Toner and two-component developer

Abstract

To provide a toner that has a high charge maintaining property for a long period and can suppress charging unevenness caused by transfer omission or member contamination even when aiming at higher image quality or higher speed.SOLUTION: A toner has toner particles and silica fine particles A on the surfaces of the toner particles. The weight average particle diameter of the toner is 4.0 to 15.0 μm, a carbon reduction rate when the silica fine particles A are cleaned with hexane is 5 to 70%, and under specific conditions, the silica fine particles A are heated to perform mass spectrometry at a sampling interval of 0.4 seconds, and a temperature at which a differential coefficient of a nine point moving average value of an integrated value obtained by integrating ionic intensity of an obtained mass number (M / z) 207 from 35°C becomes 4000 or more is 270°C or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to toners and two-component developers for developing electrostatic images used in electrophotography and electrostatic recording methods. [Background technology]

[0002] In recent years, electrophotographic full-color photocopiers have become widespread and are beginning to be applied to the printing market. The printing market demands high speed, high image quality, and high productivity through long continuous operation, while also supporting a wide range of media (paper types).

[0003] To improve image quality, it is necessary to stabilize the charging characteristics of the toner. Various external additives have been investigated to stabilize the charging characteristics of the toner. For example, Patent Document 1 discloses a toner in which the charging characteristics are improved by adding silica particles whose surface has been treated with a cyclic siloxane. Patent Document 2 discloses a toner having a cyclic siloxane on its surface. Furthermore, in order to achieve even higher image quality, there is a need for a toner that does not have gaps during transfer and has high transfer efficiency. For example, Patent Document 3 discloses a toner that has high transfer efficiency by externally adding inorganic fine powder treated with silicone oil on its surface. Furthermore, in order to achieve high productivity through long-term continuous operation, studies are being conducted to suppress contamination of components by external additives. Patent Document 4 discloses a toner to which silica particles, whose surface has been treated with a silane coupling agent and then with silicone oil, are externally added. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2016-167029 [Patent Document 2] Japanese Patent Publication No. 2009-031426 [Patent Document 3] Japanese Patent Application Publication No. 9-204065

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when aiming for application to the printing market, it is necessary to satisfy higher levels of high speed, high image quality, and high productivity through continuous operation for a long time. Therefore, the toner is required to have higher charge retention than conventional ones.

[0006] On the other hand, in a high-speed copier used in the printing market, a corona charger that is non-contact with the photoreceptor may be used as a charger. Since the corona charger is non-contact with the photoreceptor, it has the advantage of being advantageous for member contamination because it does not contact toner, silica fine particles, etc. on the photoreceptor. However, when aiming for higher levels of high speed, high image quality, and high productivity through continuous operation for a long time, in the charging process, larger discharges occur for a long time. As a result, when inorganic fine powders such as silica fine particles are present on the photoreceptor, they receive higher discharge energy than conventional ones. At this time, when the surface of the inorganic fine powder is treated with silicone oil to suppress dropout during transfer and achieve high transfer efficiency, the silicone oil that has received high discharge energy volatilizes and peels off from the surface of the inorganic fine powder, and may adhere to and contaminate members such as the charger. As a result, charge unevenness may occur on the photoreceptor, and the in-plane uniformity of the image may decrease.

[0007] The toner disclosed in the above document was insufficient to satisfy all of the long-term charge retention of the toner, suppression of dropout during transfer, and suppression of charge unevenness due to member contamination when aiming for further improvement in image quality and speed.

[0008] The present disclosure provides a toner that has high charge retention over a long period of time and can suppress charge unevenness due to dropout during transfer and member contamination even when aiming for further improvement in image quality and speed.

Means for Solving the Problems

[0009] The present disclosure relates to a toner having toner particles and silica fine particles A on the surface of the toner particles, where the weight average particle diameter of the toner is 4.0 to 15.0 μm, the carbon reduction rate when the silica fine particles A are washed with hexane is 5 to 70%, while heating the silica fine particles A under the following conditions, mass spectrometry is performed at a sampling interval of 0.4 seconds, and the temperature at which the differential coefficient of the nine-point moving average value of the integrated value integrated from 35°C for the ion intensity of mass number (M / z) 207 obtained is 4000 or more is 270°C or higher. The present disclosure relates to a toner. Mass spectrometry conditions: (i) Under a nitrogen atmosphere, 7.0 mg of the silica fine particles A are heated from 35°C at a heating rate of 20°C / min. (ii) The gas generated with the temperature increase is ionized under the conditions of an ionization current of 50 μA and an ionization energy of 70 eV. (iii) For the components contained in the ionized gas, mass spectrometry is performed using a quadrupole mass spectrometer under the condition of an EM voltage of 1000 V.

Advantages of the Invention

[0010] According to the present disclosure, even when aiming for further high image quality and high speed, it is possible to provide a toner that has high charge retention over a long period and can suppress charge unevenness due to dropout during transfer or member contamination.

Brief Description of the Drawings

[0011] [Figure 1] Schematic diagram for calculating the embedding rate [Figure 2] Schematic diagram of the heat treatment apparatus

Embodiments for Carrying Out the Invention

[0012] In this disclosure, descriptions indicating numerical ranges such as "XX or more and YY or less" or "XX to YY" mean a numerical range that includes the lower and upper limits, unless otherwise specified. When numerical ranges are described in steps, the upper and lower limits of each numerical range can be combined in any way. Furthermore, a monomer unit refers to the reacted form of monomer material in a polymer.

[0013] The inventors diligently studied toners that could maintain high charge retention over long periods, even when aiming for further improvements in image quality and speed, and that could suppress uneven charging due to transfer gaps and material contamination. As a result, they found that the above problems could be solved with the following toner.

[0014] This disclosure relates to a toner having toner particles and silica fine particles A on the surface of the toner particles, The weight-average particle size of the toner is 4.0 to 15.0 μm. The carbon reduction rate when the silica fine particles A are washed with hexane is 5-70%. Under the following conditions, mass spectrometry was performed on the silica nanoparticles A while heating them at a sampling interval of 0.4 seconds. The temperature at which the derivative of the 9-point moving average of the integral values ​​obtained from 35°C for the ionic intensity of mass number (M / z) 207 becomes 4000 or more is 270°C or higher. Regarding - Mass spectrometry conditions: (i) Heat 7.0 mg of silica fine particles A in a nitrogen atmosphere at a heating rate of 20°C / min from 35°C. (ii) The gas generated as the temperature rises is ionized under conditions of an ionization current of 50 μA and an ionization energy of 70 eV. (iii) The components contained in the ionized gas are subjected to mass spectrometry using a quadrupole mass spectrometer under the condition of an EM voltage of 1000V.

[0015] We believe the reasons for the above effects are as follows: Ions with a mass number (M / z) of 207 are characteristically observed when compounds with a siloxane structure, such as silicone oil, are decomposed and ionized by heat. When analyzing the ionic intensity of ions with a mass number (M / z) of 207 while increasing the temperature using the method described above, if the derivative (slope of the graph) of the nine-point moving average of the integral values ​​integrated from 35°C is 4000 or more, it indicates that at that temperature, compounds with a siloxane structure are detached from the surface of silica nanoparticles A by thermal energy, decomposed, and ionized. In other words, a derivative coefficient (graph slope) of 4000 or more indicates that a compound having a siloxane structure, such as silicone oil, is present on the surface of the silica nanoparticle A. Furthermore, in the toner of this disclosure, the temperature at that time must be 270°C or higher.

[0016] The ease with which compounds having a siloxane structure, such as silicone oil, can be peeled off from the surface of silica nanoparticles A is thought to be proportional to the strength of the interaction between the compound having a siloxane structure and the surface of silica nanoparticles A.

[0017] The higher the temperature, the stronger the interaction between the siloxane-structured compound, such as silicone oil, and the surface of the silica nanoparticles A, and it is thought that the siloxane-structured compound is firmly retained on the surface of the silica nanoparticles A. As a result, when aiming for even higher image quality and higher speed, even when subjected to higher discharge energy during the charging process, the siloxane-structured compound present on the surface of the silica nanoparticles A does not peel off due to the discharge energy and can remain on the surface of the silica nanoparticles A.

[0018] Therefore, this disclosure can suppress contamination of components by compounds having a siloxane structure, such as silicone oil, which could not be suppressed with conventional silica nanoparticles. The temperature at which the derivative coefficient (graph slope) of the 9-point moving average of the integral values ​​obtained by integrating the ionic strength of mass number (M / z) 207 from 35°C reaches 4000 is more preferably 300°C or higher, and even more preferably 320°C or higher. Furthermore, the upper limit is preferably 500°C or less, more preferably 400°C or less, and even more preferably 360°C or less. When the upper limit is 500°C or less, it indicates that compounds having a siloxane structure, such as silicone oil, are held and present on the surface of silica fine particles with appropriate strength, improving the release properties of the toner. As a result, even when aiming for higher image quality or faster transfer speeds, transfer dropouts can be further suppressed.

[0019] Furthermore, the fact that the surface of silica nanoparticles A is less susceptible to change even when subjected to stronger energy means that, even when aiming for higher image quality or higher speed, the charge state of the toner surface remains constant and the charged state is stable over the long term. As a result, the charge retention performance is improved. The temperature at which the above derivative (graph slope) reaches 4000 is controlled by the type and amount of surface treatment agent containing siloxane bonds, the temperature and treatment time during surface treatment, the viscosity and amount of silicone oil, and the temperature and treatment time when surface treatment with silicone oil, as described later. It is possible. Specifically, the temperature at which the above derivative (graph slope) reaches 4000 can be increased by using a surface treatment agent containing siloxane bonds of an appropriate chain length and setting the surface treatment temperature to 300°C or higher, preferably 330°C or higher. Alternatively, the temperature can be increased by setting the surface treatment temperature with silicone oil to 220°C or higher, preferably 300°C or higher, more preferably 330°C or higher.

[0020] Furthermore, the carbon reduction rate when silica nanoparticles A are washed with hexane is 5-70%. The reduction in carbon when washed with hexane indicates that compounds having a siloxane structure, such as the aforementioned silicone oil, are present on the surface of silica nanoparticles A in a state that can be released by hexane. In other words, even though compounds having a siloxane structure are present on the surface of silica nanoparticles A in a state that can be released, it is thought that the compounds having a siloxane structure are firmly retained on the surface of silica nanoparticles A due to the strong interaction between the compounds having a siloxane structure and the surface of silica nanoparticles A.

[0021] By controlling the carbon reduction rate during hexane washing to 5-70%, a compound with a siloxane structure, such as silicone oil, can be attached to the surface of silica nanoparticles A with appropriate strength, improving the toner's release properties. As a result, even when aiming for higher image quality or faster transfer speeds, transfer dropouts can be suppressed.

[0022] By keeping the carbon reduction rate within the above range, compounds with a siloxane structure, such as silicone oil, are more appropriately retained on the silica surface. When the carbon reduction rate is 70% or less, even when high discharge energy is applied during the charging process, compounds with a siloxane structure, such as silicone oil, present on the surface of the silica nanoparticles become even less likely to peel off due to the discharge energy. Therefore, compounds with a siloxane structure, such as silicone oil, tend to remain on the surface of silica nanoparticles A, suppressing contamination of the material.

[0023] Furthermore, when the carbon reduction rate is 5% or more, a compound having a siloxane structure, such as silicone oil, adheres to the surface of silica nanoparticles A with appropriate strength, thereby suppressing data loss during transfer. In addition, the charge state on the surface of the toner is kept more constant, and the charged state becomes more stable, improving charge retention. When silica fine particles A are washed with hexane, a carbon reduction rate of 30-55% is more preferable.

[0024] The carbon reduction rate can be controlled by a two-stage surface treatment using a surface treatment agent containing siloxane bonds and silicone oil, as well as by the temperature and treatment time during the surface treatment and the amount of silicone oil used. The carbon reduction rate can be increased by lowering the treatment temperature of the silicone oil or increasing the amount of silicone oil used. On the other hand, the carbon reduction rate can be decreased by raising the treatment temperature of the silicone oil or decreasing the amount of silicone oil used.

[0025] When measuring the physical properties of the silica fine particles A described above, if it is necessary to separate the silica fine particles A from the toner particles, the measurements can be taken after separation using the method described later. In the separation method described later, since the separation is performed in an aqueous medium, the hydrophobic treatment agent (e.g., silicon compound) does not dissolve into the medium, and the silica fine particles A can be separated from the toner particles while maintaining the physical properties before the separation process. Therefore, the values ​​of each physical property measured using the silica fine particles A separated from the toner particles will be substantially the same as the values ​​of each physical property measured using the silica fine particles A before external addition.

[0026] The weight-average particle size (D4) of the toner is 4.0 to 15.0 μm. By being within this range, the silica microparticles A possessing the above characteristics can properly cover the toner surface, allowing the effects of silica microparticles A to be exerted. As a result, even when aiming for further improvements in image quality and speed, it is possible to obtain a toner that maintains high charge retention over a long period of time and can suppress charge unevenness caused by transfer gaps and material contamination. The weight-average particle size (D4) of the toner is preferably 5.0 to 10.0 μm, and more preferably 6.0 to 8.0 μm.

[0027] <Method for analyzing the ionic strength of an ionic with mass number (M / z) 207> The ionic intensity of mass number (M / z) 207 is analyzed using a thermogravimetric-mass spectrometer "TG-MS" (JEOL Ltd., quadrupole mass spectrometer JMS-Q1500GC + STA2500 Regulus). The measurement conditions are as follows. (Measurement conditions) • Amount of silica microparticles A: 7.0 mg ·Measurement start temperature: 35℃ • Heating rate: 20°C / min • TG-MS measurement atmosphere: Nitrogen Ion source temperature: 250℃ Ionization current: 50 μA Ionization energy: 70 eV EM voltage: 1000V • Data sampling interval: 0.4 seconds

[0028] Furthermore, the ionic intensity of mass number (M / z) 207 obtained by the above measurement is analyzed using the following method to obtain the temperature at which the derivative (graph slope) of the 9-point moving average of the integral values ​​integrated from 35°C is 4000 or more. (Analysis conditions) The average ionic intensity of ions with a mass number (M / z) of 207 at temperatures between 35°C and 100°C is calculated and used as the background value. • From the ion intensity at each temperature above 35°C, determine the temperature at which the derivative (slope of the graph) of the 9-point moving average of the integral value of the ion intensity (after subtracting the background value) is 4000 or greater.

[0029] <Separation of silica fine particles A from toner> The following procedure can be used to measure various physical properties of silica fine particles A separated from the toner. Weigh 20g of a 10% aqueous solution of "Contaminon N" (a pH 7 neutral detergent for cleaning precision measuring instruments consisting of a nonionic surfactant, anionic surfactant, and organic builder) into a 50mL vial and mix with 1g of toner. Place the toner in the "KM Shaker" (model: V.SX) manufactured by Iwaki Sangyo Co., Ltd., set the speed to 50, and shake for 30 seconds. This will cause the silica microparticles to migrate from the surface of the toner particles to the aqueous solution. Subsequently, in the case of magnetic toner containing magnetic material, the toner particles are restrained using a neodymium magnet, and the silica microparticles that have migrated to the supernatant liquid are separated and dried under vacuum (40°C / 24 hours) to obtain silica microparticles. In the case of non-magnetic toner, the toner particles and the silica microparticles that have migrated to the supernatant liquid are separated using a centrifuge (H-9R; manufactured by Kokusan Co., Ltd.) (at 1000 rpm for 5 minutes).

[0030] If external additives other than silica microparticles A are added to the toner, the external additives separated from the toner by the method described above are subjected to centrifugal separation to separate silica microparticles A from the other external additives. It is possible to separate them. Even if multiple types of silica particles are added to the toner, if they have different particle size ranges, they can be separated by centrifugal separation. For example, separation can be performed using a CS120FNX (manufactured by Hitachi Koki Co., Ltd.) at 40,000 rpm for 20 minutes.

[0031] <Measurement of carbon loss rate when silica microparticles A are washed with hexane> 1.0 g of silica nanoparticles is weighed into a 50 ml screw-cap tube, and 20 ml of n-hexane is added. Then, the sample is extracted for 10 minutes at an intensity of 20 (output 10 W) using an ultrasonic homogenizer (TAITEC VP-050). The resulting extract is separated using a centrifuge, the supernatant is removed, and the n-hexane is removed from the resulting wet sample using an evaporator to obtain silica particles after hexane washing. The carbon content of silica particles before and after hexane washing is measured using a total nitrogen / total carbon analyzer (Sumigraph NC-22F, manufactured by Sumika Analysis Center), and the carbon reduction rate (%) is calculated using the following formula. Carbon reduction rate (%) = {(Carbon content of silica particles before hexane washing (mass%)) - (Carbon content of silica particles after hexane washing (mass%))} / (Carbon content of silica particles before hexane washing (mass%) × 100)

[0032] <Method for measuring the weight-average particle size (D4) of toner> The weight-average particle size (D4) of the toner is measured using the Coulter Multisizer, a precision particle size distribution analyzer with a pore electrical resistance method equipped with a 100 μm aperture tube. Using the "Beckman Coulter Multisizer 3" (registered trademark, manufactured by Beckman Coulter) and the accompanying dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) for setting measurement conditions and analyzing measurement data, measurements are taken with an effective number of measurement channels of 25,000, and the measurement data is analyzed and calculated. The electrolytic aqueous solution used for measurement is prepared by dissolving special grade sodium chloride in deionized water to a concentration of approximately 1% by mass; for example, "ISOTON II" (manufactured by Beckman Coulter) can be used. Before performing measurements and analysis, configure the dedicated software as follows. In the dedicated software's "Change Standard Measurement Method (SOM)" screen, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard 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, the electrolyte to ISOTON II, and check the box for flushing the aperture tube after measurement. In the dedicated software's "Pulse to Particle Size Conversion Settings Screen," set the bin spacing to logarithmic particle size, the particle size bins to 256 particle size bins, and the particle size range to 2 μm or more and 60 μm or less.

[0033] The specific measurement method is as follows: (1) Pour approximately 200 ml of the electrolytic solution into a 250 ml round-bottom glass beaker specifically designed for the Multisizer 3, set it on the sample stand, and stir the mixture with the stirrer rod at 24 revolutions per second in a counterclockwise direction. Then, use the "Aperture Tube Flash" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube. (2) Place approximately 30 ml of the electrolytic aqueous solution into a 100 ml flat-bottomed glass beaker, and add approximately 0.3 ml of a diluted solution of "Contaminon N" (a 10% by mass 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.) diluted three times by mass with deionized water as a dispersant. (3) Two oscillators with an oscillation frequency of 50 kHz are built in with a phase difference of 180 degrees, and a predetermined amount of ions are exchanged in the water tank of the "Ultrasonic Dispersion System Tetora150" (manufactured by Nikko Bios Co., Ltd.), which has an electrical output of 120 W. Add a change of water, and then add approximately 2 ml of the aforementioned Contaminon N to the tank. (4) Place the beaker from (2) into the beaker fixing hole of the ultrasonic disperser and operate the ultrasonic disperser. Then, adjust the height of the beaker so that the resonance state of the liquid surface of the electrolytic aqueous solution inside the beaker is maximized. (5) While irradiating the electrolytic aqueous solution in the beaker described in (4) with ultrasound, add approximately 10 mg of toner to the electrolytic aqueous solution in small amounts and disperse it. Continue the ultrasonic dispersion treatment for another 60 seconds. During ultrasonic dispersion, adjust the water temperature in the tank to be between 10°C and 40°C as appropriate. (6) Using a pipette, the electrolytic aqueous solution (5) containing the dispersed toner is dropped into the round-bottom beaker (1) placed in the sample stand, and the concentration is adjusted to approximately 5%. The measurement is then continued until the number of particles measured reaches 50,000. (7) The measurement data is analyzed using the dedicated software attached to the device, and the weight-average particle size (D4) is calculated. Note that the "Average Diameter" on the Analysis / Volume Statistics (Arithmetic Mean) screen when the dedicated software is set to Graph / Volume % is the weight-average particle size (D4).

[0034] For the reasons stated above, even when aiming for further improvements in image quality and speed, it is possible to obtain a toner that maintains high charge retention over a long period of time and can suppress uneven charging due to transfer gaps and material contamination.

[0035] Furthermore, the BET specific surface area of ​​silica nanoparticle A at a temperature of 30°C and relative humidity of 80% is 1 m². 2 The amount of water absorbed per unit is 0.01 to 0.07 cm. 3 / m 2 Preferably, 0.01 to 0.05 cm 3 / m 2 More preferably, 0.02-0.03 cm 3 / m 2 That is even more preferable.

[0036] The amount of moisture adsorbed by silica nanoparticles A is influenced by the surface condition of silica nanoparticles A. The fact that the amount of moisture adsorbed by silica nanoparticles A falls within the aforementioned range indicates that the surface of silica nanoparticles A has appropriate hydrophobicity. This means that siloxane chains have bonded to the silanol groups present on the surface of the silica nanoparticle substrate, resulting in fewer silanol groups remaining on the surface. Therefore, the moderately adsorbed moisture suppresses excessive charging in low-humidity environments while also suppressing a decrease in charging in high-humidity environments. As a result, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving the charge retention.

[0037] The amount of moisture adsorbed by silica nanoparticles A can be controlled by the type and amount of surface treatment agent containing siloxane bonds, the temperature and treatment time during surface treatment, etc. Specifically, it can be reduced by increasing the amount of surface treatment agent containing siloxane bonds, raising the temperature during surface treatment, or lengthening the treatment time.

[0038] <Method for measuring water adsorption amount> The amount of moisture adsorbed by silica nanoparticles A is measured using an adsorption equilibrium measuring device (BELSORP-aqua3: manufactured by Nippon Bell Co., Ltd.). This device measures the amount of adsorbed gas (water vapor) of the target gas.

[0039] (Degassing) Before measurement, degas the moisture adsorbed on the sample. Attach the cell, filler lot, and cap, and measure the empty weight. Weigh 0.3 g of the sample and put it into the cell. Put the filler lot into the cell, attach the cap, and attach it to the degassing port. When all the cells to be measured are attached to the degassing port, open the helium valve. Turn on the button of the degassing port and press the "VAC" button. Then perform degassing for more than one day.

[0040] (Measurement) Turn on the power of the fixed part main body (there is a switch on the back side of the main body). At the same time, start the vacuum pump. Turn on the power of the main body for circulating water and the operation panel. Launch "BELaqua3.exe" (measurement software) in the center of the PC screen. Temperature control of the air high-temperature bath: Double-click "SV" in the frame of "TIC1" on the "Flow Diagram" window to open the "Temperature Setting" window. Enter the temperature (80 °C) and click "Set". Control of the adsorption temperature: Double-click "SV" of "Adsorption Temperature" in the "Flow Diagram" window and enter the "SV value" (adsorption temperature). Click "Circulation Start" and "External Temperature Control", and then click "Set". Press the "PURGE" button to stop degassing, turn off the button of the port, remove the sample, attach cap 2, measure the weight of the sample, and then attach the sample to the main body measurement part. On the PC, click "Measurement Conditions" to open the "Measurement Condition Setting" window. The measurement conditions are as follows.

[0041] Air constant temperature bath temperature: 80.0 °C, adsorption temperature: 30.0 °C, adsorbed substance name: H2O, equilibrium time: 500 sec, temperature waiting time: 60 min, saturated vapor pressure: 4.245 kPa, sample tube exhaust speed: normal, chemical adsorption measurement: not performed, initial introduction amount: 0.20 cm 3 (STP)·g -1 , measurement relative pressure range number: 4 Select the number of measurement specimens and enter the "Measurement Data File Name" and "Sample Weight". Start the measurement. (Analysis) Launch the analysis software and perform analysis. Determine the moisture adsorption amount at a relative water vapor pressure of 80%.

[0042] The BET specific surface area of ​​silica nanoparticle A is 60-160 m². 2 / g is preferred, and 70-160m 2 / g is preferable. Because the BET specific surface area of ​​silica nanoparticles A is within the aforementioned range, silica nanoparticles A can properly coat toner particles, allowing them to exhibit their full potential. As a result, even when high discharge energy is applied during the charging process, compounds with a siloxane structure present on the surface of silica nanoparticles A remain more easily, becoming less susceptible to peeling due to the discharge energy, and further suppressing contamination of the material. Furthermore, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving charge retention. In addition, compounds with a siloxane structure are appropriately free on the surface of silica fine particles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and higher speed, transfer dropouts can be further suppressed.

[0043] <Measurement of BET specific surface area of ​​silica microparticles> The BET specific surface area can be determined by the BET method (BET multi-point method) using a low-temperature gas adsorption method with a dynamic constant-pressure approach. By using a specific surface area measuring device (product name: Gemini 2375 Ver. 5.0, manufactured by Shimadzu Corporation), nitrogen gas is adsorbed onto the sample surface, and the BET specific surface area (m²) is measured using the BET multi-point method. 2 It is possible to calculate ( / g).

[0044] The amount of carbon-based free components in the silica fine particles A used in the present invention is preferably 3.0 parts by mass or more and 9.0 parts by mass or less, more preferably 5.0 parts by mass or more and 8.0 parts by mass or less, and even more preferably 6.0 to 8.0 parts by mass, per 100 parts by mass of silica fine particles A. By keeping the amount of free components within the above range, compounds having a siloxane structure are appropriately free on the surface of silica fine particles A, improving the release properties of the toner. As a result, even when aiming for further improvements in image quality and speed, transfer dropouts can be suppressed.

[0045] Furthermore, by keeping the amount of free components within the above range, compounds having a siloxane structure are more appropriately retained on the surface of silica nanoparticles A. As a result, even when high discharge energy is applied during the charging process, compounds having a siloxane structure present on the surface of silica nanoparticles A become less likely to peel off due to the discharge energy and can remain on the surface of the silica nanoparticles, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant and the charged state becomes more stable, further improving charge retention.

[0046] The amount of the above-mentioned free components can be controlled by a two-step surface treatment using a surface treatment agent containing siloxane bonds and silicone oil, as well as by the temperature and treatment time during the surface treatment and the amount of silicone oil used. Specifically, the amount of free components based on carbon in silica nanoparticles A can be increased by lowering the processing temperature of the silicone oil or increasing the amount of silicone oil processed. Conversely, the amount of free components based on carbon in silica nanoparticles A can be decreased by raising the processing temperature of the silicone oil or decreasing the amount of silicone oil processed.

[0047] <Method for measuring the amount of free components based on carbon in silica microparticles A> The amount of free components based on carbon in silica nanoparticles A can be determined by measuring the amount of silicone oil that dissolves when the nanoparticles are immersed in n-hexane. Specifically, 0.5 g of silica microparticles A and 32 ml of n-hexane are placed in a 50 ml centrifuge tube, and ultrasonically dispersed for 30 minutes using an ultrasonic cleaner (Yamato Scientific 1510JMTH) to suspend the particles. The resulting suspension is centrifuged to separate and recover the solid phase (silica). Another 32 ml of n-hexane is added to the recovered silica, and the ultrasonic dispersion and centrifugation operations are repeated a total of three times. Finally, the mixture is dried under reduced pressure (120°C, 12 hours) to obtain a dried powder. The carbon content of this powder is measured using a total nitrogen / total carbon analyzer (Sumigraph NC-22F, manufactured by Sumika Analysis Center). The total carbon content of 0.5 g of the sample is measured beforehand, and the amount of extracted free components is calculated from the difference between this total carbon content and the measured amount.

[0048] It is preferable that silica nanoparticles A have a compound having a siloxane structure on their surface. It is preferable that silica nanoparticles A are obtained by mixing a silica nanoparticle substrate with a surface treatment agent containing siloxane bonds, heat-treating the mixture, and then treating it with silicone oil. In this disclosure, when silica nanoparticles A are surface-treated with a surface treatment agent such as silicone oil, the portion derived from the surface treatment agent is also referred to as silica nanoparticles A. Silica nanoparticles before surface treatment may also be referred to as "silica nanoparticle substrate".

[0049] A method for manufacturing toner preferably includes the steps of obtaining silica fine particles A and mixing the silica fine particles A with toner particles to obtain toner. Furthermore, a method for manufacturing toner preferably includes the step of preparing the silica fine particles A obtained in the following steps. The step of obtaining silica fine particles A is preferably: A step of mixing a silica microparticle substrate with a surface treatment agent containing siloxane bonds (preferably a cyclic siloxane), and performing a heat treatment at a temperature of 295°C or higher (preferably 300°C or higher) to obtain a surface-treated product of the silica microparticle substrate with the surface treatment agent containing siloxane bonds, and The process includes a step of further surface-treating the surface-treated material with silicone oil to obtain silica fine particles A.

[0050] The surface treatment agent containing siloxane bonds is not particularly limited, and known materials can be used. To easily obtain the above physical properties, it is preferable to perform a surface treatment on the silica fine particle substrate.

[0051] Surface treatment agents containing siloxane bonds include, for example, silicone oils such as dimethyl silicone oil; silicone oils in which the side chains or terminals of dimethyl silicone oil are modified with organic groups, such as methyl hydrogen silicone oil, methylphenyl silicone oil, alkyl-modified silicone oil, chloroalkyl-modified silicone oil, chlorophenyl-modified silicone oil, fatty acid-modified silicone oil, polyether-modified silicone oil, alkoxy-modified silicone oil, carbinol-modified silicone oil, amino-modified silicone oil, and fluorine-modified silicone oil; and cyclic siloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane. The surface treatment agent containing siloxane bonds is preferably a cyclic siloxane. More preferably, it is a cyclic siloxane with up to 10 membered rings. The cyclic siloxane may have substituents on some of the methyl groups bonded to the silicon atoms. Silica fine particles A is preferably a silicone oil-treated product of silica fine particles treated with a cyclic siloxane. The cyclic siloxane is preferably at least one selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane. The cyclic siloxane is more preferably octamethylcyclotetrasiloxane.

[0052] The method for surface treatment of the silica microparticle substrate is not particularly limited and can be carried out by contacting the silica microparticle substrate with a surface treatment agent containing siloxane bonds. From the viewpoint of uniformly treating the surface of the silica microparticle substrate and easily achieving the above physical properties, it is preferable to contact the silica microparticle substrate with the surface treatment agent in a dry manner. As will be described later, examples of methods include contacting the silica microparticle substrate with the vapor of the surface treatment agent, or spraying the silica microparticle substrate with the undiluted solution or a diluted solution of the surface treatment agent with various solvents. The processing temperature is not particularly limited, as it varies depending on the reactivity of the surface treatment agent used. It is preferable to mix the silica fine particle substrate and the surface treatment agent and heat-treat them at a temperature of 300°C or higher. More preferably, it is between 300°C and 380°C.

[0053] The processing time varies depending on the processing temperature and the reactivity of the surface treatment agent used, but is preferably 5 minutes to 300 minutes, more preferably 30 minutes to 240 minutes, and even more preferably 60 minutes to 200 minutes. The processing temperature and processing time for surface treatment being within the above range is preferable from the viewpoint of allowing the treatment agent to react sufficiently with the silica fine particle substrate, and from the viewpoint of production efficiency.

[0054] For contact between the surface treatment agent and the silica microparticle substrate, it is preferable to contact the surface treatment agent vapor under reduced pressure or in an inert gas atmosphere such as a nitrogen atmosphere. By using the vapor contact method, it is easy to remove surface treatment agents that do not react with the silica microparticle surface, and the surface of the silica microparticles can be appropriately coated with modifying groups having appropriate polarity. When using the vapor contact method, it is preferable to perform the treatment at a treatment temperature above the boiling point of the surface treatment agent. The vapor contact may be carried out in multiple steps (for example, 2 to 3 times). Silica fine particles A are obtained by treating a silica fine particle substrate with a cyclic siloxane, and it is more preferable that the treatment temperature of the cyclic siloxane is 300°C or higher.

[0055] Since cyclic siloxanes react with silanol groups on the surface of the silica nanoparticle substrate via a ring-opening reaction, the surface of silica nanoparticles A can be more effectively coated with modifying groups having appropriate polarity. This allows for controlling the interaction between the compound having a siloxane structure and the surface of silica nanoparticles A to an appropriate strength. Therefore, it is easier to raise the temperature at which the differential coefficient exceeds 4000. In addition, it becomes easier to control the carbon reduction rate during washing with hexane within a suitable range.

[0056] On the other hand, the ring-opening reaction between the cyclic siloxane and the silanol groups on the surface of the silica nanoparticle substrate is accompanied by The silanol groups at the end of the modifying groups derived from the cyclic siloxane that are generated tend to become reaction sites with the cyclic siloxane, leading to longer chain lengths. A processing temperature of 300°C or higher is preferable because it allows for the formation and cleavage of siloxane bonds, enabling uniform control of the chain length. With a uniform chain length, the surface of the silica nanoparticles A can be more appropriately coated with modifying groups having appropriate polarity. By covering the surface of the silica nanoparticle substrate with modifying groups of appropriate chain length, the interaction between the cyclic siloxane modifying groups and the silicone oil during subsequent silicone oil treatment is expected to become stronger. Therefore, it becomes easier to raise the temperature at which the differential coefficient exceeds 4000. Furthermore, it becomes easier to control the carbon reduction rate during hexane washing within a suitable range.

[0057] As a result, even when high discharge energy is applied during the charging process, the silicone oil present on the surface of silica nanoparticles A becomes even less likely to peel off due to the discharge energy, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving charge retention. Furthermore, compounds with a siloxane structure are appropriately free on the surface of silica nanoparticles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and higher speed, transfer dropouts can be further suppressed.

[0058] Among cyclic siloxanes, octamethylcyclotetrasiloxane is more preferred from the viewpoint of ease of controlling the chain length of the modifying groups on the surface of silica nanoparticles A and ease of purification. By using octamethylcyclotetrasiloxane, the chain length of the modifying groups on the surface of silica nanoparticles A can be controlled more uniformly, and the surface of silica nanoparticles A can be more appropriately covered with modifying groups having appropriate polarity. Therefore, it is easier to raise the temperature at which the differential coefficient exceeds 4000. In addition, it becomes easier to control the carbon reduction rate during washing with hexane to a suitable range.

[0059] As a result, even when high discharge energy is applied during the charging process, the silicone oil present on the surface of silica nanoparticles A becomes even less likely to peel off due to the discharge energy, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving the charge retention performance. Furthermore, compounds having a siloxane structure are appropriately free on the surface of silica microparticles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and faster transfer speeds, transfer dropouts can be further suppressed.

[0060] The amount of surface treatment agent is preferably 40 to 150 parts by mass, and more preferably 70 to 140 parts by mass, per 100 parts by mass of silica microparticle substrate. In particular, when surface treatment is performed by contacting with a cyclic siloxane using vapor, it is preferable to add 100 parts by mass or more per 100 parts by mass of silica microparticle substrate. This allows for more uniform surface treatment of the silica microparticle substrate, and thus the surface of the silica microparticles can be more appropriately covered with modifying groups having appropriate polarity. As a result, it is easier to raise the temperature at which the differential coefficient exceeds 4000. In addition, it becomes easier to control the carbon reduction rate during washing with hexane within a suitable range.

[0061] As a result, even when high discharge energy is applied during the charging process, the silicone oil present on the surface of silica nanoparticles A tends to remain, becoming even less prone to peeling due to the discharge energy, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving charge retention. Furthermore, compounds with a siloxane structure are appropriately free on the surface of silica nanoparticles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and higher speed, transfer dropouts can be further suppressed.

[0062] Furthermore, when performing surface treatment under reduced pressure, the pressure due to the vapor of the surface treatment agent inside the container should be 0.1 The pressure is preferably between Pa and 100 Pa, and more preferably between 1.0 Pa and 10 Pa. By setting the pressure within this range, the frequency of contact between vapor molecules of the surface treatment agent is reduced, suppressing chemical reactions between the surface treatment agents and allowing the chemical reaction between the surface treatment agent in contact with the surface of the silica fine particle substrate to proceed preferentially. Furthermore, reaction byproducts generated by the chemical reaction between the silica microparticle substrate and the surface treatment agent can be easily removed from the vicinity of the silica microparticle surface, allowing the surface treatment agent to come into closer contact with the surface of the silica microparticle substrate, and enabling more uniform surface treatment of the silica microparticle substrate.

[0063] Furthermore, when performing surface treatment under reduced pressure, it is preferable to perform a degassing treatment by heating the silica microparticle substrate under reduced pressure to remove moisture and other substances adsorbed on the surface of the silica microparticle substrate before bringing the surface treatment agent into contact with the surface of the silica microparticle substrate. This makes it easier for the surface treatment agent to come into contact with the surface of the silica microparticles, allowing for more uniform surface treatment of the silica microparticle substrate. In addition, from the viewpoint of making it easier for the surface treatment agent to come into contact with the surface of the silica microparticle substrate, it is also preferable to repeat the degassing treatment and the surface treatment of the silica microparticles with the surface treatment agent.

[0064] It is preferable to mix a silica microparticle substrate with a surface treatment agent containing siloxane bonds and heat-treat the mixture, and then further treat the silica microparticle substrate with silicone oil. The second reaction, the heat treatment with silicone oil, is preferably performed at a temperature of 300°C or higher. In other words, it is preferable that the temperature when the surface-treated material is further treated with silicone oil is 300°C or higher. By using a processing temperature of 300°C or higher, the surface of the silica nanoparticles treated with cyclic siloxane and the silicone oil become more uniformly compatible, and the interaction between the cyclic siloxane-modified groups on the silica nanoparticle surface and the silicone oil becomes stronger. Therefore, it is easier to raise the temperature at which the differential coefficient exceeds 4000. In addition, it becomes easier to control the carbon reduction rate during washing with hexane within a suitable range.

[0065] As a result, even when high discharge energy is applied during the charging process, the silicone oil present on the surface of silica nanoparticles A tends to remain, becoming even less likely to peel off due to the discharge energy, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving charge retention. Furthermore, compounds having a siloxane structure are appropriately free on the surface of silica microparticles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and faster transfer speeds, transfer dropouts can be further suppressed.

[0066] The treatment time for the silicone oil is preferably 40 minutes to 150 minutes, and more preferably 60 minutes to 120 minutes, in order to uniformly treat the silica surface. The amount of silicone oil added is preferably 3 to 25 parts by mass, and more preferably 5 to 20 parts by mass, per 100 parts by mass of the silica nanoparticle substrate. By using the above amount, it is possible to uniformly treat the surface of the silica nanoparticles A while effectively obtaining interaction with the cyclic siloxane modifying groups on the surface of the silica nanoparticles A. Therefore, it is easy to raise the temperature at which the differential coefficient exceeds 4000. In addition, it becomes easier to control the carbon reduction rate during washing with hexane within a suitable range.

[0067] As a result, even when high discharge energy is applied during the charging process, the silicone oil present on the surface of silica nanoparticles A tends to remain, becoming even less likely to peel off due to the discharge energy, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving charge retention. Furthermore, compounds having a siloxane structure are appropriately free on the surface of silica nanoparticles A, improving the release properties of the toner. As a result, when aiming for even higher image quality and higher speed, However, this can further suppress transcriptional omissions.

[0068] The kinematic viscosity of silicone oil at a temperature of 25°C is 30 mm, which controls the molecular mobility originating from the silicone oil. 2 / s or more 500mm 2 Preferably less than / s, and 40mm 2 / s or more 200mm 2 / s or less is more preferable, 70mm 2 / s or more 130mm 2 A value of less than / s is even more preferable. By controlling the kinematic viscosity of the silicone oil at a temperature of 25°C to the above range, the chain length of the silicone oil becomes within an appropriate range, and effective interaction with the cyclic siloxane modifying groups on the surface of the silica fine particles can be obtained. Therefore, it is easier to raise the temperature at which the differential coefficient exceeds 4000. In addition, it becomes easier to control the carbon reduction rate when washing with hexane to a suitable range.

[0069] As a result, even when high discharge energy is applied during the charging process, the silicone oil present on the surface of silica nanoparticles A tends to remain, becoming even less likely to peel off due to the discharge energy, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving charge retention. Furthermore, compounds having a siloxane structure are appropriately free on the surface of silica microparticles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and faster transfer speeds, transfer dropouts can be further suppressed.

[0070] As the silica nanoparticle substrate, which is the silica nanoparticle before surface treatment of silica nanoparticle A, known materials can be used. Examples include silicon compounds, particularly silicon halides, generally silicon chlorides, fumed silica usually produced by burning purified silicon tetrachloride in an oxyhydrogen flame, wet silica produced from water glass, sol-gel silica particles obtained by a wet process, gel silica particles, aqueous colloidal silica particles, alcoholic silica particles, molten silica particles obtained by a gas-phase process, and deflagration silica particles. Fumed silica is preferred.

[0071] The number-average particle size of silica fine particles A is preferably 5 to 40 nm, more preferably 8 to 25 nm, and even more preferably 10 to 17 nm. This allows the silica fine particles A to properly coat the toner particles and to better exhibit the effects of the silica fine particles A. As a result, even when high discharge energy is applied during the charging process, compounds with a siloxane structure present on the surface of silica nanoparticles A tend to remain, becoming even less susceptible to peeling due to the discharge energy, and thus remaining on the surface of the silica nanoparticles, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving charge retention. Furthermore, compounds having a siloxane structure are appropriately free on the surface of silica nanoparticles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and faster transfer speeds, transfer dropouts can be further suppressed.

[0072] The silica fine particles A obtained by the surface treatment method described above can be used in combination with silica fine particles B of a different particle size to obtain even more favorable effects. In other words, it is preferable that the toner further contains silica fine particles B that are different from silica fine particles A. By adding silica nanoparticles B, the surface of silica nanoparticle A can interact appropriately with the surface of silica nanoparticle B. As a result, compounds with a siloxane structure, such as silicone oil, present on the surface of silica nanoparticle A are retained with appropriate strength between the surfaces of silica nanoparticle A and silica nanoparticle B. Therefore, compounds with a siloxane structure present on the surface of silica nanoparticle A are more easily retained.

[0073] The number-average particle size of silica nanoparticles B is preferably 50-500 nm, and 70-300 nm. More preferably, 80-200 nm is preferred. When the number-average particle size of silica fine particles B is within the above range, the dispersibility of silica fine particles B on the toner surface is improved, and the toner can be properly coated.

[0074] Furthermore, it is preferable that the number-average particle size of silica nanoparticles B is 50 nm or more larger than the number-average particle size of silica nanoparticles A, more preferably 70 nm or more larger, and even more preferably 100 nm or more larger. For example, it is preferable that the number-average particle size of silica nanoparticles B is 50 to 200 nm larger than the number-average particle size of silica nanoparticles A, more preferably 70 to 180 nm larger, and even more preferably 100 to 150 nm larger. When the number-average particle diameter ranges of silica nanoparticles A and B are within the above-described relationship, the surface of silica nanoparticle A can interact appropriately with the surface of silica nanoparticle B. As a result, compounds having a siloxane structure, such as silicone oil, present on the surface of silica nanoparticle A are retained between the surfaces of silica nanoparticle A and silica nanoparticle B with appropriate strength.

[0075] Therefore, even when high discharge energy is applied during the charging process, the siloxane-containing compounds present on the surface of silica nanoparticles A tend to remain, becoming even less susceptible to peeling due to the discharge energy, further suppressing material contamination. In addition, the charge state on the toner surface is kept more constant, and the charged state becomes more stable, further improving charge retention. Furthermore, compounds having a siloxane structure are appropriately free on the surface of silica microparticles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and faster transfer speeds, transfer dropouts can be further suppressed.

[0076] <Average particle size by number of silica microparticles> The number-average particle size of silica microparticles can be measured using the Microtrac particle size distribution analyzer HRA(X-100) (manufactured by Nikkiso Co., Ltd.) with a range setting of 0.001 μm to 10 μm. Alternatively, the toner particles can be observed using a scanning electron microscope (SEM) to measure the number and particle size (maximum diameter) of silica microparticles present on the surface of the toner particles, yielding a substantially equivalent number-average particle diameter. In this case, energy-dispersive X-ray spectroscopy (EDS), which is associated with the SEM, can be used to confirm that the measured material is silica microparticles.

[0077] When using silica microparticles A and B in combination, the difference in particle size is usually large. Therefore, it is possible to divide the particles into those larger than a predetermined particle size boundary and those smaller than that boundary, and then calculate the average particle size. The particle size used as the boundary can be determined by measuring the particle size distribution of silica microparticles on the surface of the toner particles and using the particle size at which the frequency falls in a valley (a minimum value sandwiched between maximum values).

[0078] The method for manufacturing toner preferably includes a step of obtaining silica fine particles B. Furthermore, the toner manufacturing method preferably includes a step of preparing silica fine particles B obtained in the following steps. The step of obtaining silica fine particles B is preferably: The process includes the steps of: mixing a silica microparticle substrate with a surface treatment agent containing siloxane bonds; performing a heat treatment at a temperature of 295°C (preferably 300°C) or higher to surface-treat the surface of the silica microparticle substrate with the surface treatment agent containing siloxane bonds to obtain silica microparticles B.

[0079] In other words, it is preferable that the silica nanoparticles B are treated with a surface treatment agent containing siloxane bonds. The method of surface treatment of silica nanoparticles B with a surface treatment agent containing siloxane bonds is the same as the method described above for silica nanoparticles A. When surface treating silica nanoparticles B, the vapor of the surface treatment agent containing siloxane bonds is brought into contact with the silica nanoparticles multiple times (for example, 2 to 1). It is preferable to carry out the process in four separate steps. It is preferable that the silica fine particles B are surface-treated with a cyclic siloxane.

[0080] Examples of silica fine particles B include silicon compounds, particularly silicon halides, generally silicon chlorides, fumed silica usually produced by burning purified silicon tetrachloride in an oxyhydrogen flame, wet silica produced from water glass, sol-gel silica particles obtained by a wet process, gel silica particles, aqueous colloidal silica particles, alcoholic silica particles, molten silica particles obtained by a gas-phase process, and deflagration silica particles. Fumed silica is preferred.

[0081] The silica nanoparticles B are preferably spherical silica nanoparticles. "Spherical" includes shapes that are slightly ellipsoidal or slightly missing, even if they are roughly spherical. The average circularity of the silica nanoparticles B is preferably 0.900 to 1.000, and more preferably 0.930 to 0.990.

[0082] <Measurement of the average circularity of silica microparticles B> Silica nanoparticles B were imaged using a scanning electron microscope (SEM) at a magnification of 25,000x and a pixel resolution of 1280 x 960 (each pixel being approximately 4 nm x 4 nm). The acquired images were then analyzed using the image analysis software ImageJ (available from https: / / imagej.nih.gov / ij / ) to determine their circularity. First, contour extraction is performed on silica nanoparticles B, and their projected area S and perimeter L are measured. Next, the equivalent diameter and circularity are determined using the area S and perimeter L mentioned above. The equivalent diameter is the diameter of a circle with the same area as the projected area of ​​the particle image, and the circularity is defined as the value obtained by dividing the perimeter of the circle obtained from the equivalent diameter by the perimeter of the particle projection image, and is calculated by the following formula. Circularity = 2 × (π × S) 1 / 2 / L The above circularity is calculated for at least 100 silica nanoparticles B, and the arithmetic mean is taken as the average circularity of silica nanoparticles B.

[0083] The toner particles may contain a binder resin. Known binder resins can be used for the toner particles. For example, the following are examples of binder resins: Styrene resins, styrene copolymer resins, polyester resins, polyol resins, polyvinyl chloride resins, phenol resins, naturally modified phenol resins, naturally modified maleic acid resins, acrylic resins, methacrylic resins, polyvinyl acetate, silicone resins, polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumarone indene resins, and petroleum resins. Preferably used resins include styrene copolymer resins, polyester resins, and hybrid resins obtained by mixing polyester resin and styrene copolymer resin or by partial reaction of both. Preferably, polyester resin is used.

[0084] The components that make up polyester resin are described in detail. Note that depending on the type and application, one or more of the following components may be used. Examples of divalent carboxylic acid components constituting polyester resins include the following dicarboxylic acids or their derivatives: benzenedicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride, or their anhydrides or lower alkyl esters; alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or their anhydrides or lower alkyl esters; alkenyl succinic acids or alkyl succinic acids with an average number of carbon atoms of 1 to 50, or their anhydrides or lower alkyl esters; and unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid, or their anhydrides or lower alkyl esters. The alkyl groups in the lower alkyl ester include methyl, ethyl, and propyl groups. Examples include the isopropyl group.

[0085] On the other hand, the following are examples of divalent alcohol components that make up polyester resin. Ethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 1,4-cyclohexanedimethanol (CHDM), hydrogenated bisphenol A, bisphenols represented by formula (I-1) and their derivatives: and diols represented by formula (I-2). [ka]

[0086] In equation (I-1), R is an ethylene group or a propylene group, x and y are integers greater than or equal to 0, and the average value of x + y is between 0 and 10. [ka]

[0087] In equation (I-2), R' is an ethylene group or a propylene group, x' and y' are integers greater than or equal to 0, and the average value of x'+y' is between 0 and 10.

[0088] In addition to the divalent carboxylic acid component and divalent alcohol component described above, the components of the polyester resin may also contain trivalent or higher carboxylic acid components and trivalent or higher alcohol components. There are no particular limitations on the carboxylic acid component with a valency of three or higher, but examples include trimellitic acid, trimellitic anhydride, and pyromellitic acid. Examples of alcohol components with a valency of three or higher include trimethylolpropane, pentaerythritol, and glycerin.

[0089] In addition to the compounds mentioned above, the polyester resin may also contain monovalent carboxylic acid components and monovalent alcohol components. Specifically, examples of monovalent carboxylic acid components include palmitic acid, stearic acid, arachidic acid, behenic acid, cerotic acid, heptacosanoic acid, montanic acid, melissic acid, laxeric acid, tetracontanoic acid, and pentacontanoic acid. Other examples of monohydric alcohol components include behenyl alcohol, ceryl alcohol, melicyl alcohol, and tetracontanol.

[0090] The toner can be used as either a magnetic one-component toner, a non-magnetic one-component toner, or a non-magnetic two-component toner. When used as a magnetic single-component toner, magnetic iron oxide particles are preferably used as the colorant. Examples of magnetic iron oxide particles contained in the magnetic single-component toner include magnetic iron oxides such as magnetite, maghemite, and ferrite, and magnetic iron oxides containing other metal oxides; metals such as Fe, Co, and Ni; or alloys of these metals with metals such as Al, Co, Cu, Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W, and V; and mixtures thereof. The content of magnetic iron oxide particles is determined by the binder resin 10 Preferably, the amount is 30 parts by mass or more and 150 parts by mass or less, per 0 parts by mass.

[0091] Examples of colorants used as non-magnetic one-component toners and non-magnetic toners for two-component developers include the following: As black pigments, carbon blacks such as furnace black, channel black, acetylene black, thermal black, and lamp black are used, as well as magnetic powders such as magnetite and ferrite. Suitable colorants for the yellow color include pigments or dyes. Examples of pigments include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 23, 62, 65, 73, 74, 81, 83, 93, 94, 95, 97, 98, 109, 110, 111, 117, 120, 127, 128, 129, 137, 138, 139, 147, 151, 154, 155, 167, 168, 173, 174, 176, 180, 181, 183, 191, and CI Bat Yellow 1, 3, 20. Examples of dyes include CI Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, and 162. These can be used individually or in combination of two or more.

[0092] Suitable colorants for cyan include pigments or dyes. Examples of pigments include CI Pigment Blue 1, 7, 15, 15;1, 15;2, 15;3, 15;4, 16, 17, 60, 62, 66, etc., CI Bat Blue 6, and CI Acid Blue 45. Examples of dyes include CI Solvent Blue 25, 36, 60, 70, 93, 95, etc. These can be used individually or in combination of two or more. Suitable colorants for magenta include pigments or dyes. Examples of pigments include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48; 2, 48; 3, 48; 4, 49, 50, 51, 52, 53, 54, 55, 57, 57; 1, 58, 60, 63, 64, 68, Examples include 81, 81; 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, etc., as well as CI Pigment Violet 19; CI Bat Red 1, 2, 10, 13, 15, 23, 29, 35. Examples of magenta dyes include oil-soluble dyes such as CI Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122, etc., CI Disperse Red 9, CI Solvent Violet 8, 13, 14, 21, 27, etc., and CI Disperse Violet 1, etc., as well as basic dyes such as CI Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, etc., and CI Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28. These can be used individually or in combination of two or more. The coloring agent content is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the binder resin.

[0093] A release agent (wax) may be used to impart release properties to the toner. Examples of waxes include: aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, olefin copolymers, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxidized forms of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; waxes mainly composed of fatty acid esters such as carnauba wax, behenyl behenate, and montanate ester wax; and waxes in which fatty acid esters have been partially or completely deoxidized, such as deoxidized carnauba wax. These are some examples. Furthermore, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinalic acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, ceryl alcohol, and melissyl alcohol; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; saturated fatty acid bisamides such as methylenebisstearate, ethylenebiscaprate, ethylenebislaurate, and hexamethylenebisstearate; ethylenebisoleamide, hexamethylenebisoleamide, N,N Examples include unsaturated fatty acid amides such as '-dioleyl adipic acid amide and N,N'-dioleyl sebacin acid amide; aromatic bisamides such as m-xylene bisstearamide and N,N'-distearyl isophthalic acid amide; fatty acid metal salts (generally known as metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate; waxes grafted onto aliphatic hydrocarbon waxes with vinyl copolymer monomers such as styrene and acrylic acid; partially esterified fatty acids and polyhydric alcohols such as behenic acid monoglyceride; and methyl ester compounds having hydroxyl groups obtained by hydrogenation of vegetable oils and fats.

[0094] Particularly preferred waxes are aliphatic hydrocarbon waxes. For example, preferred waxes include low molecular weight hydrocarbons obtained by radical polymerization of alkylenes under high pressure or polymerization of Ziegler catalysts or metallocene catalysts under low pressure; Fischer-Tropsch waxes synthesized from coal or natural gas; paraffin waxes; olefin polymers obtained by thermal decomposition of high molecular weight olefin polymers; synthetic hydrocarbon waxes obtained from the distillation residue of hydrocarbons obtained by the Aage process from synthesis gas containing carbon monoxide and hydrogen, or synthetic hydrocarbon waxes obtained by hydrogenation of these.

[0095] Furthermore, it is more preferable to use hydrocarbon waxes that have been separated by methods such as press efflorescence, solvent method, vacuum distillation, or fractional crystallization. In particular, among paraffin waxes, n-paraffin wax and Fischer-Tropsch wax, which mainly consist of linear components, are preferred from the viewpoint of molecular weight distribution. These waxes may be used individually or in combination of two or more types. Preferably, the wax is added in an amount of 1 to 20 parts by mass per 100 parts by mass of the binder resin.

[0096] A charge control agent may be used in the toner. Known charge control agents can be used. Examples include azo iron compounds, azo chromium compounds, azo manganese compounds, azo cobalt compounds, azo zirconium compounds, chromium compounds of carboxylic acid derivatives, zinc compounds of carboxylic acid derivatives, aluminum compounds of carboxylic acid derivatives, and zirconium compounds of carboxylic acid derivatives. The carboxylic acid derivative is preferably an aromatic hydroxycarboxylic acid. A charge-controlling resin can also be used. If necessary, one or more charge-controlling agents may be used in combination. It is preferable to use the charge-controlling agent in an amount of 0.1 parts by mass to 10 parts by mass per 100 parts by mass of the binder resin.

[0097] The toner may be mixed with a magnetic carrier and used as a two-component developer. As the magnetic carrier, ordinary magnetic carriers such as ferrite and magnetite, or resin-coated carriers can be used. Alternatively, magnetic material-dispersed resin particles, in which magnetic material powder is dispersed in the resin component, or porous magnetic core particles containing resin in the voids can be used.

[0098] Magnetic material components used in magnetic material-dispersed resin particles include magnetite particle powder and magnesium. Various magnetic iron compound particle powders can be used, such as mite particle powder, or magnetic iron oxide particle powder containing at least one selected from silicon oxide, silicon hydroxide, aluminum oxide, and aluminum hydroxide; magnetoplanbite-type ferrite particle powder containing barium, strontium, or barium-strontium; and spinel-type ferrite particle powder containing at least one selected from manganese, nickel, zinc, lithium, and magnesium.

[0099] Furthermore, in addition to magnetic components, non-magnetic inorganic compound particle powders such as hematite particle powder, non-magnetic hydrated ferric oxide particle powder, goethite particle powder, titanium oxide particle powder, silica particle powder, talc particle powder, alumina particle powder, barium sulfate particle powder, barium carbonate particle powder, cadmium yellow particle powder, calcium carbonate particle powder, and zinc oxide particle powder may be used in combination with magnetic iron compound particle powder.

[0100] Examples of materials for porous magnetic core particles include magnetite or ferrite. A specific example of ferrite is shown by the following general formula. (M12O) x (M2O) y (Fe2O3) Z In the above equation, M1 is a monovalent metal and M2 is a divalent metal. When x + y + z = 1.0, x and y are 0 ≤ (x, y) ≤ 0.8, and z is 0.2. <z<1.0である) In the formula, it is preferable to use at least one metal atom selected from the group consisting of Li, Fe, Mn, Mg, Sr, Cu, Zn, and Ca as M1 and M2. Other metals that can be used include Ni, Co, Ba, Y, V, Bi, In, Ta, Zr, B, Mo, Na, Sn, Ti, Cr, Al, Si, and rare earth elements.

[0101] The magnetic carrier preferably has magnetic carrier core particles and a resin coating layer on the surface of the magnetic carrier core particles as a resin-coated carrier. The resin coating layer, for example, coats the surface of the magnetic carrier core particles. The magnetic carrier core particles are preferably porous magnetic core particles that contain resin in their voids. Either a thermoplastic resin or a thermosetting resin may be used to fill the voids in the porous magnetic core particles. Examples of thermoplastic resins used for filling include: novolac resin, saturated alkyl polyester resin, polyarylate, polyamide resin, and acrylic resin. Examples of thermosetting resins include phenolic resins, epoxy resins, unsaturated polyester resins, and silicone resins.

[0102] The method for coating the surface of magnetic carrier core particles with resin is not particularly limited, but examples include immersion, spraying, brush application, and application methods such as a fluidized bed. Among these, the immersion method is preferred. The amount of resin coating the surface of the magnetic carrier core particles (amount of resin coating layer) is preferably 0.1 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of magnetic carrier core particles in order to control the ability to impart charge to the toner.

[0103] Examples of resins used in the resin coating layer include acrylic resins such as acrylic acid ester copolymers and methacrylic acid ester copolymers, styrene-acrylic resins such as styrene-acrylic acid ester copolymers and styrene-methacrylic acid ester copolymers, fluorine-containing resins such as polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, monochlorotrifluoroethylene polymer, and polyvinylidene fluoride, silicone resins, polyester resins, polyamide resins, polyvinyl butyral, aminoacrylate resins, iomonomer resins, and polyphenylene sulfide resins. These resins can be used individually or in combination. Preferably, acrylic resins. It is made of resin.

[0104] Among these, a copolymer containing a (meth)acrylic acid ester having an alicyclic hydrocarbon group is particularly preferred from the viewpoint of static charge retention. It is preferable that the resin in the resin coating layer has monomer units of a (meth)acrylic acid ester having an alicyclic hydrocarbon group. That is, the resin in the resin coating layer contains a polymer of monomers including at least a (meth)acrylic acid ester having an alicyclic hydrocarbon group.

[0105] (Meth)acrylic acid esters having an alicyclic hydrocarbon group are preferably, for example, cyclobutyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, cycloheptyl acrylate, dicyclopentenyl acrylate, dicyclopentanyl acrylate, cyclobutyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, dicyclopentenyl methacrylate, and dicyclopentanyl methacrylate. The alicyclic hydrocarbon group is preferably a cycloalkyl group, with 3 to 10 carbon atoms, and more preferably 4 to 8 carbon atoms. One or more of these may be selected and used.

[0106] Furthermore, the content of monomer units of (meth)acrylic acid ester having alicyclic hydrocarbon groups in the copolymer used in the resin coating layer (copolymerization ratio based on the mass of (meth)acrylic acid ester) is preferably 5.0% by mass or more and 80.0% by mass or less, more preferably 50.0% by mass or more and 80.0% by mass or less, and even more preferably 70.0% by mass or more and 80.0% by mass or less. Within the above range, good static charge retention is achieved during long-term use.

[0107] Furthermore, from the viewpoint of charge stability, it is more preferable that the resin in the resin coating layer contains macromonomers as copolymer components in order to improve adhesion between the magnetic carrier core particles and the resin coating layer and to suppress local peeling of the resin coating layer. An example of a specific macromonomer is shown in formula (B). That is, it is preferable that the resin in the resin coating layer has monomer units made up of macromonomers represented by the following formula (B). [ka]

[0108] In formula (B), A represents a polymer of at least one compound selected from the group consisting of methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, styrene, acrylonitrile, and methacrylonitrile. 3 It is either H or CH3. A is preferably a polymer of methyl methacrylate.

[0109] To improve the adhesion between the magnetic carrier core particles and the resin coating layer, the weight-average molecular weight of the macromonomer is preferably 3,000 to 10,000, and more preferably 4,000 to 7,000.

[0110] To improve the adhesion between the magnetic carrier core particles and the resin coating layer, the content of monomer units by macromonomers in the resin used in the resin coating layer is preferably 0.5% by mass or more and 30.0% by mass or less, more preferably 10.0% by mass or more and 30.0% by mass or less, and even more preferably 20.0% by mass or more and 25.0% by mass or less. preferable.

[0111] <Measurement of weight-average molecular weight of macromonomers> The weight-average molecular weight is measured using gel permeation chromatography (GPC) following the procedure below. First, the sample to be measured is prepared as follows. The sample (the coating resin separated from the magnetic carrier and separated using a preparative apparatus) was mixed with tetrahydrofuran (THF) at a concentration of 5 mg / ml and allowed to stand at room temperature for 24 hours to dissolve the sample in THF. The mixture was then passed through a sample processing filter (Myshori Disc H-25-2, manufactured by Tosoh Corporation) to be used as the GPC sample. Next, using a GPC measuring device (HLC-8120GPC, manufactured by Tosoh Corporation), measurements are performed under the following conditions, in accordance with the device's operation manual. (Measurement conditions) Equipment: High-speed GPC "HLC8120 GPC" (manufactured by Tosoh Corporation) Columns: Shodex KF-801, 802, 803, 804, 805, 806, 807 (7 columns, manufactured by Showa Denko) Eluent:THF Flow rate: 1.0ml / min Oven temperature: 40.0℃ Sample injection volume: 0.10 ml

[0112] Furthermore, in calculating the weight-average molecular weight of the sample, the calibration curve used is a molecular weight calibration curve created using standard polystyrene resins (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).

[0113] The toner has toner particles and silica fine particles A on the surface of the toner particles. The toner can be obtained by adding silica fine particles A as an external additive to the toner particles. The content of silica fine particles A in the toner is preferably 0.01 to 10.0 parts by mass, more preferably 0.2 to 3.0 parts by mass, even more preferably 0.4 to 2.0 parts by mass, even more preferably 0.8 to 2.0 parts by mass, and even more preferably 1.0 to 1.7 parts by mass per 100 parts by mass of toner particles.

[0114] This allows the silica microparticles A to more adequately coat the toner particles, enabling the silica microparticles A to exhibit their effects more effectively. As a result, even when aiming for higher image quality and faster transfer speeds, it is possible to obtain a toner that maintains high charge retention over a long period and can more effectively suppress uneven charging due to transfer gaps and material contamination. In addition, compounds having a siloxane structure are appropriately free on the surface of the silica microparticles A, improving the release properties of the toner. As a result, even when aiming for higher image quality and faster transfer speeds, transfer gaps can be further suppressed.

[0115] External additives such as silica microparticles A and silica microparticles B can be added to toner particles by mixing the toner particles and the external additives using a mixer like the one described below. Examples of mixing machines include: Henschel mixer (manufactured by Mitsui Mining Co., Ltd.); Super Mixer (manufactured by Kawata Co., Ltd.); Ribocone (manufactured by Okawara Seisakusho Co., Ltd.); Nauter mixer, Turbulizer, Cyclomix (manufactured by Hosokawa Micron Co., Ltd.); Spiral Pin Mixer (manufactured by Taiheiyo Kiko Co., Ltd.); and Redigge mixer (manufactured by Matsubo Co., Ltd.).

[0116] As described above, the toner contains silica microparticles A, as well as silica fine particles different from silica microparticles A. It is preferable to have subatomic particles B. It is preferable that a portion of the silica fine particles B are embedded on the surface of the toner particles. In the case of silica fine particles B embedded on the surface of the toner particles, the embedding rate of the silica fine particles B in relation to the toner particles is preferably 5 to 50%, more preferably 10 to 25%, and even more preferably 12 to 20%.

[0117] By setting the embedding rate of silica nanoparticles B within the range described above, when silica nanoparticles B are surface-treated, a strong chemical interaction occurs between the polar groups OR at the ends of the siloxane chains on the surface of silica nanoparticles B and the toner particles. This makes it less likely for silica nanoparticles B to detach from the toner particles even when the toner particles are subjected to impact. Furthermore, the strong interaction between silica nanoparticles A and silica nanoparticles B via a siloxane-structured compound, such as silicone oil, present on the surface of silica nanoparticles A suppresses the detachment of silica nanoparticles A from toner particles when the toner particles are subjected to impact. As a result, silica microparticles A can stably exist on the surface of toner particles, thus maintaining a more constant charge state on the toner surface and further improving charge retention. In addition, compounds with a siloxane structure are appropriately free on the surface of silica microparticles A, improving the release properties of the toner. Consequently, even when aiming for higher image quality and faster transfer speeds, transfer dropouts can be further suppressed.

[0118] <Calculation of the embedding rate of silica microparticles B on the surface of toner particles> First, as a pretreatment, silica microparticles that are not embedded or have a low embedding rate are separated from the toner. 20g of a 10% aqueous solution of "Contaminon N" (a pH 7 neutral detergent for cleaning precision measuring instruments consisting of a nonionic surfactant, anionic surfactant, and organic builder) is weighed into a 50mL vial and mixed with 1g of toner. Place the toner in an Iwaki Sangyo Co., Ltd. "KM Shaker" (model: V.SX), set the speed to 50, and shake for 30 seconds. This will cause any unburied silica particles to migrate from the toner particle surface to the aqueous solution.

[0119] Subsequently, in the case of magnetic toner containing magnetic material, the toner particles are restrained using a neodymium magnet, and the silica microparticles that have migrated to the supernatant liquid are separated. The settled toner particles are then dried under vacuum (40°C / 24 hours) to obtain the sample. For non-magnetic toners, a centrifuge (H-9R; manufactured by Kokusan Co., Ltd.) (1000 rpm for 5 minutes) is used to separate the toner particles from the unburied silica microparticles that have migrated to the supernatant liquid. The remaining toner particles are collected as powder by suction filtration and then dried.

[0120] Toner particles are fixed to the sample stage of an electron microscope using carbon tape, and the toner particles are observed under the following conditions: Images are taken from areas where the inclination angle of the toner particle surface is large (for example, 70-110°, preferably around 90°). • Equipment used: Hitachi High-Technologies Corporation SU8220 Acceleration voltage: 2kV Emission current: 10μA Image acquisition: Secondary electron detector Image magnification: 50000x Pixel count: 1280 x 960 (each pixel is approximately 2nm x 2nm)

[0121] The acquired images are analyzed using the image analysis software ImageJ (available from https: / / imagej.nih.gov / ij / ). As shown in Figure 1, silica nanoparticles B are fitted as perfect circles (perfect circles are created using [Oval selections] (the shape is fixed as a perfect circle when operating while holding down the shift key)), and silica fine particles The embedding rate is calculated using the following formula, based on the diameter a of particle B and the length b of the portion where the silica microparticle B is embedded. The length b is measured on a straight line passing through the top of the embedded side in the depth direction and the center of the silica microparticle B, when the silica microparticle B is fitted to a perfect circle. Embedding rate (%) = Length of the portion where silica microparticle B is embedded b / Diameter of silica microparticle B a The above embedding rate is calculated for at least 100 silica microparticles B, and the arithmetic mean is taken as the embedding rate of silica microparticle B. Furthermore, the distinction between silica microparticles B and silica microparticles A on the toner surface can be determined by their particle size.

[0122] The embedding rate of silica microparticles B can be controlled, for example, by adjusting the temperature when mixing toner particles and silica microparticles B in the mixer described above. Alternatively, it can be controlled by performing a surface treatment on the toner particles (embedding treatment of silica microparticles B) after mixing the toner particles and silica microparticles B, and adjusting the conditions (temperature of the treatment atmosphere and exhaust air volume of the treatment space). Heat treatment is preferred for the surface treatment. For example, treatment with hot air can be used. Surface treatment of toner particles can be performed using the following equipment: Hybridization System (manufactured by Nara Machine Works), Novilta (manufactured by Hosokawa Micron Corporation), Mechanofusion System (manufactured by Hosokawa Micron Corporation), Faculty (manufactured by Hosokawa Micron Corporation), Innomizer (manufactured by Hosokawa Micron Corporation), Theta Composer (manufactured by Tokuju Kogyo Co., Ltd.), MechanoMill (manufactured by Okada Seikou Co., Ltd.), and Meteor Rainbow MR Type (manufactured by Nippon Pneumatic Co., Ltd.).

[0123] Furthermore, when silica nanoparticles B and silica nanoparticles A are used in combination, it is preferable to perform the embedding treatment process for silica nanoparticles B in the manner described above, and then add silica nanoparticles A externally. The toner is preferably obtained by the following method. In other words, the toner manufacturing method is Process for obtaining toner particles, A process for preparing silica fine particles A and silica fine particles B, The process involves adding silica fine particles B to the obtained toner particles. A process of heat-treating toner particles to which silica fine particles B have been added externally, and A process of externally adding and mixing silica fine particles A to heat-treated toner particles, It is preferable that it has The content of silica fine particles B is preferably 0.5 parts by mass or more and 10.0 parts by mass or less, more preferably 1.0 parts by mass or more and 8.0 parts by mass or less, and even more preferably 2.0 parts by mass or more and 6.0 parts by mass or less, per 100 parts by mass of toner particles.

[0124] The following provides a specific example of a method for surface-treating toner particles (for example, toner particles to which silica fine particles B have been added) using hot air, with the heat treatment apparatus shown in Figure 2. In this example, toner particles are referred to as the workpiece.

[0125] The material to be processed, supplied in a fixed quantity by the raw material quantitative supply means 1, is guided by compressed gas adjusted by the compressed gas flow rate adjustment means 2 into an introduction pipe 3 installed vertically to the raw material supply means. The material to be processed, having passed through the introduction pipe 3, is uniformly dispersed by a conical projection member 4 located in the center of the raw material supply means, and is guided into eight radially spreading supply pipes 5, which then lead to a processing chamber 6 where heat treatment takes place.

[0126] At this time, the material to be processed supplied to the processing chamber 6 has its flow restricted by a restricting means 9 provided within the processing chamber 6 to regulate the flow of the material to be processed. As a result, the material supplied to the processing chamber 6 is heat-treated while swirling around inside the processing chamber 6, and then cooled. The hot air for heat-treating the supplied material is supplied from the hot air supply means 7, distributed by the distribution member 12, and introduced into the processing chamber 6 in a spiral motion by the swirling member 13 for swirling the hot air. However, it has multiple blades, and the rotation of the hot air can be controlled by adjusting the number and angle of these blades (note that 11 indicates the outlet of the hot air supply means).

[0127] The hot air supplied into the processing chamber 6 preferably has a temperature of 100°C to 300°C at the outlet of the hot air supply means 7, and more preferably 130°C to 190°C. If the temperature at the outlet of the hot air supply means 7 is within the above range, it is possible to prevent fusion or coalescence due to overheating of the workpiece while maintaining a desirable embedding rate of silica fine particles B. The hot air is supplied from the hot air supply means 7. Furthermore, the heat-treated resin particles are cooled by cold air supplied from the cold air supply means 8. The temperature of the cold air supplied from the cold air supply means 8 is preferably between -20°C and 30°C. If the temperature of the cold air is within the above range, the heat-treated workpiece can be cooled efficiently, and fusion or coalescence of the workpiece is less likely to occur. Also, the absolute moisture content of the cold air is 0.5 g / m³. 3 More than 15.0g / m 3 The following is preferable:

[0128] Next, the cooled material to be processed is collected by a collection means 10 located at the lower end of the processing chamber 6. A blower (not shown) is provided at the end of the collection means 10, which is used to suction and transport the material.

[0129] Furthermore, the powder particle supply port 14 is positioned so that the direction of rotation of the supplied material to be processed and the direction of rotation of the hot air are the same, and the recovery means 10 is also positioned tangentially on the outer periphery of the processing chamber 6 to maintain the rotation direction of the rotated material to be processed. In addition, the cold air supplied from the cold air supply means 8 is configured to be supplied horizontally and tangentially from the outer periphery of the device to the circumferential surface of the processing chamber. The swirling direction of the material to be processed supplied from the powder particle supply port 14, the swirling direction of the cold air supplied from the cold air supply means 8, and the swirling direction of the hot air supplied from the hot air supply means 7 are all in the same direction. As a result, turbulence does not occur in the processing chamber, the swirling flow within the apparatus is strengthened, and a strong centrifugal force is applied to the material to be processed before heat treatment, further improving dispersibility, making it easier to obtain toner particles with fewer aggregated particles.

[0130] In the process of obtaining toner particles, the method for producing toner particles is not particularly limited and can be produced by known methods. Examples include grinding, emulsification and agglutination, suspension polymerization, and dissolution and suspension methods.

[0131] Toner particles produced by the pulverization method are manufactured, for example, as follows: The binder resin, colorant, and other additives as needed are thoroughly mixed using a mixer such as a Henschel mixer or ball mill. The mixture is then melt-kneaded using a thermal kneader such as a twin-screw extruder, heated roll, kneader, or extruder. At this stage, wax, magnetic iron oxide particles, and metal-containing compounds may also be added. After the molten mixture is cooled and solidified, it is crushed and classified to obtain toner particles. During this process, the embedding rate of silica microparticles on the surface of the toner particles can be controlled by adjusting the exhaust temperature during fine grinding. The toner particles and external additives such as silica microparticle A are then mixed using a mixer such as a Henschel mixer to obtain the toner.

[0132] Examples of mixing machines include: Henschel mixer (manufactured by Mitsui Mining Co., Ltd.); Super Mixer (manufactured by Kawata Co., Ltd.); Ribocone (manufactured by Okawara Seisakusho Co., Ltd.); Nauter mixer, Turbulizer, Cyclomix (manufactured by Hosokawa Micron Co., Ltd.); Spiral Pin Mixer (manufactured by Taiheiyo Kiko Co., Ltd.); and Redigge mixer (manufactured by Matsubo Co., Ltd.).

[0133] Examples of mixing machines include: KRC kneader (manufactured by Kurimoto Iron Works Co., Ltd.); Buss-Co kneader (manufactured by Buss Co., Ltd.); TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw mixer. Mixing machine (manufactured by Japan Steel Works); PCM mixer (manufactured by Ikegai Iron Works); three-roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho); Nidex (manufactured by Mitsui Mining Co., Ltd.); MS-type pressure kneader, Nidarruder (manufactured by Moriyama Seisakusho); Banbury mixer (manufactured by Kobe Steel, Ltd.).

[0134] Examples of crushing machines include: counter jet mill, micron jet, inomizer (manufactured by Hosokawa Micron Co., Ltd.); IDS type mill, PJM jet crusher (manufactured by Nippon Pneumatic Mfg. Co., Ltd.); cross jet mill (manufactured by Kurimoto Iron Works Co., Ltd.); Ulmax (manufactured by Nisso Engineering Co., Ltd.); SK Jet-O-Mill (manufactured by Seishin Enterprise Co., Ltd.); Cryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Turbo Mill (manufactured by Turbo Industries Co., Ltd.); and Super Rotor (manufactured by Nisshin Engineering Co., Ltd.).

[0135] Furthermore, if necessary, after grinding, the surface treatment of the toner particles can be performed using a hybridization system (manufactured by Nara Machine Works), Nobilta (manufactured by Hosokawa Micron Corporation), Mechanofusion system (manufactured by Hosokawa Micron Corporation), Faculty (manufactured by Hosokawa Micron Corporation), Inomizer (manufactured by Hosokawa Micron Corporation), Theta Composer (manufactured by Tokuju Kogyo Co., Ltd.), Mechanomill (manufactured by Okada Seikou Co., Ltd.), or Meteor Rainbow MR Type (manufactured by Nippon Pneumatic Co., Ltd.) to control the embedding rate of silica microparticles on the surface of the toner particles.

[0136] Examples of classifiers include: Classil, Micron Classifier, Spedick Classifier (manufactured by Seishin Corporation); Turbo Classifier (manufactured by Nisshin Engineering Co., Ltd.); Micron Separator, Turboplex (ATP), TSP Separator (manufactured by Hosokawa Micron Corporation); Elbow Jet (manufactured by Nippon Steel Mining Co., Ltd.), Dispersion Separator (manufactured by Nippon Pneumatic Mfg. Co., Ltd.); and YM Microcut (manufactured by Yaskawa Trading Co., Ltd.).

[0137] Examples of sieving devices used to separate coarse particles include: Ultrasonic (manufactured by Koei Sangyo Co., Ltd.); Resona Sieve, Gyro Shifter (manufactured by 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.); Micro Shifter (manufactured by Makino Sangyo Co., Ltd.); and circular vibrating screen.

[0138] Toner particles are manufactured by emulsification and agglutination, for example, as shown below. <Process for preparing a resin fine particle dispersion (preparation process)> For example, the binder resin component is dissolved in an organic solvent to form a homogeneous solution. Then, basic compounds or surfactants are added as needed. An aqueous medium is slowly added to this solution while applying shear force using a homogenizer or the like to form resin microparticles of the binder resin. Finally, the organic solvent is removed to prepare a resin microparticle dispersion in which the resin microparticles are dispersed.

[0139] When preparing a resin fine particle dispersion, the amount of resin component to be dissolved in the organic solvent is preferably 10 parts by mass or more and 50 parts by mass or less, and more preferably 30 parts by mass or more and 50 parts by mass or less, per 100 parts by mass of the organic solvent.

[0140] Any organic solvent capable of dissolving the resin components can be used, but solvents with high solubility for olefin resins, such as toluene, xylene, and ethyl acetate, are preferred.

[0141] The surfactant is not particularly limited. Examples include anionic surfactants such as sulfate esters, sulfonates, carboxylates, phosphates, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, and polyhydric alcohols. ru.

[0142] Examples of basic compounds include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as triethylamine, trimethylamine, dimethylaminoethanol, and diethylaminoethanol. These basic compounds may be used individually or in combination of two or more.

[0143] <Agglomeration process> The aggregation process involves, for example, mixing the resin microparticle dispersion with a coloring agent microparticle dispersion, a wax microparticle dispersion, and a silicone oil emulsion as needed to prepare a mixture, and then agglomerating the microparticles contained in the prepared mixture to form aggregate particles.

[0144] Suitable methods for forming the aggregate particles include adding and mixing a flocculant into the above-mentioned mixed liquid, and then raising the temperature or applying mechanical power as appropriate.

[0145] A dispersion of colorant microparticles is prepared by dispersing the colorant described above. The colorant microparticles are dispersed by known methods, but media-type dispersers such as rotary shear homogenizers, ball mills, sand mills, and attritors, and high-pressure opposing impact dispersers are preferably used. In addition, surfactants or polymer dispersants that impart dispersion stability can be added as needed.

[0146] Wax particulate dispersions and silicone oil emulsions are prepared by dispersing each material in an aqueous medium. Each material is dispersed by known methods, but media-type dispersers such as rotary shear homogenizers, ball mills, sand mills, and attritors, and high-pressure opposing impact dispersers are preferably used. In addition, surfactants or polymer dispersants that impart dispersion stability can be added as needed.

[0147] Examples of flocculants include monovalent metal salts such as sodium and potassium; divalent metal salts such as calcium and magnesium; trivalent metal salts such as iron and aluminum; and polyvalent metal salts such as polyaluminum chloride. From the viewpoint of particle size controllability in the flocculation process, divalent metal salts such as calcium chloride and magnesium sulfate are preferred. The addition and mixing of the flocculant is preferably carried out within a temperature range of room temperature to 75°C. Under these temperature conditions, the flocculation proceeds in a stable manner. The mixing can be carried out using known mixing devices, homogenizers, mixers, etc.

[0148] <Fusion process> The fusion process involves heating the aggregate particles to a temperature preferably above the melting point of the olefin resin and fusing them together to produce particles with a smooth surface. Before proceeding to the fusion process, chelating agents, pH adjusters, surfactants, etc., can be added as appropriate to prevent fusion between the resulting resin particles.

[0149] Examples of chelating agents include alkali metal salts such as ethylenediaminetetraacetic acid (EDTA) and its sodium salt, sodium gluconate, sodium tartrate, potassium citrate and sodium citrate, nitrilotriacetate (NTA) salts, and many water-soluble polymers (polyelectrolytes) that contain both COOH and OH functionalities. The time required for the fusion process varies depending on the heating temperature; a shorter time is sufficient at higher temperatures, while a longer time is needed at lower temperatures. In other words, the heating and fusion time cannot be precisely defined as it depends on the heating temperature, but it is generally between 10 minutes and 10 hours.

[0150] <Cooling process> This step involves cooling the temperature of the aqueous medium containing the resin particles obtained in the fusion process. While not particularly limited, the specific cooling rate is approximately 0.1 to 50°C / minute.

[0151] <Washing Process> The resin particles produced through the above process can be cleaned and filtered repeatedly to remove impurities from them. Specifically, it is preferable to wash the resin particles with an aqueous solution containing a chelating agent such as ethylenediaminetetraacetic acid (EDTA) and its sodium salt, and then wash them further with pure water. By repeatedly washing and filtering with pure water, metal salts and surfactants in the resin particles can be removed. From the viewpoint of manufacturing efficiency, 3 to 20 filtrations are preferable, and 3 to 10 filtrations are more preferable.

[0152] <Drying and classification process> Toner particles can be obtained by drying the washed resin particles and classifying them as appropriate.

[0153] Toner particles produced by the dissolution-suspension method are manufactured, for example, as follows: In the dissolution suspension method, a resin composition obtained by dissolving a binder resin component in an organic solvent is dispersed in an aqueous medium to granulate particles of the resin composition, and then the organic solvent contained in the particles of the resin composition is removed to produce toner particles. This dissolution and suspension method is applicable to any resin component that dissolves in an organic solvent, and it also allows for easy shape control depending on the conditions during solvent removal. The following describes, but is not limited to, a toner manufacturing method using the dissolution suspension method.

[0154] <Resin component dissolution process> In the resin component dissolution step, the binder resin, and optionally other components such as colorants, waxes, and silicone oils, are dissolved or dispersed in an organic solvent to prepare the resin composition. Any organic solvent capable of dissolving the resin components can be used. Specifically, examples include toluene, xylene, chloroform, methylene chloride, and ethyl acetate. However, toluene and ethyl acetate are preferred due to their ability to promote crystallization of crystalline resins and their ease of solvent removal.

[0155] There are no restrictions on the amount of organic solvent used, but it should be an amount that allows the resin composition to disperse in a poor medium such as water and achieve a viscosity that enables granulation. Specifically, a mass ratio of the resin component, and optionally other components such as colorants, waxes, and silicone oils, to the organic solvent of 10 / 90 to 50 / 50 is preferred from the viewpoint of granulation properties and toner particle production efficiency, as described later.

[0156] On the other hand, the colorants, waxes, and silicone oils do not need to be dissolved in organic solvents; they may be dispersed. When using the colorants, waxes, and silicone oils in a dispersed state, it is preferable to disperse them using a disperser such as a bead mill.

[0157] <Granulation process> The granulation process is a step in which the obtained resin composition is dispersed in an aqueous medium using a dispersant to obtain a predetermined toner particle size, thereby preparing particles of the resin composition. Water is the primary water-based medium used. Furthermore, it is preferable that the aqueous medium contains 1% to 30% by mass of a monovalent metal salt. The presence of a monovalent metal salt suppresses the diffusion of organic solvents in the resin composition into the aqueous medium, thereby increasing the crystallinity of the resin components contained in the resulting toner particles. As a result, the toner tends to have good blocking resistance and a good particle size distribution.

[0158] Examples of monovalent metal salts include sodium chloride, potassium chloride, lithium chloride, and potassium bromide, of which sodium chloride and potassium chloride are preferred. Furthermore, the mixing ratio (mass ratio) of the aqueous medium and the resin composition is preferably aqueous medium / resin composition = 90 / 10 to 50 / 50.

[0159] The above-mentioned dispersant is not particularly limited, but as an organic dispersant, cationic, anionic, and nonionic surfactants can be used, with anionic surfactants being preferred. Examples include sodium alkylbenzene sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfonate, and sodium alkyl diphenyl ether disulfonate. On the other hand, examples of inorganic dispersants include tricalcium phosphate, hydroxyapatite, calcium carbonate microparticles, titanium dioxide microparticles, and silica microparticles.

[0160] Of these, the inorganic dispersant tricalcium phosphate is preferred. This is because it has very little adverse effect on granulation properties, stability, and the characteristics of the resulting toner. The amount of dispersant added is determined according to the particle size of the granules; as the amount of dispersant added increases, the particle size decreases. For this reason, although the amount of dispersant added varies depending on the desired particle size, it is preferable to use it in the range of 0.1 to 15% by mass relative to the resin composition. Furthermore, when preparing resin composition particles in an aqueous medium, it is preferable to do so under high-speed shearing. Examples of devices that provide high-speed shearing include various high-speed dispersers and ultrasonic dispersers.

[0161] <Solvent removal process> In the solvent removal process, the organic solvent contained in the particles of the obtained resin composition is removed to produce toner particles. The removal of the organic solvent is preferably carried out while stirring.

[0162] <Washing, drying, and classification process> After the solvent removal step, a washing and drying step may be performed in which the toner particles are washed multiple times with water or the like, filtered, and dried. Furthermore, if a dispersant that dissolves under acidic conditions, such as tricalcium phosphate, is used, it is preferable to wash with hydrochloric acid followed by washing with water. Washing removes the dispersant used for granulation. After washing, toner particles can be obtained by filtering and drying, and then appropriately classifying the material.

[0163] Toner particles are manufactured by suspension polymerization, for example, as shown below. A polymerizable monomer composition is prepared by uniformly dissolving or dispersing polymerizable monomers that generate a binder resin, colorants, wax components, and polymerization initiators using a disperser such as a homogenizer, ball mill, or ultrasonic disperser. After granulating the polymerizable monomer composition particles by dispersing the polymerizable monomer composition in an aqueous medium, toner particles are obtained by polymerizing the polymerizable monomers in the particles made of the polymerizable monomer composition.

[0164] In this case, it is preferable that the polymerizable monomer composition is prepared by mixing a dispersion in which a colorant is dispersed in a first polymerizable monomer (or a portion of the polymerizable monomers) with at least a second polymerizable monomer (or the remaining polymerizable monomers). That is, by thoroughly dispersing the colorant in the first polymerizable monomer and then mixing it with the second polymerizable monomer together with other toner materials, the colorant can be present in the polymerized particles in a better dispersed state.

[0165] The obtained toner particles are filtered, washed, dried, and classified by known methods as necessary. That's good too.

[0166] <Process for adding external additives to toner particles> Toner particles and external additives (silica microparticles A and, if necessary, silica microparticles B) can be mixed using a mixer such as a Henschel mixer to obtain toner.

[0167] When using silica microparticles A and silica microparticles B together, silica microparticles A and B may be added to the toner particles at the same time. However, as described above, it is preferable to add silica microparticles B and silica microparticles A separately. In the step of externally adding silica fine particles B to the obtained toner particles, the silica fine particles B can be mixed with the toner particles using a mixer such as a Henschel mixer. Next, in the step of heat-treating the toner particles to which silica fine particles B have been added, it is preferable to use the aforementioned heat treatment apparatus to heat-treat the toner particles to which silica fine particles B have been added as the workpiece. Then, in the step of externally adding silica fine particles A to the heat-treated toner particles, the silica fine particles A are mixed with the heat-treated toner particles using a mixer such as a Henschel mixer to obtain toner. [Examples]

[0168] The basic structure and features of the present invention have been described above. The present invention will now be described in detail based on examples. However, the present invention is not limited thereto. Unless otherwise specified, parts and percentages are based on mass.

[0169] <Example of manufacturing of binder resin 1> • Bisphenol A ethylene oxide (2.2 molar adduct): 50.0 molar parts • Bisphenol A propylene oxide (2.2 molar adduct): 50.0 molar parts Terephthalic acid: 90.0 molar parts • Trimellitus anhydride: 10.0 moles 100 parts by mass of the monomer constituting the above polyester unit was mixed with 500 ppm of titanium tetrabutoxide in a 5-liter autoclave. A reflux condenser, moisture separator, N2 gas introduction tube, thermometer, and stirring device were attached to the autoclave, and a condensation polymerization reaction was carried out at 230°C while introducing N2 gas into the autoclave. The reaction time was adjusted to achieve the desired softening point, and after the reaction was completed, the material was removed from the container, cooled, and pulverized to obtain binder resin 1. The softening point of binder resin 1 was 130°C, and the Tg was 57°C. The softening point was measured as follows:

[0170] (Measurement of softening point) The softening point is measured using a constant-load extrusion type capillary rheometer, the "Flow Characteristics Evaluation Device Flow Tester CFT-500D" (manufactured by Shimadzu Corporation), according to the manual included with the device. With this device, a constant load is applied from the top of the sample by a piston, the sample filled in the cylinder is heated and melted, and the molten sample is extruded from a die at the bottom of the cylinder. A flow curve showing the relationship between the piston descent amount and temperature can be obtained. The softening point will be the "melting temperature using the 1 / 2 method" as described in the manual included with the "Flow Characteristics Evaluation Device Flow Tester CFT-500D". The melting temperature using the 1 / 2 method is calculated as follows:

[0171] First, calculate half the difference between the piston's descent Smax at the end of the outflow and the piston's descent Smin at the start of the outflow (let's call this X. X = (Smax - Smin) / 2). Then, in the flow curve, the piston's descent is X and Smin. The temperature of the flow curve when it equals the sum of the two values ​​is the melting temperature in the 1 / 2 method. The sample used for measurement is approximately 1.3 g of sample, compressed at 10 MPa for 60 seconds at 25°C using a tablet molding compressor (e.g., NT-100H, manufactured by NPA Systems Co., Ltd.) to form a cylindrical shape with a diameter of approximately 8 mm. The measurement conditions for CFT-500D are as follows: Test mode: Temperature increase method Starting temperature: 50℃ Achieved temperature: 200℃ Measurement interval: 1.0℃ Heating rate: 4.0℃ / min Piston cross-sectional area: 1,000 cm² 2 Test load (piston load): 10.0 kgf / cm 2 (0.9807 MPa) Preheating time: 300 seconds Die hole diameter: 1.0mm Die length: 1.0mm

[0172] <Example of manufacturing silica microparticle A1> BET specific surface area 145m 2 500 g of fumed silica (silica microparticle substrate) at a concentration of / g was placed in a reaction vessel and heated under nitrogen purging and stirring, with the temperature inside the reaction vessel controlled to 330°C. Next, as a surface treatment agent, octamethylcyclotetrasiloxane was supplied into the reaction vessel in vapor form at a rate of 10 g / min for 60 minutes, followed by heating and stirring for 180 minutes to surface treat the silica microparticle substrate. After removing the unreacted surface treatment agent, polydimethylsiloxane (kinematic viscosity at 25°C: 100 mm) was added under stirring with nitrogen purging. 2A solution prepared by diluting 50 g of silica ( / s) with 500 g of hexane was sprayed onto the surface, and then heated and stirred for 120 minutes to obtain silica nanoparticles A1. Table 1 shows the treatment conditions for the first stage, and Table 2 shows the treatment conditions for the second stage and the physical properties of silica nanoparticles A1.

[0173] <Manufacturing examples of silica microparticles A2-A18> As shown in Tables 1 and 2, silica nanoparticles A2 to A18 were obtained by manufacturing them in the same manner as silica nanoparticle A1, except that the fumed silica (silica nanoparticle substrate), surface treatment agent, and treatment conditions were changed. The physical properties of silica nanoparticles A2 to A18 are shown in Table 2. [Table 1] In Tables 1 and 2, the amount of treatment agent (parts) indicates the number of parts by mass of the surface treatment agent per 100 parts by mass of silica fine particle substrate.

[0174] [Table 2] In the table, particle size represents the number-average particle size.

[0175] <Example of manufacturing silica microparticles B1> 500g of fumed silica (silica microparticle substrate) with an average particle size of 120nm was placed in a stainless steel (SUS304) reaction vessel connected to a vacuum pump. The pressure inside the reaction vessel was reduced to 0.001Pa, and the mixture was heated and stirred to control the temperature of the reaction vessel to 330°C. After a 30-minute degassing treatment in this state, octamethylcyclotetrasiloxane vapor was introduced as a surface treatment agent, supplied at a rate of 6 g / min, while the valve opening between the vacuum pump and the reaction vessel was adjusted to control the pressure inside the reaction vessel to 1 Pa. In this state, the silica nanoparticle substrate was surface-treated by heating and stirring for 20 minutes. The total amount of octamethylcyclotetrasiloxane introduced in this process was 120 g. Subsequently, the reaction vessel was evacuated under reduced pressure to 0.001 Pa to remove the reaction products and unreacted surface treatment agent. After 30 minutes of degassing in this state, octamethylcyclotetrasiloxane vapor was again introduced as the surface treatment agent, supplied at a rate of 6 g / min while controlling the pressure in the reaction vessel to 1 Pa. In this state, the silica nanoparticles were subjected to a second surface treatment by heating and stirring for 20 minutes. The total amount of octamethylcyclotetrasiloxane introduced in this process was 120 g. After a 30-minute degassing treatment in this state, octamethylcyclotetrasiloxane vapor was introduced again as a surface treatment agent, supplied at a rate of 6 g / min, while controlling the pressure inside the reaction vessel to 1 Pa. In this state, the silica nanoparticles underwent a third surface treatment by heating and stirring for 20 minutes. The total amount of octamethylcyclotetrasiloxane introduced in this process was 120 g. Subsequently, while continuing to heat and stir, the reaction vessel was evacuated under reduced pressure to 0.001 Pa to remove unreacted surface treatment agent, yielding silica nanoparticles B1. The average circularity of silica nanoparticles B1 was 0.945.

[0176] <Manufacturing examples of silica microparticles B2 and B3> As shown in Table 3, silica nanoparticles B2 and B3 were obtained by manufacturing them in the same manner as silica nanoparticles B1, except that the number-average particle size of the fumed silica (silica nanoparticle substrate) was changed. The physical properties of silica nanoparticles B2 and B3 are shown in Table 3. [Table 3]

[0177] <Example 1> <Example of Toner 1 manufacturing> • Binding resin 1,100 units • Paraffin wax (melting point 78°C) 4 parts • Nipex35 (Carbon Black) 6-piece set The above materials were preliminarily mixed using a Henschel mixer (product name: FM-10C type, manufactured by Nippon Coke Co., Ltd.), and then melt-kneaded at 160 °C using a twin-screw kneading extruder. The obtained kneaded product was cooled, coarsely pulverized using a hammer mill, and then finely pulverized using a turbo mill. The obtained finely pulverized product was classified using a multi-stage classifier utilizing the Coandă effect to obtain toner particles 1 having a weight average particle diameter (D4) of 6.5 μm.

[0178] Next, the obtained toner particles 1 were externally added with silica fine particles B1 as the first external addition treatment as follows. · Toner particles 1: 100 parts · Silica fine particles B1: 4.0 parts The above materials were mixed using a Henschel mixer. The operating conditions of the Henschel mixer were a rotation speed of 4000 rpm, a rotation time of 2 min, and a heating temperature of room temperature. Thereafter, heat treatment was performed using the surface heat treatment apparatus shown in Fig. 2 to embed a part of the silica fine particles B1 on the surface of the toner particles. The operating conditions of the surface heat treatment apparatus were a feed rate = 1.0 kg / hr, a hot air temperature = 180 °C, a hot air flow rate = 1.4 m 3 / min., a cold air temperature = 3 °C, and a cold air flow rate = 1.2 m 3 / min.

[0179] Next, fine powder and coarse powder were simultaneously classified and removed using a pneumatic classifier utilizing the Coandă effect (「Elbow Jet Lab EJ-L3」, manufactured by Nippon Steel Mining Co., Ltd.) to obtain toner particles 1 in which silica fine particles B1 were embedded on the surface. The heat-treated toner particles 1 thus obtained were externally added with silica fine particles A1 as the second external addition treatment as follows. · Toner particles 1 with silica fine particles B1 embedded on the surface: 100 parts · Silica fine particles A1: 1.6 parts

[0180] The above materials were used with a Henschel mixer (product name: FM-10C type, manufactured by Nippon Coke Co., Ltd.) at a rotation speed of 67 s -1After mixing at room temperature with a rotation time of 2 minutes at 4000 rpm, the mixture was passed through an ultrasonic vibrating sieve with a mesh size of 54 μm to obtain toner 1. The embedding rate of silica fine particles B1 in the obtained toner 1 is shown in Table 4.

[0181] <Example of manufacturing magnetic carrier core particle 1> Process 1 (Weighing and Mixing Process) Fe2O368.3% by mass MnCO328.5% by mass Mg(OH)22.0% by mass SrCO31.2% by mass The above ferrite raw materials were weighed, and 20 parts water was added to 80 parts ferrite raw materials. Then, a slurry was prepared by wet mixing for 3 hours using a zirconia ball mill with a diameter (φ) of 10 mm. The solid content concentration of the slurry was 80% by mass.

[0182] Step 2 (Calibration Process) After drying the mixed slurry using a spray dryer (manufactured by Okawara Chemical Machinery Co., Ltd.), calcined ferrite was produced by firing it in a batch-type electric furnace under a nitrogen atmosphere (oxygen concentration 1.0 vol%) at a temperature of 1050°C for 3.0 hours.

[0183] Step 3 (Grinding Process) Calcined ferrite was crushed to approximately 0.5 mm using a crusher, and then water was added to prepare a slurry. The solid content concentration of the slurry was set to 70% by mass. This slurry was then ground for 3 hours in a wet ball mill using 1 / 8-inch stainless steel beads to obtain a slurry. This slurry was further ground for 4 hours in a wet bead mill using 1 mm diameter zirconia to obtain a calcined ferrite slurry with a volume-based 50% particle size (D50) of 1.3 μm.

[0184] Process 4 (granulation process) To 100 parts of the above calcined ferrite slurry, 1.0 part of ammonium polycarboxylate was added as a dispersant and 1.5 parts of polyvinyl alcohol was added as a binder. The mixture was then granulated into spherical particles using a spray dryer (manufactured by Okawara Chemical Machinery Co., Ltd.) and dried. After adjusting the particle size of the resulting granules, the mixture was heated in a rotary electric furnace at 700°C for 2 hours to remove organic matter such as dispersants and binders.

[0185] Step 5 (Baking process) Under a nitrogen atmosphere (oxygen concentration 1.0 vol%), from room temperature to firing temperature (1100°C) The process involved heating for 2 hours, maintaining a temperature of 1100°C for 4 hours to calcine the granules. Subsequently, the temperature was lowered to 60°C over 8 hours, the atmosphere was changed from nitrogen to air, and the calcined material was removed at a temperature of 40°C or lower.

[0186] Process 6 (Sorting Process) After crushing the aggregated particles in the resulting calcined material, coarse particles were removed by sieving with a 150 μm mesh sieve, fine powder was removed by air classification, and low magnetic force components were further removed by magnetic separation to obtain porous magnetic core particles.

[0187] Process 7 (filling process) 100 parts of porous magnetic core particles 1 were placed in the stirring container of a mixing and stirring machine (Dalton NDMV type universal stirring machine), and 5 parts of a filling resin consisting of methyl silicone oligomer: 95.0% by mass and γ-aminopropyltrimethoxysilane: 5.0% by mass were added dropwise at atmospheric pressure while maintaining a temperature of 60°C.

[0188] After the dropping was complete, stirring was continued while adjusting the time, and the temperature was raised to 70°C to fill the particles of each porous magnetic core with the resin composition. The resin-filled magnetic core particles obtained after cooling were transferred to a mixer with spiral blades (UD-AT drum mixer manufactured by Sugiyama Heavy Industries Co., Ltd.) in a rotatable mixing container, and the temperature was raised to 140°C at a heating rate of 2°C / min under a nitrogen atmosphere while stirring. Heating and stirring were then continued at 140°C for 50 minutes. The ferrite particles were then cooled to room temperature, filled with resin, and hardened. Non-magnetic materials were removed using a magnetic separator. Coarse particles were then removed using a vibrating screen to obtain resin-filled magnetic carrier core particles 1.

[0189] (Examples of coating resin manufacturing) • Cyclohexyl methacrylate monomer 26.8% by mass • Methyl methacrylate monomer 0.2% by mass • Methyl methacrylate macromonomer 8.4% by mass (a macromonomer with a weight-average molecular weight of 5000 and a methacryloyl group at one end) (Represented by formula (B), where A is a polymer of methyl methacrylate.) • Toluene 31.3% by mass • Methyl ethyl ketone 31.3% by mass • Azobisisobutyronitrile 2.0% by mass Of the above materials, cyclohexyl methacrylate monomer, methyl methacrylate monomer, methyl methacrylate macromonomer, toluene, and methyl ethyl ketone were placed in a four-necked separable flask equipped with a reflux condenser, thermometer, nitrogen inlet tube, and stirrer. After introducing nitrogen gas into the separable flask to create a sufficient nitrogen atmosphere, the mixture was heated to 80°C, azobisisobutyronitrile was added, and polymerization was carried out under reflux for 5 hours. Hexane was injected into the resulting reactant to precipitate the copolymer. The resulting precipitate was filtered off and then vacuum-dried to obtain the resin. Thirty parts of the resin were dissolved in a mixed solvent of 40 parts toluene and 30 parts methyl ethyl ketone to obtain a resin solution (solid content concentration 30%).

[0190] (Preparation of coating resin solution) • Resin solution (solid content concentration 30%) 33.3% by mass • Toluene 66.4% by mass • Carbon black (Regal 330; manufactured by Cabot) 0.3% by mass (number average particle size of primary particles: 25 nm, nitrogen adsorption specific surface area: 94 m²) 2 / g, DBP oil absorption: 75ml / 100g) The above material was put into a paint shaker and dispersed for 1 hour using zirconia beads with a diameter of 0.5 mm. The obtained dispersion was filtered through a 5.0 μm membrane filter to obtain a coating resin solution.

[0191] <Production Example of Magnetic Carrier 1> The coating resin solution and magnetic carrier core particles were put into a vacuum degassing kneader maintained at room temperature (the input amount of the coating resin solution was 2.5 parts as the resin component with respect to 100 parts of magnetic carrier core particles 1). After the input, it was stirred at a rotation speed of 30 rpm for 15 minutes. After the solvent volatilized to a certain level (80% or more), the temperature was raised to 80 °C while mixing under reduced pressure, and toluene was distilled off over 2 hours and then cooled. The obtained magnetic carrier was separated for low magnetic products by magnetic separation, passed through a sieve with an aperture of 70 μm, and then classified by an air classifier to obtain magnetic carrier 1 with a 50% particle size (D50) of 38.2 μm based on volume distribution.

[0192] <Preparation and Evaluation of Two-Component Developer 1> Toner 1 and magnetic carrier 1 were added so that the toner concentration became 8.0 mass%, and using a V-type mixer (V-10 type: manufactured by Tokuju Seisakusho Co., Ltd.), -1 they were mixed under the conditions of 0.5 s and a rotation time of 5 min to prepare two-component developer 1. The following evaluations were performed using the obtained two-component developer 1.

[0193] <Evaluation> As an image forming apparatus, imagePRESS C850 (manufactured by Canon) was used. The fixing unit was taken out externally so that the fixing temperature could be arbitrarily controlled, and it was modified so that an image forming speed of 105 sheets / min in A4 size could be achieved. Also, the development contrast was made adjustable to an arbitrary value, and the automatic correction by the main body was made inoperative. Also, the frequency of the alternating electric field was fixed at 2.0 kHz, and the voltage between peaks (Vpp) was made changeable in steps of 0.1 kV from 0.7 kV to 1.8 kV.

[0194] Two-component developer 1 was placed in the cyan position of the image forming apparatus, the charging voltage VD of the electrostatic latent image carrier and the laser power were adjusted, and the evaluation described below was performed. For each evaluation, two levels of image forming speed were performed: 105 A4 size images per minute and 85 A4 size images per minute. The evaluation paper used is white paper (product name: CS-814 (A4, 81.4 g / m²)). 2 (Used by Canon Marketing Japan Inc.)

[0195] <Evaluation of static charge retention> Electrostatic retention was evaluated based on the developability before and after continuous printing. Under normal temperature and humidity conditions (temperature 25°C, relative humidity 50%), the initial Vpp was fixed at 1.3kV, and the contrast potential was set so that the reflectance density of a solid black image was 1.50. With this setting, 100,000 image patterns with a 5% ratio of solid black image to the paper surface were output consecutively. Then, with Vpp set to 1.3kV, a solid black image was output again, and the reflectance density was measured. The contrast potential at which the reflectance density of the solid black image was 1.50 was determined, and the difference between the initial and post-output values ​​was compared. The reflectance density was measured using a 500 series spectrophotometer (manufactured by X-Rite). Criteria for evaluating developability: The worse the charge retention, the greater the difference between the initial state and the state after output. A: The difference between the initial voltage and the output voltage is less than 40V. B: The difference between the initial voltage and the output voltage is between 40V and 50V. C: The difference between the initial voltage and the output voltage is between 50V and 60V. D: The difference between the initial voltage and the output voltage is between 60V and 70V. E: The difference between the initial voltage and the output voltage is between 70V and 80V. F: The difference between the initial voltage and the output voltage is between 80V and 90V. G: The difference between the initial voltage and the output voltage is between 90V and 100V. H: The difference between the initial voltage and the output voltage is 100V or more.

[0196] <Evaluation of transcription omissions> Under normal temperature and humidity conditions (temperature 25°C, relative humidity 50%), the toner application rate for FFh images was 0.45 mg / cm². 2 The development voltage was initially adjusted to achieve the following. FFh is a value representing 256 gradations in hexadecimal, where 00h is the 1st gradation (white area) and FFh is the 256th gradation (solid area).

[0197] 200 solid images with 100% print coverage were printed consecutively to simulate the state immediately after fresh toner was supplied from the toner bottle / hopper to the developing unit. Then, one 500μm horizontal line pattern was printed. The fine lines were magnified using a digital microscope to acquire the image, and then binarized. The amount of gaps within the line width was calculated as the gap rate based on the area ratio. For example, a 50% gap rate means that 50% of the white background is visible within the line width. Transfer gaps were evaluated according to the following criteria. A: Dropout rate less than 1.0% B: Dropout rate between 1.0% and 4.0% C: Dropout rate between 4.0% and 8.0% D: Dropout rate between 8.0% and 12.0% E: Dropout rate between 12.0% and 16.0% F: Dropout rate between 16.0% and 20.0% G: Dropout rate of 20.0% or more

[0198] <Evaluation of uneven electrostatic charge due to material contamination> Uneven charging due to component contamination was evaluated by the in-plane uniformity of the image after continuous printing and the presence of static charge on the wires. Immediately after conducting a durability test of 200,000 charts with FFH output and an image ratio of 5% under normal temperature and humidity conditions (temperature 25°C, relative humidity 50%), 10 charts with FFH output and an image ratio of 40% were printed. Subsequently, one 99H output chart (full A4 halftone image) with an image ratio of 100% was printed.

[0199] Image in-plane uniformity was determined by measuring image density using a 500 series spectrophotometer (manufactured by X-Rite). The measurement site is, Three points: 0.5 cm from the leading edge of the image (the side printed first), and 5.0 cm, 15.0 cm, and 25.0 cm from the left edge of the image (with the side printed first being the top); Three points located 7.0 cm from the front edge of the image, and 5.0 cm, 15.0 cm, and 25.0 cm from the left edge of the image; Three points located 14.0 cm from the front edge of the image, and 5.0 cm, 15.0 cm, and 25.0 cm from the left edge of the image; Twelve points were selected: 20.0 cm from the leading edge of the image, and three points at 5.0 cm, 15.0 cm, and 25.0 cm from the left edge of the image. The difference between the highest and lowest image density was calculated for each of the 12 points. The image with the largest density difference among the 50 images was used as the evaluation result. The in-plane uniformity of the obtained images was judged according to the following criteria. The results are shown in Table 6. A: Concentration difference less than 0.020 B: Concentration difference between 0.020 and less than 0.030 C: Concentration difference between 0.030 and less than 0.040 D: Concentration difference between 0.040 and less than 0.050 E: Concentration difference between 0.050 and less than 0.060 F: Concentration difference between 0.060 and less than 0.080 G: Concentration difference 0.080 or more The evaluation results are shown in Table 6.

[0200] <Manufacturing examples for toners 2 and 3> Toners 2 and 3 were obtained in the same manner as in the manufacturing example of toner 1, except that the type of silica nanoparticles was changed as shown in Table 4.

[0201] <Example of Toner 4 manufacturing> • Binding resin 1,100 units • Paraffin wax (melting point 78°C) 4 parts • Nipex35 (Carbon Black) 6-piece set The above materials were pre-mixed in a Henschel mixer (product name: FM-10C, manufactured by Nippon Coke Co., Ltd.), and then melt-kneaded at 160°C using a twin-screw kneading extruder. The resulting mixture was cooled, coarsely ground in a hammer mill, and then finely ground in a turbo mill. The obtained finely ground material was classified using a multi-segment classifier utilizing the Coanda effect to obtain toner particles 2 with a weight-average particle size (D4) of 6.5 μm.

[0202] The obtained toner particles 2 were subjected to external treatment with silica fine particles A1 and B1 as described below. • Toner particles 2: 100 copies • Silica microparticles A1: 1.6 parts • Silica microparticles B1: 4.0 parts The above ingredients were mixed using a Henschel mixer (product name: FM-10C, manufactured by Nippon Coke Co., Ltd.) at a rotation speed of 67 seconds. -1 After mixing at room temperature with a rotation time of 2 minutes at 4000 rpm, the mixture was passed through an ultrasonic vibrating sieve with a mesh size of 54 μm to obtain toner 4.

[0203] <Manufacturing examples of toners 5 and 6> Toners 5 and 6 were obtained in the same manner as in the manufacturing example of toner 4, except that the type of silica fine particles was changed as shown in Table 4.

[0204] <Example of Toner 7 manufacturing> • Binding resin 1,100 units • Paraffin wax (melting point 78°C) 4 parts • Nipex35 (Carbon Black) 6-piece set The above materials were pre-mixed in a Henschel mixer (product name: FM-10C, manufactured by Nippon Coke Co., Ltd.), and then melt-kneaded at 160°C using a twin-screw kneading extruder. The resulting mixture was cooled, coarsely ground in a hammer mill, and then finely ground in a turbo mill. The obtained finely ground material was classified using a multi-segment classifier utilizing the Coanda effect to obtain toner particles 3 with a weight-average particle size (D4) of 6.5 μm.

[0205] The obtained toner particles 3 were subjected to external treatment with silica fine particles A1 as described below. • Toner particles 3: 100 copies • Silica microparticles A1: 1.6 parts The above ingredients were mixed using a Henschel mixer (product name: FM-10C, manufactured by Nippon Coke Co., Ltd.) at a rotation speed of 67 seconds. -1 After mixing at room temperature with a rotation time of 2 minutes at 4000 rpm, the mixture was passed through an ultrasonic vibrating sieve with a mesh size of 54 μm to obtain toner 7.

[0206] <Manufacturing examples for toners 8-22> Except for changing the type of silica microparticles as shown in Table 4, the manufacturing process was the same as for toner 7. Toners 8-22 were obtained. [Table 4] In the table, D4 ​​represents the weight-average particle size (μm) of the toner.

[0207] (Example of manufacturing magnetic carrier 2) Magnetic carrier 2 was obtained in the same manner as in the manufacturing example of magnetic carrier 1, except that the material of the coating resin was changed as described below. • Cyclohexyl methacrylate monomer 26.8% by mass • Methyl methacrylate monomer 8.6% by mass • Toluene 31.3% by mass • Methyl ethyl ketone 31.3% by mass • Azobisisobutyronitrile 2.0% by mass

[0208] (Example of manufacturing magnetic carrier 3) Magnetic carrier 3 was obtained in the same manner as in the manufacturing example of magnetic carrier 1, except that the material of the coating resin was changed as described below. • Methyl methacrylate monomer 35.4% by mass • Toluene 31.3% by mass • Methyl ethyl ketone 31.3% by mass • Azobisisobutyronitrile 2.0% by mass

[0209] (Manufacturing examples of developers 2-22) Two-component developers 2 to 22 were obtained in the same manner as the manufacturing example of developer 1, except that the magnetic carrier and toner were changed as shown in Table 5. [Table 5]

[0210] (evaluation) The evaluation was carried out in the same manner as in Example 1, except that two-component developers 2-22 were used. Examples 10-19 were evaluated as reference examples. The evaluation results are shown in Table 6.

[0211] This disclosure relates to the following configuration. (Composition 1) A toner having toner particles and silica fine particles A on the surface of the toner particles, The weight-average particle size of the toner is 4.0 to 15.0 μm. The carbon reduction rate when the silica fine particles A are washed with hexane is 5-70%. A toner characterized in that, under the following conditions, mass spectrometry is performed on the silica fine particles A while heating them at a sampling interval of 0.4 seconds, and the temperature at which the derivative of the nine-point moving average of the integral values ​​obtained by integrating the ionic intensity of mass number (M / z) 207 from 35°C is 4000 or more is 270°C or higher. Mass spectrometry conditions: (i) Heat 7.0 mg of silica fine particles A in a nitrogen atmosphere at a heating rate of 20°C / min from 35°C. (ii) The gas generated as the temperature rises is ionized under conditions of an ionization current of 50 μA and an ionization energy of 70 eV. (iii) The components contained in the ionized gas are subjected to mass spectrometry using a quadrupole mass spectrometer under the condition of an EM voltage of 1000V. (Configuration 2) The BET specific surface area of ​​the aforementioned silica fine particles A is 60 to 160 m². 2 The toner described in configuration 1 is / g. (Composition 3) The amount of moisture adsorbed by the silica fine particles A at a temperature of 30°C and a relative humidity of 80% is 0.01 to 0.07 cm³. 3 / m 2 The toner described in configuration 1 or 2. (Composition 4) The carbon reduction rate when the silica fine particles A are washed with hexane is 30-55%. The toner specified in one of configurations 1-3. (Composition 5) The toner according to any one of configurations 1 to 4, wherein the amount of carbon-based free components in the silica fine particles A is 3.0 parts by mass or more and 9.0 parts by mass or less per 100 parts by mass of the silica fine particles A. (Composition 6) The toner according to any one of configurations 1 to 5, wherein the number-average particle size of the primary particles of the silica fine particles A is 5 to 40 nm. (Composition 7) The toner according to any one of configurations 1 to 6, wherein the toner further contains silica fine particles B that are different from the silica fine particles A. (Composition 8) The toner according to configuration 7, wherein the number-average particle size of the primary particles of the silica fine particles B is 50 to 500 nm. (Composition 9) The toner according to configuration 7 or 8, wherein the number-average particle size of the primary particles of the silica fine particles B is 50 nm or more larger than the number-average particle size of the primary particles of the silica fine particles A. (Composition 10) The toner according to any one of configurations 1 to 9, wherein the content of the silica fine particles A is 0.2 to 3.0 parts by mass per 100 parts by mass of the toner particles. (Composition 11) The toner according to any one of configurations 1 to 10, wherein the silica fine particles A are compounds having a siloxane structure on their surface. (Composition 12) The toner according to any one of configurations 1 to 11, wherein the silica fine particles A are a silicone oil-treated product of silica fine particles treated with a cyclic siloxane. (Composition 13) A two-component developer having toner and a magnetic carrier, The magnetic carrier comprises magnetic carrier core particles and a resin coating layer on the surface of the magnetic carrier core particles. The resin in the resin coating layer contains monomer units of (meth)acrylic acid ester having alicyclic hydrocarbon groups, A two-component developer wherein the toner is the toner described in any of components 1 to 12. (Composition 14) The two-component developer according to configuration 13, wherein the resin in the resin coating layer further comprises monomer units made of macromonomers represented by the following formula (B). TIFF0007867853000009.tif18153(In formula (B), A represents a polymer of at least one compound selected from the group consisting of methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, styrene, acrylonitrile, and methacrylonitrile. R 3 (This is either H or CH3.) (Composition 15) A method for manufacturing toner to obtain the toner described in any of configurations 1 to 12, A process of mixing silica fine particle substrate and cyclic siloxane, and heat-treating it at a temperature of 300°C or higher to obtain a surface-treated product. A step of obtaining silica fine particles A by further treating the surface-treated material with silicone oil, and A step of mixing the silica fine particles A and toner particles to obtain the toner, A method for manufacturing SATURAL toner. (Composition 16) A method for manufacturing toner according to configuration 15, wherein the temperature at which the surface-treated material is further treated with silicone oil is 300°C or higher.

Claims

1. A toner having toner particles and silica fine particles A on the surface of the toner particles, The weight-average particle size of the toner is 4.0 to 15.0 μm. The silica fine particles A have a compound having a siloxane structure on their surface, The carbon reduction rate when the silica fine particles A are washed with hexane is 30-55%. A toner characterized in that, under the following conditions, mass spectrometry is performed on the silica fine particles A while heating them at a sampling interval of 0.4 seconds, and the temperature at which the derivative of the nine-point moving average of the integral values ​​obtained by integrating the ionic intensity of the obtained mass number (M / z) 207 from 35°C becomes 4000 or more is 270°C or higher. Mass spectrometry conditions: (i) Heat 7.0 mg of the silica fine particles A in a nitrogen atmosphere at a heating rate of 20°C / min from 35°C. (ii) The gas generated as the temperature rises is ionized under conditions of an ionization current of 50 μA and an ionization energy of 70 eV. (iii) The components contained in the ionized gas are subjected to mass spectrometry using a quadrupole mass spectrometer under the condition of an EM voltage of 1000V.

2. The BET specific surface area of ​​the silica fine particles A is 60 to 160 m². ２ The toner according to claim 1, wherein the toner is / g.

3. The amount of moisture adsorbed by the silica fine particles A at a temperature of 30°C and a relative humidity of 80% is 0.01 to 0.07 cm. ３ / m ２ The toner according to claim 1 or 2.

4. The toner according to claim 1 or 2, wherein the amount of carbon-based free components of the silica fine particles A is 3.0 parts by mass or more and 9.0 parts by mass or less per 100 parts by mass of the silica fine particles A.

5. The toner according to claim 1 or 2, wherein the number-average particle size of the primary particles of the silica fine particles A is 5 to 40 nm.

6. The toner further contains silica fine particles B, which are different from the silica fine particles A. Claim 5, wherein the number-average particle size of the primary particles of the silica fine particles B is 50 to 500 nm. The toner mentioned.

7. The toner according to claim 6, wherein the number-average particle size of the primary particles of the silica fine particles B is 50 nm or more larger than the number-average particle size of the primary particles of the silica fine particles A.

8. The toner according to claim 1 or 2, wherein the content of the silica fine particles A is 0.2 to 3.0 parts by mass per 100 parts by mass of the toner particles.

9. The toner according to claim 1 or 2, wherein the silica fine particles A are a silicone oil-treated product of silica fine particles treated with a cyclic siloxane.

10. The toner according to claim 1 or 2, wherein the temperature at which the derivative becomes 4000 or more is 340 to 400°C.

11. A two-component developer having toner and a magnetic carrier, The magnetic carrier comprises magnetic carrier core particles and a resin coating layer on the surface of the magnetic carrier core particles. The resin in the resin coating layer contains monomer units of (meth)acrylic acid ester having alicyclic hydrocarbon groups, A two-component developer wherein the toner is the toner described in claim 1 or 2.

12. The two-component developer according to claim 11, wherein the resin in the resin coating layer further comprises monomer units represented by the following formula (B). (In formula (B), A represents a polymer of at least one compound selected from the group consisting of methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, styrene, acrylonitrile, and methacrylonitrile. ３ is H or CH ３ (That is the case.)

13. A method for manufacturing toner to obtain the toner described in claim 1 or 2, A process of mixing a silica fine particle substrate with a cyclic siloxane and heat-treating it at a temperature of 330°C or higher to obtain a surface-treated product. A step of obtaining silica fine particles A by further treating the surface-treated material with silicone oil, and A step of mixing the silica fine particles A and toner particles to obtain the toner, A method for manufacturing SATURAL toner.

14. The method for manufacturing toner according to claim 13, wherein the temperature at which the surface-treated material is further treated with silicone oil is 300°C or higher.

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