Toner

Abstract

To provide a toner having charge rising property in a high temperature and high humidity environment and charge stability in a low temperature and low humidity environment and giving excellent image quality.SOLUTION: A toner comprising: toner particles containing a binder resin; and an external additive, wherein the external additive contains rutile-anatase type titania particles and hydrotalcite particles, and a rutile / anatase ratio of the rutile-anatase type titania particles, which is a ratio based on a peak intensity measured by a powder X-ray diffraction method, is 15 / 85 to 50 / 50.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to toners used in copying machines and printers that use electrophotography or electrostatic recording. [Background technology]

[0002] 2. Description of the Related Art In recent years, image forming apparatuses such as copiers and printers have been used for a variety of purposes and in a variety of environments, and are therefore required to be able to achieve stable image quality in any environment. In order to achieve stable image quality, for example, Patent Document 1 discloses that the charging property of the toner is improved by disposing an external additive having both positive and negative polarity, such as hydrotalcite particles, on the surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-194837 Summary of the Invention [Problem to be solved by the invention]

[0004] The hydrotalcite particles are charged with the opposite polarity to the toner, and easily act as a carrier, improving the toner's chargeability. By combining hydrotalcite with a material that imparts high fluidity to the toner, such as titania particles, it is possible to provide a toner with excellent charge buildup even in environments where chargeability tends to decrease, such as high-temperature, high-humidity environments, and to achieve stable image quality. To enhance the function of hydrotalcite as a carrier, the hydrotalcite needs to be in a state with a high degree of freedom on the toner surface. However, if the hydrotalcite is arranged with a high degree of freedom, the hydrotalcite often becomes concentrated, especially during long-term use. Furthermore, when hydrotalcite is used in combination with titania particles, the highly adhesive titania particles adhere to the hydrotalcite surface, which makes it easier for agglomerates of hydrotalcite to form via the titania particles, resulting in significant concentration of the hydrotalcite.

[0005] In particular, when hydrotalcite concentrates in an environment where electrostatic charge tends to increase, such as a low-temperature, low-humidity environment, the electrostatic charge becomes excessive, resulting in various image defects such as ghosting at the end of a long-term use period. To prevent this phenomenon, it is conceivable to increase the adhesion of hydrotalcite to the toner particle surface, but this would reduce the function of hydrotalcite as a carrier, thereby reducing the benefits of using hydrotalcite. Furthermore, when hydrotalcite and titania particles are used together, problems such as component contamination caused by the above-mentioned agglomerates are likely to occur. As described above, in a system using hydrotalcite particles and titania particles, a toner that can provide stable image quality in all environments has not yet been realized.

[0006] Therefore, the present disclosure provides a toner that contains hydrotalcite particles and titania particles, and that has charge rise properties in a high-temperature, high-humidity environment and charge stability in a low-temperature, low-humidity environment, and that can provide excellent image quality. [Means for solving the problem]

[0007] The present disclosure provides: A toner having toner particles containing a binder resin and an external additive, The external additive contains rutile-anatase type titania particles and hydrotalcite particles. The toner has a rutile / anatase ratio of the rutile-anatase titania particles, which is a ratio based on peak intensity measured by powder X-ray diffraction, of 15 / 85 to 50 / 50. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a toner that contains hydrotalcite particles and titania particles, and that has charge rise properties in a high-temperature, high-humidity environment and charge stability in a low-temperature, low-humidity environment, and that can provide excellent image quality. [Brief explanation of the drawings]

[0009] [Figure 1] Figure 1 shows the images used for ghost evaluation. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ. Note that when XX is a group, multiple XXs may be selected, and the same applies to YY and ZZ. In the present disclosure, the term (meth)acrylate means methacrylate and / or acrylate. In this disclosure, the term "monomer unit" refers to the reacted form of a monomer substance in a polymer. For example, in a polyester, one unit is defined as an ester bond. In calculating mole percent, one unit corresponds to one molecule.

[0011] As mentioned above, in a system using hydrotalcite particles and titania particles in combination, the hydrotalcite tends to concentrate, causing the problem of overcharging in low-temperature, low-humidity environments. One method for suppressing excessive charging is to incorporate a low-resistivity material such as titania particles into the toner. However, regular titania particles tend to be charged with the opposite polarity to the hydrotalcite particles, and are electrostatically attracted to the hydrotalcite fine particles. Therefore, this promotes the generation of hydrotalcite agglomerates via the titania particles, making it impossible to improve the concentration of the hydrotalcite. As a result of extensive research, the present inventors have found that using rutile-anatase type titania particles and hydrotalcite particles and controlling the rutile / anatase ratio of the rutile-anatase type titania particles to 15 / 85 to 50 / 50 is effective in preventing the generation of agglomerates and improving the concentration of the hydrotalcite particles.

[0012] That is, the present disclosure: A toner having toner particles containing a binder resin and an external additive, The external additive contains rutile-anatase type titania particles and hydrotalcite particles. The toner has a rutile / anatase ratio of the rutile-anatase titania particles, which is a ratio based on peak intensity measured by powder X-ray diffraction, of 15 / 85 to 50 / 50.

[0013] The reason why the above configuration is effective will be explained. In the present disclosure, rutile-anatase titania particles refer to titania particles containing rutile-type TiO2 and anatase-type TiO2. The rutile-anatase titania particles can suppress the aggregation of hydrotalcite due to the spacer effect of their shape. Furthermore, rutile-anatase type titania particles have a volume resistivity of about 15 / 85 to 50 / 50, which suppresses charge-up of hydrotalcite particles and electrostatic aggregation in a developing machine. A rutile / anatase ratio in the range of 15 / 85 to 50 / 50 indicates that the volume resistivity and shape are in an appropriate range. As a result, the effects of preventing the formation of agglomerates of hydrotalcite particles and titania particles and improving the concentration of hydrotalcite particles are obtained. Therefore, the above effects are achieved by using rutile-anatase type titania particles and hydrotalcite particles in combination and keeping the rutile / anatase ratio in the above range.

[0014] The toner will be described in more detail below. The toner of the present disclosure includes toner particles containing a binder resin and an external additive. The external additive contains rutile-anatase titania particles and hydrotalcite particles. The binder resin, toner particles, and external additive will be described later.

[0015] The rutile / anatase ratio of the rutile-anatase titania particles, which is a ratio based on peak intensity measured by powder X-ray diffraction, is 15 / 85 to 50 / 50. As described above, when the rutile / anatase ratio is in the above range, the volume resistivity and shape are in appropriate ranges. The rutile / anatase ratio is preferably 18 / 82 to 50 / 50, more preferably 18 / 82 to 48 / 52, and even more preferably 22 / 78 to 48 / 52. The rutile / anatase ratio can be adjusted by the time and sintering temperature when sintering anatase titanium oxide. For example, the rutile / anatase ratio decreases as the sintering time increases. Conversely, it increases as the sintering time decreases. Furthermore, the rutile / anatase ratio increases as the sintering temperature increases. Conversely, it decreases as the sintering temperature decreases.

[0016] The rutile / anatase ratio is measured by the following procedure. First, rutile-anatase titania particles are uniformly placed in a 0.5 mm diameter Boro-Silicate capillary (manufactured by W. Muller) to prepare a measurement sample. Then, the measurement sample is measured using the measurement conditions described later. Then, the obtained peaks are subjected to peak separation processing, and the intensity I of the strongest interference line (plane index 110) originating from rutile-type TiO2 is R and the intensity I of the strongest interference line (plane index 101) originating from anatase TiO2. A and measure the obtained intensity I R and I A From the above, the anatase content and rutile content in the rutile-anatase titania particles are calculated using the following formulas (2) and (3), and the rutile / anatase ratio is calculated using formula (4). Anatase content (%) = 100 / (1 + 1.265 × (I R / I A )) (2) Rutile content (%) = 100 - Anatase content (%) (3) Rutile / anatase ratio = rutile content / anatase content (4) A more specific procedure will be described later.

[0017] When the number average value of the major axis diameter of the primary particles of the rutile-anatase type titania particles is L1 (nm) and the number average value of the minor axis diameter of the primary particles of the rutile-anatase type titania particles is L2 (nm), the ratio L1 / L2 is preferably 1.0 to 5.0. Having L1 / L2 in the above range is preferred because it facilitates the exertion of the spacer effect. L1 / L2 is more preferably 1.5 to 4.0, and even more preferably 1.8 to 3.0. The L1 / L2 value can be adjusted by changing the crushing method and conditions used to obtain rutile-anatase titania particles. Specifically, the value can be increased by increasing the calcination time and calcination temperature of anatase titanium oxide. The value can also be decreased by decreasing the calcination time and calcination temperature of anatase titanium oxide. The L1 / L2 value is calculated by measuring L1 and L2 using the method described below.

[0018] The shape of the rutile-anatase type titania particles is not particularly limited, and may be any known shape such as needle-like, rod-like, plate-like, or spindle-like, but a spindle shape is preferred. The spindle shape is a shape that gradually becomes thinner toward both ends. A spindle shape is preferred because it tends to provide an appropriate contact area with the hydrotalcite particles.

[0019] The number average long axis diameter L1 of the primary particles of the rutile-anatase type titania particles is preferably 10.0 to 100.0 nm. When L1 is 10.0 nm or more, the spacer effect is easily exhibited, and when it is 100.0 nm or less, the chargeability is improved. L1 is more preferably 15.0 to 70.0 nm, and even more preferably 20.0 to 50.0 nm.

[0020] The number average minor axis diameter L2 of the primary particles of the rutile-anatase type titania particles may be 2.0 to 60.0 nm, and preferably 5.0 to 50.0 nm. When L2 is 5.0 nm or more, the spacer effect is easily exhibited, and when it is 50.0 nm or less, the chargeability is improved. L2 is more preferably 7.5 to 45.0 nm, and more preferably 10.0 to 25.0 nm.

[0021] The number-average major axis diameter L3 of the primary particles of the hydrotalcite particles may be 40 to 1100 nm, and preferably 40 to 1000 nm. When L3 is 40 nm or more, the hydrotalcite particles adhere well to the toner particles, making them less likely to detach during endurance testing, and further reducing contamination of the photoreceptor. When L3 is 1000 nm or less, the toner fluidity is likely to improve, resulting in better charging properties during endurance testing. L3 is more preferably 100 to 800 nm, and even more preferably 300 to 500 nm. The L3 value can be adjusted by changing the crushing means and conditions when obtaining the hydrotalcite particles. Specifically, the value can be increased by reducing the power required for the crushing step and shortening the processing time. The value can also be decreased by increasing the power required for the crushing step and extending the processing time. The method for measuring the L3 value will be described later.

[0022] In the toner, when the content of rutile-anatase titania particles per 100 parts by weight of toner particles is M1 (parts by weight), and the content of hydrotalcite particles per 100 parts by weight of toner particles is M2 (parts by weight), the ratio M1 / M2 is preferably 0.5 to 5.0. If the ratio M1 / M2 is less than 0.5, the amount of titania particles relative to the hydrotalcite particles is reduced. As a result, the fluidity of the toner is likely to decrease, and the charging performance during durability testing is likely to decrease. If the ratio M1 / M2 is greater than 5.0, the amount of titania particles relative to the hydrotalcite particles is increased. As a result, the titania particles inhibit contact between the hydrotalcite particles and the toner particles, which makes the hydrotalcite particles more likely to detach from the toner, causing contamination of components. The ratio M1 / M2 is more preferably 1.0 to 4.0, and even more preferably 1.5 to 3.0. The value of M1 / M2 can be adjusted by adjusting the amount of rutile-anatase titania particles and the amount of hydrotalcite particles added during toner production. The value of M1 / M2 is calculated using the values ​​obtained by measuring M1 and M2 using the method described below.

[0023] The value of M1 is not particularly limited, and may be 0.04 to 2.00 parts by mass, preferably 0.10 to 1.50 parts by mass, more preferably 0.25 to 1.00 parts by mass, and even more preferably 0.30 to 0.70. The value of M2 is not particularly limited, and may be 0.10 to 1.00 parts by mass, preferably 0.15 to 0.50 parts by mass, more preferably 0.15 to 0.40 parts by mass, and even more preferably 0.15 to 0.35.

[0024] When the number average value of the major axis diameter of the primary particles of the rutile-anatase type titania particles is L1 (nm) and the number average value of the major axis diameter of the primary particles of the hydrotalcite particles is L3 (nm), It is preferable that L1 / L3 is 0.030 to 0.900. If L1 / L3 is less than 0.030, the spacer effect is not easily exhibited and aggregation of the hydrotalcite is likely to occur. If L1 / L3 is more than 0.900, adhesion of the hydrotalcite particles to the toner particles is inhibited and they are likely to become detached. It is more preferable that L1 / L3 is 0.035 to 0.800, and even more preferably 0.050 to 0.300. The L1 / L3 value can be adjusted by adjusting the values ​​of L1 and L3 using the method described above. The L1 / L3 value is calculated using the values ​​obtained by measuring L1 and L3 using the method described below.

[0025] The volume resistivity ρV of rutile-anatase titania particles is 1×10 8 ~1×10 12 It is preferable that the volume resistivity is 1×10 Ω·cm. 8 A surface resistance of 1×10 Ω·cm or more is preferable because the titania particles are better charged. 12 If the resistance is Ω·cm or less, it is preferable because it is easy to suppress the charging of the hydrotalcite particles. 9 ~1×10 11 Ω·cm is more preferable, and 5×10 9 ~5×10 10 It is more preferable that the resistivity is Ω·cm. The value of ρV can be adjusted by the rutile / anatase ratio and the amount of hydrophobizing agent added. The method for measuring the value of ρV will be described later.

[0026] When the number average value of the major axis diameter of the primary particles of the rutile-anatase type titania particles is L1 (nm), the number average value of the minor axis diameter of the primary particles of the rutile-anatase type titania particles is L2 (nm), and the volume resistivity of the rutile-anatase type titania particles is ρV, it is preferable that L1, L2, and ρV satisfy the following formula (1): 2.4 ≦ (log 10(ρV)) / (L1 / L2) ≦ 8.0 (1) (log 10 The relationship between the volume resistivity and shape of rutile-anatase titania particles is expressed by (ρV) / (L1 / L2). Therefore, when the above formula (1) is satisfied, the relationship between the shape of each particle and the volume resistivity of the rutile-anatase titania particles is favorable, since it allows for a good balance between the spacer effect and the suppression of electrification and charge-up. Furthermore, L1, L2 and ρV more preferably satisfy the following formula (1-1), and even more preferably satisfy the following formula (1-2). 2.5 ≦ (log 10 (ρV)) / (L1 / L2) ≦ 7.0 (1-1) 3.0 ≦ (log 10 (ρV)) / (L1 / L2) ≦ 6.0 (1-2) (log 10 The value of (ρV) / (L1 / L2) can be adjusted by adjusting the values ​​of ρV, L1, and L2 using the method described above. 10 The value of (ρV) / (L1 / L2) is calculated using the values ​​obtained by measuring ρV, L1, and L2 by the method described below.

[0027] The binder resin preferably contains 50.0% by mass or more of polyester resin A, more preferably 70.0% by mass or more, even more preferably 90.0% by mass or more, and particularly preferably 95.0% by mass or more of polyester resin A. There are no particular upper limits, but examples include 50.0 to 100.0% by mass, 70.0 to 100.0% by mass, 90.0 to 100.0% by mass, 95.0 to 100.0% by mass, and 95.0 to 99.0% by mass.

[0028] The polyester resin A is not particularly limited, but is preferably a copolymer of a polycarboxylic acid and a polyol. The polycarboxylic acid preferably contains isophthalic acid. In this case, the polyester resin A preferably contains 60 mol% or more of monomer units corresponding to isophthalic acid based on the total monomer units corresponding to the polycarboxylic acid. The use of isophthalic acid can suppress charge accumulation in a low-temperature, low-humidity environment, and maintain good charge rise performance even in a high-temperature, high-humidity environment. The use of isophthalic acid is also preferable in terms of low-temperature fixability. Therefore, within the above range, the developability and the constant This is preferable as it tends to improve adhesion. The polyester resin A preferably contains 90 mol% or more of monomer units corresponding to isophthalic acid based on all monomer units corresponding to polycarboxylic acids. The upper limit is not particularly limited, and may be, for example, 60 to 100 mol%, or 90 to 100 mol%. The method for measuring the content of monomer units corresponding to isophthalic acid will be described later. The polyester resin A may use, as a raw material, the monomers described in the polyester resin section below.

[0029] The content ratio of the monomer units corresponding to isophthalic acid to all the monomer units corresponding to polycarboxylic acids in the polyester resin A is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, and even more preferably 90 to 100 mass%.

[0030] The toner particles preferably contain at least one selected from the group consisting of dodecylbenzenesulfonic acid and dodecylbenzenesulfonate salts. The sulfonic acid moiety of dodecylbenzenesulfonic acid and dodecylbenzenesulfonate salts is likely to coordinate with metal elements, which facilitates electron transfer within the toner particles. Examples of the salt include sodium salts and potassium salts, with sodium salts being preferred.

[0031] The binder resin preferably contains a polyester resin B, which has a monomer unit corresponding to at least one selected from the group consisting of an alcohol having an isosorbide structure and a carboxylic acid having an isosorbide structure. That is, the polyester resin B preferably has a monomer unit represented by the following formula (A): [ka] The monomer unit represented by the above formula (A) has an isosorbide structure. The isosorbide structure makes the toner surface highly polar, facilitating electrostatic attraction with the hydrotalcite. As a result, the concentration of the hydrotalcite can be suppressed. It is more preferable that the polyester resin B has a monomer unit corresponding to an alcohol having an isosorbide structure. The polyester resin B may be made from a monomer described in the polyester section below as a raw material. The content of polyester resin B in the binder resin is not particularly limited, but the binder resin preferably contains 0.5% by mass or more, and more preferably 1.0% by mass or more, of polyester resin B. The upper limit is not particularly limited, but may be, for example, 0.5 to 10% by mass, 1.0 to 10% by mass, or 1.0 to 5.0% by mass.

[0032] Each component constituting the toner and the method for producing the toner will be described in more detail below. <Rutile-anatase titania particles> The rutile-anatase titania particles can be produced by a known method. For example, ilmenite ore containing TiO2 is used as the starting material. After drying this raw material under specific conditions, sulfuric acid is added and dissolved to obtain an aqueous solution of TiO2. The pH of this aqueous solution is adjusted to neutralize it, and then filtered to obtain a white precipitate. Pure water is added to this white precipitate, and it is subjected to heat treatment for hydrolysis, followed by filtration and water washing. By repeating this process, anatase-type titanium oxide is obtained.

[0033] The resulting anatase-type titanium oxide is sintered by high-temperature heating, and by adjusting the sintering temperature and time, rutile-anatase-type titanium oxide with the desired rutile / anatase ratio is obtained. The sintering temperature is not particularly limited, but may be, for example, 800 to 1000° C., preferably 800 to 950° C., and more preferably 850 to 950° C. By setting the temperature within this range, it becomes easier to set the rutile / anatase ratio within the above range. The time is not particularly limited, but may be 1 to 10 hours, and more preferably 2 to 5 hours. By setting the time in this range, it becomes easier to set the rutile / anatase ratio in the above range.

[0034] If necessary, rutile-anatase type titanium oxide is crushed using a crushing means such as a jet mill to obtain rutile-anatase type titania particles of a desired particle size. The resulting rutile-anatase type titania particles may be surface-treated with a treating agent such as an alkoxysilane. That is, the rutile-anatase type titania particles are preferably treated with an alkoxysilane. This makes it easier to suppress aggregation of the rutile-anatase type titania particles. The alkoxysilane is not particularly limited, and known alkoxysilanes can be used. For example, trialkoxyalkylsilanes such as methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, and octyltrimethoxysilane are preferred. The number of carbon atoms in the alkyl group in the trialkoxyalkylsilane is not particularly limited, but may be, for example, 1 to 10, preferably 3 to 8, and more preferably 3 to 5. Among these, at least one selected from the group consisting of propyltrimethoxysilane, isobutyltrimethoxysilane, and octyltrimethoxysilane is preferred, and isobutyltrimethoxysilane is more preferred. The amount of alkoxysilane used for treatment may be 1 to 15 parts by mass, preferably 5 to 13 parts by mass, and more preferably 8 to 12 parts by mass, per 100 parts by mass of rutile-anatase type titania particles. Within this range, aggregation of the rutile-anatase type titania particles can be more easily suppressed.

[0035] <Hydrotalcite particles> The hydrotalcite particles can be those represented by the following composition formula (X): 2+ y M 3+ x (OH)2A n- (x / n) mH2O (X) where 0 <x≦0.5、y=1-x、m≧0である。 M 2+ , and M 3+ represent divalent and trivalent metals, respectively. M 2+ is preferably at least one divalent metal ion selected from the group consisting of Mg, Zn, Ca, Ba, Ni, Sr, Cu, and Fe. M 3+ is preferably at least one trivalent metal ion selected from the group consisting of Al, B, Ga, Fe, Co, and In. A n- is an n-valent anion, CO3 2- , O.H. - , Cl - , I - , F - , Br - , SO4 2- , HCO3 - , CH3COO - , and NO3 - These may be present alone or in combination.

[0036] Hydrotalcite particles are M 3+ It is preferable that the cations contain at least Al ions. 2+ It is preferable that the catalyst contains at least Mg ions. The hydrotalcite particles may be a solid solution containing a plurality of different elements, and may also contain a trace amount of a monovalent metal. The hydrotalcite particles preferably further contain aluminum, and more preferably contain magnesium and aluminum. It is preferable that the hydrotalcite particles contain fluorine. Furthermore, it is more preferable that the hydrotalcite particles contain fluorine inside. When fluorine is contained inside, the fluorine makes the charge of the hydrotalcite particles uniform, making it easier to suppress excess charge. The fact that the hydrotalcite particles contain fluorine inside is confirmed by line analysis in STEM-EDS mapping analysis.

[0037] <Other external additives> The toner may contain external additives other than the rutile-anatase titania particles and hydrotalcite particles. Specific examples of the external additives include inorganic fine particles and resin fine particles such as vinyl resins, polyester resins, and silicone resins. These external additives are preferably added by applying a shear force in a dry state.

[0038] <Binder resin> The toner particles contain a binder resin. The content of the binder resin in the toner particles is not particularly limited, but may be, for example, 80 to 99 parts by mass, or 82 to 95 parts by mass. The binder resin is not particularly limited, and examples thereof include polyester resin, vinyl resin, styrene-acrylic resin, epoxy resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, mixed resin or composite resin thereof, etc. The binder resin preferably contains at least one selected from the group consisting of polyester resin and styrene-acrylic resin, and more preferably contains styrene-acrylic resin.

[0039] The polyester resin can be obtained by selecting and combining suitable compounds from polycarboxylic acids, polyols, hydroxycarboxylic acids, etc., and synthesizing them using a known method such as transesterification or polycondensation.

[0040] Polycarboxylic acids are compounds containing two or more carboxy groups in one molecule, and among these, dicarboxylic acids are compounds containing two carboxy groups in one molecule and are preferably used. Examples of dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-carboxylic acid, hexahydroterephthalic acid, malonic acid, pimelic acid, suberic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediacetic acid, o-phenylenediacetic acid, diphenylacetic acid, diphenyl-p,p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracenedicarboxylic acid, and cyclohexanedicarboxylic acid. Among these, at least one selected from the group consisting of isophthalic acid and terephthalic acid is preferred.

[0041] Examples of polycarboxylic acids other than dicarboxylic acids include trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, pyrenetetracarboxylic acid, itaconic acid, glutaconic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid, isododecenylsuccinic acid, n-octylsuccinic acid, and n-octenylsuccinic acid. These may be used alone or in combination of two or more. Among these, trimellitic acid is preferred.

[0042] Polyols are compounds containing two or more hydroxyl groups in one molecule, and among these, diols are compounds containing two hydroxyl groups in one molecule and are preferably used. Specifically, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-Propylene glycol, 1,3-Propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosanedecanediol, dipropylene glycol, polyethylene glycol Examples of suitable bisphenols include glycerin, polypropylene glycol, polytetramethylene ether glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-butenediol, neopentyl glycol, 1,4-cyclohexanediol, polytetramethylene glycol, hydrogenated bisphenol A, bisphenol A, bisphenol F, bisphenol S, and alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above bisphenols.

[0043] The polyol is preferably at least one selected from the group consisting of alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferably alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms.

[0044] Examples of trivalent or higher polyols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, hexamethylolmelamine, hexaethylolmelamine, tetramethylolbenzoguanamine, tetraethylolbenzoguanamine, sorbitol, trisphenol PA, phenol novolac, cresol novolac, and alkylene oxide adducts of the above trivalent or higher polyphenols. These may be used alone or in combination of two or more. The polyester resin may also be a polyester resin containing a urea group. It is preferable that the carboxyl groups of the polyester resin, such as terminal groups, are not capped.

[0045] Examples of the styrene-acrylic resin include homopolymers made of the following polymerizable monomers, copolymers obtained by combining two or more of these, and mixtures thereof. Styrenic monomers such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene and p-phenylstyrene; (meth)acrylic monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-amyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, dimethyl phosphate ethyl (meth)acrylate, diethyl phosphate ethyl (meth)acrylate, dibutyl phosphate ethyl (meth)acrylate, and 2-benzoyloxyethyl (meth)acrylate, (meth)acrylonitrile, 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid, and maleic acid; Vinyl ether monomers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketone monomers such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; Polyolefins such as ethylene, propylene, and butadiene.

[0046] The styrene-acrylic resin may contain a polyfunctional polymerizable monomer, if necessary. Examples of the polyfunctional polymerizable monomer include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2'-bis(4-((meth)acryloxydiethoxy)phenyl)propane, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.

[0047] In order to control the degree of polymerization, it is also possible to further add a known chain transfer agent and polymerization inhibitor. Examples of the polymerization initiator for obtaining the styrene-acrylic resin include organic peroxide-based initiators and azo-based polymerization initiators. Examples of organic peroxide initiators include benzoyl peroxide, lauroyl peroxide, di-α-cumyl peroxide, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, bis(4-t-butylcyclohexyl)peroxydicarbonate, 1,1-bis(t-butylperoxy)cyclododecane, t-butylperoxymaleic acid, bis(t-butylperoxy)isophthalate, methyl ethyl ketone peroxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyisopropyl monocarbonate, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and tert-butylperoxypivalate. Among these, tert-butylperoxyisopropyl monocarbonate is preferred. Examples of the azo polymerization initiator include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobismethylbutyronitrile, and 2,2'-azobis-(methyl isobutyrate).

[0048] Furthermore, a redox initiator, which is a combination of an oxidizing substance and a reducing substance, can also be used as the polymerization initiator. The oxidizing substances include inorganic peroxides such as hydrogen peroxide, persulfates (sodium, potassium and ammonium salts) and oxidizing metal salts such as tetravalent cerium salts. Examples of reducing substances include reducing metal salts (divalent iron salts, monovalent copper salts, and trivalent chromium salts), ammonia, lower amines (amines having about 1 to 6 carbon atoms such as methylamine and ethylamine), amino compounds such as hydroxylamine, reducing sulfur compounds such as sodium thiosulfate, sodium hydrosulfite, sodium hydrogensulfite, sodium sulfite, and sodium formaldehyde sulfoxylate, lower alcohols (having 1 to 6 carbon atoms), ascorbic acid or a salt thereof, and lower aldehydes (having 1 to 6 carbon atoms). The polymerization initiator is selected with reference to its 10-hour half-life temperature and is used alone or in combination. The amount of polymerization initiator added varies depending on the desired degree of polymerization, but is generally 0.5 to 20.0 parts by mass per 100.0 parts by mass of polymerizable monomer.

[0049] <Crosslinking agent> In order to control the molecular weight of the binder resin constituting the toner particles, a crosslinking agent may be added during polymerization of the polymerizable monomer. For example, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, neopentyl glycol divinylbenzene, bis(4-acryloxypolyethoxyphenyl)propane, ethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol #200, #400, and #600 di(meth)acrylates, dipropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polyester di(meth)acrylate (trade name: MANDA, manufactured by Nippon Kayaku Co., Ltd.). The amount of the crosslinking agent added is preferably 0.001 to 15,000 parts by mass relative to 100 parts by mass of the polymerizable monomer.

[0050] <Release agent> The toner may contain a known wax as a release agent, for example, the toner particles preferably contain a wax. Specific examples include petroleum waxes such as paraffin wax, microcrystalline wax, and petrolatum and their derivatives, montan wax and its derivatives, hydrocarbon waxes produced by the Fischer-Tropsch process and their derivatives, polyolefin waxes such as polyethylene and polypropylene and their derivatives, natural waxes such as carnauba wax and candelilla wax and their derivatives, ester waxes, etc. Derivatives also include oxides, block copolymers with vinyl monomers, and graft modified products. Other examples include alcohols such as higher aliphatic alcohols, fatty acids such as stearic acid and palmitic acid or their acid amides, esters, and ketones, hydrogenated castor oil and its derivatives, vegetable waxes, and animal waxes.These may be used alone or in combination.

[0051] Among these, the use of hydrocarbon wax or ester wax tends to improve the developing property and fixing property, and is therefore preferred. That is, the wax preferably contains at least one selected from the group consisting of hydrocarbon wax and ester wax, and more preferably contains ester wax. Note that these waxes may contain an antioxidant to the extent that it does not affect the properties of the toner.

[0052] As described above, the toner particles preferably contain an ester wax. The ester wax can be used as a release agent as described above, and can also be used as a plasticizer. The ester wax is not particularly limited, and examples thereof include esters of monohydric alcohols and aliphatic carboxylic acids, such as behenyl behenate, stearyl stearate, and palmityl palmitate, or esters of monohydric carboxylic acids and aliphatic alcohols; esters of dihydric alcohols and aliphatic alcohols, such as ethylene glycol distearate, dibehenyl sebacate, and hexanediol dibehenate, or esters of dihydric carboxylic acids and aliphatic alcohols; esters of trihydric alcohols and aliphatic carboxylic acids, such as glycerin tribehenate, or esters of trihydric carboxylic acids and aliphatic alcohols; and pentaerythritol. Esters of tetrahydric alcohols and aliphatic carboxylic acids, such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate, or esters of tetrahydric carboxylic acids and aliphatic alcohols; esters of hexahydric alcohols and aliphatic carboxylic acids, such as dipentaerythritol hexastearate and dipentaerythritol hexapalmitate, or esters of hexahydric carboxylic acids and aliphatic alcohols; esters of polyhydric alcohols and aliphatic carboxylic acids, such as polyglycerol behenate, or esters of polyhydric carboxylic acids and aliphatic alcohols; and natural ester waxes, such as carnauba wax and rice wax. These may be used alone or in combination.

[0053] In addition, from the viewpoint of phase separation property with respect to the binder resin or crystallization temperature, preferred examples include higher fatty acid esters such as behenyl behenate and dibehenyl sebacate. Behenyl behenate is preferred. Behenyl behenate is preferred because the ester moiety and alkyl moiety of behenyl behenate facilitate interaction with titania particles and hydrotalcite particles. Therefore, among ester waxes, it is preferred because it tends to have better developability and fixability.

[0054] The content of the release agent is preferably 1.0 part by mass or more and 30.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin. The melting point of the release agent is preferably 30° C. or higher and 120° C. or lower, and more preferably 60° C. or higher and 100° C. or lower. By using a release agent with a melting point of 30° C. or higher and 120° C. or lower, the release effect is efficiently exerted and a wider fixing area is ensured.

[0055] <Coloring agent> The toner particles may contain a colorant. Examples of the colorant include the following: Examples of black colorants include carbon black, black magnetic materials, and those toned to black using a yellow colorant, a magenta colorant, and a cyan colorant. As the colorant, a pigment may be used alone, but it is more preferable to use a dye and a pigment in combination to improve the clarity from the viewpoint of the image quality of a full-color image.

[0056] Magenta colored pigments include the following: CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57:1, 58, 60, 63, 64, 68, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; CI Pigment Violet 19; CI Bat Red 1, 2, 10, 13, 15, 23, 29, 35.

[0057] Magenta-colored dyes include solvent dyes such as CI Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, and 121; CI Disperse Red 9; CI Solvent Violet 8, 13, 14, 21, and 27; and CI Disperse Violet 1; and basic dyes such as CI Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, and 40; and CI Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, and 28.

[0058] Cyan coloring pigments include the following: CI Pigment Blue 2, 3, 15:2, 15:3, 15:4, 16, 17; CI Vat Blue 6; CI Acid Blue 45; and copper phthalocyanine pigments having 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton. Cyan coloring dyes include CI Solvent Blue 70.

[0059] Yellow coloring pigments include the following: CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; CI Vat Yellow 1, 3, 20. Yellow coloring dyes include CI Solvent Yellow 162.

[0060] The content of the colorant is 0.1 to 30 parts by mass relative to 100 parts by mass of the binder resin. preferable.

[0061] <Charge control agent> The toner particles may contain a charge control agent. Examples of the charge control agent include the following: Organometallic compounds and chelate compounds are effective as charge control agents, and examples thereof include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Quaternary ammonium salts and resin-type charge control agents can also be used. Examples of resin-type charge control agents include resins having sulfonic functional groups such as sulfonic acid groups, sulfonate salt groups, and sulfonate ester groups, and resins having carboxy groups. Of these, resins having carboxy groups are preferred. These charge control agents can be used alone or in combination of two or more. The resin having a carboxy group is not particularly limited, but examples thereof include copolymers of a polymerizable monomer represented by the following formula (B) with other polymerizable monomers. [ka] As the other polymerizable monomer, for example, the polymerizable monomers described in the section explaining the styrene acrylic resin can be used, and among them, styrene is preferred.

[0062] The amount of the charge control agent to be added is preferably 0.01 to 20.00 parts by mass, and more preferably 0.50 to 10.00 parts by mass, relative to 100 parts by mass of the binder resin.

[0063] <Toner manufacturing method> The method for producing the toner is not particularly limited, and known methods such as a pulverization method, a suspension polymerization method, a solution suspension method, an emulsion aggregation method, and a dispersion polymerization method can be used. Here, the toner is preferably produced by the following method. That is, the toner is preferably produced by an emulsion aggregation method.

[0064] The toner manufacturing method includes the following steps (1) to (3): (1) a dispersion step of preparing a binder resin particle dispersion containing a binder resin; (2) an aggregation step of aggregating the binder resin fine particles contained in the binder resin fine particle dispersion to form aggregates; and (3) Fusion process in which the aggregates are heated to fuse them together It is preferable to have these in this order.

[0065] The toner manufacturing method further comprises the steps (4) and (5) below during or after the fusion step: (4) a spheronization step in which the agglomerates are further heated at an elevated temperature; (5) a cooling step of cooling the aggregate at a cooling rate of 0.1°C / second or more; and It is more preferable that the following be present in this order: When the toner is produced by the emulsion aggregation method, the polyester resin A is easily dispersed uniformly near the surface, and the toner shape can be controlled, which is preferable. Details of the emulsion aggregation method are described below.

[0066] <Emulsification aggregation method> The emulsion aggregation method is to prepare toner particles made of materials that are sufficiently small compared to the target particle size. In this method, an aqueous dispersion of fine particles is prepared in advance, the fine particles are aggregated in an aqueous medium until they reach the particle size of toner particles, and the resin is fused by heating or the like to produce toner particles. In the emulsion aggregation method, toner particles are produced through, for example, a dispersion process in which a fine particle dispersion liquid made of the constituent materials of toner particles is prepared, an aggregation process in which fine particles made of the constituent materials of toner particles are aggregated and the particle size is controlled until the particle size reaches that of toner particles, a fusion process in which the resin contained in the resulting aggregated particles is fused, a spheronization process in which the particles are melted by heating or the like and the surface shape of the toner is controlled, a subsequent cooling process, a metal removal process in which the resulting toner is filtered and excess polyvalent metal ions are removed, a filtration and washing process in which the toner is washed with ion-exchanged water or the like, and a process in which the washed toner particles are dehydrated and dried.

[0067] <Step of preparing a resin particle dispersion (dispersion step)> The resin particle dispersion can be prepared by a known method, but is not limited to these methods. Examples of known methods include emulsion polymerization, self-emulsification, phase inversion emulsification in which a resin is emulsified by adding an aqueous medium to a resin solution dissolved in an organic solvent, and forced emulsification in which a resin is forcibly emulsified by high-temperature treatment in an aqueous medium without using an organic solvent. Specifically, the binder resin is dissolved in an organic solvent capable of dissolving the binder resin, and a surfactant and a basic compound are added. In this case, if the binder resin is a crystalline resin having a melting point, it can be dissolved by heating it to a temperature above the melting point. Next, while stirring with a homogenizer or the like, an aqueous medium is slowly added to precipitate the resin fine particles, and the solvent is then removed by heating or reducing the pressure to prepare an aqueous dispersion of the resin fine particles. The organic solvent used to dissolve the binder resin is not particularly limited as long as it can dissolve the binder resin. However, it is preferable to use an organic solvent that forms a homogeneous phase with water, such as toluene, from the viewpoint of suppressing the generation of coarse powder.

[0068] The surfactant used during the emulsification is not particularly limited, but examples thereof include anionic surfactants such as sulfate salts, sulfonates, carboxylates, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. These surfactants may be used alone or in combination. Among these, at least one selected from the group consisting of sodium tetradecylbenzenesulfonate and sodium dodecylbenzenesulfonate is preferred, with sodium dodecylbenzenesulfonate being more preferred.

[0069] Examples of the basic compound used in the dispersion step include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as ammonia, triethylamine, trimethylamine, dimethylaminoethanol, and diethylaminoethanol. The basic compound may be used alone or in combination of two or more. The 50% particle diameter (D50) of the binder resin particles in the binder resin particle dispersion is preferably 0.05 μm to 1.0 μm, more preferably 0.05 μm to 0.4 μm. By adjusting the 50% particle diameter (D50) of the volume distribution to fall within the above range, it becomes easy to obtain toner particles with a volume average particle diameter of 3 μm to 10 μm, which is an appropriate size for toner particles. The 50% particle size (D50) based on volume distribution is measured using a dynamic light scattering particle size distribution analyzer Nanotrac UPA-EX150 (manufactured by Nikkiso).

[0070] <Colorant particle dispersion> In the emulsion aggregation method, a colorant particle dispersion may be used as needed. The colorant particle dispersion can be prepared by the following known methods, but is not limited to these methods. The colorant, aqueous medium, and dispersant can be mixed using a known mixer such as a stirrer, emulsifier, or disperser to prepare the dispersion. Known dispersants such as surfactants and polymer dispersants can be used as the dispersant.

[0071] Both surfactants and polymer dispersants can be removed in the washing step described below, but surfactants are preferred from the viewpoint of washing efficiency. Examples of surfactants include anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, and soap-based surfactants; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, nonionic surfactants or anionic surfactants are preferred. A nonionic surfactant and an anionic surfactant may also be used in combination. The surfactants may be used alone or in combination of two or more. The concentration of the surfactant in the aqueous medium is preferably 0.5% by mass to 5% by mass. The content of the colorant particles in the colorant particle dispersion is not particularly limited, but is preferably 1% by mass to 30% by mass relative to the total mass of the colorant particle dispersion.

[0072] From the viewpoint of dispersibility of the colorant in the final toner, the particle size of the colorant particles dispersed in the colorant particle dispersion liquid is preferably 0.5 μm or less in terms of the 50% particle size (D50) based on volume distribution, and for the same reason, preferably 2 μm or less in terms of the 90% particle size (D90) based on volume distribution. The particle size of the dispersed colorant particles in the colorant particle dispersion is measured using a dynamic light scattering particle size distribution analyzer (Nanotrac UPA-EX150, manufactured by Nikkiso Co., Ltd.).

[0073] Known mixers such as stirrers, emulsifiers, and dispersers used when dispersing a colorant in an aqueous medium include ultrasonic homogenizers, jet mills, pressure homogenizers, colloid mills, ball mills, sand mills, and paint shakers. These may be used alone or in combination.

[0074] <Release agent particle dispersion> In the emulsion aggregation method, a dispersion of releasing agent particles may be used as needed. The dispersion of releasing agent particles can be prepared by the following known methods, but is not limited to these methods. A release agent microparticle dispersion can be prepared by adding the release agent to an aqueous medium containing a surfactant, heating the mixture to above the melting point of the release agent, dispersing the mixture into particles using a homogenizer with strong shearing capabilities (such as the Clearmix W Motion manufactured by M Technique) or a pressure discharge type disperser (such as the Gaulin Homogenizer manufactured by Gaulin), and then cooling the mixture to below the melting point of the release agent.

[0075] The particle size of the release agent particles dispersed in the release agent particle dispersion liquid is preferably 0.03 μm to 1.0 μm, more preferably 0.1 μm to 0.5 μm, in terms of the 50% particle size (D50) based on volume distribution. It is also preferable that no coarse particles of 1 μm or more exist. When the dispersed particle size of the release agent fine particle dispersion is within the above range, the release agent can be finely dispersed and present in the toner, and the exudation effect during fixing can be maximized, making it possible to obtain good separability. The particle size of the release agent particles dispersed in the release agent particle dispersion is measured using a dynamic light scattering particle size distribution analyzer (Nanotrac UPA-EX150, manufactured by Nikkiso Co., Ltd.).

[0076] <Mixing process> The toner manufacturing method may include a mixing step. In the mixing step, a resin particle dispersion liquid and, if necessary, at least one of a release agent particle dispersion and a colorant particle dispersion, to prepare a mixed liquid. The mixing step can be carried out using a known mixing device such as a homogenizer or a mixer.

[0077] <Step of forming aggregate particles (aggregation step)> In the aggregating step, the binder resin microparticles contained in the binder resin microparticle dispersion liquid prepared in the mixing step are aggregated to form aggregates having a target particle size. At this time, an aggregating agent is added and mixed, and at least one of heat and mechanical power is appropriately applied as needed to form aggregates in which the resin microparticles and, as needed, at least one of the release agent microparticles and the colorant microparticles are aggregated.

[0078] Examples of the flocculant include organic flocculants such as quaternary salt cationic surfactants and polyethyleneimine; inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate; inorganic ammonium salts such as ammonium sulfate, ammonium chloride, and ammonium nitrate; and inorganic flocculants such as divalent or higher metal complexes. It is also possible to add an acid to lower the pH and cause soft flocculation, and examples of such acids include sulfuric acid and nitric acid.

[0079] The aggregating agent may be added in the form of either a dry powder or an aqueous solution dissolved in an aqueous medium, but is preferably added in the form of an aqueous solution to induce uniform aggregation. The addition and mixing of the aggregating agent is preferably carried out at a temperature below the glass transition temperature or melting point of the resin contained in the mixed liquid. By carrying out mixing under these temperature conditions, aggregation proceeds relatively uniformly. The aggregating agent can be mixed into the mixed liquid using a known mixing device such as a homogenizer or a mixer. The aggregation process is a process of forming aggregates of the size of toner particles in an aqueous medium. The volume average particle size of the aggregates produced in the aggregation step is preferably 3 μm to 10 μm. The volume average particle size can be measured using a particle size distribution analyzer (Coulter Multisizer III, manufactured by Coulter) by the Coulter method.

[0080] <Step of Obtaining a Dispersion Containing Toner Particles (Fusion Step)> In the fusion step, the aggregates obtained in the aggregation step are fused by heating. Specifically, for example, aggregation is first stopped in a dispersion containing the aggregates under stirring in the same manner as in the aggregation step. The aggregation is stopped by adding an aggregation stopper, such as a base capable of adjusting the pH, a chelating compound, or an inorganic salt compound such as sodium chloride. After the dispersion state of the aggregated particles in the dispersion liquid becomes stable due to the action of the aggregation terminator, the dispersion is heated to a temperature equal to or higher than the glass transition temperature or melting point of the binder resin to fuse the aggregated particles and adjust the particle size to the desired size. The 50% particle size (D50) on a volume basis of the toner particles is preferably 3 μm to 10 μm. The heating temperature is not particularly limited, but is preferably 40 to 60°C, for example.

[0081] <Step for obtaining the desired toner surface shape (spheronization step)> The toner manufacturing method preferably includes a spheronization step in which the aggregates are heated at a higher temperature during or after the fusion step. The spheronization step is a step in which the toner particles are maintained at a desired temperature until they achieve a desired circularity or surface shape. Specific temperatures in the spheronization step are, for example, 90°C or higher, preferably 92°C or higher, and preferably 95°C or lower. The heating time in the spheronization step can be, for example, 3 hours or more, 5 hours or more, or 8 hours or more.

[0082] <Cooling process> In the toner manufacturing method, after the spheronization step, the aggregates are cooled at a cooling rate of 0.1°C / second or more. It is preferable to have a cooling step in which the dispersion liquid containing the toner particles obtained in the spheronization step is cooled to a temperature lower than the crystallization temperature or glass transition temperature of the binder resin by controlling the cooling rate. By undergoing the cooling step, the formation of irregularities on the toner particle surface due to volume changes such as expansion or contraction of the materials in the toner particles can be suppressed. A specific cooling rate is 0.1°C / sec or higher, preferably 0.5°C / sec or higher, more preferably 2°C / sec or higher, and even more preferably 4°C / sec or higher.

[0083] <Post-processing process> In the toner production method, post-treatment steps such as a washing step, a solid-liquid separation step, and a drying step may be further carried out, and by carrying out the post-treatment steps, toner particles in a dried state can be obtained.

[0084] <External addition process> The toner manufacturing method may include an external addition step. In the external addition step, rutile-anatase titania particles and hydrotalcite particles are externally added to the obtained toner particles. If necessary, other conventionally known fine particles may be used in combination. The amount of other fine particles added may be 0.1 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of toner particles, but from the viewpoint of achieving both durability and resistance to component contamination of the toner, it is preferably 0.1 parts by mass or more and 3.0 parts by mass or less, and more preferably 0.2 parts by mass or more and 2.0 parts by mass or less.

[0085] Next, the measurement methods for each physical property will be described.

[0086] <Method for separating rutile-anatase titania particles and hydrotalcite particles from external additives contained in toner> The toner is ultrasonically dispersed in methanol to separate the rutile-anatase titania particles and other external additives such as hydrotalcite particles from the toner particles, and the mixture is left to stand for 24 hours. The settled toner particles are separated from the rutile-anatase titania particles and other external additives dispersed in the supernatant, and the resulting mixture is thoroughly dried to isolate the toner particles. The supernatant can also be centrifuged to isolate the rutile-anatase titania particles and hydrotalcite particles.

[0087] <Method for measuring the rutile / anatase ratio> The rutile / anatase ratio of rutile-anatase titania particles was measured using a powder X-ray diffractometer "SmartLab" (Rigaku Corporation, horizontal sample-mounted high-power X-ray diffractometer). Calculations from the obtained peaks were performed using the analysis software "PDXL2 (version 2.2.2.0)" that came with the instrument. Titania particles isolated from a toner are used as a measurement sample, and measurements are made according to the following procedure: In the following examples and comparative examples, manufactured titania particles are measured.

[0088] (Sample preparation) Titania particles are uniformly placed in a 0.5 mm diameter Boro-Silicate capillary (manufactured by W. Muller) to prepare a measurement sample.

[0089] (Measurement conditions) ·Tube:Cu ·Optical system: CBO-E Sample stage: Capillary sample stage Detector: D / tex Ultra250 detector Voltage: 45kV ·Current: 200mA ·Starting angle: 10° End angle: 60° Sampling width: 0.02° Speed ​​measurement time setting value: 10 IS:1mm RS1: 20mm RS2: 20mm Attenuator: Open Capillary rotation speed setting: 100 The other conditions are the default settings of the instrument. Measurement of the measurement sample is carried out using the above conditions.

[0090] (analysis) First, the obtained peaks are separated using the software "PDXL2" that comes with the instrument. Peak separation is performed by performing optimization using the "divided Voigt function" that can be selected in PDXL, and the obtained peak intensities are used. Intensity of the strongest interference line (plane index 110) originating from rutile-type TiO2 to determine the rutile / anatase ratio. R and the intensity I of the strongest interference line (plane index 101) originating from anatase TiO2. A The anatase content and rutile content are calculated from the above using the following formulas (2) and (3), and the rutile / anatase ratio is calculated using formula (4). Anatase content (%) = 100 / (1 + 1.265 × (I R / I A )) (2) Rutile content (%) = 100 - Anatase content (%) (3) Rutile / anatase ratio = rutile content / anatase content (4)

[0091] <Method for measuring the number-average major axis diameter L1 and number-average minor axis diameter L2 of primary particles of rutile-anatase titania particles> The number average value L1 of the major axis diameter of the primary particles of the rutile-anatase-type titania particles and the number average value L2 of the minor axis diameter of the primary particles of the rutile-anatase-type titania particles are measured using a transmission electron microscope "JEM-2800" (JEOL Ltd.). Toner containing externally added rutile-anatase titania particles (hereinafter simply referred to as titania particles) is observed, and the major axis diameter of the primary particles of 100 titania particles randomly selected to avoid arbitrariness is measured in a field of view magnified up to 200,000 times to obtain the number average value L1. The minor axis of the titania particles, which is perpendicular to the major axis diameter, is also measured at the same time to obtain the number average value L2.

[0092] The observation magnification is adjusted appropriately depending on the size of the titania particles. The external additive is confirmed to be rutile-anatase titania particles by STEM-EDS measurement. The measurement conditions are as follows. JEM2800 transmission electron microscope: accelerating voltage 200 kV EDS detector: JED-2300T (JEOL, element area 100 mm 2 ) EDS analyzer: Noran System 7 (Thermo Fisher Scientific) was used. X-ray storage rate: 10,000~15,000cps Dead time: Adjust the electron dose so that it is 20-30%, and perform EDS analysis (100 times accumulation or measurement time 5 minutes). When 80% or more of the titania particles are spindle-shaped by STEM-EDS measurement, the external additive is determined to be rutile-anatase titania particles.

[0093] <Method for measuring the number-average major axis diameter L3 of primary particles of hydrotalcite particles> The number average value L3 of the major axis diameter of the primary particles of hydrotalcite particles was measured using a transmission electron microscope. This is done using a microscope "JEM-2800" (JEOL Ltd.). The toner to which hydrotalcite particles have been externally added is observed, and the major axis diameter of the primary particles of 100 hydrotalcite particles randomly selected so as not to be arbitrary is measured in a field of view magnified up to 200,000 times, and the number average value L3 is calculated.

[0094] The observation magnification is adjusted appropriately depending on the size of the hydrotalcite particles. The external additive is confirmed to be hydrotalcite particles by STEM-EDS measurement. The measurement conditions are as follows. JEM2800 transmission electron microscope: accelerating voltage 200 kV EDS detector: JED-2300T (JEOL, element area 100 mm 2 ) EDS analyzer: Noran System 7 (Thermo Fisher Scientific) was used. X-ray storage rate: 10,000~15,000cps Dead time: The electron dose was adjusted to 20-30%, and EDS analysis was performed (100 times accumulation or 5 minutes measurement time).

[0095] <Method for measuring the content M1 of rutile-anatase titania particles and the content M2 of hydrotalcite particles in toner> The masses of the toner particles, rutile-anatase-type titania particles, and hydrotalcite particles isolated using the above-described method for separating rutile-anatase-type titania particles and hydrotalcite particles are measured. From the obtained masses, the content of the rutile-anatase-type titania particles per 100 parts by mass of the toner particles is calculated and designated M1 (parts by mass). Furthermore, from the obtained masses, the content of the hydrotalcite particles per 100 parts by mass of the toner particles is calculated and designated M2 (parts by mass).

[0096] <Method for measuring volume resistivity ρV of rutile-anatase titania particles> The volume resistivity ρV of rutile-anatase titania particles is measured as follows: A Keithley Instruments 6517 Electrometer / High Resistance System is used as the device. Electrodes with a diameter of 25 mm are connected, and titania particles are placed between the electrodes to a thickness of approximately 0.5 mm. The distance between the electrodes is measured with a load of approximately 2.0 N applied. A voltage of 1,000 V is applied to the titania particles for 1 minute, and the volume resistance value is measured, and the volume resistivity is calculated using the following formula (5). Volume resistivity (Ω cm)=R×L (5) R: Resistance value (Ω) L: Distance between electrodes (cm)

[0097] <Method for measuring weight average particle size (D4) of toner particles> The weight-average particle size (D4) of the toner particles is calculated as follows. The measurement device used is a precision particle size distribution analyzer, "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.), equipped with a 100 μm aperture tube and employing the narrow-pore electrical resistance method. The measurement conditions and measurement data are analyzed using the accompanying dedicated software, "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.). Measurements are performed using an effective number of 25,000 measurement channels. The electrolyte solution used for the measurements is prepared by dissolving special-grade sodium chloride in ion-exchange water to a concentration of approximately 1% by mass; for example, "ISOTON II" (manufactured by Beckman Coulter, Inc.).

[0098] Before measurement and analysis, the dedicated software was set as follows: On the "Change Standard Measurement Method (SOM)" screen of the dedicated software, the total count number in the control mode was set to 50,000 particles, the number of measurements was set to 1, and the Kd value was set to "Standard particle 10.0 μm." Set the values ​​obtained using a Beckman Coulter analyzer. Press the "Threshold / Noise Level Measurement Button" to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement." In the "Pulse to particle size conversion settings" screen of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range from 2 μm to 60 μm.

[0099] The specific measurement method is as follows. (1) Pour approximately 200 ml of the electrolyte solution into a 250 ml round-bottom glass beaker made specifically for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture flush" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube. (2) Approximately 30 ml of the above-mentioned aqueous electrolyte solution is placed in a 100 ml flat-bottom glass beaker, and approximately 0.3 ml of a dilution of Contaminon N (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted approximately three times by mass with ion-exchanged water is added as a dispersant. (3) Prepare an ultrasonic disperser "Ultrasonic Dispension System Tetora150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W and equipped with two built-in oscillators with an oscillation frequency of 50 kHz and a phase difference of 180 degrees. 3.3 L of ion-exchanged water is placed in the ultrasonic disperser's water tank, and approximately 2 ml of Contaminon N is added to the water tank. (4) Place the beaker from (2) into the beaker fixing hole of the ultrasonic disperser, and operate the ultrasonic disperser. Then, adjust the height of the beaker so that the resonance state of the electrolyte solution surface in the beaker is maximized. (5) While the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, approximately 10 mg of toner is added little by little to the electrolyte solution and dispersed. The ultrasonic dispersion process is then continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be between 10°C and 40°C. (6) Using a pipette, add the electrolyte solution (5) containing the dispersed toner to the round-bottom beaker (1) placed in the sample stand, and adjust the measurement concentration to approximately 5%. Then, measure the particle count until it reaches 50,000 particles. (7) The measurement data is analyzed using the dedicated software provided with the device to calculate the weight-average particle size (D4). Note that when the dedicated software is set to Graph / Volume %, the "Average diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" screen is the weight-average particle size (D4).

[0100] <Method for isolating binder resin from toner particles> Method for isolating binder resin from toner particles 100 mg of the toner particles isolated using the method described above was dissolved in 3 ml of chloroform. Next, the chloroform-insoluble material was removed by suction filtration using a syringe equipped with a sample processing filter (pore size 0.2 μm to 0.5 μm, such as a Myshoridisk H-25-2 (Tosoh Corporation)). The chloroform-soluble material was introduced into a preparative HPLC (apparatus: Japan Analytical Industry Co., Ltd. LC-9130 NEXT preparative column [60 cm], exclusion limits: 20,000 and 70,000, two columns connected), and the chloroform eluent was pumped. Once a peak was confirmed in the resulting chromatographic display, the retention time corresponding to a molecular weight of 2,000 or greater using a monodisperse polystyrene standard sample was collected. The resulting fraction solution was dried and solidified to separate it from the release agent and collect the binder resin.

[0101] <Composition analysis of polyester resin A> The chloroform-soluble portion of the separated binder resin is used as the sample. The sample is adjusted with chloroform so that the toner particle concentration is 0.1% by mass, and the solution is filtered through a 0.45 μm PTFE filter before being used for measurement. The gradient polymer LC measurement conditions are as follows: . Equipment: UlTIMATE3000 (Thermo Fisher Scientific) Mobile phase: A chloroform (HPLC), B acetonitrile (HPLC) Gradient: 2 min (A / B = 0 / 100) → 25 min (A / B = 100 / 0) (Note: The gradient of the mobile phase change should be linear.) Flow rate: 1.0mL / min Injection: 0.1% by mass x 20μL Column: Tosoh TSKgel ODS (4.6mmφ x 150mm x 5μm) Column temperature: 40℃ Detector: Corona Charged Aerosol Detector (Corona-CAD) (Thermo Fisher Scientific)

[0102] Polyester resin A is separated at a separation time corresponding to polyester resin A. In the separation, a required amount of each chloroform / acetonitrile solution is collected, dried, and concentrated to obtain a sample of polyester resin A. The content of polyester resin A in the binder resin is calculated from the amount of polyester resin A obtained and the amount of separated binder resin.

[0103] Using a sample of the polyester resin component A, the composition ratio and mass ratio are measured by nuclear magnetic resonance spectroscopy (NMR) as follows. 1 mL of deuterated chloroform is added to 20 mg of a sample of polyester resin component A, and the proton NMR spectrum of the dissolved resin is measured. From the obtained NMR spectrum, the molar ratio and mass ratio of each monomer can be calculated, and the content ratio of each monomer unit can be determined. For nuclear magnetic resonance spectroscopy (NMR), the following devices and measurement conditions can be used. NMR device: RESONANCE ECX500 manufactured by JEOL Ltd. Observed nucleus: proton Measurement mode: single pulse

[0104] <Method for quantifying the content of monomer units corresponding to isophthalic acid in polyester resin A by NMR measurement> · Identification of components of polyester resin A and measurement of molar ratio and mass ratio by nuclear magnetic resonance spectroscopy (NMR) The obtained polyester resin A; 20 mg is added with 1 mL of deuterated chloroform and dissolved, and the NMR spectrum of the protons of the dissolved polyester resin A is measured. From the obtained NMR spectrum, the molar ratio and mass ratio of each monomer are calculated by taking the smallest unit sandwiched by ester bonds as the structure derived from the monomer. For example, the composition ratio and mass ratio can be calculated based on the following peaks (chemical shift value, number of protons). Unit derived from isophthalic acid: 7.5 ppm (1), 8.2 ppm (2), 8.7 ppm (1) Unit derived from terephthalic acid: 8.1 ppm (4) Unit derived from ethylene oxide adduct of bisphenol A: 1.6 ppm (6), 4.3 ppm (4), 4.7 ppm (4), 6.8 ppm (4), 7.1 ppm (4) Unit derived from propylene oxide adduct of bisphenol A: 1.5 ppm (6), 1.6 ppm (6), 4.1 ppm (4), 5.5 ppm (2), 6.8 ppm (4), 7.1 ppm (4) NMR device: JEOL RESONANCE ECX500 Observed nucleus: proton Measurement mode: single pulse Reference peak: TMS

[0105] By this NMR analysis, the content (mol%) of the monomer unit corresponding to isophthalic acid with respect to all monomer units corresponding to polyvalent carboxylic acids is determined. When the content ratio is expressed in mass % or mass parts, it is calculated in the same manner as above. [Example]

[0106] The toner of the present disclosure will be described in detail below using examples and comparative examples, but the present disclosure is not limited to these examples. In the following description of the examples, "parts" refers to parts by mass unless otherwise specified.

[0107] <Production Example of Polyester Resin A1> Bisphenol A ethylene oxide 2 mole adduct 25 mol parts Bisphenol A propylene oxide 2 mole adduct 27 mole parts Isophthalic acid 60 mol parts Terephthalic acid 40 mol parts The above monomers were charged into a flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and distillation column, and the temperature was raised to 190°C over 1 hour. It was confirmed that the reaction system was uniformly stirred. 1.0 part of tin distearate was added to 100 parts of these monomers. The temperature was then raised from 190°C to 245°C over 5 hours while distilling off the generated water, and the dehydration condensation reaction was carried out at 245°C for an additional 2 hours. As a result, polyester resin A1 having a glass transition temperature of 60.1° C., an acid value of 10 mgKOH / g, a hydroxyl value of 25 mgKOH / g, Mn of 4800, and Mw / Mn of 6.7 was obtained.

[0108] <Production Examples of Polyester Resins A2 to A3> Polyester resins A2 to A3 were obtained in the same manner as in the production example for polyester resin A1, except that the amounts of isophthalic acid and terephthalic acid were changed as shown in Table 1. [Table 1] In the table, "Total Acids" indicates the total polycarboxylic acids used as raw materials for polyester resin A, and "Uiso / Total Acids" indicates the content of monomer units corresponding to isophthalic acid based on the total monomer units corresponding to polycarboxylic acids in polyester resin A.

[0109] <Production of Polyester Resin B> 100 parts by mass of a mixture of 430 mol parts of terephthalic acid, 1.3 mol parts of trimellitic acid, 30 mol parts of a 2-mol propylene oxide adduct of bisphenol A, 18.0 mol parts of ethylene glycol, and 2.0 mol parts of isosorbide, along with 0.55 parts by mass of tin di(2-ethylhexanoate) as a catalyst, were placed in a 6-liter four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple. The mixture was then reacted at 200°C for 6 hours under a nitrogen atmosphere. 80 mol parts of trimellitic anhydride were then added at 210°C, and the reaction was continued under a reduced pressure of 40 kPa until the weight-average molecular weight (Mw) reached 12,000. The resulting polyester resin was designated polyester resin B. The alicyclic structure of polyester resin B was a monomer unit represented by the following formula (A): [ka]

[0110] <Production example of charge control resin E> 9.2 g of the polymerizable monomer shown in the following formula (B) and 60.1 g of styrene were dissolved in 42.0 ml of dimethylformamide (DMF). The mixture was stirred for 1 hour while bubbling with nitrogen and then heated to 110°C. A mixture of 2.1 g of tert-butylperoxyisopropyl monocarbonate (manufactured by NOF Corporation, product name Perbutyl I) as an initiator and 42 ml of toluene was added dropwise to the reaction solution. The reaction was continued for another 4 hours at 110°C. The reaction solution was then cooled and added dropwise to 1 L of methanol to obtain a precipitate. The resulting precipitate was dissolved in 120 ml of tetrahydrofuran (THF) and then added dropwise to 1.80 L of methanol to obtain a white precipitate. The resulting precipitate was then filtered and dried under reduced pressure at 90°C to obtain charge control resin E. [ka]

[0111] <Preparation example of resin particle dispersion 1> Polyester resin A1: 100.0 parts Polyester resin B: 2.0 parts Charge control resin E: 0.2 parts Ion-exchanged water: 350 parts The above materials were placed in a stainless steel container and melted by heating to 95°C in a hot bath. Then, while thoroughly stirring at 7800 rpm using a homogenizer (IKA Ultra Turrax T50), 0.1 mol / L sodium bicarbonate was added to adjust the pH of the mixture to above 7.0. Thereafter, a mixed solution of 3 parts of sodium dodecylbenzenesulfonate as a surfactant and 300 parts of ion-exchanged water was gradually added dropwise to emulsify and disperse the mixture, thereby obtaining a resin particle dispersion. The dispersion was cooled to room temperature, and ion-exchanged water was added to obtain resin particle dispersion 1 having a solids concentration of 12.5 mass% and a volume-based median diameter of 0.2 μm.

[0112] <Preparation Examples of Resin Particle Dispersions 2 to 6> Resin particle dispersions 2 to 6 were obtained in the same manner as in the preparation example of resin particle dispersion 1, except that the types of polyester resin A and surfactant, the number of parts of polyester resin B, and the number of parts of charge control resin E were changed as shown in Table 2. [Table 2]

[0113] <Preparation example of resin particle dispersion liquid 7> A solution was prepared by mixing and dissolving 78.0 parts of styrene, 20.7 parts of butyl acrylate, 2.0 parts of polyester resin B, and 0.2 parts of charge control resin E. To this solution was added an aqueous solution of 1.5 parts of an ionic surfactant (trade name: Neogen RK, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) in 150.0 parts of ion-exchanged water, and the mixture was dispersed. While slowly stirring for another 10 minutes, an aqueous solution of 0.3 parts potassium persulfate dissolved in 10.0 parts ion-exchanged water was added. After nitrogen substitution, emulsion polymerization was carried out at 70°C for 6 hours. After polymerization was completed, the reaction solution was cooled to room temperature, and ion-exchanged water was added to obtain resin particle dispersion 7 with a solids concentration of 12.5% ​​by mass and a volume-based median diameter of 0.2 μm.

[0114] <Preparation example of wax dispersion 1> 100 parts of behenyl behenate (melting point: 75°C) and 15 parts of NEOGEN RK were mixed with 385 parts of ion-exchanged water, and the mixture was dispersed for about 1 hour using a wet jet mill JN100 (manufactured by Joko Co., Ltd.) to obtain wax dispersion 1. The concentration of wax dispersion 1 was 20% by mass.

[0115] <Preparation example of wax dispersion 2> 100 parts of dibehenyl sebacate (melting point: 75°C) and 15 parts of Neogen RK were mixed with 385 parts of ion-exchanged water, and the mixture was dispersed for about 1 hour using a wet jet mill JN100 (manufactured by Joko Co., Ltd.) to obtain wax dispersion 2. The concentration of wax dispersion 2 was 20% by mass.

[0116] <Preparation example of wax dispersion 3> 100 parts of hydrocarbon wax (melting point: 75°C) and 15 parts of NEOGEN RK were mixed with 385 parts of ion-exchanged water, and dispersed for about 1 hour using a wet jet mill JN100 (manufactured by Joko Corporation) to obtain wax dispersion 3. The concentration of wax dispersion 3 was 20% by mass.

[0117] <Preparation example of colorant dispersion 1> 100 parts of carbon black and 15 parts of Neogen RK were mixed with 885 parts of ion-exchanged water as colorants, and dispersed for about 1 hour using a wet jet mill JN100 to obtain colorant dispersion 1. Got it.

[0118] <Production Example of Toner Particle 1> A mixture of 1:265 resin particle dispersion, 1:20 wax dispersion, and 1:20 colorant dispersion was dispersed using a homogenizer (IKA Ultra Turrax T50). The temperature inside the container was adjusted to 30°C while stirring, and a 1 mol / L aqueous sodium hydroxide solution was added to adjust the pH of the dispersion to 8.0. To the resulting dispersion, an aqueous solution of 0.23 parts of aluminum chloride dissolved in 10 parts of ion-exchanged water as a flocculant was added over 10 minutes while stirring at 30°C. After leaving it for 3 minutes, the temperature was raised to 50°C to generate associated particles. In this state, the aggregates were measured using a Coulter Counter Multisizer 3 (registered trademark, manufactured by Beckman Coulter, Inc.). The particle size of the composite particles was measured, and when the weight average particle size reached 6.0 μm, 0.9 parts of sodium chloride and 5.0 parts of NEOGEN RK were added to stop particle growth.

[0119] The resulting dispersion was adjusted to pH 9.0 by adding 1 mol / L aqueous sodium hydroxide solution. The dispersion was then heated to 95°C to spheronize the aggregated particles. After the average circularity reached 0.980, the temperature was lowered to room temperature, yielding toner particle dispersion 1. Hydrochloric acid was added to the obtained toner particle dispersion 1 to adjust the pH to 1.5. After stirring for 1 hour, the mixture was subjected to solid-liquid separation using a pressure filter to obtain a toner cake. This was reslurried with ion-exchanged water to form a dispersion again, and then subjected to solid-liquid separation using a pressure filter. The reslurrying and solid-liquid separation were repeated until the electrical conductivity of the filtrate reached 5.0 μS / cm or less, after which solid-liquid separation was finally performed to obtain a toner cake. The obtained toner cake was dried and further classified using a classifier to obtain toner particles 1.

[0120] <Preparation Examples of Toner Particles 2 to 9> Toner particles 2 to 9 were produced in the same manner as toner particles 1, except that the types of resin particle dispersion and wax particle dispersion used were changed as shown in Table 3. [Table 3]

[0121] <Production Example of Rutile Anatase Titania Particles 1> The starting material was ilmenite ore containing 50% by mass of TiO2 equivalent. This material was dried at 150°C for 2 hours, and then sulfuric acid was added and dissolved to obtain an aqueous solution of TiOSO2. Sodium carbonate was added to this solution to adjust the pH to 9.0, and the solution was then filtered to obtain a white precipitate. Pure water was added to this white precipitate, and the mixture was heated at 90°C for 2.5 hours to carry out hydrolysis. After that, filtration and washing with water were repeated to obtain anatase titanium dioxide. The resulting anatase-type titanium oxide was sintered at a high temperature of 900°C to obtain rutile-anatase-type titanium oxide. The treatment time was adjusted so that the rutile / anatase ratio was 25 / 75. The resulting rutile-anatase-type titanium oxide was then crushed in a jet mill to obtain rutile-anatase-type titania particles. These titania particles were dispersed in ethanol, and 10 parts by mass (solids) of isobutyltrimethoxysilane as a hydrophobizing agent was added dropwise to 100 parts by mass of the titania particles while stirring thoroughly to prevent particle coalescence, and the mixture was reacted to perform a hydrophobizing treatment. While stirring thoroughly, a 5N aqueous solution of sodium hydroxide was added to adjust the pH of the slurry to 6.5. The slurry was filtered, dried, and then heat-treated at 170°C for 2 hours. The slurry was then repeatedly crushed using a jet mill until no titanium oxide aggregates remained, yielding rutile-anatase titania particles 1.

[0122] <Production Examples of Rutile Anatase Titania Particles 2-23> The high-temperature heating temperature and high-temperature heating time were adjusted so that the rutile / anatase ratio was the value shown in Table 4. Rutile-anatase type particles 2 to 23 were obtained in the same manner as in the production example for rutile-anatase type particle 1, except that the operating conditions of the jet mill were adjusted so that the values ​​of L1 and L2 were as shown in Table 4, the type of hydrophobizing agent was as shown in Table 4, and the number of parts of the hydrophobizing agent was appropriately adjusted so that the volume resistivity was as shown in Table 4. The physical properties of the obtained rutile-anatase type titania particles 2 to 23 are shown in Table 4. For rutile-anatase type titania particle 22, no hydrophobizing agent was added. [Table 4] In the table, titania particles refer to rutile-anatase type titania particles, and R / A indicates the rutile / anatase ratio. For example, "1.E+08" means "1 x 10 8 " represents.

[0123] <Production Example of Rutile-Type Titania Particles 1> The starting material was ilmenite ore containing 50% by mass of TiO2 equivalent. This material was dried at 150°C for 2 hours, and then sulfuric acid was added and dissolved to obtain an aqueous solution of TiOSO2. Sodium carbonate was added to this solution to adjust the pH to 9.0, and the solution was then filtered to obtain a white precipitate. Pure water was added to this white precipitate, and the mixture was heated at 90°C for 2.5 hours to carry out hydrolysis. After that, filtration and washing with water were repeated to obtain anatase titanium dioxide. The resulting anatase-type titanium oxide was sintered at a high temperature of 1100°C to obtain rutile-type titanium oxide. The treatment time was adjusted to obtain rutile-type titanium oxide. The resulting rutile-type titanium oxide was then crushed using a jet mill to obtain rutile-type titania particles. The rutile-type titania particles were dispersed in ethanol, and 10 parts by mass (solid content) of isobutyltrimethoxysilane as a hydrophobizing agent was added dropwise to 100 parts by mass of the rutile-type titania particles while stirring thoroughly to prevent particle coalescence, and the mixture was reacted to perform a hydrophobizing treatment. While stirring thoroughly, a 5N aqueous solution of sodium hydroxide was added to adjust the pH of the slurry to 6.5. After filtering and drying, the slurry was heat-treated at 170°C for 2 hours. After that, the slurry was repeatedly crushed using a jet mill until no agglomerates of rutile titanium oxide remained. Rutile-type titania particles 1 were obtained.

[0124] <Production Example of Anatase-Type Titania Particles 1> The starting material was ilmenite ore containing 50% by mass of TiO2 equivalent. This material was dried at 150°C for 2 hours, and then sulfuric acid was added and dissolved to obtain an aqueous solution of TiOSO2. Sodium carbonate was added to this solution to adjust the pH to 9.0, and the solution was then filtered to obtain a white precipitate. Pure water was added to this white precipitate, and the mixture was heated at 90°C for 2.5 hours to carry out hydrolysis. After that, filtration and washing with water were repeated to obtain anatase titanium oxide. The resulting anatase-type titanium oxide was crushed in a jet mill to obtain anatase-type titania particles. These anatase-type titania particles were dispersed in ethanol, and 10 parts by mass of isobutyltrimethoxysilane (solid content) as a hydrophobizing agent was added dropwise to 100 parts by mass of the anatase-type titania particles while stirring thoroughly to prevent particle coalescence, and the reaction was allowed to proceed to hydrophobize the particles. While stirring thoroughly, an aqueous sodium bicarbonate solution was added to adjust the pH of the slurry to 6.5. The slurry was filtered, dried, and then heat-treated at 170°C for 2 hours. The slurry was then repeatedly crushed using a jet mill until no aggregates of anatase-type titanium oxide remained, yielding anatase-type titania particles 1.

[0125] <Production example of hydrotalcite particles 1> A mixed aqueous solution of 1.03 mol / L magnesium chloride and 0.239 mol / L aluminum sulfate (liquid A), a 0.753 mol / L sodium carbonate aqueous solution (liquid B), and a 3.39 mol / L sodium hydroxide aqueous solution (liquid C) were prepared. Next, liquids A, B, and C were poured into a reaction vessel using a metering pump at a flow rate such that the volume ratio of liquid A to liquid B was 4.5:1. The pH value of the reaction solution was maintained in the range of 9.3 to 9.6 using liquid C, and the reaction temperature was 40°C to produce a precipitate. After filtration and washing, the precipitate was re-emulsified in ion-exchanged water to obtain a raw material hydrotalcite slurry. The hydrotalcite concentration in the obtained hydrotalcite slurry was 5.6% by mass. The mixture was then filtered through a membrane filter with a pore size of 0.5 μm and washed with ion-exchanged water. The resulting hydrotalcite was vacuum dried overnight at 40° C. and then crushed to the desired particle size. The physical properties of the resulting hydrotalcite particles 1 are shown in Table 5.

[0126] <Production example of hydrotalcite particles 2> A mixed aqueous solution of 1.03 mol / L magnesium chloride and 0.239 mol / L aluminum sulfate (liquid A), a 0.753 mol / L sodium carbonate aqueous solution (liquid B), and a 3.39 mol / L sodium hydroxide aqueous solution (liquid C) were prepared. Next, liquids A, B, and C were poured into the reaction vessel using a metering pump at a flow rate such that the volume ratio of liquid A to liquid B was 4.5:1. The pH value of the reaction solution was maintained in the range of 9.3 to 9.6 using liquid C, and the reaction temperature was 40°C to produce a precipitate. After filtration and washing, the precipitate was re-emulsified in ion-exchanged water to obtain a raw material hydrotalcite slurry. The hydrotalcite concentration in the obtained hydrotalcite slurry was 5.6% by mass. The obtained hydrotalcite slurry was dried under vacuum at 40°C overnight. NaF was dissolved in ion-exchanged water to a concentration of 100 mg / L, and the pH was adjusted to 7.0 using 1 mol / L HCl or 1 mol / L NaOH. The dried hydrotalcite was added to the solution to a concentration of 0.1% (w / v%). The mixture was stirred at a constant speed using a magnetic stirrer for 48 hours to prevent settling. The mixture was then filtered through a membrane filter with a pore size of 0.5 μm and washed with ion-exchanged water. The obtained hydrotalcite was dried under vacuum at 40°C overnight and then crushed to obtain hydrotalcite particles 2. The obtained fluorine-containing hydrotalcite particles were subjected to line analysis in a STEM-EDS mapping analysis, and as a result, fluorine was found to be present inside. The composition and physical properties of lucite particles 1 are shown in Table 5.

[0127] <Production Examples of Hydrotalcite Particles 3 to 8> Except for appropriately adjusting the concentration of liquid A: liquid B and the crushing strength, hydrotalcite particles 3 to 8 were obtained in the same manner as in the production example of hydrotalcite particles 1. The physical properties of the obtained hydrotalcite particles 3 to 8 are shown in Table 5. [Table 5]

[0128] <Toner 1 manufacturing example> External addition was carried out on toner particles 1. Using an FM mixer (FM10 manufactured by Nippon Coke and Engineering Co., Ltd.), 0.50 parts by mass of rutile-anatase type titania particles 1 and 0.25 parts by mass of hydrotalcite particles 1 were added to 100 parts by mass of toner particles 1, and then the mixture was mixed at 3000 rpm for 5 minutes. During this process, the temperature inside the tank was adjusted to 35°C after 5 minutes of mixing by controlling the flow rate and temperature of the cold water flowing through the cooling jacket. Thereafter, the toner was sieved through a mesh with 75 μm openings to obtain Toner 1. The physical properties are shown in Table 6.

[0129] <Toner 2-45 manufacturing example> Toners 2 to 45 were obtained in the same manner as in the production example of Toner 1, except that the type and number of rutile-anatase type titania particles and the type and number of hydrotalcite particles were changed as shown in Table 6. [Table 6] In the table, titania particles refer to rutile-anatase type titania particles.

[0130] <Toner 46 manufacturing example> Toner 46 was obtained in the same manner as in the production example of toner 1, except that the rutile-anatase type titania particles 1 in the production example of toner 1 were changed to rutile-type titania particles 1. The physical properties are shown in Table 7.

[0131] <Toner 47 manufacturing example> Toner 47 was obtained in the same manner as in the production example of toner 1, except that the rutile-anatase type titania particles 1 in the production example of toner 1 were changed to anatase type titania particles 1. The physical properties are shown in Table 7. [Table 7] In the table, M1, M2, L1 / L3, M1 / M2 and (log 10 The values ​​of (ρV) / (L1 / L2) are values ​​obtained by regarding the rutile titania particles 1 and the anatase titania particles 1 as rutile-anatase titania particles.

[0132] <Examples 1 to 43 and Comparative Examples 1 to 4> The following actual machine evaluation was carried out using Toners 1 to 47. The evaluation results are shown in Tables 8-1 and 8-2. For the evaluation, an HP LaserJet Enterprise M609dn was used with its process speed modified to 410 mm / sec. The evaluation paper was Vitality (Xerox, basis weight 75 g / cm 2 , letter size) was used.

[0133] <Ghosting evaluation in high temperature and humidity (HH) environments> The image output tester and the toner cartridge filled with the toner to be evaluated were left in a high-temperature, high-humidity environment of 32.5°C / 80%RH for at least one day, and then the image shown in Figure 1 was output using the image output tester. The image shown in Figure 1 allows for strict evaluation of ghosting characteristics. Specifically, when ghosting occurs, the density of the halftone area becomes distorted after the black band at the top is output. Ghosting was evaluated based on whether the disturbance could be visually confirmed. [Evaluation criteria] A: No trace of ghosts is visible. B: The shading corresponding to the black band is seen in the upper third of the image. C: The shading corresponding to the black band appears dark in the upper half of the image. D: Dark shading corresponding to the black bands is seen throughout the entire image. E: Shades corresponding to the black bands are clearly visible.

[0134] <Ghosting evaluation in low temperature and low humidity (LL) environment> The image output tester and the toner cartridge filled with the evaluation toner were left in a low-temperature, low-humidity environment of 10°C / 10% RH for at least one day, and then 10,000 test charts with a print ratio of 1% were printed using the image output tester. After printing 10,000 sheets, the image shown in Figure 1 was output. The image in Figure 1 allows for strict evaluation of ghosting characteristics. Specifically, when ghosting occurs, the density of the halftone area is disturbed after the black band at the top is output. Ghosting was evaluated based on whether the disturbance could be visually confirmed. [Evaluation criteria] A: No trace of ghosts is visible. B: A faint shade corresponding to the black band is seen in the upper third of the image. C: A faint shade corresponding to the black band is seen in the upper half of the image. D: Light shades corresponding to black bands are seen throughout the entire image. E: Shades corresponding to the black bands are clearly visible.

[0135] <Charging roller contamination evaluation> The image output tester and toner cartridge filled with the evaluation toner were left in a low-temperature, low-humidity environment of 10°C / 10% RH for at least one day, and then 10,000 test charts with a print ratio of 10% were printed using the image output tester. After printing 10,000 sheets, three halftone images with a print ratio of 23% were output. In this evaluation, if the charging roller is contaminated, the charging ability of the contaminated area decreases, causing black vertical stripes to appear when the halftone image is output. The number of vertical stripes that appeared on the three obtained halftone images was counted, and the charging roller contamination was evaluated using the following criteria. [Evaluation criteria] A: No streaks are visible. B: The width of the streaks is less than 0.5 mm, and the number of streaks is 1 or more and 3 or less. C: The width of the streaks is less than 0.5 mm, and the number of streaks is 4 or more and 6 or less. D: The width of the streaks is less than 0.5 mm, and the number of streaks is 7 or more and 9 or less. E: The number of streaks with a width of less than 0.5 mm is 10 or more, or streaks with a width of 0.5 mm or more have occurred.

[0136] <Photoreceptor contamination evaluation> The image reproduction tester and the toner cartridge filled with the toner to be evaluated were left in a high-temperature, high-humidity environment of 32.5°C / 80%RH for at least one day, and then 10,000 test charts with a print ratio of 15% were printed using the image reproduction tester. After printing 10,000 sheets, the toner coverage per unit area was 1.0 mg / cm. 2 A solid black image was outputted on the entire surface, and the surface of the photoreceptor and the solid black image were visually inspected. The contamination of the photoreceptor was evaluated according to the following criteria. [Evaluation criteria] A: No toner fusion was observed on the photoreceptor. B: A slight amount of toner fusion is observed on the photosensitive member, but it does not appear on the image. C: White dots are missing from the image on a solid black image. D: Shooting star-shaped image voids are observed from white dots on a solid black image.

[0137] <Environmental stability evaluation> The image reproduction tester and a toner cartridge filled with the evaluation toner were left in a high-temperature, high-humidity environment of 32.5°C / 80% RH for at least one day, after which 1,000 test charts with a print ratio of 1% were printed using the image reproduction tester. The image reproduction tester and a toner cartridge filled with the evaluation toner were then left in a low-temperature, low-humidity environment of 10°C / 10% RH for at least one day, after which 10,000 test charts with a print ratio of 1% were printed using the image reproduction tester. The charge amount (μC / g) of the toner on the developer carrier in the toner cartridge was measured using a blow-off powder charge amount measuring device TB-200 (manufactured by Toshiba Chemical Co.) to evaluate environmental stability. The greater the ratio of charge amount in a high-temperature, high-humidity environment to that in a low-temperature, low-humidity environment, the better the environmental stability of the toner. The environmental stability evaluation criteria were determined as follows: Evaluation was made based on the following criteria based on the value of (charge amount after printing 1000 sheets in a high-temperature, high-humidity environment) / (charge amount after printing 1000 sheets in a low-temperature, low-humidity environment)×100. [Evaluation criteria] A: 80% or more B: 75% or more but less than 80% C: 70% or more but less than 75% D: Less than 70%

[0138] <Low temperature fixability evaluation> For the low-temperature fixability evaluation, the fixing device of the evaluation machine was taken out and the temperature of the fixing device was set arbitrarily. An external fixing unit was used that had been modified to enable the process speed to be 410 mm / sec. Using the above device, the toner amount per unit area was set to 0.5 mg / cm under normal temperature and humidity conditions (temperature 25°C, humidity 50% RH). 2 The unfixed solid black image was passed through a fixing unit whose temperature was adjusted to the set temperature. The resulting fixed image was fixed at 4.9 kPa (50 g / cm 2 The image was rubbed back and forth five times with Silbon paper under a load of 1000 psi (0.01 psi), and the temperature at which the density loss before and after the rubbing test was 10% or less was defined as the fixing temperature. The image density was measured using a Macbeth densitometer (manufactured by Macbeth) which is a reflection densitometer, with an SPI filter. (Evaluation criteria) A: Fixing temperature is less than 200°C B: Fixing temperature is 200°C or higher and less than 210°C C: Fixing temperature is 210°C or higher and less than 220°C D: Fixing temperature is 220°C or higher [Table 8-1] [Table 8-2]

[0139] The present disclosure includes the following configurations. (Configuration 1) A toner having toner particles containing a binder resin and an external additive, The external additive contains rutile-anatase type titania particles and hydrotalcite particles. The toner is characterized in that the rutile / anatase ratio of the rutile-anatase titania particles, which is a ratio based on peak intensity measured by powder X-ray diffraction, is 15 / 85 to 50 / 50. (Configuration 2) The toner according to Configuration 1, wherein L1 / L2 is 1.0 to 5.0, where L1 (nm) is the number average value of the major axis diameter of the primary particles of the rutile-anatase type titania particles and L2 (nm) is the number average value of the minor axis diameter of the primary particles of the rutile-anatase type titania particles. (Configuration 3) 3. The toner according to configuration 1 or 2, wherein the rutile-anatase titania particles have a number average major axis diameter L1 of 10.0 to 100.0 nm. (Configuration 4) 4. The toner according to any one of configurations 1 to 3, wherein the number average value L3 of the major axis diameter of the primary particles of the hydrotalcite particles is 40 to 1100 nm. (Configuration 5) The toner according to any one of configurations 1 to 4, wherein, in the toner, when the content of the rutile-anatase type titania particles relative to 100 parts by mass of the toner particles is M1 (parts by mass), and the content of the hydrotalcite particles relative to 100 parts by mass of the toner particles is M2 (parts by mass), M1 / M2 is 0.5 to 5.0. (Configuration 6) The toner according to any one of Configurations 1 to 5, wherein L1 / L3 is 0.030 to 0.900, where L1 (nm) is the number average value of the major axis diameter of the primary particles of the rutile-anatase titania particles and L3 (nm) is the number average value of the major axis diameter of the primary particles of the hydrotalcite particles. (Configuration 7) The volume resistivity ρV of the rutile-anatase titania particles is 1×10 8 ~1×10 12 7. The toner according to any one of configurations 1 to 6, wherein the toner has a viscosity of Ω·cm. (Configuration 8) The toner according to any one of Configurations 1 to 7, wherein L1 (nm) is the number average of the major axis diameter of the primary particles of the rutile-anatase type titania particles, L2 (nm) is the number average of the minor axis diameter of the primary particles of the rutile-anatase type titania particles, and ρV is the volume resistivity of the rutile-anatase type titania particles, and L1, L2, and ρV satisfy the following formula (1): 2.4 ≦ (log 10 (ρV)) / (L1 / L2) ≦ 8.0 (1) (Configuration 9) the toner particles contain a wax, 9. The toner according to any one of configurations 1 to 8, wherein the wax comprises an ester wax. (Configuration 10) 10. The toner according to claim 9, wherein the wax is behenyl behenate. (Configuration 11) The binder resin contains 50.0% by mass or more of polyester resin A, 11. The toner according to any one of configurations 1 to 10, wherein the polyester resin A contains 60 mol % or more of monomer units corresponding to isophthalic acid based on all monomer units corresponding to polycarboxylic acids. (Configuration 12) 12. The toner according to any one of Configurations 1 to 11, wherein the toner particles contain at least one selected from the group consisting of dodecylbenzenesulfonic acid and dodecylbenzenesulfonic acid salts.

Claims

1. A toner having toner particles containing a binder resin and an external additive, The external additive contains rutile-anatase type titania particles and hydrotalcite particles. The toner is characterized in that the rutile / anatase ratio of the rutile-anatase titania particles, which is a ratio based on peak intensity measured by powder X-ray diffraction, is 15 / 85 to 50 / 50.

2. 2. The toner according to claim 1, wherein L1 / L2 is 1.0 to 5.0, where L1 (nm) is the number average major axis diameter of the primary particles of the rutile-anatase type titania particles and L2 (nm) is the number average minor axis diameter of the primary particles of the rutile-anatase type titania particles.

3. 2. The toner according to claim 1, wherein the rutile-anatase titania particles have a number average major axis diameter L1 of 10.0 to 100.0 nm.

4. 2. The toner according to claim 1, wherein the number average value L3 of the major axis diameter of the primary particles of the hydrotalcite particles is 40 to 1100 nm.

5. 2. The toner according to claim 1, wherein, in the toner, when the content of the rutile-anatase type titania particles relative to 100 parts by mass of the toner particles is M1 (parts by mass), and the content of the hydrotalcite particles relative to 100 parts by mass of the toner particles is M2 (parts by mass), M1 / M2 is 0.5 to 5.

0.

6. 2. The toner according to claim 1, wherein L1 / L3 is 0.030 to 0.900, where L1 (nm) is the number average value of the major axis diameter of the primary particles of the rutile-anatase type titania particles and L3 (nm) is the number average value of the major axis diameter of the primary particles of the hydrotalcite particles.

7. The volume resistivity ρV of the rutile-anatase titania particles is 1×10 ８ ~1 x 10 １２ 2. The toner according to claim 1, wherein the toner has a viscosity of Ω·cm.

8. 2. The toner according to claim 1, wherein L1 (nm) is the number average major axis diameter of the primary particles of the rutile-anatase type titania particles, L2 (nm) is the number average minor axis diameter of the primary particles of the rutile-anatase type titania particles, and ρV is the volume resistivity of the rutile-anatase type titania particles, and L1, L2, and ρV satisfy the following formula (1): 2.4 ≦ (log １０ (ρV)) / (L1 / L2) ≦ 8.0 (1)

9. the toner particles contain a wax, 10. The toner of claim 1, wherein the wax comprises an ester wax.

10. 10. The toner of claim 9, wherein said wax is behenyl behenate.

11. The binder resin contains 50.0% by mass or more of polyester resin A, 2. The toner according to claim 1, wherein the polyester resin A contains 60 mol % or more of monomer units corresponding to isophthalic acid based on all monomer units corresponding to polycarboxylic acids.

12. 12. The toner according to claim 1, wherein the toner particles contain at least one selected from the group consisting of dodecylbenzenesulfonic acid and dodecylbenzenesulfonate salts.

Images