Cyan toner, toner container unit, image forming apparatus, image forming method, and method for manufacturing cyan toner

Abstract

To provide a toner that is excellent in transfer property and resistance against contamination in an apparatus without deteriorating cleanability.SOLUTION: A cyan toner contains at least a binder resin and a colorant. When the intensity of the Raman spectra of toner particles is standardized to 1 in a wave number λ at which the total intensity obtained by adding up the Raman spectra of the toner particles obtained in a wave number region of 2600 cm-1 to 2800 cm-1 in Raman spectroscopy of the cyan toner indicates the maximum value, and when the integrated intensity of the spectra of the toner particles obtained in a wave number region of 2600 cm-1 to 3180 cm-1 is In, the average value of the In is Iave, and a value calculated with the following (formula 1) is a CH ratio, the number ratio of the toner articles in which the absolute value of the CH ratio is 7.0% or more to the entire toner particles is 1.0 number% or more and 20.0 number% or less. (Formula 1) CH ratio (%)=[(In-Iave) / Iave]×100.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a cyan toner, a developer, a toner container unit, an image forming apparatus, and an image forming method.

Background Art

[0002] In electrophotographic image formation, an electrostatic charge image (latent image) is formed on an electrostatic latent image carrier, charged toner is conveyed by a developer carrier, the latent image is developed to form a toner image, and then the toner image is transferred onto a recording medium such as paper and fixed by a method such as heating to obtain an output image. Further, a technique is known in which toner remaining on the electrostatic latent image carrier after transfer is recovered from the electrostatic latent image carrier by a cleaning member and discharged to a waste toner storage section.

[0003] In the above-described developing method, the toner particles supplied into the developing machine have variations in particle size, shape, charging characteristics, etc., and it is very difficult to control all the particles ideally. When the mixing state of the toner particles and the carrier is non-uniform and triboelectric charging cannot be obtained, or when the charging performance of the toner particles is low, control within the machine cannot be achieved and the toner scatters, causing contamination inside the machine. Also, if the adhesion force between some toner and the carrier, photoreceptor, or transfer belt is too strong, sufficient transfer cannot be achieved and the toner consumption increases. Even a small variation in the characteristics of the toner particles leads to an abnormality in the image system. Therefore, it is important to narrow the distribution of the characteristic values of each toner particle and improve the uniformity.

[0004] Patent Document 1 proposes narrowing the charge amount distribution and improving the transfer efficiency by using an external additive using an in-flame hydrolysis method. Patent Document 2 proposes improving the transfer rate by narrowing the shape distribution so that there are fewer overly deformed particles in addition to the selection of a specific release agent. In Patent Document 3, it is proposed that by selecting a specific resin, the abrasion resistance of the fixed image is improved, toner scattering is improved, and toner scattering is improved by narrowing the particle size distribution and spheroidizing the toner. Summary of the Invention Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a toner having excellent transferability and resistance to in-machine contamination without deteriorating the cleanability.

[0006] The present invention has been made in view of the above, and an object thereof is to provide a toner having excellent transferability and resistance to in-machine contamination without deteriorating the cleanability. Means for Solving the Problems

[0007] The present invention for solving the above problems is as described below. A cyan toner containing at least a binder resin and a colorant, wherein when the intensity of the Raman spectrum of each toner particle obtained in the wavenumber range of 2600 cm -1 ~2800 cm -1 in the Raman spectroscopy of the cyan toner is added up and the intensity of the Raman spectrum of each toner particle at the wavenumber λ showing the maximum value is normalized to 1, in the wavenumber range of 2600 cm -1 ~3180 cm -1 the integrated intensity of the spectrum of each toner particle obtained is defined as I n and the average value of the I n is defined as I ave and when the value calculated by the following (Formula 1) is defined as the CH ratio, a cyan toner in which the percentage of the number of toner particles having an absolute value of the CH ratio of 7.0% or more with respect to all toner particles is 1.0% by number or more and 20.0% by number or less. CH ratio (%) = [(I n -I ave ) / I ave × 100 ··· (Formula 1) Effects of the Invention

[0008] According to the present invention, it is possible to provide a toner excellent in transferability and stain resistance in the machine without deteriorating the cleaning property.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0010] In the toner of Patent Document 1, since non-uniformity in the adhesion amount and the degree of embedding cannot be avoided in the mixing step of mixing the toner base and the external additive, there is a limit to the improvement in uniformity, and the improvement in the transfer rate due to the narrowing of the charge amount distribution has not reached a sufficient level. In the toner of Patent Document 2, although an improvement in the transfer rate is recognized by spheroidizing the shape, since the cleaning blade passes through, it is a problem to achieve both cleaning properties. Although the toner of Patent Document 3 has a certain effect on reducing scattering by narrowing the particle size distribution, since non-uniformity in the particle size is inevitable during the granulation process, it has not reached a sufficient level. In addition, since the passage of the cleaning blade deteriorates due to spheroidization, it is a problem to achieve both improvement in toner scattering and cleaning properties. The toner of the present invention is a toner excellent in transferability and resistance to in-machine contamination without deteriorating the cleanability.

[0011] Hereinafter, embodiments of a cyan toner (hereinafter, also simply referred to as "toner"), a developer, a toner container unit, an image forming apparatus, and an image forming method according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments shown below, and can be changed within the scope that those skilled in the art can conceive, such as other embodiments, additions, modifications, deletions, etc., and is included in the scope of the present invention as long as the functions and effects of the present invention are exhibited in any aspect.

[0012] (Toner) The present invention is a cyan toner containing a binder resin and a colorant, and the number ratio of toner particles having an absolute value of the "CH rate" described later of 7.0% or more to all toner particles is 1.0% by number or more and 20.0% by number or less. The details will be described below.

[0013] (Outline of CH rate) The CH rate is a term taking the initials of Content Heterogeneity, and is an index defined to evaluate the non-uniformity of the raw material content in the toner. It evaluates how much the raw material content ratio of each toner particle deviates from the raw material content ratio at the time of toner creation. Naturally, it is preferable that the raw material content ratio of each toner particle does not deviate from the raw material content ratio at the time of toner creation.

[0014] (Calculation method of CH rate) The CH rate is calculated from the Raman spectrum of the toner. The "CH rate" in the present invention means that in the Raman spectroscopy of the toner, the wave number at which the total intensity obtained by adding up the Raman spectra of each toner particle in the wave number range of 2600 cm -1 ~2800 cm -1 shows the maximum value is defined as λ, and when the intensity of the Raman spectrum of each toner particle at the wave number λ is normalized to 1, 2600 cm-1 ~3180 cm -1 The integrated intensity of the spectrum of each toner particle obtained in the wavenumber range of is I n Let, and the average value of the above I n be I ave When, it is the value represented by the following (Equation 1). CH rate (%) = [(I n - I ave ) / I ave × 100 ··· (Equation 1) The Raman spectrum is measured using a Raman microscope. The apparatus to be used is not particularly limited. For example, it is measured using "XploRA PLUS" (manufactured by Horiba, Ltd.). After measuring the Raman spectrum of each toner particle and obtaining the spectra of 500 to 600 particles, the CH rate is calculated using the above (Equation 1).

[0015] <Measurement conditions of Raman spectrum> In the present invention, the Raman spectrum is measured under the following measurement conditions. (1) Selection of excitation laser For the measurement of the Raman spectrum, a laser with an excitation wavelength of 532 nm is used. The measurement is performed by irradiating each toner particle with the laser, and the laser intensity is adjusted to an intensity at which the toner does not melt. (2) Number of particles to be measured The spectral shape varies slightly for each toner particle. To evaluate the variation, 500 to 600 toner particles are measured. By measuring 500 to 600 toner particles, the measurement variation converges, and it becomes possible to compare different toners with each other. (3) Wavenumber range to be measured The analysis is performed using the wavenumber range of 2600 cm -1 ~3180 cm -1 Therefore, it is necessary to measure the wavenumber range including this range. (4) Focus adjustment conditions Adjustment is performed so that the focus is on the outermost surface of the toner particle. (5) Other setting items As other measurement conditions related to the resolution of the Raman spectrum, the measurement is performed with a 50x objective lens, and the measurement is performed with a resolution setting such that the plot interval in the wavenumber direction of the Raman spectrum is 0.5 cm -1 ~0.8 cm -1 to the extent.

[0016] <Sample Preparation Method> In order to measure toner particles one by one, a sample is prepared by dispersing the toner on a glass substrate.

[0017] <Correction of Raman Spectrum> Since the Raman spectrum also includes the influence of fluorescence and noise, it is desirable to perform baseline correction of the spectral data. The method of baseline correction is not particularly limited, but an example of the correction method is shown below. The baseline correction of the spectrum is performed using, for example, the software "Labspec6.0" (manufactured by Horiba, Ltd.). (1) Extract the wavenumber region of the measured Raman spectrum at 2600 cm -1 ~3180 cm -1 Extract at. (2) Execute baseline correction in (1) above with "Degree: 1", "Maximum number of points: 2", and "Number of noise points: 0".

[0018] <Normalization of Raman Spectrum> Since the intensity of the Raman spectrum varies depending on the size and shape of the measurement object, the type of raw material, etc., it is not possible to simply compare the Raman spectrum intensities of different toners. Therefore, by performing normalization processing on the Raman spectrum, different toners can be compared. The normalization processing is performed using data editing software (for example, Excel, etc.) on the spectrum corrected for the baseline.

[0019] Normalization is performed by the following method. (1) Calculate the total spectrum obtained by adding up all the Raman spectra as shown in Fig. 1, and at 2600 cm -1~2800 cm -1 Determine the wavenumber λ at which the total spectrum in -1 exhibits the maximum intensity. (2) As shown in Figure 2, for the Raman spectrum of the n-th particle, determine the correction factor X(n) such that the intensity at the wavenumber λ becomes 1, and multiply the correction factor X(n) across the entire wavenumber range to normalize the spectrum intensity. Hereinafter, the spectrum after the above normalization is referred to as the normalized spectrum. Perform this for the Raman spectra of all the measured particles.

[0020] <Excluding noise data> In the measurement of Raman spectra, there may be cases where data that are noise such as dust are acquired, and if these are included in the CH rate calculation, correct evaluation may not be possible. Therefore, the noise data are excluded as follows. For the normalized spectrum of the n-th particle in (2) above, calculate the area S(n) of the spectrum. Perform this for all the measured particles. Calculate the standard deviation σ(S) of S(n) for all the particles, and for particles (n) that do not satisfy S(n) - 2×σ(S) ≤ S(n) ≤ S(n) + 2×σ(S), treat them as error data and exclude them from the calculation target of the CH rate.

[0021] <Calculation of CH rate> Figure 3 is a diagram showing a method for calculating the average spectrum intensity. Using the particles (n) that were not excluded by the above noise data exclusion process, obtain the average spectrum. Figure 4 shows the average spectrum obtained in Figure 3 and the spectra of the particles (n) arranged in the figure. 2600 cm of particle (n) -1 ~3180 cm -1 Calculate the integrated intensity I n in the range, and calculate the average value using the I n of all the particles, and denote it as I ave . The difference in the integrated intensity between particle (n) and the average spectrum in the range of 2600 cm -1 ~3180 cm -1 is I n - Iave It becomes as follows. As the calculation of the change rate with respect to the average, the CH rate is calculated using the following (Equation 1). CH rate (%) = [(I n - I ave ) / I ave × 100 ··· (Equation 1) I n : The integrated intensity of the Raman spectrum of the n-th particle at 2600 cm -1 ~ 3180 cm -1 I ave : The average value of I n for all the particles

[0022] Since the intensity of the Raman spectrum varies depending on the type of raw material used, the CH rate is not calculated by the difference between In and I ave , but is calculated as a rate of change as in (Equation 1) similar to the coefficient of variation (CV).

[0023] As a result of intensive studies on the problem of achieving both transferability, resistance to in-machine contamination, and cleanability, the inventors have found that in the CH rate indicating the non-uniformity of the resin component content in the toner, it is important that the proportion of particles with an absolute value of the CH rate of 7.0% or more is 1.0 number % or more and 20.0 number % or less. If the proportion of particles with an absolute value of the CH rate of 7.0% or more exceeds 20.0 number %, the effect of suppressing in-machine contamination and the effect of improving transferability due to toner scattering become insufficient, which is not preferable. On the other hand, when the absolute value of the CH rate is less than 1.0 number %, although the background contamination toner will also be greatly reduced, the dam in the cleaning blade part formed by the conventional background contamination toner may become insufficient, and there is a possibility of poor cleaning.

[0024] In addition, when the proportion of particles with an absolute value of the CH rate of 7.0% or more is 5.0 number % or more and 15.0 number % or less, a further effect of suppressing in-machine contamination, an effect of improving transferability, and good cleanability can be obtained.

[0025] ​The ratio of toner particles with an absolute value of the CH rate of 15.0% or more is preferably 1.0% or less by number, and more preferably 0.5% or less by number. The threshold value of the absolute value of the CH rate of 15.0% is approximately outside the tail of the CH rate distribution, and toner particles with an absolute value of the CH rate of 15.0% or more are toner particles with extremely different compositions deviating from the target toner composition ratio. Since the ratio of such toner particles with extremely different compositions is small, transfer failure does not occur, and in particular, it does not scatter inside the machine. By reducing the ratio of toner particles with an absolute value of the CH rate of 15.0% or more, it is possible to improve the resistance to internal contamination of the machine.

[0026] The median value of the CH rate is preferably -2.0% or more. By having the median value of the CH rate be -2.0% or more, toner scattering due to carrier deterioration does not occur, and it is possible to improve the resistance to internal contamination of the machine. Since the CH rate evaluates the deviation from the average spectrum, the sum of the CH rates of all toner particles becomes zero. However, when there is a bias in the component distribution, especially when there are some particles with extremely different compositions, the median value of the CH rate will not be zero.

[0027] When the median value of the CH rate is negative, it means that there are toner particles with extremely high CH rates, that is, a large amount of resin components. Conversely, when the median value of the CH rate is positive, it means that there are toner particles with extremely low CH rates, that is, a small amount of resin components, for example, toner particles with an extremely large amount of colorants.

[0028] For toner particles with a high CH rate and a large amount of resin components, there is a high possibility that an excessive amount of release agent is contained. Toner particles containing a large amount of release agent are likely to be spent on the carrier, resulting in a decrease in charging ability due to carrier contamination. Therefore, the higher the median value of the CH rate, the larger the ratio of toner particles with a low CH rate and less likely to cause carrier contamination. It is preferable to prevent the median value of the CH rate from becoming a low value.

[0029] The manufacturing method of the toner of the present invention is not particularly limited. In the kneading and pulverizing method, it is desirable to pulverize in a state where the raw materials are more uniformly finely dispersed in the binder resin, such as by pre-fine dispersion of the raw materials, increasing the intensity of the kneading process, and preventing re-aggregation by temperature control.

[0030] As an example of the chemical method, the dissolution-suspension method will be described in detail. After dissolving a toner composition containing at least a binder resin, a colorant, and a release agent in an organic solvent, the material is refined by a shearing force or a collision force. At this time, by using the shearing force and the collision force in combination, it is possible to efficiently reduce the toner having a non-uniform composition with an absolute value of the CH rate of 7.0% or more.

[0031] The dispersion method is not particularly limited, but for the fine dispersion by shear, a method of pulverizing the material with a high shearing force generated in a narrow gap between a rotor and a stator is preferably used. For the fine dispersion by collision, a method of pulverizing the material by the collision between the beads and between the beads and the vessel by filling the vessel with beads such as zirconia and rotating them is preferably used.

[0032] The pulverization by collision is particularly effective for large materials exceeding 1 μm, while the pulverization by shear is effective for further refining submicron-order materials. Since the two methods have different main pulverization target regions, it is particularly preferable to use the two methods in combination because the uniformity of the material can be improved by using them in combination. The order of dispersion by shear and dispersion by collision is not limited.

[0033] In order to efficiently refine the material, in the case of microdispersion by shear, it is preferable that the peripheral speed of the rotor exceeds 12 m / s. Also, in the case of pulverization by collision, it is preferable that the disk peripheral speed be 6 m / s or more, and more preferably 10 m / s to 12 m / s. In the case of pulverization by collision, if the disk peripheral speed is less than 6 m / s, sufficient pulverization energy by collision cannot be obtained, and uneven distribution of the beads occurs, resulting in insufficient dispersion. Conversely, if the disk peripheral speed is increased too much, there is a concern that overdispersion will occur, leading to deterioration of cleaning performance due to a decrease in the ground soil toner. There are also risks such as an increase in liquid temperature and re-aggregation due to overdispersion.

[0034] The media diameter is preferably 0.5 mm or less, and more preferably 0.3 mm or less. The smaller the beads, the greater the total surface area of the beads, so the dispersion opportunity by collision increases and the dispersion efficiency improves. If it is too small, it is necessary to narrow the mesh opening of the screen for separating the beads from the process liquid, so there is a risk that the flow rate cannot be achieved, the liquid temperature rises, and re-aggregation occurs.

[0035] Furthermore, in order to reduce toner particles with a non-uniform composition such that the absolute value of the CH rate exceeds 7.0%, it is also effective to add and disperse an inorganic substance harder than organic substances such as a colorant and a release agent in the dispersion liquid. The inorganic substance is not particularly limited, but as an example, the case of adding montmorillonite, which is an organically modified layered inorganic mineral, will be described below.

[0036] After dissolving a toner composition containing an organically modified layered inorganic mineral in addition to at least a binder resin, a colorant, and a release agent in an organic solvent, a media type disperser is used to refine the material by the collision force. When the composition contains an organically modified layered inorganic mineral, compared to the case where it does not contain an organically modified layered inorganic mineral, it is possible to more efficiently microdisperse the material and reduce toner particles with a non-uniform composition. This is because in addition to between the beads and between the beads and the vessel, collision opportunities also occur between the beads and the inorganic substance and between the vessel and the inorganic substance, so it is possible to effectively disperse the organic substance with low hardness. In rotor-stator type shear dispersion, even if an inorganic substance is added, the pulverization efficiency does not increase, and it is important to utilize the inorganic substance as a grinding medium.

[0037] The addition amount of the inorganic substance is preferably 0.2 mass% to 2.0 mass% with respect to the total solid content, and more preferably 0.7 mass% to 1.5 mass%. When the addition amount is 0.2 mass% to 2.0 mass%, the function as a grinding medium is sufficiently exhibited, and the uniformity of the CH rate is improved.

[0038] Also, regarding the shape, size, etc. of the toner, there are no particular restrictions, and it can be appropriately selected according to the purpose. However, it is preferable to have the following, such as average circularity, volume average particle diameter, the ratio of volume average particle diameter to number average particle diameter (volume average particle diameter / number average particle diameter), etc.

[0039] The average circularity is the average value of the circularity obtained by dividing the perimeter of a circle equivalent to the shape and projected area of the toner by the perimeter of the projected image of the toner. For example, 0.950 to 0.980 is preferable, and 0.960 to 0.975 is more preferable. In addition, it is preferable that the particles with an average circularity of less than 0.950 are 15.0% or less in terms of the number.

[0040] When the average circularity is 0.950 or more, satisfactory transferability and high-quality images without fogging can be obtained. Also, when it is 0.980 or less, in an image forming system employing blade cleaning or the like, there is no occurrence of poor cleaning on the photoreceptor and transfer belt, etc. In the case of forming an image with a high image area ratio such as a photographic image, toner that forms an untransferred image due to paper feeding failure or the like does not accumulate as residual transferred toner on the photoreceptor and cause image background staining, and the charging roller or the like that contact-charges the photoreceptor is not contaminated, so the original charging ability can be exhibited.

[0041] The average circularity can be measured using a flow-type particle image analyzer ("FPIA-2100", manufactured by Sysmex Corporation), and analysis can be performed using analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10).

[0042] For a specific example, add 0.1 to 0.5 mL of an aqueous solution of a 10 mass% surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to a 100 mL glass beaker, add 0.1 to 0.5 g of each toner, stir with a microspatula, and then add 80 mL of ion-exchanged water. Disperse the obtained dispersion with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.) for 3 minutes. Measure the shape and distribution of the toner with the FPIA-2100 until a concentration of 5,000 to 15,000 particles / μL is obtained.

[0043] In terms of the measurement reproducibility of the average circularity, it is important that the concentration of the dispersion is 5,000 to 15,000 particles / μL. In order to obtain the concentration of the dispersion, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant added and the amount of toner. The amount of surfactant required varies depending on the hydrophobicity of the toner, similar to the measurement of the toner particle size described above. If too much is added, noise due to bubbles will occur, and if too little is added, the toner cannot be sufficiently wetted, resulting in insufficient dispersion. Also, the amount of toner added varies depending on the particle size, and it is necessary to add less for small particle sizes and more for large particle sizes. When the toner particle size is 3 μm to 10 μm, the dispersion concentration can be adjusted to 5,000 particles / μL to 15,000 particles / μL by adding 0.1 g to 0.5 g of toner.

[0044] There are no particular restrictions on the volume average particle size of the toner, and it can be appropriately selected according to the purpose. It is possible, for example, 3 μm to 10 μm is preferable, and 4 μm to 7 μm is more preferable. If the volume average particle diameter is less than 3 μm, in the two-component developer, toner may fuse to the surface of the carrier during long-term agitation in the developing device, which may reduce the charging ability of the carrier. If it exceeds 10 μm, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of toner in the developer is maintained, the variation in the particle diameter of the toner may increase.

[0045] As the ratio (volume average particle diameter / number average particle diameter) of the volume average particle diameter and the number average particle diameter in the toner, 1.00 to 1.25 is preferable, and 1.00 to 1.15 is more preferable. The volume average particle diameter and the ratio (volume average particle diameter / number average particle diameter) of the volume average particle diameter and the number average particle diameter can be measured using a particle size analyzer (“Multisizer III”, manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm and analyzed using analysis software (Beckman Coulter Mutlisizer 3 Version 3.51).

[0046] Specifically, 0.5 mL of an aqueous solution of a 10 mass% surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 mL glass beaker, 0.5 g of each toner is added and stirred with a microspatula, and then 80 mL of ion-exchanged water is added. The obtained dispersion is dispersed for 10 minutes using an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion can be measured using the Multisizer III with Isoton III (manufactured by Beckman Coulter, Inc.) as the measurement solution.

[0047] The measurement is performed by dropping the toner sample dispersion so that the concentration indicated by the device becomes 8 ± 2%. From the viewpoint of measurement reproducibility of the particle diameter, it is important to set the concentration to 8 ± 2%. Within this concentration range, no error will occur in the particle diameter.

[0048] <Toner raw material> The toner of the present invention can contain at least a binder resin in a toner base, and can contain other components such as a release agent as needed, and an external additive can be added as needed.

[0049] <<Binder resin>> The binder resin is not particularly limited and can be appropriately selected according to the purpose. For example, polyester resin, silicone resin, styrene-acrylic resin, styrene resin, acrylic resin, epoxy resin, diene resin, phenol resin, terpene resin, coumarin resin, amide-imide resin, butyral resin, urethane resin, ethylene vinyl acetate resin, etc. can be mentioned. These may be used alone or in combination of two or more. Among these, polyester resin, and a resin obtained by combining a polyester resin and the above other binder resins are preferable in terms of excellent low-temperature fixability and sufficient flexibility even when the molecular weight is reduced.

[0050] - Polyester resin - The polyester resin is not particularly limited and can be appropriately selected according to the purpose, but an unmodified polyester resin or a modified polyester resin is preferable. These may be used alone or in combination of two or more.

[0051] -- Unmodified polyester resin -- The unmodified polyester resin is not particularly limited and can be appropriately selected according to the purpose. For example, a resin obtained by esterifying a polyol represented by the following general formula (1) and a polycarboxylic acid represented by the following general formula (2), a crystalline polyester resin, etc. can be mentioned.

[0052]

Chemical formula

[0053] However, in the general formula (1), A represents an alkyl group having 1 to 20 carbon atoms, an alkylene group, an aromatic group which may have a substituent, or a heteroaromatic group, and m represents an integer of 2 to 4. In the general formula (2), B represents an alkyl group having 1 to 20 carbon atoms, an alkylene group, an aromatic group or a heteroaromatic group which may have a substituent, and n represents an integer of 2 to 4.

[0054] The polyol represented by the general formula (1) is not particularly limited and can be appropriately selected according to the purpose. For example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetra methyleneglycol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. can be mentioned. These may be used alone or in combination of two or more.

[0055] The polycarboxylic acid represented by the general formula (2) is not particularly limited and can be appropriately selected according to the purpose. For example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isooctyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra(methylene carboxyl)methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, Empol trimer acid, etc., cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, butanetetracarboxylic acid, diphenylsulfonetetracarboxylic acid, ethylene glycol bis(trimeric acid), etc. These may be used alone or in combination of two or more.

[0056] --Modified polyester resin-- The modified polyester resin is not particularly limited and can be appropriately selected according to the purpose. For example, resins obtained by subjecting an active hydrogen group-containing compound and a polyester capable of reacting with the active hydrogen group-containing compound (hereinafter sometimes referred to as "polyester prepolymer") to an extension reaction and / or a crosslinking reaction can be mentioned. The extension reaction and / or crosslinking reaction may be stopped with a reaction terminator (such as a monoamine blocked with diethylamine, dibutylamine, butylamine, laurylamine, a ketimine compound, etc.) as necessary.

[0057] ---Active hydrogen group-containing compound--- In the aqueous phase, the active hydrogen group-containing compound acts as an extender, a crosslinking agent, etc. when the polyester prepolymer undergoes an elongation reaction, a crosslinking reaction, etc.

[0058] The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected according to the purpose. Among them, when the polyester prepolymer is an isocyanate group-containing polyester prepolymer described later, amines are preferable in that high molecular weight can be achieved.

[0059] The active hydrogen group is not particularly limited and can be appropriately selected according to the purpose. For example, a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, etc. can be mentioned. These may be contained alone or in combination of two or more.

[0060] The amines as the active hydrogen group-containing compound are not particularly limited and can be appropriately selected according to the purpose. For example, diamines, polyamines with a valence of 3 or more, amino alcohols, amino mercaptans, amino acids, those in which the amino groups of these amines are blocked, etc. can be mentioned.

[0061] Examples of the diamine include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, etc.); alicyclic diamines (4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diamine cyclohexane, isophoronediamine, etc.); aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.). Examples of the polyamine with a valence of 3 or more include diethylenetriamine, triethylenetetramine, etc. Examples of the amino alcohol include ethanolamine, hydroxyethylaniline, etc. Examples of the amino mercaptan include aminoethyl mercaptan, aminopropyl mercaptan, etc.

[0062] Examples of the amino acid include aminopropionic acid and amino caproic acid. Examples of the blocked amino groups of these amines include ketimine compounds and oxazolidone compounds obtained from any of these amines (diamines, polyamines with a valency of 3 or more, amino alcohols, amino mercaptans, amino acids, etc.) and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.).

[0063] These may be used alone or in combination of two or more. Among these, the amines are particularly preferably diamines or a mixture of diamines and a small amount of polyamines with a valency of 3 or more.

[0064] ---Polymer capable of reacting with active hydrogen group-containing compound--- The polymer capable of reacting with the active hydrogen group-containing compound is not particularly limited as long as it has at least a group capable of reacting with the active hydrogen group-containing compound, and can be appropriately selected according to the purpose. Among them, a urea bond-forming group-containing polyester resin (RMPE) is preferable, and an isocyanate group-containing polyester prepolymer is more preferable in terms of excellent high fluidity and transparency during melting, easy adjustment of the molecular weight of the polymer component, excellent oil-free low-temperature fixability and releasability in dry toner.

[0065] The isocyanate group-containing polyester prepolymer is not particularly limited and can be appropriately selected according to the purpose. For example, polycondensates of polyols and polycarboxylic acids, those obtained by reacting an active hydrogen group-containing polyester resin with a polyisocyanate, etc. may be mentioned.

[0066] The polyol is not particularly limited and can be appropriately selected according to the purpose. For example, alkylene glycols (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.), alkylene ether glycols (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.), polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.), phenols with three or more valences (phenol novolak, cresol novolak, etc.), polyols with three or more valences such as alkylene oxide adducts of polyphenols with three or more valences; mixtures of diols and polyols with three or more valences; and the like. Examples include bisphenol F, bisphenol S, etc.), polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.), phenols with three or more valences (phenol novolak, cresol novolak, etc.), polyols with three or more valences such as alkylene oxide adducts of polyphenols with three or more valences; mixtures of diols and polyols with three or more valences; and the like.

[0067] These may be used alone or in combination of two or more. Among these, the polyol is preferably the diol alone or a mixture of the diol and a small amount of the polyol with three or more valences.

[0068] As the diol, it is preferable to mainly contain alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols (bisphenol A ethylene oxide 2-mol adduct, bisphenol A ethylene oxide 3-mol adduct). Also, for the purpose of adjusting the molecular weight and molecular weight mobility, alkylene glycols (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, etc.) may be used.

[0069] The content of the polyol in the isocyanate group-containing polyester prepolymer is not particularly limited and can be appropriately selected according to the purpose. For example, 0.5% by mass to 40% by mass is preferable, 1% by mass to 30% by mass is more preferable, and 2% by mass to 20% by mass is particularly preferable. If the content is less than 0.5% by mass, the hot offset resistance deteriorates, and it may be difficult to achieve both the storage stability and the low-temperature fixability of the toner. If it exceeds 40% by mass, the low-temperature fixability may deteriorate.

[0070] The polycarboxylic acid is not particularly limited and can be appropriately selected according to the purpose. For example, alkylene dicarboxylic acids (such as succinic acid, adipic acid, sebacic acid); alkenylene dicarboxylic acids (such as maleic acid, fumaric acid); aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid); polycarboxylic acids with three or more valences (such as aromatic polycarboxylic acids with 9 to 20 carbon atoms such as trimellitic acid, pyromellitic acid, etc.) and the like can be mentioned. These may be used alone or in combination of two or more.

[0071] Among these, the polycarboxylic acid is preferably an alkenylene dicarboxylic acid having 4 to 20 carbon atoms or an aromatic dicarboxylic acid having 8 to 20 carbon atoms. In addition, instead of the polycarboxylic acid, an anhydride of a polycarboxylic acid, a lower alkyl ester (such as methyl ester, ethyl ester, isopropyl ester, etc.) and the like may be used.

[0072] The mixing ratio of the polyol and the polycarboxylic acid is not particularly limited and can be appropriately selected according to the purpose. The equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] of the polyol and the carboxyl group [COOH] of the polycarboxylic acid is preferably 2 / 1 to 1 / 1, more preferably 1.5 / 1 to 1 / 1, and particularly preferably 1.3 / 1 to 1.02 / 1.

[0073] There are no particular restrictions on the polyisocyanate, and it can be appropriately selected according to the purpose. For example, aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetramethylhexane diisocyanate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates (toluene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4'-diisocyanate, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 3-methyldiphenylmethane-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, etc.); araliphatic diisocyanates (α,α,α',α'-tetramethylxylylene diisocyanate, etc.); isocyanurates (tris-isocyanatoalkyl-isocyanurate, triisocyanatocycloalkyl-isocyanurate, etc.); phenol derivatives thereof; blocked ones with oxime, caprolactam, etc. Examples thereof include those blocked with the above. These may be used alone or in combination of two or more.

[0074] There are no particular restrictions on the mixing ratio of the polyisocyanate and the active hydrogen group-containing polyester resin (hydroxyl group-containing polyester resin), and it can be appropriately selected according to the purpose. The equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] of the polyisocyanate and the hydroxyl group [OH] of the hydroxyl group-containing polyester resin is preferably 5 / 1 to 1 / 1, more preferably 4 / 1 to 1.2 / 1, and particularly preferably 3 / 1 to 1.5 / 1. When the equivalent ratio [NCO] / [OH] is less than 1 / 1, the offset resistance may deteriorate. When it exceeds 5 / 1, the low-temperature fixing property may deteriorate.

[0075] The content of the polyisocyanate in the isocyanate group-containing polyester prepolymer is not particularly limited and can be appropriately selected according to the purpose. 0.5% by mass to 40% by mass is preferable, 1% by mass to 30% by mass is more preferable, and 2% by mass to 20% by mass is particularly preferable. When the content is less than 0.5% by mass, the hot offset resistance deteriorates, and it may be difficult to achieve both storage stability and low-temperature fixing property. When it exceeds 40% by mass, the low-temperature fixing property may deteriorate.

[0076] The average number of isocyanate groups contained per molecule of the isocyanate group-containing polyester prepolymer is preferably 1 or more, more preferably 1.2 to 5, and still more preferably 1.5 to 4. When the average number is less than 1, the molecular weight of the polyester resin (RMPE) modified with a urea bond-forming group may be low, and the hot offset resistance may deteriorate.

[0077] The mixing ratio of the isocyanate group-containing polyester prepolymer and the amines is not particularly limited and can be appropriately selected according to the purpose. The mixing equivalent ratio [NCO] / [NHx] of the isocyanate groups [NCO] in the isocyanate group-containing polyester prepolymer and the amino groups [NHx] in the amines is preferably 1 / 3 to 3 / 1, more preferably 1 / 2 to 2 / 1, and particularly preferably 1 / 1.5 to 1.5 / 1. When the mixing equivalent ratio ([NCO] / [NHx]) is less than 1 / 3, the low-temperature fixing property may decrease, and when it exceeds 3 / 1, the molecular weight of the urea-modified polyester resin may be low, and the hot offset resistance may deteriorate.

[0078] ---Synthesis method of a polymer capable of reacting with an active hydrogen group-containing compound--- The method for synthesizing the polymer capable of reacting with the active hydrogen group-containing compound is not particularly limited and can be appropriately selected according to the purpose. For example, in the case of the isocyanate group-containing polyester prepolymer, the polyol and the polycarboxylic acid are heated to 150°C to 280°C in the presence of a known esterification catalyst (such as titanium tetrabutoxide, dibutyltin oxide, etc.), and generated while appropriately reducing the pressure as necessary, and water is distilled off to obtain a hydroxyl group-containing polyester. Then, at 40°C to 140°C, the polyisocyanate is reacted with the hydroxyl group-containing polyester to synthesize it. Examples of such methods can be mentioned.

[0079] The weight average molecular weight (Mw) of the polymer capable of reacting with the active hydrogen group-containing compound is not particularly limited and can be appropriately selected according to the purpose. In terms of the molecular weight distribution by GPC (gel permeation chromatography) of the THF-soluble component, 3,000 to 40,000 is preferable, and 4,000 to 30,000 is more preferable. If the weight average molecular weight (Mw) is less than 3,000, the storage stability may deteriorate, and if it exceeds 40,000, the low-temperature fixing property may deteriorate.

[0080] The measurement of the weight average molecular weight (Mw) can be carried out, for example, as follows. First, the column is stabilized in a heat chamber at 40°C, and tetrahydrofuran (THF) is flowed as the column solvent at a flow rate of 1 mL per minute at this temperature. A 50 μL to 200 μL of a tetrahydrofuran sample solution of the resin with the sample concentration adjusted to 0.05 to 0.6 mass% is injected for measurement. When measuring the molecular weight of the sample, it is calculated from the relationship between the logarithmic value of the calibration curve created by several monodisperse polystyrene standard samples and the count number of the molecular weight distribution of the sample.

[0081] As the standard polystyrene sample for preparing the calibration curve, those with molecular weights of 6×10, 2.1×10 2 , 4×10 2 , 1.75×10 4 , 1.1×10 5 , 3.9×105 and 8.6×10 5 and 2×10 6 and 4.48×10 6 It is preferable to use at least about 10 standard polystyrene samples. As the detector, an RI (refractive index) detector can be used.

[0082] [[Release agent]] The release agent is not particularly limited and can be appropriately selected according to the purpose. For example, plant waxes (such as carnauba wax, cotton wax, wood wax, rice wax, etc.), animal waxes (such as beeswax, lanolin, etc.), mineral waxes (such as ozokerite, ceresin, etc.), petroleum waxes (such as paraffin, microcrystalline, petrolatum, etc.) and other waxes; synthetic hydrocarbon waxes (such as Fischer-Tropsch wax, polyethylene wax, etc.), synthetic waxes (such as esters, ketones, ethers, etc.) and other substances other than natural waxes; fatty acid amides such as 1,2-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, chlorinated hydrocarbons; polyacrylate homopolymers or copolymers (such as n-stearyl methacrylate-ethyl methacrylate copolymer, etc.) with a long-chain alkyl group in the side chain, which are low-molecular-weight crystalline polymers; and the like.

[0083] Among these, Fischer-Tropsch wax, paraffin wax, microcrystalline wax, monoester wax, and rice wax are preferable in that they generate less unnecessary volatile organic compounds during fixing.

[0084] As the release agent, commercially available products can be used. Examples of the microcrystalline wax include "HI-MIC-1045", "HI-MIC-1070", "HI-MIC-1080", "HI-MIC-1090" manufactured by Nippon Seiro Co., Ltd., "Be Square 180 White", "Be Square 195" manufactured by Toyo Adres Co., Ltd., "BARECO C-1035" manufactured by WAXPetrolife Co., "CRAYVALLAC WN-1442" manufactured by Cray Vally Co., and the like.

[0085] The melting point of the release agent is not particularly limited and can be appropriately selected according to the purpose, but is preferably 60°C to 100°C, more preferably 65°C to 90°C. When the melting point is 60°C or higher, even during high-temperature storage at about 30 to 50°C, the bleeding of the release agent from the toner matrix can be suppressed, and the heat-resistant storage stability can be maintained well. When it is 100°C or lower, it is preferable because cold offset is less likely to occur during fixing at low temperatures.

[0086] The melting point is measured by DSC. For example, it can be measured under the following measurement conditions using TA-60WS and DSC-60 manufactured by Shimadzu Corporation. (Measurement conditions) Sample container: Aluminum sample pan (with lid) Sample amount: 5 mg Reference: Aluminum sample pan (10 mg of alumina) Atmosphere: Nitrogen (flow rate 50 mL / min) Temperature conditions 1st. Heating Start temperature: 20°C, Heating rate: 10°C / min, End temperature: 150°C, Holding time: None 1st. Cooling Cooling rate: 10°C / min, End temperature: 20°C, Holding time: None 2nd. Heating Heating rate: 10°C / min, End temperature: 150°C The measurement results are analyzed using data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. The melting point uses the temperature at the peak top of the endothermic peak measured in the 2nd. heating.

[0087] The release agent preferably exists in a state of being dispersed in the toner base particles. For this purpose, it is preferable that the release agent and the binder resin are incompatible with each other. There is no particular limitation on the method for finely dispersing the release agent in the toner base particles, and it can be appropriately selected according to the purpose and examples thereof include a method of dispersing by applying a shearing force during kneading in toner production.

[0088] The dispersion state of the release agent can be confirmed by observing a thin film section of the toner particles with a transmission electron microscope (TEM). The dispersion diameter of the release agent is preferably small, but if it is too small, bleeding during fixing may be insufficient. Therefore, if the release agent can be confirmed at a magnification of 10,000 times, it means that the release agent exists in a dispersed state. If the release agent cannot be confirmed at a magnification of 10,000 times, even if it was finely dispersed, bleeding during fixing will be insufficient.

[0089] The content of the release agent in the toner is not particularly limited and can be appropriately selected according to the purpose, but 3% by mass to 15% by mass is preferable, and 5% by mass to 10% by mass is more preferable. When the content of the release agent in the toner is 3% by mass or more (especially 5% by weight or more), the hot offset resistance does not deteriorate, and when it is 15% by mass or less (especially 10% by mass or less), the bleeding amount of the release agent during fixing does not become excessive and the heat-resistant storage stability does not deteriorate, which is preferable.

[0090] <<Other Components>> -Colorant- There is no particular limitation on the colorant used in the toner, and it can be appropriately selected from known colorants according to the purpose.

[0091] The color of the toner is cyan and contains at least one cyan colorant appropriately selected.

[0092] Examples of cyan coloring pigments include C.I. Pigment Blue 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 60; C.I. Vat Blue 6; C.I. Acid Blue 45; copper phthalocyanine pigments in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton, Green 7, Green 36, and the like.

[0093] The content of the colorant in the toner is preferably 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass. If the content is less than 1% by mass, the coloring power of the toner may decrease. If it exceeds 15% by mass, poor dispersion of the colorant in the toner may occur, leading to a decrease in coloring power and a decrease in the electrical properties of the toner.

[0094] The colorant may be used as a masterbatch compounded with a resin. Such a resin is not particularly limited, but from the viewpoint of compatibility with the binder resin, it is preferable to use a binder resin or a resin having a structure similar to that of the binder resin.

[0095] The masterbatch can be produced by applying high shear force to mix or knead the resin and the colorant. At this time, it is preferable to add an organic solvent to enhance the interaction between the colorant and the resin. Also, the so-called flushing method can directly use the wet cake of the colorant, which is suitable in that it does not require drying. The flushing method is a method of mixing or kneading an aqueous paste containing water of the colorant together with a resin and an organic solvent, transferring the colorant to the resin side, and removing water and the organic solvent. For mixing or kneading, for example, a high-shear dispersion device such as a three-roll mill can be used.

[0096] <Organically modified layered inorganic mineral> The organic-modified layered inorganic mineral is an organic-modified layered inorganic mineral in which at least a part of the ions existing between the layers of the layered inorganic mineral are modified with organic ions. The layered inorganic mineral is a layered inorganic mineral formed by stacking layers with a thickness of several nm. The term "modified" is synonymous with introducing organic ions into the ions existing between the layers of the layered inorganic mineral, and in a broad sense, it is intercalation.

[0097] The layered inorganic mineral exhibits the greatest effect when disposed near the surface, and it is known that it is likely to be disposed near the surface. Also, in the organic-modified layered inorganic mineral of the present invention, it is desirable that it be contained in toner particles at a uniform ratio regardless of the size of the toner particle diameter. For this reason, the organic-modified layered inorganic mineral is uniformly disposed near the surface of any toner particle. As a result, for example, in toner particles with a small particle diameter, the content rate of the organic-modified layered inorganic mineral becomes small, and therefore the ratio of the organic-modified layered inorganic mineral disposed on the surface decreases, the surface of the toner particle becomes relatively soft, and the external additive added to the toner matrix is easily embedded, thereby avoiding the phenomenon that the desorption of the external additive advantageous for imparting fluidity to the toner is inhibited.

[0098] Here, the state of existence of the organic-modified layered inorganic mineral in the toner can be confirmed by embedding a sample of toner particles in an epoxy resin or the like and cutting it with a microtome or an ultramicrotome, and observing the cross-section of the toner with a scanning electron microscope (SEM) or the like. In the case of observation by SEM, it is preferable to confirm with a backscattered electron image, because the presence of the organic-modified layered inorganic mineral can be observed with strong contrast. Also, a sample in which toner particles are embedded in an epoxy resin or the like may be cut with an ion beam using FIB-STEM (HD-2000, manufactured by Hitachi, Ltd.) and the cross-section of the toner may be observed. Also in this case, it is preferable to confirm with a backscattered electron image because of the ease of visual recognition.

[0099] In addition, the vicinity of the toner surface referred to in the present invention is defined as a region of 0 nm to 300 nm from the outermost surface of the toner to the inside of the toner in an observation image of a cross-section of the toner obtained by cutting a sample in which toner particles are embedded in an epoxy resin or the like with a microtome, an ultramicrotome, or a FIB-STEM.

[0100] The layered inorganic mineral is not particularly limited and can be appropriately selected according to the purpose. For example, smectite group clay minerals (montmorillonite, saponite, hectorite, etc.), kaolin group clay minerals (kaolinite, etc.), bentonite, attapulgite, magadiite, kanemite, etc. can be mentioned. These may be used alone or in combination of two or more.

[0101] The organically modified layered inorganic mineral is not particularly limited and can be appropriately selected according to the purpose. For example, organically modified layered inorganic minerals in which at least a part of the ions existing between the layers of these layered inorganic minerals are modified with organic ions can be mentioned. Among these, those in which at least a part of the ions between the layers of smectite group clay minerals having a basic crystal structure of smectite are modified with organic cations are preferable from the viewpoint of dispersion stability in the vicinity of the toner surface. Those in which at least a part of the ions between the layers of montmorillonite are modified with organic cations and those in which at least a part of the ions between the layers of bentonite are modified with organic cations are Particularly preferred.

[0102] The fact that at least a part of the ions existing between the layers of the layered inorganic mineral in the organically modified layered inorganic mineral is modified with organic ions can be confirmed by gas chromatography-mass spectrometry (GCMS). For example, a solution in which the binder resin in the toner as a sample is dissolved with a solvent is filtered, the obtained solid is thermally decomposed with a thermal decomposition device, and a method of identifying the structure of the organic substance with GCMS is preferably mentioned. Specifically, as the thermal decomposition device, Py-2020D (manufactured by Frontier Lab) is used, thermal decomposition is performed at 550 °C, and then identification is performed with a GCMS device QP5000 (manufactured by Shimadzu Corporation).

[0103] In addition, examples of the organically modified layered inorganic mineral include a layered inorganic compound in which part of the divalent metal of the layered inorganic mineral is replaced with a trivalent metal to introduce a metal anion, and at least part of the metal anion is modified with an organic anion. Commercially available products can be used as the organically modified layered inorganic mineral. Examples of such commercially available products include quaternary ammonium 18 bentonites such as Bentone 3, Bentone 38, Bentone 38V (all manufactured by Elementis Specialties), Thixogel VP (manufactured by United catalyst), Claytone 34, Claytone 40, Claytone XL (all manufactured by Southern Clay); stearalkonium bentonites such as Bentone 27 (manufactured by Rheox), Thixogel LG (manufactured by BYK Additives & Instruments), Claytone AF, Claytone APA (both manufactured by BYK Additives & Instruments); quaternary ammonium 18 / benzalkonium bentonites such as Claytone HT, Claytone PS (both manufactured by Southern Clay); organically modified montmorillonites such as Claytone HY (manufactured by Southern Clay); organically modified saponites such as Lucentite SPN (manufactured by Coop Chemical), etc. Among these, Claytone AF and Claytone APA are particularly preferred.

[0104] In addition, as the organically modified layered inorganic mineral, those obtained by modifying DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.) with a compound having the organic ion represented by R1(OR2)nOSO3M (wherein R1 represents an alkyl group having 13 carbon atoms, R2 represents an alkylene group having 2 to 6 carbon atoms, n represents an integer of 2 to 10, and M represents a monovalent metal element) are particularly preferred. Examples of the compound having the organic ion represented by R1(OR2)nOSO3M include, for example, Hytenol 330T (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0105] The organic-modified layered inorganic mineral may be used as a masterbatch that is mixed with a resin and compounded. There are no particular restrictions on the resin, and it can be appropriately selected from known ones according to the purpose.

[0106] As the content of the organic-modified layered inorganic mineral in the toner, 0.1% by mass to 3.0% by mass is preferable, and 0.3% by mass to 1.5% by mass is particularly preferable. When the content is less than 0.1% by mass, it is difficult to exhibit the effect of the layered inorganic mineral, and when it exceeds 3.0% by mass, there is a tendency to inhibit low-temperature fixability.

[0107] The organic ion modifier, which has the organic ions and is a compound capable of modifying at least a part of the ions present between the layers of the layered inorganic mineral into organic ions, is not particularly limited and can be appropriately selected according to the purpose. For example, quaternary alkylammonium salts, phosphonium salts, imidazolium salts; sulfates having skeletons such as branched, unbranched or cyclic alkyls with 1 to 44 carbon atoms, branched, unbranched or cyclic alkenyls with 1 to 22 carbon atoms, branched, unbranched or cyclic alkoxys with 8 to 32 carbon atoms, branched, unbranched or cyclic hydroxyalkyls with 2 to 22 carbon atoms, ethylene oxide, and propylene oxide, sulfonates having the skeleton, carboxylates having the skeleton, phosphates having the skeleton, etc. can be mentioned. Among these, quaternary alkylammonium salts and carboxylic acids having an ethylene oxide skeleton are preferable, and quaternary alkylammonium salts are particularly preferable. These may be used alone or in combination of two or more. Examples of the quaternary alkylammonium include trimethylstearylammonium, dimethylstearylbenzylammonium, dimethyloctadecylammonium, oleylbis(2-hydroxyethyl)methylammonium, etc.

[0108] -Charge control agent- In addition, in order to impart appropriate charging ability to the toner, it is also possible to contain a charge control agent in the toner as necessary. As the charge control agent, any known charge control agent can be used. Since the color tone may change when using a colored material, a material close to colorless or white is preferred. For example, triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, simple substances of phosphorus or their compounds, simple substances of tungsten or their compounds, fluorine-based activators, metal salts of salicylic acid, metal salts of salicylic acid derivatives, etc. can be mentioned. These may be used alone or in combination of two or more.

[0109] The content of the charge control agent is determined by the toner manufacturing method including the type of the binder resin and the dispersion method, and is not uniquely limited. However, 0.01 mass% to 5 mass% is preferred with respect to the binder resin, and 0.02 mass% to 2 mass% is more preferred. When the addition amount exceeds 5 mass%, the chargeability of the toner is too large, the effect of the charge control agent is reduced, the electrostatic attraction to the developing roller increases, which may lead to a decrease in the fluidity of the developer and a decrease in the image density. When it is less than 0.01 mass%, the charge rising property and the charge amount are not sufficient, and it may easily affect the toner image.

[0110] <<External additive>> There is no particular limitation on the external additive, and it can be appropriately selected from known ones according to the purpose. For example, silica fine particles, hydrophobized silica fine particles, fatty acid metal salts (such as zinc stearate, aluminum stearate, etc.); metal oxides (such as titania, alumina, tin oxide, antimony oxide, etc.) or their hydrophobized products, fluoropolymers, etc. can be mentioned. Among these, hydrophobized silica fine particles, titania particles, hydrophobized titania fine particles, are preferably mentioned.

[0111] Examples of the hydrophobized silica fine particles include HDK H2000T, HDK H2000 / 4, HDK H2050EP, HVK21, HDK H1303VP (all manufactured by Clariant Japan); R972, R974, RX200, RY200, R202, R805, R812, NX90G (all manufactured by Nippon Aerosil Co., Ltd.).

[0112] Examples of the titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.); STT-30, STT-65C-S (both manufactured by Titanium Industry Co., Ltd.); TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.); MT-150W, MT-500B, MT-600B, MT-150A (all manufactured by Teika Corporation).

[0113] Examples of the hydrophobized titanium oxide fine particles include T-805 (manufactured by Nippon Aerosil Co., Ltd.); STT-30A, STT-65S-S (both manufactured by Titanium Industry Co., Ltd.); TAF-500T, TAF-1500T (both manufactured by Fuji Titanium Industry Co., Ltd.); MT-100S, MT-100T (both manufactured by Teika Corporation); IT-S (manufactured by Ishihara Sangyo Co., Ltd.).

[0114] The content of the external additive is not particularly limited and can be appropriately selected according to the purpose. However, it is preferably 0.3 to 3.0 parts by mass, more preferably 0.5 to 2.0 parts by mass, based on 100 parts by mass of the toner base particles.

[0115] The total coating rate of the external additive with respect to the toner base particles is not particularly limited, but is preferably 50% to 90%, more preferably 60% to 80%.

[0116] <Method for manufacturing toner> In the present invention, any known toner manufacturing method and materials can be used as long as the conditions are satisfied, and there is no particular limitation. For example, there are a kneading and grinding method and a so-called chemical method in which toner particles are granulated in an aqueous medium.

[0117] Examples of the chemical method include suspension polymerization, emulsion polymerization, seed polymerization, dispersion polymerization, etc. that produce using monomers as starting materials; the solution suspension method that dissolves a resin or resin precursor in an organic solvent or the like and disperses or emulsifies it in an aqueous medium; in the solution suspension method, an oil phase composition containing a resin precursor having a functional group capable of reacting with an active hydrogen group (reactive group-containing prepolymer) is emulsified or dispersed in an aqueous medium containing resin fine particles, and in the aqueous medium, an active hydrogen group-containing compound and the reactive group-containing prepolymer are reacted (ester extension method); the phase inversion emulsification method that adds water to a solution composed of a resin or resin precursor and a suitable emulsifier to cause phase inversion; and these methods Examples include the aggregation method of aggregating the resin particles obtained by these methods in a state of being dispersed in an aqueous medium and granulating them into particles of a desired size by heating and melting or the like. Among these, toners obtained by the solution suspension method, the ester extension method, and the aggregation method are preferable from the viewpoint of granulation properties (control of particle size distribution, control of particle shape, etc.), and the toner obtained by the ester extension method is more preferable. Details of these production methods will be described below.

[0118] The kneading and pulverizing method is, for example, a method of producing the mother particles of the toner by melting and kneading a toner material having at least a colorant, a binder resin, and a release agent, and then pulverizing and classifying it.

[0119] In the melting and kneading, the toner materials are mixed, and the mixture is charged into a melting and kneading machine and melted and kneaded. As the melting and kneading machine, for example, a single-screw or twin-screw continuous kneading machine or a batch kneading machine using a roll mill can be used. For example, the KTK type twin-screw extruder manufactured by Kobe Steel, Ltd., the TEM type extruder manufactured by Toshiba Machine Co., Ltd., the twin-screw extruder manufactured by CKC Co., Ltd., the PCM type twin-screw extruder manufactured by Ikegai Iron Works Co., Ltd., the conical kneader manufactured by Buss Co., Ltd., etc. are preferably used. This melting and kneading is preferably performed under appropriate conditions so as not to cause cleavage of the molecular chains of the binder resin. Specifically, the melting and kneading temperature is determined with reference to the softening point of the binder resin. If it is too high above the softening point, cleavage will be severe, and if it is too low, dispersion may not proceed.

[0120] In the above-mentioned pulverization, the kneaded product obtained in the above-mentioned kneading is pulverized. In this pulverization, it is preferable to first coarsely pulverize the kneaded product and then finely pulverize it. At this time, a method of pulverizing by colliding with a collision plate in a jet air flow, pulverizing by colliding particles with each other in a jet air flow, or pulverizing in a narrow gap between a mechanically rotating rotor and a stator is preferably used.

[0121] The above-mentioned classification classifies the pulverized product obtained in the above-mentioned pulverization and adjusts it to particles of a predetermined particle size. The above-mentioned classification can be performed, for example, by removing fine particle portions using a cyclone, a decanter, a centrifuge, or the like. After the above-mentioned pulverization and classification are completed, the pulverized product can be classified in an air flow by centrifugal force or the like to produce toner base particles of a predetermined particle size.

[0122] The above-mentioned dissolution-suspension method is a method for producing toner base particles, for example, by dispersing or emulsifying an oil-phase composition in which a toner composition containing at least a binder resin or a resin precursor, a colorant, and a release agent is dissolved or dispersed in an organic solvent in an aqueous medium.

[0123] As the organic solvent used when dissolving or dispersing the above-mentioned toner composition, it is preferable that the boiling point is less than 100 °C and volatile, from the viewpoint of facilitating subsequent solvent removal. Examples of the organic solvent include ester-based or ester-ether-based solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, and ethyl cellosolve acetate; ether-based solvents such as diethyl ether, tetrahydrofuran, dioxane, ethyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, and cyclohexanone; alcohol-based solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2-ethylhexyl alcohol, and benzyl alcohol; and mixed solvents of two or more of these.

[0124] In the dissolution-suspension method, when dispersing or emulsifying the oil-phase composition in an aqueous medium, an emulsifier or a dispersant may be used as necessary. As the emulsifier or dispersant, known surfactants, water-soluble polymers, etc. can be used. There is no particular limitation on the surfactant, and examples thereof include anionic surfactants (such as alkylbenzene sulfonic acid and phosphate esters), cationic surfactants (such as quaternary ammonium salt type and amine salt type), amphoteric surfactants (such as carboxylate type, sulfate ester salt type, sulfonate type, and phosphate ester salt type), and nonionic surfactants (such as AO addition type and polyhydric alcohol type). The surfactant may be used alone or in combination of two or more surfactants.

[0125] Examples of the water-soluble polymer include cellulose-based compounds (such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, and saponified products thereof), gelatin, starch, dextrin, gum arabic, chitin, chitosan, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyethyleneimine, polyacrylamide, polymers containing acrylic acid (salt) (such as sodium polyacrylate, potassium polyacrylate, ammonium polyacrylate, partially neutralized sodium hydroxide product of polyacrylic acid, sodium acrylate-acrylic acid ester copolymer), (partially) neutralized sodium hydroxide product of styrene-maleic anhydride copolymer, water-soluble polyurethane (reaction product of polyethylene glycol, polycaprolactone diol, etc. and polyisocyanate), etc. Also, as an auxiliary agent for emulsification or dispersion, the above-mentioned organic solvents and plasticizers, etc. can be used in combination. can be used.

[0126] The toner according to the present invention is preferably obtained by granulating mother particles of the toner by a method (ester extension method) in which, in a dissolution suspension method, an oil phase composition containing at least a binder resin, a binder resin precursor having a functional group capable of reacting with an active hydrogen group (reactive group-containing prepolymer), a colorant, and a release agent is dispersed or emulsified in an aqueous medium containing resin fine particles, and the active hydrogen group-containing compound contained in the oil phase composition and / or the aqueous medium is reacted with the reactive group-containing prepolymer.

[0127] The resin fine particles can be formed using known polymerization methods, but it is preferable to obtain them as an aqueous dispersion of the resin fine particles. Examples of methods for preparing an aqueous dispersion of resin fine particles include the methods shown in the following (a) to (h). (a) A method of directly preparing an aqueous dispersion of resin fine particles by a polymerization reaction such as a suspension polymerization method, an emulsion polymerization method, a seed polymerization method, or a dispersion polymerization method using a vinyl monomer as a starting material. (b) A method of preparing an aqueous dispersion of resin fine particles by dispersing a precursor (monomer, oligomer, etc.) of a polyaddition or condensation resin such as a polyester resin, a polyurethane resin, or an epoxy resin or a solvent solution thereof in an aqueous medium in the presence of a suitable dispersant and then heating or adding a curing agent to cure it. (c) A method of preparing an aqueous dispersion of resin fine particles by dissolving a suitable emulsifier in a precursor (monomer, oligomer, etc.) of a polyaddition or condensation resin such as a polyester resin, a polyurethane resin, or an epoxy resin or a solvent solution thereof (preferably liquid and may be liquefied by heating), adding water, and performing phase inversion emulsification. (d) A method of preparing an aqueous dispersion of resin fine particles by pulverizing and classifying a resin synthesized in advance by a polymerization reaction (e.g., addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) using a fine pulverizer such as a mechanical rotation type or a jet type to obtain resin fine particles and then dispersing them in water in the presence of a suitable dispersant. (e) A method for preparing an aqueous dispersion of resin fine particles, which comprises forming resin fine particles by spraying a resin solution prepared by dissolving a resin synthesized in advance by a polymerization reaction (e.g., addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent in a mist form, and then dispersing the resin fine particles in water in the presence of a suitable dispersant. (f) A method for preparing an aqueous dispersion of resin fine particles, which comprises adding a poor solvent to a resin solution prepared by dissolving a resin synthesized in advance by a polymerization reaction (e.g., addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent, or precipitating resin fine particles by cooling a resin solution previously dissolved in a solvent by heating, removing the solvent to form resin fine particles, and then dispersing the resin fine particles in water in the presence of a suitable dispersant. (g) A method for preparing an aqueous dispersion of resin fine particles, which comprises dispersing a resin solution prepared by dissolving a resin synthesized in advance by a polymerization reaction (e.g., addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent in an aqueous medium in the presence of a suitable dispersant, and then removing the solvent by heating, reduced pressure, etc. (h) A method for preparing an aqueous dispersion of resin fine particles, which comprises dissolving a suitable emulsifier in a resin solution prepared by dissolving a resin synthesized in advance by a polymerization reaction (e.g., addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent, adding water to effect phase inversion emulsification.

[0128] The volume average particle diameter of the resin fine particles is preferably 10 nm or more and 300 nm or less, more preferably 30 nm or more and 120 nm or less. When the volume average particle diameter of the resin fine particles is 10 nm or more (especially 30 nm or more) and 300 nm or less (especially 120 nm or less), the particle size distribution of the toner does not deteriorate, which is preferable.

[0129] The solid content concentration of the oil phase is preferably about 40 to 80%. If the concentration is too high, dissolution or dispersion becomes difficult, and the viscosity becomes high, making it difficult to handle. If the concentration is too low, the productivity of the toner decreases.

[0130] The toner compositions other than the binder resin, such as the colorant and the release agent, and the organic modified layered inorganic minerals, and their master batches, etc., may be individually dissolved or dispersed in an organic solvent and then mixed with the binder resin solution or dispersion.

[0131] As the aqueous medium, water alone may be used, or a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohols (such as methanol, isopropanol, and ethylene glycol), dimethylformamide, tetrahydrofuran, cellosolves (such as methyl cellosolve), and lower ketones (such as acetone and methyl ethyl ketone).

[0132] The method of dispersing or emulsifying into the aqueous medium is not particularly limited, and known equipment such as low-speed shearing type, high-speed shearing type, friction type, high-pressure jet type, and ultrasonic wave can be applied. Among them, from the viewpoint of reducing the particle size, the high-speed shearing type is preferable. When using a high-speed shearing type disperser, the rotation speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The temperature during dispersion is usually 0 to 150 °C (under pressure), preferably 20 to 80 °C.

[0133] In order to remove the organic solvent from the obtained emulsion dispersion, there is no particular limitation, and known methods can be used. For example, the temperature of the whole system can be gradually increased while stirring under normal pressure or reduced pressure, and the method of completely evaporating and removing the organic solvent in the droplets can be adopted.

[0134] As a method for washing and drying the mother particles of toner dispersed in an aqueous medium, known techniques are used. That is, after solid-liquid separation using a centrifuge, a filter press, etc., the obtained toner cake is redispersed in ion-exchanged water at room temperature to about 40 °C, and after adjusting the pH with an acid or an alkali as necessary, the step of performing solid-liquid separation again is repeated several times to remove impurities, surfactants, etc., and then the toner powder is obtained by drying with an air current dryer, a circulation dryer, a vacuum dryer, a vibration fluidized dryer, etc. At this time, the fine particle components of the toner may be removed by centrifugation or the like, and also, after drying, a desired particle size distribution can be obtained using a known classifier as necessary.

[0135] In the agglomeration method, for example, it is a method of producing toner mother particles by mixing and agglomerating at least a resin fine particle dispersion liquid composed of a binder resin, a colorant particle dispersion liquid, and, if necessary, a release agent particle dispersion liquid. The resin fine particle dispersion liquid is obtained by a known method, for example, emulsion polymerization, seed polymerization, phase inversion emulsification method, etc., and the colorant particle dispersion liquid and the release agent particle dispersion liquid are obtained by dispersing a colorant and a release agent in an aqueous medium by a known wet dispersion method or the like.

[0136] For controlling the agglomerated state, methods such as applying heat, adding a metal salt, and adjusting the pH are preferably used. There is no particular limitation on the metal salt, and examples include monovalent metals constituting salts such as sodium and potassium; divalent metals constituting salts such as calcium and magnesium; trivalent metals constituting salts such as aluminum, etc. Examples of the anion constituting the salt include chloride ion, bromide ion, iodide ion, carbonate ion, sulfate ion, and among these, magnesium chloride, aluminum chloride, and their complexes and multimers are preferable. Also, by heating during or after the agglomeration, the fusion of resin fine particles can be promoted, which is preferable from the viewpoint of the uniformity of the toner. Furthermore, the shape of the toner can be controlled by heating, and usually, the more heating is performed, the closer the toner becomes to a spherical shape.

[0137] As a method for cleaning and drying the toner base particles dispersed in an aqueous medium, the methods described above or the like can be used.

[0138] Also, in order to enhance the fluidity, storage stability, developability, and transferability of the toner, inorganic fine particles such as hydrophobic silica fine powder may be added to and mixed with the toner base particles manufactured as described above. For mixing the additive, a general powder mixer is used, and it is preferable to be equipped with a jacket or the like so that the internal temperature can be adjusted. In order to change the history of the load applied to the additive, the additive may be added halfway or gradually. In this case, the rotation speed, rolling speed, time, temperature, etc. of the mixer may be changed. Alternatively, a strong load may be applied first, followed by a relatively weak load, or vice versa. Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Lodige mixer, a Nauta mixer, a Henschel mixer, and the like. Next, the toner is obtained by passing through a sieve of 250 mesh or more to remove coarse particles and agglomerated particles.

[0139] (Developer) The developer of the present invention comprises at least the above toner and appropriately selected other components such as a carrier. The developer may be a one-component developer or a two-component developer. However, when used in a high-speed printer or the like corresponding to the recent improvement in information processing speed, the two-component developer is preferable in terms of improving the service life and the like.

[0140] In the case of the one-component developer using the above toner, toner aggregates are less likely to be formed over time even with respect to stress by developing means, etc., and there is no toner filming on the developing roller as a developer carrier or toner fusion on a layer thickness regulating member such as a blade for thinning the toner layer. By maintaining good image density stability and transferability, good and stable image quality can be obtained. Also, in the case of the two-component developer using the above toner, toner aggregates are less likely to be formed over time even with respect to agitation stress by developing means, etc., the occurrence of abnormal images is suppressed, and by maintaining good image density stability and transferability, good and stable image quality can be obtained.

[0141] <Carrier> The carrier is not particularly limited and can be appropriately selected according to the purpose. However, those having a core particle and a resin layer (coating layer) that coats the core particle are preferred.

[0142] <<Core particle>> The core particle is not particularly limited as long as it is a magnetic core particle and can be appropriately selected according to the purpose. For example, ferromagnetic metals such as iron and cobalt; iron oxides such as magnetite, hematite, and ferrite; resin particles in which magnetic materials such as various alloys and compounds are dispersed in a resin, and the like can be mentioned. Among these, from the viewpoint of environmental considerations, Mn-based ferrite, Mn-Mg-based ferrite, Mn-Mg-Sr-based ferrite, etc. are preferred.

[0143] - Weight average particle diameter Dw of the core particle - The weight average particle diameter Dw of the core particle refers to the particle diameter at 50% of the integrated value in the particle size distribution of the core particle determined by the laser diffraction or scattering method. The weight average particle diameter Dw of the core particle is not particularly limited and can be appropriately selected according to the purpose. However, 10 μm to 80 μm is preferred, and 20 μm to 65 μm is more preferred.

[0144] The measurement of the weight average particle diameter Dw of the core particle is carried out by measuring the particle size distribution (relationship between the number frequency and the particle diameter) of the particles measured on a number basis using a Microtrac particle size distribution analyzer (HRA9320-X100, manufactured by Honeywell) under the conditions described below, and calculating using the following formula (I). Each channel represents the length for dividing the particle size range in the particle size distribution diagram into measurement width units, and the representative particle diameter adopts the lower limit value of the particle diameter stored in each channel.

[0145] Dw = {1 / Σ(nD 3 )} × {Σ(nD 4 )} ···(I) However, in the formula (I), D represents the representative particle diameter (μm) of the core particles present in each channel, and n represents the total number of core particles present in each channel.

[0146] [Measurement Conditions] [1] Particle size range: 100 μm to 8 μm [2] Channel length (channel width): 2 μm [3] Number of channels: 46 [4] Refractive index: 2.42 [<Coating Layer>] The coating layer contains at least resin and may contain other components such as fillers as required.

[0147] - Resin - The resin for forming the coating layer of the carrier is not particularly limited and can be appropriately selected according to the purpose. For example, polyolefins (e.g., polyethylene, polypropylene, etc.) and their modified products, polystyrene, acrylic resins, acrylonitrile, vinyl acetate, vinyl alcohol, vinyl chloride, vinyl carbazole, crosslinkable copolymers containing vinyl ether, etc.; silicone resins composed of organosiloxane bonds or their modified products (e.g., modified products with alkyd resins, polyester resins, epoxy resins, polyurethanes, polyimides, etc.); polyamides; polyesters; polyurethanes; polycarbonates; urea resins; melamine resins; benzoguanamine resins; epoxy resins; ionomer resins; polyimide resins, and their derivatives, etc. These can be used alone or in combination of two or more. Among these, silicone resins are preferred.

[0148] The silicone resin is not particularly limited and can be appropriately selected according to the purpose from generally known silicone resins. For example, straight silicone resins composed only of organosiloxane bonds, and silicone resins modified with alkyd, polyester, epoxy, acrylic, urethane, etc. are mentioned.

[0149] Examples of the straight silicone resin include KR271, KR272, KR282, KR252, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2405, SR2406 (manufactured by Toray Dow Corning Silicone Co., Ltd.), etc.

[0150] In addition, specific examples of the modified silicone resin include epoxy-modified product: ES-1001N, acrylic-modified silicone: KR-5208, polyester-modified product: KR-5203, alkyd-modified product: KR-206, urethane-modified product: KR-305 (all of the above are manufactured by Shin-Etsu Chemical Co., Ltd.), epoxy-modified product: SR2115, alkyd-modified product: SR2110 (manufactured by Toray Dow Corning Silicone Co., Ltd.), etc.

[0151] Note that the silicone resin can be used alone, but it is also possible to use crosslinking reactive components, charge amount adjusting components, etc. simultaneously. Examples of the crosslinking reactive components include silane coupling agents. Examples of the silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, octyltrimethoxysilane, aminosilane coupling agent, etc.

[0152] - Filler - The filler is not particularly limited and can be appropriately selected according to the purpose. Examples include conductive fillers, non-conductive fillers, etc. These can be used alone or in combination of two or more. Among these, it is preferable to contain a conductive filler and a non-conductive filler in the coating layer.

[0153] The conductive filler refers to a filler having a powder specific resistance value of 100 Ω·cm or less. The non-conductive filler refers to a filler having a powder specific resistance value exceeding 100 Ω·cm. The measurement of the powder specific resistance value of the filler can be carried out by using a powder resistance measurement system (MCP-PD51, manufactured by Mitsubishi Chemical Analytech Co., Ltd.) and a resistivity meter (4-terminal 4-probe method, Loresta-GP, manufactured by Mitsubishi Chemical Analytech Co., Ltd.) under the conditions of a sample of 1.0 g, an electrode interval of 3 mm, a sample radius of 10.0 mm, and a load of 20 kN.

[0154] -- Conductive Filler -- The conductive filler is not particularly limited and can be appropriately selected according to the purpose. For example, a conductive filler formed by forming tin dioxide or indium oxide as a layer on a substrate such as aluminum oxide, titanium oxide, zinc oxide, barium sulfate, silicon oxide, zirconium oxide, etc.; a conductive filler formed using carbon black, etc. Among these, a conductive filler containing aluminum oxide, titanium oxide, and barium sulfate is preferred.

[0155] --Non-conductive filler-- The non-conductive filler is not particularly limited and can be appropriately selected according to the purpose. For example, non-conductive fillers formed using aluminum oxide, titanium oxide, barium sulfate, zinc oxide, silicon dioxide, zirconium oxide, etc. are mentioned. Among these even, non-conductive fillers containing aluminum oxide, titanium oxide, and barium sulfate are preferred.

[0156] <Method for manufacturing the carrier> The method for manufacturing the carrier is not particularly limited and can be appropriately selected according to the purpose. However, a method of manufacturing by applying a coating layer forming solution containing the resin and the filler to the surface of the core particles using a fluidized bed type coating device is preferred. When applying the coating layer forming solution, the condensation of the resin contained in the coating layer may be promoted, or after applying the coating layer forming solution, the condensation of the resin contained in the coating layer may be promoted.

[0157] The method for condensing the resin is not particularly limited and can be appropriately selected according to the purpose. For example, a method of condensing the resin by applying heat, light, etc. to the coating layer forming solution is mentioned.

[0158] -Weight average particle diameter Dw of the carrier- The weight average particle diameter Dw of the carrier refers to the particle diameter at 50% of the integrated value in the particle size distribution of the core particles determined by the laser diffraction / scattering method. The weight average particle diameter Dw of the carrier is not particularly limited and can be appropriately selected according to the purpose, but is preferably 10 μm to 80 μm, more preferably 20 μm to 65 μm.

[0159] The measurement of the weight average particle diameter Dw of the carrier is carried out by measuring the particle diameter distribution of the particles measured on a number basis (the relationship between the number frequency and the particle diameter) using a Microtrac particle size distribution analyzer (HRA9320-X100, manufactured by Honeywell) under the conditions described below, and calculating using the following formula (II). Each channel represents the length for dividing the particle diameter range in the particle diameter distribution diagram into units of the measurement width, and the representative particle diameter adopts the lower limit value of the particle diameter stored in each channel.

[0160] Dw = {1 / Σ(nD 3 )} × {Σ(nD 4 )} ···(II) However, in the formula (II), D represents the representative particle diameter (μm) of the carrier present in each channel, and n represents the total number of carriers present in each channel.

[0161] [Measurement conditions] [1] Particle diameter range: 100 μm to 8 μm [2] Channel length (channel width): 2 μm [3] Number of channels: 46 [4] Refractive index: 2.42

[0162] When the developer is a two-component developer, the mixing ratio of the toner and the carrier in the two-component developer is preferably such that the mass ratio of the toner to the carrier is 2.0 to 12.0% by mass, more preferably 2.5 to 10.0% by mass.

[0163] (Toner storage unit) The toner storage unit in the present invention refers to a unit having a function of storing toner, which contains the stored toner. Here, examples of the form of the toner storage unit include a toner storage container, a developing device, and a process cartridge. The toner storage container refers to a container that stores toner. The developing device refers to a device having means for storing and developing toner. The process cartridge refers to a unit in which at least an electrostatic latent image carrier (also referred to as an image carrier) and developing means are integrated, which stores toner and is detachable from the image forming apparatus. The process cartridge may further include at least one selected from charging means, exposure means, and cleaning means.

[0164] By mounting the toner storage unit of the present invention on an image forming apparatus to form an image, since image formation is performed using the toner of the present invention, it is possible to suppress toner scattering and enable low-temperature fixing.

[0165] (Image Forming Method and Image Forming Apparatus) The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, a developing step of developing the electrostatic latent image using the toner or developer of the present invention to form a visible image, a transfer step of transferring the visible image onto a recording medium, and a fixing step of fixing the transferred image on the recording medium. Furthermore, it has other steps appropriately selected as necessary, such as a charge removal step, a cleaning step, a recycling step, a control step, etc.

[0166] The image forming apparatus of the present invention includes an electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, a developing means for developing the electrostatic latent image using the toner or developer of the present invention to form a visible image, a transfer means for transferring the visible image onto a recording medium, and a fixing means for fixing the transferred image on the recording medium. Furthermore, it has other means appropriately selected as necessary, such as a charge removal means, a cleaning means, a recycling means, a control means, etc. Details will be described below.

[0167] -Electrostatic Latent Image Forming Step and Electrostatic Latent Image Forming Means- The electrostatic latent image forming step is a step of forming an electrostatic latent image on an electrostatic latent image carrier. The electrostatic latent image carrier (sometimes referred to as an "electrophotographic photoreceptor" or "photoreceptor") is not particularly limited in terms of its material, shape, structure, size, etc., and can be appropriately selected from known ones. Among them, a drum shape is preferably mentioned as the shape, and examples of the material include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPCs) such as polysilane and phthalopolymethine. Among these, an organic photoreceptor (OPC) is preferred in terms of obtaining a higher-definition image.

[0168] The formation of the electrostatic latent image can be carried out, for example, by uniformly charging the surface of the electrostatic latent image carrier and then exposing it imagewise, and can be carried out by an electrostatic latent image forming means. The electrostatic latent image forming means includes, for example, at least a charging means (charger) for uniformly charging the surface of the electrostatic latent image carrier and an exposure means (exposure device) for exposing the surface of the electrostatic latent image carrier imagewise.

[0169] The charging can be carried out, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger. The charger is not particularly limited and can be appropriately selected according to the purpose. Examples include known contact chargers equipped with conductive or semiconductive rolls, brushes, films, rubber blades, etc., and non-contact chargers using corona discharge such as corotrons and scorotrons. The charger is preferably one that is arranged in contact with or in a non-contact state with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by superimposing a DC voltage and an AC voltage. Also, it is preferable that the charger is a charging roller arranged in a non-contact and close proximity to the electrostatic latent image carrier via a gap tape, and the surface of the electrostatic latent image carrier is charged by superimposing a DC voltage and an AC voltage on the charging roller.

[0170] The exposure can be performed, for example, by imagewise exposing the surface of the electrostatic latent image carrier using the exposure device. The exposure device is not particularly limited as long as it can perform imagewise exposure on the surface of the electrostatic latent image carrier charged by the charger, and can be appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be mentioned. In the present invention, a light backside exposure method of performing imagewise exposure from the backside of the electrostatic latent image carrier may be adopted.

[0171] - Development step and development means - The development step is a step of developing the electrostatic latent image using the toner to form a visible image. The formation of the visible image can be performed, for example, by developing the electrostatic latent image using the toner, and can be performed by the development means. The development means preferably includes at least a developing device that houses the toner and can apply the toner to the electrostatic latent image in a contact or non-contact manner. A developing device equipped with a toner-containing container is more preferable.

[0172] The developing device may be a single-color developing device or a multi-color developing device. For example, those having a stirrer that stirs and charges the toner by frictional agitation and a rotatable magnet roller are preferably mentioned. In the developing device, for example, the toner and the carrier are mixed and stirred, and the toner is charged by the friction at that time and held in a standing state on the surface of the rotating magnet roller to form a magnetic brush. Since the magnet roller is disposed near the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrostatic latent image carrier (photoconductor) by an electric attractive force. As a result, the electrostatic latent image is developed by the toner, and a visible image by the toner is formed on the surface of the electrostatic latent image carrier (photoconductor).

[0173] -Transfer process and transfer means- The transfer process is a process of transferring the visible image onto a recording medium. It is preferably carried out in such a manner that an intermediate transfer member is used, the visible image is first transferred onto the intermediate transfer member, and then the visible image is secondarily transferred onto the recording medium. It is more preferable to use two or more colors of toner, preferably full-color toner, and include a first transfer process of transferring the visible image onto the intermediate transfer member to form a composite transfer image, and a second transfer process of transferring the composite transfer image onto the recording medium. The transfer can be carried out, for example, by charging the electrostatic latent image carrier (photoconductor) using a transfer charger to transfer the visible image, and can be carried out by the transfer means. As the transfer means, a mode having a first transfer means for transferring the visible image onto the intermediate transfer member to form a composite transfer image and a second transfer means for transferring the composite transfer image onto the recording medium is preferable. The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members according to the purpose. For example, a transfer belt or the like is preferably used.

[0174] The transfer means (the first transfer means, the second transfer means) preferably has at least a transfer device that peels and charges the visible image formed on the electrostatic latent image carrier (photoconductor) toward the recording medium side. The number of transfer means can be one or two or more. Examples of the transfer device include a corona transfer device by corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, an adhesive transfer device, etc. The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

[0175] -Fixing process and fixing means- The fixing process is a process of fixing the visible image transferred onto the recording medium using a fixing device. It may be carried out every time the visible image is transferred onto the recording medium for each color developer, or may be carried out simultaneously at once in a stacked state for each color developer. The fixing device is not particularly limited and can be appropriately selected according to the purpose, but known heating and pressing means are preferred. Examples of the heating and pressing means include a combination of a heating roller and a pressing roller, a combination of a heating roller, a pressing roller, and an endless belt, etc. It is preferable that the fixing device has a heating member including a heating element, a film in contact with the heating member, and a pressing member that is in pressure contact with the heating member via the film, and the means for heating and fixing by passing a recording medium on which an unfixed image is formed between the film and the pressing member. The heating in the heating and pressing means is usually preferably 80°C to 200°C. In the present invention, according to the purpose, a known optical fuser may be used, for example, together with or instead of the fixing step and the fixing means.

[0176] The charge removal step is a step of applying a charge removal bias to the electrostatic latent image carrier to remove charge, and can be preferably performed by charge removal means. The charge removal means is not particularly limited as long as it can apply a charge removal bias to the electrostatic latent image carrier, and can be appropriately selected from known charge removers. For example, a charge removal lamp etc. are preferably mentioned.

[0177] The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be preferably performed by cleaning means. The cleaning means is not particularly limited as long as it can remove the toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. For example, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, a web cleaner, etc. are preferably mentioned.

[0178] The recycling step is a step of recycling the toner removed by the cleaning step to the developing means, and can be preferably performed by recycling means. The recycling means is not particularly limited, and examples include known conveying means etc. The control step is a step of controlling each of the above steps, and each step can be preferably performed by control means. The control means is not particularly limited as long as it can control the movement of each of the above means, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

[0179] Fig. 5 shows a first example of the image forming apparatus of the present invention. The image forming apparatus 100A includes a photoreceptor drum 10, a charging roller 20, an exposure device 30, a developing device 40, an intermediate transfer belt 50, a cleaning device 60 having a cleaning blade, and a charge removing lamp 70.

[0180] The intermediate transfer belt 50 is an endless belt stretched by three rollers 51 arranged inside, and can move in the direction of the arrow in the figure. A part of the three rollers 51 also functions as a transfer bias roller capable of applying a transfer bias (primary transfer bias) to the intermediate transfer belt 50. Further, a cleaning device 90 having a cleaning blade is arranged in the vicinity of the intermediate transfer belt 50. Furthermore, a transfer roller 80 capable of applying a transfer bias (secondary transfer bias) for transferring the toner image to the transfer paper 95 is arranged to face the intermediate transfer belt 50.

[0181] In addition, around the intermediate transfer belt 50, a corona charging device 58 for charging the toner image transferred to the intermediate transfer belt 50 is arranged between the contact portion of the photoreceptor drum 10 and the intermediate transfer belt 50 and the contact portion of the intermediate transfer belt 50 and the transfer paper 95 with respect to the rotation direction of the intermediate transfer belt 50.

[0182] The developing device 40 includes a developing belt 41, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided side by side around the developing belt 41. Each color developing unit 45 includes a developer storage section 42, a developer supply roller 43, and a developing roller (developer carrier) 44. The developing belt 41 is an endless belt stretched by a plurality of belt rollers and can move in the direction of the arrow in the figure. Further, a part of the developing belt 41 is in contact with the photosensitive drum 10.

[0183] Next, a method of forming an image using the image forming apparatus 100A will be described. First, after uniformly charging the surface of the photosensitive drum 10 using the charging roller 20, exposure light L is applied to the photosensitive drum 10 using the exposure device 30 to form an electrostatic latent image. Next, the electrostatic latent image formed on the photosensitive drum 10 is developed with toner supplied from the developing device 40 to form a toner image. Further, after the toner image formed on the photosensitive drum 10 is transferred (primary transfer) onto the intermediate transfer belt 50 by the transfer bias applied from the roller 51, it is transferred (secondary transfer) onto the transfer paper 95 by the transfer bias applied from the transfer roller 80. On the other hand, the photosensitive drum 10 onto which the toner image has been transferred to the intermediate transfer belt 50 is discharged by the discharge lamp 70 after the toner remaining on the surface has been removed by the cleaning device 60.

[0184] FIG. 6 shows a second example of the image forming apparatus used in the present invention. The image forming apparatus 100B has the same configuration as the image forming apparatus 100A, except that the developing belt 41 is not provided and the black developing unit 45K, the yellow developing unit 45Y, the magenta developing unit 45M, and the cyan developing unit 45C are directly opposed and arranged around the photosensitive drum 10.

[0185] FIG. 7 shows a third example of the image forming apparatus used in the present invention. The image forming apparatus 100C is a tandem type color image forming apparatus and includes a copying machine main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

[0186] The intermediate transfer belt 50 provided at the center of the copying apparatus main body 150 is an endless belt stretched over three rollers 14, 15, and 16, and can move in the direction of the arrow in the figure. Near the roller 15, a cleaning device 17 having a cleaning blade for removing toner remaining on the intermediate transfer belt 50 onto which the toner image has been transferred to the recording paper is disposed. The image forming units 18Y, 18C, 18M, and 18K for yellow, cyan, magenta, and black are juxtaposed along the conveyance direction while facing the intermediate transfer belt 50 stretched by the rollers 14 and 15 to form a tandem type image forming unit 120.

[0187] Also, an exposure device 21 is disposed near the image forming unit 120. Further, a secondary transfer belt 24 is disposed on the side opposite to the side where the image forming unit 120 of the intermediate transfer belt 50 is disposed. The secondary transfer belt 24 is an endless belt stretched over a pair of rollers 23, and the recording paper conveyed on the secondary transfer belt 24 and the intermediate transfer belt 50 can come into contact with each other between the rollers 16 and 23.

[0188] Also, near the secondary transfer belt 24, a fixing device 25 including a fixing belt 26 which is an endless belt stretched over a pair of rollers and a pressure roller 27 disposed in pressure contact with the fixing belt 26 is disposed. A sheet reversing device 28 for reversing the recording paper when forming images on both sides of the recording paper is disposed near the secondary transfer belt 24 and the fixing device 25.

[0189] Next, a method of forming a full-color image using the image forming apparatus 100C will be described. First, place a color document on the document table 130 of the automatic document feeder (ADF) 400, or open the automatic document feeder 400 and place the color document on the contact glass 32 of the scanner 300, and then close the automatic document feeder 400. When the start switch is pressed, if a document is set on the automatic document feeder 400, the document is conveyed and moved onto the contact glass 32. On the other hand, if a document is set on the contact glass 32, the scanner 300 is immediately driven, and the first traveling body 33 equipped with a light source and the second traveling body 34 equipped with a mirror travel. At this time, after the reflected light of the light irradiated from the first traveling body 33 from the document surface is reflected by the second traveling body 34, it is received by the reading sensor 36 through the imaging lens 35, so that the document is read, and image information of black, yellow, magenta, and cyan is obtained.

[0190] The image information of each color is transmitted to the image forming unit 120 of each color, and a toner image of each color is formed. As shown in FIG. 8, each image forming unit 120 of each color includes a photosensitive drum 10, a charging roller 160 for uniformly charging the photosensitive drum 10, an exposure device 21 for exposing the photosensitive drum 10 to exposure light L based on the image information of each color to form an electrostatic latent image of each color, a developing device 61 for developing the electrostatic latent image with a developer of each color to form a toner image of each color, a transfer roller 62 for transferring the toner image onto the intermediate transfer belt 50, a cleaning device 63 having a cleaning blade, and a charge elimination lamp 64.

[0191] The toner images of each color formed by the image forming units 120 of each color are sequentially transferred (primary transfer) onto the intermediate transfer body 50 that moves while being stretched over the rollers 14, 15, and 16, and are superimposed to form a composite toner image.

[0192] On one hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out the recording paper from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143, separate the sheets one by one with the separation roller 145, send them out to the paper feed path 146, convey them with the conveying roller 147, guide them to the paper feed path 148 in the copying machine main body 150, and abut them against the registration roller 49 to stop. Alternatively, the paper feed roller is rotated to feed out the recording paper on the manual feed tray 54, separate the sheets one by one with the separation roller 52, guide them to the manual paper feed path 53, and abut them against the registration roller 49 to stop.

[0193] Note that the registration roller 49 is generally used while being grounded, but it may also be used in a state where a bias is applied to remove the paper dust of the recording paper. Next, by rotating the registration roller 49 in synchronization with the composite toner image formed on the intermediate transfer belt 50, the recording paper is sent out between the intermediate transfer belt 50 and the secondary transfer belt 24, and the composite toner image is transferred (secondary transfer) onto the recording paper. Note that the toner remaining on the intermediate transfer belt 50 onto which the composite toner image has been transferred is removed by the cleaning device 17.

[0194] The recording paper onto which the composite toner image has been transferred is conveyed by the secondary transfer belt 24 and then the composite toner image is fixed by the fixing device 25. Next, the conveyance path of the recording paper is switched by the switching claw 55 and it is discharged onto the paper discharge tray 57 by the paper discharge roller 56. Alternatively, the conveyance path of the recording paper is switched by the switching claw 55, it is reversed by the sheet reversing device 28, an image is similarly formed on the back side, and then it is discharged onto the paper discharge tray 57 by the paper discharge roller 56.

[0195] According to the image forming method and the image forming apparatus of the present invention, a high-quality image can be provided over a long period of time.

[0196] The present invention relates to the cyan toner of the following (1), and includes the following (2) to (8) as embodiments. (1) A cyan toner containing at least a binder resin and a colorant, wherein in the Raman spectroscopy of the cyan toner, 2600 cm-1 ~2800 cm -1 When the intensity of the Raman spectrum of each toner particle at the wavenumber λ at which the total intensity obtained by adding up the Raman spectra of each toner particle obtained in the wavenumber range of is at its maximum is normalized to 1, 2600 cm -1 ~3180 cm -1 the integrated intensity of the spectrum of each toner particle obtained in the wavenumber range of is defined as I n and the average value of the above I n is defined as I ave When the value calculated by the following (Equation 1) is defined as the CH ratio, a cyan toner in which the percentage by number of toner particles having an absolute value of the CH ratio of 7.0% or more is 1.0% by number or more and 20.0% by number or less with respect to all the toner particles. CH ratio (%) = [(I n - I ave ) / I ave × 100 ··· (Equation 1) (2) The cyan toner according to (1) above, wherein the percentage by number of toner particles having an absolute value of the CH ratio of 15.0% or more is 1.0% by number or less. (3) The cyan toner according to (1) or (2) above, wherein the percentage by number of toner particles having an absolute value of the CH ratio of 7.0% or more is 5.0% by number or more and 15.0% by number or less. (4) The cyan toner according to any one of (1) to (3) above, wherein the percentage by number of toner particles having an absolute value of the CH ratio of 15.0% or more is 0.5% by number or less. (5) The cyan toner according to any one of (1) to (4) above, wherein the median value of the CH ratio is -2.0% or more. (6) A developer containing the cyan toner according to any one of (1) to (5) above. (7) A toner container unit containing the cyan toner according to any one of (1) to (5) above. (8) An electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for developing the electrostatic latent image to form a visible image using the cyan toner according to any one of (1) to (5) above or the developer according to (6) above, Transfer means for transferring the visible image onto a recording medium, An image forming apparatus having fixing means for fixing the transferred image on the recording medium. (9) An electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, A developing step of developing the electrostatic latent image using the cyan toner according to any one of the above (1) to (5) or the developer according to the above (6) to form a visible image, A transfer step of transferring the visible image onto a recording medium, An image forming method having a fixing step of fixing the transferred image on the recording medium.

Example

[0197] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples. In the description of the examples, [%] indicates mass%, and "parts" indicates "parts by mass".

[0198] (Example 1) <Manufacture of Toner 1> -Synthesis of polyester resin- Reaction 1: In a reaction vessel equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple, bisphenol A ethylene oxide 3 mol adduct (EO) and 1,2-propylene glycol (PG) were charged at a molar ratio of 90 / 10, and terephthalic acid (TPA) and adipic acid (APA) were charged at a molar ratio of 70 / 30, with OH / COOH = 1.33, and reacted at 230 °C for 10 hours at normal pressure together with 500 ppm of titanium tetraisopropoxide. Reaction 2: Then, the reaction was carried out for 5 hours under a reduced pressure of 10 mmHg to 15 mmHg. Reaction 3: Then, 10 parts of trimellitic anhydride (TMA) was added to the reaction vessel and reacted at 180 °C and normal pressure for 3 hours to obtain [polyester resin].

[0199] -Synthesis of prepolymer- Into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-molar adduct, 81 parts of bisphenol A propylene oxide 2-molar adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride, and 2 parts of dibutyltin oxide were added. The reaction was carried out at 230 °C for 8 hours under normal pressure, and then at a reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain an [intermediate polyester resin]. The obtained [intermediate polyester resin] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a glass transition temperature (Tg) of 55 °C, an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g. Next, into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, 410 parts of the [intermediate polyester resin], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate were added and reacted at 100 °C for 5 hours to obtain a [prepolymer]. The free isocyanate % of the obtained [prepolymer] was 1.53%.

[0200] - Preparation of release agent dispersion - Into a container equipped with a stirrer bar and a thermometer, 70 parts of carnauba wax (WA-05, manufactured by Noda Ceramica Co., Ltd.), 140 parts of [polyester resin], and 290 parts of ethyl acetate were added. The temperature was raised to 75 °C under stirring and held at 75 °C for 1.5 hours, and then cooled to 30 °C in 1 hour. Using a bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.), dispersion was carried out under the conditions of a liquid feeding rate of 5 kg / hr, a disk peripheral speed of 6 m / sec, 80% by volume filling of 0.5 mm zirconia beads, and 3 passes to obtain a [release agent dispersion].

[0201] - Preparation of masterbatch - 1,000 parts of water, 1,000 parts of C.I Pigment Blue 15:3, and 1,000 parts of [polyester resin] were added and mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). The mixture was kneaded at 150 °C for 30 minutes using two rolls, then rolled and cooled and pulverized with a pelletizer to obtain [masterbatch 1].

[0202] - Preparation of oil phase 1 - Into a container equipped with a thermometer and a stirrer, 72 parts of [polyester resin], 113 parts of [release agent dispersion], 68 parts of [masterbatch 1], and 122 parts of ethyl acetate were put, and after dispersing them using a shear disperser (TK homomixer) under the condition of a peripheral speed of 12.5 m / sec, using a bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.), at a liquid feeding rate of 5 kg / hr, a disk peripheral speed of 6 m / sec, filling 80% by volume with 0.5 mm zirconia beads, and performing dispersion under the condition of 3 passes, [oil phase 1] was obtained.

[0203] -Manufacture of aqueous dispersion of resin fine particles- Into a reaction vessel equipped with a stirrer bar and a thermometer, 600 parts of water, 120 parts of styrene, 100 parts of methacrylic acid, 45 parts of butyl acrylate, 10 parts of sodium alkyl allyl sulfosuccinate (Eleminol JS-2, manufactured by Sanyo Chemical Industries, Ltd.), and 1 part of ammonium persulfate were charged and stirred at 400 revolutions per minute for 20 minutes, and a white emulsion was obtained. This emulsion was heated to raise the temperature inside the system to 75 °C and reacted for 6 hours. Further, 30 parts of a 1% aqueous ammonium persulfate solution was added and aged at 75 °C for 6 hours to obtain [aqueous dispersion of resin fine particles]. The volume average particle diameter of the particles contained in this [aqueous dispersion of resin fine particles] was 60 nm, the weight average molecular weight of the resin component was 140,000, and the Tg was 73 °C.

[0204] -Preparation of aqueous phase- 990 parts of water, 83 parts of [aqueous dispersion of resin fine particles], 37 parts of a 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), and 90 parts of ethyl acetate were mixed and stirred to obtain [aqueous phase].

[0205] -Emulsification or dispersion- To 374 parts of the aforesaid [oil phase 1], 77 parts of an ethyl acetate solution of [prepolymer] and 2.5 parts of a 50% ethyl acetate solution of isophoronediamine were added, and the mixture was stirred at 5,000 rpm using a TK type homomixer (manufactured by Tokushu Kika Co., Ltd.) to be uniformly dissolved and dispersed, thereby obtaining [oil phase 1']. Next, 550 parts of [aqueous phase] were placed in another container equipped with a stirrer and a thermometer, and while stirring at 11,000 rpm using a TK type homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), [oil phase 1'] was added and emulsified for 1 minute to obtain [emulsion slurry 1].

[0206] -Desolventization ~ Washing ~ Drying- Into a container equipped with a stirrer and a thermometer, [emulsion slurry 1] was charged, and desolventization was carried out at 30°C for 8 hours under reduced pressure to obtain [slurry 1]. After holding the obtained [slurry 1] at 45°C for 2 hours, it was filtered under reduced pressure, and the following washing treatment was performed. (1) 100 parts of ion-exchanged water were added to the filter cake, mixed with a TK homomixer (for 5 minutes at 6,000 rpm), and then filtered. (2) 100 parts of ion-exchanged water were added to the filter cake of (1), mixed with a TK homomixer (for 5 minutes at 6,000 rpm), and then, while stirring, 1% hydrochloric acid was added until the pH reached about 3.3, and stirring was continued for 1 hour in that state and then filtered. (3) 300 parts of ion-exchanged water were added to the filter cake of (2), mixed with a TK homomixer (for 5 minutes at 6,000 rpm), and the operation of filtering was performed twice to obtain filter cake 1.

[0207] The obtained filter cake 1 was dried at 40°C for 48 hours using a circulating air dryer. Thereafter, it was sieved with a 75 μm mesh sieve to produce [toner base particles 1].

[0208] -Mixing- To the aforesaid [toner base particles 1], 1.5 parts of hydrophobic silica (HDK-2000, manufactured by Wacker Chemie AG) were added per 100 parts of the base particles, and the mixture was mixed at a peripheral speed of 33 m / s for 5 minutes using a 20 L Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). The above was air-sieved through a 500 mesh sieve to obtain [toner 1].

[0209] (Example 2) In the preparation of [Oil Phase 1] in Example 1, toner [Toner 2] was prepared in the same manner as in Example 1, except that the disk peripheral speed of the bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) was changed to 8 m / sec.

[0210] (Example 3) In the preparation of [Oil Phase 1] in Example 1, toner [Toner 3] was prepared in the same manner as in Example 1, except that the disk peripheral speed of the bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) was changed to 9 m / sec.

[0211] (Example 4) In the preparation of [Oil Phase 1] in Example 1, toner [Toner 4] was prepared in the same manner as in Example 1, except that the disk peripheral speed of the bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) was changed to 10 m / sec.

[0212] (Example 5) In the preparation of [Oil Phase 1] in Example 4, toner [Toner 5] was prepared in the same manner as in Example 4, except that the peripheral speed of the shear disperser was changed to 13.5 m / sec for pre-dispersion.

[0213] (Example 6) In the preparation of [Oil Phase 1] in Example 5, toner [Toner 6] was prepared in the same manner as in Example 5, except that the bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) was filled with 80% by volume of 0.3 mm zirconia beads.

[0214] (Example 7) -Preparation of Layered Inorganic Mineral Masterbatch- [Polyester resin] 100 parts, montmorillonite compound modified with a quaternary ammonium salt having a benzyl group in at least a part thereof (Clayton APA, manufactured by Southern Clay Products, particle size 500 nm) 100 parts, and ion-exchanged water 50 parts were thoroughly mixed, and kneading was carried out using an open roll type kneader (manufactured by Nidex / Mitsui Mining Co., Ltd.). Kneading was started at 90 °C and then gradually cooled to 50 °C to prepare [layered inorganic mineral masterbatch 1] in which the ratio (mass ratio) of the resin to the layered inorganic mineral is 1:1. In the preparation of [oil phase 1] in Example 6, [toner 7] was prepared in the same manner as in Example 6 except that 1.6 parts out of 72 parts of [polyester resin] were replaced with [layered inorganic mineral masterbatch 1].

[0215] (Example 8) In the preparation of [oil phase 1] in Example 6, [toner 8] was prepared in the same manner as in Example 6 except that 0.8 part out of 72 parts of [polyester resin] was replaced with [layered inorganic mineral masterbatch 1].

[0216] (Example 9) In the preparation of [oil phase 1] in Example 8, [toner 9] was prepared in the same manner as in Example 8 except that the disk peripheral speed of the bead mill (Ultraviscomill, manufactured by Imex) was changed to 12 m / sec.

[0217] (Example 10) In the preparation of [oil phase 1] in Example 9, [toner 10] was prepared in the same manner as in Example 9 except that the bead mill (Ultraviscomill, manufactured by Imex) was filled with 80% by volume of 0.1 mm zirconia beads.

[0218] (Comparative Example 1) In the preparation of [oil phase 1] in Example 5, [toner 11] was prepared in the same manner as in Example 5 except that dispersion using a bead mill (Ultraviscomill, manufactured by Imex) was not carried out.

[0219] (Comparative Example 2) In the preparation of [oil phase 1] in Example 10, [toner 12] was prepared in the same manner as in Example 10, except that the disk peripheral speed of the bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) was changed to 13 m / sec.

[0220] (Comparative Example 3) In the preparation of [oil phase 1] in Example 9, [toner 13] was prepared in the same manner as in Example 9, except that the peripheral speed of the shear disperser was changed to 10.0 m / sec for dispersion.

[0221] (Comparative Example 4) In Comparative Example 1, in addition to hydrophobic silica, 1.5 parts of titanium oxide surface-modified by zinc ion treatment was added to [toner base particles 1], and [toner 14] was prepared in the same manner as in Comparative Example 1, except that it was mixed at a peripheral speed of 33 m / s for 5 minutes using a 20 L Henschel mixer (manufactured by Mitsui Mining Co., Ltd.).

[0222] (Comparative Example 5) In Comparative Example 1, after obtaining [toner base particles 1], [toner 15] was prepared in the same manner as in Comparative Example 1, except that classification was performed using an air classifier "DS5 type" (manufactured by Nippon Pneumatic Mfg. Co., Ltd.).

[0223] (Comparative Example 6) In Comparative Example 1, after adding 300 parts of ion-exchanged water to the filtered cake after washing and mixing it with a TK homomixer (at a rotation speed of 6,000 rpm for 5 minutes), [toner 16] was prepared in the same manner as in Comparative Example 1, except that a spheroidizing heat treatment was performed at 55 °C for 1 hour. The preparation conditions and the like of the toners obtained as described above are shown in Table 1.

[0224]

Table 1

[0225] (Measurement) For the toners obtained in the above Examples and Comparative Examples, the following measurements were performed.

[0226] <CH rate measurement> Using a Raman microscope "XploRA PLUS" (manufactured by Horiba, Ltd.), Raman spectra of 500 to 600 or more particles per toner particle were measured with a laser having an excitation wavelength of 532 nm. The CH ratio was calculated from the Raman spectra, and the ratio of particles with a CH ratio of 7.0% or more, the ratio of particles with a CH ratio of 15.0% or more, and the median value of the CH ratio were determined. The results are shown in Table 2.

[0227] <X-ray fluorescence elemental analysis (XRF)> (Quantification of layered inorganic minerals in toner) Quantification of the amount of the layered inorganic mineral was performed by X-ray fluorescence. As a calibration curve, toner with a predetermined amount of the layered inorganic mineral added to the toner in advance was prepared, and Al contained in the layered inorganic mineral was measured to obtain the calibration curve. For sample preparation, 3 g of the toner obtained after drying, an automatic pressure molding machine (manufactured by Maekawa, model T-BRB-32), a load of 6.0 t, a pressure application time of 60 sec (manufacturer and conditions), were pellet-molded into a diameter of 3 mm and a thickness of 2 mm. Al in the toner was measured by quantitative analysis using an X-ray fluorescence apparatus (ZSX-100e manufactured by Rigaku Corporation), and the content ratio of the layered inorganic mineral was calculated as mass% from the prepared calibration curve. The results are shown in Table 2.

[0228] <Measurement of charge amount distribution> The charge amount (μC / g) of the toner was measured by a blow-off powder charge amount measuring device TB-200 (manufactured by Kyocera), and the charge amount distribution was measured by a charge amount distribution measuring device Easpart Analyzer (manufactured by Hosokawa Micron) for the Q / d distribution (fC / μm). The particle ratio in the positive charge region was calculated as the WST ratio. The results are shown in Table 2.

[0229] <Measurement of particle size distribution> The particle size distribution of the toner was measured using a Coulter Multisizer III (manufactured by Coulter, trade name), and the ratio (Dv / Dn) was determined from the volume-based weight average particle diameter (Dv) and the number average particle diameter (Dn) obtained from the number distribution, with a personal computer (manufactured by IBM) connected and using dedicated analysis software (manufactured by Coulter). The results are shown in Table 2.

[0230] <Measurement of shape distribution> Using a flow-type particle image analyzer FPIA-3000 (manufactured by Sysmex, trade name), the average circularity of 3,000 or more particles was measured, and the percentage of particles with a circularity of 0.850 or less among the measured particles was determined. The results are shown in Table 2.

[0231]

Table 2

[0232] <Preparation of developer> The above [Toner 1] to [Toner 16] in an amount of 5 parts and 95 parts of the carrier described below were mixed using a Turbler Shaker Mixer (manufactured by Shinmaru Enterprises) to obtain Developers 1 to 16. - Preparation of carrier - 100 parts of silicone resin (organostraight silicone) 100 parts of toluene 5 parts of γ-(2-aminoethyl)aminopropyltrimethoxysilane 10 parts of carbon black The above mixture was dispersed using a homomixer for 20 minutes to prepare a coating layer forming liquid. This coating layer forming liquid was coated on the surface of 1,000 parts of spherical magnetite with a particle diameter of 50 μm using a fluidized bed type coating apparatus to obtain a magnetic carrier. Using Developers 1 to 16, the transferability, resistance to in-machine contamination, and cleanability of the image were evaluated by the evaluation method described below.

[0233] [Evaluation of transferability] Using an evaluation machine of a copier (Imagio MP 7501) manufactured by Ricoh Company, Ltd. tuned to a line speed of 162 mm / sec and a transfer time of 40 msec, for the above [Developer 1], a running test was conducted to output a solid pattern of A4 size and a toner adhesion amount of 0.6 mg / cm 2 as a test image. The transfer efficiency in primary transfer and the transfer efficiency in secondary transfer were obtained by the following (Equation 2) and the following (Equation 3), respectively, at the initial stage of the test image and after 100K output. The evaluation criteria are as follows. Primary transfer efficiency (%) = (toner amount transferred onto the intermediate transfer member / toner amount developed on the electrophotographic photoreceptor) × 100 ··· (Equation 2) Secondary transfer efficiency (%) = [(toner amount transferred onto the intermediate transfer member - remaining toner amount on the intermediate transfer member) / toner amount transferred onto the intermediate transfer member] × 100 ··· (Equation 3)

[0234] - Evaluation criteria - The evaluation criteria were calculated by multiplying the primary transfer rate and the secondary transfer rate and evaluated according to the following criteria. Rank: Transfer rate 10: 99.0% or more 9: 98.0% or more and less than 99.0% 8: 96.0% or more and less than 98.0% 7: 94.0% or more and less than 96.0% 6: 92.0% or more and less than 94.0% 5: 90.0% or more and less than 92.0% 4: 88.0% or more and less than 90.0% 3: 86.0% or more and less than 88.0% 2: 84.0% or more and less than 86.0% 1: Less than 84.0%

[0235] [Evaluation of resistance to internal contamination of the machine] The [Developer 1] of the above embodiment was put into a Ricoh digital color imagio Neo C600 refitted machine for evaluation. After continuously outputting 100,000 sheets of an image chart with a 50% image area in monochrome mode, the stains around the printed matter and the fixing and paper discharging parts were visually observed and evaluated by comparing them with a 10-step (R1~R10) step sample. Note that the stains around the printed matter and the fixing and paper discharging parts mean that they are more stained in ascending order of rank. The evaluation of R1 shows that the stains around the fixing part and the printed matter are at an unacceptable level, and it is not at a level that can be adopted as a product.

[0236] [Evaluation of Blade Cleaning Performance] For the blade cleaning performance, a color copier (Ipsio Color8100; manufactured by Ricoh Company, Ltd.) loaded with the above developer and the electrostatic latent image carrier (electrophotographic photoreceptor, photoreceptor) was used. After running 100,000 sheets using 6,000 papers (manufactured by Ricoh Company, Ltd.) at a printing rate of 7% image occupancy, 10 consecutive images with a 50% image occupancy were continuously output at 10°C in an environment of 15% RH, and the 10th image was stopped during development. At this time, the toner on the drum before and after the cleaning blade on the photoreceptor was respectively tape-transferred. The tape transferred to 6,000 papers was subjected to ID measurement using X-Rite eXact (X-Rite), and the cleaning rate was obtained from the ID according to the following (Equation 4). Cleaning Rate [%] =ΔID (Residual Transfer ID - ID after Cleaning) / Residual Transfer ID ···(Equation 4)

[0237] -Evaluation Criteria- Rank: Cleaning Rate 10: 90% or more 9: 80% or more and less than 90% 8: 70% or more and less than 80% 7: 60% or more and less than 70% 6: 50% or more and less than 60% 5: 40% or more and less than 50% 4: 30% or more and less than 40% 3: 20% or more and less than 30% 2: More than 10% and less than 20% 1: Less than 10% Note that 2 is equivalent to the conventional product, and 1 is at a level where it cannot be adopted as a product.

[0238] <Overall Judgment> The evaluation criteria for the overall judgment are as follows. All ranks were added together to obtain the total rank score, and the toner was evaluated in five levels from the total rank score. "☆" means extremely good, "◎" means very good, "○" means good, "△" means equivalent to the conventional product, and "×" means a level where it cannot be used in practice. "☆", "◎", and "○" were regarded as passing, and "△" and "×" were regarded as failing. In addition, for those with a blade cleaning property rank of "1", the overall judgment was set as "×" regardless of the total rank score. Overall Judgment: Total Rank Score ☆☆: 28 or more ☆: 23 - 27 ◎: 19 - 22 ○: 18 △: 17 or less ×: Blade cleaning property rank is 1 The results obtained above are shown in Table 3.

[0239]

Table 3

[0240] As is clear from the evaluation results shown in Table 3, for Examples 1 - 10, the transferability, resistance to in - machine contamination, and cleaning property are all compatible at a high level. On the other hand, for Comparative Examples 1 - 6, any one of the transfer rate, resistance to in - machine contamination, and cleaning property is at a low level, or the result of one of them has a problem in practice.

Explanation of Symbols

[0241] 10 Electrostatic latent image carrier (photoconductor drum) Electrostatic latent image carrier for 10K black Electrostatic latent image carrier for 10Y yellow Electrostatic latent image carrier for 10M magenta Electrostatic latent image carrier for 10C cyan 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer cleaning device 18K, 18Y, 18M, 18C Image forming unit 20 Charging roller 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressing roller 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer storage section 42Y Developer storage section 42M Developer storage section 42C Developer storage section 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Developing roller 44Y Developing roller 44M Developing roller 44C Developing roller 45K Black developing unit 45Y Yellow developing unit 45M Magenta developing unit 45C Cyan developing unit 49 Resist roller 50 Intermediate transfer belt 51 Roller 52 Separation Roller 53 Manual Feeding Path 54 Manual Feeding Tray 55 Switching Claw 56 Discharge Roller 57 Discharge Tray 58 Corona Charging Device 60 Cleaning Device 61 Developing Device 62 Transfer Roller 63 Photoconductor Cleaning Device 64 Static Eliminator Lamp 70 Static Eliminator Lamp 80 Transfer Roller 90 Cleaning Device 95 Transfer Paper 100A, 100B, 100C Image Forming Device 120 Image Forming Unit 130 Original Document Table 142 Paper Feeding Roller 143 Paper Bank 144 Paper Feeding Cassette 145 Separation Roller 146 Paper Feeding Path 147 Conveyor Roller 148 Paper Feeding Path 150 Copier Main Body 160 Charging Device 200 Paper Feeding Table 300 Scanner 400 Automatic Document Feeder (ADF)

Prior Art Documents

Patent Documents

[0242]

Patent Document 1

Patent Document 2

Patent Document 3

Claims

1. A cyan toner containing at least a binder resin and a colorant, wherein the colorant includes a cyan coloring pigment, the cyan coloring pigment is any one of C.I. Pigment Blue 2, 3, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 60, C.I. Vat Blue 6, C.I. Acid Blue 45, a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on a phthalocyanine skeleton, Green 7, and Green 36, the binder resin includes a polyester resin, toner base particles are granulated in an aqueous medium, the average circularity of the toner is 0.950 to 0.980, In the Raman spectroscopy of the cyan toner, at 2600 cm －１ ~2800 cm －１ When the intensity of the Raman spectrum of each toner particle at the wavenumber λ at which the total intensity obtained by adding the Raman spectra of each toner particle in the wavenumber region is maximized is normalized to 1, at 2600 cm －１ ~3180 cm －１ The integrated intensity of the spectrum of each toner particle obtained in the wavenumber region is defined as I ｎ Let the average value of the above I ｎ be I ａｖｅ When the value calculated by the following (Equation 1) is defined as the CH ratio, a cyan toner in which the percentage of the number of toner particles having an absolute value of the CH ratio of 7.0% or more with respect to all toner particles is 1.0% by number or more and 20.0% by number or less. CH rate (%) = [(I ｎ - I ａｖｅ ) / I ａｖｅ × 100... (Equation 1)

2. The cyan toner according to claim 1, wherein the number ratio of toner particles having an absolute value of the CH rate of 15.0% or more to all toner particles is 1.0% by number or less.

3. The cyan toner according to claim 1 or 2, wherein the volume-based weight average particle diameter (Dv) of the cyan toner is 3 μm to 7 μm, and the ratio (Dv / Dn) of the volume-based weight average particle diameter (Dv) to the number average particle diameter (Dn) of the cyan toner is 1.00 to 1.

25.

4. The cyan toner according to any one of claims 1 to 3, wherein the number ratio of toner particles having an absolute value of the CH rate of 15.0% or more to all toner particles is 0.5% by number or less.

5. The cyan toner according to any one of claims 1 to 4, wherein the median value of the CH rate is -2.0% or more.

6. A toner container unit containing a developer containing the cyan toner according to any one of claims 1 to 5.

7. An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for developing the electrostatic latent image to form a visible image using the cyan toner according to any one of claims 1 to 5, transfer means for transferring the visible image onto a recording medium, An image forming apparatus having fixing means for fixing the transferred image on the recording medium.

8. An electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, a developing step of developing the electrostatic latent image to form a visible image using the cyan toner according to any one of claims 1 to 5, a transfer step of transferring the visible image onto a recording medium, An image forming method having a fixing step of fixing the transferred image on the recording medium.

9. A method for manufacturing a cyan toner containing at least a binder resin and a colorant, A masterbatch preparation step of kneading a mixture of the colorant and the binder resin with a shear disperser; A step of preparing an oil phase by dispersing the masterbatch and the binder resin in a solvent with a mill and a shear disperser; A step of granulating toner base particles in an aqueous medium; A step of externally adding an external additive to the toner base particles, and includes: The colorant includes a cyan coloring pigment; The cyan coloring pigment is any one of C.I. Pigment Blue 2, 3, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 60, C.I. Vat Blue 6, C.I. Acid Blue 45, a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted in a phthalocyanine skeleton, Green 7, and Green 36; The binder resin includes a polyester resin; The average circularity of the toner is 0.950 to 0.

980. In the Raman spectroscopy of the cyan toner, at 2600 cm －１ to 2800 cm －１ When the intensity of the Raman spectrum of each toner particle at the wave number λ at which the total intensity obtained by adding the Raman spectra of each toner particle in the wave number region shows the maximum value is normalized to 1, at 2600 cm －１ to 3180 cm －１ The integrated intensity of the spectrum of each toner particle obtained in the wave number region is I ｎ and the average value of the I ｎ is I ａｖｅ When the value calculated by the following (Formula 1) is defined as the CH ratio, a method for producing a cyan toner in which the number ratio of toner particles having an absolute value of the CH ratio of 7.0% or more to all toner particles is 1.0% by number or more and 20.0% by number or less. CH rate (%) = [(I ｎ - I ａｖｅ ) / I ａｖｅ × 100... (Equation 1)

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