Electrostatic charge image developing toner, electrostatic charge image developer, toner cartridge, process cartridge, image forming device, and image forming method

Abstract

To provide an electrostatic charge image developing toner that offers good color developability.SOLUTION: An electrostatic charge image developing toner provided herein comprises toner particles containing a resin and a colorant. When a net intensity of Br element measured by X-ray fluorescence analysis of the toner particles is defined as IBr, and a net intensity of S element measured by X-ray fluorescence analysis is defined as IS, IBr is in a range of 1 to 30 kcps, inclusive, and IS / IBr is in a range of 0.005 to 1.2, inclusive.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 discloses a method for producing an electrophotographic toner comprising toner particles containing a binder resin and a colorant obtained by a chelate reaction between a dye compound having a specific structure and a copper complex compound having a specific structure, the method comprising the steps of adding an aggregating agent made of a compound that does not contain metal atoms to an aqueous medium in which fine particles made of the binder resin, fine particles made of the dye compound, and fine particles made of the copper complex compound are dispersed, and aggregating the fine particles made of the binder resin, the fine particles made of the dye compound, and the fine particles made of the copper complex compound.

[0003] Patent Document 2 discloses a magenta toner for developing electrostatic images, which contains an amorphous resin and a crystalline polyester resin as binder resins, and which contains, as colorants, a quinacridone pigment having a specific structure, a metal element-containing monoazo pigment having a specific structure, and a naphthol AS pigment having a specific structure, and the total content of the quinacridone pigment and the metal element-containing monoazo pigment is 50 to 90 mass % of the total colorants. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-169697 [Patent Document 2] Japanese Patent Application Publication No. 2018-173558 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a toner for developing electrostatic images which has better color development properties than when IBr is less than 1 kcps or more than 30 kcps, or when IS / IBr is less than 0.005 or more than 1.2. [Means for solving the problem]

[0006] Means for solving the above problems include the following aspects. <1> toner particles containing a resin and a colorant; In the toner particles, when the net intensity of the Br element measured by fluorescent X-ray analysis is IBr and the net intensity of the S element measured by fluorescent X-ray analysis is IS, IBr is 1 kcps or more and 30 kcps or less, and IS / IBr is 0.005 or more and 1.2 or less, Toner for developing electrostatic images. <2> When the net intensity of O element in the toner particles measured by fluorescent X-ray analysis is defined as IO, IBr / IO is 4.76 or more and 333 or less. <1> 2. The toner for developing electrostatic images according to claim 1. <3> IBr is 10 kcps or more and 25 kcps or less, <1> or <2> 2. The toner for developing electrostatic images according to claim 1. <4> IS / IBr is 0.03 or more and 0.06 or less, <3> 2. The toner for developing electrostatic images according to claim 1. <5> IBr / IO is between 83.3 and 143, <2> ~ <4> 10. The toner for developing electrostatic images according to claim 9, wherein the toner is a toner for developing electrostatic images. <6> The resin includes a polyester resin. <1> ~ <5> 10. The toner for developing electrostatic images according to claim 9, wherein the toner is a toner for developing electrostatic images. <7> the toner particles contain a release agent containing an ester wax; <1> ~ <6> 10. The toner for developing electrostatic images according to claim 9, wherein the toner is a toner for developing electrostatic images. <8> <1> ~ <7> 10. An electrostatic image developer comprising the toner for developing electrostatic images according to any one of claims 1 to 9. <9> <1> ~ <7> 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. <10> <8> a developing device that contains the electrostatic image developer according to claim 1 and develops 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. <11> 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; <8> 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: <12> 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; <8> 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), a toner for developing electrostatic images is provided which has better color development properties than when IBr is less than 1 kcps or more than 30 kcps, or when IS / IBr is less than 0.005 or more than 1.2. <2> According to the invention relating to (1), a toner for developing electrostatic images having good color development properties is provided, compared to when IBr / IO is less than 4.76 or more than 333. <3> According to the invention relating to (1), a toner for developing electrostatic images is provided which has better color development properties than when the IBr is less than 10 kcps or more than 25 kcps. <4> According to the invention relating to (1), a toner for developing electrostatic images is provided which has better color development properties than when IS / IBr is less than 0.03 or exceeds 0.06. <5> According to the invention relating to (1), a toner for developing electrostatic images having good color development properties is provided, compared to when IBr / IO is less than 83.3 or more than 143. <6> According to the invention, a toner for developing electrostatic images is provided which has better color development properties than when the resin is made of a styrene acrylic resin. <7> According to the invention, there is provided a toner for developing electrostatic images which has better color development properties than a toner containing a release agent made of paraffin wax. <8> , <9> , <10> , <11> , or <12> According to the invention, there is provided an electrostatic image developer, a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method that can obtain images with higher saturation than when a toner for developing electrostatic images having an IBr of less than 1 kcps or more than 30 kcps, or an IS / IBr of less than 0.005 or more than 1.2 is used. [Brief explanation of the drawings]

[0008] [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

[0009]

[0023] The following describes embodiments of the present disclosure. These descriptions and examples are intended to illustrate the embodiments and are not intended to limit the scope of the embodiments.

[0010] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0011] In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples.

[0012] In the present disclosure, 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.

[0013] When embodiments of the present disclosure are described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to these.

[0014] In the present disclosure, each component may contain multiple corresponding substances. When referring to the amount of each component in a composition in the present disclosure, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified.

[0015] In the present disclosure, the composition may contain multiple types of particles corresponding to each component. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0016] In the present disclosure, "(meth)acrylic" means at least one of acrylic and methacrylic, and "(meth)acrylate" means at least one of acrylate and methacrylate.

[0017] [Electrostatic image developing toner] The toner for developing electrostatic images according to the present embodiment (hereinafter also simply referred to as "toner") includes toner particles containing a resin and a colorant, and when the net intensity of Br element measured by fluorescent X-ray analysis in the toner particles is IBr and the net intensity of S element measured by fluorescent X-ray analysis is IS, IBr is 1 kcps or more and 30 kcps or less, and IS / IBr is 0.005 or more and 1.2 or less. In this embodiment, when IBr and IS / IBr are in the above ranges, the color development is good. The reason for this is not clear, but is presumed to be as follows.

[0018] In a toner containing toner particles containing a resin and a colorant, uneven distribution of the colorant within the toner particles tends to reduce color development, whereas good dispersion of the colorant tends to improve color development. By using a toner with good color development, it becomes easier to obtain images with high saturation. In addition, in toner particles containing an appropriate amount of bromide ions, it is believed that the repulsive force of the bromide ions allows each component, such as the colorant, to be dispersed well during the toner particle manufacturing process. On the other hand, if the amount of bromide ions is large and the repulsive force of the bromide ions is too strong, the colorant may be unevenly distributed and may be prone to aggregation. Furthermore, in toner particles containing an appropriate amount of sulfide ions, the bromide ions are dispersed well during the toner particle manufacturing process due to the repulsive force between the sulfide ions and the bromide ions, which is thought to further improve the colorant dispersion effect of the bromide ions. On the other hand, if the amount of sulfide ions present is too large relative to the amount of bromide ions, the repulsive force between the sulfide ions and the bromide ions becomes too strong, making it difficult for the bromide ions to disperse, and this may reduce the colorant dispersion effect of the bromide ions.

[0019] In contrast, in this embodiment, IBr and IS / IBr are each within the above ranges. That is, in this embodiment, a moderate amount of bromide ions are present in the toner particles, and the ratio of the amount of sulfide ions present to the amount of bromide ions present is also moderate. Therefore, in this embodiment, the colorant dispersion effect of bromide ions is more easily achieved than when IBr is smaller than the above range or when IS / IBr is smaller than the above range. In addition, aggregation of the colorant due to the repulsive force of bromide ions being too strong is suppressed compared to when IBr is larger than the above range, and the repulsive force between sulfide ions and bromide ions is not too strong compared to when IS / IBr is larger than the above range, making it easier to achieve the colorant dispersion effect of bromide ions. For the above reasons, it is presumed that the toner of this embodiment has good color development properties.

[0020] <Net intensity of each element> The method for measuring the net intensity of each element in the toner particles by fluorescent X-ray analysis is as follows. 140 mg of toner particles are compressed using a compression molding machine under a load of 10 tonnes for 60 seconds to produce a disk with a diameter of 10 mm. This disk is used as a sample for a total elemental analysis under the following measurement conditions using a scanning X-ray fluorescence analyzer (Rigaku ZSX Primus II) to determine the net intensity (unit: kilocounts per second, kcps) of each element being measured. When performing the above measurement on an externally added toner in which an external additive is attached to the toner particles, the measurement may be performed using toner particles from which the external additive has been removed. Alternatively, the measurement may be performed using the externally added toner as is instead of the toner particles, and the net intensity of each element in the toner particles may be calculated by correcting for the influence of the external additive.

[0021] -Measurement conditions- Tube voltage: 40kV Tube current: 70mA Anticathode: Rhodium Measurement time: 15 minutes Analysis diameter: diameter 10mmφ

[0022] As described above, the IBr is from 1 kcps to 30 kcps, and from the viewpoint of obtaining good color development, it is preferably from 10 kcps to 25 kcps, and more preferably from 13 kcps to 23 kcps. It is presumed that when IBr is equal to or greater than the lower limit, the repulsive force of bromide ions improves the dispersibility of the colorant, resulting in good color development of the toner. It is also presumed that when IBr is equal to or less than the upper limit, aggregation of the colorant caused by excessively strong repulsive force of bromide ions is suppressed, resulting in good color development of the toner.

[0023] Since IBr is a net intensity measured by X-ray fluorescence analysis and represents the amount of Br contained in the entire toner particle (mainly the interior), a method for controlling IBr within the above range includes adding a compound containing a bromine atom (hereinafter also referred to as a "bromine-containing compound") in the toner particle production process and adjusting the amount added. The bromine-containing compound may be, for example, an aggregating agent used when producing toner particles by the aggregation-coalescence method described below. Examples of bromine-containing compounds include quaternary ammonium salts such as ammonium bromide, decyltrimethylammonium bromide, tetramethylammonium bromide, tetradecylammonium bromide, and alkylbenzyldimethylammonium bromide; iron bromide; zinc bromide; alkali metal bromides such as lithium bromide, sodium bromide, potassium bromide, rubidium bromide, cesium bromide, and francium bromide; and alkaline earth metal bromides such as beryllium bromide, magnesium bromide, strontium bromide, barium bromide, and radium bromide. From the viewpoint of favorable dispersion of each component, such as a colorant, the bromine-containing compound is preferably a quaternary ammonium salt, and more preferably a tetraalkylammonium bromide.

[0024] The IS may be, for example, in the range of 0.075 kcps or more and 18 kcps or less, and from the viewpoint of obtaining good color development, it is preferably 0.3 kcps or more and 10 kcps or less, and more preferably 0.5 kcps or more and 3 kcps or less. As described above, IS / IBr is 0.005 or more and 1.2 or less, and from the viewpoint of obtaining good color development, it is preferably 0.015 or more and 0.08 or less, and more preferably 0.03 or more and 0.06 or less. It is presumed that when IS / IBr is equal to or greater than the lower limit, the repulsive force between sulfide ions and bromide ions disperses bromide ions well, further improving the colorant dispersion effect of bromide ions, resulting in good color development of the toner. It is also presumed that when IS / IBr is equal to or less than the upper limit, the repulsive force between sulfide ions and bromide ions is too strong, preventing bromide ions from becoming difficult to disperse, resulting in good color development of the toner.

[0025] The IS can be controlled by adding a compound containing a sulfur atom (hereinafter also referred to as a "sulfur-containing compound") in the toner particle production process and adjusting the amount of the compound added. The sulfur-containing compound may be, for example, a surfactant used when producing toner particles by the aggregation-coalescence method described below. Examples of sulfur-containing compounds include sodium alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate and sodium polyoxyethylene arylphenyl ether sulfonate; sodium polyoxyethylene alkyl ether sulfonate; etc. From the viewpoint of dispersibility of the colorant, the sulfur-containing compound is preferably sodium alkylbenzenesulfonate.

[0026] When the net intensity of the O element is I0, I0 is, for example, in the range of 0.01 kcps or more and 4.0 kcps or less, and from the viewpoint of obtaining good color development, I0 is preferably 0.04 kcps or more and 3.0 kcps or less, and more preferably 0.1 kcps or more and 1.0 kcps or less. From the viewpoint of obtaining good color development, IBr / IO is preferably 4.76 or more and 333 or less, more preferably 83.3 or more and 143 or less, and even more preferably 90 or more and 120 or less. When the IBr / IO ratio is within the above range, the toner exhibits good color development. While the reason for this is unclear, it is speculated as follows. For example, if the resin contained in the toner particles has an ester bond, the O element present in the toner particles may originate primarily from the oxygen atoms of the ester bond contained in the resin. Furthermore, if the toner particles contain a release agent with an ester bond, the oxygen atoms of the ester bond contained in the release agent may also be the source of the O element. Hereinafter, the component from which the O element originates is also referred to as the "O element-derived component." When the IBr / IO ratio is equal to or greater than the above lower limit, sufficient bromide ions are present relative to the oxygen atoms. The bromide ions repel the negative polarity of the oxygen atoms contained in the O element-derived component, making the O element-derived component more easily dispersible. Furthermore, it is speculated that the easier dispersion of the O element-derived component (i.e., the resin, etc.) also improves the dispersibility of the colorant, resulting in good toner color development. Furthermore, when IBr / IO is equal to or less than the upper limit, uneven distribution of O element-derived components caused by the excess presence of bromide ions relative to oxygen atoms is suppressed, and a decrease in dispersibility of the colorant caused by uneven distribution of O element-derived components (i.e., resins, etc.) is also suppressed, which is presumably why the color development of the toner is improved.

[0027] Methods for controlling IO include using a resin containing oxygen atoms and adjusting the content of the resin; adding a release agent containing oxygen atoms and adjusting the amount added; adding an oxidizing agent such as ozone to introduce oxygen atoms into the resin and adjusting the amount added (i.e., adjusting the amount of oxygen atoms introduced); and combinations of these. Examples of resins containing oxygen atoms include polyester resins, acrylic resins, styrene-acrylic resins, epoxy resins, polyurethane resins, polyamide resins, cellulose resins, and polyether resins. The resin containing oxygen atoms may be a resin containing a structure with a high oxygen ratio, such as polyvinyl alcohol. Among these, the resin containing oxygen atoms is preferably a resin having an ester bond, more preferably a resin having an ester bond in the main chain, and even more preferably a polyester resin, from the viewpoint of obtaining good color development properties by controlling the IBr / IO ratio within the above range. The resin preferably contains at least one selected from the group consisting of polyester resins and styrene-acrylic resins, and more preferably contains at least a polyester resin. The resin may contain both a polyester resin and a styrene-acrylic resin to facilitate control of the IBr / IO ratio. Examples of release agents containing oxygen atoms include ester waxes, and among ester waxes, pentaerythritol alkyl esters are preferred from the viewpoint of obtaining good color development. The release agent may contain two or more types of release agents to facilitate control of IBr / IO. Examples of combinations of two or more release agents include a combination of an ester wax and a hydrocarbon wax. The oxidizing agent is not particularly limited as long as it is a compound that introduces oxygen atoms into resins, etc., and examples thereof include ozone.

[0028] The toner according to this embodiment will be described in detail below.

[0029] The toner according to the present embodiment includes toner particles and may include an external additive.

[0030] (toner particles) The toner particles contain, for example, a resin, and may also contain a colorant, a release agent, and other additives.

[0031] -resin- Examples of the resin 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 (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 the resin 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 resins may be used alone or in combination of two or more.

[0032] The resin is preferably a polyester resin. Examples of polyester resins include known amorphous polyester resins. The polyester resin may be used in combination with a crystalline polyester resin. However, the content of the crystalline polyester resin is preferably in the range of 2% by mass to 40% by mass (preferably 2% by mass to 20% by mass) relative to the total resin.

[0033] 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.

[0034] Amorphous polyester resin 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] Crystalline polyester resin 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.

[0041] 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.

[0042] 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.

[0043] Here, the polyhydric alcohol has an aliphatic diol content of 80 mol % or more, preferably 90 mol % or more.

[0044] 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 85°C or lower. The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC) 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."

[0045] The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

[0046] The crystalline polyester resin can be obtained by a known manufacturing method, for example, in the same manner as the amorphous polyester.

[0047] When the resin contains a polyester resin, the content of the polyester resin relative to the total resin is, for example, 20% by mass or more and 100% by mass or less, and preferably 40% by mass or more and 100% by mass or less.

[0048] Suitable resins also include vinyl-based resins. The vinyl resin will now be described. Examples of vinyl resins include 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 vinyl resins made of copolymers of two or more of these monomers. These vinyl resins may be used alone or in combination of two or more.

[0049] As the vinyl resin, a styrene acrylic resin is preferred from the viewpoint of excellent environmental stability of toner charging. Styrene-acrylic resin is a copolymer obtained by copolymerizing at least a styrene-based monomer (a monomer having a styrene skeleton) and a (meth)acrylic-based monomer (a monomer having a (meth)acryloyl group, preferably a monomer having a (meth)acryloyloxy group). Styrene-acrylic resin includes, for example, a copolymer of a styrene monomer and the above-mentioned (meth)acrylic acid ester monomer. The acrylic resin portion in the styrene-acrylic resin is either an acrylic monomer or a methacrylic monomer, or a partial structure obtained by polymerizing them. Furthermore, the term "(meth)acrylic" includes both "acrylic" and "methacrylic."

[0050] Specific examples of styrene-based monomers include styrene, alkyl-substituted styrenes (e.g., α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, etc.), halogen-substituted styrenes (e.g., 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, etc.), vinylnaphthalene, etc. The styrene-based monomers may be used alone or in combination of two or more. Of these, styrene is preferred as the styrene-based monomer in terms of ease of reaction, ease of reaction control, and availability.

[0051] Specific examples of (meth)acrylic monomers include (meth)acrylic acid and (meth)acrylic acid esters. Examples of (meth)acrylic acid esters include (meth)acrylic acid alkyl esters (e.g., methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl 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, n-octadecyl (meth)acrylate, isopropyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isopentyl (meth)acrylate, amyl (meth)acrylate, and (meth) Examples of the (meth)acrylic acid monomer include neopentyl acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, etc.), aryl (meth)acrylate esters (e.g., phenyl (meth)acrylate, biphenyl (meth)acrylate, diphenylethyl (meth)acrylate, t-butylphenyl (meth)acrylate, terphenyl (meth)acrylate, etc.), dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, methoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, β-carboxyethyl (meth)acrylate, and (meth)acrylamide. The (meth)acrylic acid monomers may be used alone or in combination of two or more. Among these (meth)acrylic esters among the (meth)acrylic monomers, from the viewpoint of improving the fixability of the toner, (meth)acrylic esters having an alkyl group having 2 to 14 carbon atoms (preferably 2 to 10 carbon atoms, more preferably 3 to 8 carbon atoms) are preferred. Among these, n-butyl (meth)acrylate is preferred, and n-butyl acrylate is particularly preferred.

[0052] The copolymerization ratio of the styrene-based monomer to the (meth)acrylic monomer (based on mass, styrene-based monomer / (meth)acrylic monomer) is not particularly limited, but is preferably 98 / 2 to 60 / 40.

[0053] The glass transition temperature (Tg) of the styrene acrylic resin is preferably 40° C. or more and 75° C. or less, and more preferably 50° C. or more and 65° C. or less, from the viewpoint of improving the fixability of the toner.

[0054] The glass transition temperature of the resin is determined from a DSC curve obtained by differential scanning calorimetry (DSC). More specifically, the glass transition temperature of the resin is determined by the "extrapolated glass transition onset temperature" described in JIS K 7121:1987 "Method for measuring the transition temperature of plastics."

[0055] From the viewpoint of storage stability of the toner, the weight average molecular weight of the styrene acrylic resin is preferably from 5,000 to 200,000, more preferably from 10,000 to 100,000, and particularly preferably from 20,000 to 80,000.

[0056] The method for producing the styrene-acrylic resin is not particularly limited, and various polymerization methods (e.g., solution polymerization, precipitation polymerization, suspension polymerization, bulk polymerization, emulsion polymerization, etc.) are applied. In addition, the polymerization reaction is carried out by a known operation (e.g., batchwise, semi-continuous, continuous, etc.).

[0057] The toner particles preferably contain at least one selected from the group consisting of polyester resin and vinyl resin, and may contain both a polyester resin and a vinyl resin, or only one of them. When the toner particles contain both a polyester resin and a vinyl resin, the toner particles may contain both a polyester resin and a vinyl resin as binder resins, or may contain one of a polyester resin and a vinyl resin as binder resin and the other as resin particles. When the toner particles contain one of a polyester resin and a vinyl resin as resin particles, the resin particles may have a crosslinked structure. When the toner particles contain both a polyester resin and a vinyl resin, the mass ratio C of the polyester resin to the vinyl resin is, for example, 0.7 or more and 10 or less, or may be 1 or more and 6 or less, or 1 or more and 5 or less.

[0058] An example of a resin containing both a polyester resin and a vinyl resin is a resin in which a styrene-acrylic resin and a polyester resin coexist. Here, the coexistence of styrene-acrylic resin and polyester resin can be achieved not only by mixing the respective resins, but also as a chemically bonded hybrid resin having a styrene-acrylic resin segment and a polyester resin segment (so-called styrene-acrylic modified polyester resin). Specifically, a hybrid resin can be obtained by polymerizing a polyester monomer having an unsaturated structure such as fumaric acid or succinic acid or a resin containing such a monomer structure as a prepolymer with a vinyl monomer such as styrene or acrylic. When a hybrid resin (a so-called styrene-acrylic modified polyester resin) is used, the mass ratio C of the polyester resin to the vinyl resin is measured and calculated as the mass ratio of the polyester segment to the vinyl resin segment (e.g., styrene-acrylic resin segment) of the hybrid resin. When a hybrid resin, a vinyl resin (e.g., styrene-acrylic resin), and a polyester resin are used in combination, the mass ratio C is measured and calculated as the mass ratio of the sum of the polyester resin segment and the polyester resin of the hybrid resin to the sum of the vinyl resin segment and the vinyl resin of the hybrid resin.

[0059] The resin content is, for example, preferably 40% by mass to 95% by mass, more preferably 50% by mass to 93% by mass, and even more preferably 60% by mass to 93% by mass, based on the total mass of the toner particles.

[0060] -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.

[0061] 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.

[0062] 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.

[0063] -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. The release agent is preferably an ester wax. The ester wax is a wax having an ester bond. The ester wax may be any of monoester, diester, triester, and tetraester, and known natural or synthetic ester waxes can be used. Examples of the ester wax include ester compounds of higher fatty acids (such as fatty acids having 10 or more carbon atoms) and monohydric or polyhydric aliphatic alcohols (such as fatty alcohols having 8 or more carbon atoms). Examples of ester waxes include ester compounds of higher fatty acids (caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, oleic acid, montanic acid, etc.) with alcohols (monohydric alcohols such as methanol, ethanol, propanol, isopropanol, butanol, capryl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, and oleyl alcohol; and polyhydric alcohols such as glycerin, ethylene glycol, propylene glycol, sorbitol, and pentaerythritol). Specific examples include carnauba wax, rice wax, candelilla wax, jojoba oil, Japan wax, beeswax, privet wax, lanolin, and montanic acid ester wax.

[0064] 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 105°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."

[0065] The content of the release agent is, for example, preferably 1% by mass or more and 20% 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.

[0066] -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.

[0067] The toner particles may contain a bromine-containing compound as the source of the Br element. Specific examples of the bromine-containing compound are as described above. The content of the bromine-containing compound relative to the total toner particles may be, for example, in the range of 0.04% by mass to 0.4% by mass, or may be in the range of 0.05% by mass to 0.3% by mass, or may be in the range of 0.06% by mass to 0.25% by mass. The toner particles may contain a sulfur-containing compound as the source of the S element. Specific examples of the sulfur-containing compound are as described above. The content of the sulfur-containing compound relative to the total amount of the toner particles may be, for example, in the range of 0.001% by mass to 0.02% by mass, or may be in the range of 0.002% by mass to 0.015% by mass, or may be in the range of 0.003% by mass to 0.012% by mass.

[0068] -Characteristics of toner particles, etc.- 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 be composed of, for example, a core containing a binder resin and, if necessary, other additives such as a colorant and a release agent, and a coating layer containing the binder resin.

[0069] 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.

[0070] 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:

[0071] 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.

[0072] 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 a still image of the particles is captured by instantaneously activating a strobe light, and the particle image is analyzed using a flow-type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation).The number of samples to be sampled when calculating 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.

[0073] (external additives) Examples of external additives include inorganic particles, such as SiO2, TiO2, Al2O3, SrTiO3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, and K2O·(TiO2). n , Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, MgSO4, etc.

[0074] The surfaces of inorganic particles 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, and 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 or more and 10 parts by mass or less per 100 parts by mass of the inorganic particles.

[0075] 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).

[0076] The amount of the external additive added is, for example, 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.

[0077] (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.

[0078] 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.

[0079] Specifically, for example, when toner particles are produced by the aggregation and coalescence method, for example, a step of mixing a first resin particle dispersion liquid in which first resin particles serving as a binder resin are dispersed, a colorant dispersion liquid in which a colorant is dispersed, and a release agent particle dispersion liquid in which particles of a release agent (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 resin particles serving 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, and aggregating the second resin particles onto the surfaces of the first aggregated particles to form 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.

[0080] As described above, one method for controlling IBr within the above range is to add a bromine-containing compound during the toner particle production process and adjust the amount added. When toner particles are produced by the aggregation-coalescence method, it is preferable to add the bromine-containing compound in at least one of the first aggregate particle formation step and the second aggregate particle formation step, and it is more preferable to add the bromine-containing compound in the first aggregate particle formation step. The amount of the bromine-containing compound added is, for example, from 0.5 to 3.0 parts by mass, per 100 parts by mass of the total components constituting the toner particles, and may be in the range of from 1 to 2.5 parts by mass, or may be in the range of from 1.5 to 2.0 parts by mass.

[0081] As described above, one method for controlling IS is to add a sulfur-containing compound during the toner particle production process and adjust the amount of the compound added. When toner particles are produced by the aggregation-coalescence method, it is preferable to add the sulfur-containing compound during at least one of the first aggregate particle formation step and the second aggregate particle formation step, and it is more preferable to add the sulfur-containing compound during the first aggregate particle formation step. The amount of the sulfur-containing compound added is, for example, from 0.003% to 0.03% by mass, based on the total amount of components constituting the toner particles, and may be in the range of from 0.005% to 0.02% by mass, or may be in the range of from 0.008% to 0.012% by mass.

[0082] As mentioned above, one method for controlling the IO is to add an oxidizing agent such as ozone and adjust the amount added. When producing toner particles by the aggregation-coalescence method, it is preferable to add the oxidizing agent in at least one of the first aggregate particle formation step and the second aggregate particle formation step, and it is more preferable to add the oxidizing agent in the first aggregate particle formation step. When using ozone as the oxidizing agent, it is preferable to add it as ozone water, and more preferably as ozone water with a concentration of 2 ppm by mass or more and 8 ppm by mass or less. The amount of ozone water added is, for example, 0.005 parts by mass or more and 18 parts by mass or less, per 100 parts by mass of the total components constituting the toner particles, and may be in the range of 0.008 parts by mass or more and 15 parts by mass or less, or 0.01 parts by mass or more and 12 parts by mass or less.

[0083] Each step will be described in detail below.

[0084] -Each dispersion preparation process- First, the various dispersions to be used in the aggregation-coalescence method are prepared: a first resin particle dispersion in which first resin particles that will become the binder resin are dispersed, a colorant dispersion in which a colorant is dispersed, a second resin particle dispersion in which second resin particles that will become the binder resin are dispersed, and a release agent particle dispersion in which release agent particles are dispersed. In each dispersion preparation step, the first resin particles and the second resin particles will be referred to as "resin particles."

[0085] Here, the resin particle dispersion liquid is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] Note that, for example, a colorant dispersion and a release agent particle dispersion are also prepared in the same manner as the resin particle dispersion. 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 and the release agent particles dispersed in the release agent particle dispersion.

[0092] -First agglomerated particle formation process- Next, the first resin particle dispersion liquid, the colorant dispersion liquid, and the release agent particle dispersion liquid are mixed together. Then, in this mixed dispersion, the first resin particles, the colorant, and the release agent particles are hetero-aggregated to form first aggregated particles containing the first resin particles, the colorant, and the release agent particles.

[0093] Specifically, for example, an aggregating agent is added to a dispersion liquid obtained by mixing a first resin particle dispersion liquid, a colorant dispersion liquid, and a release agent particle dispersion liquid, and the pH of the mixed dispersion liquid is adjusted to be acidic (for example, a pH of 2 or more and 5 or less), and a dispersion stabilizer is added as necessary.After that, 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 liquid 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.

[0094] 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.

[0095] 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, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass, relative to 100 parts by mass of the first resin particles.

[0096] -Second agglomerated particle formation process- Next, after obtaining the first aggregated particle dispersion liquid in which the first aggregated particles are dispersed, the second resin particle dispersion liquid in which the second resin particles are dispersed is added to the first aggregated particle dispersion liquid. The second resin particles may be of the same type as the first resin particles, or may be of a different type.

[0097] Then, in the dispersion of the first aggregated particles and the second resin particles, the second 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 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 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 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 resin particles adhere to the surfaces of the first aggregated particles.

[0098] -Fusion / coalescence 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 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] <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.

[0103] 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.

[0104] Examples of magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] <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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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).

[0117] 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 -6The 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.

[0118] 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 (developed) as a toner image by the developing device 4Y.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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 made up 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] <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.

[0127] 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.

[0128] 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.

[0129] 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).

[0130] 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.

[0131] 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]

[0132] Hereinafter, embodiments of the present invention will be described in detail with reference to examples, but the embodiments of the present invention are not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are based on mass.

[0133] <Preparation of various dispersions> (Synthesis of amorphous polyester resin (A)) Terephthalic acid: 68 parts Fumaric acid: 32 parts Ethylene glycol: 42 parts 1,5-pentanediol: 47 parts The above materials were placed in a flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and distillation column, and the temperature was raised to 220°C over 1 hour under a nitrogen gas stream. One part of titanium tetraethoxide was then added for every 100 parts of the above materials. The temperature was raised to 240°C over 0.5 hours while distilling off the resulting water. The dehydration condensation reaction was continued at 240°C for 1 hour, after which the reaction mixture was cooled. Thus, an amorphous polyester resin (A) with a weight-average molecular weight of 97,000 and a glass transition temperature of 60°C was obtained.

[0134] (Preparation of amorphous polyester resin particle dispersion (A1)) A vessel equipped with a temperature control device and a nitrogen purge device was charged with 40 parts of ethyl acetate and 25 parts of 2-butanol to prepare a mixed solvent. Then, 100 parts of amorphous polyester resin (A) was gradually added and dissolved. A 10% aqueous ammonia solution (equivalent to three times the molar amount of the resin's acid value) was added and stirred for 30 minutes. The atmosphere inside the vessel was then purged with dry nitrogen, the temperature was maintained at 40°C, and 400 parts of ion-exchanged water was added dropwise to the stirred mixture to emulsify it. After the addition, the emulsion was returned to 25°C, yielding a resin particle dispersion containing dispersed resin particles with a volume average particle size of 195 nm. Ion-exchanged water was added to this resin particle dispersion to adjust the solids content to 20%, yielding an amorphous polyester resin particle dispersion (A1) containing dispersed particles of amorphous polyester resin (A).

[0135] (Preparation of Crystalline Polyester Resin Particle Dispersion (B1)) 1,10-decanedicarboxylic acid: 260 parts 1,6-Hexanediol: 167 parts Dibutyltin oxide (catalyst): 0.3 parts The above materials were placed in a heated and dried three-neck flask. The air in the flask was replaced with nitrogen gas to create an inert atmosphere, and the mixture was stirred and refluxed at 180°C for 5 hours using mechanical stirring. The temperature was then gradually increased to 230°C under reduced pressure and stirred for 2 hours. Once the mixture reached a viscous state, it was air-cooled to terminate the reaction. This yielded a crystalline polyester resin with a weight-average molecular weight of 12,500 and a melting temperature of 73°C. 90 parts of the crystalline polyester resin, 1.8 parts of anionic surfactant (TaycaPower, manufactured by Tayca Corporation, 12% solids, sodium dodecylbenzenesulfonate), and 210 parts of ion-exchanged water were mixed, heated to 120°C, and dispersed using a homogenizer (IKA Ultra-Turrax T50). This was followed by a dispersion process using a pressure-discharge Gaulin homogenizer for 1 hour, yielding a resin particle dispersion containing resin particles with a volume average particle size of 195 nm. Ion-exchanged water was added to this resin particle dispersion to adjust the solid content to 20%, thereby obtaining a crystalline polyester resin particle dispersion (B1) in which crystalline polyester resin particles were dispersed.

[0136] (Preparation of styrene acrylic resin particle dispersion (S1)) Styrene: 375 parts n-Butyl acrylate: 25 parts Acrylic acid: 2 parts Dodecanethiol: 24 parts Carbon tetrabromide: 4 parts The mixture obtained by mixing and dissolving the above materials was dispersed and emulsified in a flask with a surfactant solution prepared by dissolving 6 parts of a nonionic surfactant (Nonipol 400, manufactured by Sanyo Chemical Industries, Ltd.) and 10 parts of an anionic surfactant (TaycaPower, manufactured by Tayca Corporation, 12% solids, sodium dodecylbenzenesulfonate) in 550 parts of ion-exchanged water. Next, an aqueous solution prepared by dissolving 4 parts of ammonium persulfate in 50 parts of ion-exchanged water was added to the flask over a 20-minute period while stirring. After nitrogen substitution, the contents of the flask were heated in an oil bath with stirring until the temperature reached 70°C, and the temperature was maintained at 70°C for 5 hours to allow emulsion polymerization to continue. This resulted in a resin particle dispersion containing resin particles with a volume-average particle size of 150 nm, a weight-average molecular weight (Mw) of 32,000, and a glass transition temperature (Tg) of 57°C. Ion-exchanged water was added to this resin particle dispersion to adjust the solids content to 20%, yielding a styrene-acrylic resin particle dispersion (S1) containing dispersed styrene-acrylic resin particles.

[0137] (Preparation of Colorant Particle Dispersion (Cy1)) CI Pigment Blue 15:3 (Dainichi Seika Color & Chemicals Mfg. Co., Ltd.): 70 parts Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 1 part Ion-exchanged water: 200 parts The above materials were mixed and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50 manufactured by IKA Corporation). Ion-exchanged water was added so that the solid content of the dispersion was 20%, and a colorant particle dispersion (Cy1) containing colorant particles with a volume average particle size of 190 nm was obtained.

[0138] (Preparation of release agent particle dispersion (W1)) Ester wax (pentaerythritol behenate wax, NOF Corp., product name WEP5, melting temperature 76°C): 100 parts Anionic surfactant: 1 part (TaycaPower, manufactured by Tayca Corporation, 12% solids, sodium dodecylbenzenesulfonate) Ion-exchanged water: 350 parts The above materials were mixed and heated to 100°C, dispersed using a homogenizer (IKA Ultra Turrax T50), and then dispersed using a pressure discharge Gaulin homogenizer to obtain a release agent particle dispersion liquid in which release agent particles with a volume average particle size of 1000 nm were dispersed. Ion-exchange water was added to this release agent particle dispersion liquid to adjust the solid content to 20%, and this was used as release agent particle dispersion liquid (W1).

[0139] (Preparation of Release Agent Particle Dispersion (W2)) First, in order to prepare the release agent particle dispersion (W2), the following samples were prepared. Polyethylene wax (hydrocarbon wax, Baker Petrolite's Polywax® 725, melting point 104°C): 270 parts Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 13.5 parts Ion-exchanged water: 21.6 parts Next, the above three samples were mixed, and a polyethylene wax (Polywax 725) was dissolved using a pressure discharge homogenizer (Gaulin Homogenizer manufactured by Gaulin Co., Ltd.), and the polyethylene wax (Polywax 725) was dispersed for 120 minutes at a pressure of 5 MPa, and then dispersed for 360 minutes at 40 MPa to obtain a mixed liquid. The obtained mixed liquid was cooled, and ion-exchanged water was added to adjust the solid concentration to 20.0%, to obtain a release agent particle dispersion liquid (W2). The volume average particle size of the particles in the resulting release agent particle dispersion (W2) was 225 nm.

[0140] <Toner Production> (Preparation of Toner 1) -Agglomerated particle formation process- Ion-exchanged water: 200 parts Colorant particle dispersion (Cy1): 15 parts Release agent particle dispersion (W1): 10.0 parts Styrene acrylic resin particle dispersion (S1): 107 parts Amorphous polyester resin particle dispersion (A1): 100 parts Crystalline polyester resin particle dispersion (B1): 10 parts Anionic surfactant (TaycaPower, manufactured by Tayca Corporation, solid content 12%, sodium dodecylbenzenesulfonate): 0.25 parts

[0141] The above materials were placed in a round stainless steel flask, and 0.1 N (0.1 mol / L) nitric acid was added to adjust the pH to 3.5. An aqueous magnesium chloride solution prepared by dissolving 6 parts of magnesium chloride in 30 parts of ion-exchanged water and an aqueous decyltrimethylammonium bromide solution prepared by dissolving 5.5 parts of decyltrimethylammonium bromide in 60 parts of ion-exchanged water were then added. The mixture was dispersed at 30°C using a homogenizer (IKA Ultra-Turrax T50), and then the temperature was raised. The mixture was heated to 45°C in a heating oil bath while the aggregate particle size was continuously monitored, and maintained at this temperature until the volume average particle size reached 4.9 μm, yielding primary aggregated particles (primary aggregated particle formation step).

[0142] To the dispersion containing the primary aggregated particles prepared as described above, 38 parts of styrene acrylic resin particle dispersion (S1) and 35 parts of amorphous polyester resin particle dispersion (A1) were slowly added as shell components, and the temperature of the heating jacket was further increased to 50°C and maintained at 50°C for 1 hour. 0.04 parts of ozone water (3 ppm, manufactured by Earthwalker Trading Co., Ltd.'s Ozone Buster Industry) was added to obtain secondary aggregated particles. The volume average particle size of the resulting secondary aggregated particles was measured and found to be 5.4 μm (secondary aggregated particle formation step). Thereafter, while continuing stirring, 20 parts of 10% EDTA (ethylenediaminetetraacetic acid) was added, and then the pH was adjusted to 9.0 with a 1N aqueous sodium hydroxide solution to stop aggregation.

[0143] -Fusion / unification process- Next, while continuing stirring, the temperature was increased to 85°C at a rate of 0.05°C / min, maintained at 85°C for 3 hours, and then cooled to 30°C at a rate of 15°C / min (first cooling). Next, the temperature was increased again to 85°C at a rate of 0.2°C / min, maintained for 30 minutes, and then cooled to 30°C at a rate of 0.5°C / min (second cooling). Next, the solid content was filtered off, washed three times with 500 mL of ion-exchanged water, and dried to obtain toner particles 1 having a volume average particle size of 5.2 μm.

[0144] -External addition of external additives- 100 parts of toner particles 1 and 1.5 parts of hydrophobic silica (RY50, manufactured by Nippon Aerosil Co., Ltd.) were mixed and mixed using a sample mill at a rotation speed of 10,000 rpm for 30 seconds. The mixture was sieved using a vibrating sieve with 45 μm openings to obtain toner 1.

[0145] (Preparation of Toners 2 to 18 and Toners C1 to C4) Toners 2 to 18 and Toners C1 to C4 were obtained in the same manner as Toner 1, except that the amounts of styrene acrylic resin particle dispersion (S1) ("StAc" in the table), amorphous polyester resin particle dispersion (A1) ("amorphous PES" in the table), crystalline polyester resin particle dispersion (B1) ("crystalline PES" in the table), release agent particle dispersion (W1) ("ester wax" in the table), release agent particle dispersion (W2) ("paraffin wax" in the table), anionic surfactant (sodium dodecylbenzenesulfonate) ("sulfur-containing solution" in the table), decyltrimethylammonium bromide ("bromine-containing compound" in the table), and ozone water used in the aggregate particle formation step were changed as shown in Table 1. The amounts of styrene acrylic resin particle dispersion (S1) and amorphous polyester resin particle dispersion (A1) listed in Table 1 are the total amounts added in the first aggregated particle formation step and the second aggregated particle formation step, and 74% of the total amount was used in the first aggregated particle formation step, and 26% of the total amount was used in the second aggregated particle formation step to produce the second aggregated particles.

[0146] <Measurement and Evaluation of Toner> (Toner Measurement) For the obtained toner, IBr, IS, and IO were determined by the above-mentioned methods, and the results are shown in Tables 2 and 3. Furthermore, the calculation results of IS / IBr and IBr / IO are shown in Tables 2 and 3.

[0147] (Preparation of developer) -Creating Carriers (CA)- 500 parts of spherical magnetite powder particles (volume average particle diameter 0.55 μm) were stirred in a Henschel mixer, and then 5 parts of a titanate-based coupling agent were added. The mixture was heated to 100 °C and stirred for 30 minutes. Next, 6.25 parts of phenol, 9.25 parts of 35% formalin, 500 parts of the magnetite particles treated with the titanate-based coupling agent, 6.25 parts of 25% aqueous ammonia, and 425 parts of water were added to a four-neck flask and stirred. The mixture was then allowed to react at 85 °C for 120 minutes while stirring. The mixture was then cooled to 25 °C, 500 parts of water was added, the supernatant liquid was removed, and the precipitate was washed with water. The washed precipitate was dried by heating under reduced pressure to obtain a carrier (CA) with an average particle size of 35 μm.

[0148] - Developer production - Each toner and a carrier (CA) were placed in a V blender at a mass ratio (toner / carrier) of 5 / 95 and stirred for 20 minutes to obtain each developer.

[0149] (Evaluation of toner color development) The color development of the toner was evaluated by determining the saturation of a color image, which was a cyan solid image. The output chart for evaluation was an image sample of Test Chart No. 5-1 of the Society of Electrophotography. Toner load: 4.5g / m 2 A total of 10 images were extracted, one for every 10 images, and the periphery of each image (10 mm from the edge) and 10 points inside the image were measured using an X-Rite 939 (aperture diameter 4 mm) manufactured by X-Rite Corporation, according to CIE 1976L. * a * b * Color coordinates (L * value, a * value, and b * value) and calculate the saturation (C * ) was calculated. * ) were evaluated according to the following evaluation criteria, and the results are shown in Tables 2 and 3. Formula:C * =((a *) 2 +(b * ) 2 ) 1 / 2

[0150] - Saturation (C * ) Evaluation criteria - A: 62≦C * (The saturation of colored images is well displayed without being affected.) A-:58≦C * <62 (color saturation is not impaired and is displayed well) B:54≦C * <58 (colored images are displayed with full saturation) B-:50≦C * <54 (colored images are displayed with full saturation) C:C * <50 (colored images are desaturated and degraded)

[0151] [Table 1]

[0152] [Table 2]

[0153] [Table 3]

[0154] From the above results, it can be seen that in this example, the saturation of the colored image is higher and the color development of the toner is better than in the comparative example.

[0155] This embodiment includes the following aspects. (((1))) toner particles containing a resin and a colorant; In the toner particles, when the net intensity of the Br element measured by fluorescent X-ray analysis is IBr and the net intensity of the S element measured by fluorescent X-ray analysis is IS, IBr is 1 kcps or more and 30 kcps or less, and IS / IBr is 0.005 or more and 1.2 or less, Toner for developing electrostatic images. (((2))) The toner for developing electrostatic images according to (((1))), wherein IBr / IO is 4.76 or more and 333 or less, where IO is the net intensity of O element in the toner particles measured by fluorescent X-ray analysis. (((3))) The toner for developing electrostatic images according to (((1))) or (((2))), wherein the IBr is 10 kcps or more and 25 kcps or less. (((4))) The toner for developing electrostatic images according to (((3))), wherein IS / IBr is 0.03 or more and 0.06 or less. (((5))) The toner for developing electrostatic images according to any one of (((2))) to (((4))), wherein IBr / IO is 83.3 or more and 143 or less. (((6))) The toner for developing electrostatic images according to any one of (((1))) to (((5))), wherein the resin includes a polyester resin. (((7))) The toner for developing electrostatic images according to any one of (((1))) to (((6))), wherein the toner particles contain a release agent containing an ester wax. (((8))) An electrostatic image developer comprising the toner for developing electrostatic images according to any one of (((1))) to (((7))). (((9))) The toner for developing electrostatic images according to any one of (((1))) to (((7))) is contained, A toner cartridge that is detachably attached to an image forming device. (((10))) a developing device that contains the electrostatic image developer according to (((8))) 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. (((11))) 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 (((8))) 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: (((12))) 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 (((8))); 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:

[0156] According to the invention related to (((1))), a toner for developing electrostatic images is provided which has good color development properties compared to when IBr is less than 1 kcps or more than 30 kcps, or when IS / IBr is less than 0.005 or more than 1.2. According to the invention related to (((2))), a toner for developing electrostatic images having good color development properties is provided compared to when IBr / IO is less than 4.76 or exceeds 333. According to the invention related to (((3))), a toner for developing electrostatic images is provided which has better color development properties than when the IBr is less than 10 kcps or more than 25 kcps. According to the invention related to (((4))), a toner for developing electrostatic images is provided which has better color development properties than when IS / IBr is less than 0.03 or exceeds 0.06. According to the invention related to (((5))), a toner for developing electrostatic images having good color development properties compared to when IBr / IO is less than 83.3 or more than 143 is provided. According to the invention related to (((6))), a toner for developing electrostatic images is provided which has better color development properties than when the resin is made of a styrene acrylic resin. According to the invention related to ((7)), there is provided a toner for developing electrostatic images which has better color development properties than when a release agent made of paraffin wax is contained. According to the inventions pertaining to (((8))), (((9))), (((10))), (((11))), or (((12))), there are provided an electrostatic image developer, a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method that are more likely to produce images with high saturation than when an electrostatic image developing toner having an IBr of less than 1 kcps or more than 30 kcps, or an IS / IBr of less than 0.005 or more than 1.2 is used. [Explanation of symbols]

[0157] 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 Photoconductor (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 117 Cabinet 118 Exposure opening 200 Process Cartridge 300 Recording paper (an example of a recording medium) P Recording paper (an example of a recording medium)

Claims

1. toner particles containing a resin and a colorant; In the toner particles, when the net intensity of the Br element measured by fluorescent X-ray analysis is IBr and the net intensity of the S element measured by fluorescent X-ray analysis is IS, IBr is 1 kcps or more and 30 kcps or less, and IS / IBr is 0.005 or more and 1.2 or less; Toner for developing electrostatic images.

2. 2. The toner for developing electrostatic images according to claim 1, wherein IBr / IO is 4.76 or more and 333 or less, where IO is the net intensity of O element in the toner particles measured by fluorescent X-ray analysis.

3. 2. The toner for developing electrostatic images according to claim 1, wherein the IBr is from 10 kcps to 25 kcps.

4. 4. The toner for developing electrostatic images according to claim 3, wherein IS / IBr is 0.03 or more and 0.06 or less.

5. 3. The toner for developing electrostatic images according to claim 2, wherein IBr / IO is 83.3 or more and 143 or less.

6. The toner for developing electrostatic images according to claim 1 , wherein the resin comprises a polyester resin.

7. 2. The toner for developing electrostatic images according to claim 1, wherein the toner particles contain a release agent containing an ester wax.

8. An electrostatic image developer comprising the toner for developing electrostatic images according to any one of claims 1 to 7.

9. A toner for developing electrostatic images according to any one of claims 1 to 7 is contained therein, A toner cartridge that is detachably attached to an image forming device.

10. a developing device containing the electrostatic image developer according to claim 8 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.

11. 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 8 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:

12. 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 8; 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