toner

Abstract

To provide a toner that can achieve both low temperature fixability and prevention of contamination of members for a long period even when the toner uses ester wax with high compatibility.SOLUTION: A toner has a toner particles. The toner particle contains a binder resin and ester wax. The ester wax is soluble by 2.0 pts.mass or more with 100.0 pts.mass of the binder resin at 100°C. An aggregate containing silica fine particles and a binding component is present on the surface of the toner particle. When the number ratio of toner particles having the aggregates is defined as CI (number%), the CI is 1 number% or more and 15 number% or less. When the number ratio of toner particles having the aggregates in a toner after processing under an ultrasonic condition A is defined as Ca (number%) and the number ratio of toner particles having the aggregates in the toner after processing under an ultrasonic condition B as Cb (number%), the CI, the Ca, and the Cb satisfy the formulas (1) and (2). An ultrasonic condition A: an output frequency of 30 kHz, an output capacitance of 0.75 W, and an irradiation time of 300 s. An ultrasonic condition B: an output frequency of 30 kHz, an output capacitance of 30 W, and an irradiation time of 300 s. Formula (1) 0.90≤Ca / CI≤1.00. Formula (2) 0.05≤Cb / CI≤0.25.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a toner used in a recording method using an electrophotographic method or the like.

Background Art

[0002] In recent years, image forming apparatuses such as copiers and printers have been diversified in their usage purposes and usage environments, and further energy saving and long life have been demanded. Although a number of means are known for image forming methods, the electrophotographic method is one of the main techniques among them. The process of the electrophotographic method is as follows. First, an electrostatic latent image is formed on an electrostatic charge image carrier (hereinafter also referred to as "photoconductor") by various means. Next, the latent image is developed with a developer (hereinafter also referred to as "toner") to form a visible image, and if necessary, after transferring the toner image to a recording medium such as paper, the toner image is fixed on the recording medium by heat or pressure or the like to obtain a copy. If the fixing temperature of the toner can be lowered, energy saving can be achieved. However, since the hardness of the toner that can be fixed at a low temperature generally decreases at room temperature, low-temperature fixability and durability tend to be in a trade-off relationship. For example, when an ester wax is used as a material for enhancing the meltability of the toner, although the low-temperature fixability is improved, the toner adheres to the members in the image forming apparatus over a long period of use, causing image defects. A number of techniques have been proposed to achieve both. For example, in Patent Document 1, a technique is disclosed in which member contamination on a conveyance roller or the like caused by adding an ester wax as a binder resin is made to coexist with low-temperature fixability by setting the number of carbon atoms of the ester wax and the heat generation peak by differential scanning calorimetry to specific values. Further, in Patent Document 2, a technique is disclosed in which in a toner containing a styrene-acrylic copolymer and an ester wax, low-temperature fixability and suppression of contamination in an image forming apparatus are made to coexist by setting the weight loss rate by thermogravimetric analysis within a specific range.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in recent years, the required level of achieving both long life and high image quality is extremely high, and it is difficult to say that the suppression of member contamination is sufficient even when using these technologies described in Patent Documents 1 and 2. An object of the present invention is to provide a toner that can achieve both low-temperature fixability and member contamination over a long period even when using a highly compatible ester wax.

Means for Solving the Problems

[0005] The present invention is a toner having toner particles, wherein the toner particles contain a binder resin and an ester wax, the ester wax is compatible with 2.0 parts by mass or more with respect to 100.0 parts by mass of the binder resin at 100 °C, aggregates containing silica fine particles and a binding component are present on the surface of the toner particles, when the number ratio of the toner particles having the aggregates is defined as CI (number %), the CI is 1% by number or more and 15% by number or less, when the number ratio of the toner particles having the aggregates in the toner after being treated under the following ultrasonic condition A is defined as Ca (number %), and the number ratio of the toner particles having the aggregates in the toner after being treated under the following ultrasonic condition B is defined as Cb (number %), the present invention relates to a toner characterized in that the Ci, the Ca, and the Cb satisfy formulas (1) and (2). · Ultrasonic condition A: Output frequency 30 kHz, output power 0.75 W, irradiation time 300 s · Ultrasonic condition B: output frequency 30 kHz, output power 30 W, irradiation time 300 s, 0.90 ≦ Ca / CI ≦ 1.00, Equation (1) 0.05 ≦ Cb / CI ≦ 0.25, Equation (2)

Advantages of the Invention

[0006] According to the present invention, even when an ester wax with high compatibility is used, it is possible to provide a toner that can achieve both low-temperature fixability and suppression of member contamination over a long period of time.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0008] In the present invention, the description of "XX or more and XX or less" or "XX to XX" representing a numerical range means a numerical range including the lower limit and the upper limit which are the endpoints, unless otherwise specified. Further, in the following description, the toner particles before the presence of agglomerates on the toner particle surface may be referred to as "toner core particles".

[0009] 〔Features of the Present Invention〕 The toner of the present invention is a toner having toner particles, the toner particles contain a binder resin and an ester wax, the ester wax is compatible with 2.0 parts by mass or more with respect to 100.0 parts by mass of the binder resin at 100 °C, Agglomerates containing silica fine particles and a binder component are present on the surface of the toner particles, when the percentage by number of toner particles having the agglomerates is defined as CI (number %), the CI is 1% by number or more and 15% by number or less, when the percentage by number of toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition A is defined as Ca (number %), and the percentage by number of toner particles having the agglomerates in the toner after being treated under the following ultrasonic condition B is defined as Cb (number %), it is characterized in that the Ci, the Ca, and the Cb satisfy formulas (1) and (2). · Ultrasonic condition A: output frequency 30 kHz, output power 0.75 W, irradiation time 300 s · Ultrasonic condition B: output frequency 30 kHz, output power 30 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.05 ≦ Cb / CI ≦ 0.25 Formula (2)

[0010] The inventors have found that, by adopting the above configuration, it is possible to suppress the occurrence of image defects associated with long-term use even in a toner having excellent low-temperature fixability using an ester wax. Although the details of the reason are unknown, it is presumed as follows.

[0011] The agglomerates disclosed in the present invention can maintain the state of being fixed to the toner under specific weak stresses and can be detached from the toner under specific intensities of stress. That is, in the toner that meets the requirements of the present invention, the agglomerates do not detach during the normal development process in the image forming apparatus, while the agglomerates can be detached in a development process with high stress where toner particles are deformed or cracked. Toner particles using ester wax are likely to be deformed or cracked due to high stress, and at such locations, the deformed or cracked toner adheres to the developing member. Once the toner adheres to the member, the adhesion of the toner further progresses in a chain reaction starting from there, causing image defects. However, the toner of the present invention can supply agglomerates containing silica fine particles and a binder component in a process where member contamination is likely to progress. In particular, since the toner is likely to crack at weak portions containing a large amount of ester wax, the ester wax is likely to be exposed on the fracture surface. Ester wax is a highly polar material and has a high affinity for silica composed of siloxane bonds. Therefore, when the agglomerates are supplied, the agglomerates quickly cover the above fracture surface. This is considered to suppress the chain-like adhesion of the toner and suppress member contamination. Such an effect can be expected to some extent even when silica fine particles are used as an external additive. However, since the external additive is embedded in the toner particles with durability, a sufficient effect cannot be obtained in long-term use. On the other hand, in the present invention, since the agglomerates containing silica fine particles and a binder component can be continuously supplied even in the latter half of durability, a sufficient effect can be obtained even in long-term use.

[0012] Hereinafter, the configuration of the toner of the present invention and preferred forms related to the toner will be described in detail. Note that the preferred forms are not limited to the present content.

[0013] 〔Agglomerates and Toner Particles〕 FIG. 1 is a representative view of a toner in which agglomerates are present on the surface of toner particles.

[0014] As the silica fine particles that are components of the agglomerates, for example, both so-called dry-process silica fine particles, which are produced by vapor-phase oxidation of silicon halides and are also called fumed silica, and so-called wet-process silica fine particles, which are produced from water glass or the like, can be used. These particles may be subjected to a hydrophobization treatment. Examples of the treatment agents used for the hydrophobization treatment include silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds. These may be used alone or in combination of two or more.

[0015] The number average particle diameter of the primary particles of the silica fine particles is preferably 5 nm or more and 300 nm or less (more preferably 10 nm or more and 200 nm or less). The number average particle diameter of the primary particles of the silica fine particles is preferably measured using a photograph of the toner taken at an enlarged scale with a scanning electron microscope.

[0016] As the binder component that binds the silica fine particles, those that can fix the particles with appropriate strength and do not cause any adverse effects even when subjected to environmental changes such as mechanical stress, temperature, and humidity in the developing process are required. Examples of such materials include organic resins. In particular, vinyl resins and polyester resins can be preferably used. These can hold the particles mainly composed of silica with appropriate fixing strength, and as the toner is used, it becomes possible to continuously supply the particles mainly composed of silica into the developing process. Also, although the binder component itself is simultaneously supplied into the developing process, by appropriately selecting the responsiveness of the binder component to environmental changes such as hardness, temperature, and humidity, it is possible to suppress member contamination and changes in developing characteristics. The content of the silica fine particles in the agglomerates is preferably 50% or more and 95% or less of the whole when observing the agglomerates with a backscattered electron image of a scanning electron microscope. Specific materials will be described in the section on the manufacturing method described later.

[0017] In the toner of the present invention, when the number ratio of toner particles having the agglomerates is defined as CI (number %), it is necessary that the CI is 1% by number or more and 15% by number or less. If the CI is too low, the number of agglomerates contained is too small, and thus the effects of the present disclosure cannot be obtained. If the CI is too high, the number of agglomerates contained is too large, and thus a large amount of agglomerates remain on the conductive member at the nip portion between the conductive roller and the photoreceptor, deteriorating the contamination of the conductive member. The CI is preferably 2% by number or more and 14% by number or less, and more preferably 3% by number or more and 12% by number or less. Further, the CI can be controlled by adjusting manufacturing conditions such as the number of charging parts of the material, the type of material, and stirring conditions.

[0018] Furthermore, in the toner of the present invention, when the number ratio of toner particles having the agglomerates in the toner after being processed under the following ultrasonic condition A is defined as Ca (number %), and the number ratio of toner particles having the agglomerates in the toner after being processed under the following ultrasonic condition B is defined as Cb (number %), it is necessary that the above CI, the Ca, and the Cb satisfy the relationships of formulas (1) and (2). · Ultrasonic condition A: Output frequency 30 kHz, output power 0.75 W, irradiation time 300 s · Ultrasonic condition B: Output frequency 30 kHz, output power 30 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.05 ≦ Cb / CI ≦ 0.25 Formula (2)

[0019] That is, the range of Ca / CI needs to be 0.90 or more and 1.00 or less. The fact that Ca / CI is smaller than 0.90 means that even weak-share agglomerates are likely to migrate. For this reason, the agglomerates are likely to be supplied to the blocking layer (a layer mainly composed of an external additive that stays on the opposite side of the advancing direction of the drum with respect to the contact surface between the drum of the photoreceptor and the cleaning blade and blocks the penetration of toner particles) all the time, so the effect does not last long and the conductive member is also likely to be contaminated. The preferable range of Ca / CI is 0.95 or more and 1.00 or less. Ca / CI can be controlled by adjusting the type of material such as silica fine particles and the binder component, and the respective compounding ratios.

[0020] The range of Cb / CI needs to be 0.05 or more and 0.25 or less. If Cb / CI is greater than 0.25, it means that it is difficult to transfer even in a high share of agglomerates, so it is difficult to obtain the effects of the present disclosure. The preferred range of Cb / CI is 0.11 or more and 0.21 or less. Cb / CI can be controlled by adjusting the material types of silica fine particles and binder components, and their respective compounding ratios.

[0021] Furthermore, it is preferable that the arithmetic mean value Ag of the Feret diameter of the agglomerates is 1000 nm or more and 8000 nm or less. If the agglomerates are within the above range, since the agglomerates are sufficiently large, it is easy to straddle between the domain and the matrix at the nip portion of the conductive member and the photoreceptor. More preferably, it is 1300 nm or more and 7500 nm or less, and still more preferably, it is 1500 nm or more and 7000 nm or less. The arithmetic mean value Ag of the Feret diameter of the agglomerates can be controlled by adjusting manufacturing conditions such as the particle diameter of the silica fine particles used, the number of charged parts, the compounding ratio of the silica fine particles and the binder component, and the stirring conditions.

[0022] Furthermore, on the surface where toner particles having the agglomerates are observed with a scanning electron microscope, it is preferable that the area ratio of the binder component of the agglomerates is 5% or more and 50% or less with respect to the entire aggregate. As described above, when the agglomerates appropriately contain the binder component, the transferability of the agglomerates is appropriately controlled, and the effects of the present disclosure can be obtained at a high level. If it is smaller than this range, the agglomerates are likely to transfer, easily contaminate the conductive member, and it is difficult to obtain the effects throughout the long life. If it is larger than this range, the agglomerates are difficult to transfer, and it is difficult to obtain the effect of improving cleaning failure. The area ratio of the binder component of the agglomerates can be controlled by adjusting manufacturing conditions such as the compounding ratio of the silica fine particles and the binder component, and the stirring conditions.

[0023] Furthermore, among the toner particles having the agglomerates, it is preferable that the ratio of the toner particles having the agglomerates satisfying the following (a) is 50% by number or more. (a) In a binarized image of a reflected electron image of an aggregate taken by a scanning electron microscope, when 18 straight lines are drawn at 10° intervals so as to pass through the midpoint of the image of the aggregate, the number A of straight lines having a line segment with a continuous dark part length of 100 nm or more on the straight line is 12 or more with respect to the total 18 straight lines.

[0024] Satisfying the above (a) means that the binding component is evenly dispersed in the aggregate. Therefore, since the migration of the aggregate is less likely to vary, the effects of the present disclosure are easily obtained. The proportion of toner particles having aggregates satisfying the above (a) is preferably 60% or more by number, more preferably 80% or more by number.

[0025] Incidentally, the number A of straight lines is more preferably 13 or more with respect to the total 18 straight lines, and even more preferably 15 or more.

[0026] As means for controlling the number of toner particles having aggregates satisfying the above (a), it can be controlled by adjusting production conditions such as the mixing ratio of silica fine particles and the binding component, and the dispersion conditions of the silica fine particles and the binding component used.

[0027] 〔Constituent components of toner particles other than aggregates〕 <Binding resin> The toner particles of the present invention contain a binder resin. The binder resin is not particularly limited, and known ones can be used. For example, homopolymers of aromatic vinyl compounds such as polystyrene and polyvinyltoluene and their derivatives; styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-butyl acrylate copolymers, styrene-octyl acrylate copolymers, styrene-dimethylaminoethyl acrylate copolymers, styrene-methyl methacrylate copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-dimethylaminoethyl methacrylate copolymers, styrene-vinyl methyl ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers and other copolymers of aromatic vinyl compounds; homopolymers of aliphatic vinyl compounds such as polyethylene and polypropylene and their derivatives; vinyl resins such as polyvinyl acetate, polyvinyl propionate, polyvinyl benzoate, polyvinyl butyrate, polyvinyl benzoate, polyvinyl formate, polyvinyl butyral; vinyl ether resins; vinyl ketone resins; acrylic polymers; methacrylic polymers; silicone resins; polyester resins; polyamide resins; epoxy resins; phenolic resins; rosin, modified rosin, terpene resins and the like can be used. These can be used alone or in combination of two or more.

[0028] Examples of the polymerizable monomers that form the copolymer of the aromatic vinyl compound include the following. That is, styrene derivatives such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, and p-phenylstyrene can be mentioned.

[0029] Examples of the polymerizable monomer for forming an acrylic polymer include acrylic polymerizable monomers such as acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, ethyl dimethyl phosphate acrylate, ethyl diethyl phosphate acrylate, ethyl dibutyl phosphate acrylate, and 2-benzoyloxyethyl acrylate.

[0030] Examples of the polymerizable monomer for forming a methacrylic polymer include methacrylic polymerizable monomers such as methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, ethyl diethyl phosphate methacrylate, and ethyl dibutyl phosphate methacrylate.

[0031] As the polyester resin, those obtained by polycondensing the following carboxylic acid component and alcohol component can be used. Examples of the carboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid. Examples of the alcohol component include bisphenol A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerin, trimethylolpropane, and pentaerythritol.

[0032] Further, the polyester resin may be a polyester resin containing a urea group. It is preferable not to cap carboxyl groups such as at the ends as the polyester resin.

[0033] For the purpose of improving the viscosity change of the toner at high temperatures, the binder resin may have a polymerizable functional group. Examples of the polymerizable functional group include a vinyl group, an isocyanate group, an epoxy group, an amino group, a carboxyl group, and a hydroxy group.

[0034] Among these, styrene-based copolymers typified by styrene-butyl acrylate and polyester resins are particularly preferable in terms of developing properties, fixability, etc. The method for producing the polymer is not particularly limited, and known methods can be used.

[0035] <Ester wax> The toner particles of the present invention contain an ester wax as a release agent. The wax is compatible with 2.0 parts by mass or more with respect to 100 parts by mass of the binder resin at 100°C.

[0036] The compatible amount with respect to 100 parts by mass of the binder resin at 100°C is hereinafter also referred to as the "saturated compatible amount". The saturated compatible amount is a numerical value indicating how much the ester wax can be compatible with the binder resin, and it is considered to indicate the compatibility between the binder resin and the ester wax. Even if the amount of the ester wax contained in the toner particles is the same, the greater the saturated compatible amount of the ester wax, the greater the effect on low-temperature fixability. The saturated compatible amount of the ester wax is 2.0 parts by mass or more, preferably 5.0 parts by mass or more, and more preferably 10.0 parts by mass or more. On the other hand, the upper limit value of the saturated compatible amount is not particularly limited, but is preferably 100.0 parts by mass or less, more preferably 50.0 parts by mass or less, and even more preferably 45.0 parts by mass or less. These numerical ranges can be arbitrarily combined. When the saturated compatible amount satisfies the above conditions, a sufficient plasticizing effect of the ester wax on the binder resin can be obtained, and good low-temperature fixability is exhibited.

[0037] The melting point of the ester wax is preferably 55°C or higher and 100°C or lower, more preferably 60°C or higher and 100°C or lower, and even more preferably 60°C or higher and 90°C or lower. When the melting point of the ester wax is 55°C or higher, it is less likely to adhere to the fixing roller during fixing, and when it is 100°C or lower, sufficient low-temperature fixability can be obtained.

[0038] The ester wax is not particularly limited as long as it satisfies the above conditions, and known ones can be used. For example, an ester wax that is a condensate of an alcohol component and a carboxylic acid component is preferable because it has excellent compatibility with the styrene-acrylic acid copolymer contained in the binder resin or the polyester moiety.

[0039] More specifically, as the ester wax, a condensate of an aliphatic monoalcohol having 18 to 22 carbon atoms and an aliphatic monocarboxylic acid having 18 to 22 carbon atoms; a condensate of an aliphatic monoalcohol having 18 to 22 carbon atoms and an aliphatic dicarboxylic acid or aromatic dicarboxylic acid having 6 to 10 carbon atoms; a condensate of an aliphatic diol having 2 to 10 carbon atoms and an aliphatic monocarboxylic acid having 14 to 22 carbon atoms; a condensate of diethylene glycol and an aliphatic monocarboxylic acid having 18 to 22 carbon atoms can be mentioned.

[0040] Among these, diester wax, which is an ester compound of an aliphatic diol having 2 to 10 carbon atoms and an aliphatic monocarboxylic acid having 14 to 22 carbon atoms, is preferable, and diester wax, which is an ester compound of a diol having 2 to 6 carbon atoms and an aliphatic monocarboxylic acid having 14 to 22 carbon atoms, is more preferable.

[0041] Examples of the diol having 2 to 6 carbon atoms include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and the like.

[0042] Examples of the aliphatic monocarboxylic acid having 14 to 22 carbon atoms include myristic acid, palmitic acid, stearic acid, behenic acid, and the like.

[0043] Furthermore, ethylene glycol distearate, which is an ester wax of ethylene glycol and stearic acid, is particularly preferred.

[0044] Regarding the number of carbon atoms of the diol component and the number of carbon atoms of the monocarboxylic acid of the ester wax, they can be determined by analyzing toner particles by pyrolysis GC / MS. If necessary, derivatization with a methylating agent or the like can be performed in advance to facilitate the analysis.

[0045] The content of the ester wax is preferably 5.0 parts by mass or more and 30.0 parts by mass or less, more preferably 7.0 parts by mass or more and 30.0 parts by mass or less, and even more preferably 7.0 parts by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

[0046] If the content of the ester wax is within the above range, the plasticizing effect on the binder resin becomes better, and excellent low-temperature fixability is exhibited. Also, the plasticizing effect on the binder resin does not become excessive, and the viscosity of the binder resin during fixing does not decrease too much, so the adhesion to paper becomes good, and fixing winding is less likely to occur. Regarding the content of the ester wax, toner particles are dissolved using a solvent such as deuterated chloroform, 13 and it can be determined by performing C-NMR analysis.

[0047] <Other waxes> In order to improve the releasability of the toner particles of the present invention from paper, the toner particles may contain waxes other than the ester wax as necessary. The wax is not particularly limited, and the following waxes can be exemplified.

[0048] Aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, Fischer-Tropsch wax, paraffin wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or block copolymers thereof; saturated straight-chain fatty acids such as palmitic acid, stearic acid, montanic acid; unsaturated fatty acids such as brassidic acid, eleostearic acid, parinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, cerlyl alcohol, melissyl alcohol; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; saturated fatty acid bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bisstearic acid amide; unsaturated fatty acid amides such as ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide; aromatic bisamides such as m-xylene bisstearic acid amide, N,N'-distearyl isophthalic acid amide; aliphatic metal salts (commonly called metal soaps) such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate; waxes grafted with vinyl monomers such as styrene and acrylic acid to aliphatic hydrocarbon waxes. The wax can be used alone or in combination of two or more.

[0049] Among these, it is preferable to contain hydrocarbon wax.

[0050] The content of waxes other than ester wax is preferably 0.5 parts by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

[0051] <Colorant> The toner of the present invention can also use a colorant as needed. The colorant is not particularly limited, and for example, known ones shown below can be used.

[0052] Examples of yellow pigments include iron oxide yellow, naphthol yellow S, naphthol yellow G, Hansa yellow G, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, tartrazine lake, and other condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following can be mentioned.

[0053] C.I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, 180.

[0054] Examples of orange pigments include the following.

[0055] Permanent Orange GTR, pyrazolone orange, Balkan orange, benzidine orange G, Indanthrene Brilliant Orange RK, Indanthrene Brilliant Orange GK.

[0056] Examples of red pigments include red iron oxide, permanent red 4R, rhodamine red, pyrazolone red, watchung red calcium salt, lake red C, lake red D, brilliant carmine 6B, brilliant carmine 3B, eosine lake, rhodamine lake B, alizarin lake, and other condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, the following can be mentioned.

[0057] C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254.

[0058] Examples of the cyan pigment include copper phthalocyanine compounds and their derivatives such as alkali blue lake, victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, first sky blue, indanthrene blue BG, anthraquinone compounds, basic dye lake compounds, etc. Specifically, the following are included.

[0059] C.I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, 66.

[0060] Examples of the purple pigment include fast violet B and methyl violet lake.

[0061] Examples of the green pigment include pigment green B, malachite green lake, and final yellow green G. Examples of the white pigment include zinc white, titanium oxide, antimony white, and zinc sulfide.

[0062] Examples of the black pigment include carbon black, aniline black, non-magnetic ferrite, magnetite, and those toned to black using the above yellow-based colorant, red-based colorant, and blue-based colorant. These colorants can be used alone, mixed, or even in a solid solution state.

[0063] If necessary, the surface of the colorant may be treated with a substance that does not cause polymerization inhibition.

[0064] Note that the content of the colorant is preferably 1.0 to 15.0 parts by mass with respect to 100.0 parts by mass of the binder resin or polymerizable monomer.

[0065] <Charge control agent> The toner of the present invention can also use a charge control agent as needed. Known charge control agents can be used, but a charge control agent with a high triboelectric charging speed and the ability to stably maintain a certain triboelectric charge amount is preferred. Further, when toner particles are produced by a polymerization method, a charge control agent with low polymerization inhibitory properties and substantially no solubilized product in an aqueous medium is preferred.

[0066] As charge control agents, there are those that control the toner to be negatively charged and those that control it to be positively charged. Examples of those that control the toner to be negatively charged include the following.

[0067] That is, monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acid and dicarboxylic acid-based metal compounds, aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthenic acid-based compounds, boron compounds, quaternary ammonium salts, calixarenes, resin-based charge control agents can be mentioned.

[0068] On the other hand, examples of those that control the toner to be positively charged include the following.

[0069] That is, nigrosine denatured products such as nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthalenesulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts which are analogs of these, and their lake pigments, triphenylmethane dyes and their lake pigments (as lake-forming agents, phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids, resin-based charge control agents can be mentioned.

[0070] The above charge control agent can be used alone or in combination of two or more. Among these charge control agents, metal-containing salicylic acid compounds are preferred, and those in which the metal is aluminum or zirconium are particularly preferred.

[0071] The addition amount of the charge control agent is preferably 0.1 part by mass or more and 20.0 parts by mass or less, more preferably 0.5 part by mass or more and 10.0 parts by mass or less, based on 100.0 parts by mass of the binder resin.

[0072] Also, as the charge control resin, it is preferable to use a polymer or copolymer having a sulfonic acid group, a sulfonate group or a sulfonic acid ester group. As the polymer having a sulfonic acid group, a sulfonate group or a sulfonic acid ester group, it is particularly preferable to contain a sulfonic acid group-containing acrylamide-based monomer or a sulfonic acid group-containing methacrylamide-based monomer in a copolymerization ratio of 2% by mass or more. More preferably, it is contained in a copolymerization ratio of 5% by mass or more. The charge control resin preferably has a glass transition temperature (Tg) of 35°C or higher and 90°C or lower, a peak molecular weight (Mp) of 10,000 or higher and 30,000 or lower, and a weight average molecular weight (Mw) of 25,000 or higher and 50,000 or lower. When this charge control resin is used, preferable triboelectric charging characteristics can be imparted without affecting the thermal characteristics required for toner particles. Furthermore, since the charge control resin contains a sulfonic acid group, the dispersibility of the charge control resin itself and the dispersibility of the colorant in the colorant dispersion are improved, and the coloring power, transparency, and triboelectric charging characteristics can be further improved.

[0073] 〔External additive〕 The toner of the present invention can also use an external additive as needed. Thereby, for example, fluidity, chargeability, cleanability, etc. can be controlled.

[0074] Examples of the external additives to be used in combination include inorganic oxide fine particles such as silica fine particles, alumina fine particles, and titanium oxide fine particles, inorganic stearic acid compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, or inorganic titanate compound fine particles such as strontium titanate and zinc titanate. These external additives to be used in combination can be used singly or in combination of two or more.

[0075] The total addition amount of these external additives is preferably 0.05 parts by mass or more and 10.00 parts by mass or less, more preferably 0.1 parts by mass or more and 5.0 parts by mass or less, based on 100 parts by mass of the toner particles.

[0076] Known methods can be used for fixing the external additives to the surface of the toner particles. For example, fixing using a Henschel mixer (dry method) or a method of fixing by dispersing the toner particles and the external additives in a solvent and then aggregating them (wet method) can be mentioned.

[0077] In addition, when spherical silica particles are used as the external additive, it is a preferable form. Since it is difficult for spherical silica particles to be buried in the toner particles, when cracked toner particles become the starting point of member contamination, for the surface portion of the toner particles where the spherical silica particles originally exist, coating by agglomerates is less likely to occur, and as a result, the fracture surface due to cracking is preferentially coated with spherical silica particles. Therefore, the long-term suppression effect of member contamination becomes greater. Specifically, those containing silicon, having an average number particle diameter of primary particles of 50 nm or more and 300 nm or less, an average value of the shape factor SF-1 of 105 or more and 120 or less, and an average value of SF-2 of 100 or more and 130 or less are preferable.

[0078] As long as the above conditions are satisfied, the spherical silica particles are not particularly limited, and examples thereof include sol-gel silica particles, fused silica particles, organosilicon polymer particles, and those using these in combination. As the spherical silica particles, wet silica particles can be preferably used. Further, these particles may be surface-treated with a silane coupling agent, a titanium coupling agent, silicone oil, or the like.

[0079] Among them, it is preferable to contain hydrotalcite as an external additive. By containing hydrotalcite having an opposite-polarity charge property with respect to the silica fine particles that are the main component of the agglomerates, the charge property of the toner, specifically, the charge rising property under a severe high-temperature and high-humidity environment, is improved. As a result, it becomes possible to suppress the occurrence of a low density due to long-term use.

[0080] 〔Method for manufacturing toner〕 Hereinafter, an example of a method for obtaining the above toner particles will be described, but it is not limited to the following.

[0081] The method for manufacturing toner particles is not particularly limited, and a suspension polymerization method, a dissolution suspension method, an emulsion aggregation method, a pulverization method, etc. can be used. As an example, a method for obtaining toner particles by the emulsion aggregation method will be described below.

[0082] <Method for manufacturing toner particles (toner core particles) by emulsion aggregation method> (Preparation step of resin fine particle dispersion) The resin fine particle dispersion can be prepared by a known method, but is not limited to these methods. For example, an emulsion polymerization method, a self-emulsification method, an inverse phase emulsification method in which an aqueous medium is added to a resin solution dissolved in an organic solvent to emulsify the resin, or a forced emulsification method in which the resin is forcibly emulsified by heat treatment in an aqueous medium without using an organic solvent can be mentioned.

[0083] As an example, a method for preparing a resin fine particle dispersion by the inverse phase emulsification method will be described below.

[0084] Dissolve the resin component in an organic solvent in which these are soluble, and add a surfactant or a basic compound. At that time, if the resin component is a crystalline resin having a melting point, it may be heated to a temperature above the melting point and dissolved. Subsequently, while stirring with a homogenizer or the like, an aqueous medium is slowly added to precipitate resin fine particles. Then, the solvent is removed by heating or reducing the pressure to prepare an aqueous dispersion of the resin fine particles.

[0085] Here, the organic solvent used to dissolve the resin component may be any one that can dissolve them. Specifically, toluene, xylene, etc. can be mentioned.

[0086] As the surfactant used during the preparation process, there are anionic surfactants such as sulfate ester salts, sulfonate salts, carboxylate salts, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; non-ionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols, etc.

[0087] As the basic compound used during the preparation process, there are inorganic bases such as sodium hydroxide and potassium hydroxide; organic bases such as ammonia, triethylamine, trimethylamine, dimethylaminoethanol, and diethylaminoethanol. The basic compound may be used alone or in combination of two or more.

[0088] (Preparation of the colorant dispersion) For the preparation of the colorant dispersion, known dispersion methods can be used. For example, general dispersion means such as a homogenizer, ball mill, colloid mill, ultrasonic disperser, etc. can be used, and there is no limitation. Also, as the surfactant used during dispersion, the surfactants mentioned above can be mentioned.

[0089] (Preparation of the wax dispersion) When preparing the wax dispersion, after dispersing the wax together with a surfactant, basic compound, etc. in water, it is heated to a temperature above the melting point of the wax, and at the same time, a homogenizer or disperser that applies a strong shear force is used for dispersion treatment. By going through such a process, a wax dispersion can be obtained. As the surfactant used during dispersion, the surfactants mentioned above can be mentioned. Also, as the basic compound used during dispersion, the basic compounds mentioned above can be mentioned.

[0090] (Agglomerated particle formation step) In the aggregated particle formation step, first, a resin fine particle dispersion, a colorant dispersion, a wax dispersion, etc. are mixed to obtain a mixed solution. Next, while heating at a temperature below the melting point of the resin fine particles, the pH is made acidic to cause aggregation, and aggregated particles containing resin fine particles, colorant particles, and release agent particles are formed to obtain an aggregated particle dispersion.

[0091] (First fusion step) In the first fusion step, under stirring conditions similar to those in the aggregated particle formation step, the progress of aggregation is stopped by raising the pH of the aggregated particle dispersion, and heating is performed at a temperature above the melting point of the resin component to obtain a fused particle dispersion.

[0092] (Amorphous resin fine particle adhesion step) In the amorphous resin fine particle adhesion step, an amorphous resin particle dispersion is added to the fused particle dispersion, and the pH is lowered to attach amorphous resin particles to the surface of the fused particles to obtain a dispersion of resin-attached particles. Here, this coating layer corresponds to the shell layer formed through the shell layer formation step described later. Note that the amorphous resin fine particle dispersion can be produced according to the preparation step of the resin fine particle dispersion described above.

[0093] (Second fusion step) In the second fusion step, in accordance with the first fusion step, the progress of aggregation is stopped by raising the pH of the resin-attached particle dispersion, and heating is performed at a temperature above the melting point of the resin component to fuse the attached resin aggregated particles to obtain toner particles with a shell layer formed.

[0094] <Method for manufacturing toner particles having agglomerates> As a method for manufacturing toner particles having agglomerates containing silica fine particles and a binder component, from the viewpoint of uniformly aggregating the silica fine particles and the binder component, it is preferable to externally add them to the toner core particles in a wet manner. When obtaining toner particles having agglomerates containing silica fine particles and a binder component in a wet manner, (Step 1) A step of obtaining a toner core particle dispersion in which toner core particles are dispersed in an aqueous medium, and (Step 2) A polymerizable monomer (monomer) serving as silica fine particles and a binder resin component is mixed with the toner core particle dispersion liquid, and the monomer is polymerized in the toner core particle dispersion liquid to form agglomerates having silica fine particles and a binder resin on the toner core particles. It is preferably included.

[0095] In Step 1, as a method for obtaining the toner core particle dispersion liquid, there are mentioned a method of directly using a dispersion liquid of toner core particles produced in an aqueous medium, and a method of charging dried toner core particles into an aqueous medium and mechanically dispersing them. When dispersing dried toner core particles in an aqueous medium, a dispersion aid may be used.

[0096] As the dispersion aid, known dispersion stabilizers, surfactants, etc. can be used. Specifically, the following are mentioned as dispersion stabilizers.

[0097] Inorganic dispersion stabilizers such as tricalcium phosphate, hydroxyapatite, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina; organic dispersion stabilizers such as polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch.

[0098] Also, the following are mentioned as surfactants. Anionic surfactants such as alkyl sulfate esters, alkylbenzene sulfonates, fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxypropylene alkyl ethers; cationic surfactants such as alkylamine salts, quaternary ammonium salts.

[0099] In Step 1, the toner core particle dispersion liquid preferably has a solid content concentration adjusted to 10% by mass or more and 50% by mass or less.

[0100] In Step 2, the silica fine particles and the monomer serving as the binder component may be directly added to the toner core particle dispersion liquid, or a dispersion liquid in which the silica fine particles and the monomer are dispersed in advance may be added to the toner core particle dispersion liquid. As a means for dispersing the silica fine particles and the monomer, the dispersion aids exemplified in the section of Step 1 can be used.

[0101] Examples of the binder component include polymers composed of monofunctional polymerizable monomers or polyfunctional polymerizable monomers, copolymers obtained by combining two or more of these, and mixtures thereof.

[0102] Examples of the polymerizable monomers include the following.

[0103] Styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene; acrylic polymerizable monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, ethyl acrylate dimethyl phosphate, ethyl acrylate diethyl phosphate, ethyl acrylate dibutyl phosphate, 2-benzoyloxyethyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, ethyl methacrylate diethyl phosphate, ethyl methacrylate dibutyl phosphate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropyl ketone; trifunctional silane compounds having a methacryloxyalkyl group as a substituent such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxyoctyltrimethoxysilane, γ-methacryloxypropyldiethoxymethoxysilane, γ-methacryloxypropylethoxydimethoxysilane; Trifunctional silane compounds having an acryloxyalkyl group as a substituent, such as γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxyoctyltrimethoxysilane, γ-acryloxypropyldiethoxymethoxysilane, γ-acryloxypropylethoxydimethoxysilane, etc.

[0104] Among them, from the viewpoint of high affinity with silica, it is preferable to use a trifunctional silane compound.

[0105] In step 2, silica fine particles and a monomer serving as a binder component are added to and mixed with the toner core particle dispersion liquid. At this time, it is preferable to adjust the temperature of the toner core particle dispersion liquid to a temperature suitable for the polymerization reaction. Then, while mixing the toner core particles, the silica fine particles and the monomer, a polymerization initiator is added to polymerize the added monomer, and agglomerates containing the silica fine particles and the binder component are externally added to the toner core particles to obtain a dispersion liquid of toner particles.

[0106] As the polymerization initiator, a known polymerization initiator can be used without particular limitation. Specifically, the following can be mentioned.

[0107] Peroxide-based polymerization initiators represented by hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxydicarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, tert-hydroperoxide of triphenylacetic acid, tert-butyl peroxyformate, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl N-(3-toluoyl)palmitate benzoyl peroxide, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, etc.; azo-based or diazo-based polymerization initiators represented by 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile, etc.

[0108] (Filtration process, washing process, drying process, classification process, external addition process) Thereafter, a filtration process for filtering out the solid content of the toner particles, a washing process if necessary, a drying process, and a classification process for adjusting the particle size are performed to obtain toner particles. The toner particles may be used as toner as they are. If necessary, the toner particles and external additives such as inorganic fine powders can be mixed and adhered using a mixer to obtain toner.

[0109] 〔Developer〕 The toner of the present invention can be used as a magnetic or non-magnetic one-component developer, or it may be mixed with a carrier and used as a two-component developer.

[0110] As the carrier, magnetic particles made of known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Among these, it is preferable to use ferrite particles. Further, as the carrier, a coated carrier in which the surface of the magnetic particles is coated with a coating agent such as resin, a resin-dispersed carrier in which magnetic fine powder is dispersed in a binder resin, or the like may be used.

[0111] As the carrier, those having a volume average particle diameter of 15 μm or more and 100 μm or less are preferable, and those having a volume average particle diameter of 25 μm or more and 80 μm or less are more preferable.

[0112] [Measurement method of physical properties] Hereinafter, the measurement methods of the respective physical properties related to the toner of the present invention will be described.

[0113] [Method for confirming the structure of ester wax and binder resin contained in toner] The saturated solubility of ester wax with respect to 100 parts by mass of the binder resin at 100 °C is measured as follows.

[0114] First, the ester wax is taken out from the toner particles. The extraction of the ester wax in the toner particles is performed by separating the extract using THF by solvent gradient elution method. The preparation method is shown below.

[0115] Weigh 10.0 g of toner particles, put them in a cylindrical filter paper (No. 84 made by Toyo Roshi Kaisha, Ltd.), and place them in a Soxhlet extractor. Extract with 200 mL of THF as a solvent for 20 hours, and the solid obtained by desolventizing the extract is the THF-soluble component. The THF-soluble component contains ester wax. This is performed multiple times to obtain the required amount of THF-soluble component.

[0116] For the solvent gradient elution method, gradient preparative HPLC (LC-20AP high-pressure gradient preparative system manufactured by Shimadzu Corporation, SunFire preparative column 50 mm φ 250 mm manufactured by Waters) is used. The column temperature is 30 °C, the flow rate is 50 mL / min, and for the mobile phase, THF, chloroform, and toluene are appropriately selected as good solvents in a timely manner, and acetonitrile, acetone, methanol, and n-hexane are appropriately selected as poor solvents in a timely manner. A sample prepared by dissolving 0.02 g of the THF-soluble component in 1.5 mL of a good solvent is subjected to gradient preparative HPLC. The mobile phase starts from a composition of 100% poor solvent, and 5 minutes after sample injection, the ratio of the good solvent is increased by 4% per minute, and the composition of the mobile phase is made 100% good solvent over 25 minutes. The obtained fractions are dried to obtain ester wax. Which fraction interval is ester wax can be determined by 1 1H-NMR analysis, 13 13C-NMR analysis, FT-IR analysis, GC-MS analysis, GPC analysis and other known analytical methods. By the said analytical methods, the types and structures of the ester wax in the toner particles can be identified.

[0117] Next, the binder resin is taken out from the toner particles. The binder resin is obtained by the separation operation by the said solvent gradient elution method. This is 1 1H-NMR analysis, 13 13C-NMR analysis, FT-IR analysis, GC-MS analysis, GPC analysis and other known analytical methods can identify the types and structures of the binder resin in the toner particles.

[0118] <Method for Measuring Saturated Solubility of Ester Wax and Binder Resin> Prepare the ester wax and binder resin obtained by the above operation. They may also be obtained by chemical synthesis from the obtained structures.

[0119] Weigh 1.00 g of the binder resin obtained by the said operation into a 30 mL vial and heat it to 100 °C. Then, add the ester wax to the vial, mix well at 100 °C and visually observe.

[0120] The compatibility is determined by visual observation. If it is transparent, it is judged to be compatible.

[0121] Add 0.005 g (0.5 parts by mass based on the binder resin) of ester wax one by one, and find the maximum amount that is judged to be compatible without becoming cloudy.

[0122] <Method for Confirming the Inclusion of Silica Fine Particles and Binder Components in Agglomerates> Regarding the confirmation of the inclusion of silica fine particles and binder components in the agglomerates, it is carried out using STEM-EDX and a scanning electron microscope.

[0123] First, for the toner having agglomerates, evaluate the cross-sectional structure and composition of the agglomerates using STEM-EDX.

[0124] Using an osmium plasma coater (Filgen, OPC80T), apply an Os film (5 nm) and a naphthalene film (20 nm) to the toner as a protective film, embed it with a photocurable resin D800 (JEOL), and then use an ultrasonic ultramicrotome (Leica, UC7) to produce a cross-section of toner particles with a film thickness of 100 nm at a cutting speed of 1 mm / s. At this time, a plurality of toners may be processed collectively to obtain 300 to 500 toner cross-sections. A schematic diagram of the cross-section of the toner having agglomerates is shown in Figure 2.

[0125] Perform STEM-EDX observation on the obtained cross-section using the STEM function of TEM-EDX (TEM: JEOL, JEM2800 (200 keV), EDX detector: JEOL, dry SD 100GV, EDX system: Thermo Fisher, NORAN SYSTEM7). The probe size of STEM is 1.0 nm, the observation magnification is 50 to 300k, the image size of EDX is 256×256 pixels, and it is acquired by adjusting the storage rate to 10,000 cps and integrating 50 frames. The observation location is set so that the field of view includes the agglomerates present in the outer peripheral part of the toner particles.

[0126] The presence of particles mainly composed of silica and a binding component in the agglomerates can be determined by confirming that a portion with a large amount of silicon and oxygen and a portion with a large amount of elements derived from the binding component are separately present at the same location. When a resin is used as the binding component, a large amount of carbon is observed.

[0127] Next, the toner having agglomerates is observed for a secondary electron image using a scanning electron microscope. The secondary electron image obtained from the SEM is also called a "composition image", and those with a smaller atomic number are detected darker and those with a larger atomic number are detected brighter.

[0128] Toner particles are generally resin particles mainly containing a composition mainly composed of carbon such as a resin component and a release agent. When silica fine particles or metal oxides are present on the surface of the toner particles, in the secondary electron image obtained from the SEM, the silica fine particles and metal oxides are observed as bright portions and the resin portion mainly composed of carbon is observed as a dark portion. The image capturing conditions are as follows.

[0129] (1) Sample preparation Stick carbon tape on the sample stage (aluminum sample stage 12.5 mm φ × 6 mm t), and place the toner on it. Further blow air to remove excess sample from the sample stage. Set the sample stage in the sample holder and set it in a scanning electron microscope (UltraPlus manufactured by Carl Zeiss).

[0130] (2) Electron microscope observation condition setting The confirmation of the presence of agglomerates containing silica fine particles and a binding component is performed using the image obtained by the secondary electron image observation of Ultra Plus. Since the image contrast changes according to the elemental composition in the secondary electron image, the presence of silica fine particles and the binding component in the agglomerates can be determined. The measurement conditions are shown below. Device used: ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd. Acceleration voltage: 0.7 kV WD: 2.0 mm Aperture Size: 30.0 μm Detection signal: EsB (energy-selective backscattered electrons) EsB Grid: 500V Contrast: 63.0 ± 5.0% (reference value) Brightness: 38.0 ± 5.0% (reference value) Resolution: 1024 × 768 Pretreatment: Sprinkle toner particles on carbon tape (no vapor deposition)

[0131] The contrast and brightness are appropriately set according to the state of the device used. Also, the acceleration voltage and EsB Grid are set to achieve items such as obtaining the surface structure information of the outermost layer of toner particles, preventing charge-up of the non-vapor-deposited sample, and selectively detecting high-energy backscattered electrons. The observation field of view is selected near the apex where the curvature of the toner particles is the smallest.

[0132] (3) Focus adjustment Set the observation magnification to 30000 (30k) times and adjust the Alignment and Stigma. Next, align the field of view with an area having a form that seems to be an agglomerate at an appropriate observation magnification. From the obtained backscattered electron image, it can be judged that it is the same as the agglomerate for which compositional observation was performed by STEM-EDX, having two types of contrasts, one corresponding to silica fine particles and the other corresponding to the binder component.

[0133] <Method for confirming the dispersion state of the binder component contained in the agglomerate> The dispersion state of the binder component contained in the agglomerate is calculated using the backscattered electron image of the agglomerate on the toner surface. The backscattered electron image of the agglomerate on the toner surface is obtained in the same manner as the method for obtaining the backscattered electron image of the toner surface.

[0134] Regarding the obtained backscattered electron image, the dispersion state of the binder component contained in the agglomerate is calculated using the image processing software ImageJ (developed by Wayne Rashand). The procedure is shown below.

[0135] First, convert the backscattered electron image to be analyzed to 8-bit from the Type in the Image menu. Next, from the Filters in the Process menu, set the Median diameter to 2.0 pixels to reduce image noise. Estimate the center of the image excluding the observation condition display section shown at the bottom of the backscattered electron image, and select a range of 1.5 μm square from the center of the backscattered electron image using the Rectangle Tool in the toolbar.

[0136] Next, select Threshold from Adjust in the Image menu. In manual operation, select all pixels corresponding to luminance B1 and click Apply to obtain a binary image. By this operation, the pixels corresponding to A1 are displayed in black (pixel group A1), and the pixels corresponding to A2 are displayed in white (pixel group A2). Again, estimate the center of the image excluding the observation condition display section shown at the bottom of the backscattered electron image, and select a range of 1.5 μm square from the center of the backscattered electron image using the Rectangle Tool in the toolbar.

[0137] Next, use the Straight Line in the toolbar to select the scale bar in the observation condition display section shown at the bottom of the backscattered electron image. When Set Scale in the Analyze menu is selected in this state, a new window opens, and the pixel distance of the selected line is input in the Distance in Pixels column.

[0138] Enter the value of the scale bar (for example, 100) in the Known Distance column of the window, enter the unit of the scale bar (for example, nm) in the Unit of Measurement column, and click OK to complete the scale setting.

[0139] Next, select Set Mesurements in the Analyze menu and check Area and Feret’s diameter. Select Analyze Particles in the Analyze menu, check Display Result, and click OK to perform domain analysis.

[0140] Subsequently, perform an Erode process for 10 pixels on the obtained analysis image using ImageJ, and then perform a Dilate process for 10 pixels using ImageJ. Note that the Erode process and the Dilate process are performed from the Binary item in the Process menu. Fig. 3 illustrates an image obtained by performing the above processes.

[0141] For the analysis image obtained after the above process, using the straight line tool (Straight Line) in the toolbar, with the midpoint of the analysis image as the reference point, draw a total of 18 straight lines at 10° intervals from one end of the image to the other end so as to pass through the reference point. Fig. 4 illustrates an image with line segments drawn.

[0142] Subsequently, measure the length L of a line segment where bright parts are continuous on the straight line, count the number of straight lines having a line segment with the length L of 100 nm or more, and check whether the number of such straight lines in the agglomerate is 12 or more.

[0143] <Method for confirming the ratio of toner particles having an agglomerate with 12 or more straight lines> For 30 toner particles having agglomerates contained in the toner to be evaluated, perform the above procedure on the agglomerates, count the number of toner particles having an agglomerate with 12 or more straight lines, and calculate the ratio A of toner particles containing an agglomerate with 12 or more straight lines from the following formula. A = {(the number of toner particles containing an agglomerate with 12 or more straight lines) / 30}

[0144] <Method for observing toner and method for calculating the number of toner particles> The toner is observed using a scanning electron microscope (SEM). The SEM apparatus and observation conditions are as follows. Apparatus used: ULTRA PLUS manufactured by Carl Zeiss Microscopy GmbH Acceleration voltage: 1.0 kV WD: 2.0 mm Aperture Size: 30.0 μm Detection signal: SE2 (secondary electron) Observation magnification: 2,000 times Contrast: 45.0 ± 5.0% (reference value) Brightness: 38.0 ± 5.0% (reference value) Resolution: 1024 × 768 Pretreatment: Sprinkle toner particles on carbon tape (no evaporation is performed)

[0145] The contrast and brightness are appropriately set according to the state of the apparatus used. Also, the acceleration voltage is set so as to achieve items such as acquisition of the structure information of the outermost surface of toner particles and prevention of charge-up of the non-evaporated sample.

[0146] The number of observation fields is observed up to the number of fields where the number of toner particles in which the entire particle is within the observation field in the obtained secondary electron image is counted, and when the number is designated as Tall (pieces), Tall is 300 pieces or more.

[0147] <Method for confirming the area ratio of the binder component contained in the agglomerate> The area ratio of the binder component is calculated based on the domain D1 of the binder component and the domain D2 that is not the binder component using the backscattered electron image of the agglomerate on the toner surface. The backscattered electron image of the agglomerate on the toner surface is obtained in the same manner as the method for obtaining the backscattered electron image of the toner surface.

[0148] The analysis of domains D1 and D2 is performed using the image processing software ImageJ (developer Wayne Rashand) on the backscattered electron image of the outermost surface of the toner particles obtained by the above method. The procedure is shown below.

[0149] First, convert the reflected electron image to be analyzed to 8-bit from the Type in the Image menu. Next, set the Median diameter to 2.0 pixels from the Filters in the Process menu to reduce image noise. Estimate the center of the image excluding the observation condition display section shown at the bottom of the reflected electron image, and select a range of 1.5 μm square from the center of the reflected electron image using the Rectangle Tool on the toolbar.

[0150] Next, use the Freehand selections function in the Image menu to select only the part where the carbon atom part of the mapping image coincides with the dark part of the reflected electron image, and fill it all with black. Also, fill all parts other than the part where the carbon atom part of the mapping image coincides with the dark part of the reflected electron image with white. Next, select Threshold from Adjust. In manual operation, select 128, which is the middle tone between black and white in an 8-bit image, as the threshold value, and click Apply to obtain a binary image.

[0151] By this operation, the pixels corresponding to domain D1 (binder component) are displayed in black (pixel group A1), and the pixels corresponding to domain D2 (other than the binder component) are displayed in white (pixel group A2).

[0152] Again, estimate the center of the image excluding the observation condition display section shown at the bottom of the reflected electron image, and select a range of 1.5 μm square from the center of the reflected electron image using the Rectangle Tool on the toolbar.

[0153] Next, use the Straight Line on the toolbar to select the scale bar in the observation condition display section shown at the bottom of the reflected electron image. When Set Scale in the Analyze menu is selected in this state, a new window opens, and the pixel distance of the selected straight line is input in the Distance in Pixels column.

[0154] Enter the value of the scale bar (e.g., 100) in the Known Distance column of the window, enter the unit of the scale bar (e.g., nm) in the Unit of Mesurement column, and click OK to complete the scale setting.

[0155] Subsequently, select Set Mesurements in the Analyze menu and check Area and Feret’s diameter. Select Analyze Particles in the Analyze menu, check Display Result and click OK to perform domain analysis.

[0156] From the newly opened Results window, obtain the area of each domain corresponding to domain D1 formed by pixel group A1 and domain D2 formed by pixel group A2.

[0157] Let the sum of the areas of domain D1 obtained be S1 (μm 2 ), and the sum of the areas of domain D2 be S2 (μm 2 ). Calculate the area ratio S of the binder component from the obtained S1 and S2 using the following formula. S (area %) = {S1 / (S1 + S2)} × 100

[0158] Perform the above procedure for 10 fields of view for the toner particles to be evaluated, and use the additive average value as the area ratio.

[0159] <Calculation method for the number CI of toner particles having agglomerates> In all the secondary electron images of the total number of fields of view obtained in the above observation, count the number of toner particles having agglomerates among the toner particles whose entire particles are within the observation field of view, and denote it as Tagg (pieces). Count the number of toner particles having agglomerates as shown in Fig. 1.

[0160] Calculate CI (number %) from the obtained Tall (pieces) and Tagg (pieces) using the following formula. CI (number %) = Tagg / Tall × 100

[0161] <Method for calculating the number of toner particles Ca and Cb having agglomerates when ultrasonic treatment is performed> Put about 10 ml of ion-exchanged water from which impurities and the like have been removed in advance into a glass container. Add about 0.5 ml of a dilution obtained by diluting "Contaminon N" (a 10% by mass aqueous solution of a neutral detergent for precision measuring instrument cleaning with a pH of 7 composed of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) about 3 times by mass with ion-exchanged water as a dispersant. Further add about 0.02 g of the measurement sample, and while stirring, perform the following dispersion treatment using an ultrasonic disperser to obtain a dispersion for measurement. At this time, appropriately cool so that the temperature of the dispersion becomes 10°C or higher and 40°C or lower. As the ultrasonic disperser, use an ultrasonic homogenizer with an oscillation frequency of 30 kHz (using "VP-050" (manufactured by TAITEC Co., Ltd.)), insert the vibrating part 1.0 cm into the dispersion, and vibrate under the following ultrasonic condition A or ultrasonic condition B. · Ultrasonic condition A: Output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s · Ultrasonic condition B: Output frequency 30 kHz, output capacity 30 W, irradiation time 300 s

[0162] Filter the dispersion obtained by the above procedure using a Kiriyama filter paper (No. 5C: pore diameter 1 μm) to separate the particles and the filtrate. Wash the obtained particles with 100 parts by mass of ion-exchanged water, and perform vacuum drying at 25°C for 24 hours to obtain a powder for measuring the number of toner particles Ca and Cb containing agglomerates.

[0163] Calculate Ca and Cb for the obtained powder by the same procedure as the "Method for calculating the number of toner particles CI having agglomerates", and check whether the relationships of the following formulas (1) and (2) are satisfied. 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.05 ≦ Cb / CI ≦ 0.25 Formula (2)

[0164] <Method for measuring the size of agglomerates and method for counting toner having agglomerates> In the above scanning electron microscope observation, photograph and save the entire toner at an appropriate magnification (5k - 10k). The image resolution shall be 1024×768 pixels.

[0165] From the obtained SEM images, select the portions determined to be agglomerates on the image using the image analysis software Image J (developed by Wayne Rasband). The size of the agglomerates is defined by the maximum Feret diameter of this selected area. The calculation procedure is shown below. a) Set the scale by [Analyze] - [Set Scale]. b) Check [Analyze] - [Set Measurements] - [Feret’s diameter]. c) Select [Freehand Selections] and manually select the agglomerates on the image. d) Select [Analyze] - [Measure] to obtain the maximum Feret diameter (Feret) of the selected portion. e) If there are multiple agglomerates on the image, repeat steps c) and d). f) Perform the same analysis for the remaining 9 images of the toner observed with agglomerates having a maximum Feret diameter of 500 nm or more. g) Take the maximum value of Feret (Feret diameter) of the obtained analysis results as the maximum Feret diameter. Those with a maximum Feret diameter of 500 nm or more are regarded as agglomerates.

[0166] Arbitrarily observe the toner with a scanning electron microscope, and let Ag be the arithmetic mean value of the maximum Feret diameters of a total of 100 agglomerates.

[0167] Also, let CI be the percentage of the number of toner particles having agglomerates among the arbitrarily observed toner particles.

[0168] <External additives SF - 1, SF - 2 and particle size measurement method> The external additives SF-1 and SF-2 were measured by observing the external additives on the toner surface with a scanning electron microscope (SEM) "S-4800" (manufactured by Hitachi, Ltd.). When the external additives are isolated, they may be directly observed. Specifically, in a field of view magnified 100,000 to 200,000 times, the maximum length, perimeter, and area of the external additives were evaluated using image processing software Image-Pro Plus 5.1J (manufactured by Media Cybernetics), and SF-1 and SF-2 were calculated by the following formulas. In this way, the average value of 100 external additives was obtained, and this was taken as the SF-1 and SF-2 of the external additives.

[0169] SF-1 = (maximum length of the external additive) 2 / (area of the external additive × π / 4) × 100 SF-2 = (perimeter of the external additive) 2 / (area of the external additive × 100 / 4π)

[0170] Similarly, the average value of the maximum length of 100 external additives was obtained, and this was taken as the particle size of the external additives.

[0171] [Configuration included in the embodiment of the present invention] The disclosure of this embodiment includes the following configurations. (Configuration 1) A toner having toner particles, wherein the toner particles contain a binder resin and an ester wax, the ester wax is compatible with 2.0 parts by mass or more with respect to 100.0 parts by mass of the binder resin at 100 °C, aggregates containing silica fine particles and a binding component are present on the surface of the toner particles, when the percentage of the number of toner particles having the aggregates is defined as CI (number %), the CI is 1% or more and 15% or less, when the percentage of the number of toner particles having the aggregates in the toner after being treated under the following ultrasonic condition A is defined as Ca (number %), and the percentage of the number of toner particles having the aggregates in the toner after being treated under the following ultrasonic condition B is defined as Cb (number %), the toner is characterized in that the CI, the Ca, and the Cb satisfy the relationships of formulas (1) and (2). · Ultrasonic condition A: output frequency 30 kHz, output power 0.75 W, irradiation time 300 s · Ultrasonic condition B: output frequency 30 kHz, output power 30 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Equation (1) 0.05 ≦ Cb / CI ≦ 0.25 Equation (2) (Configuration 2) The toner according to Configuration 1, wherein the binder resin is a resin containing a styrene acrylic acid copolymer. (Configuration 3) The toner according to Configuration 1, wherein the binder resin is a resin containing a polyester moiety. (Configuration 4) The toner according to any one of Configurations 1 to 3, wherein the arithmetic mean value Ag of the Feret diameter of the agglomerates is 1000 nm or more and 8000 nm or less. (Configuration 5) The toner according to any one of Configurations 1 to 4, wherein the toner has an external additive, and the external additive has spherical silica particles having a number average particle diameter of primary particles of 50 nm or more and 300 nm or less. (Configuration 6) The toner according to Configuration 5, wherein the external additive further has hydrotalcite particles. (Configuration 7) The toner according to any one of Configurations 1 to 6, wherein the ester wax is a diester wax. (Configuration 8) The toner according to Configuration 7, wherein the diester wax is an ester compound of a diol having 2 to 6 carbon atoms and a monocarboxylic acid having 14 to 22 carbon atoms.

Examples

[0172] The present invention will be specifically described by the following production examples and examples. However, these do not limit the present invention in any way. In the production examples and examples, "parts" are all based on mass unless otherwise specified.

[0173] <Preparation of Resin Particle Dispersion Liquid 1> 78.0 parts of styrene, 20.7 parts of butyl acrylate, 1.3 parts of acrylic acid as a carboxyl group-introducing monomer, and 3.2 parts of n-lauryl mercaptan were mixed and dissolved. To this solution, an aqueous solution prepared by dissolving 2.0 parts of sodium linear alkylbenzenesulfonate (product name: Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)) in 150 parts of ion-exchanged water was added in its entirety and dispersed.

[0174] While stirring slowly for another 10 minutes, an aqueous solution of 0.3 part of potassium persulfate and 10 parts of ion-exchanged water was added. After nitrogen substitution, emulsion polymerization was carried out at 70 °C for 6 hours. After the polymerization was completed, the reaction solution was cooled to room temperature, and ion-exchanged water was added to obtain Resin Particle Dispersion Liquid 1 with a solid content concentration of 12.5% by mass and a median diameter of 0.2 μm based on volume.

[0175] <Preparation of Resin Particle Dispersion Liquid 2> In a reaction tank equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple, monomers serving as an acid component and an alcohol component were introduced so as to have the following molar ratios. Terephthalic acid: 40.0 Isopropyl acrylate: 3.0 Trimellitic anhydride: 6.0 Propylene oxide adduct of bisphenol A (2 mol addition): 30.0 Ethylene oxide adduct of bisphenol A (2 mol addition): 10.0 Ethylene glycol: 6.0

[0176] 1.5 parts of dibutyltin was added as a catalyst based on 100 parts of the total amount of the monomers. Then, the temperature was quickly raised to 180 °C at normal pressure under a nitrogen atmosphere, and then water was distilled off while heating at a rate of 10 °C / hour from 180 °C to 210 °C to carry out polycondensation. After reaching 210 °C, the pressure inside the reaction tank was reduced to 5 kPa or less, and polycondensation was carried out under the conditions of 210 °C and 5 kPa or less to obtain Polyester Resin 1. At that time, the polymerization time was adjusted so that the softening point of the obtained Polyester Resin 1 would be 126 °C.

[0177] 100.0 parts of polyester resin 1 and 350 parts of ion-exchanged water were placed in a stainless steel container and heated to melt at 95 °C in a warm bath. Then, while stirring thoroughly at 7800 rpm using a homogenizer (Ultra Turrax T50 manufactured by IKA), 0.1 mol / L sodium hydrogen carbonate was added to make the pH greater than 7.0.

[0178] Thereafter, a mixed solution of 3.0 parts of sodium linear alkylbenzene sulfonate and 300 parts of ion-exchanged water was gradually added dropwise and emulsified and dispersed to obtain a polyester resin particle dispersion. The dispersion was cooled to room temperature, and ion-exchanged water was added to obtain Resin Particle Dispersion 2 with a solid content concentration of 12.5% by mass and a volume-based median diameter of 0.2 μm.

[0179] <Preparation of Release Agent Dispersion 1> 100 parts of a release agent (Fisher-Tropsch wax, melting point: 78 °C) and 15 parts of an aliphatic alcohol alkylene oxide adduct were mixed with 385 parts of ion-exchanged water, and dispersed using a wet jet mill JN100 (manufactured by Tokuyama Corporation) for about 1 hour to obtain a release agent dispersion. The concentration of the release agent dispersion was 20% by mass.

[0180] <Preparation of Release Agent Dispersions 2 to 6> Release agent dispersions 2 to 6 were obtained in the same manner except that the materials shown in Table 1 were used as the release agent. The concentration of the release agent dispersions was 20% by mass.

[0181]

Table 1

[0182] <Preparation of Colorant Dispersion 1> 100 parts of carbon black "Nipex 35 (manufactured by Orion Engineered Carbons)" as a colorant and 15 parts of an aliphatic alcohol alkylene oxide adduct were mixed with 885 parts of ion-exchanged water, and dispersed using a wet jet mill JN100 for about 1 hour to obtain a colorant dispersion.

[0183] <Preparation of Toner Core Particles 1> (Dispersion process) 265 parts of resin particle dispersion, 5 parts of mold release agent dispersion 1, 15 parts of mold release agent dispersion 2, 10 parts of colorant dispersion 1, 2.9 parts of aliphatic alcohol alkylene oxide adduct, and 0.6 part of sodium linear alkylbenzene sulfonate (Neogen RK) were dispersed using a homogenizer (Ultra Turrax T50 manufactured by IKA). While stirring, the temperature inside the container was adjusted to 30 °C, and an aqueous solution of 1 mol / L sodium hydroxide was added to adjust the pH to 8.0.

[0184] (Aggregation process) As a flocculant, an aqueous solution prepared by dissolving 0.08 part of aluminum chloride in 10 parts of ion-exchanged water was added over 10 minutes with stirring at 30 °C. After leaving it standing for 3 minutes, the temperature was raised, and the temperature was raised to 50 °C to form aggregated particles. In that state, the particle size of the aggregated particles was measured using a "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter). When the weight average particle size reached 7.0 μm, 0.9 part of sodium chloride and 5.0 parts of aliphatic alcohol were added to stop particle growth.

[0185] An aqueous solution of 1 mol / L sodium hydroxide was added to adjust the pH to 9.0, and then the temperature was raised to 95 °C to spheroidize the aggregated particles. When the average circularity reached 0.980, the temperature was lowered, and it was cooled to room temperature to obtain a dispersion of toner core particles 1.

[0186] <Preparation of toner core particles 2 to 16> In the preparation of toner core particles 1, dispersions of toner core particles 2 to 16 were prepared in the same manner except that resin particle dispersion 1 and mold release agent dispersion 2 were changed as shown in Table 2.

[0187]

Table 2

[0188] <Preparation of silica fine particles 1> In a 3 L glass reactor equipped with a stirrer, a dropping funnel, and a thermometer, 687.9 g of methanol, 42.0 g of pure water, and 47.1 g of 28% by mass aqueous ammonia were added and mixed. The temperature of the resulting solution was adjusted to 35 °C, and while stirring, 1100.0 g (7.23 mol) of tetramethoxysilane and 395.2 g of 5.4% by mass aqueous ammonia were simultaneously added. Tetramethoxysilane was added dropwise over 5 hours, and aqueous ammonia was added dropwise over 4 hours.

[0189] After the dropping was completed, stirring was continued for an additional 0.2 hours to perform hydrolysis, thereby obtaining a methanol - water dispersion of hydrophilic spherical sol - gel silica fine particles.

[0190] Next, an ester adapter and a condenser were attached to the glass reactor, and the above dispersion was heated to 65 °C to distill off methanol. Then, the same amount of pure water as the distilled - off methanol was added. This dispersion was dried at 80 °C under reduced pressure. The obtained silica fine particles were heated at 400 °C for 10 minutes in a thermostatic bath. The obtained silica fine particles (untreated silica) were crushed using a pulverizer (manufactured by Hosokawa Micron Corporation).

[0191] Thereafter, 50 g of silica fine particles were charged into a 1000 mL polytetrafluoroethylene inner - cylinder - type stainless - steel autoclave. After replacing the inside of the autoclave with nitrogen gas, while rotating the stirring blade attached to the autoclave at 400 rpm, 0.5 g of hexamethyldisilazane and 0.1 g of water were atomized by a two - fluid nozzle and uniformly sprayed onto the silica fine particles. After stirring for 30 minutes, the autoclave was sealed and heated at 200 °C for 2 hours. Subsequently, while heating, the system was depressurized to remove ammonia, and silica fine particles 1 were obtained. The number - average particle diameter of the primary particles of the obtained silica fine particles 1 was 100 nm.

[0192] <Preparation of Silica Fine Particles 2 - 6> In the preparation of the silica fine particles 1, 28 mass% aqueous ammonia was used in the amounts described in Table 3, and silica fine particles 2 to 6 were obtained in the same manner except that the dropping time of tetramethoxysilane and the stirring continuation time after the completion of dropping were changed to the conditions described in Table 3. The number average particle diameters of the obtained primary particles and SF-1 and SF-2 are shown in Table 3.

[0193]

Table 3

[0194] <Preparation Example of Monomer Dispersion Liquid 1 Having Silica Fine Particles and Binder Component> 70 parts of styrene, 20 parts of methacryloxypropyltrimethoxysilane, 10 parts of butyl acrylate, and 100 parts of silica fine particles 1 were dispersed using a homogenizer (Ultra Turrax T50 manufactured by IKA), the temperature in the container was adjusted to 25°C, and the mixture was stirred for 1 hour to obtain monomer dispersion liquid 1 having silica and a binder component.

[0195] <Preparation Examples of Monomer Dispersion Liquids 2 to 14 Having Silica Fine Particles and Binder Component> In the preparation of monomer dispersion liquid 1 having silica fine particles and a binder component, monomer dispersion liquids 2 to 14 having silica and a binder component were obtained in the same manner except that the amounts and material types were changed as described in Table 4.

[0196]

Table 4

[0197] <Preparation of Hydrotalcite Particles> A mixed aqueous solution (solution A) of 1.03 mol / L magnesium chloride and 0.239 mol / L aluminum sulfate, a 0.753 mol / L aqueous sodium carbonate solution (solution B), and a 3.39 mol / L aqueous sodium hydroxide solution (solution C) were prepared.

[0198] Next, liquid A, liquid B, and liquid C were added to the reaction tank using a metering pump at a flow rate such that the volume ratio of liquid A to liquid B was 4.5:1, and the pH value of the reaction solution was maintained in the range of 9.3 to 9.6 with liquid C. The reaction was carried out at a temperature of 40 °C to generate a precipitate. After filtration and washing, it was re-emulsified in ion-exchanged water to obtain a hydrotalcite slurry of the raw material. The hydrotalcite in the obtained hydrotalcite slurry had a concentration of 5.6% by mass. Thereafter, it was filtered through a membrane filter with a pore size of 0.5 μm and washed with ion-exchanged water. The obtained hydrotalcite was vacuum dried at 40 °C overnight and then subjected to a crushing treatment. The number average particle size of the obtained hydrotalcite was 400 nm.

[0199] Next, a toner production example will be described.

[0200] <Manufacture of Toner 1> To 100 parts of the toner core particle dispersion liquid, 3.0 parts of the monomer dispersion liquid obtained by the above method and 0.005 part of potassium persulfate were added, the temperature in the container was adjusted to 90 °C, and stirring was carried out for 2 hours using a full zone stirring blade to obtain a toner particle dispersion liquid 1.

[0201] Hydrochloric acid was added to the obtained toner particle dispersion liquid 1 to adjust the pH to 1.5 or less, and it was left to stir for 1 hour and then subjected to solid-liquid separation with a pressure filter to obtain a toner cake. This was re-slurried with ion-exchanged water to form a dispersion liquid again and then subjected to solid-liquid separation with the aforementioned filter. The re-slurrying and solid-liquid separation were repeated until the electrical conductivity of the filtrate became 5.0 μS / cm or less, and finally solid-liquid separation was carried out to obtain a toner cake. The obtained toner cake was dried and further classified using a classifier to obtain toner particles 1. The weight average particle size of the toner particles 1 was 7.0 μm.

[0202] As an external additive, · Fumed silica fine particles (number average particle size of primary particles: 10 nm, BET specific surface area: 170 m 2 / g) hydrophobized using dimethyl silicone oil (20% by mass): 0.7 part · Silica fine particles 1 as spherical silica particles: 0.5 part · Hydrotalcite particles: 0.1 part Together with 100 parts of toner particles, it was put into an FM mixer (FM10C type manufactured by Nippon Coke Industry Co., Ltd.) through which water at 7°C was passed in the jacket. After the water temperature in the jacket stabilized at 7°C ± 1°C, it was mixed for 5 minutes at a peripheral speed of 38 m / sec of the rotating blades to obtain Toner Mixture 1. At this time, the water flow rate in the jacket was appropriately adjusted so that the temperature inside the tank of the FM mixer did not exceed 25°C. The obtained Toner Mixture 1 was sieved with a mesh having an opening of 75 μm to obtain Toner 1.

[0203] The physical properties of the obtained Toner 1 are shown in Table 6.

[0204] <Production of Toners 2 to 9 and Comparative Toners 1 to 7> In the production of Toner 1, except that the number of parts, the types of materials, and the production conditions were changed as described in Table 5, Toners 2 to 9 and Comparative Toners 1 to 7 were obtained in the same manner.

[0205] The physical properties of the obtained Toners 2 to 9 and Comparative Toners 1 to 7 are shown in Table 6.

[0206]

Table 5

[0207]

Table 6

[0208] 〔Examples 1 to 9, Comparative Examples 1 to 7〕 Regarding the above-obtained Toners 1 to 9 and Comparative Toners 1 to 7, the following evaluations were respectively performed.

[0209] <Evaluation of Image Unevenness after Durability> Image unevenness is an image defect caused by member contamination and is an image defect that is easily observed when a full-surface halftone image is output. In particular, when the contamination becomes severe, white-out areas occur in the image.

[0210] An LBP712Ci (manufactured by Canon) refurbished model was used as the image forming apparatus. The process speed of the main body was modified to 250 mm / sec. Then, the necessary adjustments were made so that image formation was possible under this condition. Also, toner was removed from the black and cyan cartridges, and instead, 50 g of evaluation toner was filled in each, and durability was achieved by replenishing when the remaining amount reached less than 20 g. The toner loading amount was 1.0 mg / cm 2 was set.

[0211] The image streaks during continuous use in a normal temperature and humidity environment (23°C, 60% RH) were evaluated. As the evaluation paper, XEROX4200 paper (75 g / m 2 ) manufactured by XEROX was used.

[0212] In a normal temperature and humidity environment, intermittent continuous use of outputting 2 sheets of E-character images with a printing rate of 1% every 4 seconds was carried out for 30,000 sheets, and then 5 sheets of 50% halftone images and 100% solid images were continuously output on the entire surface, and the presence or absence of image unevenness in the 5th sheet was observed. A to C were judged as good. The evaluation results are shown in Table 7. (Evaluation criteria) A: No image unevenness occurred in both the halftone image and the solid image. B: Slight image unevenness occurred in the halftone image, but no image unevenness occurred in the solid image. C: Slight image unevenness occurred in both the halftone image and the solid image. D: Image unevenness with white voids occurred only in the halftone image. E: Image unevenness with white voids occurred in both the halftone image and the solid image.

[0213] <Evaluation of density reduction after durability> Density reduction is also an image defect caused by member contamination, which is an image defect where the image density becomes overall lighter when a 100% solid image is output.

[0214] An LBP712Ci (manufactured by Canon) modified device was used as the image forming apparatus. The process speed of the main body was modified to 250 mm / sec. And necessary adjustments were made so that image formation could be performed under this condition. Also, toner was removed from the black and cyan cartridges, and instead, 50 g of evaluation toner was filled in each, and durability was carried out by replenishing at the timing when the remaining amount reached less than 20 g. The toner loading amount was 1.0 mg / cm 2 was set.

[0215] The density change before and after continuous use in an environment of normal temperature and normal humidity (23°C, 60% RH) was evaluated. As the evaluation paper, XEROX4200 paper (75 g / m 2 ) manufactured by XEROX was used.

[0216] In an environment of normal temperature and normal humidity, an initial 100% solid image was printed, and then intermittent continuous use of outputting 2 sheets of E-character images with a printing rate of 1% every 4 seconds was carried out for 30,000 sheets. Then, a 100% solid image was output over the entire surface, and the presence or absence of density reduction was observed.

[0217] If image unevenness occurs in the full-surface solid image, avoiding it, the density was measured at 5 locations: the upper left corner, upper right corner, center, lower left corner, and lower right corner of the image using a Macbeth reflection densitometer (manufactured by Macbeth), and the average value was taken as the density.

[0218] A smaller density difference between before and after durability indicates a better evaluation. The evaluation criteria are as follows. A to C were judged as good. The evaluation results are shown in Table 7. (Index of density unevenness) A: Density difference is 0.03 or less B: Density difference is 0.04 or more and 0.05 or less C: Density difference is 0.06 or more and 0.07 or less D: Density difference is 0.08 or more and 0.09 or less E: Density difference is 0.10 or more

[0219] <Evaluation of fixability> As an image forming apparatus, a color laser printer (HP Color LaserJet 3525dn, manufactured by HP) modified so that the developing bias can be adjusted was used, and FOX RIVER BOND paper (110 g / m 2 ) with relatively large surface irregularities and basis weight was used for the fixing medium. The evaluation image was a line image. By applying a developing bias and setting the image density high, the amount of toner on the image was increased. Furthermore, by using thick paper with large surface irregularities, the toner in the concave portions of the paper and the lower layer of the toner layer becomes difficult to melt in the fixing process, so it is possible to severely evaluate peeling.

[0220] The evaluation procedure is shown below. First, the image forming apparatus was left overnight in a low temperature and low humidity environment (15°C, 10% RH). If the evaluation environment is low temperature, it is difficult for the fuser to warm up and the evaluation becomes severe. Then, using FOX RIVER BOND paper, a horizontal line image with a line width of 180 μm was printed by adjusting the developing bias. After leaving it in the low temperature and low humidity environment for 1 hour, a polypropylene tape (manufactured by tesa, Klebeband 19 mm × 10 mm) was attached to the horizontal line image and slowly peeled off. The image after peeling was visually observed and observed under a microscope, and evaluated according to the following evaluation criteria. A to B were judged to be good. The evaluation results are shown in Table 7. A: No defects B: Slight defects are visible, but not distinguishable by visual inspection C: Slight defects that can be recognized even visually are visible D: There are defects that can be recognized visually, and there are parts where the line is interrupted E: There are many interruptions in the line

[0221]

Table 7

Claims

1. A toner having toner particles, wherein the toner particles contain a binder resin and an ester wax, the ester wax is compatible with 2.0 parts by mass or more with respect to 100.0 parts by mass of the binder resin at 100 °C, aggregates containing silica fine particles and a binding component are present on the surface of the toner particles, when the number ratio of the toner particles having the aggregates is CI (number %), the CI is 1% by number or more and 15% by number or less, when the number ratio of the toner particles having the aggregates in the toner after being treated under the following ultrasonic condition A is Ca (number %), and the number ratio of the toner particles having the aggregates in the toner after being treated under the following ultrasonic condition B is Cb (number %), the toner is characterized in that the CI, the Ca, and the Cb satisfy the relationships of formulas (1) and (2). - Ultrasonic condition A: Output frequency 30 kHz, output capacity 0.75 W, irradiation time 300 s - Ultrasonic condition B: Output frequency 30 kHz, output capacity 30 W, irradiation time 300 s 0.90 ≦ Ca / CI ≦ 1.00 Formula (1) 0.05 ≦ Cb / CI ≦ 0.25 Formula (2)

2. The toner according to claim 1, wherein the binder resin is a resin containing a styrene-acrylic acid copolymer.

3. The toner according to claim 1, wherein the binder resin is a resin containing a polyester moiety.

4. The toner according to claim 1 or 2, wherein the arithmetic mean value Ag of the Feret diameter of the aggregates is 1000 nm or more and 8000 nm or less.

5. The toner according to claim 1 or 2, wherein the toner has an external additive, and the external additive has spherical silica particles having a number average particle diameter of primary particles of 50 nm or more and 300 nm or less.

6. The toner according to claim 5, wherein the external additive further has hydrotalcite particles.

7. The toner according to claim 1 or 2, wherein the ester wax is a diester wax.

8. The toner according to claim 7, wherein the diester wax is an ester compound of a diol having 2 to 6 carbon atoms and a monocarboxylic acid having 14 to 22 carbon atoms.

Images