toner

Abstract

To provide a toner that can achieve stable cleaning properties and image quality even after a long-term durable use by using paper containing a large amount of paper powder in a low-temperature and low-humidity environment where cleaning stability is not easily achieved.SOLUTION: A toner contains a toner particle containing a binder resin, and fatty acid metal salt particles and hydrotalcite particles on the surface of the toner particle. The hydrotalcite particles contain fluorine. In line analysis in STEM-EDS mapping analysis of the toner, fluorine exists inside the hydrotalcite particles. When the area ratio of the fatty acid metal salt particles to the toner particle is defined as S1(%), and the area ratio of the hydrotalcite particles to the toner particle as H1(%) in the EDS measurement field of view, which are measured by the STEM-EDS mapping analysis of the toner, S1 / H1 is 0.25-9.00.SELECTED DRAWING: None

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates to toners used in imaging processes such as electrophotography. [Background technology]

[0002] In recent years, electrophotographic image forming apparatuses such as multifunction peripherals and printers have been required to have longer life, smaller size, lower cost, and media redundancy. Recently, from the perspective of reducing costs in offices and making effective use of paper resources, users are increasingly using cheaper rough paper and talc paper than before. Such paper is prone to generating paper dust inside the printer. Therefore, if such paper is used continuously over a long period of time in a printer, the paper dust can reduce the cleaning ability of the photoreceptor surface, contaminate the components used in the charging means, and reduce the ability to impart charge to the photoreceptor. This can result in a decline in image quality at the end of the printer's life.

[0003] Such a requirement can be met, for example, by providing a means for cleaning the charging means or by using a non-contact charging means such as a corona charging method, but this can lead to increased costs for the parts and can be an obstacle when trying to make the printer smaller.

[0004] On the other hand, in order to extend the life of printers, it is necessary to stabilize the chargeability of toner even during long-term use of the printer. As a means for increasing the negative chargeability of a toner, Patent Document 1 discloses that the chargeability of a toner can be increased by using a toner containing hydrotalcite particles. Furthermore, Patent Document 2 discloses that by using a toner containing a fatty acid metal salt as a cleaning aid, cleaning properties are improved and retransfer is suppressed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-198929 [Patent Document 2] Patent Publication No. 2021-009251 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the toner disclosed in Patent Document 1, the hydrotalcite particles are highly positive particles, which increases the chargeability of the toner, but on the other hand, it has been found that in low-temperature, low-humidity environments, the hydrotalcite particles themselves become strongly positive and are prone to electrostatic aggregation. Therefore, there is room for improvement in the charge stability of the toner during long-term use of the printer. Furthermore, the toner disclosed in Patent Document 2 leaves room for improvement in terms of the durability of its cleaning properties on the photoreceptor surface when using paper that generates a lot of paper dust and when the printer is used for long-term durability in a low-temperature, low-humidity environment.

[0007] In other words, an object of the present disclosure is to provide a toner that can achieve stable cleaning properties and image quality even when a printer is used for a long period of time in a low-temperature, low-humidity environment using paper that generates a lot of paper dust, which leads to a decrease in cleaning properties of the photoreceptor surface. [Means for solving the problem]

[0008] That is, the present disclosure: A toner comprising toner particles containing a binder resin, and fatty acid metal salt particles and hydrotalcite particles on the surfaces of the toner particles, the hydrotalcite particles contain fluorine, In a line analysis of a STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, When the area ratio of the fatty acid metal salt particles to the toner particles in the EDS measurement field of view measured by STEM-EDS mapping analysis of the toner is S1 (%) and the area ratio of the hydrotalcite particles to the toner particles is H1 (%), The toner has an S1 / H1 ratio of 0.25 to 9.00. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a toner that can achieve stable cleaning properties and image quality even when using paper that generates a lot of paper dust, which leads to a decrease in cleaning properties of the photoreceptor surface, and when the printer is used for long periods of time in a low-temperature, low-humidity environment. [Brief explanation of the drawings]

[0010] [Figure 1] Schematic diagram of EDS line analysis in STEM-EDS mapping analysis DETAILED DESCRIPTION OF THE INVENTION

[0011] In the present disclosure, unless otherwise specified, the expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way. In the present disclosure, "(meth)acrylic" means "acrylic" and / or "methacrylic".

[0012] The present inventors have conducted extensive research into the reason why cleaning performance tends to decrease when a printer is used for a long period of time in a low-temperature, low-humidity environment using paper that generates a lot of paper dust. As a result, we found that when paper that generates a lot of paper dust is used in a low-temperature, low-humidity environment, the paper dust becomes strongly negative and is likely to migrate to the photoreceptor, and the electrostatic force causes it to adhere strongly to the photoreceptor, making it difficult to remove during the cleaning process.

[0013] In response to this, a certain degree of effect on cleaning performance was achieved by incorporating a cleaning aid such as a fatty acid metal salt into the toner. However, it was found that when the printer was used for a long period of time in a low-temperature, low-humidity environment using paper that generates a lot of paper dust, the cleaning performance of the paper dust was insufficient. Furthermore, it was found that when hydrotalcite particles used as microcarriers are added to the toner to enhance the charging characteristics of the toner, the effectiveness of cleaning aids such as fatty acid metal salts is impaired, further reducing the cleaning ability of paper dust in low-temperature, low-humidity environments.

[0014] The inventors speculate that the reason for this is as follows. Hydrotalcite particles are highly positive particles, and therefore become strongly positive in a low-temperature, low-humidity environment. The strongly positive hydrotalcite particles are transferred to the photoreceptor and supplied to the cleaning process, and in the cleaning process, the strongly positive hydrotalcite particles aggregate, involving the negative fatty acid metal salt. This reduces the dispersibility of the fatty acid metal salt in the cleaning process, which is thought to result in a decrease in cleaning performance.

[0015] The present inventors have conducted extensive research into toners that can achieve stable cleaning performance and image quality. As a result, they have discovered that by containing fluorine-containing hydrotalcite particles and fatty acid metal salt particles in a toner, and by controlling the ratio of the hydrotalcite particles to the fatty acid metal salt particles to fall within a certain range in a STEM-EDS analysis of the toner, the cleaning performance of paper dust can be dramatically improved when a printer is used for a long period of time in a low-temperature, low-humidity environment, and have completed the present disclosure.

[0016] The present disclosure provides: A toner comprising toner particles containing a binder resin, and fatty acid metal salt particles and hydrotalcite particles on the surfaces of the toner particles, the hydrotalcite particles contain fluorine, In a line analysis of a STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, When the area ratio of the fatty acid metal salt particles to the toner particles in the EDS measurement field of view measured by STEM-EDS mapping analysis of the toner is S1 (%) and the area ratio of the hydrotalcite particles to the toner particles is H1 (%), The toner has an S1 / H1 ratio of 0.25 to 9.00.

[0017] The reason why a toner having the above-described configuration can maintain stable cleaning performance even when using paper that generates a lot of paper dust and when the printer is used for long periods of time in a low-temperature, low-humidity environment is unclear, but the inventors speculate as follows.

[0018] The toner of the present disclosure contains toner particles containing a binder resin, and fatty acid metal salt particles and hydrotalcite particles on the surfaces of the toner particles. Specific preferred fatty acid gold salt particles and hydrotalcite particles will be described later. The hydrotalcite particles contain fluorine. Furthermore, line analysis in a STEM-EDS mapping analysis of the toner revealed that fluorine is present inside the hydrotalcite particles.

[0019] Hydrotalcite particles containing fluorine inside are particles that act as positive microcarriers, but unlike conventional hydrotalcite particles, they do not become excessively charged even when used in low-temperature, low-humidity environments, and are positive particles that can maintain an appropriate amount of charge. Therefore, even if the hydrotalcite particles are transferred from the toner to the photoreceptor and then supplied to the cleaning process, they do not cause aggregation of the fatty acid metal salt particles and can maintain good dispersibility.

[0020] Because both paper dust and fatty acid metal salt particles are negative, they are prone to electrostatic repulsion, making it difficult for the fatty acid metal salt to act on the paper dust, making it difficult to maintain the paper dust cleaning properties. In contrast, in the present disclosure, by supplying hydrotalcite particles to the cleaning process, the hydrotalcite particles, which have a moderate positive property, interact with the paper powder and fatty acid metal salt particles, which are negative, thereby dramatically improving the cleaning ability of the paper powder.

[0021] That is, in the present disclosure, the hydrotalcite particles adsorb negative paper dust, thereby reducing the image force between the paper dust and the photoreceptor, the presence of the hydrotalcite particles reduces the electrostatic repulsion between the paper dust and the fatty acid metal salt particles, and the fatty acid metal salt particles provide lubricant and release effects. It is believed that these effects work synergistically to dramatically improve cleaning performance.

[0022] In the present disclosure, the area ratio of fatty acid metal salt particles to toner particles in the EDS measurement field of view measured by STEM-EDS mapping analysis of the toner is defined as S1 (%), When the area ratio of the hydrotalcite particles to the toner particles is H1 (%), S1 / H1 is 0.25 to 9.00, and preferably S1 / H1 is 0.35 to 6.00. If the S1 / H1 ratio is less than 0.25, this means that the amount of fatty acid metal salt particles is very small compared to the amount of hydrotalcite particles, and the fatty acid metal salt particles will not be able to fully exert their cleaning effect, resulting in a decrease in the ability to clean paper dust. On the other hand, if the S1 / H1 ratio exceeds 9.00, the amount of fatty acid metal salt particles becomes much greater than the amount of hydrotalcite particles, and the effects of adsorbing paper dust by the hydrotalcite particles and reducing the electrostatic repulsion between the paper dust and the fatty acid metal salt particles become insufficient, resulting in a decrease in the ability to clean paper dust.

[0023] S1 / H1 can be controlled by the amount of fatty acid metal salt particles and hydrotalcite particles added to the toner particles. S1 / H1 can also be calculated by STEM-EDS mapping analysis of the toner, as described later.

[0024] Let H2 be the product of H1 and 100, which are the atomic concentration of fluorine in the hydrotalcite particles obtained from the main component mapping of the hydrotalcite particles by STEM-EDS mapping analysis of the toner, and S2 be the product of S1 and 100, which are the atomic concentration of metal atoms in the fatty acid metal salt particles obtained from the main component mapping of the fatty acid metal salt particles by STEM-EDS mapping analysis of the toner. H2 and S2 are indicators of the amount of fluorine atoms covering the toner particle surface and the amount of metal atoms covering the toner particle surface, respectively. H2 and S2 also indicate an indicator of the positive amount of the hydrotalcite particles and an indicator of the negative amount of the fatty acid metal salt particles, respectively. In this case, S2 / H2 is preferably 0.10 to 18.00, more preferably 0.19 to 16.00, even more preferably 0.23 to 9.00, and particularly preferably 0.56 to 6.30. When S2 / H2 is within the above range, hydrotalcite particles and fatty acid metal salt particles can be stably supplied to the cleaning step regardless of the image printing rate, and both particles can act effectively on paper dust in the cleaning section, improving cleaning performance.

[0025] When S2 / H2 is in the above range, stable cleaning properties can be exhibited regardless of the print rate of the image, even when the printer is used for long periods of time to print images with different print rates on the left and right. Specifically, this is preferable because halftone images with good uniformity can be output even after a test in which many images having white and black backgrounds on the left and right sides of the image are output. Furthermore, when S2 / H2 is in the above range, the negative property of the fatty acid metal salt particles and the positive property of the hydrotalcite particles are in the appropriate range, and the fatty acid metal salt particles and hydrotalcite particles in the toner are integrated and transferred to the photoreceptor more frequently. Therefore, even when an image has areas in which there is a difference in the photoreceptor potential, such as white areas (areas where the photoreceptor has a high negative potential and is relatively likely to attract positive particles) and black areas (areas where the photoreceptor has a low negative potential and is relatively likely to attract negative particles), and images with different printing rates are output, fatty acid metal salt particles and hydrotalcite particles can be stably supplied to the photoreceptor. As a result, the effect of the cleaning process on the printing rate can be reduced, and an image with highly uniform halftone image density can be obtained. S2 / H2 can be controlled by the amount of fluorine or metal atoms introduced, or the amount of hydrotalcite particles or fatty acid metal salt particles added.

[0026] When the number average particle diameter of the primary particles of the fatty acid metal salt particles is S3 (nm) and the number average particle diameter of the primary particles of the hydrotalcite particles is H3 (nm), it is preferable that S3>H3 be satisfied. I wish. When the relationship S3>H3 is satisfied, the hydrotalcite particles and the fatty acid metal salt particles are easily transferred from the toner to the photoreceptor as a unit. Therefore, in the cleaning process, fatty acid metal salt particles are dispersed on the wall surface of the cleaning member, and it becomes easier to form a state in which the fatty acid metal salt particles carry hydrotalcite particles, thereby increasing the hardness of the cleaning member, and as a result, good cleaning properties can be achieved even in an extremely low-temperature, low-humidity environment where toner is likely to pass through. S3 and H3 can be controlled by the methods described below.

[0027] The hydrotalcite particles used in the present disclosure will be described below. The hydrotalcite particles contain fluorine. Whether or not the hydrotalcite particles contain fluorine can be confirmed by STEM-EDS mapping analysis of the toner. Furthermore, in line analysis of the toner in STEM-EDS mapping analysis, fluorine is present inside the hydrotalcite particles. Specifically, this means that EDS line analysis is performed in the normal direction to the outer periphery of a fluorine-containing hydrotalcite particle, and fluorine present inside the particle is detected. The detection of fluorine inside the hydrotalcite particles by the above analysis indicates that fluorine is intercalated between the layers of the hydrotalcite particles.

[0028] The presence of fluorine inside the hydrotalcite particles prevents the hydrotalcite particles from charging up even in a low-temperature, low-humidity environment, and allows the particles to maintain a moderate amount of positive charge, thereby achieving the above-mentioned excellent cleaning properties. It is believed that the reason why hydrotalcite particles can maintain an appropriate amount of positive charge is that the presence of fluorine, which has a strong negative tendency, inside the hydrotalcite particles allows the positive charge on the surface of the hydrotalcite particles to be absorbed into the particles and neutralized, thereby suppressing charge buildup on the particle surface. It is preferable that fluorine is introduced into the interior of the hydrotalcite particles by introducing fluoride ions between the layers (intercalation) through anion exchange.

[0029] The fluorine atom concentration in the hydrotalcite particles is not particularly limited, but is preferably 0.01 atomic % to 5.00 atomic %, more preferably 0.04 atomic % to 3.00 atomic %, and even more preferably 0.09 atomic % to 2.00 atomic %. This range ensures that the hydrotalcite particles have an appropriate positive characteristic and the microcarrier properties are within an appropriate range. As a result, even in an extremely low-temperature, low-humidity environment where toner tends to be highly charged, toner is less likely to slip through during the cleaning process, and good cleaning properties can be achieved, which is preferable. The fluorine atom concentration in the hydrotalcite particles can be controlled by adjusting the fluorine concentration during hydrotalcite production. For example, it can be controlled by adjusting the amount of sodium fluoride added. In addition, the fluorine atom concentration in the hydrotalcite particles can be obtained from the main component mapping of the hydrotalcite particles by STEM-EDS mapping analysis of the toner.

[0030] The ratio of the atomic concentration of fluorine to aluminum in the hydrotalcite particles, F / Al (element ratio), obtained from the main component mapping of the hydrotalcite particles by STEM-EDS mapping analysis of the toner, is preferably 0.01 to 0.70, more preferably 0.02 to 0.65, even more preferably 0.03 to 0.60, and particularly preferably 0.04 to 0.32. When the content is in this range, the paper dust cleaning property is improved, the charging stability of the toner is improved in a low-temperature, low-humidity environment, and the occurrence of fogging in non-image areas during long-term use can be suppressed.

[0031] Specifically, when F / Al is 0.01 or more, the surface charge distribution of the hydrotalcite particles can be made uniform, improving the charge stability of the toner, thereby suppressing the occurrence of fogging in non-image areas during long-term use. Furthermore, by making the F / Al ratio 0.70 or less, excessive neutralization of the surface charge of the hydrotalcite particles is prevented, the time stability of the positive charge is improved, and the charge stability of the toner is improved, which results in suppressing fogging of non-image areas during long-term use.

[0032] The ratio of the atomic concentration of magnesium to aluminum in the hydrotalcite particles, Mg / Al (element ratio), obtained from main component mapping of the hydrotalcite particles A by STEM-EDS mapping analysis of the toner, is preferably 1.5 to 4.0, and more preferably 1.6 to 3.8. Mg / Al can be controlled by adjusting the amount of raw materials during the production of hydrotalcite. The atomic concentration of magnesium is preferably 0.20 atomic% to 1.00 atomic%, more preferably 0.50 atomic% to 0.80 atomic%.

[0033] Hydrotalcite particles can be those represented by the following compositional formula (1). M , - y M 3+ x (OH)2A n- (x / n) ·mH2O Formula (1) The above M 2+ , and M 3+ each represent a divalent and trivalent metal respectively. The hydrotalcite particles may be a solid solution containing a plurality of different elements. Also, a trace amount of a monovalent metal may be contained. However, it is preferable that 0 < x ≦ 0.5, y = 1 - x, and m ≧ 0. M 2+ is preferably at least one divalent metal ion selected from the group consisting of Mg, Zn, Ca, Ba, Ni, Sr, Cu, and Fe. M 3+ is preferably at least one trivalent metal ion selected from the group consisting of Al, B, Ga, Fe, Co, and In. A n- is an n-valent anion and contains at least F​​​​​​​​​​​​​​​​​​​​​​​​​​​Preferably, it is aluminum. Further, the hydrotalcite particles of the present disclosure preferably contain aluminum and magnesium. Specific compositional formulas include Mg 8.6 Al4(OH) 25.2 F2CO3·mH2O, Mg 12 Al4(OH) 32 F2CO3·mH2O and the like.

[0035] Further, the hydrotalcite particles preferably have water in their molecules, and in formula (1), it is more preferable that 0.1 < m < 0.6.

[0036] The number average particle diameter H3 of the primary particles of the hydrotalcite particles is preferably 40 nm to 1100 nm, more preferably 50 nm to 1000 nm, and even more preferably 60 nm to 800 nm. When the number average particle diameter of the hydrotalcite particles is within the above range, the charging rise property of the toner becomes good, it becomes easy to sharpen the charge distribution of the toner, and the halftone reproducibility in a low temperature and low humidity environment becomes good. The above particle diameter can be measured using known means such as a scanning electron microscope. Further, the above particle diameter can be controlled by controlling the conditions of the reaction step, pulverization step, centrifugation step, classification step, and sieving step in the production process of the hydrotalcite particles.

[0037] The hydrotalcite particles may be hydrophobically treated with a surface treatment agent. The surface treatment As the agent, higher fatty acids, coupling agents, esters, oils such as silicone oil can be used. Among them, higher fatty acids are preferably used, and specifically, stearic acid, oleic acid, and lauric acid are exemplified.

[0038] The content of hydrotalcite particles in the toner is not particularly limited, but is preferably 0.01 to 3.00 parts by mass, more preferably 0.05 to 0.50 parts by mass, and even more preferably 0.05 to 0.30 parts by mass, relative to 100 parts by mass of toner particles. The content of hydrotalcite particles can be quantified using fluorescent X-ray analysis and a calibration curve prepared from a standard sample.

[0039] The area ratio H1 (%) of hydrotalcite particles to toner particles in the EDS measurement field of view, as measured by STEM-EDS mapping analysis of the toner, is preferably 0.05 to 0.50, more preferably 0.07 to 0.41, and even more preferably 0.14 to 0.33. The area ratio represents the proportion of hydrotalcite particles present in the toner particles. Within this range, the effects of the hydrotalcite particles are easily obtained. The area ratio can be controlled by changing the amount of the hydrotalcite particles added to the toner particles.

[0040] Next, the fatty acid metal salt particles used in the present disclosure will be described. The fatty acid metal salt particles are preferably salts of at least one metal selected from the group consisting of zinc, calcium, magnesium, aluminum, and lithium, and more preferably fatty acid zinc salts, which provide better cleaning properties in extremely low-temperature, low-humidity environments.

[0041] The fatty acid of the fatty acid metal salt particles is preferably a higher fatty acid having 8 to 28 carbon atoms (more preferably 12 to 22). The metal is preferably a polyvalent metal having a valence of 2 or more. That is, the fatty acid metal salt particles are preferably a fatty acid metal salt of a polyvalent metal having a valence of 2 or more (more preferably divalent or trivalent, and even more preferably divalent) and a fatty acid having 8 to 28 carbon atoms (more preferably 12 to 22). Use of a fatty acid having 8 or more carbon atoms is preferred because the melting point of the fatty acid metal salt is appropriately high, contamination of charging members such as a developing blade is suppressed, and fogging after endurance and charge build-up are improved. On the other hand, if the number of carbon atoms in the fatty acid is 28 or less, the melting point of the fatty acid metal salt particles will not be too high, and the fixability will not be impaired. As the fatty acid, stearic acid is particularly preferred. The divalent or higher polyvalent metal preferably includes zinc. Examples of fatty acid metal salt particles include metal stearates such as zinc stearate, calcium stearate, magnesium stearate, aluminum stearate, and lithium stearate, and zinc laurate.

[0042] The number average particle size S3 of the primary particles of the fatty acid metal salt particles is preferably 350 nm to 1100 nm, and more preferably 400 nm to 1000 nm. When the number average particle size of the primary particles of the fatty acid metal salt particles is within the above range, the cleaning properties in a low-temperature, low-humidity environment are further improved. The particle size can be measured using a known means such as a scanning electron microscope, and can be controlled by controlling the conditions of the reaction step, pulverization step, centrifugation step, classification step, and sieving step in the production process of the fatty acid metal salt particles.

[0043] The content of the fatty acid metal salt particles is not particularly limited, but is preferably 100 parts by mass of the toner particles. The content of the fatty acid metal salt particles is preferably 0.01 to 0.40 parts by mass, more preferably 0.05 to 0.30 parts by mass, and even more preferably 0.10 to 0.20 parts by mass. The content of the fatty acid metal salt particles can be quantified by fluorescent X-ray analysis using a calibration curve prepared from a standard sample. By setting the content within the above range, cleaning properties and halftone reproducibility in a low-temperature, low-humidity environment are further improved.

[0044] The atomic concentration of metal atoms in the fatty acid metal salt particles is not particularly limited, but is preferably 0.10 atomic % to 3.00 atomic %, more preferably 0.20 atomic % to 2.00 atomic %, and even more preferably 0.30 atomic % to 1.00 atomic %. Within this range, the negative properties of the fatty acid metal salt particles become appropriate, and the repulsive force with paper dust is kept within an appropriate range, thereby improving cleaning properties in low-temperature, low-humidity environments. The atomic concentration of metal atoms in fatty acid metal salt particles can be controlled by adjusting the concentration of metal atoms during production of the fatty acid metal salt particles, and can also be obtained from major component mapping of fatty acid metal salt particles by STEM-EDS mapping analysis of the toner.

[0045] The area ratio S1 (%) of fatty acid metal salt particles to toner particles in the EDS measurement field of view, as measured by STEM-EDS mapping analysis of the toner, is preferably 0.05 to 0.70, more preferably 0.10 to 0.60, and even more preferably 0.20 to 0.40. The above area ratio represents the proportion of fatty acid metal salt particles to toner particles. Within this range, the effects of the fatty acid metal salt particles are easily obtained. The above area ratio can be controlled by the amount of fatty acid metal salt particles added to the toner particles.

[0046] Each component constituting the toner and the method for producing the toner will be described in more detail below.

[0047] <Toner particles> The toner particles contain a binder resin. Furthermore, the toner particles preferably have a core-shell structure having a core containing resin A and a shell containing resin B. In the present disclosure, the toner particles having a core-shell structure means that the surfaces of the toner particles are coated with a resin component different from the wax component. The presence or absence of the core-shell structure can be confirmed by observing the cross section of the toner with a transmission electron microscope (TEM). By having the toner particles have a core-shell structure, it is possible to prevent the hydrotalcite particles and fatty acid metal salt particles from becoming embedded in the toner particles during long-term use, making it easier to steadily transfer the hydrotalcite particles and fatty acid metal salt particles to the photoreceptor and supply them to the cleaning unit.

[0048] The thickness of the shell layer may be thinner or thicker than 0.1 μm. The thickness of the shell layer is preferably 0.1 μm or less, more preferably 50 nm or less, and preferably 1 nm or more. An example of a method for analyzing the thickness of the shell layer is shown below.

[0049] Measurement by time-of-flight secondary ion mass spectrometry: When a depth profile measurement is performed, the shell thickness is the depth at which the ratio of the signal originating from the shell to the signal originating from the core is 1:1. The shell thickness can be controlled by the amount of raw materials added to the shell during the production of toner particles.

[0050] <Binder resin> The core contains resin A as a binder resin. Examples of resin A include polyester resins and vinyl resins, and other binder resins such as the following resins or polymers: styrene-acrylic resin, polyester resin, epoxy resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, and mixed or composite resins thereof. Resin A is preferably a polyester resin, a styrene-acrylic resin, or a hybrid resin thereof, and more preferably a polyester resin or a styrene-acrylic resin, because they are inexpensive, easily available, and have excellent low-temperature fixing properties. When the toner particles do not have a core-shell structure, the resins described above as resin A can be suitably used.

[0051] The polyester resin can be obtained by selecting and combining suitable compounds from polycarboxylic acids, polyols, hydroxycarboxylic acids, etc., and synthesizing them using a conventionally known method such as transesterification or polycondensation.

[0052] Polycarboxylic acids are compounds containing two or more carboxy groups in one molecule, and among these, dicarboxylic acids are compounds containing two carboxy groups in one molecule and are preferably used.

[0053] Examples of dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-carboxylic acid, hexahydroterephthalic acid, malonic acid, pimelic acid, suberic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediacetic acid, o-phenylenediacetic acid, diphenylacetic acid, diphenyl-p,p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracenedicarboxylic acid, and cyclohexanedicarboxylic acid.

[0054] Examples of polycarboxylic acids other than dicarboxylic acids include trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, pyrenetetracarboxylic acid, itaconic acid, glutaconic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid, isododecenylsuccinic acid, n-octylsuccinic acid, n-octenylsuccinic acid, etc. These may be used alone or in combination of two or more.

[0055] Polyols are compounds containing two or more hydroxyl groups in one molecule, and among these, diols are compounds containing two hydroxyl groups in one molecule and are preferably used. Specifically, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1 ,18-Octadecanediol, 1,14-Eicosanedecanediol, Diethylene glycol, Triethylene glycol, Dipropylene glycol, Polyethylene glycol, Polypropylene glycol, Polytetramethylene ether glycol, 1,4-Cyclohexanediol, 1,4-Cyclohexanedimethanol, 1,4-Butenediol, Neopentyl glycol, 1,4-Cyclohexanediol, Polytetramethylene glycol, Hydrogenated bisphenol A, Bisphenol Examples of suitable bisphenols include bisphenol A, bisphenol F, bisphenol S, and alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above bisphenols.

[0056] Among these, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferred, and alkylene oxide adducts of bisphenols and their combined use with alkylene glycols having 2 to 12 carbon atoms are particularly preferred.

[0057] Examples of trivalent or higher polyols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, hexamethylolmelamine, hexaethylolmelamine, tetramethylolbenzoguanamine, tetraethylolbenzoguanamine, sorbitol, trisphenol PA, phenol novolac, cresol novolac, and alkylene oxide adducts of the above trivalent or higher polyphenols. These may be used alone or in combination of two or more. The polyester resin may also be a polyester resin containing a urea group. It is preferable that the carboxyl groups of the polyester resin, such as terminal groups, are not capped.

[0058] Examples of the styrene-acrylic resin include homopolymers made of the following polymerizable monomers, copolymers obtained by combining two or more of these, and mixtures thereof. Styrenic monomers such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene and p-phenylstyrene; (meth)acrylic monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-amyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, dimethyl phosphate ethyl (meth)acrylate, diethyl phosphate ethyl (meth)acrylate, dibutyl phosphate ethyl (meth)acrylate, and 2-benzoyloxyethyl (meth)acrylate, (meth)acrylonitrile, 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid, and maleic acid; vinyl ether monomers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketone monomers such as vinyl methyl ketone, vinyl ethyl ketone, and vinyl isopropenyl ketone; Polyolefins such as ethylene, propylene, and butadiene.

[0059] The styrene-acrylic resin may contain a polyfunctional polymerizable monomer, if necessary. Examples of the polyfunctional polymerizable monomer include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2'-bis(4-((meth)acryloxydiethoxy)phenyl)propane, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, divinylbenzene, divinylnaphthalene, and divinylate. Teru and others. In order to control the degree of polymerization, it is also possible to further add a known chain transfer agent and polymerization inhibitor.

[0060] Examples of the polymerization initiator for obtaining the styrene-acrylic resin include organic peroxide-based initiators and azo-based polymerization initiators. Examples of organic peroxide initiators include benzoyl peroxide, lauroyl peroxide, di-α-cumyl peroxide, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, bis(4-t-butylcyclohexyl)peroxydicarbonate, 1,1-bis(t-butylperoxy)cyclododecane, t-butylperoxymaleic acid, bis(t-butylperoxy)isophthalate, methyl ethyl ketone peroxide, tert-butylperoxy-2-ethylhexanoate, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and tert-butylperoxypivalate.

[0061] Examples of the azo polymerization initiator include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobismethylbutyronitrile, and 2,2'-azobis-(methyl isobutyrate).

[0062] Furthermore, a redox initiator, which is a combination of an oxidizing substance and a reducing substance, can also be used as the polymerization initiator. The oxidizing substances include inorganic peroxides such as hydrogen peroxide, persulfates (sodium, potassium and ammonium salts) and oxidizing metal salts such as tetravalent cerium salts. Examples of reducing substances include reducing metal salts (divalent iron salts, monovalent copper salts, and trivalent chromium salts), ammonia, lower amines (amines having about 1 to 6 carbon atoms such as methylamine and ethylamine), amino compounds such as hydroxylamine, reducing sulfur compounds such as sodium thiosulfate, sodium hydrosulfite, sodium hydrogensulfite, sodium sulfite, and sodium formaldehyde sulfoxylate, lower alcohols (having 1 to 6 carbon atoms), ascorbic acid or a salt thereof, and lower aldehydes (having 1 to 6 carbon atoms).

[0063] The polymerization initiator is selected with reference to its 10-hour half-life temperature and is used alone or in combination. The amount of polymerization initiator added varies depending on the desired degree of polymerization, but is generally 0.5 to 20.0 parts by mass per 100.0 parts by mass of polymerizable monomer.

[0064] Resin A may also contain a crystalline polyester. Examples of the crystalline polyester include a condensation polymer of an aliphatic diol and an aliphatic dicarboxylic acid. It is preferably a condensation polymer of an aliphatic diol having 2 to 12 carbon atoms and an aliphatic dicarboxylic acid having 2 to 12 carbon atoms. Examples of the aliphatic diol having 2 to 12 carbon atoms include the following compounds: 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0065] Aliphatic diols having a double bond can also be used, such as 2-butene-1,4-diol, 3-hexene-1,6-diol, and 4-octene-1,8-diol.

[0066] Examples of the aliphatic dicarboxylic acid having 2 to 12 carbon atoms include the following compounds. Oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, lower alkyl esters and acid anhydrides of these aliphatic dicarboxylic acids.

[0067] Among these, sebacic acid, adipic acid, 1,10-decanedicarboxylic acid, and lower alkyl esters and acid anhydrides thereof are preferred. These may be used alone or in combination of two or more.

[0068] Aromatic dicarboxylic acids can also be used. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4'-biphenyldicarboxylic acid. Among these, terephthalic acid is preferred because it is easily available and can easily form a polymer with a low melting point.

[0069] Furthermore, dicarboxylic acids having a double bond can also be used, which can be suitably used to suppress hot offset during fixing, since the double bond can be utilized to crosslink the entire resin. Examples of such dicarboxylic acids include fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Also included are lower alkyl esters and acid anhydrides of these acids. Among these, fumaric acid and maleic acid are more preferred.

[0070] The method for producing the crystalline polyester is not particularly limited, and the crystalline polyester can be produced by a general polyester polymerization method in which a dicarboxylic acid component and a diol component are reacted. For example, the crystalline polyester can be produced by a direct polycondensation method or an ester exchange method, which are selected depending on the type of monomer.

[0071] The content of the crystalline polyester is 1.0 to 3 parts by mass relative to 100 parts by mass of the binder resin. The content is preferably 0.0 parts by mass, and more preferably 3.0 to 25.0 parts by mass.

[0072] The peak temperature of the maximum endothermic peak of the crystalline polyester measured using a differential scanning calorimeter (DSC) is preferably 50.0°C to 100.0°C, and more preferably 50.0°C to 90.0°C from the viewpoint of low-temperature fixability.

[0073] The molecular weight of resin A is preferably a peak molecular weight Mp of 5,000 to 100,000, more preferably 10,000 to 40,000. The glass transition temperature Tg of resin A is preferably 40°C to 70°C, more preferably 40°C to 60°C. The content of resin A is preferably 50% by mass or more relative to the total amount of resin components in the toner particles. Furthermore, the content of resin A in the binder resin is preferably 50% by mass to 100% by mass.

[0074] The shell contains resin B. Examples of resin B include polyester resins, vinyl resins, and other binder resins, which are similar to the materials described above for resin A. Resin B is preferably a polyester resin, a styrene-acrylic resin, or a hybrid resin thereof, and more preferably a polyester resin or a styrene-acrylic resin, because they are inexpensive, easily available, and have excellent low-temperature fixing properties.

[0075] Resin B may be the same or different from resin A. For example, styrene-acrylic resins may be used as resin A and resin B, polyester resins may be used as resin A and resin B, or a styrene-acrylic resin may be used as resin A and resin B. As B, a polyester resin can be used. Preferably, resin A contains a styrene-acrylic resin, and resin B contains a styrene-acrylic resin. Also, preferably, resin A contains a polyester resin, and resin B contains a polyester resin. Also, preferably, resin A contains a styrene-acrylic resin, and resin B contains a polyester resin. The molecular weight of Resin B, Mp, is preferably 5,000 to 100,000, and more preferably 15,000 to 80,000.

[0076] The glass transition temperature Tg of resin B is preferably 50° C. to 100° C., more preferably 55° C. to 80° C., and even more preferably 60° C. to 80° C. From the viewpoint of suppressing embedding of hydrotalcite particles A in toner particles during fixing, it is preferable to select a material for resin B having a higher Tg than resin A. The content of Resin B is preferably 1% by mass to 30% by mass with respect to the total amount of resin components in the toner particles.

[0077] <Crosslinking agent> In order to control the molecular weight of the binder resin constituting the toner particles, a crosslinking agent may be added during polymerization of the polymerizable monomer. For example, ethylene glycol 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, and #600 diacrylates, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester diacrylate (MANDA Nippon Kayaku), and the above acrylates can be methacrylated. Something that has been changed to Related. The amount of the crosslinking agent added is preferably 0.001 to 15,000 parts by mass relative to 100 parts by mass of the polymerizable monomer.

[0078] <Release agent> The toner may contain a known wax as a release agent. Specific examples include petroleum waxes such as paraffin wax, microcrystalline wax, and petrolatum and their derivatives, montan wax and its derivatives, hydrocarbon waxes produced by the Fischer-Tropsch process and their derivatives, polyolefin waxes such as polyethylene and polypropylene and their derivatives, and natural waxes such as carnauba wax and candelilla wax and their derivatives. Derivatives also include oxides, block copolymers with vinyl monomers, and graft-modified products. Other examples include alcohols such as higher aliphatic alcohols, fatty acids such as stearic acid and palmitic acid or their acid amides, esters, and ketones, hydrogenated castor oil and its derivatives, vegetable waxes, and animal waxes.These may be used alone or in combination.

[0079] Among these, the use of hydrocarbon wax or ester wax tends to improve the developing property and fixing property, and is therefore preferred. That is, the wax preferably contains hydrocarbon wax or ester wax. Note that these waxes may contain an antioxidant to the extent that it does not affect the properties of the toner. In addition, from the viewpoint of phase separation property with respect to the binder resin or crystallization temperature, preferred examples include higher fatty acid esters such as behenyl behenate and dibehenyl sebacate. Furthermore, ester waxes as plasticizers, which will be described later, can also be preferably used.

[0080] The content of the release agent is preferably 1.0 to 30.0 parts by mass with respect to 100.0 parts by mass of the binder resin. The melting point of the release agent is preferably 30° C. to 120° C., and more preferably 60° C. to 100° C. By using a release agent with a melting point of 30° C. to 120° C., the release effect is efficiently exerted and a wider fixing area is ensured.

[0081] <Plasticizer> In order to improve the sharp melting property of the toner, it is preferable to use a crystalline plasticizer. The plasticizer is not particularly limited, and known plasticizers used in toners such as those described below can be used. Esters of monohydric alcohols and fatty carboxylic acids, or esters of monohydric carboxylic acids and fatty alcohols, such as behenyl behenate, stearyl stearate, and palmityl palmitate; esters of dihydric alcohols and fatty carboxylic acids, or esters of dihydric carboxylic acids and fatty alcohols, such as ethylene glycol distearate, dibehenyl sebacate, and hexanediol dibehenate; esters of trihydric alcohols and fatty carboxylic acids, or esters of trihydric carboxylic acids and fatty alcohols, such as glycerin tribehenate; pentaerythritol tetrastearate esters of tetrahydric alcohols and aliphatic carboxylic acids, such as dipentaerythritol hexastearate and dipentaerythritol hexapalmitate, or esters of tetrahydric carboxylic acids and aliphatic alcohols; esters of hexahydric alcohols and aliphatic carboxylic acids, such as dipentaerythritol hexastearate and dipentaerythritol hexapalmitate, or esters of hexahydric carboxylic acids and aliphatic alcohols; esters of polyhydric alcohols and aliphatic carboxylic acids, such as polyglycerol behenate, or esters of polyhydric carboxylic acids and aliphatic alcohols; and natural ester waxes, such as carnauba wax and rice wax. These may be used alone or in combination.

[0082] <Coloring agent> The toner particles may contain a colorant. Known pigments and dyes can be used as the colorant. Pigments are preferred as the colorant because they have excellent weather resistance. Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds. Specific examples include: CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62 and 66. Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specific examples include CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221 and 254, and CI Pigment Violet 19.

[0083] Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specific examples include the following: CI Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185, 191 and 194. Examples of black colorants include those toned to black using the above yellow, magenta, and cyan colorants, as well as carbon black. These colorants can be used alone or in mixture, or further in the state of a solid solution. The colorant is preferably used in an amount of 1.0 to 20.0 parts by mass with respect to 100.0 parts by mass of the binder resin.

[0084] <Charge control agents and charge control resins> The toner particles may contain a charge control agent or a charge control resin. Known charge control agents can be used, and charge control agents that have a high triboelectric charging speed and can stably maintain a constant triboelectric charge amount are particularly preferred. Furthermore, when the toner particles are produced by a suspension polymerization method, charge control agents that have low polymerization inhibition properties and are substantially free of solubilized substances in aqueous media are particularly preferred.

[0085] Examples of substances that control the toner to be negatively charged include 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, calixarene, and charge control resins.

[0086] Examples of the charge control resin include polymers or copolymers having sulfonic acid groups, sulfonate salt groups, or sulfonate ester groups. As the polymer having sulfonic acid groups, sulfonate salt groups, or sulfonate ester groups, a polymer containing 2% by mass or more, more preferably 5% by mass or more, of a sulfonate group-containing acrylamide monomer or a sulfonate group-containing methacrylamide monomer in copolymerization ratio is preferred.

[0087] The charge control resin preferably has a glass transition temperature (Tg) of 35°C to 90°C, a peak molecular weight (Mp) of 10,000 to 30,000, and a weight average molecular weight (Mw) of 25,000 to 50,000. When used, it can impart desirable triboelectric charging properties without affecting the thermal properties required of the toner particles. Furthermore, when the charge control resin contains a sulfonic acid group, the dispersibility of the charge control resin itself in the polymerizable monomer composition and the dispersibility of colorants and the like are improved, resulting in further improvements in coloring power, transparency, and triboelectric charging properties. These charge control agents or charge control resins may be added singly or in combination of two or more kinds. The amount of the charge control agent or charge control resin added 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 binder resin.

[0088] From the viewpoint of achieving good charge buildup in a low-temperature, low-humidity environment, the toner particles preferably contain at least one polyvalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron, and more preferably contain aluminum. By containing a polyvalent metal element in the toner particles, the charge on the toner particle surface can be accumulated inside the toner particles, making it difficult for the charge characteristics of the toner to fluctuate even during long-term use. Therefore, even in a low-temperature, low-humidity environment where the absolute moisture content is particularly low and which is an environment that is severe on the toner charge distribution, the hydrotalcite particles and fatty acid metal salt particles can be stably transferred to the photoreceptor and supplied to the cleaning section, thereby achieving stable paper dust cleaning performance.

[0089] The content (atomic concentration) of polyvalent metal elements in toner particles is preferably 0.01 to 0.09, and more preferably 0.01 to 0.06, when the atomic concentration of carbon in toner particles is taken as 100. The content of polyvalent metal elements in toner particles can be measured from the main component mapping of the toner particles by STEM-EDS mapping analysis, which will be described later. By keeping the content within the above range, the charge build-up property in a low-temperature, low-humidity environment is improved.

[0090] There is no particular restriction on the means for making the polyvalent metal element present inside the toner particles. For example, when toner particles are produced by a pulverization method, the polyvalent metal element may be incorporated into the raw material resin in advance, or the polyvalent metal element may be added when the raw materials are melted and kneaded, so that the polyvalent metal element is incorporated into the toner particles. When toner particles are produced by a wet production method such as a suspension polymerization method or an emulsion aggregation method, the polyvalent metal element may be incorporated into the raw materials, or the polyvalent metal element may be added via an aqueous medium during the production process.

[0091] In emulsion aggregation, metal ions may be added as a flocculant. In this case, the metal elements can be ionized in an aqueous medium and then incorporated into the toner particles, which is preferable from the viewpoint of uniformity. Furthermore, in emulsion aggregation toner, carboxy groups may be present in the molecular chains constituting the binder resin. The metal ions added as a flocculant coordinate with the carboxy groups, thereby forming excellent conductive paths in the resin particles. Furthermore, trivalent aluminum can coordinate with carboxy groups in smaller amounts than divalent magnesium and calcium, or iron, which can assume mixed valences, and therefore tends to achieve better charging characteristics. Preferably, the resin A has a carboxy group. There are no particular limitations on the means for incorporating a carboxy group into the resin A. When the resin A is a styrene-acrylic resin, a monomer having a carboxy group, such as (meth)acrylic acid, may be used.

[0092] <Method of manufacturing toner particles> The method for producing toner particles is not particularly limited, and known means can be used, such as a kneading and pulverization method or a wet production method. From the viewpoints of uniform particle size, shape controllability, and ease of obtaining toner particles with a core-shell structure, a wet production method is preferred. Examples of wet production methods include a suspension polymerization method, a solution suspension method, an emulsion polymerization aggregation method, and an emulsion aggregation method, and from the viewpoint of dispersing the polyvalent metal element on the surface of the toner particles and inside the toner particles, an emulsion aggregation method is more preferred.

[0093] In the emulsion aggregation method, first, a dispersion of each material, such as binder resin particles and colorant, is prepared. The resulting dispersion of each material is dispersed and mixed, with the addition of a dispersion stabilizer as needed. Then, an aggregating agent is added to aggregate the particles to the desired toner particle size, and then, or simultaneously with the aggregation, the resin particles are fused together. If necessary, the shape is controlled by heat to form toner particles.

[0094] Here, the binder resin microparticles can also be composite particles formed of two or more layers composed of resins with different compositions. For example, they can be produced by emulsion polymerization, miniemulsion polymerization, phase inversion emulsification, or a combination of several production methods. When an internal additive is contained in the toner particles, the internal additive may be contained in the resin microparticles. Alternatively, a dispersion of internal additive microparticles consisting only of the internal additive may be separately prepared, and the internal additive microparticles may be aggregated together with the resin microparticles when aggregating them. Furthermore, toner particles with layered compositions can be produced by adding resin microparticles with different compositions at different times during aggregation. After aggregating resin microparticles containing resin A to form a core portion, resin microparticles containing shell resin B can be added at different times and aggregated to form a shell portion.

[0095] Specifically, the method includes a shell formation step in which aggregated particles (core particles) containing resin A are formed in an aggregation step, and then resin fine particles containing shell resin B are further added and aggregated to form a shell. Shell resin B may have the same composition as core resin A, or a resin with a different composition may be used. The amount of shell resin added is preferably 1.0 to 10.0 parts by mass, and more preferably 2.0 to 7.0 parts by mass, per 100 parts by mass of the binder resin contained in the core particles.

[0096] In this case, the method for producing the toner preferably includes the following steps. (1) a dispersion step for preparing a dispersion of binder resin particles containing a binder resin such as resin A; (2) an aggregation step of aggregating the binder resin fine particles contained in the binder resin fine particle dispersion to form aggregates; (3) a shell formation step in which resin fine particles containing a shell resin B are further added to the dispersion containing the aggregates to aggregate them, thereby forming aggregates having a shell; and (4) a fusion step of heating and fusing the aggregates

[0097] In addition, during the step (4) or after the steps (1) to (4), the following step (5) may be carried out: (5) A spheronization step in which the agglomerates are heated at a higher temperature. It is preferred that the compound has the following structure: Then, after the step (5), the following steps (6) and (7) are carried out: (6) a cooling step of cooling the aggregate at a cooling rate of 0.1°C / sec or more; (7) an annealing step of heating and maintaining the temperature at or above the crystallization temperature or glass transition temperature of the binder resin after the cooling step; It is more preferable that the .alpha.-hydroxybenzoate has the following structure:

[0098] The following can be used as the dispersion stabilizer. As the surfactant, known cationic surfactants, anionic surfactants, and nonionic surfactants can be used. Examples of inorganic dispersion stabilizers include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. Examples of organic dispersion stabilizers include polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch.

[0099] As the aggregating agent, in addition to surfactants having a polarity opposite to that of the surfactants used in the dispersion stabilizer described above, inorganic salts and inorganic metal salts having a valence of two or more can be suitably used. In particular, inorganic metal salts are preferred because they ionize polyvalent metal elements in an aqueous medium, making it easy to control aggregating properties and toner chargeability. Specific examples of preferred inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, iron chloride, aluminum chloride, and aluminum sulfate, as well as inorganic metal salt polymers such as polyiron chloride, polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Among these, aluminum salts and their polymers are particularly preferred. In general, to obtain a sharper particle size distribution, the valence of the inorganic metal salt is preferably divalent rather than monovalent, and more preferably trivalent or higher rather than divalent. Furthermore, even if the valence is the same, inorganic metal salt polymers are more suitable. From the viewpoint of high definition and high resolution of images, the volume-based median diameter of the toner particles is preferably 3.0 μm to 10.0 μm.

[0100] <Toner manufacturing method> The toner contains hydrotalcite particles and fatty acid metal salt particles as external additives. Other external additives may be added as needed. In this case, the total content of external additives, such as inorganic and organic fine particles including hydrotalcite particles and fatty acid metal salt particles, is preferably 0.50 to 5.00 parts by mass per 100 parts by mass of toner particles.

[0101] The mixer for externally adding the external additive to the toner particles is not particularly limited, and any known mixer, whether dry or wet, can be used. Examples include FM Mixer (manufactured by Nippon Coke & Engineering Co., Ltd.), Super Mixer (manufactured by Kawata Corporation), Nobilta (manufactured by Hosokawa Micron Corporation), and Hybridizer (manufactured by Nara Kikai Co., Ltd.). To control the coating state of the external additive, the toner can be prepared by adjusting the rotation speed, processing time, and water temperature and amount in the jacket of the external addition device.

[0102] In addition, examples of sieving devices used to sift out coarse particles after external addition include Ultrasonic (manufactured by Koei Sangyo Co., Ltd.); Resonaseave, Gyrosifter (Tokuju Kogyo Co., Ltd.); Vibrasonic System (manufactured by Dalton Co., Ltd.); Soniclean (manufactured by Shinto Kogyo Co., Ltd.); Turbo Screener (manufactured by Turbo Kogyo Co., Ltd.); and Microsifter (manufactured by Makino Sangyo Co., Ltd.).

[0103] The methods for measuring the physical properties of the toner and each material will be described below. <Method for identifying hydrotalcite particles and fatty acid metal salt particles> The external additives, hydrotalcite particles and fatty acid metal salt particles, can be identified by a combination of shape observation using a scanning electron microscope (SEM) and elemental analysis using energy dispersive X-ray analysis (EDS). Using a scanning electron microscope "S-4800" (product name; manufactured by Hitachi, Ltd.), the toner is observed at a magnification of up to 50,000 times. The focus is set on the surface of the toner particles, and the external additive to be identified is observed. EDS analysis of the external additive to be identified is performed, and the hydrotalcite particles and fatty acid metal salt particles can be identified from the type of element peak. When element peaks observed include an element peak of at least one metal selected from the group consisting of Mg, Zn, Ca, Ba, Ni, Sr, Cu, and Fe, which are metals that can constitute hydrotalcite particles, and an element peak of at least one metal selected from the group consisting of Al, B, Ga, Fe, Co, and In, the presence of hydrotalcite particles containing the two types of metals can be inferred. Similarly, when the element peaks observed are at least one metal selected from the group consisting of Zn, Ca, Mg, Al, and Li, which are metals that constitute fatty acid metal salt particles, and a carbon element peak, the presence of fatty acid metal salt particles can be inferred. Samples of the hydrotalcite particles and fatty acid metal salt particles inferred by EDS analysis are separately prepared, and their shapes are observed by SEM and analyzed by EDS. The analysis results of the samples are compared to the analysis results of the particles to be identified to determine whether they are hydrotalcite particles or fatty acid metal salt particles.

[0104] <Method for measuring the element ratio of polyvalent metal elements in hydrotalcite particles, fatty acid metal salt particles, and toner particles> The element ratios of polyvalent metal elements in hydrotalcite particles, fatty acid metal salt particles, and toner particles are measured by EDS mapping of the toner using a scanning transmission electron microscope (STEM). EDS mapping measurements obtain spectral data for each pixel in the analysis area. Using a silicon drift detector with a large detection element area allows for highly sensitive EDS mapping measurements. By performing statistical analysis on the spectral data for each pixel obtained by EDS mapping measurement, it is possible to obtain a principal component mapping that extracts pixels with similar spectra, making it possible to map specific components.

[0105] The sample for observation is prepared according to the following procedure. 0.5 g of toner is weighed out and placed in a cylindrical mold with a diameter of 8 mm using a Newton press, which is left to stand for 2 minutes under a load of 40 kN to prepare a cylindrical toner pellet with a diameter of 8 mm and a thickness of approximately 1 mm. A 200 nm thick slice is prepared from the toner pellet using an ultramicrotome (Leica, FC7).

[0106] The STEM-EDS analysis is carried out using the following equipment and conditions. Scanning transmission electron microscope: JEOL JEM-2800 EDS detector: JEOL JED-2300T dry SD100GV detector (detector area: 100 mm 2 ) EDS analyzer: NORAN manufactured by Thermo Fisher Scientific System 7 [Conditions for STEM-EDS] STEM accelerating voltage: 200kV ·Magnification: 20,000x Probe size 1nm

[0107] STEM image size: 1024 x 1024 pixels (EDS elemental mapping images are acquired at the same position.) EDS mapping size: 256 x 256 pixels, Dwell time: 30 μs, Integration count: 100 frames The ratio of polyvalent metal elements in toner particles, and the ratio of each element in fatty acid metal salt particles and hydrotalcite particles are calculated based on multivariate analysis as follows.

[0108] The EDS mapping was obtained using the STEM-EDS analyzer. The collected spectral mapping data was then subjected to multivariate analysis using the COMPASS (PCA) mode in the measurement command of the NORAN System 7, and principal component map images were extracted. In this case, the setting values ​​were as follows: Kernel size: 3×3 Quantitative map setting: High (slow) Filter Fit Type: High Precision (Slow) At the same time, this operation calculates the area ratio of each extracted principal component to the EDS measurement field of view.Quantitative analysis is then performed on the EDS spectrum of each principal component mapping obtained using the Cliff-Lorimer method.

[0109] The toner particle portion, hydrotalcite particles, and fatty acid metal salt particles are distinguished based on the above-mentioned quantitative analysis results of the obtained STEM-EDS main component mapping. The particles can be identified as hydrotalcite particles based on the particle size, shape, content of polyvalent metals such as aluminum and magnesium, and their quantitative ratio. Similarly, the particles can be identified as fatty acid metal salt particles based on the particle size, shape, content of metals contained in the fatty acid metal salt particles, and their quantitative ratio.

[0110] (Calculation method of area ratios H1 and S1 of hydrotalcite particles and fatty acid metal salt particles to toner particles, and S1 / H1) Based on the mapping data obtained by the STEM-EDS mapping analysis of the toner obtained by the above method, the area ratio of each extracted main component to the toner particles can be calculated. 2) as the numerator, and calculate the sum of the area of ​​the hydrotalcite particles and the area of ​​the toner particles (nm 2 )" is used as the denominator, the value is calculated as the area ratio H1 of the hydrotalcite particles to the toner particles. Similarly, the area of ​​the fatty acid metal salt particle (nm 2 ) as a molecule, and Product(nm 2 ) and the area of ​​the toner particle (nm 2 ) is used as the denominator, the value is calculated as the area ratio S1 of the fatty acid metal salt particles to the toner particles. The mapping data is acquired from multiple fields of view, and the area ratio H1 (%) of the hydrotalcite particles to the toner particles and the area ratio S1 (%) of the fatty acid metal salt particles to the toner particles in the EDS measurement fields are calculated. The arithmetic mean of the respective values ​​for 30 fields of view is taken as the area ratios H1 and S1. Then, S1 / H1 is calculated from the obtained H1 and S1. Here, the fatty acid metal salt particles are identified in the mapping data by determining whether or not the structure of the isolated fatty acid metal salt particles, the type of metal atoms contained in the fatty acid metal salt particles, and the atomic ratio of carbon atoms to metal atoms contained in the fatty acid metal salt particles match in the fatty acid metal salt particle identification section.

[0111] (Method for analyzing fluorine and aluminum in hydrotalcite particles) Based on the mapping data obtained by the STEM-EDS mapping analysis using the method described above, the fluorine and aluminum in the hydrotalcite particles are analyzed. Specifically, EDS line analysis is performed in the normal direction to the outer periphery of the hydrotalcite particles, and the fluorine and aluminum present inside the particles are analyzed. A schematic diagram of line analysis is shown in Figure 1(a). For toner particle 1 and hydrotalcite particle 3 adjacent to toner particle 2, line analysis is performed in the normal direction to the periphery of hydrotalcite particle 3, i.e., in the direction of 5. Note that 4 indicates the boundary of the toner particle. The area in the acquired STEM image where hydrotalcite particles exist is selected using the rectangular selection tool, and line analysis is performed under the following conditions. Line analysis conditions STEM magnification: 800,000x Line length: 200nm Line width: 30nm Number of line divisions: 100 points (intensity measurement every 2 nm) When the elemental peak intensity of fluorine or aluminum in the EDS spectrum of the hydrotalcite particles is 1.5 times or more the background intensity, and when the elemental peak intensity of fluorine or aluminum at both ends of the hydrotalcite particles in line analysis (points a and b in Figure 1(a)) does not exceed 3.0 times the peak intensity at point c, the element is determined to be contained inside the hydrotalcite particles. Point c is the midpoint of line segment ab (i.e., the midpoint of the above-mentioned both ends). Examples of X-ray intensities of fluorine and aluminum obtained by line analysis are shown in Figures 1(b) and 1(c). When hydrotalcite particles contain fluorine and aluminum inside, the graph of X-ray intensity normalized by peak intensity shows a shape like that shown in Figure 1(b). When hydrotalcite particles contain fluorine derived from a surface treatment agent, the graph of X-ray intensity normalized by peak intensity has peaks near points a and b, both ends of the fluorine graph, as shown in Figure 1(c). By checking the X-ray intensities derived from fluorine and aluminum in line analysis, it can be confirmed that the hydrotalcite particles contain fluorine and aluminum inside.

[0112] (Method for calculating the ratio of the atomic concentration of fluorine to aluminum in hydrotalcite particles (element ratio) F / Al) The atomic concentration ratio value (element ratio) F / Al of fluorine to aluminum in the hydrotalcite particles obtained from the main component mapping derived from the hydrotalcite particles by the STEM-EDS mapping analysis described above is obtained from multiple fields of view, and the arithmetic average of the values ​​for 100 or more relevant particles is taken to determine the atomic concentration ratio value (element ratio) F / Al of fluorine to aluminum in the hydrotalcite particles.

[0113] (Method for calculating the ratio of the atomic concentration of magnesium to aluminum in hydrotalcite particles (element ratio) Mg / Al) The same method as that for calculating the atomic concentration ratio (element ratio) F / Al of fluorine to aluminum in the hydrotalcite particles described above is applied to magnesium and aluminum to calculate the atomic concentration ratio (element ratio) Mg / Al of magnesium to aluminum in the hydrotalcite particles.

[0114] <Calculation methods for fluorine atom number concentration in hydrotalcite particles, metal atom number concentration in fatty acid metal salt particles, and S2 / H2> Based on the mapping data obtained by the STEM-EDS mapping analysis using the method described above, the atomic concentration of fluorine in the hydrotalcite particles and the atomic concentration of metal atoms in the fatty acid metal salt particles are calculated. In the main component map images of the hydrotalcite particles and the fatty acid metal salt particles extracted using the method described above, the atomic concentration of fluorine (element amount) in the hydrotalcite particles and the atomic concentration of metal atoms (element amount) in the fatty acid metal salt particles are quantified. H2 and S2 are calculated by multiplying the atomic concentration of fluorine in the hydrotalcite particles by H1 and 100, and the atomic concentration of metal atoms in the fatty acid metal salt particles by S1 and 100, respectively. The mapping data is obtained from a plurality of fields of view, and the arithmetic averages are calculated for 100 or more hydrotalcite particles and fatty acid metal salt particles, and these are designated as H2 and S2, respectively. Then, S2 / H2 is calculated from the obtained H2 and S2.

[0115] <Method for measuring the number average particle size H3 of primary particles of hydrotalcite particles and the number average particle size S3 of primary particles of fatty acid metal salt particles> The number-average particle size H3 of the primary particles of the hydrotalcite particles and the number-average particle size S3 of the primary particles of the fatty acid metal salt particles are measured using a scanning electron microscope "S-4800" (trade name; manufactured by Hitachi, Ltd.) in combination with elemental analysis by energy dispersive X-ray analysis (EDS). A toner containing externally added hydrotalcite particles and fatty acid metal salt particles is observed, and the hydrotalcite particles and fatty acid metal salt particles are photographed at a magnification of up to 200,000 times. From the photographed image, hydrotalcite particles and fatty acid metal salt particles are selected, and the major axis of the primary particles of 100 hydrotalcite particles and fatty acid metal salt particles is measured at random to determine the number-average particle size of the hydrotalcite particles and fatty acid metal salt particles. The observation magnification is adjusted appropriately depending on the size of the external additive.

[0116] (Method for calculating the content of polyvalent metal elements in toner particles) The elemental amounts (atomic number concentrations) of polyvalent metal elements and carbon in the toner particles can be obtained from the principal component mapping derived from the toner particles by the above-mentioned STEM-EDS mapping analysis. The elemental amount (atomic number concentration) of polyvalent metal elements such as aluminum, when the elemental amount (atomic number concentration) of carbon is set to 100, is defined as the "content of polyvalent metal elements in the toner particles." The mapping data is acquired from multiple fields of view, and the arithmetic average is taken for 100 or more toner particles to calculate the "content of polyvalent metal elements in the toner particles."

[0117] <Method for measuring the glass transition temperature (Tg) of a resin> The glass transition temperature of the resin is measured in accordance with ASTM D3418-97. Specifically, 10 mg of the dried resin was weighed out and placed in an aluminum pan. An empty aluminum pan was used as a reference. The glass transition temperature of the weighed resin was measured using a differential scanning calorimeter (manufactured by SII NanoTechnology, Inc., product name: DSC6220) in accordance with ASTM D 3418-97 at a heating rate of 10°C / min over a temperature range of 0°C to 150°C.

[0118] <Identification of wax in toner> (1) Method for separating wax from toner First, the melting point of the wax in the toner was measured using a thermal analyzer (DSC Q2000, manufactured by TA Instruments Japan Co., Ltd.). 3.0 mg of the toner sample was placed in a sample container in an aluminum pan (KIT No. 0219-0041), which was then placed on a holder unit and placed in an electric furnace. Under a nitrogen atmosphere, the sample was heated from 30°C to 200°C at a rate of 10°C / min. The DSC curve was measured using a differential scanning calorimeter (DSC), and the melting point of the wax in the toner sample was calculated. Next, the toner is dispersed in ethanol, a poor solvent for the toner, and the temperature is raised to a temperature above the melting point of the wax. If necessary, pressure may be applied during this process. By this operation, the wax has exceeded its melting point and is melted and extracted into the ethanol. The wax can be separated from the toner by heating, and if pressure is applied, by performing solid-liquid separation while still under pressure. The extracted liquid is then dried and solidified to obtain the wax.

[0119] (2) Identification of wax by pyrolysis GCMS The specific conditions for identifying wax by pyrolysis GCMS are shown below. Mass spectrometer: ThermoFisherScinetific ISQ GC equipment: ThermoFisher Scientific FocusGC Ion source temperature: 250℃ Ionization method: EI Mass range: 50-1000 m / z Column: HP-5MS [30 m] Pyrolysis equipment: Japan Analytical Industry Co., Ltd. JPS-700

[0120] A small amount of the wax separated by extraction and 1 μL of tetramethylammonium hydroxide (TMAH) are added to a pyrofoil at 590°C. The resulting sample is subjected to pyrolysis GCMS measurement under the above conditions, and peaks derived from the wax are obtained. If the wax is an ester compound, peaks are obtained for the alcohol and carboxylic acid components. Due to the action of TMAH, a methylating agent, the alcohol and carboxylic acid components are detected as methylated products. By analyzing the peaks obtained and identifying the structure of the ester compound, the molecular weight can also be obtained.

[0121] <Binder resin composition analysis> -Method for separating binder resin from toner Dissolve 100 mg of toner in 3 ml of chloroform. Next, remove the insoluble matter by suction filtration using a syringe equipped with a sample processing filter (pore size 0.2 μm to 0.5 μm, such as a Myshoridisk H-25-2 (Tosoh Corporation)). The soluble matter is introduced into a preparative HPLC (apparatus: Japan Analytical Industry Co., Ltd. LC-9130 NEXT preparative column [60 cm], exclusion limits: 20,000 and 70,000, two columns connected), and chloroform eluent is pumped. Once a peak is confirmed in the resulting chromatographic display, fractionate the fraction with a retention time of 2,000 or higher molecular weight using a monodisperse polystyrene standard sample. The resulting fraction solution is dried and solidified to obtain the binder resin.

[0122] - Identification of binder resin components and measurement of mass ratios using nuclear magnetic resonance spectroscopy (NMR) 1 mL of deuterated chloroform is added to 20 mg of toner, and the NMR spectrum of the protons of the dissolved binder resin is measured. From the obtained NMR spectrum, the molar ratio and mass ratio of each monomer can be calculated, and the content of the constituent monomer units of the binder resin, such as styrene-acrylic resin, can be determined. For example, in the case of a styrene-acrylic copolymer, the composition ratio and mass ratio can be calculated based on the peak at around 6.5 ppm derived from the styrene monomer and the peak at around 3.5-4.0 ppm derived from the acrylic monomer. In addition, the composition ratio and mass ratio of polyester resin and styrene-acrylic resin can be calculated based on the peak at around 6.5 ppm derived from the styrene monomer and the peak at around 3.5-4.0 ppm derived from the acrylic monomer. In the case of a copolymer of styrene-acrylic resin, the molar ratio and mass ratio are calculated based on the peaks derived from each monomer constituting the polyester resin and the peak derived from the styrene-acrylic copolymer. NMR device: JEOL RESONANCE ECX500 Observation nucleus: Proton Measurement mode: Single pulse Base peak: TMS

[0123] Identification of the components of shell resin B using time-of-flight secondary ion mass spectrometry (TOF-SIMS) Time-of-flight secondary ion mass spectrometry (TOF-SIMS) can obtain information from the surface of toner particles down to a few nanometers, making it possible to identify the constituent materials near the outermost surface of the toner particles. To identify the resin present on the surface of toner particles using TOF-SIMS, a TRIFT-IV manufactured by ULVAC-PHI, Inc. is used. The analysis conditions are as follows: Sample preparation: Adhesion of toner to an indium sheet Sample preparation: None Primary ions: Au ions Accelerating voltage: 30 kV Charge neutralization mode: On Measurement mode: Negative Raster: 100 μm

[0124] From each peak, the composition of the resin present on the surface of the toner particle is identified and its abundance ratio is calculated. For example, S211 is a peak derived from bisphenol A. Also, for example, S85 is a peak derived from butyl acrylate. When calculating the peak intensity (S85) derived from vinyl resin: According to the standard software (Win Cadense) of ULVAC-PHI, the total count number of mass numbers 84.5 to 85.5 is taken as the peak intensity (S85). When calculating the peak intensity (S211) due to amorphous polyester, the total count number of mass numbers 210.5 to 211.5 is taken as the peak intensity (S211) according to ULVAC-PHI's standard software (Win Cadense).

[0125] <Method for measuring the average circularity of toner particles> The average circularity of the toner or toner particles is measured using a flow particle image analyzer, "FPIA-3000" (manufactured by Sysmex Corporation), under the measurement and analysis conditions during the calibration work. To 20 mL of ion-exchanged water, an appropriate amount of surfactant, alkylbenzene sulfonate, was added as a dispersant, and then 0.02 g of the measurement sample was added. The mixture was dispersed for 2 minutes using a tabletop ultrasonic cleaner disperser (product name: VS-150, manufactured by Vervoclear Co., Ltd.) with an oscillation frequency of 50 kHz and an electrical output of 150 watts to obtain a dispersion for measurement. The dispersion was then cooled appropriately so that its temperature was between 10°C and 40°C. For the measurement, the flow-type particle image analyzer equipped with a standard objective lens (10x) was used, and the particle sheath "PSE-900A" (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion prepared according to the above procedure was introduced into the flow-type particle image analyzer, and 3,000 toner particles (particles) were measured in HPF measurement mode and total count mode. The binarization threshold for particle analysis was set to 85%, and the analyzed particle diameter was limited to a circle-equivalent diameter of 1.98 μm to 19.92 μm, and the average circularity of the toner particles was determined. Before starting the measurement, automatic focus adjustment is performed using standard latex particles (for example, 5100A (trade name) manufactured by Duke Scientific diluted with ion-exchanged water). After that, it is preferable to perform focus adjustment every two hours from the start of the measurement.

[0126] <Measurement of weight average molecular weight Mw, number average molecular weight Mn, and peak molecular weight> The molecular weight distribution (weight average molecular weight Mw, number average molecular weight Mn, peak molecular weight) of a resin or the like is measured by gel permeation chromatography (GPC) as follows. First, the sample is dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. 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 THF is 0.8 mass%. This sample solution is used for measurements under the following conditions. Apparatus: HLC8120GPC (detector: RI) (Tosoh Corporation) Column: Shodex KF-801, 802, 803, 804, 805, 806, 807 (7 columns, manufactured by Showa Denko Co., Ltd.) Eluent: tetrahydrofuran (THF) ·Flow rate: 1.0ml / min Oven temperature: 40.0℃ Sample injection volume: 0.10 ml To calculate the molecular weight of a sample, a molecular weight calibration curve prepared using standard polystyrene resins (for example, 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.

[0127] <Method for measuring melting point> The melting point of the crystalline material (crystalline resin or wax) is measured using a differential scanning calorimeter (DSC) Q2000 (manufactured by TA Instruments) under the following conditions. Heating rate: 10℃ / min Measurement start temperature: 20℃ Measurement end temperature: 180℃ 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. Specifically, approximately 5 mg of sample is weighed out and placed in an aluminum pan, and a single measurement is performed. An empty aluminum pan is used as a reference. The peak temperature of the maximum endothermic peak at this time is taken as the melting point.

[0128] <Method for measuring particle shape such as volume-based median diameter of toner> The particle shape, such as the volumetric median diameter of the toner, is calculated as follows. 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 narrow-pore electrical resistance method and equipped 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 using an effective number of 25,000 measurement channels. The aqueous electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of approximately 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter). Before carrying out the measurement and analysis, the dedicated software is set up as follows. On the "Change Standard Measurement Method (SOMME)" screen of the dedicated software, set the total count number in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particle 10.0 μm" (manufactured by 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, and the electrolyte to ISOTON II, and then click " Check "Flush aperture tube after measurement." On the "Pulse to particle size conversion setting" screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bins, and the particle size range is set to 2 μm to 60 μm. The specific measurement method is as follows.

[0129] (1) Pour approximately 200 mL of the electrolyte solution into a 250 mL round-bottom glass beaker made specifically for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture tube flush" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube. (2) Approximately 30 mL of the above-mentioned aqueous electrolyte solution is placed in a 100 mL flat-bottom glass beaker, and approximately 0.3 mL of a 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, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) as a dispersant with ion-exchanged water by approximately three times its mass is added. (3) Prepare an ultrasonic disperser "Ultrasonic Dispersion System Tetra150" (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 approximately 3.3 L of ion-exchanged water in the ultrasonic disperser's water tank and add approximately 2 mL of Contaminon N to this water tank. (4) Set the beaker (2) in 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 liquid surface of the electrolytic solution in the beaker is maximized. (5) While the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, approximately 10 mg of toner is added little by little to the electrolyte solution and dispersed. The ultrasonic dispersion process is then continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to 10°C to 40°C. (6) Using a pipette, the electrolytic solution (5) containing the dispersed toner is dropped into the round-bottom beaker (1) placed in the sample stand, and the measurement concentration is adjusted to approximately 5%. Then, measurements are continued until the number of particles measured reaches 50,000. (7) The measurement data is analyzed using the dedicated software provided with the device, and the volume-based median diameter is calculated.

[0130] <Method for identifying fatty acid metal salts> (1) Method for isolating fatty acid metal salt particles from toner 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. In a 50 mL centrifuge tube, add 31 g of the above 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, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.). Add 1.0 g of toner and break up any clumps of toner with a spatula or similar. The centrifuge tube was shaken at 300 strokes per minute (spm) for 20 minutes in a shaker (AS-1N, sold by AS ONE Corporation). After shaking, the solution was transferred to a glass tube (50 mL) for a swing-out rotor and centrifuged at 3500 rpm for 30 minutes in a centrifuge (H-9R, manufactured by Kokusan Corporation). It was visually confirmed that the toner particles and the aqueous solution had been sufficiently separated by this operation, and the toner particles separated into the uppermost layer were collected with a spatula or the like to separate the toner particles from the dispersion liquid. Thereafter, the dispersion liquid from which the toner particles had been collected was centrifuged again, and the dispersion liquid containing the fatty acid metal salt separated in the upper layer was collected again. The above procedure was repeated to collect the dispersion containing the fatty acid metal salt, and then centrifuged again to obtain a concentrated solution with an increased concentration of the fatty acid metal salt. The concentrated solution was air-dried for one day, and then dried in a dryer at 40°C for 8 hours or more to obtain a measurement sample. This procedure was repeated multiple times to obtain the required amount of isolated fatty acid metal salt particles.

[0131] (2) Identification of the central metal by X-ray fluorescence The isolated fatty acid metal salt particles were subjected to X-ray fluorescence measurement and composition analysis to identify the metal elements in the fatty acid metal salt particles.

[0132] (3) Identification of fatty acids in fatty acid metal salts by pyrolysis GCMS The specific conditions for identifying fatty acid metal salts by pyrolysis GCMS are shown below. Mass spectrometer: ThermoFisherScinetific ISQ GC equipment: ThermoFisher Scientific FocusGC Ion source temperature: 250℃ Ionization method: EI Mass range: 50-1000 m / z Column: HP-5MS [30 m] Pyrolysis equipment: Japan Analytical Industry Co., Ltd. JPS-700

[0133] The fatty acid metal salt separated by the isolation procedure and 1 μL of tetramethylammonium hydroxide (TMAH) were added to a pyrofoil at 590°C. The resulting sample was subjected to pyrolysis GCMS measurement under the above conditions, and peaks derived from the fatty acid metal salt were obtained. Due to the action of TMAH, a methylating agent, the fatty acid components were detected as methylated products. The resulting peaks were analyzed, and the fatty acid structure of the fatty acid metal salt was identified. [Example]

[0134] 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 mass unless otherwise specified.

[0135] An example of toner production will be described below. <Toner 1 manufacturing example> <Preparation example of resin particle dispersion 1> 72.0 parts styrene 26.7 parts butyl acrylate 1.3 parts acrylic acid 3.2 parts n-lauryl mercaptan The above materials were placed in a container and mixed by stirring. An aqueous solution of 1.5 parts of Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 150.0 parts of ion-exchanged water was added to this solution and dispersed. An aqueous solution of 0.3 parts potassium persulfate and 10.0 parts ion-exchanged water was added with slow stirring for an additional 10 minutes. After nitrogen substitution, emulsion polymerization was carried out at 70°C for 6 hours. After polymerization was completed, the reaction solution was cooled to room temperature, and ion-exchanged water was added to obtain resin particle dispersion 1 with a solids concentration of 12.5% ​​by mass and a glass transition temperature of 48°C. The particle size distribution of the resin particles contained in this resin particle dispersion 1 was measured using a particle size analyzer (HORIBA, Ltd., LA-920), and the number-average particle size of the resin particles contained was 0.2 μm. Furthermore, no coarse particles exceeding 1 μm were observed.

[0136] <Preparation example of resin particle dispersion 2> 77.0 parts styrene 21.7 parts butyl acrylate 1.3 parts acrylic acid 3.2 parts n-lauryl mercaptan The above materials were placed in a container and mixed by stirring. An aqueous solution of 1.5 parts of Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 150.0 parts of ion-exchanged water was added to this solution and dispersed. While slowly stirring for another 10 minutes, an aqueous solution of 0.3 parts potassium persulfate and 10.0 parts ion-exchanged water was added. After nitrogen substitution, emulsion polymerization was carried out at 70°C for 6 hours. After polymerization was completed, the reaction solution was cooled to room temperature, and ion-exchanged water was added to obtain resin particle dispersion 2 with a solids concentration of 12.5% ​​by mass and a glass transition temperature of 60°C. The particle size distribution of the resin particles contained in this resin particle dispersion 2 was measured using a particle size analyzer (HORIBA, Ltd., LA-920), and the number-average particle size of the resin particles contained was 0.2 μm. Furthermore, no coarse particles exceeding 1 μm were observed.

[0137] <Preparation example of release agent dispersion 1> 100.0 parts of pentaerythritol tetrastearate (melting point: 77°C) and 15.0 parts of NEOGEN RK were mixed with 385.0 parts of ion-exchanged water, and the mixture was dispersed for about 1 hour using a wet jet mill JN100 (manufactured by Joko Corporation) to obtain release agent dispersion 1. The wax concentration in release agent dispersion 1 was 20.0% by mass. The particle size distribution of the release agent particles contained in this release agent dispersion 1 was measured using a particle size measuring device (LA-920, manufactured by Horiba, Ltd.), and the number average particle size of the release agent particles contained was 0.35 μm. Furthermore, no coarse particles exceeding 1 μm were observed.

[0138] <Preparation example of release agent dispersion 2> 100.0 parts of hydrocarbon wax HNP-9 (manufactured by Nippon Seiro Co., Ltd., melting point: 75.5°C), 15 parts of NEOGEN RK were mixed with 385.0 parts of ion-exchanged water, and the mixture was dispersed for about 1 hour using a wet jet mill JN100 (manufactured by Joko Co., Ltd.) to obtain release agent dispersion 2. The wax concentration in release agent dispersion 2 was 20.0% by mass. The particle size distribution of the release agent particles contained in this release agent dispersion 2 was measured using a particle size measuring device (LA-920, manufactured by Horiba, Ltd.), and the number average particle size of the release agent particles contained was 0.35 μm. Furthermore, no coarse particles exceeding 1 μm were observed.

[0139] <Preparation example of colorant dispersion 1> As a colorant, 100.0 parts of carbon black "Nipex 35 (manufactured by Orion Engineered Carbons)" and 15 parts of Neogen RK were mixed with 885.0 parts of ion-exchanged water, and dispersed for about 1 hour using a wet jet mill JN100 to obtain a colorant dispersion. The particle size distribution of the colorant particles contained in this colorant particle dispersion 1 was measured using a particle size analyzer (LA-920 manufactured by Horiba, Ltd.) and the number average particle size of the colorant particles contained was 0.2 μm. Furthermore, no coarse particles exceeding 1 μm were observed.

[0140] <Preparation of Toner Particles 1> ·Resin particle dispersion 1:265.0 parts Release agent dispersion 1:10.0 parts Release agent dispersion 2: 8.0 parts Colorant dispersion: 16.0 parts In the core formation process, the above materials were placed in a round stainless steel flask and mixed. Then, a homogenizer (IKA Ultra Turrax T50) was used to mix the materials at 5000 rpm. The temperature inside the container was adjusted to 30°C while stirring, and a 1 mol / L aqueous solution of sodium hydroxide was added to adjust the pH to 8.0.

[0141] As a flocculant, an aqueous solution of 0.25 parts of aluminum chloride dissolved in 10.0 parts of ion-exchanged water was added at 30°C over 10 minutes with stirring. After leaving it for 3 minutes, the temperature was raised to 60°C to generate aggregated particles (core formation). The volume-based median diameter of the formed aggregated particles was measured using a Coulter Counter Multisizer 3 (registered trademark, The particle size was conveniently confirmed using a Beckman Coulter (Beckman Coulter, Inc.). When the volume-based median diameter reached 7.0 μm, 2:15.0 parts of resin particle dispersion was added and the mixture was stirred for another hour to form a shell.

[0142] Thereafter, a 1 mol / L aqueous solution of sodium hydroxide was added to adjust the pH to 9.0, and the temperature was raised to 95° C. to spheronize the aggregated particles. When the average circularity reached 0.980, the temperature was lowered and the mixture was cooled to room temperature, thereby obtaining toner particle dispersion 1.

[0143] Hydrochloric acid was added to the obtained toner particle dispersion 1 to adjust the pH to 1.5 or less, and the mixture was stirred and left for 1 hour, after which solid-liquid separation was performed using a pressure filter to obtain a toner cake. This was reslurried with ion-exchanged water to make a dispersion again, and then solid-liquid separation was performed using the above-mentioned filter. The reslurrying and solid-liquid separation were repeated until the electrical conductivity of the filtrate was 5.0 μS / cm or less, and finally solid-liquid separation was performed to obtain a toner cake. The obtained toner cake was dried and further classified using a classifier so that the volume-based median diameter was 7.0 μm, obtaining toner particles 1.

[0144] The formulation and physical properties of the obtained toner particles are shown in Table 1. [Table 1] In the table, "Parts of shell" refers to the number of parts by mass of the resin for the shell relative to 100 parts by mass of the resin for the core particles.

[0145] <Production Examples of Toner Particles 2 to 7> Toner particles 2 to 7 were obtained in the same manner as in the production example of toner particles 1, except that the type and amount of aggregating agent were changed as shown in Table 1. The physical properties of the obtained toner particles 2 to 7 are shown in Table 1.

[0146] <Preparation of Hydrotalcite Particles 1> A mixed aqueous solution of 1.03 mol / L magnesium chloride and 0.239 mol / L aluminum sulfate (liquid A), a 0.753 mol / L sodium carbonate aqueous solution (liquid B), and a 3.39 mol / L sodium hydroxide aqueous solution (liquid C) were prepared. Next, liquids A, B, and C were poured into a reaction vessel using a metering pump at a flow rate such that the volume ratio of liquid A to liquid B was 4.5:1. The pH value of the reaction solution was maintained in the range of 9.3 to 9.6 using liquid C, and the reaction temperature was 40°C to produce a precipitate. After filtration and washing, the precipitate was re-emulsified in ion-exchanged water to obtain a raw material hydrotalcite slurry. The hydrotalcite concentration in the obtained hydrotalcite slurry was 5.6% by mass. The obtained hydrotalcite slurry was vacuum dried overnight at 40°C. NaF was dissolved in ion-exchanged water to a concentration of 100 mg / L, and a solution was prepared by adjusting the pH to 7.0 using 1 mol / L HCl or 1 mol / L NaOH, to which the dried hydrotalcite was added to a concentration of 0.1% (w / v%). The mixture was stirred at a constant speed using a magnetic stirrer for 48 hours to prevent settling. The mixture was then filtered through a membrane filter with a pore size of 0.5 μm and washed with ion-exchanged water. The obtained hydrotalcite was then dried at 40°C. The resulting hydrotalcite particles were dried in a vacuum overnight and then crushed. The composition and physical properties of the resulting hydrotalcite particles 1 are shown in Table 2.

[0147] <Preparation of Hydrotalcite Particles 2 to 11> Except for appropriately adjusting the concentrations of Solution A, Solution B, and the NaF aqueous solution, hydrotalcite particles 2 to 11 were obtained in the same manner as in the production example of Hydrotalcite Particle 1. The compositions and physical properties of the obtained Hydrotalcite Particles 2 to 11 are shown in Table 2.

[0148] <Preparation of Hydrotalcite Particles 12> Hydrotalcite particles 12 were obtained in the same manner as in the production example of hydrotalcite particles 1, except that ion-exchanged water was used instead of the NaF aqueous solution in the production example of hydrotalcite particles 1. The composition and physical properties of the obtained hydrotalcite particles 12 are shown in Table 2.

[0149] <Preparation of Hydrotalcite Particles 13> Hydrotalcite particles 13 were obtained in the same manner as in the production example of hydrotalcite particles 12, except that the obtained slurry containing the hydrotalcite compound was surface-treated by adding 5 parts by mass of fluorosilicone oil to 95 parts by mass of solids before being vacuum-dried overnight at 40° C. The composition and physical properties of the obtained hydrotalcite particles 13 are shown in Table 2. [Table 2]

[0150] <Preparation of fatty acid metal salt particles 1> A receiver equipped with a stirrer was prepared, and the stirrer was rotated at 300 rpm. 500 parts of a 0.5% by mass aqueous solution of sodium stearate was added to the receiver, and the liquid temperature was adjusted to 85°C. Next, 525 parts of a 0.2% by mass aqueous solution of zinc sulfate was added dropwise to the receiver over 15 minutes. After the entire amount was added, the mixture was aged for 10 minutes at the reaction temperature to terminate the reaction. Next, the fatty acid metal salt slurry thus obtained was filtered and washed. The washed fatty acid metal salt cake obtained was roughly crushed and then dried at 100°C using a continuous flash air dryer. Thereafter, it was crushed in a nano grinding mill [NJ-300] (manufactured by Sunrex Co., Ltd.) with an air volume of 6.0 m 3 / min, processing speed 80 kg / h, then reslurried and passed through a wet centrifugal classifier. Fine and coarse particles were removed using a continuous flash air dryer. The particles were then dried at 80°C using a continuous flash air dryer to obtain fatty acid metal salt particles 1. The physical properties of fatty acid metal salt particles 1 are shown in Table 3.

[0151] <Preparation of fatty acid metal salt particles 2 to 7> Fatty acid metal salt particles 2 to 7 were obtained in the same manner as fatty acid metal salt particles 1, except that the materials were changed and the number average particle size was adjusted as shown in Table 3. The physical properties of fatty acid metal salt particles 2 to 7 are shown in Table 3. [Table 3]

[0152] <Toner 1 manufacturing example> Toner particles 1 (98.4 parts) obtained above, hydrotalcite particles 1 (0.2 parts), fatty acid metal salt particles 1 (0.1 parts), and silica particles 1 (RX200: primary average particle size 12 nm, HMDS treatment, manufactured by Nippon Aerosil Co., Ltd.) (1.5 parts) were externally added and mixed using an FM10C (manufactured by Nippon Coke and Engineering Co., Ltd.). The external addition conditions were as follows: the lower blade was set to A0 blade, the gap to the deflector wall was set to 20 mm, the amount of toner particles charged was 2.0 kg, and the rotation speed was set to 66.6 s -1 The external addition time was 10 minutes, and the cooling water temperature was 20°C and the flow rate was 10 L / min. Thereafter, the mixture was sieved through a mesh having an opening of 200 μm to obtain Toner 1. The physical properties of Toner 1 obtained are shown in Tables 4 and 5. [Table 4] In Table 4, H particles represent hydrotalcite particles, S particles represent fatty acid metal salt particles, H-1 to H-13 represent hydrotalcite particles 1 to 13, S-1 to S-7 represent fatty acid metal salt particles 1 to 7, H3 represents the number average particle size of the primary particles of the hydrotalcite particles, and S3 represents the number average particle size of the primary particles of the fatty acid metal salt particles. [Table 5] In Table 5, * indicates whether fluorine atoms are contained inside the hydrotalcite particles, and "yes" and "no" indicate that fluorine atoms are contained inside the hydrotalcite particles, respectively. H1 indicates the area ratio of the hydrotalcite particles to the toner particles, H2 indicates the product of the F atom % and H1 times 100, H3 indicates the number-average particle size of the primary particles of the hydrotalcite particles, S1 indicates the area ratio of the fatty acid metal salt particles to the toner particles, S2 indicates the product of the metal atom % and S2 times 100, and S3 indicates the number-average particle size of the primary particles of the fatty acid metal salt particles, and the content indicates the content of the polyvalent metal element (element ratio to carbon) in the toner particles.

[0153] <Production examples of toners 2 to 49> The same procedure as in the production example of Toner 1 was carried out except that the toner particles, hydrotalcite particles, fatty acid metal salt particles, and the amounts of these particles added were changed as shown in Table 4. Thus, toners 2 to 49 were obtained. The physical properties of the toners 2 to 49 obtained are shown in Tables 4 and 5.

[0154] <Image evaluation> Image evaluation was performed using a commercially available color laser printer (HP LaserJet Enterprise Color M611dn, manufactured by HP) with some modifications. Specifically, the printer was modified so that it could operate with only one color process cartridge installed, and the transfer current could be changed to the desired value. The toner was removed from the cyan cartridge and replaced with 325 g of the toner to be evaluated. The cyan cartridge filled with the toner to be evaluated was installed in the main body, and the evaluation was performed with no cartridges other than the cyan cartridge installed. The evaluation was performed using the following evaluations 1 to 6.

[0155] <Evaluation 1: Cleaning performance evaluation in low temperature and low humidity environments> The main body and cartridge filled with toner were left in a low-temperature, low-humidity environment (temperature 15°C, humidity 5% RH) for one day, and then, under the above environment, the transfer current was increased by 20% from the normal setting, and 40,000 sheets of horizontal line images with a print rate of 1% were printed in intermittent mode. After printing, the transfer current was returned to the normal setting, and three halftone images with a print rate of 23% were printed (Halftone Image 1). The evaluation paper was Copykid copy paper (manufactured by UPM, A4 size 210 × 297 mm, basis weight 70 g / m 2 ) was used.

[0156] Copykid copy paper generates a lot of paper dust, and when used in a low-temperature, low-humidity environment or when used under conditions of high transfer current, the paper dust is particularly likely to become negative and transfer to the photoreceptor. Therefore, this evaluation using such paper is an evaluation under strict conditions regarding the ability to clean paper dust. In this evaluation, if the toner has poor cleaning properties, paper dust, external additives, and toner that have slipped through the cleaning process will contaminate the charging roller, reducing the charging ability of the contaminated areas, resulting in the appearance of black vertical streaks when a halftone image is printed. Therefore, the number of vertical streaks that occurred on three halftone images obtained after printing 40,000 sheets was counted, and the cleaning ability in a low-temperature, low-humidity environment was judged according to the following criteria: C or better was judged as good. [Evaluation criteria] A. The width of the streaks is less than 0.5 mm, and the number of streaks is three or less. B. The width of the streaks is less than 0.5 mm, and the number of streaks is between 4 and 6. C. The width of the streaks is less than 0.5 mm, and the number of streaks is between 7 and 9. D. There are 10 or more streaks with a width of less than 0.5 mm, or streaks of 0.5 mm or more have occurred.

[0157] <Evaluation 2: Fog evaluation after durability test in low temperature and low humidity environment> The main unit and cartridge filled with toner were left in a low-temperature, low-humidity environment (temperature 15°C, humidity 5% RH) for one day, and then, under the above environment, 40,000 sheets of horizontal line images with a print rate of 1% were printed in intermittent mode, and then three sheets of all-white images with part of the paper masked by a sticky note were printed. The paper used for evaluation was Copykid copy paper (UPM, A4 size, 210 × 297 mm, basis weight 70 g / m), which is prone to generating paper dust. 2 ) was used.

[0158] After removing the sticky notes, the reflectance (%) was measured at five points on each of the areas with and without sticky notes, and the average value was calculated. The difference between the average values ​​was then calculated and used as the fog after durability testing in a low-temperature, low-humidity environment. The reflectance was measured using a digital white light meter (TC-6D model, manufactured by Tokyo Denshoku Co., Ltd., using a green filter). The evaluation criteria are as follows, with the lower the value, the better the result. A grade of C or higher was considered good. [Evaluation criteria] A. Fog is less than 0.5% B. Fog is 0.5% or more but less than 1.0% C. Fog is 1.0% or more but less than 1.5% D. Fog is 1.5% or more

[0159] <Evaluation 3: Print rate stability after cleaning in a low-temperature, low-humidity environment> The main body and cartridge filled with toner were left in a low-temperature, low-humidity environment (temperature 15°C, humidity 5% RH) for one day, and then, under the above environment, 5,000 sheets were printed in intermittent mode with an image in which a horizontal line with a print rate of 1% was printed on the left half and a solid black image on the right half, and then three sheets of halftone images (print rate 23%) were printed. The evaluation paper was Copykid copy paper (UPM, A4 size, 210 x 297 mm, basis weight 70 g / m), which generates a lot of paper dust. 2 ) was used.

[0160] If there is a difference in cleaning ability depending on the printing rate of the image to be output, there will be a difference in the level of contamination of the charging roller, which will result in a difference in the amount of charge imparted to the photosensitive member, and in the above evaluation, a difference will appear in the half-tone density difference between the left and right sides. The printing rate stability of cleaning was evaluated for the three obtained halftone images (print rate 23%) based on the difference in halftone density between the left side (the area where durability was evaluated with an image having a low printing rate) and the right side (the area where durability was evaluated with an image having a high printing rate). The halftone image density on the left side of each image was measured at 10 points and the average value was calculated (left side halftone density), and similarly the halftone image density on the right side of each image was measured at 10 points and the average value was calculated (right side halftone density). Thereafter, the smaller the difference in density between the left half-tone density and the right half-tone density, the better the cleaning print rate stability, and the evaluation criteria are as follows: C or higher was judged to be good. [Evaluation criteria] A. The halftone density difference is less than 0.04. B. The halftone density difference is 0.04 or more and less than 0.07. C. The halftone density difference is 0.07 or more and less than 0.10. D. The halftone density difference after durability is 0.10 or more.

[0161] <Evaluation 4: Halftone reproducibility in a low-temperature, low-humidity environment> The main body and cartridge filled with toner were left in a low-temperature, low-humidity environment (temperature 15°C, humidity 5%RH) for one day, and then 5,000 sheets of horizontal line images with a print rate of 4% were output in intermittent mode under the same environment, followed by a halftone image with a print rate of 23%. The halftone images were observed using a microscope, and the cross-sectional areas of the dots were binarized by image analysis to determine the average and standard deviation of the cross-sectional areas. The standard deviation was divided by the average and multiplied by 100 to obtain the CV%, and the halftone reproducibility was evaluated based on the CV% value according to the following criteria. The sharper the charge distribution of the toner, the better the halftone reproducibility. [Evaluation criteria] A: CV% is less than 10% B: CV% is 10% or more but less than 15% C: CV% is 15% or more but less than 20% D: CV% is 20% or more

[0162] <Evaluation 5: Cleaning performance evaluation in an extremely low temperature and low humidity environment> After leaving the main body and the cartridge filled with toner in an extremely low temperature and low humidity environment (temperature 0°C, humidity 5% RH) for one day, a horizontal line image with a print rate of 10% was printed in intermittent mode 5,000 times under the above environment. After printing, three halftone images with a print rate of 23% were printed (Halftone image 1). The evaluation paper was Copykid copy paper (manufactured by UPM, A4 size 210 × 297 mm, basis weight 70 g / m 2 ) was used.

[0163] Copykid copy paper generates a lot of paper dust, so this evaluation using such paper is an evaluation under strict conditions regarding the ability to clean paper dust. Furthermore, in an extremely low-temperature, low-humidity environment, the cleaning member becomes hard and the nip becomes difficult to form, making it easier for toner to slip through. Therefore, the higher the print coverage of the image, the more severe the evaluation of cleanability. In this evaluation, if the toner has poor cleanability, the paper dust, external additives, and toner that have slipped through the cleaning process will contaminate the charging roller, reducing the charging ability of the contaminated areas, resulting in the appearance of black vertical streaks when halftone images are output. Therefore, the number of vertical streaks that occurred on three halftone images obtained after the durability test was counted, and the cleaning ability in an extremely low temperature and low humidity environment was evaluated according to the following criteria. A score of C or higher was considered good. [Evaluation criteria] A. The width of the streaks is less than 0.5 mm, and the number of streaks is three or less. B. The width of the streaks is less than 0.5 mm, and the number of streaks is between 4 and 6. C. The width of the streaks is less than 0.5 mm, and the number of streaks is between 7 and 9. D. There are 10 or more streaks with a width of less than 0.5 mm, or streaks of 0.5 mm or more have occurred.

[0164] <Evaluation 6: Charge build-up in low temperature and low humidity environments> The main body and cartridge filled with toner were left in a low temperature and low humidity environment (temperature 15°C, humidity 5% RH) for one day, and then 40,000 sheets of horizontal line images with a printing rate of 1% were printed in intermittent mode under the above environment. After that, 20mm x 20mm solid black patches and 20mm x 20mm solid white patches were arranged alternately with a 5mm margin at the tip, and then a halftone image was output with the halftone image arranged over the entire surface (halftone image 2). The halftone densities at the positions where the second image of the solid black patch and solid white patch on the photosensitive drum is output (photosensitive drum pitch approximately 75.4 mm) were defined as the halftone density after solid black and the halftone density after solid white, respectively, and the charge rise property was evaluated from the difference between the two. A halftone image after a solid white image is formed with toner that has been rubbed repeatedly with a developing blade or developing roller to increase the amount of charge, whereas a halftone image after a solid black image is formed immediately after being charged once with a developing blade or developing roller. Therefore, in the case of toner with poor charge rising property, this appears as a difference in density between the half-tone density after solid black and the half-tone density after solid white. This evaluation is a strict evaluation of charge rise property, since charge rise property is likely to deteriorate in a low temperature and low humidity environment or after long-term use.

[0165] Specifically, for halftone image 2, the density of the halftone image after solid black was measured at 10 points between 99 mm and 119 mm from the leading edge of the paper, and the average value was calculated to be the halftone density after solid black. Similarly, the density of the halftone image after solid white was measured at 10 points, and the average value was calculated to be the halftone density after solid white. The evaluation criteria are as follows: C or above was considered good. [Evaluation criteria] A. The halftone density difference after durability is less than 0.05. B. The halftone density difference after durability testing is 0.05 or more and less than 0.10. C. The halftone density difference after durability test is 0.10 or more and less than 0.15. D. The halftone density difference after durability is 0.15 or more. [Table 6] In the table, evaluation 1 indicates the evaluation of cleaning performance in a low-temperature, low-humidity environment, evaluation 2 indicates the evaluation of fogging after durability in a low-temperature, low-humidity environment, Table 3 indicates the printing rate stability of cleaning in a low-temperature, low-humidity environment, evaluation 4 indicates the halftone reproducibility in a low-temperature, low-humidity environment, evaluation 5 indicates the evaluation of cleaning performance in an extremely low-temperature, low-humidity environment, and evaluation 6 indicates the charge rise property in a low-temperature, low-humidity environment.

[0166] Comparative Examples 1 to 11 In Comparative Examples 1 to 11, the above evaluations were carried out using toners 39 to 49, respectively. The evaluation results are shown in Table 6. [Explanation of symbols]

[0167] 1: Toner particle 1, 2: Toner particle 2, 3: Hydrotalcite particle A, 4: Toner particle Child boundary, 5: Analysis direction of line analysis

Claims

1. A toner comprising toner particles containing a binder resin, and fatty acid metal salt particles and hydrotalcite particles on the surfaces of the toner particles, the hydrotalcite particles contain fluorine and aluminum, In a line analysis of the STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, When the area ratio of the fatty acid metal salt particles to the toner particles in the EDS measurement field of view measured by STEM-EDS mapping analysis of the toner is S1 (%) and the area ratio of the hydrotalcite particles to the toner particles is H1 (%), S1 / H1 is 0.25 to 9.00, The toner has a ratio F / Al of the atomic concentration of fluorine to aluminum in the hydrotalcite particles, which is obtained from main component mapping of the hydrotalcite particles by STEM-EDS mapping analysis of the toner, of 0.01 to 0.

70.

2. A toner comprising toner particles containing a binder resin, and fatty acid metal salt particles and hydrotalcite particles on the surfaces of the toner particles, the hydrotalcite particles contain fluorine, In a line analysis of the STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, When the area ratio of the fatty acid metal salt particles to the toner particles in the EDS measurement field of view measured by STEM-EDS mapping analysis of the toner is S1 (%) and the area ratio of the hydrotalcite particles to the toner particles is H1 (%), S1 / H1 is 0.25 to 9.00, the product of the concentration of fluorine atoms in the hydrotalcite particles obtained from the main component mapping of the hydrotalcite particles by the STEM-EDS mapping analysis of the toner, H1, and 100 is defined as H2; When S2 is the product of the atomic number concentration of metal atoms in the fatty acid metal salt particles obtained from the main component mapping of the fatty acid metal salt particles by the STEM-EDS mapping analysis of the toner, S1, and 100, A toner having an S2 / H2 ratio of 0.10 to 18.

00.

3. A toner comprising toner particles containing a binder resin, and fatty acid metal salt particles and hydrotalcite particles on the surfaces of the toner particles, the hydrotalcite particles contain fluorine, In a line analysis of the STEM-EDS mapping analysis of the toner, fluorine is present inside the hydrotalcite particles, When the area ratio of the fatty acid metal salt particles to the toner particles in the EDS measurement field of view measured by STEM-EDS mapping analysis of the toner is S1 (%) and the area ratio of the hydrotalcite particles to the toner particles is H1 (%), S1 / H1 is 0.25 to 9.00, the toner particles contain at least one polyvalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron; In a main component mapping of the toner particles by STEM-EDS mapping analysis of the toner, the atomic concentration of the polyvalent metal element in the toner particles is 0.01 to 0.09, where the atomic concentration of carbon in the toner particles is taken as 100.

4. The toner according to claim 1, wherein the ratio F / Al of the atomic concentration of fluorine to aluminum in the hydrotalcite particles is 0.02 to 0.

60.

5. The hydrotalcite particles further contain aluminum, 4. The toner according to claim 2, wherein a value F / Al of the ratio of the atomic concentration of fluorine to aluminum in the hydrotalcite particles, obtained from main component mapping of the hydrotalcite particles by STEM-EDS mapping analysis of the toner, is 0.02 to 0.

60.

6. 6. The toner according to claim 1, wherein the number average particle diameter H3 (nm) of primary particles of the hydrotalcite particles is 40 nm to 1100 nm.

7. When the number average particle diameter of the primary particles of the fatty acid metal salt particles is S3 (nm) and the number average particle diameter of the primary particles of the hydrotalcite particles is H3 (nm), S3>H3 is satisfied, The toner according to any one of claims 1 to 6.

Images