable to use a sol-gel method, which enables low-temperature synthesis. Although calcination is often performed in the sol-gel method, it is particularly preferable not to perform calcination before the surface treatment step when producing silica particles, because it is easy to control the true specific gravity to 2.0 or less. That is, it is particularly preferable that the silica is produced using the sol-gel method, and that the maximum process temperature during production is 75°C or less. Furthermore, in order to control the true specific gravity to 2.0 or less, it is preferable that a solvent with a high boiling point remains in the silica gel during the drying step. Therefore, it is preferable to use an alcohol with a high boiling point as the solvent, and 2-propanol, tert-butyl alcohol, etc. are more preferable. Furthermore, using N,N-dimethylformaldehyde or formaldehyde as a drying solvent, or adding a small amount of such, can inhibit gel shrinkage and reduce the true specific gravity.

[0103] The surfaces of the inorganic particles SG as external additives are preferably subjected to a hydrophobic treatment. The hydrophobic treatment is carried out, for example, by immersing the inorganic particles in a hydrophobic treatment agent. The hydrophobic treatment agent is not particularly limited, but examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used alone or in combination of two or more. The amount of the hydrophobic treatment agent is usually, for example, 1 part by mass per 100 parts by mass of inorganic particles. or more and 10 parts by mass or less.

[0104] Examples of external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), cleaning agents (for example, metal salts of higher fatty acids such as zinc stearate, and particles of fluorine-based polymers).

[0105] The amount of the inorganic particles SG as an external additive is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.5% by mass or more and 7% by mass or less, based on the toner particles. The total amount of external additives added is preferably 0.01% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 6.0% by mass or less, based on the toner particles.

[0106] Here, from the viewpoint of ensuring low-temperature fixability and suppressing gloss unevenness, the ratio of the content of the crystalline resin to the amount of the inorganic particles SG added externally (amount of the inorganic particles SG added externally / content of the crystalline resin) is 1.0×10 -2 Over 10.0 x 10 -2 Less than 2.0 x 10 is preferable. -2 Over 8.0 x 10 -2 The following is more preferred:

[0107] (Toner manufacturing method) Next, a method for producing the toner according to this embodiment will be described. The toner according to this exemplary embodiment is obtained by producing toner particles and then externally adding an external additive to the toner particles.

[0108] The toner particles may be produced by any of a dry production method (for example, a kneading and pulverization method) and a wet production method (for example, an aggregation and coalescence method, a suspension polymerization method, a dissolution and suspension method). The method for producing the toner particles is not particularly limited, and any well-known production method may be used. Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

[0109] Specifically, for example, when toner particles are produced by an aggregation and coalescence method, for example, a step of mixing a first amorphous resin particle dispersion liquid in which first amorphous resin particles to be a binder resin are dispersed, a crystalline resin particle dispersion liquid in which crystalline resin particles to be a binder resin are dispersed, an internally crosslinked resin particle dispersion liquid in which internally crosslinked resin particles are dispersed, a colorant dispersion liquid in which a colorant is dispersed, and a release agent particle dispersion liquid in which release agent particles (hereinafter also referred to as "release agent particles") are dispersed, and aggregating the particles and the colorant in the obtained dispersion liquid to form first aggregated particles (first aggregated particle forming step); a step of adding second amorphous resin particles, which serve as a binder resin, to the first aggregated particle dispersion liquid after obtaining the first aggregated particle dispersion liquid in which the first aggregated particles are dispersed, to aggregate the second amorphous resin particles onto the surfaces of the first aggregated particles, thereby forming second aggregated particles (second aggregated particle forming step); a step of heating the second aggregate particle dispersion liquid in which the second aggregate particles are dispersed to fuse and coalesce the second aggregate particles to form toner particles (fusion and coalescence step); Toner particles are produced through the above steps. The aggregation-coalescence method will be described as a method for producing toner particles containing a binder resin, a colorant, and a release agent, but the colorant and release agent are components that are contained in the toner particles as needed.

[0110] Each step will be described in detail below.

[0111] -Each dispersion preparation process- First, the various dispersions to be used in the aggregation-coalescence method are prepared. Specifically, a first amorphous resin particle dispersion in which a first amorphous resin serving as a binder resin is dispersed, a crystalline resin particle dispersion in which crystalline resin particles are dispersed, an internally crosslinked resin particle dispersion in which internally crosslinked resin particles are dispersed, a colorant dispersion in which a colorant is dispersed, a second amorphous resin particle dispersion in which second amorphous resin particles serving as a binder resin are dispersed, and a release agent particle dispersion in which release agent particles are dispersed are prepared. In each dispersion preparation step, the first amorphous resin, the second amorphous resin particles, and the crystalline resin particles will be referred to as "resin particles" in the following description.

[0112] Here, the resin particle dispersion liquid is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

[0113] Examples of the dispersion medium used in the resin particle dispersion include aqueous media. Examples of aqueous media include water such as distilled water and ion-exchanged water, alcohols, etc. These may be used alone or in combination of two or more.

[0114] Examples of surfactants include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly preferred. Nonionic surfactants may be used in combination with anionic surfactants or cationic surfactants. The surfactants may be used alone or in combination of two or more.

[0115] In the resin particle dispersion, resin particles can be dispersed in a dispersion medium by a general dispersion method such as a rotary shear homogenizer, a ball mill having a medium, a sand mill, a dyno mill, etc. Depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion by, for example, a phase inversion emulsification method. The phase inversion emulsification method involves dissolving the resin to be dispersed in a hydrophobic organic solvent in which the resin is soluble, adding a base to the organic continuous phase (O phase) to neutralize it, and then adding an aqueous medium (W phase), thereby converting the resin from W / O to O / W (so-called phase inversion) and forming a discontinuous phase, and dispersing the resin in particulate form in the aqueous medium.

[0116] The volume average particle size of the resin particles dispersed in the resin particle dispersion is, for example, preferably from 0.01 μm to 1 μm, more preferably from 0.08 μm to 0.8 μm, and even more preferably from 0.1 μm to 0.6 μm. The volume average particle size of the resin particles is measured using a particle size distribution obtained by measurement with a laser diffraction particle size distribution analyzer (e.g., LA-700 manufactured by Horiba, Ltd.), and the cumulative distribution for the volume of the divided particle size range (channel) is subtracted from the small particle size side, and the particle size at which the cumulative 50% of all particles is measured is defined as the volume average particle size D50v. The volume average particle sizes of particles in other dispersions are also measured in the same way.

[0117] The content of resin particles contained in the resin particle dispersion is, for example, preferably from 5% by mass to 50% by mass, and more preferably from 10% by mass to 40% by mass.

[0118] Note that, in the same manner as in the resin particle dispersion, for example, a colorant dispersion, a release agent particle dispersion, and an internally-added crosslinked resin particle dispersion are also prepared. That is, the volume average particle size, dispersion medium, dispersion method, and particle content of the particles in the resin particle dispersion are the same for the colorant dispersed in the colorant dispersion, the release agent particles dispersed in the release agent particle dispersion, and the internally-added crosslinked resin particles dispersed in the internally-added crosslinked resin particle dispersion.

[0119] -First agglomerated particle formation process- Next, the first amorphous resin particle dispersion, the crystalline resin particle dispersion, the internally crosslinked resin particle dispersion, the colorant dispersion, and the release agent particle dispersion are mixed together. Then, in this mixed dispersion, the first amorphous resin, the crystalline resin particles, the internally added crosslinked resin particles, the colorant, and the release agent particles are hetero-aggregated to form first aggregated particles containing the first amorphous resin, the internally added crosslinked resin particles, the colorant, and the release agent particles.

[0120] Specifically, for example, a first amorphous resin particle dispersion, a crystalline resin particle dispersion, an internally crosslinked resin particle dispersion, a colorant dispersion, and a release agent particle dispersion are mixed together, and an aggregating agent is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to be acidic (for example, a pH of 2 or more and 5 or less), a dispersion stabilizer is added as needed, and then the temperature is set to a range of 20°C or more and 50°C or less, and the particles dispersed in the mixed dispersion are aggregated to form first aggregated particles. In the first aggregate particle formation step, for example, the mixed dispersion may be stirred with a rotary shear homogenizer, the aggregating agent may be added at room temperature (e.g., 25°C), the pH of the mixed dispersion may be adjusted to an acidic value (e.g., a pH of 2 or more and 5 or less), a dispersion stabilizer may be added as needed, and then the heating may be carried out.

[0121] Examples of the flocculant include a surfactant having a polarity opposite to that of the surfactant used as the dispersant added to the mixed dispersion, an inorganic metal salt, and a divalent or higher metal complex. In particular, when a metal complex is used as the flocculant, the amount of surfactant used can be reduced and the charging characteristics can be improved. If necessary, an additive that forms a complex or a similar bond with the metal ions of the flocculant may be used, and a chelating agent is preferably used as this additive.

[0122] Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, as well as inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. The chelating agent may be a water-soluble chelating agent, such as hydroxycarboxylic acid (e.g., tartaric acid, citric acid, gluconic acid), iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), etc. The amount of the chelating agent added is preferably 0.01 to 5.0 parts by mass, more preferably 0.1 to less than 3.0 parts by mass, per 100 parts by mass of resin particles (amorphous resin particle dispersion and crystalline resin particles).

[0123] -Second agglomerated particle formation process- Next, after obtaining the first aggregated particle dispersion liquid in which the first aggregated particles are dispersed, the second amorphous resin particle dispersion liquid in which the second amorphous resin particles are dispersed is added to the first aggregated particle dispersion liquid. The second amorphous resin particles may be of the same type as the first amorphous resin, or may be of a different type.

[0124] Then, in the dispersion of the first aggregated particles and the second amorphous resin particles, the second amorphous resin particles are aggregated on the surfaces of the first aggregated particles. At this time, a release agent particle dispersion may also be added to aggregate the second amorphous resin particles and the release agent particles on the surfaces of the first aggregated particles. Specifically, for example, in the first aggregated particle forming step, when the first aggregated particles reach a target particle size, the second amorphous resin particle dispersion is added to the first aggregated particle dispersion, and the mixture is heated at a temperature equal to or lower than the glass transition temperature of the second amorphous resin particles. Then, the pH of the dispersion is adjusted to, for example, a range of about 6.5 to 8.5, thereby stopping the progress of aggregation. In this manner, the second aggregated particles are obtained by aggregating the first aggregated particles so that the second amorphous resin particles adhere to the surfaces of the first aggregated particles.

[0125] -Fusion / unification process- Next, the second aggregate particle dispersion liquid in which the second aggregate particles are dispersed is heated, for example, to a temperature equal to or higher than the glass transition temperature of the first and second amorphous resin particles (for example, a temperature 10 to 30°C higher than the glass transition temperature of the first and second resin particles) to fuse and coalesce the second aggregate particles and form toner particles.

[0126] Through the above steps, toner particles are obtained. In the above-described aggregation and coalescence method, the first aggregated particles may be fused and coalesced to form toner particles without performing the second aggregated particle forming step. Also, the second aggregated particle forming step may be repeatedly performed multiple times. In the second aggregate particle forming step, a crystalline resin particle dispersion may be used, or an internally crosslinked resin particle dispersion may be used.

[0127] After the fusion and coalescence process, the toner particles formed in the solution are subjected to a known washing process, a solid-liquid separation process, and a drying process to obtain dry toner particles. In the washing step, it is preferable to carry out sufficient replacement washing with ion-exchanged water from the viewpoint of electrostatic chargeability. Furthermore, the solid-liquid separation step is not particularly limited, but from the viewpoint of productivity, it is preferable to carry out suction filtration, pressure filtration, etc. Furthermore, in the drying step, there is no particular limitation on the method, but from the viewpoint of productivity, it is preferable to carry out freeze drying, flash drying, fluidized drying, vibration-type fluidized drying, etc.

[0128] The toner according to this embodiment is produced by, for example, adding an external additive to the obtained dry toner particles and mixing them. The mixing can be carried out using, for example, a V blender, a Henschel mixer, a Loedige mixer, or the like. Furthermore, if necessary, coarse particles may be removed from the toner using a vibrating sieve, an air sieve, or the like.

[0129] <Electrostatic image developer> The electrostatic image developer according to this embodiment contains at least the toner according to this embodiment. The electrostatic image developer according to this embodiment may be a one-component developer containing only the toner according to this embodiment, or may be a two-component developer containing the toner and a carrier mixed therewith.

[0130] The carrier is not particularly limited, and examples thereof include known carriers, such as coated carriers in which the surface of a core material made of magnetic powder is coated with a coating resin, magnetic powder dispersion carriers in which magnetic powder is dispersed and blended in a matrix resin, and resin-impregnated carriers in which porous magnetic powder is impregnated with a resin. The magnetic powder dispersion type carrier and the resin impregnated type carrier may be a carrier in which the constituent particles of the carrier are used as a core material and are coated with a coating resin.

[0131] Examples of magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

[0132] Examples of coating resins and matrix resins include styrene-(meth)acrylic acid resins; polyolefin resins such as polyethylene resins and polypropylene resins; polyvinyl or polyvinylidene resins such as polystyrene, (meth)acrylic resins, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, and polyvinyl ketone; vinyl chloride-vinyl acetate copolymers; straight silicone resins or modified silicone resins consisting of organosiloxane bonds; fluororesins such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, and polychlorotrifluoroethylene; polyesters; polyurethanes; polycarbonates; amino resins such as urea-formaldehyde resins; and epoxy resins. The coating resin and the matrix resin preferably contain a (meth)acrylic resin, more preferably contain 50% by mass or more of the (meth)acrylic resin relative to the total mass of the resin, and even more preferably contain 80% by mass or more of the (meth)acrylic resin relative to the total mass of the resin. In particular, the coating resin and the matrix resin preferably contain an alicyclic (meth)acrylic resin as the (meth)acrylic resin. The coating resin and the matrix resin may contain other additives such as conductive particles. Examples of conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

[0133] Here, the method of coating the surface of the core material with a coating resin includes a method of coating with a solution for forming a coating layer in which the coating resin and, if necessary, various additives are dissolved in an appropriate solvent. The solvent is not particularly limited and may be selected taking into consideration the coating resin to be used, its applicability, etc. Specific resin coating methods include an immersion method in which the core material is immersed in a solution for forming a coating layer, a spray method in which the solution for forming a coating layer is sprayed onto the surface of the core material, a fluidized bed method in which the solution for forming a coating layer is sprayed onto the core material while it is suspended in flowing air, and a kneader coater method in which the core material of the carrier and the solution for forming a coating layer are mixed in a kneader coater and the solvent is removed.

[0134] In the two-component developer, the mixing ratio (mass ratio) of toner to carrier is preferably toner:carrier=1:100 to 30:100, and more preferably 3:100 to 20:100.

[0135] <Image forming device / image forming method> An image forming apparatus and an image forming method according to this embodiment will be described. The image forming apparatus according to the present embodiment includes an image carrier, a charging device that charges the surface of the image carrier, an electrostatic image forming device that forms an electrostatic image on the surface of the charged image carrier, a developing device that contains an electrostatic image developer and develops the electrostatic image formed on the surface of the image carrier as a toner image using the electrostatic image developer, a transfer device that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing device that fixes the toner image transferred to the surface of the recording medium. The electrostatic image developer according to the present embodiment is used as the electrostatic image developer.

[0136] The image forming apparatus according to this embodiment carries out an image forming method (the image forming method according to this embodiment) that includes a charging step of charging the surface of an image carrier, an electrostatic image forming step of forming an electrostatic image on the surface of the charged image carrier, a developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image using the electrostatic image developer according to this embodiment, a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0137] The image forming apparatus according to the present embodiment may be any of known image forming apparatuses, such as a direct transfer type apparatus that directly transfers a toner image formed on the surface of an image carrier to a recording medium; an intermediate transfer type apparatus that primarily transfers a toner image formed on the surface of an image carrier to the surface of an intermediate transfer medium, and then secondarily transfers the toner image transferred to the surface of the intermediate transfer medium to the surface of a recording medium; an apparatus equipped with a cleaning device that cleans the surface of the image carrier after the transfer of the toner image but before charging; and an apparatus equipped with a static elimination device that irradiates the surface of the image carrier with static elimination light to eliminate static after the transfer of the toner image but before charging. In the case of an intermediate transfer type device, the transfer device is configured to have, for example, an intermediate transfer body onto whose surface a toner image is transferred, a primary transfer device that performs primary transfer of the toner image formed on the surface of the image carrier onto the surface of the intermediate transfer body, and a secondary transfer device that performs secondary transfer of the toner image transferred onto the surface of the intermediate transfer body onto the surface of the recording medium.

[0138] In the image forming apparatus according to the present embodiment, for example, the portion including the developing device may have a cartridge structure (process cartridge) that is detachably attached to the image forming apparatus. As the process cartridge, for example, a process cartridge equipped with a developing device that accommodates the electrostatic image developer according to the present embodiment is preferably used.

[0139] An example of an image forming apparatus according to the present embodiment will be described below, but the present invention is not limited to this. Note that only the main parts shown in the drawings will be described, and descriptions of other parts will be omitted.

[0140] FIG. 1 is a schematic diagram showing the configuration of an image forming apparatus according to this embodiment. The image forming apparatus shown in Fig. 1 includes first through fourth electrophotographic image forming units 10Y, 10M, 10C, and 10K that output images in the colors yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. These image forming units (hereinafter sometimes simply referred to as "units") 10Y, 10M, 10C, and 10K are arranged side by side horizontally spaced a predetermined distance apart from one another. Note that these units 10Y, 10M, 10C, and 10K may also be process cartridges that are detachable from the image forming apparatus.

[0141] Above each of the units 10Y, 10M, 10C, and 10K in the drawing, an intermediate transfer belt 20 serving as an intermediate transfer body extends through each unit. The intermediate transfer belt 20 is wound around a drive roll 22 and a support roll 24 that are spaced apart from each other and arranged from left to right in the drawing, and is configured to run in a direction from the first unit 10Y to the fourth unit 10K. Note that a force is applied to the support roll 24 in a direction away from the drive roll 22 by a spring or the like (not shown), thereby applying tension to the intermediate transfer belt 20 wound around them. In addition, an intermediate transfer body cleaning device 30 is provided on the outer circumferential surface of the intermediate transfer belt 20, facing the drive roll 22. In addition, the developing devices (examples of developing devices) 4Y, 4M, 4C, and 4K of each unit 10Y, 10M, 10C, and 10K are each supplied with toner including four colors of toner: yellow, magenta, cyan, and black, contained in toner cartridges 8Y, 8M, 8C, and 8K.

[0142] Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, the first unit 10Y, which forms a yellow image and is disposed upstream in the direction of travel of the intermediate transfer belt, will be described here as a representative. Note that parts equivalent to those of the first unit 10Y are given reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y), and descriptions of the second to fourth units 10M, 10C, and 10K will be omitted.

[0143] The first unit 10Y has a photoreceptor 1Y that acts as an image carrier. Around the photoreceptor 1Y, there are arranged in this order: a charging roll (an example of a charging device) 2Y that charges the surface of the photoreceptor 1Y to a predetermined potential; an exposure device (an example of an electrostatic image forming device) 3 that exposes the charged surface to a laser beam 3Y based on a color-separated image signal to form an electrostatic image; a developing device (an example of a developing device) 4Y that supplies charged toner to the electrostatic image to develop it; a primary transfer roll (an example of a primary transfer device) 5Y that transfers the developed toner image onto the intermediate transfer belt 20; and a photoreceptor cleaning device (an example of a cleaning device) 6Y that removes toner remaining on the surface of the photoreceptor 1Y after the primary transfer. The primary transfer roll 5Y is disposed inside the intermediate transfer belt 20 and is positioned opposite the photoreceptor 1Y. Furthermore, a bias power supply (not shown) that applies a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power supply varies the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

[0144] The operation of forming a yellow image in first unit 10Y will be described below. First, prior to operation, the surface of the photosensitive member 1Y is charged to a potential of −600V to −800V by the charging roll 2Y. The photoconductor 1Y has conductivity (for example, volume resistivity at 20°C: 1×10 -6 The photosensitive layer is formed by laminating a photosensitive layer on a substrate with a resistivity of Ωcm or less. This photosensitive layer normally has a high resistance (the resistance of ordinary resins), but when irradiated with a laser beam 3Y, the resistivity of the irradiated portion changes. Therefore, a laser beam 3Y is output to the charged surface of the photosensitive element 1Y via an exposure device 3 in accordance with image data for yellow sent from a control unit (not shown). The laser beam 3Y is irradiated onto the photosensitive layer on the surface of the photosensitive element 1Y, thereby forming an electrostatic charge image of a yellow image pattern on the surface of the photosensitive element 1Y.

[0145] An electrostatic image is an image formed on the surface of the photosensitive element 1Y by charging it; the laser beam 3Y reduces the resistivity of the irradiated portion of the photosensitive layer, causing the charged charges on the surface of the photosensitive element 1Y to flow, while the charges remain in the portions not irradiated by the laser beam 3Y, forming a so-called negative latent image. The electrostatic image formed on the photoreceptor 1Y is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic image on the photoreceptor 1Y is made visible as a toner image (developed image) by the developing device 4Y.

[0146] The developing device 4Y contains an electrostatic image developer containing, for example, at least yellow toner and a carrier. The yellow toner is frictionally charged by stirring inside the developing device 4Y and is held on a developer roll (an example of a developer holder) with a charge of the same polarity (negative polarity) as the charge on the photoreceptor 1Y. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner electrostatically adheres to the discharged latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. The photoreceptor 1Y with the yellow toner image formed thereon continues to travel at a predetermined speed, and the toner image developed on the photoreceptor 1Y is transported to a predetermined primary transfer position.

[0147] When the yellow toner image on the photoreceptor 1Y is transported to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoreceptor 1Y to the primary transfer roll 5Y acts on the toner image, causing the toner image on the photoreceptor 1Y to be transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a (+) polarity opposite to the (-) polarity of the toner, and in the first unit 10Y, for example, it is controlled to +10 μA by a control unit (not shown). On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the photoreceptor cleaning device 6Y.

[0148] Furthermore, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K of the second unit 10M and subsequent units is also controlled in accordance with the first unit. In this way, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is conveyed sequentially through the second to fourth units 10M, 10C, and 10K, and the toner images of each color are transferred onto the intermediate transfer belt 20 in a superimposed manner.

[0149] The intermediate transfer belt 20, onto which the four-color toner images have been multiplex-transferred through the first to fourth units, reaches a secondary transfer section composed of the intermediate transfer belt 20, a support roll 24 in contact with the inner surface of the intermediate transfer belt, and a secondary transfer roll (an example of a secondary transfer device) 26 arranged on the outer circumferential surface of the intermediate transfer belt 20. Meanwhile, recording paper (an example of a recording medium) P is fed via a feed mechanism into the gap between the secondary transfer roll 26 and the intermediate transfer belt 20 at a predetermined timing, and a secondary transfer bias is applied to the support roll 24. The transfer bias applied at this time has a negative polarity, the same as the negative polarity of the toner. Electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, transferring the toner image on the intermediate transfer belt 20 onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection device (not shown) that detects the resistance of the secondary transfer section, and is voltage-controlled.

[0150] Thereafter, the recording paper P is sent to the pressure contact portion (nip portion) of a pair of fixing rolls in a fixing device (an example of a fixing device) 28, where the toner image is fixed onto the recording paper P, forming a fixed image.

[0151] Examples of the recording paper P onto which the toner image is transferred include plain paper used in electrophotographic copying machines, printers, etc. In addition to the recording paper P, examples of the recording medium include overhead projector sheets and the like. To further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth. For example, coated paper in which the surface of plain paper is coated with resin or the like, or art paper for printing, is preferably used.

[0152] The recording paper P on which the color image has been fixed is conveyed toward the discharge section, and the series of color image forming operations is completed.

[0153] <Process cartridges / toner cartridges> The process cartridge according to this embodiment will be described. The process cartridge according to this embodiment is a process cartridge that is detachably attached to an image forming apparatus and that contains the electrostatic image developer according to this embodiment and is equipped with a developing device that develops an electrostatic image formed on the surface of an image carrier using the electrostatic image developer into a toner image.

[0154] The process cartridge according to this embodiment is not limited to the above configuration, but may also be configured to include a developing device and, if necessary, at least one other device selected from an image carrier, a charging device, an electrostatic image forming device, and a transfer device.

[0155] An example of a process cartridge according to the present embodiment will be described below, but the present invention is not limited to this. Note that only the main parts shown in the drawings will be described, and descriptions of other parts will be omitted.

[0156] FIG. 2 is a schematic diagram showing the configuration of the process cartridge according to the present embodiment. The process cartridge 200 shown in FIG. 2 is configured to integrally combine and hold a photosensitive member 107 (an example of an image carrier), a charging roll 108 (an example of a charging device) provided around the photosensitive member 107, a developing device 111 (an example of a developing device), and a photosensitive member cleaning device 113 (an example of a cleaning device), which are held by a housing 117 having, for example, a mounting rail 116 and an opening 118 for exposure, and is formed into a cartridge. In FIG. 2, 109 denotes an exposure device (an example of an electrostatic image forming device), 112 denotes a transfer device (an example of a transfer device), 115 denotes a fixing device (an example of a fixing device), and 300 denotes recording paper (an example of a recording medium).

[0157] Next, the toner cartridge according to this embodiment will be described. The toner cartridge according to the present embodiment is a toner cartridge that contains the toner according to the present embodiment and is detachably attached to an image forming apparatus. The toner cartridge contains replenishment toner to be supplied to a developing device provided in the image forming apparatus.

[0158] 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8M, 8C, and 8K can be attached and detached, and developing devices 4Y, 4M, 4C, and 4K are connected to the toner cartridges corresponding to each developing device (color) by toner supply pipes (not shown). When the toner stored in a toner cartridge runs low, the toner cartridge is replaced. [Example]

[0159] Examples will be described below, but the present invention is not limited to these examples. In the following description, unless otherwise specified, all "parts" and "%" are by mass.

[0160] [Preparation of emulsions (1-1 to 1-2)] <Emulsion (1-1)> Styrene: 80 parts n-Butyl acrylate: 120 parts 1,10-decanediol diacrylate (crosslinking agent): 4.0 parts Anionic surfactant (Newcol 271A, manufactured by Nippon Nyukazai Co., Ltd.): 2.2 parts Ion-exchanged water: 197.8 parts The above materials were placed in a mixing vessel equipped with a stirrer and stirred to prepare an emulsion (1-1).

[0161] <Emulsion (1-2)> Styrene: 75 parts n-Butyl acrylate: 25 parts 1,10-decanediol diacrylate (crosslinking agent): 1.0 part Anionic surfactant (Newcol 271A): 1.1 parts Ion-exchanged water: 97.7 parts The above materials were placed in a mixing vessel equipped with a stirrer and stirred to prepare an emulsion (1-1).

[0162] [Preparation of Internally Added Crosslinked Resin Particle Dispersion (1)] A reaction vessel equipped with a stirrer and a nitrogen inlet tube was purged with nitrogen, and then 1.1 parts of anionic surfactant (Eleminol MON-2) and 400 parts of ion-exchanged water were added. The reaction solution was heated in an oil bath with stirring until the temperature of the reaction solution reached 75°C. 10 parts of emulsion (1-1) were added, followed by 20 parts of an aqueous ammonium persulfate solution adjusted to a concentration of 10% by mass, and the mixture was maintained for 30 minutes. Thereafter, while maintaining the temperature of the reaction solution at 75°C, 190 parts of emulsion (1-1) was gradually added dropwise to the reaction vessel over 30 minutes using a pump. 200 parts of emulsion (1-2) were then added dropwise over 30 minutes. Subsequently, 200 parts of emulsion (1-3) were added dropwise over 40 minutes, and 200 parts of emulsion (1-4) were then added dropwise over 40 minutes. After the dropwise addition, the mixture was held for 60 minutes, and then 2 parts of 10% by mass ammonium persulfate was added, and the mixture was held for another 3 hours, after which it was cooled to room temperature. Ion-exchanged water and nitric acid were then added to adjust the solid content to 20% by mass, to obtain an internally-added crosslinked resin particle dispersion (1). The resulting resin particles had a volume average particle size of 165 nm and a glass transition temperature of 17°C as measured by a differential scanning calorimeter.

[0163] [Preparation of Internally Added Crosslinked Resin Particle Dispersions (2) to (7)] Except for changing the conditions shown in Table 1, the same procedures as for the internally crosslinked resin particle dispersion (1) were carried out to prepare internally crosslinked resin particles (2) to (7).

[0164] [Preparation of amorphous polyester resin particle dispersion (1)] Terephthalic acid: 25 parts by mole Isophthalic acid: 19 molar parts Adipic acid: 3 molar parts Trimellitic anhydride: 2 molar parts Bisphenol A propylene oxide 2 mole adduct: 31 mole parts Bisphenol A propylene oxide 3 mole adduct: 20 mole parts The above materials were charged into a reaction vessel equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a distillation column, and the temperature was raised to 190°C over 1 hour, followed by adding 1.2 parts of dibutyltin oxide per 100 parts of the above materials. The temperature was raised to 240°C over 6 hours while distilling off the generated water, and then the temperature was maintained at 240°C for 3 hours to continue the dehydration condensation reaction, followed by cooling to obtain amorphous polyester resin (1). The amorphous polyester resin (1) had an acid value of 10, a glass transition temperature of 61°C, and a weight-average molecular weight of 25,000.

[0165] Amorphous polyester resin (1): 100 parts Methyl ethyl ketone: 60 parts Isopropanol: 10 parts 10% ammonia solution: 3.5 parts The above materials were charged into a jacketed reaction vessel equipped with a condenser, a thermometer, a water dropping device, and an anchor blade, and the amorphous polyester resin (1) was dissolved in a water-circulating thermostatic bath while stirring and mixing at 100 rpm while maintaining the liquid temperature at 50° C. Next, the water-circulating thermostatic bath was set to 40° C., and a total of 300 parts of ion-exchanged water maintained at 40° C. was added dropwise at a rate of 3 parts / min to cause phase inversion and produce an emulsion. The resulting emulsion was placed in a recovery flask and set in an evaporator equipped with a vacuum control unit via a trap bulb. The recovery flask was rotated and heated in a 60°C hot water bath, and the pressure was reduced to 7 kPa while taking care to prevent bumping, to remove the solvent. The pressure was then returned to normal pressure, and the recovery flask was water-cooled to obtain a dispersion. Ion-exchange water was added to the resulting dispersion to obtain an amorphous polyester resin particle dispersion (1) with a solids content of 20% by mass. The volume average particle size of the amorphous polyester resin particles in the amorphous polyester resin particle dispersion (1) was 180 nm.

[0166] [Preparation of amorphous polyester resin particle dispersions (2) to (7)] Amorphous polyester resin particle dispersions (2) to (7) were prepared in the same manner as for the amorphous polyester resin particle dispersion (1), except that the conditions were changed as shown in Table 2. The abbreviations in Table 2 represent the following compounds. TPA: Terephthalic acid IPA: Isophthalic acid TMA: Trimellitic anhydride BPA-2PO: Bisphenol A propylene oxide 2 mole adduct BPA-3PO: Bisphenol A propylene oxide 3 mole adduct BPA-2EO: Bisphenol A ethylene oxide 2 mole adduct

[0167] [Preparation of Crystalline Polyester Resin Particle Dispersion (1)] Dodecanedioic acid: 50 parts by mole 1,6-Hexanediol: 50 parts by mole The above materials were charged into a reaction vessel equipped with a stirrer, nitrogen inlet tube, temperature sensor, and distillation column. The temperature was raised to 160°C over 1 hour, and 0.8 parts of dibutyltin oxide was added per 100 parts of the above materials. The temperature was raised to 180°C over 6 hours while distilling off the generated water, and the reaction proceeded under reflux in the vessel while maintaining 180°C and stirring for 5 hours. The temperature was then gradually raised to 230°C under reduced pressure (3 kPa) and maintained at 230°C while stirring for 2 hours. The reaction mixture was then cooled. After cooling, solid-liquid separation was performed, and the solid was dried to obtain crystalline polyester resin (1). The acid value of crystalline polyester resin (1) was 8.8 and the weight-average molecular weight was 29,000.

[0168] Crystalline polyester resin (1): 100 parts Methyl ethyl ketone: 70 parts Isopropanol: 12 parts 10% ammonia solution: 3 parts The above materials were charged into a jacketed reaction vessel equipped with a condenser, a thermometer, a water dropping device, and an anchor blade, and the crystalline polyester resin (1) was dissolved by stirring and mixing at 100 rpm while maintaining the liquid temperature at 80° C. in a water circulation type thermostatic bath. Next, the water circulation type thermostatic bath was set to 60° C., and a total of 300 parts of ion-exchanged water maintained at 60° C. was added dropwise at a rate of 3 parts / min to cause phase inversion, thereby obtaining an emulsion. The resulting emulsion was placed in a recovery flask and set in an evaporator equipped with a vacuum control unit via a trap bulb. The recovery flask was rotated and heated in a 60°C hot water bath, and the pressure was reduced to 7 kPa while taking care to prevent bumping, to remove the solvent. The pressure was then returned to normal pressure, and the recovery flask was water-cooled to obtain a dispersion. Ion-exchange water was added to the dispersion to obtain a crystalline polyester resin particle dispersion (1) with a solids content of 20 mass%. The volume average particle size of the crystalline polyester resin particles in the crystalline polyester resin particle dispersion (1) was 160 nm.

[0169] [Preparation of colorant dispersion] Carbon black (Regel 330, manufactured by Cabot Corporation): 110 parts Anionic surfactant (Neopelex G-65, Kao Corporation): 6 parts Ion-exchanged water: 300 parts The above materials were mixed and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50, manufactured by IKA). Ion-exchanged water was added to the resulting dispersion to obtain a colorant particle dispersion with a solid content of 20% by mass. The volume average particle size of the colorant particles in the colorant dispersion was 220 nm.

[0170] [Preparation of release agent particle dispersion] Fischer-Tropsch wax (Sasolwax H1, Sasol): 100 parts Anionic surfactant (Neopelex G-65): 6 parts Ion-exchanged water: 300 parts The above materials were mixed and heated to 100°C, and dispersed using a homogenizer (Ultra Turrax T50). Further, the mixture was dispersed using a Manton-Gaulin high-pressure homogenizer (Gaulin), and ion-exchanged water was added to the dispersion to obtain a release agent particle dispersion with a solid content of 20% by mass. The volume average particle size of the release agent particles in the release agent particle dispersion was 230 nm.

[0171] [Preparation of external additives] (Preparation of External Additive (1)) Under a nitrogen atmosphere, a reaction vessel was charged with 80 parts of ethanol, 80 parts of 2-propanol, 6 parts of tetraethoxysilane, 6 parts of tert-butyldimethylchlorosilane, and 12 parts of distilled water. While stirring at 160 rpm, 14 parts of 20% aqueous ammonia was added dropwise over 4 minutes. After stirring at 30°C for 3.5 hours, the mixture was concentrated using an evaporator until the liquid volume was reduced to half. To this mixture, 10 parts of tert-butyl alcohol and 300 parts of distilled water were added, and the product was precipitated using a centrifugal settler. The supernatant was removed by decantation, and 300 parts of distilled water was added, followed by similar separation using a centrifugal settler. This process was repeated several times, after which the precipitate was freeze-dried in a freeze dryer for 2 days to obtain a white powder. 10 parts of this white powder was added to 300 parts of toluene and 1 part of HMDS, and the mixture was stirred at room temperature for 30 minutes using ultrasonic waves. The mixture was then concentrated to dryness and dried by heating at 120°C for 1 hour. The mixture was then added to 100 parts of HMDS, ultrasonically stirred at room temperature for 30 minutes, concentrated to dryness, and heated and dried at 120°C for 1 hour to obtain an external additive (1) made of silica particles. The external additive (1) had a specific gravity of 1.5 and a number-average particle size of 60 nm.

[0172] (Preparation of external additive (2)) External additive (2) was obtained in the same manner as external additive (1), except that tert-butyl alcohol was used instead of 2-propanol, 20 parts of 20% aqueous ammonia was added dropwise over 15 minutes while stirring at 180 rpm, and the amount of tert-butyl alcohol added after concentration was changed to 350 parts. The specific gravity of external additive (2) was 1.3, and the number-average particle size was 60 nm.

[0173] (Preparation of external additive (3)) External additive (3) was obtained in the same manner as external additive (1), except that 9 parts of tetraethoxysilane and 5 parts of diphenyldiethoxysilane were used in combination instead of tert-butyldimethylchlorosilane. The specific gravity of external additive (3) was 1.9, and the number average particle size was 60 nm.

[0174] (Preparation of external additive (4)) External additive (4) was obtained in the same manner as external additive (1), except that the stirring speed was changed from 160 rpm to 240 rpm and 20% aqueous ammonia was added dropwise over 60 minutes. The specific gravity of external additive (4) was 1.5 and the number-average particle size was 30 nm.

[0175] (Preparation of external additive (5)) An external additive (5) was obtained in the same manner as for external additive (1), except that the stirring rotation speed was changed from 160 rpm to 80 rpm. The specific gravity of external additive (5) was 1.5, and the number average particle size was 80 nm.

[0176] (Preparation of external additive (6)) External additive (6) was obtained in the same manner as external additive (1), except that the stirring speed was changed from 160 rpm to 300 rpm and 20% aqueous ammonia was added dropwise over 80 minutes. The specific gravity of external additive (6) was 1.5 and the number-average particle size was 25 nm.

[0177] (Preparation of external additive (7)) An external additive (7) was obtained in the same manner as for external additive (1), except that the stirring rotation speed was changed from 160 rpm to 50 rpm. The specific gravity of external additive (7) was 1.5, and the number average particle size was 84 nm.

[0178] (Preparation of external additive (8)) A monomer dispersion solution was obtained by mixing 100 parts of methyl methacrylate as a monomer, 1 part of ammonium persulfate as a polymerization initiator, 5.5 parts of sodium dodecylbenzenesulfonate as a suspension aid, and 200 parts of ion-exchanged water. The monomer dispersion solution was stirred at 70°C for 7 hours to obtain a suspension in which polymethyl methacrylate particles were dispersed in water. This suspension was dried to obtain an external additive (8) consisting of polymethyl methacrylate particles. The external additive (8) had a specific gravity of 1.2 and a number-average particle size of 60 nm.

[0179] (Preparation of external additive (9)) Commercially available fumed silica "RX50 (manufactured by Nippon Aerosil), true specific gravity = 2.2, sphericity Ψ = 0.58, volume average particle size D50 = 40 nm" was used as the external additive (9).

[0180] Examples of the properties of each external additive are shown in Table 3.

[0181] [Example 1] (Preparation of Toner 1) Amorphous polyester resin particle dispersion (1) (solid content 20% by mass): 61.7 parts ·Internally added crosslinked resin particle dispersion (1) (solid content 20% by mass): 10 parts Crystalline polyester resin particle dispersion (1) (solid content 20% by mass): 15.4 parts Colorant dispersion (solid content 20% by mass): 6.9 parts Release agent particle dispersion (solid content 20% by mass): 6 parts Anionic surfactant (Eleminol MON-2): 1.6 parts Ion-exchanged water: 80 parts The above materials were placed in a reaction vessel equipped with a thermometer, pH meter, and stirrer, and the temperature of the reaction vessel was maintained at 20°C while stirring at 150 rpm for 30 minutes. Next, a 0.3 N aqueous nitric acid solution was added to adjust the pH to 5.0, and then 12 parts of a 1% aqueous aluminum sulfate solution were added while dispersing with a homogenizer (Ultra-Turrax T50). Next, the temperature was raised to 45°C at a rate of 0.4°C / min while stirring, and the mixture was maintained for 30 minutes. Next, 29 parts of amorphous polyester resin particle dispersion (1) was added and the mixture was maintained for 30 minutes. Next, 0.62 parts of Chelest 40 (manufactured by Chelest Corporation, 40% content) was added. After that, a 0.1N aqueous sodium hydroxide solution was added to adjust the pH to 8.5 and maintained for 15 minutes. Then, while continuing to stir, the temperature was raised to 80°C at a rate of 1°C / min and maintained at 80°C for 5 hours. The mixture was then cooled, solid-liquid separated, and the solid matter was washed with ion-exchanged water. Then, the mixture was dried in a vacuum freeze dryer for 24 hours to obtain toner particles (1) having a volume average particle size of 5.5 μm. 100 parts of the toner particles (1) and 0.6 parts of the external additive (1) were mixed in a Henschel mixer to obtain toner 1.

[0182] [Examples 2 to 39 and Comparative Examples 1 to 6] (Preparation of Toners 2 to 39 and Toners C1 to C6) Toners 2 to 39 and toners C1 to C6 were obtained in the same manner as in the preparation of toner 1, except that the type and amount of each resin particle dispersion and the type and amount of external additive were changed as shown in Table 4. The solid content of each resin particle dispersion was 20% by mass. The post-added amorphous polyester resin particle dispersion was also changed as shown in Table 4.

[0183] The following items are shown for the toners obtained in Examples 1 to 39 and Comparative Examples 1 to 6. The methods for measuring the properties of the toners are as described above. Loss tangent tanδ(80) of toner particles at a temperature of 80°C Loss tangent tanδ(60) of toner particles at a temperature of 60°C Specific gravity and volume average particle size of inorganic particles SG as external additives Glass transition temperature Tg of internally crosslinked resin particles Crystalline resin content relative to binder resin MC1 The ratio of the crystalline resin content MCry1 to the externally added amount of inorganic particles SG MSG1 (externally added amount of inorganic particles MSG1 / crystalline resin content MCry1) Amount M1 of one or more metal ions selected from the group consisting of Al, Mg, and Ca in the toner particles The ratio of the amount of metal ions M1 to the acid value AV1 of the binder resin AV1 is AV1 / M1

[0184] [evaluation] (Preparation of developer) Developers were obtained by mixing 8 parts of each toner obtained in each example with 92 parts of the following carrier, and the obtained developers were used in the evaluations described below. (Creating the carrier) Ferrite particles (average particle size 35 μm): 100 parts Toluene: 14 parts Styrene / methyl methacrylate copolymer (copolymerization ratio 15 / 85): 3 parts Carbon black: 0.2 parts The above components except for the ferrite particles were dispersed in a sand mill to prepare a dispersion, and this dispersion was placed in a vacuum degassing kneader together with the ferrite particles, and the mixture was dried under reduced pressure while stirring to obtain a carrier.

[0185] (low temperature fixability) The resulting developer was loaded into the developing unit of a color copier, Apeos C6570 (manufactured by Fujifilm Business Innovation Co., Ltd.), with the fixing unit removed, and the toner loading was adjusted to 9.0 g / cm2, and an unfixed image was output. Colotech 90 paper (manufactured by Xerox, basis weight 90 gsm) was used as the recording medium. The output image was a 50 mm x 50 mm image with 100% image density. The unfixed image was then fixed using a fixing evaluation device to evaluate low-temperature fixability. The fixing device used was an Apeos C6570 manufactured by Fujifilm Business Innovation Co., Ltd., with the fixing unit removed and modified so that the fixing temperature could be changed. The fixing temperature was raised from 120°C to 190°C in 5°C increments, and the temperature at which no image defects due to offset (a phenomenon in which toner is not sufficiently melted and adheres to the fixing member) occurred was defined as the minimum fixing temperature, and was classified as follows: A: Minimum fixing temperature is 145°C or less B: Minimum fixing temperature is over 145°C and below 155°C C: Minimum fixing temperature is over 155℃ and below 165℃ D: Minimum fixing temperature is 165°C or higher

[0186] (Gross step) Each of the prepared developers was filled into the developing unit of a color production printer Revorias Press PC1120 (manufactured by Fujifilm Business Innovation Co., Ltd.) as an apparatus for image evaluation. An image was formed using an image evaluation device, with the fixing temperature set at the minimum fixing temperature +15°C. The paper used was mirror coated platinum paper 256 (A3 size), and the toner amount was 8.7 g / m 2 Ten consecutive images were printed with a width of 100mm, axially covering the entire surface, with a 2mm margin at the top, and with 100% image density. A gloss meter (manufactured by BYK; product name: Micro Trigloss) was used to measure the gloss at 20 points in the image area of ​​the 10th sheet, and the gloss difference within the paper was evaluated as the gloss difference. The evaluation criteria were as follows: A+: Gloss difference within the paper is less than 2 A: The gloss difference within the paper is 2 or more and less than 5 B: The gloss difference within the paper is 5 or more but less than 10 C: The gloss difference within the paper is 10 or more and less than 15 D: Gloss difference within the paper is 15 or more

[0187] [Table 1]

[0188] [Table 2]

[0189] [Table 3]

[0190] [Table 4-1]

[0191] [Table 4-2]

[0192] [Table 4-3]

[0193] From the above results, it can be seen that the toner of this example has low temperature fixability and can form an image with reduced gloss unevenness, compared to the toner of the comparative example.

[0194] This embodiment includes the following aspects. (((1))) The toner includes toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, the external additive contains inorganic particles having a specific gravity of 1.3 or more and 2.0 or less, The toner for developing electrostatic images has, in a dynamic viscoelasticity measurement of the toner particles when cooled from 110°C to 30°C, a ratio of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), of 0.90 or more and 1.40 or less, and the loss tangent tanδ(80) at a temperature of 80°C is 1.20 or more and 1.70 or less. (((2))) The toner for developing electrostatic images according to (((1))), wherein the volume average particle diameter of the inorganic particles is 30 nm or more and 80 nm or less. (((3))) The toner for developing electrostatic images according to (((1))) or <2))), wherein the toner particles contain internally added crosslinked resin particles. (((4))) The toner for developing electrostatic images according to (((3))), wherein the glass transition temperature Tg of the internally added crosslinked resin particles is 0° C. or higher and 40° C. or lower. (((5))) The ratio of the content of the crystalline resin to the external amount of the inorganic particles (external amount of inorganic particles / content of crystalline resin) is 1.0×10 -2 Over 10.0 x 10 -2The toner for developing electrostatic images according to any one of the following (((1))) to (((4))): (((6))) The ratio of the content of the crystalline resin to the externally added amount of the inorganic particles (externally added amount of inorganic particles / content of crystalline resin) is 2.0×10 -2 Over 8.0 x 10 -2 The toner for developing electrostatic images according to the following (((5))). (((7))) The toner for developing electrostatic images according to any one of (((1))) to (((6))), wherein the crystalline resin is a crystalline polyester resin. (((8))) The toner for developing electrostatic images according to any one of ((1))) to (((7))), wherein the content of the crystalline resin relative to the binder resin is 10% by mass or more and 30% by mass or less. (((9))) the toner particles contain one or more metal ions selected from the group consisting of Al, Mg, and Ca; The ratio AV1 / M1 of the amount M1 of the metal ions to the acid value AV1 of the binder resin is 1.0×10 3 Over 4.0 x 10 3 The toner for developing electrostatic images according to any one of the following (((1))) to (((8))): (((10))) The ratio AV1 / M1 of the amount M1 of the metal ions to the acid value AV1 of the binder resin is 2.0×10 3 Over 3.5 x 10 3 The toner for developing electrostatic images according to (((9))) below. (((11))) An electrostatic image developer comprising the toner for developing electrostatic images according to any one of (((1))) to (((10))). (((12))) The toner for developing electrostatic images according to any one of (((1))) to (((10))) is contained, A toner cartridge that is detachably attached to an image forming device. (((13))) a developing device that contains the electrostatic image developer according to (((11))) and develops an electrostatic image formed on the surface of an image carrier into a toner image by using the electrostatic image developer, A process cartridge is detachably mounted in an image forming apparatus. (((14))) an image carrier; a charging device that charges the surface of the image carrier; an electrostatic image forming device for forming an electrostatic image on the charged surface of the image carrier; a developing device that contains the electrostatic image developer according to (((11))) and develops the electrostatic image formed on the surface of the image carrier into a toner image by using the electrostatic image developer; a transfer device that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing device for fixing the toner image transferred onto the surface of the recording medium; An image forming apparatus comprising: (((15))) a charging step of charging the surface of the image carrier; an electrostatic image forming step of forming an electrostatic image on the charged surface of the image carrier; a developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image using the electrostatic image developer according to (((11))); a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing step of fixing the toner image transferred onto the surface of the recording medium; An image forming method comprising the steps of:

[0195] The effects of the above embodiment are as follows. According to the invention related to (((1))), there is provided an electrostatic image developing toner which has toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, and which can form an image with reduced gloss unevenness while maintaining low-temperature fixability, compared to when the inorganic particles used as the external additive have a specific gravity of less than 1.3 or more than 2.0, or when the toner particles have a ratio tanδ(80) / tanδ(60) of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), which is less than 0.9 or more than 1.40, in dynamic viscoelasticity measurement when the temperature is lowered from 110°C to 30°C, and the loss tangent tanδ(80) at a temperature of 80°C is less than 1.20 or more than 1.70. According to the invention related to (((2))), there is provided a toner for developing electrostatic images which has low-temperature fixing properties and can form images with reduced gloss unevenness, compared to when the volume average particle size of the inorganic particles is less than 30 nm or more than 80 nm.

[0196] According to the invention related to (((3))), there is provided a toner for developing electrostatic images which can form images with reduced gloss unevenness while having low-temperature fixability compared to toner particles which do not contain internally added crosslinked resin particles. According to the invention related to (((4))), there is provided a toner for developing electrostatic images which has low-temperature fixability and can form images with reduced gloss unevenness, compared to when the glass transition temperature Tg of the internally added crosslinked resin particles is less than 0°C or more than 40°C. According to the invention of (((5))), the ratio of the content of the crystalline resin to the amount of externally added inorganic particles (amount of externally added inorganic particles / content of the crystalline resin) is 1.0×10 -2 Less than or 10.0 x 10 -2 The present invention provides a toner for developing electrostatic images that has low-temperature fixability and can form images with reduced gloss unevenness, as compared with a case where the toner exceeds 1000 kJ / cm 2 . According to the invention of (((6))), the ratio of the content of the crystalline resin to the amount of externally added inorganic particles (amount of externally added inorganic particles / content of the crystalline resin) is 2.0×10 -2 Less than or 8.0 x 10 -2The present invention provides a toner for developing electrostatic images that has low-temperature fixability and can form images with reduced gloss unevenness, as compared with a case where the toner exceeds 1000 kJ / cm 2 .

[0197] According to the invention related to (((7))), there is provided a toner for developing electrostatic images, which comprises toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, and the external additive is inorganic particles having a specific gravity of less than 1.3 or more than 2.0, or when the toner particles are cooled from 110°C to 30°C, the ratio of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), is less than 0.90 or more than 1.40, or the loss tangent tanδ(80) at a temperature of 80°C is less than 1.20 or more than 1.70, even when the toner contains a crystalline polyester resin, the toner has low temperature fixability and suppresses gloss unevenness, compared to when the external additive is inorganic particles having a specific gravity of less than 1.3 or more than 2.0, or when the toner particles are cooled from 110°C to 30°C, the ratio of the loss tangent tanδ(80) at a temperature of 80°C to the loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), is less than 0.90 or more than 1.40, or when the loss tangent tanδ(80) at a temperature of 80°C is less than 1.20 or more than 1.70. A toner for developing electrostatic images is provided that can form controlled images. According to the invention related to (((8))) ))), there is provided a toner for developing electrostatic images which has low-temperature fixing ability and can form images with reduced gloss unevenness, compared to when the content of the crystalline resin is less than 10% by mass or more than 30% by mass.

[0198] According to the invention (((9))), the ratio AV1 / M1 of the amount of metal ions M1 to the acid value AV1 of the binder resin is 1.0×10 3 Less than or 4.0 x 10 3 The present invention provides a toner for developing electrostatic images that has low-temperature fixability and can form images with reduced gloss unevenness, as compared with a case where the toner exceeds 1000 kJ / cm 2 . According to the invention (((10))), the ratio AV1 / M1 of the amount of metal ions M1 to the acid value AV1 of the binder resin is 2.0×10 3 Less than or 3.5 x 10 3 As compared with the above, a toner for developing electrostatic images is provided which has low-temperature fixability and can form images with reduced gloss unevenness.

[0199] According to the inventions of (((11))), (((12))), (((13))), (((14))) or (((15))), there is provided a toner for developing electrostatic images, which comprises toner particles containing an amorphous resin and a crystalline resin as binder resins, and an external additive, and in the case where the inorganic particles as the external additive are inorganic particles having a specific gravity of less than 1.3 or more than 2.0, or in the case where the toner particles have a loss tangent tan The present invention provides an electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, or image forming method that can form images with reduced gloss unevenness while maintaining low-temperature fixability, compared to when an electrostatic image developing toner is used, in which the ratio of δ(80) / tan δ(60) of δ(80) to the loss tangent tan δ(60) at a temperature of 60°C is less than 0.90 or exceeds 1.40, or the loss tangent tan δ(80) at a temperature of 80°C is less than 1.20 or exceeds 1.70. [Explanation of symbols]

[0200] 1Y, 1M, 1C, 1K Photoconductor (an example of an image carrier) 2Y, 2M, 2C, 2K Charging roll (example of charging device) 3. Exposure device (an example of an electrostatic image forming device) 3Y, 3M, 3C, 3K laser beam 4Y, 4M, 4C, 4K developing device (example of developing device) 5Y, 5M, 5C, 5K Primary transfer roll (an example of a primary transfer device) 6Y, 6M, 6C, 6K Photoconductor cleaning device (example of cleaning device) 8Y, 8M, 8C, 8K toner cartridges 10Y, 10M, 10C, 10K image forming units 20 Intermediate transfer belt (an example of an intermediate transfer body) 22 Drive Roll 24 Support Roll 26 Secondary transfer roll (an example of a secondary transfer device) 28 Fixing device (example of fixing device) 30 Intermediate transfer body cleaning device 107 Photosensitive body (an example of an image carrier) 108 Charging roll (an example of a charging device) 109 Exposure device (an example of an electrostatic image forming device) 111 Developing device (an example of a developing device) 112 Transcription device (an example of a transcription device) 113 Photosensitive drum cleaning device (an example of a cleaning device) 115 Fixing device (an example of a fixing device) 116 Mounting Rail 118 Exposure opening 117 Cabinet 200 Process Cartridge 300 Recording paper (an example of a recording medium) P Recording paper (an example of a recording medium)

Claims

1. The toner includes toner particles containing an amorphous resin and a crystalline resin as a binder resin, and an external additive, the external additive contains inorganic particles having a specific gravity of 1.3 or more and 2.0 or less, The toner for developing electrostatic images has, in a dynamic viscoelasticity measurement when the temperature of the toner particles is lowered from 110°C to 30°C, a ratio of loss tangent tanδ(80) at a temperature of 80°C to loss tangent tanδ(60) at a temperature of 60°C, tanδ(80) / tanδ(60), of 0.90 or more and 1.40 or less, and the loss tangent tanδ(80) at a temperature of 80°C is 1.20 or more and 1.70 or less.

2. 2. The toner for developing electrostatic images according to claim 1, wherein the inorganic particles have a volume average particle size of 30 nm or more and 80 nm or less.

3. 2. The toner for developing electrostatic images according to claim 1, wherein the toner particles contain internally added crosslinked resin particles.

4. 4. The toner for developing electrostatic images according to claim 3, wherein the glass transition temperature Tg of the internally added crosslinked resin particles is 0° C. or higher and 40° C. or lower.

5. The ratio of the content of the crystalline resin to the externally added amount of the inorganic particles (externally added amount of inorganic particles / content of crystalline resin) is 1.0 × 10 -２ Above 10.0 x 10 -２ 2. The toner for developing electrostatic images according to claim 1, wherein the toner is:

6. The ratio of the content of the crystalline resin to the externally added amount of the inorganic particles (externally added amount of inorganic particles / content of crystalline resin) is 2.0 × 10 -２ Above 8.0 x 10 -２ 6. The toner for developing electrostatic images according to claim 5, wherein the toner is:

7. 2. The toner for developing electrostatic images according to claim 1, wherein the crystalline resin is a crystalline polyester resin.

8. 2. The toner for developing electrostatic images according to claim 1, wherein the content of the crystalline resin relative to the binder resin is 10% by mass or more and 30% by mass or less.

9. the toner particles contain one or more metal ions selected from the group consisting of Al, Mg, and Ca; The ratio AV1 / M1 of the amount M1 of the metal ions to the acid value AV1 of the binder resin is 1.0×10 ３ Above 4.0 x 10 ３ 2. The toner for developing electrostatic images according to claim 1, wherein the toner is:

10. The ratio AV1 / M1 of the amount M1 of the metal ions to the acid value AV1 of the binder resin is 2.0×10 ３ 3.5 x 10 ３ 10. The toner for developing electrostatic images according to claim 9, wherein the toner is:

11. An electrostatic image developer comprising the toner for developing electrostatic images according to any one of claims 1 to 10.

12. A toner for developing electrostatic images according to any one of claims 1 to 10 is contained therein, A toner cartridge that is detachably attached to an image forming device.

13. a developing device containing the electrostatic image developer according to claim 11 and developing an electrostatic image formed on a surface of an image carrier into a toner image by using the electrostatic image developer; A process cartridge is detachably mounted in an image forming apparatus.

14. an image carrier; a charging device that charges the surface of the image carrier; an electrostatic image forming device for forming an electrostatic image on the charged surface of the image carrier; a developing device containing the electrostatic image developer according to claim 11 and developing the electrostatic image formed on the surface of the image carrier into a toner image by the electrostatic image developer; a transfer device that transfers the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing device for fixing the toner image transferred onto the surface of the recording medium; An image forming apparatus comprising:

15. a charging step of charging the surface of the image carrier; an electrostatic image forming step of forming an electrostatic image on the charged surface of the image carrier; a developing step of developing the electrostatic image formed on the surface of the image carrier into a toner image by using the electrostatic image developer according to claim 11; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium; a fixing step of fixing the toner image transferred onto the surface of the recording medium; An image forming method comprising the steps of:

Images