Toner and toner manufacturing method

Abstract

To provide a toner which can have excellent low temperature fixability when paper after having been left under normal temperature and high humidity environment is used, and prevents image chipping in a fixed image when an image is output under high temperature and high humidity environment for a long time.SOLUTION: A toner contains toner particles containing a resin component and a wax, and inorganic fine particles on the surface of the toner particles, in which in cross section observation of the toner particles, a domain containing the wax is observed, when a region to 600 nm inside from the surface of the toner particles is determined as a first region, an occupancy area of a domain having a major axis of 10-120 nm in the first region is represented by R1(%), and an occupancy area of all the domains in the first region is represented by R2(%), the R1(%) and the R2(%) satisfy Expression (1) and Expression (2).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a toner used in an electrophotographic image forming apparatus. [Background technology]

[0002] In recent years, there has been an increasing demand for power saving in electrophotographic image forming apparatuses. To meet this demand for power saving, toners with excellent low-temperature fixability that can be fixed to media such as paper even at low temperatures have been studied.

[0003] A known method for improving the low-temperature fixability of toner is to lower the glass transition temperature of the toner's resin component. However, when paper that has been left in a room-temperature, high-humidity environment is used, part of the heat required for fixation is used to evaporate the moisture in the paper, making it difficult to provide sufficient heat to the toner. As a result, a higher fixation temperature is required to fix the toner, making fixation at low temperatures difficult. On the other hand, if the glass transition temperature of the toner's resin component is lowered too much, the toner's heat storage stability deteriorates, so a method that contributes to further improving the low-temperature fixability of toner is needed.

[0004] Therefore, in order to improve the low-temperature fixability of toner, toners that make it easier to melt the vicinity of the surface of toner particles, thereby making it easier for the entire toner particle to melt quickly during fixing, have been studied. Patent Documents 1 and 2 propose toners in which wax is unevenly distributed near the surface of toner particles. It is believed that by having wax near the surface of toner particles, the wax makes it easier for the wax to quickly melt the resin near the surface of the toner particles during fixing, and excellent low-temperature fixability can be achieved even when paper that has been left in a room-temperature, high-humidity environment is used. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-62041 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-224248 Summary of the Invention [Problem to be solved by the invention]

[0006] However, as a result of investigations by the present inventors into the toners described in Patent Documents 1 and 2, it was found that when image output is performed for a long period of time in a high-temperature, high-humidity environment, image defects tend to occur in the fixed image.

[0007] The present disclosure provides a toner that can have excellent low-temperature fixing properties when used with paper that has been left in a normal temperature, high humidity environment, and that is less likely to cause image defects in fixed images when image output is performed for a long period of time in a high temperature, high humidity environment. [Means for solving the problem]

[0008] The present disclosure provides a toner comprising toner particles containing a resin component and a wax, and inorganic fine particles on the surfaces of the toner particles, In the cross-sectional observation of the toner particle, domains comprising said wax are observed; a region extending from the surface of the toner particle to a depth of 600 nm inside the toner particle is defined as a first region; The occupied area ratio of the domains having a major axis of 10 to 120 nm in the first region is R1 (%), When the occupied area ratio of all the domains in the first region is R2 (%), The R1 (%) and the R2 (%) satisfy the following formula (1) and formula (2): 2.0 ≦ R1(%) ≦ 15.0 ··· Formula (1) R1(%) / R2(%) ≧ 0.60 ··· Formula (2) The toner is characterized by the above. [Effects of the Invention]

[0009] According to the present disclosure, a toner can be provided that has excellent low-temperature fixing properties when used with paper that has been left in a normal temperature, high humidity environment, and that is less likely to cause image defects in fixed images when image output is performed for a long period of time in a high temperature, high humidity environment. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B are schematic diagrams of a cross section of a toner particle for explaining a hypothetical mechanism for achieving the effects of the present disclosure. [Figure 2] FIG. 1 is a schematic diagram of a rotating body that can be used in a mixing device used in an external addition step of the present disclosure. [Figure 3] FIG. 1 is a schematic diagram of a rotating body that can be used in a mixing device used in an external addition step of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] The expressions "xx or more and xx or less" or "xx to xx" that represent a numerical range mean a numerical range that includes the endpoints, that is, the lower limit and the upper limit, unless otherwise specified.

[0012] The cross-sectional observation of the toner particles according to the present disclosure is preferably performed using a scanning transmission electron microscope.

[0013] Hereinafter, the term "wax domain" refers to a domain containing wax. Furthermore, the term "micro wax domain" refers to a wax domain having a major axis of 10 to 120 nm, and the term "coarse wax domain" refers to a wax domain having a major axis of more than 120 nm.

[0014] <The cause of image defects in high-temperature, high-humidity environments and the background to the invention> The present inventors speculate as follows why image defects occur in fixed images when images are output for a long period of time in a high-temperature, high-humidity environment using the toners disclosed in Patent Documents 1 and 2.

[0015] Toner particles with wax dispersed near the surface of the toner particles tend to have excellent low-temperature fixability. The inventors believe this is because the contact area between the dispersed wax and the resin near the surface of the toner particles is large, and the wax and resin are compatible with each other during fixation, making it easier to melt the resin near the surface of the toner particles with a small amount of heat. It is also speculated that melting the resin near the surface of the toner particles with a small amount of heat makes it easier for the entire toner particle to melt quickly. This is an advantageous characteristic because it allows for lower fixation temperatures in electrophotographic image forming apparatuses with high process speeds.

[0016] However, it is believed that toner particles with wax dispersed near the surface of the toner particles may have inorganic fine particles on the surface that are easily embedded in the toner particles. This is thought to be particularly pronounced under high temperature and high humidity conditions. When inorganic fine particles on the surface of the toner particles are embedded in the toner particles, the fluidity of the toner particles is likely to decrease, and friction between the developing member and the toner particles in the image forming apparatus is less likely to occur, making it difficult for the toner particles to be sufficiently charged. As a result, it is thought that toner that is not sufficiently charged is likely to remain in parts on the developing member, and these parts are likely to cause image defects in the electrophotographic image.

[0017] The present inventors speculate that the reason why the toners disclosed in Patent Documents 1 and 2 are prone to image defects in a high-temperature, high-humidity environment is that there are many coarse wax domains near the surface of the toner particles, and the inorganic fine particles on the surface of the toner particles are easily embedded in the toner particles. While minute wax domains are unlikely to reduce the elasticity near the surface of the toner particles, it is thought that the elasticity near the surface of the toner particles in the areas where coarse wax domains exist is likely to reduce.

[0018] As a result of further investigation based on the above considerations, it was found that a toner containing minute wax domains in the vicinity of the surface of the toner particles in the following ratio and having the amount of the total wax domains relative to the minute wax domains controlled to the following ratio is less likely to cause image defects.

[0019] Content ratio of minute wax domains: When the occupied area ratio of wax domains with a major axis of 10 to 120 nm in the region from the surface of the toner particle to the inside by 600 nm (i.e., near the surface of the toner particle) is R1 (%), R1 is 2.0 to 15.0%.

[0020] Ratio of the total amount of wax domains to the minute wax domains: When the occupied area ratio of all wax domains in the region from the surface of the toner particle to the inside of 600 nm is R2 (%), R1 (%) / R2 (%) is 0.60 or more.

[0021] <Expected mechanism by which the effects of this disclosure will be realized> The mechanism by which the toner having the above-described configuration exhibits the effects of the present disclosure will be described with reference to FIG.

[0022] FIG. 1 is an example of a schematic cross-sectional view of a toner particle according to the present disclosure.

[0023] In the region (near-surface region) from contour line 2 on the surface of the toner particle to contour line 3, which is 600 nm inward, minute wax domains 1 occupy a specific percentage of the area, and the area of ​​coarse wax domains 5 is a specific percentage or less of the above-mentioned area. With a toner having this configuration, minute wax domains 1 are easily dispersed in the near-surface region of the toner particles, which is thought to facilitate melting of the resin near the surface of the toner particles during fixing, making it easy to obtain a toner with excellent low-temperature fixing properties. Furthermore, because the content of coarse wax domains 5 is not excessive in the near-surface region, inorganic fine particles 6 are less likely to be embedded in the toner particles under high-temperature and high-humidity conditions, and the fluidity of the toner is less likely to decrease. As a result, the toner particles are more likely to be sufficiently charged on the developing member, making it less likely that image defects will occur in the fixed image.

[0024] <Wax> <Occupied area ratio of wax domains near the surface of toner particles> In cross-sectional observation of a toner particle, when a region extending from the surface of the toner particle to a depth of 600 nm inward is defined as a first region, and the occupied area ratio of wax domains having a major axis of 10 to 120 nm in the first region is defined as R1 (%), the following formula (1) is satisfied. The inventors speculate that wax domains having a major axis of less than 10 nm are too small in size and therefore do not easily become compatible with the resin near the surface of the toner particle, and therefore do not easily contribute to improving the low-temperature fixability of the toner. 2.0 ≦ R1(%) ≦ 15.0 ··· Formula (1)

[0025] When R1 is 2.0% or more, a toner having excellent low-temperature fixability is easily obtained. Therefore, R1 is 2.0% or more, preferably 3.0% or more, and more preferably 6.0% or more. Furthermore, when R1 is 15.0% or less, the resin component near the surface of the toner particles is less likely to melt excessively, and a toner having excellent heat-resistant storage stability is easily obtained. Therefore, R1 is 15.0% or less, preferably 12.0% or less, more preferably 10.0% or less, and even more preferably 9.0% or less.

[0026] In addition, when observing a cross section of a toner particle, when the occupied area ratio of all wax domains in the first region is R2 (%), the above R1 and R2 satisfy the following formula (2). R1(%) / R2(%) ≧ 0.60 ··· Formula (2)

[0027] By satisfying the above formula (1) and having R1(%) / R2(%) of 0.60 or more, it is believed that the amount of coarse wax domains is sufficiently small relative to the amount of minute wax domains present in the surface vicinity region of the toner particles, and inorganic fine particles are less likely to be embedded in the toner particles. Therefore, R1(%) / R2(%) is 0.60 or more, and preferably 0.80 or more. There is no particular upper limit, but it is preferable that R1(%) / R2(%) is 0.97 or less.

[0028] Furthermore, the above R2 is preferably 25.0% or less. When R2 is 25.0% or less, it is thought that the amount of wax near the surface of the toner particles is unlikely to become excessive, and inorganic fine particles are unlikely to be embedded in the toner particles. Therefore, R2 is preferably 25.0% or less, more preferably 20.0% or less, and even more preferably 15.0% or less. 10.0% or less is even more preferable. There is no particular lower limit, but it is preferably 2.0% or more, more preferably 3.0% or more, more preferably 5.0% or more, and even more preferably 7.0% or more.

[0029] The occupied area ratio of the wax domain in the first region means the ratio of the area of ​​the wax domain to the area of ​​the first region.

[0030] <Major axis of wax domains near the surface of toner particles> When observing the cross section of a toner particle, the standard deviation of the major axis of all wax domains in the first region is preferably 40 nm or less. If the standard deviation is 40 nm or less, the size of the wax domains present near the surface of the toner particle is less likely to vary, and the low-temperature fixability and fluidity of the toner are less likely to vary. Therefore, the standard deviation is preferably 40 nm or less, and more preferably 30 nm or less. There is no particular lower limit, but it is preferably 10 nm or more.

[0031] Furthermore, when the number average value of the major axes of all wax domains in the first region is defined as A1, A1 is preferably 50 to 200 nm. When A1 is 50 nm or more, the size of the wax domains near the surface of the toner particles is less likely to become too small, and a toner with excellent low-temperature fixability is more likely to be obtained. Therefore, A1 is preferably 50 nm or more, and more preferably 75 nm or more. When A1 is 200 nm or less, the size of the wax domains near the surface of the toner particles is less likely to become too large, and a toner with excellent low-temperature fixability and less likelihood of image defects is more likely to be obtained. Therefore, A1 is preferably 200 nm or less, more preferably 150 nm or less, more preferably 100 nm or less, and even more preferably 85 nm or less.

[0032] The above R1, R2, standard deviation, and A1 can be controlled by the toner particle production conditions (particularly the cooling step and annealing step), the conditions of the external addition step, the type of wax, and the amount of wax added. The present inventors speculate that in order for the above R1, R2, standard deviation, and A1 to satisfy the above preferred values, a step of microcrystallizing the wax contained in the toner particles and a step of microcrystallizing the wax present in the vicinity of the surface of the toner particles are necessary.

[0033] Examples of a process for microcrystallizing the wax contained in the toner particles include a process of rapidly cooling the toner particles and then annealing them, which will be described later. This is thought to be because rapid cooling of the toner particles makes it easier for crystalline nuclei of the wax contained in the toner particles to form, and subsequent annealing promotes crystal growth of the crystalline nuclei, making it easier for minute wax domains to form within the toner particles.

[0034] Furthermore, a process for microcrystallizing the wax present near the surface of the toner particles can be exemplified by a process of externally adding inorganic fine particles to the toner particles at a temperature at which the wax is likely to crystallize. It is presumed that by externally adding inorganic fine particles to the toner particles at this temperature, the uncrystallized wax present near the surface of the toner particles is likely to form a large number of crystal nuclei due to the impact from the inorganic fine particles. As a result, it is thought that minute wax domains are likely to be formed near the surface of the toner particles.

[0035] In cross-sectional observation of a toner particle, when a region from 600 nm to 1500 nm from the surface of the toner particle is defined as a second region, and the number average value of the major axes of all wax domains in the second region is defined as A2 (nm), it is preferable that A1 (nm) and A2 (nm) satisfy the following formula (3): A2-A1 ≧ 30 ··· Formula (3)

[0036] When A2-A1 is 30 or more, it is believed that the relatively large wax domains contained in the region (second region) slightly closer to the center of the toner particles tend to exude during fixing as the surface vicinity of the toner particles melts, making it easier to obtain a toner with excellent low-temperature fixability and releasability. Therefore, A2-A1 is preferably 30 or more, more preferably 40 or more. There is no particular upper limit, but it is preferably 70 or less.

[0037] Furthermore, the above A2 is preferably 110 to 210 nm. When A2 is 110 nm or more, the size of the wax present in the region (second region) slightly closer to the center of the toner particle than near the surface is less likely to become too small, making it easier to obtain a toner with excellent releasability. Therefore, A2 is preferably 110 nm or more, and more preferably 125 nm or more. Furthermore, when A2 is 210 nm or less, it is thought that inorganic fine particles are less likely to be embedded in the toner particle, making it easier to obtain a toner that is less likely to cause image defects. Therefore, A2 is preferably 210 nm or less, more preferably 160 nm or less, and even more preferably 140 nm or less.

[0038] Furthermore, when observing the cross section of a toner particle, a region 1500 nm or more from the surface of the toner particle is defined as a third region, and the number average value of the major axes of all wax domains in the third region is defined as A3 (nm). It is preferable that A1, A2, and A3 satisfy the following formula (4). A1 < A2 < A3 ··· Formula (4)

[0039] When A1, A2, and A3 satisfy the formula (4), the size of the wax domain tends to decrease from the center of the toner particle toward the surface, making it easier to obtain a toner having excellent releasability and preventing the inorganic fine particles from being embedded in the toner particle.

[0040] Furthermore, it is preferable that the above A3 (nm) satisfies the following formula (5). 800 ≦ A3(nm) ··· Formula (5)

[0041] By having A3 of 800 nm or more, a sufficient amount of wax can be easily contained in the center of the toner particle. As a result, as the surface of the toner particle melts during fixing, the entire toner particle melts rapidly, and the wax easily seeps out to the toner surface, making it easier to obtain a toner with excellent low-temperature fixing properties and releasability. Therefore, A3 is preferably 800 nm or more, and more preferably 1000 nm or more. The upper limit is 3000 nm or less.

[0042] The above A2 and A3 can be controlled by the type of wax used in the production of the toner and the amount of wax added.

[0043] <Types of wax> The toner particles preferably contain an ester wax, which is thought to be compatible with the resin component, and therefore melts the resin component easily during fixing, making it easier to obtain a toner with excellent low-temperature fixing properties.

[0044] Since a toner having excellent low-temperature fixability can be easily obtained, the ratio of the mass of the ester wax to the mass of the resin component contained in the toner particles is preferably 10.0 to 20.0% by mass.

[0045] The ester wax contained in the toner particles is not particularly limited, and the following ester waxes can be used.

[0046] Monofunctional ester waxes such as behenyl stearate, behenyl behenate, and stearyl behenate; bifunctional ester waxes such as ethylene glycol distearate, dibehenyl sebacate, and hexanediol dibehenate; trifunctional ester waxes such as glycerin tribehenate; tetrafunctional ester waxes such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate; hexafunctional ester waxes such as dipentaerythritol hexastearate and dipentaerythritol hexapalmitate; multifunctional ester waxes such as polyglycerin behenate; and natural ester waxes such as carnauba wax and rice wax.

[0047] Furthermore, it is preferable that the toner particles contain an ester wax and a hydrocarbon wax. By containing not only an ester wax but also a hydrocarbon wax in the toner particles, minute wax domains are easily formed in the vicinity of the surface of the toner particles. This is presumably because the hydrocarbon wax has a high crystallization rate and is easily microcrystallized together with the ester wax in the vicinity of the toner particles.

[0048] In order to easily obtain a toner that is less likely to cause image defects, the ratio of the mass of the hydrocarbon wax to the mass of the resin component contained in the toner particles is preferably 5.0 to 15.0% by mass.

[0049] The hydrocarbon wax contained in the toner is not particularly limited, and the following hydrocarbon waxes can be used.

[0050] Hydrocarbon waxes and derivatives thereof produced by the Fischer-Tropsch process; petroleum waxes and derivatives thereof such as paraffin wax, microcrystalline wax, and petrolatum; polyolefin waxes and derivatives thereof such as polyethylene wax and polypropylene wax; higher aliphatic alcohols; long-chain fatty acids, etc.

[0051] <Crystallization peak temperature> The crystallization peak temperature of the wax is preferably 60 to 80°C. It is presumed that when the crystallization peak temperature is within the above range, the wax can be easily microcrystallized within the toner particles. As a result, it is preferable because toner particles that satisfy the above formulas (1) and (2) are easily obtained. The method for measuring the crystallization peak will be described later. The crystallization peak of the wax can be controlled by the type of wax contained in the toner.

[0052] <Wax content> The ratio of the mass of the wax to the mass of the resin component contained in the toner particles is preferably 10.0 to 35.0% by mass. By containing the wax in the toner particles in this ratio, it is easy to obtain a toner that is less likely to cause image defects and has excellent low-temperature fixability and releasability. More preferably, the ratio is 20.0 to 35.0% by mass.

[0053] <Inorganic fine particles> <Dispersion of inorganic fine particles> The dispersion degree of the inorganic fine particles on the surface of the toner particles is preferably 2.0 nm or less. The dispersion degree is calculated by the following formula:

[0054]

number

[0055] (n: number of inorganic fine particles, dn min: distance between any inorganic fine particle and the nearest inorganic fine particle, dave: average value of distance between each inorganic fine particle and the nearest inorganic fine particle in one toner particle) The smaller the dispersity, the closer the distance between the inorganic fine particles present on the surface of the toner particles. When the dispersity is 2.0 or less, the inorganic fine particles are likely to be uniformly dispersed on the surface of the toner particles. As a result, the inorganic fine particles on the surface of the toner particles can reduce friction between the toner particles, which is thought to make it difficult for the toner fluidity to decrease, and therefore, image defects are unlikely to occur in the fixed image.

[0056] The degree of dispersion of the inorganic fine particles on the toner surface can be controlled by the conditions of the external addition step, the type of inorganic fine particles, and the amount of inorganic fine particles added.

[0057] <Inorganic fine particles (X)> The inorganic fine particles preferably contain inorganic fine particles (X) having a major axis of primary particles of 60 to 300 nm or less. Examples of inorganic fine particles (X) that can be used include fine particles of silica, titanium oxide, alumina, strontium titanate, and the like. From the viewpoint of uniform charging of the toner and improving fluidity, the inorganic fine particles (X) are preferably silica fine particles. Examples of silica fine particles include wet silica produced by precipitation methods, sol-gel methods, and the like, and dry silica produced by deflagration methods, fumed methods, and the like. From the viewpoint of dispersibility on the surface of toner particles, wet silica fine particles produced by sol-gel methods, etc., are preferred.

[0058] <Relationship between the coverage rate X (%) of inorganic fine particles (X) and the amount of wax near the surface of toner particles> When the coverage of the inorganic fine particles (X) is X (%), it is preferable that the coverage X (%) and the above R2 (%) satisfy the following formula (6). X ≦ R2 ··· Formula (6)

[0059] When the relationship between the coverage rate X and the occupied area rate R2 of the wax domain near the surface of the toner particle satisfies formula (6), a toner having excellent low-temperature fixability is easily obtained.

[0060] Furthermore, the coverage ratio X is preferably 1.0 to 8.0. When the coverage ratio X is 1.0 or more, the fluidity of the toner is likely to be improved, and image defects are unlikely to occur in the fixed image. Therefore, the coverage ratio X is preferably 1 or more, more preferably 2.0 or more, and even more preferably 4.0 or more. When the coverage ratio X is 8.0 or less, the amount of inorganic fine particles present on the surface of the toner particles is unlikely to become excessive. Therefore, it is preferably 8.0 or less, and more preferably 6.0 or less.

[0061] The coverage X of the inorganic fine particles (X) can be controlled by the production conditions in the external addition step, the type of inorganic fine particles, and the amount of inorganic fine particles added.

[0062] <Inorganic fine particles (Y)> In order to improve the fluidity and chargeability of the toner, the inorganic fine particles preferably contain inorganic fine particles (Y) having a primary particle length of 5 to 30 nm.

[0063] Examples of inorganic fine particles (Y) include fluororesin powders such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder; silica fine particles such as wet-process silica and dry-process silica, fine titanium oxide powder, fine alumina powder, treated silica, fine titanium oxide powder, and fine alumina powder which have been surface-treated with a silane compound, a titanium coupling agent, or silicone oil; oxides such as zinc oxide and tin oxide; double oxides such as strontium titanate, barium titanate, calcium titanate, strontium zirconate, and calcium zirconate; and carbonate compounds such as calcium carbonate and magnesium carbonate.

[0064] Preferable inorganic fine particles (Y) are dry silica fine particles. More preferably, they are hydrophobically treated dry silica fine particles. Examples of dry silica fine particles include the following.

[0065] AEROSIL (Nippon Aerosil Co., Ltd.) 130, 200, 300, 380, TT600, MOX170, MOX80, COK84, Ca-O-SiL (CABOT Co.) M-5, MS-7, MS-75, HS-5, EH-5, Wacker HDK N 20 (WACKER-CHEMIE GMBH) V15, N20E, T30, T40, DC Fine Silica (Dow Corning Co.), Fransol (Fransil).

[0066] <Resin component> The resin component is preferably a binder resin, that is, toner particles containing a binder resin and a wax.

[0067] The resin contained in the resin component is not particularly limited, and the following can be used, for example.

[0068] Homopolymers of styrene and its substituted derivatives, such as polystyrene and polyvinyltoluene; styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-butyl acrylate copolymers, styrene-octyl acrylate copolymers, styrene-dimethylaminoethyl acrylate copolymers, styrene-methyl methacrylate copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-dimethylaminoethyl methacrylate copolymers, styrene-vinyl methyl ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resins, polyesters, polyamide resins, epoxy resins, and polyacrylic acid resins. These may be used alone or in combination. Among these, styrene-acrylic resins, such as styrene-butyl acrylate copolymers, are particularly preferred in terms of development properties, fixability, and the like. The content of the styrene acrylic resin in the resin component is preferably 80.0 to 100.0% by mass.

[0069] <Styrene acrylic resin> Examples of polymerizable monomers corresponding to the monomer units constituting the styrene-acrylic resin include the following.

[0070] As the styrene-based polymerizable monomer, styrene; α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene and other styrene-based polymerizable monomers.

[0071] Examples of acrylic polymerizable monomers include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, cyclohexyl acrylate, and phenyl acrylate.

[0072] Examples of methacrylic polymerizable monomers include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, n-octyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate.

[0073] Other examples include monomers such as acrylonitrile, methacrylonitrile, and acrylamide.

[0074] The method for producing the styrene-acrylic resin is not particularly limited. The resin component may be a combination of resins other than the styrene-acrylic resin.

[0075] <Amorphous polyester> The resin component may contain an amorphous polyester, and the amorphous polyester may be selected from saturated polyester, unsaturated polyester, or both. The content of the amorphous polyester in the resin component is preferably 0.1 to 10.0% by mass, more preferably 0.1 to 5.0% by mass.

[0076] The amorphous polyester is a resin composed of an alcohol component and a carboxylic acid component, and examples of both components are given below.

[0077] Examples of the alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, bisphenols represented by the following formula (A) and derivatives thereof, and diols represented by the following formula (B).

[0078] [ka]

[0079] (In formula (A), R is (-CH2-CH2-) or (-CH2-CH2-CH2-). x and y are each an integer of 0 or more, and the average value of x+y is 0 to 10.)

[0080] [ka]

[0081] (In formula (B), R' is any one of the above (B1) to (B3). x' and y' are integers of 0 or greater, and the average value of x'+y' is 0 to 10.) The alcohol component of the amorphous polyester is preferably a bisphenol represented by formula (A) or a derivative thereof. It is more preferable that the average value of x+y in formula (A) is 1 to 4. It is more preferable that R in formula (A) is (—CH2—CH2—).

[0082] Examples of the carboxylic acid component include benzenedicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride; alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid; alkenylsuccinic acids or alkylsuccinic acids such as n-dodecenylsuccinic acid and n-dodecylsuccinic acid; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid; and acid anhydrides or lower alkyl esters of the above-mentioned carboxylic acids.

[0083] The carboxylic acid component of the amorphous polyester is preferably a benzenedicarboxylic acid such as terephthalic acid or isophthalic acid, and more preferably terephthalic acid.

[0084] <Toner properties> <Toner glass transition temperature> The glass transition temperature of the toner is preferably 45 to 55°C, as this makes it easier to obtain a toner with excellent low-temperature fixability.

[0085] <Toner weight average particle diameter (D4)> The weight-average particle diameter (D4) of the toner is preferably 5.0 to 10.0 μm. When the weight-average particle diameter (D4) of the toner is within the above range, the charge stability, fixability, and developability of the toner are easily maintained appropriately. More preferably, the D4 of the toner is 5.0 to 9.0 μm.

[0086] The weight average particle size (D4) of the toner can be controlled by the pulverization conditions when the toner is produced by a pulverization method, or by the amount of dispersion stabilizer, the rotation speed of the stirrer, etc. when the toner is produced in an aqueous medium.

[0087] Similarly, the weight average particle diameter (D4) of the toner particles is preferably 5.0 to 10.0 μm.

[0088] The particle diameter of the toner particles is preferably 4.0 to 9.0 μm.

[0089] <Various additives> If necessary, the toner may contain one or more additives selected from colorants, magnetic materials, charge control agents, fluidizing agents, etc. Various additives used in the toner will be specifically described below.

[0090] <Coloring agent> Examples of colorants include: As a black colorant, carbon black, magnetic material, or a material toned to black using the yellow, magenta, and cyan colorants shown below.

[0091] Yellow colorants include monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

[0092] Magenta colorants include monoazo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

[0093] Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds.

[0094] <Magnetic material> Examples of magnetic materials include those containing magnetic iron oxides such as black iron tetroxide and gamma-iron oxide as the main component, and containing elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, silicon, etc. The magnetic material may be in the form of a polyhedron, octahedron, hexahedron, sphere, needle, scale, etc., but those with little anisotropy such as a polyhedron, octahedron, hexahedron, or sphere are preferred in terms of increasing image density.

[0095] <Charge control agent> Examples of negatively charged charge control agents include the following:

[0096] Monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic and dicarboxylic acid-based metal compounds, aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, boron compounds, quaternary ammonium salts, calixarenes, resin-based charge control agents.

[0097] Examples of positively charged charge control agents include the following:

[0098] Nigrosine and nigrosine modified with fatty acid metal salts, etc.; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, etc., and onium salts such as phosphonium salts that are analogs of these, and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (lacquering agents include phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.); metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, and dicyclohexyltin oxide; diorganotinborates such as dibutyltinborate, dioctyltinborate, and dicyclohexyltinborate; resin-based charge control agents.

[0099] These may be used alone or in combination of two or more.

[0100] Among these, metal-containing salicylic acid compounds are preferred, with those in which the metal is aluminum or zirconium being more preferred, and aluminum salicylate compounds are even more preferred.

[0101] Similarly, it is also preferable to use a polymer or copolymer having a sulfonic acid group, a sulfonate group or a sulfonate ester group, a salicylic acid moiety, or a benzoic acid moiety as the resin-based charge control agent.

[0102] The content of the charge control agent is preferably 0.01 to 20.0 parts by mass, and more preferably 0.05 to 10.0 parts by mass, relative to 100.0 parts by mass of the resin component.

[0103] <Toner manufacturing method> The toner may be produced by any method, such as a pulverization method, a suspension polymerization method, an emulsion aggregation method, a solution suspension method, etc., but is not limited to these. Production by the suspension polymerization method is preferred because it is easy to control the state of existence of the wax contained in the toner particles.

[0104] In addition, the cooling step and the annealing step will be described below as preferred steps in the manufacturing method for producing the toner of the present disclosure.

[0105] As a cooling step, it is preferable to carry out a cooling step in which the temperature is lowered from the cooling start temperature to the cooling final temperature before sending the dispersion of toner particles after the volatile component removal step to the next step. It is believed that the ease of formation of wax domain crystal nuclei in the toner particles can be controlled by the conditions of the cooling step. The cooling conditions can be changed by changing the cooling start temperature, cooling rate, and cooling final temperature.

[0106] When the crystallization peak temperature of the wax is Ta, the toner manufacturing method preferably includes a step of holding a dispersion of toner particles at Ta+15° C. to Ta+35° C. It is presumed that by including a step of holding the toner particles in this temperature range, the fluidity of the wax in the toner particles improves, making it easier to disperse the wax in the toner particles.

[0107] It is also preferable to have a cooling step in which the dispersion liquid that has been subjected to the above-mentioned holding step is cooled from the cooling start temperature to the cooling final temperature at a cooling rate of 40.0 to 200.0°C / min.

[0108] It is presumed that when the cooling rate is within the above range, the wax crystallizes sufficiently quickly during cooling, making it easier to form crystal nuclei of wax domains within the toner particles.The cooling rate is more preferably 100.0 to 140.0°C / min.

[0109] The cooling start temperature is preferably from Ta+15 (°C) to Ta+35 (°C), and the cooling end temperature is preferably from Ta-35 (°C) to Ta-20°C (°C).

[0110] If the cooling start temperature is within the above range, the wax is easily melted in the toner particles and easily dispersed throughout the toner particles, which is preferable.

[0111] When the cooling temperature is within the above range, the wax in the toner particles rapidly crystallizes, which is thought to facilitate the formation of a large number of wax crystal nuclei in the toner particles. The formation of a large number of crystal nuclei is thought to facilitate the suppression of wax domains from crystallizing and coalescing, and facilitate the formation of minute wax domains.

[0112] The dispersion liquid after the cooling step is preferably subjected to an annealing step to promote crystallization of the wax. It is presumed that the annealing step facilitates microcrystallization of the wax around the crystal nuclei formed in the cooling step.

[0113] The conditions for the annealing step can be determined by the annealing temperature and annealing time. The annealing temperature and annealing time are preferably set so that the dispersion is maintained at Ta-35°C to Ta-20°C for 30 minutes or longer. The annealing time is preferably within 150 minutes.

[0114] Furthermore, it is preferable to have an external addition step in which, after extracting the toner particles from the dispersion liquid that has undergone the annealing step, the toner particles are mixed with inorganic fine particles at Ta-35 (°C) to Ta-20 (°C). It is presumed that by externally adding inorganic fine particles to the toner particles within the above temperature range, the uncrystallized wax present near the surface of the toner particles is more likely to form multiple crystal nuclei due to impact from the inorganic fine particles. The present inventors presume that, as a result, minute wax domains are more likely to be formed near the surface of the toner particles.

[0115] The toner produced through the above-mentioned production process is preferred because the above-mentioned R1 and A1 tend to satisfy the above-mentioned preferred ranges.

[0116] That is, the toner manufacturing method is (i) forming particles containing a polymerizable monomer and a wax in an aqueous medium; (ii) polymerizing the polymerizable monomer contained in the particles to form toner particles; (iii) a cooling step of holding the dispersion liquid in which the toner particles are dispersed at Ta+15 (°C) to Ta+35 (°C), where Ta (°C) is the crystallization peak temperature of the wax, and then cooling the dispersion liquid from Ta+15 (°C) to Ta+35 (°C) to Ta-35 (°C) to Ta-20 (°C) at a cooling rate of 40.0 to 200.0°C / min; (iv) an annealing step of holding the dispersion obtained in the step (iii) at Ta-35 (°C) to Ta-20 (°C) for 30 minutes or more; (v) obtaining the toner particles from the dispersion liquid that has been subjected to the step (iv); and (vi) The toner manufacturing method preferably includes an external addition step of externally adding inorganic fine particles to the toner particles at Ta-35 (° C.) to Ta-20 (° C.).

[0117] When a plurality of types of wax are contained in the toner particles, the value of Ta is the crystallization peak temperature of the wax that is contained in the toner particles at the largest ratio.

[0118] <Various measurement methods, etc.> Various measurement methods will be described below.

[0119] <Method for measuring the area ratio of wax domains in a specific region of a cross section of a toner particle> (1) Observation of toner cross section using STEM To observe crystalline materials such as wax inside toner particles, slices of the toner are prepared, stained with ruthenium tetroxide, and then observed using STEM. Staining with ruthenium tetroxide creates a contrast difference between amorphous resins such as binder resins and crystalline materials such as wax during STEM observation. This makes it easier to distinguish and observe crystalline materials such as wax.

[0120] First, toner is dispersed in a visible light curable resin (product name: Aronix LCR Series D-800, manufactured by Toagosei Co., Ltd.), and then cured by irradiation with short wavelength light. The resulting cured product is cut using an ultramicrotome equipped with a diamond knife to prepare 250 nm thin flake samples.

[0121] Next, the cut sample is magnified at a magnification of 40,000 to 50,000 times using a transmission electron microscope (product name: electron microscope JEM-2800, manufactured by JEOL Ltd.) (TEM-EDX) to obtain a cross-sectional image of the toner particle.

[0122] The toner to be observed is selected as follows.

[0123] First, the cross-sectional area of ​​the toner particle is calculated from the image of the toner particle cross section, and the diameter of a circle having the same area as that cross-sectional area (equivalent circle diameter) is calculated. Only the cross-sectional images of toner particles where the absolute value of the difference between this equivalent circle diameter and the weight average particle diameter (D4) of the toner is within 1.0 μm are observed.

[0124] (2) Binarization using image analysis software The wax domain portion of the TEM image is binarized using image analysis software. In this disclosure, binarization was performed using the image analysis software ImageJ. The binarization conditions are appropriately selected depending on the observation conditions, etc. ImageJ is image analysis software available from "https: / / imagej.nih.gov / ij / ".

[0125] As an example of measuring the wax domain area ratio in a specific region in cross-sectional observation of a toner particle, the measurement of the wax domain area ratio in a region (first region) from the surface of the toner particle to a depth of 600 nm inside will be described below.

[0126] Reopen the TEM image before binarization using ImageJ, select [Process] - [Find Edge], and extract the toner contour. Select [centroid] from [Analyze] - [Set Measurements], then select [Analyze] - [Analyze Particles] to find the toner's center of gravity and calculate the length from this center of gravity to any toner contour. Select [Image] - [Scale] to scale the image so that the length to this contour is 600 nm shorter. Overlay the scaled image with the initial image of the wax domain binarized, and mask the area 600 nm or more from the surface of the toner particle.

[0127] (3) Method for measuring the area ratio R1 of wax domains with major axes of 10 to 120 nm and the area ratio R2 of wax domains in the region from the surface of a toner particle to 600 nm: After completing the binarization operation described above, in Image J, select [Analyze] - [Set Measurements] - [Feret's Diameter] and [Area], then select [Analyze] - [Analyze Particles] to obtain the area and major axes of all wax domains and calculate the total area of ​​domains with major axes of 10 nm to 120 nm. Also, using the toner outline extracted images before and after reduction, the entire region within 600 nm from the toner surface is binarized. The area of ​​the region from the surface of a toner particle to 600 nm is obtained by selecting [Analyze] - [Analyze Particles] to obtain the area ratio of wax domains with major axes of 10 nm to 120 nm and the area ratio of all wax domains.

[0128] The above operation is performed on STEM cross-sectional images of 10 toner particles. The average occupied area ratio of wax domains with a major axis of 10 nm or more and 120 nm or less in the region from the surface of the toner particle to 600 nm is designated as R1, and similarly, the average occupied area ratio of all wax domains in that region is designated as R2. Furthermore, the standard deviation and number average A1 of the major axes of all wax domains can be calculated from the major axes of all wax domains calculated above. As above, the standard deviation and number average A1 are the averages of the values ​​calculated for each of the STEM cross-sectional images of 10 toner particles.

[0129] A2 and A3 according to the present disclosure can also be calculated in the same manner as above.

[0130] When a wax domain 4 in FIG. 1 crosses over a contour line 3 obtained by shrinking the contour line 2 of the cross section of the toner particle in the direction of the center of gravity by a distance of 600 nm inward, the wax domain 4 is calculated as belonging to the area with the largest occupied area.

[0131] <Method for measuring weight average particle diameter (D4) of toner and toner particles> The weight average particle diameter (D4) of the toner is measured as follows.

[0132] The measurement device used is the "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.), a precision particle size distribution measurement device using the pore electrical resistance method with a 100 μm aperture tube. The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.). The measurement is performed with an effective number of measurement channels of 25,000.

[0133] The aqueous electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter).

[0134] Before performing measurements and analysis, the dedicated software is set up as follows.

[0135] In the "Change Standard Measurement Method (SOM)" screen of the dedicated software, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particles 10.0 μm" (Beckman Coulter). 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."

[0136] On the "Pulse to particle size conversion setting" 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.

[0137] The specific measurement method is as follows.

[0138] (1) Pour 200 mL of 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 Tube Flush" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube.

[0139] (2) 30 mL of the electrolyte solution is placed in a 100 mL flat-bottom glass beaker. 0.3 mL of a solution prepared by diluting "Contaminon N" (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) three times by mass with ion-exchanged water is added as a dispersant.

[0140] (3) Prepare an ultrasonic disperser "Ultrasonic Dispersion System Tetora150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W and two built-in oscillators with an oscillation frequency of 50 kHz and a phase difference of 180 degrees. Place 3.3 L of ion-exchanged water in the ultrasonic disperser's water tank and add 2 mL of Contaminon N to this water tank.

[0141] (4) Place the beaker (2) into the beaker fixing hole of the ultrasonic disperser, operate the ultrasonic disperser, and adjust the height of the beaker so that the resonance state of the electrolyte solution surface in the beaker is maximized.

[0142] (5) While ultrasonic waves are irradiated to the electrolyte solution in the beaker in (4) above, 10 mg of toner particles are added little by little to the electrolyte solution and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted so that it is between 10°C and 40°C.

[0143] (6) Using a pipette, the electrolytic solution (5) in which the toner particles have been dispersed is dropped into the round-bottom beaker (1) placed in the sample stand, and the measurement concentration is adjusted to 5%. Then, measurements are continued until the number of particles measured reaches 50,000.

[0144] (7) The measurement data is analyzed using the dedicated software that comes with the device, and the weight-average particle diameter (D4) is calculated. 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 diameter (D4) of the toner.

[0145] The weight average particle diameter (D4) of the toner particles is also measured in the same manner as above.

[0146] <Dispersion degree of inorganic fine particles on the surface of toner particles> The degree of dispersion of inorganic particles on the surface of toner particles was calculated using a scanning electron microscope "S-4800 (manufactured by Hitachi High-Technologies Corporation)." Toner particles with inorganic particles externally added to them were observed in the same field of view at a magnification of 10,000 times, with an accelerating voltage of 1.0 kV. From the observed images, the following calculations were made using the image processing software "ImageJ."

[0147] The data was binarized to extract only the inorganic fine particles, and the number n of inorganic fine particles and the coordinates of the center of gravity for all inorganic fine particles were calculated, and the distance dn min between each inorganic fine particle and the nearest external additive was calculated. If the average value of the nearest distance between each inorganic fine particle in one toner particle is dave, the dispersity is expressed by the following formula.

[0148]

number

[0149] The dispersion degree of 50 toner particles randomly observed was determined by the above procedure, and the average value was taken as the dispersion degree of the inorganic fine particles on the surface of the toner particles.

[0150] <Method for measuring coverage X of inorganic fine particles (X) on the surface of toner particles> The coverage ratio X is calculated by analyzing the toner surface image taken with the above-mentioned scanning electron microscope "S-4800" using the above-mentioned image analysis software ImageJ. The details of the calculation are shown below.

[0151] (1) Sample preparation Apply a thin layer of conductive paste to a sample stage (aluminum sample stage 15 mm x 6 mm), then spray toner onto it. Then, use air to remove excess toner from the sample stage and allow it to dry thoroughly. Place the sample stage in the sample holder and adjust the sample stage height to 36 mm using the sample height gauge.

[0152] (2) S-4800 observation condition setting The coverage ratio is calculated using the image obtained by backscattered electron image observation using the S-4800. When measuring the coverage ratio, elemental analysis is first performed using an energy dispersive X-ray analyzer (EDAX) to exclude particles other than inorganic fine particles (such as resin particles) on the toner surface.

[0153] Pour liquid nitrogen into the anti-contamination trap attached to the S-4800 housing until it overflows and leave it for 30 minutes. Start the S-4800's "PC-SEM" and perform flushing (cleaning the FE chip, which is the electron source). Click the accelerating voltage display area on the control panel on the screen and press the [Flushing] button to open the flushing execution dialog. Confirm that the flushing intensity is 2 and execute it. Confirm that the emission current due to flushing is 20-40 μA. Insert the sample holder into the sample chamber of the S-4800 housing. Press [Origin] on the control panel to move the sample holder to the observation position.

[0154] Click the accelerating voltage display to open the HV setting dialog, and set the accelerating voltage to [1.1 kV] and the emission current to [20 μA]. In the [Basic] tab of the operation panel, set the signal selection to [SE], select [Upper (U)] and [+BSE] for the SE detector, and select [LA100] in the selection box to the right of [+BSE] to set the mode for observation using backscattered electron images. Also in the [Basic] tab of the operation panel, set the probe current in the electron optical system condition block to [Normal], the focus mode to [UHR], and the WD to [4.5 mm]. Press the [ON] button in the accelerating voltage display on the control panel to apply the accelerating voltage.

[0155] (3) Focus adjustment Rotate the focus knob [COARSE] on the operation panel until the image is in focus to some extent, then adjust the aperture alignment. Click [Align] on the control panel to display the alignment dialog and select [Beam]. Rotate the STIGMA / ALIGNMENT knobs (X, Y) on the operation panel to move the displayed beam to the center of the concentric circles. Next, select [Aperture] and rotate the STIGMA / ALIGNMENT knobs (X, Y) one by one to stop the image movement or minimize its movement. Close the aperture dialog and use autofocus to adjust the focus. Then, set the magnification to 50,000 (50k)x and adjust the focus using the focus knob and STIGMA / ALIGNMENT knob as above, then use autofocus to adjust the focus again. Repeat this process to adjust the focus. Here, if the tilt angle of the observation surface is large, the accuracy of measuring the coverage rate tends to be low, so when adjusting the focus, select an object that can simultaneously bring the entire observation surface into focus, and then select an object with as little surface tilt as possible for analysis.

[0156] (4) Save image Adjust the brightness in ABC mode, take a photo at a size of 640 x 480 pixels, and save it. Use this image file for the following analysis. Take one photo for each toner particle, obtaining images of 25 toner particles.

[0157] (5) Image analysis In this disclosure, the image obtained by the above-mentioned method is binarized using the following analysis software to calculate the coverage. At this time, the above screen is divided into 12 squares and each is analyzed. The analysis conditions for the image analysis software ImageJ are as follows:

[0158] The coverage rate X is calculated within the square region divided in the above operation, with the area (C) of the region being 24,000 to 26,000 pixels.

[0159] In Image-J, select [Analyze]-[Set Measurements], then select [Feret's Diameter] and [Area], then select [Analyze]-[Analyze Particles] to determine the total area of ​​inorganic particles and the long diameter of the primary particles, and calculate the total area of ​​inorganic particles with a long diameter of primary particles between 60 nm and 300 nm. This image analysis also allows the long diameter of the primary particles of inorganic particles to be measured.

[0160] The coverage rate can be calculated using the following formula from the area C of the square region and the total area D of the region where inorganic fine particles with a major axis of primary particles of 60 nm to 300 nm exist.

[0161] Coverage rate (%)=D / C×100 The average value of all the data obtained is taken as the coverage rate X.

[0162] <Method for measuring the glass transition temperature, crystallization peak temperature, and melting point of a sample> The glass transition temperature of the sample is measured using a differential scanning calorimeter "Q2000 (manufactured by TA Instruments)" in accordance with ASTM D3418-82.

[0163] The melting points of indium and zinc are used to correct the temperature of the detector, and the heat of fusion of indium is used to correct the amount of heat.

[0164] Specifically, 2 mg of a sample is precisely weighed and placed in an aluminum pan, and an empty aluminum pan is used as a reference.

[0165] The measurement temperature range is -10°C to 200°C, and the measurement is performed at a temperature increase rate of 10°C / min. In the measurement, the temperature is first increased from -10°C to 200°C at a rate of 10°C / min, and then decreased from 200°C to -10°C at a rate of 10°C / min.

[0166] Thereafter, the temperature is increased again from -10°C to 200°C at a rate of 10°C / min.

[0167] The crystallization peak temperature is obtained from the DSC curve in the temperature range from 200°C to -10°C during the first cooling.

[0168] In the DSC curve during the first cooling, the temperatures before and after the specific heat change appear are used as baselines, and the temperature at which the peak height is greatest is taken as the crystallization peak temperature of the sample.

[0169] The glass transition temperature is obtained from the DSC curve in the temperature range of 20°C to 100°C during the second heating.

[0170] The temperature (°C) at the intersection of the DSC curve and the line midway between the baselines before and after the specific heat change is taken as the glass transition temperature of the sample. The temperature at which the highest peak is observed in the DSC curve during the second heating is taken as the melting point of the sample. [Example]

[0171] The present disclosure will be described in more detail below with reference to examples and comparative examples, but the present disclosure is not limited thereto. Parts used in the examples are by weight unless otherwise specified.

[0172] (Example of wax 1 production) Stearic acid 100.0 parts by mass Behenyl alcohol 252.0 parts by mass p-Toluenesulfonic acid 0.50 parts by mass The above materials were added under reflux, and the esterification reaction was allowed to proceed for 6 hours at 120°C. During this time, the water produced was removed from the system by toluene / water azeotropy. After the reaction was completed, p-toluenesulfonic acid was neutralized with sodium bicarbonate. The toluene was distilled off from the resulting solution to obtain the product. The product was heated to 90°C and then filtered through Celite to remove sodium p-toluenesulfonate, yielding Wax 1. The physical properties of the resulting Wax 1 are shown in Table 1.

[0173] (Production Examples of Wax 2 and Wax 4) Wax 2 and Wax 4 were obtained in the same manner as in Production Example of Wax 1, except that the types and amounts of acid monomers and alcohol monomers used were changed as shown in Table 1. The physical properties of Wax 2 and Wax 4 are shown in Table 1.

[0174] The physical properties of Wax 3 and Wax 5 are shown in Table 1.

[0175] [Table 1]

[0176] <Production Example of Inorganic Fine Particles 1> A 3-liter glass reactor equipped with a stirrer, dropping funnel, and thermometer was charged with 589.6 parts of methanol, 42.0 parts of water, and 47.1 parts of 28% by weight aqueous ammonia, and mixed. The resulting solution was adjusted to 35°C, and while stirring, 1100.0 parts of tetramethoxysilane and 395.2 parts of 5.4% by weight aqueous ammonia were simultaneously added. Tetramethoxysilane was added dropwise over 6 hours, and aqueous ammonia over 5 hours. After the dropwise addition was completed, stirring was continued for an additional 0.5 hours to allow hydrolysis, resulting in a methanol-water dispersion of hydrophilic spherical sol-gel silica microparticles. Next, an ester adapter and a cooling tube were attached to the glass reactor, and the dispersion was thoroughly dried at 80°C under reduced pressure to obtain inorganic microparticle raw material. The above process was repeated several times, and the resulting inorganic microparticle raw material was then crushed using a pulverizer (manufactured by Hosokawa Micron Corporation).

[0177] Then, 500 parts of the crushed inorganic fine particle raw material was placed in a polytetrafluoroethylene inner cylinder stainless steel autoclave. After replacing the atmosphere in the autoclave with nitrogen gas, 0.5 parts of HMDS (hexamethyldisilazane) and 0.1 parts of water were atomized using a two-fluid nozzle and sprayed uniformly onto the silica powder while rotating the stirring blade attached to the autoclave at 400 rpm. After stirring for 30 minutes, the autoclave was sealed and heated at 200°C for 2 hours. Subsequently, the system was depressurized while still heated to remove ammonia, yielding inorganic fine particles 1. The physical properties of the obtained inorganic fine particles 1 are shown in Table 2.

[0178] <Production Examples of Inorganic Fine Particles 2 to 5> Inorganic fine particles 2 to 5 were obtained in the same manner as in the production example of inorganic fine particles 1, except that the amount of methanol used, the dropwise addition time of tetramethoxysilane, and the dropwise addition time of 5.4 mass% ammonia water were changed as shown in Table 2. In the surface treatment with HMDS, the amounts of HMDS and water were adjusted so that the carbon amount was the same as that of inorganic fine particles 1. The physical properties of the obtained inorganic fine particles 2 to 5 are shown in Table 2.

[0179] <Production Example of Inorganic Fine Particles 6> As inorganic fine particles 6, dry silica fine particles (hydrophobic treatment by HMDS, BET specific surface area: 200 m 2 The physical properties of inorganic fine particles 6 are shown in Table 2.

[0180] [Table 2]

[0181] <Production Example of Toner Particle 1> The following materials were mixed using an attritor (Nippon Coke and Engineering Co., Ltd.), and the mixture was stirred for 2 hours to dissolve the materials, thereby obtaining a monomer composition. Styrene 36.0 parts by mass n-Butyl acrylate 28.0 parts by mass Charge control agent Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) 1.0 parts by mass 3.0 parts by mass of amorphous polyester (saturated polyester obtained by condensation polymerization of 2 moles of ethylene oxide adduct of bisphenol A and terephthalic acid (number average molecular weight = 5000, acid value = 6 mg KOH / g, glass transition temperature = 68 ° C)) The following materials were mixed and stirred in an attritor (manufactured by Nippon Coke and Engineering Co., Ltd.) together with zirconia beads (3 / 16 inch) at 1.7 m / s for 3 hours, and the beads were separated to obtain a colorant dispersion. Styrene 36.0 parts by mass ·Colorant (CIPigment Blue 15:3 (manufactured by Dainichiseika)) 6.0 parts by mass Next, the following materials were mixed to obtain a mixture. Monomer composition 75.0 parts by mass Colorant dispersion 42.25 parts by weight The obtained mixture was heated to 60°C, and 20.0 parts by mass of Wax 1 and 10.0 parts by mass of Wax 5 were added. Next, 10.0 parts by mass of a polymerization initiator (2,2'-azobis(2,4-dimethylvaleronitrile)) was added, and the mixture was stirred for 5 minutes to obtain a polymerizable monomer composition.

[0182] Meanwhile, 850 parts by mass of 0.1 mol / L Na3PO4 aqueous solution and 8.0 parts by mass of 10% hydrochloric acid were added to a container equipped with a high-speed stirring device, Clearmix (M Technique), and the rotation speed was adjusted to 33 m / s and heated to 60°C. 68 parts by mass of 1.0 mol / L CaCl2 aqueous solution was added to the mixture to prepare an aqueous medium containing minute amounts of the poorly water-soluble dispersant Ca3(PO4)2.

[0183] Five minutes after adding the polymerization initiator, the polymerizable monomer composition at 60°C was added to the aqueous medium heated to 60°C, and granulation was carried out for 15 minutes while rotating the Clearmix at 33 m / s.

[0184] The mixture was then stirred with a propeller stirrer at 70°C for 5 hours, then heated to 85°C and reacted for an additional 4 hours to produce toner particles. After the polymerization reaction was complete, the suspension was heated to 100°C and held there for 2 hours. Residual monomers were removed under reduced pressure. The suspension was then cooled at a cooling rate of 120°C / min from 95°C (starting temperature) to 45°C (final temperature). After cooling, the suspension was heated to 50°C and held there for 120 minutes to undergo an annealing process. Hydrochloric acid was added after the annealing process to lower the pH to 2.0 or less, dissolving the poorly water-soluble dispersant. After repeated water washing, the mixture was dried in a dryer at 40°C for 72 hours and then classified using a multi-division classifier utilizing the Coanda effect to obtain toner particles 1. The physical properties of toner particles 1 are shown in Table 3.

[0185] <Production Examples of Toner Particles 2 to 18 and Toner Particles 21 and 22> Toner particles 2 to 18, and toner particles 21 and 22 were obtained in the same manner as in the production of toner particles 1, except that the preparation of the aqueous medium, the type of wax, the amount of wax added, the quenching rate in the cooling step, and the temperature in the annealing step were changed as shown in Table 3. The physical properties of the obtained toner particles 2 to 18, and toner particles 21 and 22 are shown in Table 3.

[0186] <Production Example of Toner Particle 19> Binder resin (styrene-n-butyl acrylate copolymer (copolymerization ratio = 79.0:21.0, Tg = 50°C)) 100.0 parts by mass ·Colorant (CIPigment Blue 15:3 (manufactured by Dainichiseika)) 6.0 parts by mass Wax 5 10.0 parts Charge control agent (Bontron E-88, manufactured by Orient Chemical Co., Ltd.) 2.0 parts The above materials were premixed in a Henschel mixer, and then melt-kneaded using a twin-screw kneading extruder (PCM-30 model, manufactured by Ikegai Iron Works Co., Ltd.) to obtain a kneaded mixture.

[0187] The obtained kneaded product was cooled, coarsely pulverized with a hammer mill, and then pulverized with a mechanical pulverizer (T-250 manufactured by Turbo Kogyo Co., Ltd.), and the obtained finely pulverized powder was classified with a multi-division classifier utilizing the Coanda effect to obtain toner particles 19. The physical properties of the obtained toner particles 19 are shown in Table 3.

[0188] <Production Example of Toner Particles 20> (Preparation of Resin Particle Dispersion) The following materials were mixed in a flask to prepare an aqueous medium. Ion-exchanged water 500.0 parts by mass Nonionic surfactant Nonipol 400 (Sanyo Chemical Industries, Ltd.) 6.0 parts by mass Anionic surfactant Neogen SC (Dai-ichi Kogyo Seiyaku) 10.0 parts by mass The following materials were mixed to obtain a mixed solution. Styrene 79.0 parts by mass n-Butyl acrylate 21.0 parts by mass Charge control agent Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) 1.0 parts by mass The above mixed solution was dispersed and emulsified in the above aqueous medium, and while slowly stirring and mixing for 10 minutes, 50 parts by mass of an ion-exchange aqueous solution containing 4.0 parts by mass of ammonium persulfate dissolved therein as a polymerization initiator was added. Next, after thoroughly replacing the atmosphere in the system with nitrogen, the flask was heated in an oil bath with stirring until the temperature inside the system reached 70°C, and the polymerization reaction was carried out for 5 hours. This resulted in an anionic resin microparticle dispersion.

[0189] (Preparation of Colorant Fine Particle Dispersion) The following materials were dispersed for 10 minutes using Ultra Turrax T50 (manufactured by IKA Corporation) to obtain a colorant particle dispersion. Ion-exchanged water 100.0 parts by mass Colorant (CI Pigment Blue 15:3 (manufactured by Dainichi Seika Chemicals Co., Ltd.)) 6.0 parts by mass Nonionic surfactant (Nonipol 400 (manufactured by Sanyo Chemical Industries)) 1.0 parts by mass (Preparation of Wax Microparticle Dispersion) Ion-exchanged water 100.0 parts by mass Wax 5 10.0 parts by mass Cationic surfactant Sanisol B50 (Kao) 5.0 parts by mass The above components were heated to a temperature of 95°C and thoroughly dispersed using an Ultra Turrax T50, and then dispersed using a pressure discharge homogenizer to obtain a wax microparticle dispersion.

[0190] (Preparation of Resin Particle Dispersion) The following materials were mixed and stirred, and then emulsified using Ultra Turrax T50 while being maintained at a temperature of 80° C. for 6 hours to remove the solvent, thereby obtaining a resin particle dispersion liquid. Ion-exchanged water 100.0 parts by mass Ethyl acetate 50.0 parts by mass Resin (styrene / methyl methacrylate / methacrylic acid / 2-hydroxyethyl methacrylate copolymer. Weight average molecular weight: 14,000, number average molecular weight: 6,000, peak top molecular weight: 14,000, glass transition temperature: 92°C, acid value: 20 mgKOH / g, hydroxyl value: 10 mgKOH / g) 10.0 parts by mass (Production of toner particles) The resin particle dispersion, colorant particle dispersion, wax particle dispersion, and 1.2 parts by mass of polyaluminum chloride were mixed and thoroughly mixed and dispersed in a round stainless steel flask using an Ultra-Turrax T50. The flask was then heated to 51°C with stirring in a heating oil bath. After maintaining the temperature at 51°C for 60 minutes, the resin particle dispersion was added. The pH of the system was then adjusted to 6.5 using a 0.5 mol / L aqueous sodium hydroxide solution. The stainless steel flask was then sealed, the stirring shaft was magnetically sealed, and the mixture was heated to 95°C with continued stirring and maintained for 6 hours.

[0191] After the reaction was completed, the mixture was allowed to cool to 20° C., and then filtered, washed, dried and classified to obtain toner particles 20. The physical properties of toner particles 20 are shown in Table 3.

[0192] [Table 3]

[0193] *For toner particles 6 to 9, the weight average particle size of the resulting toner particles was controlled by changing the number of parts of each aqueous solution used when preparing the aqueous medium. The changed number of parts is shown below.

[0194] Toner particles 6: The amount of Na3PO4 aqueous solution was changed to 840 parts, the amount of 10% hydrochloric acid was changed to 8.8 parts, and the amount of CaCl2 aqueous solution was changed to 75 parts.

[0195] Toner particles 7: The amount of Na3PO4 aqueous solution was changed to 865 parts, the amount of 10% hydrochloric acid was changed to 5.5 parts, and the amount of CaCl2 aqueous solution was changed to 47 parts.

[0196] Toner particles 8: The amount of Na3PO4 aqueous solution was changed to 830 parts, the amount of 10% hydrochloric acid was changed to 9.6 parts, and the amount of CaCl2 aqueous solution was changed to 82 parts.

[0197] Toner particles 9: The amount of Na3PO4 aqueous solution was changed to 876 parts, the amount of 10% hydrochloric acid was changed to 3.9 parts, and the amount of CaCl2 aqueous solution was changed to 33 parts.

[0198] <Toner 1 manufacturing example> 100.0 parts of toner particles 1 and 0.5 parts of inorganic fine particles 1 (inorganic fine particles (X)) were added to an FM mixer (FM10C manufactured by Nippon Coke and Engineering Co., Ltd.) in which the treatment blade had been changed from the rotor shown in Fig. 3 to the rotor shown in Fig. 2. Thereafter, a first-stage external addition was carried out by mixing at 2000 rpm for 10 minutes, and toner precursor 1-1 was obtained.

[0199] At this time, at the same time as the start of mixing, hot water and cold water were passed through the jacket as needed to maintain the temperature inside the tank at 45°C.

[0200] Then, in the second external addition step, 100 parts by mass of toner precursor 1-1 and 0.5 parts of inorganic fine particles 6 were placed in an FM mixer (FM10C manufactured by Nippon Coke and Engineering Co., Ltd.) with 7°C water flowing through the jacket. After the water temperature inside the jacket stabilized at 7°C ± 1°C, the mixture was mixed at 3000 rpm for 5 minutes to obtain toner precursor 1-2. During this process, the water flow rate inside the jacket was appropriately adjusted so that the temperature inside the FM mixer tank did not exceed 25°C.

[0201] Toner Precursor 1-2 was sieved through a mesh with 75 μm openings to obtain Toner 1 (cyan toner). The physical properties of Toner 1 are shown in Table 5.

[0202] The rotor shown in Fig. 3 is the rotor that the above-mentioned FM10C has at the time of sale. In Fig. 2 and Fig. 3, 140 and 150 are processing blades, 141 and 151 are the main bodies of the processing blades, and 142 and 152 are processing sections. In each figure, (a) is a top view, and (b) is a side view.

[0203] <Production examples of toners 2 to 37> Toners 2 to 37 were obtained in the same manner as in the production example of Toner 1, except that the type of toner particles, the type and amount of inorganic fine particles (X), whether or not the treatment blade was changed, the conditions for the first-stage external addition, and whether or not the second-stage external addition was performed were changed as shown in Table 4. The physical properties of Toners 2 to 37 are shown in Table 5.

[0204] [Table 4]

[0205] [Table 5]

[0206] The abbreviations in Table 5 are as follows:

[0207] D4: Weight average particle diameter of toner Tg: Glass transition temperature of the toner R1: Area ratio of wax domains with a major axis of 10 to 120 nm in the region from the surface of a toner particle to the inside of 600 nm R2: Area ratio of all wax domains in the region from the surface of the toner particle to the inside of 600 nm Standard deviation: Standard deviation of the major axis of all wax domains in the region from the surface of the toner particle to the inside of 600 nm A1: Number average value of the major axis of all wax domains in the region from the surface of the toner particle to the inside of 600 nm A2: Number average value of the major axis of all wax domains in the region of 600 nm or more and 1500 nm or less from the surface of the toner particle A3: Number average value of the major axis of all wax domains in the region of 1500 nm or more from the surface of the toner particle Coverage rate X: Coverage rate of inorganic fine particles (X) on the surface of toner particles Example 1 Toner 1 was evaluated as follows, and the evaluation results are shown in Table 6.

[0208] <Evaluation of low-temperature fixability of toner> First, the fixing unit was removed from a modified laser printer (product name: HP LaserJet Enterprise M553X, manufactured by HP). The modification of this modified machine was to allow the amount of toner applied to be arbitrarily set, so that an unfixed image could be obtained. The fixing unit removed from the modified machine was also modified so that the temperature of the fixing unit could be arbitrarily set. In addition, white paper (product name: Prober Bond Paper (105 g / m 2), manufactured by Fox River) was left in a room temperature and high humidity environment (temperature 25°C, humidity 80% RH) for 3 days.

[0209] Using the above-mentioned modified machine, the modified fixing unit, and white paper, the low-temperature fixing property of the toner was evaluated. 2 After preparing an unfixed image set at 150°C, the unfixed image was passed through the fixing unit set at 150°C in a room temperature and high humidity environment (temperature 25°C, humidity 80% RH) to obtain a fixed image.

[0210] The image density of the resulting fixed image was measured, and then the fixed image was subjected to pressure of 4.9 kPa (50 g / cm 2 The image was rubbed with Silbon paper under a load of 0.15 kgf / cm², and the image density of the fixed image was measured again. The reduction rate (%) of image density before and after rubbing was calculated, and the low-temperature fixability of the toner was evaluated using this value. The results are shown in Table 6. An image density reduction rate of less than 20.0% was determined to be one in which the effects of the present disclosure were obtained. The image density was measured using a Macbeth densitometer (manufactured by Macbeth Co., Ltd.), which is a reflection densitometer, and an SPI filter.

[0211] <Evaluation of image density in high temperature and humidity environments> A modified laser printer (product name: HP LaserJet Enterprise M553X, manufactured by HP) and white paper (product name: PB PAPER, manufactured by Canon Marketing Japan, basis weight 66 g / cm 2 The image density was evaluated when an image was output in a high temperature and high humidity environment using a modified printer (letter). The modification to the modified machine was to change the process speed to 400 mm / s.

[0212] First, the toner inside the cartridge was removed and emptied, and then 300 g of Toner 1 was filled into the cartridge.

[0213] The horizontal line pattern with a print rate of 1.5% was printed on two sheets per job, and the machine was set to a mode in which it would stop between jobs before starting the next job. 5,000 images were printed in a high-temperature, high-humidity environment (temperature 32.5°C, humidity 85%RH).

[0214] After outputting the 5,000 images described above, one image was output with a 5 mm x 5 mm solid black image in three locations (left, right, and center) with a 5 mm margin at the top and 5 mm margins on both sides, and three locations in the longitudinal direction spaced 30 mm apart, for a total of nine locations.

[0215] The image density of nine solid black images in the image was measured, and the average value was used to evaluate the image density when the image was output in a high-temperature, high-humidity environment. The results are shown in Table 6. The image density was measured using a Macbeth densitometer (manufactured by Macbeth Co.), which is a reflection densitometer, and an SPI filter. An image density of 1.20 or higher in the measurement was determined to be good.

[0216] <Evaluation of image defects in high temperature and humidity environments> Using the modified machine and white paper used in the evaluation of image density in the high-temperature, high-humidity environment, image defects when images were output in a high-temperature, high-humidity environment were evaluated.

[0217] A horizontal line pattern with a print rate of 1.5% was printed on two sheets per job, and the machine was set to a mode in which it would stop between jobs before the next job began, and 5,000 images were output in a high-temperature, high-humidity environment (temperature 32.5°C, humidity 85% RH).

[0218] Before and after the above-mentioned 5,000 image output, a full-surface solid image was output with a 5 mm leading edge margin and 5 mm left and right margins, and the developing bias was adjusted so that the image density of both sides of the solid image was 1.50 to 1.55 on a Macbeth densitometer. Then, with the adjusted bias setting, one image having 100 dots with a diameter of 180 μm was output. The number of dots that had image defects among the 100 dots in the image was visually confirmed, and the number was used to evaluate image defects under a high-humidity environment. When the number of dots with image defects was 20 or less, it was determined that the effects of the present disclosure had been achieved.

[0219] <Examples 2 to 31 and Comparative Examples 1 to 6> Toners 1 to 37 were evaluated in the same manner as above, except that Toner 1 was replaced with a toner shown in Table 6. The evaluation results are shown in Table 6.

[0220] [Table 6] [Explanation of symbols]

[0221] 1 Tiny wax domains 2. Surface contours of toner particles 3. Contour line reduced by a distance of 600 nm from the surface of a toner particle 4 Wax domain spanning the contour line shrunk by a distance of 600 nm from the surface of the toner particle 5 Coarse wax domains 6 Inorganic fine particles 140 Processing blade 141 Processing blade body 142 Processing section 150 Processing blade 151 Processing blade body 152 Processing section

Claims

1. A toner comprising toner particles containing a resin component and a wax, and inorganic fine particles on the surfaces of the toner particles, In the cross-sectional observation of the toner particle, domains comprising said wax are observed; a region extending from the surface of the toner particle to a depth of 600 nm inside the toner particle is defined as a first region; R1 (%) represents the occupied area ratio of the domains having a major axis of 10 to 120 nm in the first region, When the occupied area ratio of all the domains in the first region is R2 (%), The R1 (%) and the R2 (%) satisfy the following formula (1) and formula (2), 2.0 ≦ R1 (%) ≦ 15.0 ... Formula (1) R1 (%) / R2 (%) ≧ 0.60... Formula (2) The wax is an ester wax. A toner characterized by:

2. A toner comprising toner particles containing a resin component and a wax, and inorganic fine particles on the surfaces of the toner particles, In the cross-sectional observation of the toner particle, domains comprising said wax are observed; a region extending from the surface of the toner particle to a depth of 600 nm inside the toner particle is defined as a first region; R1 (%) represents the occupied area ratio of the domains having a major axis of 10 to 120 nm in the first region, When the occupied area ratio of all the domains in the first region is R2 (%), The R1 (%) and the R2 (%) satisfy the following formula (1) and formula (2), 2.0 ≦ R1 (%) ≦ 15.0 ... Formula (1) R1 (%) / R2 (%) ≧ 0.60... Formula (2) The resin component contains a styrene-acrylic resin, The content of the styrene-acrylic resin in the resin component is 80.0 to 100.0 mass %. A toner characterized by:

3. In the cross-sectional observation of the toner particle, The standard deviation of the major axes of all the domains in the first region is 40 nm or less. The toner according to claim 1 or 2.

4. In the cross-sectional observation of the toner particle, A1 is the number average value of the major axes of all the domains in the first region, a region of 600 nm or more and 1500 nm or less from the surface of the toner particle is defined as a second region; When the number average value of the major axes of all the domains in the second region is A2, The A1 and A2 satisfy the following formula (3): A2-A1 ≧ 30nm... Formula (3) The toner according to any one of claims 1 to 3.

5. In the cross-sectional observation of the toner particle, When the number average value of the major axes of all the domains in the first region is A1, The A1 is 50 to 200 nm. The toner according to any one of claims 1 to 4.

6. In the cross-sectional observation of the toner particle, a region of 600 nm or more and 1500 nm or less from the surface of the toner particle is defined as a second region; When the number average value of the major axes of all the domains in the second region is A2, The A2 is 110 to 210 nm. The toner according to any one of claims 1 to 5.

7. In the cross-sectional observation of the toner particle, A1 is the number average value of the major axes of all the domains in the first region, a region of 600 nm or more and 1500 nm or less from the surface of the toner particle is defined as a second region; A2 is the number average value of the major axes of all the domains in the second region, a region of 1500 nm or more from the surface of the toner particle is defined as a third region; When the number average value of the major axes of all the domains in the third region is A3, The A1, A2, and A3 satisfy the following formula (4) and formula (5): A1 < A2 < A3... Formula (4) 800nm≦A3... Formula (5) The toner according to any one of claims 1 to 6.

8. 8. The toner according to claim 1, wherein the weight average particle diameter (D4) of the toner is 5.0 to 10.0 μm.

9. 9. The toner according to claim 1, wherein the dispersion degree of the inorganic fine particles on the surface of the toner particles is 2.0 nm or less.

10. 10. The toner according to claim 1, wherein the wax contains a hydrocarbon wax.

11. the inorganic fine particles contain inorganic fine particles (X) having a major axis of primary particles of 60 to 300 nm, When the coverage of the inorganic fine particles (X) on the surface of the toner particles is X (%), The R2 (%) and the X (%) satisfy the following formula (6): X≦R2... Formula (6) The toner according to any one of claims 1 to 10.

12. A method for producing a toner, comprising: The manufacturing method comprises: (i) forming particles containing a polymerizable monomer and a wax in an aqueous medium; (ii) polymerizing the polymerizable monomer contained in the particles to form toner particles; (iii) a cooling step of holding the dispersion liquid in which the toner particles are dispersed at Ta+15 (°C) to Ta+35 (°C), where Ta (°C) is the crystallization peak temperature of the wax, and then cooling the dispersion liquid from Ta+15 (°C) to Ta+35 (°C) to Ta-35 (°C) to Ta-20 (°C) at a cooling rate of 40.0 to 200.0°C / min; (iv) an annealing step of holding the dispersion obtained in the step (iii) at Ta-35 (°C) to Ta-20 (°C) for 30 minutes or more; (v) removing the toner particles from the dispersion liquid that has been subjected to the step (iv); and (vi) adding inorganic fine particles to the toner particles at Ta-35 (°C) to Ta-20 (°C); A toner manufacturing method comprising:

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