Toner

Abstract

To provide toner that achieves excellent low temperature fixability, heat-resistant storage properties, and hot offset resistance, and is excellent in gloss uniformity on rough paper.SOLUTION: Toner has a toner particle containing a binder resin. The binder resin contains a crystalline resin A. The crystalline resin A contains a monomer unit (a) having a specific structure. In viscoelasticity measurement of the toner, when a temperature at which a storage modulus G' of the toner becomes 1.0×107 Pa is defined as T1(°C), a ratio (tanδ) of a loss modulus G" of the toner to the storage modulus G' of the toner at the temperature T1(°C) as tanδ(T1), and tanδ at a temperature T1-10(°C) as tanδ(T1-10), the T1, the tanδ(T1), and the tanδ(T1-10) satisfy specific relationships. The toner particle contains a straight-chain fatty acid metal salt including di- or more-valent metal.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to toners used in electrophotography and electrostatic recording. [Background technology]

[0002] Energy saving is also considered a major technical issue in electrophotographic devices, and significant reductions in the energy required for fixing devices are being considered. For toner, technology to improve so-called "low-temperature fixing property" that enables fixing with lower energy is being considered.

[0003] As a method to enable fixing at low temperatures, a technology using crystalline resin as the binder resin of the toner is being considered. Crystalline resins have the property that they hardly soften at temperatures lower than their melting point because their molecular chains are regularly arranged. On the other hand, when the melting point is exceeded, the crystals melt suddenly, which is accompanied by a rapid drop in viscosity. For this reason, crystalline resins are attracting attention as materials that have excellent sharp melting properties and low-temperature fixing properties.

[0004] Usually, crystalline vinyl resins have long-chain alkyl groups as side chains, and the long-chain alkyl groups in the side chains are oriented to each other to exhibit crystallinity. Patent Document 1 discloses a toner using a crystalline vinyl resin, which is a copolymer of a polymerizable monomer having a long-chain alkyl group and an amorphous polymerizable monomer having a different SP value, as a toner using a crystalline vinyl resin. Furthermore, Patent Document 2 discloses a toner in which a polymerizable crosslinking agent is added or increased in amount, and a gel component exhibiting high elasticity is increased in order to suppress deterioration in hot offset resistance and heat-resistant storage stability that accompanies the addition of a crystalline resin to improve low-temperature fixing ability. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-173414 A [Patent Document 2] JP 2018-151619 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the toner of Patent Document 1, if the amount of the crystalline resin component is increased in order to obtain even better low-temperature fixing performance, problems arise such as the occurrence of hot offset due to the low elasticity of the crystalline resin when melted, and the uniformity of gloss on rough paper with large irregularities. In addition, in the toner of Patent Document 2, when the degree of crosslinking of the gel is increased, the compatibility between the other binder resin components with low elasticity and the gel components with high elasticity decreases. As a result, the other low-viscosity components are separated, and the effects of suppressing hot offset and improving gloss uniformity on rough paper are limited. There is also a problem that low-temperature fixability is impaired.

[0007] The present disclosure provides a toner that achieves excellent low-temperature fixing property, heat-resistant storage stability, and hot offset resistance, and further has excellent gloss uniformity on rough paper. [Means for solving the problem]

[0008] The present disclosure relates to a toner having toner particles containing a binder resin, The binder resin contains a crystalline resin A, (i) the crystalline resin A contains a monomer unit (a) represented by the following formula (1), TIFF2024001651000001.tif43170 (in formula (1), R 1 represents a hydrogen atom or a methyl group, L 1 represents a single bond, an ester bond or an amide bond, and m is an integer of 15 to 30. (ii) the content of the monomer unit (a) in the crystalline resin A is 30.0% by mass or more, (iii) the monomer unit (a) contains an alkyl group having a carbon number C(a) of 16 to 31; (iv) the content of the crystalline resin A in the toner is 20.0 to 90.0% by mass, In the viscoelasticity measurement of the toner, the storage modulus G' of the toner is 1.0×10 7 The temperature at which Pa is reached is T1 [℃]. The ratio (tan δ) of the loss elastic modulus G″ of the toner to the storage elastic modulus G′ of the toner at a temperature T1 [° C.] is defined as tan δ(T1), When tan δ at temperature T1-10 [℃] is tan δ(T1-10), The T1, the tan δ(T1), and the tan δ(T1-10) satisfy the following formulas (2) to (4), 50.0≦T1≦70.0 (2) 0.3≦tan δ(T1)≦1.0 (3) 1.0≦tanδ(T1) / tanδ(T1-10)≦1.9 (4) The toner particles are Contains a metal salt of a straight chain fatty acid, the number of carbon atoms C(a) of the alkyl group and the number of carbon atoms C(b) of the straight-chain fatty acid of the straight-chain fatty acid metal salt are |C(a)-C(b)|≦10 is satisfied, The toner is characterized in that the valence of the metal in the straight-chain fatty acid metal salt is divalent or greater. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a toner that has excellent low-temperature fixing property, heat-resistant storage stability, and hot offset resistance, and further has excellent gloss uniformity on rough paper. [Brief description of the drawings]

[0010] [Figure 1] Example of sample attachment for viscoelasticity measurement DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In the present disclosure, the description of a numerical range such as "XX or more and YY or less" or "XX to YY" means a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. The (meth)acrylic acid ester means an acrylic acid ester and / or a methacrylic acid ester.

[0012] The term "monomer unit" refers to the reacted form of a monomer substance in a polymer. For example, one section of carbon-carbon bond in the main chain of a polymer in which a vinyl monomer is polymerized is considered to be one unit. A vinyl monomer can be represented by the following formula (6). TIFF2024001651000002.tif33170

[0013] [In formula (6), R A represents a hydrogen atom or an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group); R B represents an optional substituent.] In the present disclosure, a crystalline resin refers to a resin that shows a clear endothermic peak in a differential scanning calorimeter (DSC) measurement.

[0014] The inventors of the present invention have conducted research to solve the problem. The process of fixing toner to paper can be roughly divided into three steps. Specifically, it can be divided into (1) a step in which the toner melts and penetrates into the paper, (2) a step in which the toner is separated from the fixing member, and (3) a step in which the toner is cooled, solidified, and fixed on the paper.

[0015] The three processes above require different properties for the toner. In the step (1), the toner is required to have a low melt viscosity. A low melt viscosity makes it easier for the toner to penetrate into the paper, so there is no need to apply excessive heat to melt the toner, and it can exhibit excellent low-temperature fixing properties.

[0016] On the other hand, in the step (2), the melting viscosity of the toner is required to be high. If the melting viscosity is low, the melted toner will remain attached to the paper or fixing member, which will easily cause hot offset.

[0017] In the step (3), the melt viscosity of the toner needs to be appropriately low. If the melt viscosity is too high, the melted toner cannot be sufficiently leveled, and the gloss of the fixed image tends to be uneven. However, if the melt viscosity is too low, the gloss tends to be uneven on rough paper with large irregularities.

[0018] As described above, the toner characteristics required in steps (1) and (2) are contradictory. Furthermore, when trying to satisfy the characteristics required in step (3), it became apparent that there was a limit to the low-temperature fixing property, hot offset resistance, and gloss uniformity on rough paper that could be achieved by polymer design as in conventional technology.

[0019] In order to solve the above problems, the present inventors have investigated a technique capable of achieving the above-mentioned contradictory toner physical properties, based on a mechanism different from that of conventional polymer design. Specifically, since the toner is softened by the application of heat and pressure in the fixing process, it was thought that the problem could be solved by utilizing this to control the molecular state in the toner. The form for achieving this is explained below.

[0020] The present inventors have discovered that by controlling the molecular state in the toner as described below, it is possible to provide a toner that has excellent low-temperature fixing properties, heat-resistant storage stability, and hot offset resistance, and further has excellent gloss uniformity on rough paper. A toner having toner particles containing a binder resin, The binder resin contains a crystalline resin A, (i) the crystalline resin A contains a monomer unit (a) represented by the following formula (1), TIFF2024001651000003.tif43170 (in formula (1), R 1 represents a hydrogen atom or a methyl group, L 1represents a single bond, an ester bond or an amide bond, and m is an integer of 15 to 30. (ii) the content of the monomer unit (a) in the crystalline resin A is 30.0% by mass or more, (iii) the monomer unit (a) contains an alkyl group having a carbon number C(a) of 16 to 31; (iv) the content of the crystalline resin A in the toner is 20.0 to 90.0% by mass, In the viscoelasticity measurement of the toner, the storage modulus G' of the toner is 1.0×10 7 The temperature at which Pa is reached is T1 [℃]. The ratio (tan δ) of the loss elastic modulus G″ of the toner to the storage elastic modulus G′ of the toner at a temperature T1 [° C.] is defined as tan δ(T1), When tan δ at temperature T1-10 [℃] is tan δ(T1-10), The T1, the tan δ(T1), and the tan δ(T1-10) satisfy the following formulas (2) to (4), 50.0≦T1≦70.0 (2) 0.3≦tan δ(T1)≦1.0 (3) 1.0≦tanδ(T1) / tanδ(T1-10)≦1.9 (4) The toner particles are Contains a metal salt of a straight chain fatty acid, the number of carbon atoms C(a) of the alkyl group and the number of carbon atoms C(b) of the straight-chain fatty acid of the straight-chain fatty acid metal salt are |C(a)-C(b)|≦10 is satisfied, The toner is characterized in that the valence of the metal in the straight-chain fatty acid metal salt is divalent or greater.

[0021] In order to ensure low-temperature fixability while maintaining heat-resistant storage stability, it is necessary for the storage modulus to be high up to a temperature required for heat-resistant storage stability, and for the storage modulus to drop sharply when the temperature is raised above that temperature, i.e., for the toner to exhibit sharp melt properties. As mentioned above, a crystalline resin is an example of a material that exhibits sharp melt properties.

[0022] The toner of the present disclosure has toner particles containing a binder resin. The binder resin contains a crystalline resin A. The crystalline resin A contains a monomer unit (a) represented by the following formula (1). TIFF2024001651000004.tif43170 (in formula (1), R 1 represents a hydrogen atom or a methyl group, L 1 represents a single bond, an ester bond or an amide bond, and m represents an integer of 15 to 30. L 1 is preferably an ester bond, and more preferably the carbonyl in the ester bond -COO- is R 1 is bonded to the carbon having

[0023] The content of the monomer unit (a) in the crystalline resin A is 30.0% by mass or more. When the crystalline resin A contains 30.0% by mass or more of the monomer unit (a), the side chains are oriented and the crystalline resin A can exhibit crystallinity. As a result, the low-temperature fixability is improved.

[0024] The content of the monomer unit (a) in the crystalline resin A is preferably 50.0% by mass or more, since the resin is more likely to exhibit crystallinity. It is more preferably 60.0% by mass or more, and particularly preferably 70.0% by mass or more. There is no upper limit, but it is preferably 90.0% by mass or less from the viewpoint of heat-resistant storage stability, and more preferably 85.0% by mass or less. For example, preferred values ​​include 50.0 to 90.0% by mass, 60.0 to 90.0% by mass, 70.0 to 90.0% by mass, 60.0 to 85.0% by mass, and 70.0 to 85.0% by mass.

[0025] The monomer unit (a) represented by the formula (1) contains an alkyl group having 16 to 31 carbon atoms, C(a). As described above, a crystalline vinyl resin has long-chain alkyl groups as side chains, and exhibits crystallinity by orienting the long-chain alkyl groups in the side chains to each other. The monomer unit (a) can form a side chain of a linear alkyl group capable of expressing crystallinity by having the number of carbon atoms C(a) of the alkyl group of 16 or more. In addition, the number of carbon atoms C(a) of the alkyl group of 31 or less can prevent the melting point of the resin from becoming too high. Therefore, by having the number of carbon atoms C(a) within the above range, the crystalline resin A can easily exhibit crystallinity and can express excellent low-temperature fixability.

[0026] The lower limit of the carbon number C(a) of the monomer unit (a) is more preferably 18 or more, and even more preferably 20 or more. The upper limit is more preferably 28 or less, and even more preferably 24 or less. For example, the range of 18 to 28 or 20 to 24 is preferably exemplified.

[0027] The content of crystalline resin A in the toner is 20.0 to 90.0% by mass. By including crystalline resin A in the toner at 20.0% by mass or more, the crystallinity is sufficiently exhibited, and good low-temperature fixability can be achieved. On the other hand, by including crystalline resin A at 90.0% by mass or less, the melt viscosity during fixation can be kept within an appropriate range. Therefore, by including crystalline resin A in the above range, it is possible to suppress the occurrence of hot offset, the deterioration of gloss uniformity of the fixed image, and the deterioration of heat-resistant storage stability, while achieving low-temperature fixability.

[0028] The lower limit of the content of the crystalline resin A based on the mass of the toner is more preferably 30.0 mass% or more, even more preferably 35.0 mass% or more, and still more preferably 40.0 mass% or more. The upper limit is more preferably 85.0 mass % or less, further preferably 75.0 mass % or less, and particularly preferably 65.0 mass % or less. For example, the upper limit is preferably 30.0 to 85.0 mass %, 35.0 to 75.0 mass %, or 40.0 to 65.0 mass %.

[0029] Since the binder resin exhibiting the sharp melt property has a low melt viscosity at or above its melting point, hot offset is likely to occur, and therefore the above-mentioned structure alone is insufficient to prevent hot offset. In the conventional technology, the addition of a crosslinking agent was a common measure against hot offset. This increases the gel content, which is a highly crosslinked portion, and makes it possible to increase the high-temperature elasticity of the toner. However, when the gel component is highly cross-linked, it tends to separate from other resin components, and even if a large amount is added, the effect tends to saturate. Also, the presence of separated low-elasticity components causes hot offset and a decrease in gloss uniformity. Furthermore, it was a method with many disadvantages, such as the inhibition of low-temperature fixability.

[0030] The toner particles contain a straight-chain fatty acid metal salt, and the number of carbon atoms C(a) of the alkyl group contained in the monomer unit (a) and the number of carbon atoms C(b) of the straight-chain fatty acid in the straight-chain fatty acid metal salt satisfy |C(a)-C(b)|≦10, and the valence of the metal in the straight-chain fatty acid metal salt is 2 or more. By satisfying the above, low-temperature fixing ability and hot offset resistance can be achieved at the same time. In the present disclosure, the valence of the metal in the straight-chain fatty acid metal salt is divalent or greater refers to a metal species in which the simple metal ion can have a valence of divalent or greater.

[0031] Satisfying |C(a)-C(b)|≦10 indicates that the number of carbon atoms in the alkyl group of the monomer unit (a) is close to the number of carbon atoms in the straight-chain fatty acid of the straight-chain fatty acid metal salt. Generally, alkyl chains with similar carbon numbers have a high affinity with each other. By incorporating a straight-chain fatty acid metal salt having a carbon number close to that of the alkyl group of the crystalline monomer unit (a) into the toner particles, the affinity between the monomer unit (a) and the straight-chain fatty acid metal salt is increased, making them more compatible with each other.

[0032] Furthermore, since the carbon numbers are similar, it is possible to maintain the crystallinity without disrupting the orientation of the side chains of crystalline resin A, and it is believed that a eutectic-like state can be created between crystalline resin A and the straight-chain fatty acid metal salt. By maintaining the crystallinity of crystalline resin A as described above, it is possible to introduce the straight-chain fatty acid metal salt into crystalline resin A while maintaining the heat-resistant storage stability and low-temperature fixing properties of the toner.

[0033] The upper limit of |C(a)-C(b)| is preferably 8 or less, more preferably 5 or less. The lower limit is not particularly limited, but is preferably 1 or more, more preferably 3 or more. For example, the range may be 1 to 8 or 3 to 5. By satisfying the above, a more preferable effect can be obtained in terms of achieving both low-temperature fixability and heat-resistant storage stability.

[0034] The carbon number C(b) of the straight-chain fatty acid of the straight-chain fatty acid metal salt is not particularly limited, but is preferably 6 or more, more preferably 12 or more, and even more preferably 16 or more. Also, it is preferably 30 or less, more preferably 26 or less, and even more preferably 22 or less. For example, preferred ranges include 6 to 30, 12 to 26, and 16 to 22.

[0035] In the present disclosure, the valence of the metal in the linear fatty acid metal salt contained in the toner particles is 2 or more. It has been found that by satisfying the above, the hot offset resistance of the toner can be improved. As described above, the hot offset resistance can be improved in the process of separating the toner from the fixing member. For this purpose, the melt viscosity of the molten toner is required to be high.

[0036] Fatty acid metal salts containing divalent or higher metals often have two or more alkyl chains, and are easily compatible with the alkyl chains of other binder resin molecules. As a result, when the toner melts in the fixing process and the molecular chains become mobile, the fatty acid metal salts introduced into the molecular chains of the crystalline resin are also introduced into the molecular chains of other crystalline resins, creating a pseudo-crosslinked state and increasing the melt viscosity.

[0037] In addition, it is believed that the greater the charge of the metal in the straight-chain fatty acid metal salt, the more easily it interacts with the polar group of the binder resin, and that the hot offset resistance of the toner is improved by using a polyvalent metal having a valence of 2 or more. The valence of the metal in the straight-chain fatty acid metal salt is preferably 3.

[0038] The straight-chain fatty acid metal salt may have one or more straight-chain fatty acids, but preferably has more than one. It is considered that the presence of more than one straight-chain fatty acid generates an interaction between the metal of the fatty acid metal salt bonded to one binder resin molecule and the hydroxy group of the fatty acid metal salt bonded to the other binder resin molecule, which is preferable in terms of exerting the above-mentioned effect.

[0039] The content of the metal element in the toner particles is 5.0 to 200.0 ppm by mass. When the content of the metal element in the toner particles is 5.0 ppm by mass or more, the melt viscosity increases, and the hot offset resistance can be improved. In addition, by controlling the content to 200.0 ppm by mass or less, the melt viscosity can be prevented from increasing too much, and the decrease in low-temperature fixability can be kept to a minimum.

[0040] The lower limit of the metal content in the toner particles is preferably 10.0 mass ppm or more, more preferably 30.0 mass ppm or more, and even more preferably 50.0 mass ppm or more. The upper limit is preferably 190.0 mass ppm or less, more preferably 170.0 mass ppm or less, and even more preferably 150.0 mass ppm or less. For example, preferred are 10.0 to 190.0 mass ppm, 30.0 to 170.0 mass ppm, and 50.0 to 150.0 mass ppm.

[0041] The toner has a storage modulus G' of 1.0 x 10 7 When the temperature at which the pressure becomes Pa is T1 [°C], the following formula (2) is satisfied. 50.0≦T1≦70.0 (2)

[0042] T1 indicates the temperature at which the elastic modulus of the toner is equivalent to that during sharp melting. By setting T1 at 50.0°C or higher, the toner does not denature even in a high-temperature environment, and the deterioration of the heat-resistant storage stability of the toner can be suppressed. In addition, by setting T1 at 70.0°C or lower, the toner can be melted without applying excessive heat, and therefore excellent low-temperature fixing properties can be achieved.

[0043] T1 can be controlled by the number of carbon atoms in the side chain alkyl group of the crystalline resin contained in the toner, the proportion of long chain alkyl groups in the crystalline resin, the content of crystalline resin A in the toner, and the content of monomer unit (a) in crystalline resin A, etc.

[0044] The lower limit of T1 is preferably 53.0° C. or more, and more preferably 55.0° C. or more. The upper limit is preferably 63.0° C. or less, and more preferably 61.0° C. or less. For example, the preferred range is 53.0 to 63.0° C., or 55.0 to 61.0° C.

[0045] The toner has a storage modulus G' of 1.0 x 10 7 P When the temperature at which a occurs is T1 [°C], the ratio (tan δ) of the loss elastic modulus G" of the toner to the storage elastic modulus G' of the toner at temperature T1 [°C] is tan δ(T1), and tan δ at temperature T1-10 [°C] is tan δ(T1-10), T1, tan δ(T1), and tan δ(T1) / tan δ(T1-10) satisfy the following formulas (3) and (4). 0.3≦tan δ(T1)≦1.0 (3) 1.0≦tanδ(T1) / tanδ(T1-10)≦1.9 (4) By satisfying formula (3), the gloss uniformity of the fixed image becomes good, and by satisfying formula (4), both the gloss uniformity and hot offset resistance of the fixed image can be achieved.

[0046] Generally, the ratio of the loss modulus G" to the storage modulus G' (tan δ) indicates the ease of deformation of a polymer material, i.e., whether it exhibits predominantly elastic or viscous properties. The smaller the tan δ, the more difficult it is to deform, the stronger the elastic properties are, and the more "rubber-like" it becomes. On the other hand, the larger the tan δ, the more easily it is to deform, the stronger the viscous properties are, and the more "gum-like" it becomes.

[0047] Satisfying formula (3) indicates that the toner has appropriate viscoelasticity during low-temperature fixing. Since T1 is the temperature during sharp melting, by keeping tan δ(T1) within the range of formula (3), the toner's ease of deformation during low-temperature fixing is kept appropriate, and gloss uniformity is improved.

[0048] If tan δ(T1) is less than 0.3, the toner has strong elastic properties and is less likely to deform when fixed at low temperatures, resulting in poor gloss on rough paper. On the other hand, if tan δ(T1) is greater than 1.0, the toner has strong viscous properties and is more likely to deform when fixed at low temperatures, resulting in poor gloss uniformity as the toner easily soaks into the paper.

[0049] The lower limit of tan δ(T1) is preferably 0.4 or more, and more preferably 0.5 or more. The upper limit is preferably 0.9 or less, and more preferably 0.8 or less. For example, the range is preferably 0.4 to 0.9, or 0.5 to 0.8.

[0050] Tan δ(T1) can be controlled by the amount of crystalline resin added in the toner. In particular, when the crystalline resin is a vinyl resin having a long-chain alkyl group, it can be controlled by changing the length of the long-chain alkyl group or the ratio of the long-chain alkyl group in the binder resin. It can also be controlled by the type and amount of crosslinking agent added during toner production. Specifically, tan δ(T1) can be increased by increasing the amount of crystalline resin added, increasing the ratio of the long-chain alkyl group in the binder resin, reducing the amount of crosslinking agent, etc. Also, tan δ(T1) can be reduced by reducing the amount of crystalline resin added, decreasing the ratio of the long-chain alkyl group in the binder resin, increasing the amount of crosslinking agent, etc.

[0051] The value of tan δ(T1) / tan δ(T1-10) indicates the change in tan δ in the temperature region around T1 during the occurrence of sharp melting. In toners with little change in tan δ in the temperature range around T1, an appropriate amount of fatty acid metal salt seeps out during fixing, and the release effect of this seeps out, further suppressing hot offset. In addition, by satisfying formula (4), the toner leveling in the fixed image becomes appropriate, making it possible to ensure gloss and gloss uniformity.

[0052] If tan δ(T1) / tan δ(T1-10) is smaller than 1.0, the toner is less likely to deform even if it is sharply melted, and the gloss decreases. If anδ(T1-10) is greater than 1.9, the toner changes rapidly from elastic to viscous properties near the melting start temperature. Therefore, during low-temperature fixing, the toner becomes more easily deformed on the convex parts of the paper and less easily deformed on the concave parts of the paper. As a result, gloss uniformity decreases.

[0053] The lower limit of tan δ(T1) / tan δ(T1-10) is preferably 1.2 or more, and more preferably 1.4 or more. The upper limit is more preferably 1.8 or less, and even more preferably 1.7 or less. For example, the range is preferably 1.2 to 1.8 or 1.4 to 1.7.

[0054] Tan δ(T1) / tan δ(T1-10) can be controlled by the amount of crystalline resin added in the toner. In particular, when the crystalline resin is a vinyl resin having a long-chain alkyl group, it can be controlled by the length of the long-chain alkyl group and the ratio of the long-chain alkyl group in the binder resin. It can also be controlled by the type and amount of crosslinking agent added during toner production. Specifically, tan δ(T1) / tan δ(T1-10) can be increased by increasing the amount of crystalline resin added, increasing the ratio of the long-chain alkyl group in the binder resin, reducing the amount of crosslinking agent, etc. Also, tan δ(T1) / tan δ(T1-10) can be reduced by reducing the amount of crystalline resin added, decreasing the ratio of the long-chain alkyl group in the binder resin, and increasing crosslinking such as by increasing the amount of crosslinking agent.

[0055] The toner's storage elastic modulus G' was 3.0×10 7 The temperature at which the toner storage elastic modulus G' is 3.0×10 6 When the temperature at which the thermal expansion coefficient Pa is T3 [° C.], it is preferable that T2 and T3 satisfy the following formula (5). |T3-T2|≦10.0 (5)

[0056] T2 indicates the temperature at which the elastic modulus corresponds to the time before the toner begins to melt, and T3 indicates the temperature at which the elastic modulus corresponds to the time after the toner has melted.

[0057] T2 is preferably from 45 to 65°C, and more preferably from 50 to 60°C. T3 is preferably from 50 to 70°C, and more preferably from 55 to 65°C.

[0058] |T3-T2| represents the temperature range from the start of toner melting to the end of melting. Satisfying formula (5) means that the toner melts rapidly in a narrow temperature range, that is, it has excellent sharp melting properties. As a result, the toner can achieve both low-temperature fixing properties and heat-resistant storage stability.

[0059] |T3-T2| is preferably 9.0 or less, more preferably 8.0 or less, and even more preferably 7.0 or less. There is no particular lower limit, but it is preferably 3.0 or more, and more preferably 5.0 or more. For example, preferred ranges include 3.0 to 9.0, 3.0 to 8.0, 3.0 to 7.0, and 5.0 to 7.0. |T3-T2| can be controlled by changing the ratio of the crystalline resin contained in the toner, the ratio of the portion exhibiting crystallinity in the crystalline resin, and the like.

[0060] The crystalline resin A will be specifically described below. Examples of the crystalline resin A include vinyl resins, polyester resins, polyurethane resins, and epoxy resins having crystallinity, with vinyl resins having crystallinity being preferred. The crystalline resin A contains 30.0% by mass or more of the monomer unit (a) represented by the formula (1). The formula (1) indicates that the monomer unit (a) has a long-chain alkyl group. In addition, the presence of a long-chain alkyl group makes the resin more likely to exhibit crystallinity. TIFF2024001651000005.tif43170 (in formula (1), R 1 represents a hydrogen atom or a methyl group, L 1 represents a single bond, an ester bond or an amide bond, and m represents an integer of 15 to 30. L 1 is preferably an ester bond, and more preferably the carbonyl in the ester bond -COO- is R 1 is bonded to the carbon having

[0061] In formula (1), m represents an integer of 15 to 30. When m is 15 to 30, the crystalline resin A is more likely to exhibit crystallinity, and a toner having excellent low-temperature fixing ability can be obtained. m is preferably 17-29, and more preferably 19-23.

[0062] As a method for introducing the monomer unit (a), there is a method of polymerizing the following (meth)acrylic acid esters. For example, (meth)acrylic acid esters having a linear alkyl group having 16 to 36 carbon atoms [stearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosanyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, ceryl (meth)acrylate, octacosyl (meth)acrylate, myricyl (meth)acrylate, dotriacontyl (meth)acrylate, etc.] and (meth)acrylic acid esters having a branched alkyl group having 18 to 36 carbon atoms [2-decyltetradecyl (meth)acrylate, etc.] can be mentioned.

[0063] When the crystalline resin A is a vinyl resin having crystallinity, it is possible to have other monomer units in addition to the monomer unit (a). As a method for introducing other monomer units, there is a method of polymerizing the (meth)acrylic acid ester and other vinyl monomers. The other monomer units may be used alone or in combination of two or more kinds.

[0064] Other vinyl monomers include the following: (meth)acrylic acid esters such as styrene, α-methylstyrene, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Monomer having a urea group: for example, a monomer obtained by reacting an amine having 3 to 22 carbon atoms [primary amine (such as normal butylamine, t-butylamine, propylamine, and isopropylamine), secondary amine (such as di-normal ethylamine, di-normal propylamine, and di-normal butylamine), aniline, and cycloxylamine] with an isocyanate having 2 to 30 carbon atoms and an ethylenically unsaturated bond by a known method. Monomers having a carboxy group; for example, methacrylic acid, acrylic acid, 2-carboxyethyl (meth)acrylate, etc. Monomers having a hydroxy group; for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc. Monomers having an amide group; for example, acrylamide, monomers obtained by reacting an amine having 1 to 30 carbon atoms with a carboxylic acid having 2 to 30 carbon atoms (such as acrylic acid and methacrylic acid) having an ethylenically unsaturated bond by a known method, and the like. Of these, it is preferable to use styrene, methacrylic acid, acrylic acid, methyl (meth)acrylate, and t-butyl (meth)acrylate.

[0065] The crystalline resin A preferably has a monomer unit of styrene represented by the following formula (A): The crystalline resin A preferably has a monomer unit of (meth)acrylic acid represented by the following formula (B): TIFF2024001651000006.tif61170 in formula (B), R 3 R represents a hydrogen atom or a methyl group. 3 is preferably a methyl group.

[0066] The content of styrene monomer units in the crystalline resin A is preferably from 1.0 to 75.0 mass %, more preferably from 5.0 to 50.0 mass %, and further preferably from 10.0 to 25.0 mass %. The content of monomer units of (meth)acrylic acid (preferably methacrylic acid) in the crystalline resin A is preferably 1.0 to 5.0 mass %, more preferably 1.0 to 3.0 mass %, and further preferably 1.5 to 2.5 mass %.

[0067] When the crystalline resin A is a polyester resin, a resin exhibiting crystallinity can be used among polyester resins obtainable by reaction of a divalent or higher polyvalent carboxylic acid with a polyhydric alcohol.

[0068] Examples of polycarboxylic acids include the following compounds: Examples of the dibasic acids include succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, malonic acid, and dodecenylsuccinic acid, and their anhydrides or lower alkyl esters, as well as aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid. Other examples include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, and anhydrides or lower alkyl esters thereof. These may be used alone or in combination of two or more.

[0069] Examples of the polyhydric alcohol include the following compounds: Examples of the alkylene glycol include alkylene glycols (ethylene glycol, 1,2-propylene glycol, and 1,3-propylene glycol); alkylene ether glycols (polyethylene glycol and polypropylene glycol); alicyclic diols (1,4-cyclohexanedimethanol); bisphenols (bisphenol A); and alkylene oxide (ethylene oxide and propylene oxide) adducts of alicyclic diols. The alkyl moieties of the alkylene glycols and alkylene ether glycols may be linear or branched. Further examples include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used alone or in combination of two or more. This is also fine.

[0070] For the purpose of adjusting the acid value or hydroxyl value, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can also be used as necessary. The method for producing the polyester resin is not particularly limited, and for example, a transesterification method or a direct polycondensation method can be used alone or in combination.

[0071] The toner particles contain a salt of a straight-chain fatty acid having 6 to 30 carbon atoms and a divalent or higher metal. The divalent or higher metal is not particularly limited, but examples thereof include calcium and aluminum. For example, at least one compound selected from the group consisting of zinc octylate, magnesium distearate, aluminum distearate, calcium distearate, zinc distearate, calcium montanate, calcium laurate, barium laurate, calcium ricinoleate, barium ricinoleate, zinc ricinoleate, etc. may be used.

[0072] The binder resin may contain an amorphous resin in addition to the crystalline resin A. Examples of the amorphous resin include vinyl resin, polyester resin, polyurethane resin, and epoxy resin, and vinyl resin such as polystyrene is preferable. For example, styrene derivatives such as 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, and (meth)acrylic acid esters can be mentioned.

[0073] The content of the crystalline resin A in the binder resin is preferably 20.0 to 90.0% by mass. The content is preferably 30.0 to 85.0 mass %, and more preferably 40.0 to 65.0 mass %. The content of the amorphous resin in the binder resin is preferably 10.0 to 80.0% by mass, more preferably 20.0 to 70.0% by mass, and further preferably 30.0 to 60.0% by mass.

[0074] The binder resin may contain a crosslinking agent as necessary. Examples of the crosslinking agent that can be used include, but are not limited to, the following compounds: Ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, divinylbenzene, bis(4-acryloxypolyethoxyphenyl)propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol #200, #400, #600 diacrylates, dipropylene glycol diacrylate, polypropylene glycol diacrylate and polyester diacrylate (MANDA Nippon Kayaku), as well as the above acrylates replaced with methacrylates. The content of the crosslinking agent in the binder resin is preferably from 0.01 to 10.00% by mass, and more preferably from 0.03 to 5.00% by mass.

[0075] The toner may contain a releasing agent. Examples of the releasing agent include a hydrocarbon wax and an ester wax. By using a hydrocarbon wax and / or an ester wax, it becomes easier to ensure effective releasing properties.

[0076] The hydrocarbon wax is not particularly limited, but examples thereof include the following: Aliphatic hydrocarbon waxes: low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight olefin copolymer, Fischer-Tropsch wax, or waxes obtained by oxidizing or adding an acid to these.

[0077] The ester wax may be any wax having at least one ester bond in one molecule, and may be either a natural ester wax or a synthetic ester wax. The ester wax is not particularly limited, but examples thereof include the following. Esters of monohydric alcohols and monocarboxylic acids, such as behenyl behenate, stearyl stearate, and palmityl palmitate; esters of dihydric carboxylic acids and monoalcohols, such as dibehenyl sebacate; esters of dihydric alcohols and monocarboxylic acids, such as ethylene glycol distearate and hexanediol dibehenate; esters of trihydric alcohols and monocarboxylic acids, such as glycerin tribehenate; esters of tetrahydric alcohols and monocarboxylic acids, such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate; esters of hexahydric alcohols and monocarboxylic acids, such as dipentaerythritol hexastearate, dipentaerythritol hexapalmitate, and dipentaerythritol hexabehenate; esters of polyfunctional alcohols and monocarboxylic acids, such as polyglycerin behenate; natural ester waxes, such as carnauba wax and rice wax.

[0078] Among these, esters of hexahydric alcohols and monocarboxylic acids such as dipentaerythritol hexastearate, dipentaerythritol hexapalmitate, and dipentaerythritol hexabehenate are preferred.

[0079] The release agent may be a hydrocarbon wax or an ester wax, etc., used alone, a combination of a hydrocarbon wax and an ester wax, etc., or a mixture of two or more of each. In particular, a hydrocarbon wax is preferred, and it is preferred to use a hydrocarbon wax alone or a mixture of two or more of the hydrocarbon waxes.

[0080] In the toner, the content of the release agent in the toner particles is preferably 1.0 to 30.0% by mass, more preferably 2.0 to 25.0% by mass. When the content of the release agent in the toner particles is within the above range, releasability during fixing is easily ensured. The melting point of the release agent is preferably 60 to 120° C. When the melting point of the release agent is in the above range, the release agent melts during fixing and easily seeps out onto the toner particle surface, and the release property is easily exhibited. The melting point of the release agent is more preferably 70 to 100° C.

[0081] The toner may contain a colorant. Examples of the colorant include known organic pigments, organic dyes, inorganic pigments, carbon black as a black colorant, magnetic particles, etc. In addition, colorants that have been used in conventional toners may also be used. Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, and 180 are preferably used.

[0082] Magenta colorants include the following: condensed azo compounds, diketopyrrolo Pyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254 are preferably used. Examples of cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds. Specifically, CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66 are preferably used.

[0083] The colorant is selected in consideration of hue angle, chroma, brightness, light resistance, transparency on an OHP sheet, and dispersibility in the toner. The content of the colorant is preferably 1.0 to 20.0 parts by mass with respect to 100.0 parts by mass of the binder resin. When magnetic particles are used as the colorant, the content is preferably 40.0 to 150.0 parts by mass with respect to 100.0 parts by mass of the binder resin.

[0084] If necessary, a charge control agent may be contained in the toner particles. Alternatively, the charge control agent may be added externally to the toner particles. By blending the charge control agent, it becomes possible to stabilize the charge characteristics and control the amount of triboelectric charge optimally according to the development system. Any known charge control agent can be used as the charge control agent, and a charge control agent that can charge quickly and stably maintain a constant charge amount is particularly preferred.

[0085] As the charge control agent that controls the toner to have a negative charge, the following can be mentioned. Organometallic compounds and chelate compounds are effective, and examples thereof include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids and dicarboxylic acid-based metal compounds. The following can be mentioned as the substances that control the toner to have a positive charge. Examples of the organic solvent include nigrosine, quaternary ammonium salts, metal salts of higher fatty acids, diorgano tin borates, guanidine compounds, and imidazole compounds. The content of the charge control agent is preferably 0.01 to 20.0 parts by mass, and more preferably 0.5 to 10.0 parts by mass, relative to 100.0 parts by mass of the toner particles.

[0086] The toner particles may be used as they are as a toner, or may be mixed with an external additive, if necessary, and attached to the surface of the toner particles to form a toner. The external additive may be an inorganic fine particle selected from the group consisting of silica fine particles, alumina fine particles, and titania fine particles, or a composite oxide thereof, etc. Examples of the composite oxide include silica aluminum fine particles and strontium titanate fine particles. The content of the external additive is preferably 0.01 to 8.0 parts by mass, and more preferably 0.1 to 4.0 parts by mass, relative to 100 parts by mass of the toner particles.

[0087] The toner particles may be produced by any conventional method, such as suspension polymerization, emulsion aggregation, dissolution suspension, or pulverization, as long as the method falls within the scope of the present invention. It is preferable to produce the toner particles by suspension polymerization.

[0088] The suspension polymerization method will now be described in detail. For example, a polymerizable monomer composition is prepared by mixing a previously synthesized crystalline resin A, each polymerizable monomer for forming an amorphous resin, and, as necessary, other materials such as a colorant, a release agent, and a charge control agent, and dissolving or dispersing them uniformly. Thereafter, the polymerizable monomer composition is dispersed in an aqueous medium using a stirrer or the like, Suspension particles of the composition are prepared, and then the polymerizable monomer contained in the particles is polymerized with an initiator or the like to obtain toner particles. After the polymerization is completed, the toner particles are filtered, washed and dried by known methods, and external additives are added as necessary to obtain the toner.

[0089] As the polymerization initiator, a known polymerization initiator can be used. Examples of the polymerization initiator include azo or diazo polymerization initiators such as 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile; and peroxide polymerization initiators such as benzoyl peroxide, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide. Furthermore, the molecular weight may be adjusted using a known chain transfer agent or polymerization inhibitor.

[0090] The aqueous medium may contain an inorganic or organic dispersion stabilizer. As the dispersion stabilizer, known dispersion stabilizers can be used. Examples of inorganic dispersion stabilizers include phosphates such as hydroxyapatite, tricalcium phosphate, dicalcium phosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; metal hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide; sulfates such as calcium sulfate and barium sulfate; calcium metasilicate; bentonite; silica; and alumina.

[0091] On the other hand, examples of organic dispersion stabilizers include polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salts, and starch.

[0092] When an inorganic compound is used as the dispersion stabilizer, a commercially available product may be used as it is, but in order to obtain finer particles, the inorganic compound may be formed in an aqueous medium and then used. For example, in the case of calcium phosphates such as hydroxyapatite or tricalcium phosphate, an aqueous solution of the phosphate may be mixed with an aqueous solution of the calcium salt under high agitation.

[0093] The aqueous medium may contain a surfactant. As the surfactant, a known surfactant can be used. For example, anionic surfactants such as sodium dodecylbenzene sulfate and sodium oleate, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. can be mentioned.

[0094] The calculation and measurement methods for various physical properties are described below. <Method for measuring storage modulus G' and tan δ> The storage modulus G' and tan δ are measured using a viscoelasticity measuring device (rheometer) ARES (manufactured by Rheometrics Scientific). The outline of the measurement is described in the ARES Operation Manuals 902-30004 (August 1997 edition) and 902-00153 (July 1993 edition) published by Rheometrics Scientific, and is as follows. Measurement tool: torsion rectangular Measurement sample: Toner was measured using a pressure molding machine, measuring 12 mm in width, 20 mm in height, and 2.5 mm in thickness. A rectangular parallelepiped sample of 2 mm is prepared (maintain 25 kN for 30 minutes at room temperature). The pressure molding machine used is the 100 kN press NT-100H manufactured by NPa Systems. Leave the jig and sample at room temperature (23°C) for 1 hour, then attach the sample to the jig. See Figure 1. As shown in the figure, fix the sample so that the width of the measurement area is 12.0 mm, the thickness is 2.5 mm, and the height is 10.0 mm. After regulating the temperature to 30°C for 10 minutes, the measurement is performed with the following settings. Measurement frequency: 6.28 rad / s Measurement distortion setting: Set the initial value to 0.1% and perform the measurement in automatic measurement mode. - Sample elongation correction: Adjusted in automatic measurement mode Measurement temperature: 30℃ to 150℃ at a rate of 2℃ per minute Measurement interval: Measure viscoelastic data every 30 seconds, i.e., every 1°C. Data is transferred via an interface to RSI Orchestrator (control, data acquisition and analysis software) (manufactured by Rheometrics Scientific) running on Microsoft Windows 2000. Among the measured data, the storage modulus G' is 1.0×10 7 The temperature at which the storage modulus G' becomes 3.0×10 is T1 [℃]. 7 The temperature at which the storage modulus G' is 3.0×10 6 The temperature at which the elastic modulus G" is Pa is defined as T3 [°C]. The ratio (tan δ) of the loss modulus G" to the storage modulus G' at temperature T1 [°C] is defined as tan δ(T1), and tan δ at temperature T1-10 [°C] is defined as tan δ(T1-10).

[0095] <Method of separating toner particles from a toner> When analyzing toner particles, if the surfaces of the toner particles have been treated with an external additive or the like, the external additive is separated by the following method to obtain toner particles. Add 160 g of sucrose (Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a concentrated sucrose solution. Place 31 g of the concentrated sucrose solution and 6 mL 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.) in a centrifuge tube to prepare a dispersion. Add 1.0 g of toner to this dispersion and break up any toner clumps with a spatula or similar. Shake the centrifuge tube with a shaker at 350 strokes per minute (spm) for 20 minutes. After shaking, transfer the solution to a glass tube (50 mL) for a swing rotor and separate in a centrifuge at 3,500 rpm for 30 minutes. This operation separates the toner particles from the detached external additives. Visually check that the toner and the aqueous solution are sufficiently separated, and collect the toner that has separated to the top layer with a spatula. The collected toner is filtered through a vacuum filter, and then dried in a dryer for at least one hour to obtain toner particles. This operation is repeated several times to ensure the required amount.

[0096] <Method for separating crystalline resin A from toner particles> The crystalline resin A can be separated from the toner by a known method, and an example thereof will be described below. Gradient polymer LC is used as a method for separating resin components from toner. This analysis allows separation according to the polarity of the resin in the binder resin, regardless of the molecular weight.

[0097] First, the toner is dissolved in chloroform. The sample concentration is adjusted to 0.1% by mass in chloroform, and the solution is filtered through a 0.45 μm PTFE filter before being used for measurement. The measurement conditions for gradient polymer LC are shown below. Equipment: UlTIMATE3000 (Thermo Fisher Scientific) Mobile phase: A Chloroform (HPLC), B Acetonitrile (HPLC) Gradient: 2min (A / B=0 / 100) → 25min (A / B=100 / 0) (Note that the gradient of the change in the mobile phase was made linear.) Flow rate: 1.0mL / min Injection: 0.1% by mass x 20μL Column: Tosoh TSKgel ODS (4.6mmφx150mm x 5μm) Column temperature: 40℃ Detector: Corona Charged Aerosol Detector (Corona-CAD) (Thermo Fisher Scientific)

[0098] The time-intensity graph obtained from the measurement shows that the resin components can be separated into two peaks depending on the polarity. After that, the above measurement is carried out again, and by taking fractions at the time when each peak reaches its valley, it is possible to separate the two types of resin. The separated resins are subjected to DSC measurement, and the resins having a melting point peak are designated as crystalline resin A.

[0099] If the toner contains a release agent, it is necessary to separate the release agent from the toner. The release agent is separated by recycling HPLC to separate components with a molecular weight of 2000 or less as the release agent. The measurement method is as follows. First, a chloroform solution of the toner is prepared by the method described above. The resulting solution is then filtered through a solvent-resistant membrane filter "Myshoridisc" (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of components soluble in chloroform is 1.0 mass %. This sample solution is used to perform measurements under the following conditions. ·Equipment: LC-Sakura NEXT (manufactured by Nippon Analytical Industry Co., Ltd.) Column: JAIGEL 2H, 4H (Japan Analytical Industry Co., Ltd.) Eluent: Chloroform ·Flow rate: 10.0ml / min Oven temperature: 40.0℃ Sample injection volume: 1.0ml In calculating the molecular weight of the sample, a molecular weight calibration curve prepared using standard polystyrene resins (e.g., trade names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500" manufactured by Tosoh Corporation) is used. From the molecular weight curve thus obtained, components having a molecular weight of 2000 or less are repeatedly separated and the release agent is removed from the toner.

[0100] <Method of measuring the content of monomer unit (a) in resin and the number of carbon atoms in the alkyl group> The content of the monomer unit (a) in the resin and the number of carbon atoms in the alkyl group are measured by 1 The measurement is performed by H-NMR under the following conditions. The crystalline resin A separated by the above-mentioned method can be used as the measurement sample. Measuring device: FT NMR device JNM-EX400 (manufactured by JEOL Ltd.) Measurement frequency: 400MHz Pulse condition: 5.0μs Frequency range: 10500Hz Number of times: 64 Measurement temperature: 30℃ Sample: 50 mg of the measurement sample is placed in a sample tube with an inner diameter of 5 mm, deuterated chloroform (CDCl3) is added as a solvent, and this is dissolved in a constant temperature bath at 40°C to prepare the sample. Obtained 1 The H-NMR chart is analyzed to identify the structure of each monomer unit. As an example, the measurement of the content of the monomer unit (a) in the crystalline resin A and the number of carbon atoms in the alkyl group will be described. Obtained 1 In the H-NMR chart, a peak that is independent of the peaks that are attributable to the components of the monomer unit (a) is selected from the peaks that are attributable to the components of the other monomer units, and the integral value S1 of this peak is calculated. The integral values ​​of the other monomer units contained in the crystalline resin A are also calculated in the same manner.

[0101] When the monomer units constituting the crystalline resin A are the monomer unit (a) and one other monomer unit, the content of the monomer unit (a) is determined as follows using the above integral value S1 and the integral value S2 of the peak of the other monomer unit, where n1 and n2 are the numbers of hydrogen atoms in the constituent elements to which the peak of interest for each site belongs. Content of monomer unit (a) (mol%)= {(S1 / n1) / ((S1 / n1)+(S2 / n2))}×100 Even when two or more types of other monomer units are present, the content of the monomer unit (a) can be calculated in a similar manner (using S3···Sx, n3···nx). The number of carbon atoms in the alkyl group is 1 It can be calculated from the integral ratio of the proton peak in the H-NMR chart.

[0102] In addition, when a polymerizable monomer that does not contain a hydrogen atom in any component other than the vinyl group is used, 13 Measure nuclei using C-NMR 13 C, and the measurement was performed in single pulse mode. 1 Calculation is performed in the same manner using H-NMR. In addition, the measurement results of infrared absorption spectrum (IR) and gas chromatography-mass spectrometry (GC-MS) may be used as necessary. The proportion (mol %) of each monomer unit calculated by the above method is multiplied by the molecular weight of each monomer unit to convert the content of each monomer unit into mass %.

[0103] <Measurement of the content of crystalline resin A in the toner> In the method for separating crystalline resin A from toner particles described above, the content of crystalline resin A in the toner is calculated based on the mass of the toner before it is dissolved in chloroform and the mass of crystalline resin A separated from the toner particles.

[0104] <Method for separating fatty acid metal salt from toner particles> 10.0 g of toner particles from which the external additives have been separated are weighed out, placed in a cylindrical filter paper (Toyo Roshi No. 84) and subjected to a Soxhlet extractor. 200 mL of tetrahydrofuran (THF) is added as a solvent and extraction is performed for 20 hours, and the THF-insoluble matter remaining on the cylindrical filter paper is dried to solidify. The obtained THF-insoluble matter is placed again in the cylindrical filter paper and subjected to a Soxhlet extractor. 200 mL of chloroform is added as a solvent and extraction is performed for 8 hours. The extract is concentrated and dried to separate the fatty acid metal salt from the toner particles. The operation is repeated as necessary to obtain the required amount of fatty acid metal salt. <Measurement of the carbon number of straight-chain fatty acids in straight-chain fatty acid metal salts> After the fatty acid metal salt is extracted by the above-mentioned method, the carbon number is measured by the same method as the above-mentioned method for measuring the carbon number of the alkyl group.

[0105] <Identification of the valence of the metal in the metal salt of straight chain fatty acid> After the fatty acid metal salts are extracted by the above-mentioned method, the types of metals contained in the straight-chain fatty acid metal salts are analyzed using an inductively coupled plasma atomic emission spectrometer (ICP-AES (manufactured by Seiko Instruments Inc.)). As a pretreatment, 100.0 mg of fatty acid metal salt was added to 60% nitric acid (Kanto Chemical, atomic absorption spectrometry) During acid digestion, the internal temperature was measured using a microwave high-power sample pretreatment device ETHOS1600 (Milestone General Co., Ltd.). The solution is treated in a sealed container at 220°C for 1 hour to prepare a polyvalent metal element-containing solution sample. Ultrapure water is then added to the solution until the total weight is 50.00 g, which is used as a measurement sample. A calibration curve is prepared for each metal element, and the type of metal contained in the fatty acid metal salt is identified, and the valence of the metal is determined from the type. In the present disclosure, the valence of the metal in the linear fatty acid metal salt is divalent or higher refers to a metal species in which the metal ion can have a valence of divalent or higher.

[0106] <Method for measuring metal content in toner particles> The metal content in the toner particles is measured using fluorescent X-rays and is determined using a calibration curve method. The fluorescent X-ray measurement conforms to JIS K 0119-1969, and is specifically as follows. The measurement equipment used was a wavelength dispersive X-ray fluorescence analyzer "Axios" (PANalytical) and the accompanying software "SuperQ" for setting measurement conditions and analyzing measurement data. ver.4.0F" (PANalytical). Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, and the measurement diameter (collimator mask diameter) is 27 mm. A proportional counter (PC) is used to measure light elements, and a scintillation counter (SC) is used to measure heavy elements.

[0107] [Creating a calibration curve for aluminum element] First, pellets are prepared to create a calibration curve for determining the metal content in the toner particles. Binder [product name: Spectro Blend, components: C 81.0, O 2.9, H 13.5, N 2.6 (mass%), chemical formula: C 19 H 38 Add 1.0 part by mass of aluminum hydroxide (Al(OH)3) to 100 parts by mass of 100% ethanol (ON, shape: powder (44 μm); manufactured by Rigaku Corporation) and thoroughly mix using a coffee mill to obtain a mixture. The pellets for measurement are molded using a tablet press "BRE-32" (Maekawa Test Machinery Manufacturing Co., Ltd.). 4 g of the above mixture is placed in a dedicated aluminum ring for pressing and flattened. Then, using the tablet press, it is pressed at 20 MPa for 60 seconds to prepare pellets with a thickness of 2 mm and a diameter of 39 mm.

[0108] Similarly, aluminum hydroxide is mixed in amounts of 10.0 parts by mass, 50.0 parts by mass, 200.0 parts by mass, and 500.0 parts by mass per 100 parts by mass of binder, and pellets are molded. The pellets obtained are analyzed with a wavelength dispersive X-ray fluorescence analyzer using PET as a spectroscopic crystal, and the count rate (unit: cps) of Al-Kα rays observed at a diffraction angle (2θ) of 144.8° is measured. At this time, the acceleration voltage and current value of the X-ray generator are 32 kV and 125 mA, respectively, and the measurement time is 10 seconds. A linear calibration curve is obtained by plotting the obtained X-ray count rate on the ordinate and the aluminum concentration calculated from the amount of aluminum hydroxide added in each calibration sample on the abscissa.

[0109] [Quantitative analysis of aluminum elements in toner particles] To quantify the aluminum element content in the toner particles, 4 g of toner particles are placed in a dedicated aluminum ring for pressing and pelletized in the same manner as the sample for creating the calibration curve. The pellets of the molded toner particles are measured under the same conditions as the calibration curve sample, and the aluminum element content (ppm by mass) in the toner particles is determined from the calibration curve that has been created.

[0110] [Creating a calibration curve for magnesium element and quantifying magnesium element in toner particles] A calibration sample is prepared using the same process as above, except that magnesium hydroxide (Mg(OH)2) is used instead of aluminum hydroxide (Al(OH)3) as the metal component. The count rate (unit: cps) of the Mg-Kα ray observed at a diffraction angle (2θ) of 22.93° when PET is used as the analyzing crystal is measured with the acceleration voltage and current of the X-ray generator set at 32 kV and 125 mA, and the measurement time set at 50 seconds. Linear correlation with magnesium element addition concentration Obtain a calibration curve. To quantify the magnesium content in the toner particles, a toner particle sample is prepared in the same manner as for quantifying the aluminum element, and measurements are carried out under the same conditions as for the calibration curve sample. The magnesium element content (ppm by mass) in the toner particles is then determined from the calibration curve for the magnesium element.

[0111] [Creation of a calibration curve for calcium element and quantitative determination of calcium element in toner particles] A calibration sample is prepared using the same process as above, except that calcium hydroxide (Ca(OH)2) is used instead of aluminum hydroxide (Al(OH)3) as the metal component. The count rate (unit: cps) of the Ca-Kα ray observed at a diffraction angle (2θ) of 113.0° when PET is used as the analyzing crystal is measured, with the acceleration voltage and current of the X-ray generator set at 32 kV and 125 mA, and the measurement time set at 10 seconds. A calibration curve is obtained in linear correlation with the calcium element addition concentration. To quantify the calcium content in the toner particles, a toner particle sample is prepared in the same manner as for quantifying the aluminum element, and measurements are carried out under the same conditions as for the calibration curve sample. The calcium element content (ppm by mass) in the toner particles is then determined from the calibration curve for the calcium element.

[0112] [Creating a calibration curve for iron and quantifying iron in toner particles] A calibration sample is prepared using the same process as above, except that iron oxide (Fe2O3) is used instead of aluminum hydroxide (Al(OH)3) as the metal component. The count rate (unit: cps) of the Fe-Kα ray observed at a diffraction angle (2θ) of 57.48° when PET is used as the analyzing crystal is measured, with the acceleration voltage and current of the X-ray generator set at 60 kV and 66 mA, and the measurement time set at 10 seconds. A calibration curve is obtained as a linear correlation to the iron element addition concentration. To quantify the iron content in the toner particles, a toner particle sample is prepared in the same manner as for quantifying the aluminum element, and measurements are performed under the same conditions as for the calibration curve sample. The iron element content (ppm by mass) in the toner particles is then determined from the calibration curve for the iron element.

[0113] [Creation of calibration curves for other metal elements and quantification of the metal elements in toner particles] When measuring elements other than those mentioned above using fluorescent X-rays, set the product of the tube voltage (kV) and tube current (mA) of the X-ray generator's tube bulb to 4.0 kW, and measure for 10 seconds. Other than that, perform the quantitative analysis in the same way as for aluminum element. The total content of each metal element in the toner particles determined by the above method is defined as the metal content in the toner particles. EXAMPLES

[0114] The present disclosure will be specifically described below with reference to examples, but these are not intended to limit the present disclosure in any way. In the following formulations, parts are by weight unless otherwise specified.

[0115] (Preparation of Crystalline Resin A1) The following materials were placed in a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube under a nitrogen atmosphere. Toluene 100.0 parts Monomer composition 100.0 parts (The monomer composition is a mixture of the following monomers in the ratio shown below.) (Docosyl acrylate (monomer (a)) 80.0 parts) (18.0 parts styrene) (Methacrylic acid 2.0 parts) Polymerization initiator: 0.5 parts t-butyl peroxypivalate (NOF Corp.: Perbutyl PV) The inside of the reaction vessel was heated to 70° C. while stirring at 200 rpm to carry out a polymerization reaction for 12 hours, thereby obtaining a solution in which the polymer of the monomer composition was dissolved in toluene. After cooling to 25°C, the above solution was poured into 1000.0 parts of methanol while stirring to precipitate the methanol insoluble matter. The resulting methanol insoluble matter was filtered off, washed with methanol, and vacuum dried at 40°C for 24 hours to obtain crystalline resin A1.

[0116] (Preparation of Crystalline Resins A2 to A11) Crystalline Resins A2 to A11 were prepared in the same manner as in the preparation of Crystalline Resin A1, except that the types and amounts of monomer compositions added were changed as shown in Table 1. [Table 1] <Example 1> [Toner production by suspension polymerization method] (Production of toner particles 1) Styrene 50.0 parts Colorant Pigment Blue 15:3 6.5 parts A mixture of the above materials was prepared. The mixture was placed in an attritor (manufactured by Nippon Coke Corporation) and dispersed at 200 rpm for 2 hours using zirconia beads with a diameter of 5 mm to obtain a raw material dispersion.

[0117] On the other hand, 735.0 parts of ion-exchanged water and 16.0 parts of trisodium phosphate (12-hydrate) were added to a container equipped with a high-speed stirring device homomixer (manufactured by Primix Corporation) and a thermometer, and the temperature was raised to 60 ° C. while stirring at 12000 rpm. An aqueous calcium chloride solution in which 9.0 parts of calcium chloride (2-hydrate) was dissolved in 65.0 parts of ion-exchanged water was added thereto, and the mixture was stirred at 12000 rpm for 30 minutes while maintaining the temperature at 60 ° C. 10% hydrochloric acid was added thereto to adjust the pH to 6.0, and an aqueous medium in which an inorganic dispersion stabilizer containing hydroxyapatite was dispersed in water was obtained.

[0118] Next, the raw material dispersion liquid was transferred to a container equipped with a stirrer and a thermometer, and the temperature was raised to 60° C. while stirring at 100 rpm. ·Crystalline resin A1: 50.0 parts Release agent: 9.0 parts (Release agent: DP18 (dipentaerythritol stearate wax, melting point 79°C, manufactured by Nippon Seiro Co., Ltd.) Crosslinking agent (divinylbenzene) 0.05 parts Fatty acid metal salt (aluminum distearate) 0.5 parts The above materials were added thereto and stirred at 100 rpm for 30 minutes while maintaining the temperature at 60°C, and then 9.0 parts of t-butyl peroxypivalate (Perbutyl PV, manufactured by NOF Corp.) was added as a polymerization initiator and stirred for another minute. Thereafter, the mixture was poured into the aqueous medium being stirred at 12,000 rpm in the high-speed stirring device. Stirring was continued at 12,000 rpm for 20 minutes to obtain a granulation liquid. The granulation liquid was transferred to a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube, and heated to 70° C. while stirring at 150 rpm under a nitrogen atmosphere. A polymerization reaction was carried out at 150 rpm for 12 hours while maintaining the temperature at 70° C., to obtain a toner particle dispersion liquid. The resulting toner particle dispersion was cooled to 45°C while stirring at 150 rpm, and then heat-treated for 5 hours while maintaining the temperature at 45°C. Dilute hydrochloric acid was then added while maintaining the stirring until the pH reached 1.5 to dissolve the dispersion stabilizer. The solid content was filtered off, thoroughly washed with ion-exchanged water, and vacuum-dried at 30°C for 24 hours to obtain toner particles 1.

[0119] (Preparation of Toner 1) For the above toner particles, 1:98.0 parts, silica fine particles (hydrophobized with hexamethyldisilazane, number-average particle size of primary particles: 10 nm, BET specific surface area: 170 m) were added as an external additive. 2 The mixture was mixed for 15 minutes at 3000 rpm using a Henschel mixer (manufactured by Nippon Coke Corporation) to obtain toner 1. The physical properties of the obtained toner 1 are shown in Table 3. Furthermore, the results of evaluation by the toner evaluation method described below are shown in Table 4.

[0120] [Table 2]

[0121] In Table 2 above, "metal valence" refers to the valence of the metal element of the straight chain fatty acid metal salt in the toner particles.

[0122] <Examples 2 to 22 and Comparative Examples 1 to 11> Toner particles 2 to 22 and comparative toner particles 1 to 11 were obtained in the same manner as in Example 1, except that the materials and amounts added were changed as shown in Table 2. The physical properties of the toner particles are shown in Table 2. As shown in. Furthermore, external addition was carried out in the same manner as in Example 1 to obtain toners 2 to 22 and comparative toners 1 to 11. The physical properties of the toners are shown in Table 3. Furthermore, the results of evaluation by the toner evaluation method described below are shown in Table 4. From the above analysis, in toners 1 to 22 and comparative toners 1 to 11, each monomer unit forming crystalline resin A was contained in the same content ratio as in the formulation shown in Table 1.

[0123] [Table 3]

[0124] In Table 3, "content of monomer unit (a)" indicates the content ratio in crystalline resin A. Also, "content of crystalline resin A" indicates the content in the toner. "Content of metal" refers to the total content of each metal contained in the toner particles measured by the above-mentioned method.

[0125] <Toner Evaluation Method> <1> Low temperature fixability The process cartridges filled with toners 1 to 22 and comparative toners 1 to 11 were left to stand for 48 hours at 25°C and 40% RH. Using an LBP-712Ci that had been modified so that it could operate even without the fixing unit, an unfixed image was printed out with an image pattern in which 9 10 mm x 10 mm square images were evenly arranged on the entire transfer paper. The amount of toner on the transfer paper was 0.80 mg / cm. 2 The fixing start temperature was evaluated. The transfer paper was A4 size paper ("Prover Bond paper": 105 g / m 2 (Fox River) was used. The fixing unit was an external fixing unit that had been removed from the LBP-712Ci and was designed to operate outside the laser beam printer. The fixing temperature of the external fixing unit was raised in 5°C increments from 90°C, and fixing was performed at a process speed of 260mm / sec. The fixed image was visually observed, and the lowest temperature at which no cold offset occurred was defined as the fixing start temperature, and the low-temperature fixing ability was evaluated according to the following criteria. The evaluation results are shown in Table 4. [Evaluation Criteria] A: Fixing start temperature is 100℃ or less B: Fixing start temperature is 105℃ or higher and 110℃ or lower C: Fixing start temperature is 115℃ or higher and 120℃ or lower D: Fixing start temperature exceeds 120°C

[0126] <2> Heat resistance / blocking resistance 10 g of toner was placed in a 100 mL resin cup and left for 7 days in an environment with a temperature of 45°C and a humidity of 95%, after which the degree of agglomeration was visually confirmed and the heat resistance storage stability was evaluated according to the following criteria. The evaluation results are shown in Table 4. (Evaluation Criteria) A: No aggregates were observed. B: Agglomerates are visible but easily disintegrate. C: Agglomerates are visible, but can be broken down by shaking. D: The aggregates can be grasped and do not easily crumble.

[0127] <3> Evaluation of gloss and gloss unevenness the above <1> The fixed image at the fixing start temperature in the evaluation of 1 was used. The gloss value was measured using a handy gloss meter PG-1 (manufactured by Nippon Denshoku Industries Co., Ltd.). The measurement conditions were set at 75° for the projection angle and reception angle, and all image patterns arranged at 9 points were measured and the average value was evaluated. The standard deviation of the measurement values ​​was used to evaluate gloss unevenness. The evaluation results are shown in Table 4. [Gross evaluation criteria] A: The average gross value is 25.0 or more. B: The average gross value is 20.0 or more and less than 25.0 C: Average gross value is 15.0 or more and less than 20.0 D: Average gross value is less than 15.0 [Gross unevenness evaluation criteria] A: Gross standard deviation is 1.00 or less B: Gross standard deviation is greater than 1.00 and less than or equal to 2.00 C: Gross standard deviation is greater than 2.00 and less than or equal to 3.00 D: Gross standard deviation exceeds 3.00

[0128] <4> Evaluation of hot offset resistance In a normal temperature and humidity environment (25°C / 50%RH), the process speed was 260 mm / sec, and the fixing temperature was increased in 10°C increments while printing a solid image (toner load: 0.9 mg / cm 2 The transfer material was plain paper (LETTER size XEROX 4200 paper, manufactured by XEROX, 75 g / m 2 The occurrence of hot offset was visually confirmed and evaluated according to the following criteria depending on the temperature at which it occurred. The evaluation results are shown in Table 4. [Evaluation criteria for hot offset resistance] A: Offset occurs at 160℃ or higher B: Offset occurs at temperatures between 150℃ and 160℃ C: Offset occurs at temperatures between 140℃ and 150℃ D: Offset occurs below 140℃

[0129] [Table 4]

[0130] As is clear from Table 4, compared with Comparative Examples 1 to 11, Examples 1 to 22 provide toners which combine excellent low-temperature fixing property, heat-resistant storage stability, and hot offset resistance, and further have excellent gloss uniformity on rough paper. The present disclosure relates to the following configurations. (Configuration 1) A toner having toner particles containing a binder resin, The binder resin contains a crystalline resin A, (i) the crystalline resin A contains a monomer unit (a) represented by the following formula (1), TIFF2024001651000011.tif43170 (In formula (1), R1 represents a hydrogen atom or a methyl group, L1 represents a single bond, an ester bond or an amide bond, and m represents an integer of 15 to 30.) (ii) the content of the monomer unit (a) in the crystalline resin A is 30.0% by mass or more, (iii) the monomer unit (a) contains an alkyl group having a carbon number C(a) of 16 to 31; (iv) the content of the crystalline resin A in the toner is 20.0 to 90.0% by mass, In the viscoelasticity measurement of the toner, the temperature at which the storage elastic modulus G' of the toner becomes 1.0×10 Pa is defined as T1 [° C.], The ratio (tan δ) of the loss elastic modulus G″ of the toner to the storage elastic modulus G′ of the toner at a temperature T1 [° C.] is defined as tan δ(T1), When tan δ at temperature T1-10 [℃] is tan δ(T1-10), The T1, the tan δ(T1), and the tan δ(T1-10) satisfy the following formulas (2) to (4), 50.0≦T1≦70.0 (2) 0.3≦tan δ(T1)≦1.0 (3) 1.0≦tanδ(T1) / tanδ(T1-10)≦1.9 (4) The toner particles are Contains a metal salt of a straight chain fatty acid, the number of carbon atoms C(a) of the alkyl group and the number of carbon atoms C(b) of the straight-chain fatty acid of the straight-chain fatty acid metal salt are |C(a)-C(b)|≦10 is satisfied, The toner is characterized in that the valence of the metal in the straight-chain fatty acid metal salt is divalent or greater. (Configuration 2) The toner according to configuration 1, wherein the content of the metal element in the toner particles is 5.0 to 200.0 ppm by mass. (Configuration 3) The toner according to configuration 1 or 2, wherein the number of carbon atoms C(a) of the alkyl group and the number of carbon atoms C(b) of the straight-chain fatty acid of the straight-chain fatty acid metal salt satisfy |C(a)-C(b)|≦5. (Configuration 4) 4. The toner according to any one of configurations 1 to 3, wherein the valence of the metal in the linear fatty acid metal salt is trivalent. (Configuration 5) 5. The toner according to any one of configurations 1 to 4, wherein the content of the monomer unit (a) in the crystalline resin A is 50.0 to 90.0% by mass. (Configuration 6) In the viscoelasticity measurement of the toner, the temperature at which the storage elastic modulus G' of the toner becomes 3.0×10 Pa is defined as T2 [° C.], When the temperature at which the storage modulus G' of the toner becomes 3.0×106 Pa is T3 [° C.], The toner according to any one of configurations 1 to 5, wherein T2 and T3 satisfy the following formula (5): |T3-T2|≦10.0 (5) (Configuration 7) 7. The toner according to claim 1, wherein the straight-chain fatty acid metal salt is at least one selected from the group consisting of aluminum distearate, calcium montanate, and calcium laurate.

Claims

1. A toner having toner particles containing a binder resin, The binder resin contains a crystalline resin A, (i) The crystalline resin A contains a monomer unit (a) represented by the following formula (1), (In formula (1), R １ represents a hydrogen atom or a methyl group; L １ represents a single bond, an ester bond, or an amide bond, and m is an integer of 15 to 30. (ii) the content of the monomer unit (a) in the crystalline resin A is 30.0% by mass or more, (iii) the monomer unit (a) contains an alkyl group having a carbon number C(a) of 16 to 31; (iv) the content of the crystalline resin A in the toner is 20.0 to 90.0% by mass, In the viscoelasticity measurement of the toner, the storage elastic modulus G′ of the toner is 1.0×10 ７ The temperature at which the temperature becomes Pa is T1 [°C], The ratio (tan δ) of the loss elastic modulus G″ of the toner to the storage elastic modulus G′ of the toner at a temperature T1 [° C.] is defined as tan δ(T1), When tan δ at temperature T1-10 [°C] is tan δ(T1-10), The T1, the tan δ(T1), and the tan δ(T1-10) satisfy the following formulas (2) to (4), 50.0≦T1≦70.0 (2) 0.3≦tanδ(T1)≦1.0 (3) 1.0≦tanδ(T1) / tanδ(T1-10)≦1.9 (4) The toner particles are Contains a metal salt of a straight chain fatty acid, the number of carbon atoms C(a) of the alkyl group and the number of carbon atoms C(b) of the straight-chain fatty acid of the straight-chain fatty acid metal salt are |C(a)-C(b)|≦10 is satisfied, The toner is characterized in that the valence of the metal in the straight-chain fatty acid metal salt is divalent or greater.

2. 2. The toner according to claim 1, wherein the content of the metal element in the toner particles is 5.0 to 200.0 ppm by mass.

3. 3. The toner according to claim 1, wherein the number of carbon atoms C(a) of the alkyl group and the number of carbon atoms C(b) of the straight-chain fatty acid of the straight-chain fatty acid metal salt satisfy |C(a)-C(b)|≦5.

4. 3. The toner according to claim 1, wherein the valence of the metal in the straight-chain fatty acid metal salt is trivalent.

5. 3. The toner according to claim 1, wherein the content of the monomer unit (a) in the crystalline resin A is 50.0 to 90.0% by mass.

6. In the viscoelasticity measurement of the toner, the storage elastic modulus G′ of the toner is 3.0×10 ７ The temperature at which the pressure reaches Pa is T2 [°C]. The storage elastic modulus G' of the toner is 3.0×10 ６ When the temperature at which the pressure becomes Pa is T3 [℃], The toner according to claim 1 or 2, wherein T2 and T3 satisfy the following formula (5): |T3-T2|≦10.0 (5)

7. 3. The toner according to claim 1, wherein the metal salt of a straight chain fatty acid is at least one selected from the group consisting of aluminum distearate, calcium montanate, and calcium laurate.

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