Toner

Abstract

The present invention relates to a toner. A toner comprising toner particles, the toner particles comprising a binder resin comprising a polyester resin and a polyolefin-based resin having a sulfonic acid group, wherein the polyolefin-based resin having a sulfonic acid group is a polymer in which a vinyl-based polymer is bonded to a polyolefin, the content ratio of monomer units containing a sulfonic acid group in the vinyl-based polymer is 1.0% to 20.0% by mass, and in an FT-IR spectrum obtained by measuring a large-particle toner and a small-particle toner obtained by dividing the toner into two approximately equal parts based on the number of particles, a sulfonic acid group at 1130 cm ‑1 to 1170cm ‑1 The intensity of the maximum absorption peak in the range of 1713 cm ‑1 to 1723cm ‑1 The ratio of the intensities of the maximum absorption peaks within a range shows a specific relationship.

Description

Technical Field

[0001] The present invention relates to toners for electrophotographic systems, electrostatic recording systems and electrostatic printing systems. Background Art

[0002] In recent years, with the increasing use of full-color electrophotographic copiers, there is a growing demand not only for higher speeds and higher image quality, but also for further stabilization of image density. To enhance dot reproducibility, toners with smaller particle sizes are required as a specific measure to improve image quality.

[0003] Therefore, Japanese Patent Application Publication No. 2013-088686 proposes a toner with a small particle size and a sharp particle size distribution to improve dot reproducibility. Japanese Patent Application Publication No. 2006-145800 proposes a toner in which the coverage of silica fine particles is adjusted for each particle size range to improve the charging performance and yield of a toner exhibiting variations in particle size distribution. Furthermore, Japanese Patent Application Publication No. 2002-351148 proposes a toner in which a resin containing a sulfonic acid group is added as a charge control agent to improve the toner's charging performance. Summary of the Invention

[0004] The small-particle toner disclosed in Japanese Patent Application Publication No. 2013-088686 provides good image quality in image output under normal temperature and humidity conditions. However, since the coverage of the shell layer and the inorganic fine particles is uniform, the surface charge density is constant and is independent of the particle size. Therefore, as the toner particle size becomes smaller, the surface area decreases, and the charge quantity per toner particle decreases. Under high temperature and high humidity conditions, this phenomenon is more pronounced in toners on the fine powder side of the particle size distribution of small-particle toners. In this case, the charge quantity of the toner is small, and therefore the electric field followability is correspondingly low.

[0005] It has been found that when an attempt is made to transfer from an electrostatic latent image bearing member to an intermediate transfer member or a medium by using an electric field, in some cases, the transferability of the toner sometimes decreases during the transfer process of the electrophotographic system. Furthermore, in the AC development system, the force generated by the pull-back bias from the electrostatic latent image bearing member is weak, so the toner may remain adhered to the electrostatic latent image bearing member, and fogging may occur.

[0006] In the toner disclosed in Japanese Patent Application Laid-Open No. 2006-145800, the coverage of inorganic fine particles is adjusted for each particle size range, so the surface charge density varies with the particle size. However, it has been found that by adjusting the coverage to reduce the charging performance of the toner on the fine powder side, transferability may be reduced and fogging may occur more significantly.

[0007] A sulfonic acid group-containing resin is incorporated into the toner described in Japanese Patent Application Laid-Open No. 2002-351148 to increase the charge capacity under high-temperature, high-humidity conditions. This improves the overall chargeability of the toner, including the fine powder side, and suppresses fogging in the toner. However, the charge capacity under low-temperature, low-humidity conditions tends to increase, with the coarse powder side particularly becoming excessively charged. Consequently, it has been found that in some cases, the electrostatic adhesion between the toner and the developer carrier increases, resulting in a decrease in the developing performance of the electrostatic latent image bearing member and a reduction in image density.

[0008] Under such circumstances, there needs to be a trade-off between good image density and transferability and fog suppression, and therefore there is an urgent need to develop a toner that overcomes the above trade-off and provides excellent image quality. The present disclosure provides a toner having excellent image quality, transferability and image density and suppressing fog.

[0009] The present disclosure relates to a toner comprising toner particles.

[0010] a binder resin comprising a polyester resin, and

[0011] A polyolefin resin having a sulfonic acid group, wherein

[0012] The polyolefin-based resin having a sulfonic acid group is a polymer in which a vinyl-based polymer is bonded to a polyolefin;

[0013] The content ratio of the monomer unit containing a sulfonic acid group in the vinyl polymer is 1.0% by mass to 20.0% by mass; and

[0014] When the toner is classified into two groups, a first group containing toner with a large particle size and a second group containing toner with a small particle size, using a classifier of an inertial classification system so that the number of toner particles in the first group is substantially equal to the number of toner particles in the second group,

[0015] Satisfies expression (1):

[0016] 1.10≤(As / Bs) / (Al / Bl)≤2.00 … (1)

[0017] wherein As represents the sulfonic acid group at 1130 cm-1 attributed to the polyolefin resin in the FT-IR spectrum of the second group obtained by measuring the second group according to the ATR method using Ge as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak within the range;

[0018] Bs represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum of the second group measured by the ATR method using diamond as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak within the range;

[0019] Al represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum obtained by measuring the first group according to the ATR method using Ge as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensities of the maximum absorption peaks within the range of ; and

[0020] B1 represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum obtained by measuring the first group according to the ATR method using diamond as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak in the range.

[0021] The present disclosure can provide a toner having excellent image quality, transferability, and image density and suppressing fogging.Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is an example of a thermal spheroidization treatment device. DETAILED DESCRIPTION

[0023] Unless specifically stated otherwise, expressions indicating a numerical range such as “from XX to YY” and “XX to YY” mean that the numerical range includes the lower limit and the upper limit as endpoints.

[0024] As described above, small particle size toners such as disclosed in Japanese Patent Application Laid-Open No. 2013-088686 show a trade-off between good image density, transferability, and fog suppression, and therefore have room for improvement in image quality, image density, transferability, and fog suppression.

[0025] Therefore, the present inventors have further researched toners that exhibit excellent image quality, image density, transferability, and fog suppression. When toner particle size is reduced to improve image quality, the surface area per toner particle decreases, and the charge amount also decreases. As a result, transferability decreases and fogging occurs.

[0026] In contrast, as conventionally proposed, transferability can be improved and fogging can be suppressed simply by increasing the charge amount of toner; however, the electrostatic latent image is buried with a small amount of toner, which translates into a lower image density.

[0027] The present inventors have further investigated toners that exhibit excellent image quality, image density, transferability, and fog suppression. The present inventors have separately and in detail examined the forces exerted on toners in the electric field between the developer carrier and the electrostatic latent image bearing member. The charge amount of a toner, which influences its dependence on electric field strength, is proportional to its surface area. Therefore, with smaller particle sizes, the charge amount decreases in proportion to the square of the particle size. Conversely, the non-electrostatic adhesive force on the electrostatic latent image bearing member is proportional to the particle size. Therefore, reducing the toner particle size inevitably leads to lower developing performance and the occurrence of fogging.

[0028] Specifically, conventionally proposed methods have been able to improve transferability and suppress fogging simply by increasing the charge amount of a toner in order to increase the electric field flight force within the toner. However, this merely reduces image density stability, and the aforementioned trade-off cannot be overcome. Further research by the present inventors has revealed that the main factors contributing to the reduction in transferability and fogging, as well as the reduction in image density, can be traced back to the different particle sizes in the toner's particle size distribution.

[0029] Specifically, the main factor causing deterioration in transferability and fogging is fine powder, which has a low charge per particle. Meanwhile, the main factor causing a decrease in image density is the charge per mass, which is affected by coarse powder, which has a large mass per particle. Therefore, it has been discovered that this trade-off can be overcome by taking measures to address the charge per particle.

[0030] The toner contains a polyolefin resin having a sulfonic acid group. In a first group containing large-particle toners and a second group containing small-particle toners, obtained by dividing the toners into two roughly equal groups based on the number of toners, the polyolefin resin having a sulfonic acid group is more localized near the surface of the toner particles in the second group than in the first group. As a result, the surface charge density of toners of the same particle size is further increased, and the reduction in transferability and the occurrence of fogging, which are problems associated with a decrease in particle size, can be suppressed. In addition, since the difference in charge between the small-particle toner and the first group is small, image density can be increased.

[0031] That is, the present disclosure relates to a toner containing toner particles containing a binder resin containing a polyester resin, and

[0032] A polyolefin resin having a sulfonic acid group, wherein

[0033] The polyolefin-based resin having a sulfonic acid group is a polymer in which a vinyl-based polymer is bonded to a polyolefin;

[0034] The content ratio of the monomer unit containing a sulfonic acid group in the vinyl polymer is 1.0% by mass to 20.0% by mass; and

[0035] When a classifier using an inertial classification system is used to separate toner into two groups, a first group containing toner with a large particle size and a second group containing toner with a small particle size, so that the number of toner particles in the first group is approximately equal to the number of toner particles in the second group,

[0036] Satisfies expression (1):

[0037] 1.10≤(As / Bs) / (Al / Bl)≤2.00…(1)

[0038] wherein As represents the sulfonic acid group at 1130 cm-1 attributed to the polyolefin resin in the FT-IR spectrum of the second group obtained by measuring the second group according to the ATR method using Ge as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1The ratio of the intensity of the maximum absorption peak within the range;

[0039] Bs represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum of the second group measured by the ATR method using diamond as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak within the range;

[0040] Al represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum obtained by measuring the first group according to the ATR method using Ge as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensities of the maximum absorption peaks within the range of ; and

[0041] B1 represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum obtained by measuring the first group according to the ATR method using diamond as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak in the range.

[0042] The toner includes toner particles containing a polyolefin-based resin having a sulfonic acid group (sulfonic group).

[0043] The polyolefin resin having a sulfonic acid group is a polymer in which a vinyl polymer is bonded to a polyolefin. The vinyl polymer contains a monomer unit having a sulfonic acid group. The content ratio of the monomer unit having a sulfonic acid group in the vinyl polymer is 1.0% to 20.0% by mass.

[0044] By setting the content ratio of the monomer unit having a sulfonic acid group to 1.0% by mass or more, charging performance is maintained also in a high-temperature and high-humidity environment, due to the negative charge derived from the sulfonic acid group.

[0045] By setting the content ratio of the monomer unit having a sulfonic acid group to 20.0% by mass or less, it becomes possible to suppress charge-up in a low-humidity environment and accordingly reduce electrostatic adhesion, improving development performance.

[0046] The content ratio of the monomer unit having a sulfonic acid group in the vinyl polymer is preferably 5.0% by mass to 15.0% by mass, and more preferably 8.0% by mass to 12.0% by mass.

[0047] The content ratio of the monomer unit having a sulfonic acid group in the vinyl polymer is preferably 1 mol% to 12 mol%, more preferably 3 mol% to 12 mol%, still more preferably 6 mol% to 12 mol%, relative to all monomer units constituting the vinyl polymer.

[0048] The term monomeric unit represents the form produced by the reaction of monomeric substances in a polymer. The monomeric unit containing sulfonic acid group is included in the vinyl polymer. Preferably, the monomeric unit in the vinyl polymer is each carbon-carbon bonded portion in the main chain produced by the polymerization of a vinyl monomer of the polymer. For example, a vinyl monomer can be represented by the following formula (A).

[0049]

[0050] (In formula (A), R1 represents a hydrogen atom or an alkyl group (preferably, a C1 to C3 alkyl group, more preferably, a methyl group) and R2 represents an arbitrary substituent.)

[0051] A classifier using an inertial classification system divides the toner particles into roughly equal groups based on particle size: a first group containing large-diameter toner particles and a second group containing small-diameter toner particles. A characteristic feature of the polyolefin-based resin containing monomer units having sulfonic acid groups, which exhibits the aforementioned charging characteristics, is that the particles in the second group (small-diameter toner particles) are more concentrated near the toner surface than those in the first group (large-diameter toner particles).

[0052] Therefore, the charge amount of the second group having a low charge amount per particle can be made relatively high, which in turn allows the charge distribution of the toner to be sharper.

[0053] Specifically, when a classifier using an inertial classification system classifies toner into two groups, i.e., a first group containing toner with a large particle size and a second group containing toner with a small particle size, so that the number of toner particles in the first group is approximately equal to the number of toner particles in the second group, expression (1) is satisfied:

[0054] 1.10≤(As / Bs) / (Al / Bl)≤2.00…(1)

[0055] Wherein As represents the sulfonic acid group at 1130 cm-1 attributed to the polyolefin resin in the FT-IR spectrum of the second group obtained by measuring according to the ATR method using Ge as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak within the range (sulfonic acid group / carbonyl group);

[0056] Bs represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum of the second group measured by the ATR method using diamond as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak within the range;

[0057] Al represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum of the first group measured by the ATR method using Ge as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensities of the maximum absorption peaks within the range of ; and

[0058] B1 represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum of the first group obtained by measuring the spectrum according to the ATR method using diamond as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak in the range.

[0059] Herein, As (measurement of the second group in the colorant) and Al (measurement of the first group in the colorant) are indices regarding the abundance ratio of the polyolefin-based resin having a sulfonic acid group relative to the polyester resin at approximately 0.3 μm from the toner surface in the depth direction of the toner, that is, in the direction from the toner surface toward the center portion of the toner.

[0060] Meanwhile, Bs and Bl are indices regarding the abundance ratio of the polyolefin-based resin having a sulfonic acid group to the polyester resin at about 1.0 μm from the toner surface in the depth direction.

[0061] Assuming that As / Bs is a coefficient regarding the ratio of the composition distribution with respect to the depth direction from the toner surface, a value of the coefficient greater than 1.00 indicates that the polyolefin-based resin having a sulfonic acid group is more concentrated near the surface.

[0062] Therefore, the ratio of As / Bs in the second group of toners relative to Al / Bl in the first group of toners is a value of 1.10 or more, which herein indicates that the resin improving the above-mentioned charging performance can become more concentrated near the surface of the toner having a small particle size in the toner group.

[0063] As a result, the charge amount of the second group having a low charge amount per particle can be made relatively high, which in turn allows the charge distribution of the toner to be made narrower.

[0064] On the other hand, by setting the ratio of As / Bs to Al / Bl to 2.00 or less, the charge amount of the toner on the smaller particle size side can be prevented from becoming excessively high, and the charge distribution can be further narrowed.

[0065] The ratio (As / Bs) / (Al / Bl) is preferably in the range of 1.50 to 2.00, and more preferably in the range of 1.60 to 1.90.

[0066] As long as the particle group obtained by dividing into two parts meets the requirements of the present invention, such that the difference between the number of particles in the first group and the number of particles in the second group is 4% or less, a sufficient effect can be achieved. Therefore, the phrase "divided into two substantially equal parts" in the present invention means dividing into two parts so that the difference in the number of particles is 4% or less.

[0067] The calculation method of As, Bs, Al and Bl is as follows.

[0068] First, the toner is divided into two approximately equal groups based on the number of particles using an Elbow-jet classifier of an inertial classification system (manufactured by Nittetsu Mining Co., Ltd.), ie, a first group having a larger particle size and a second group having a smaller particle size.

[0069] To split the toner into two, the feed amount and fine powder classification edge, which are the operating conditions of the elbow-jet, are optimized, and the coarse powder classification edge is minimized, thereby separating the toner into two roughly equal groups, corresponding to a first group with larger particle sizes and a second group with smaller particle sizes. The specific method is described below.

[0070] To set the operating conditions for the Elbow-Jet, first adjust the air volume control valve so that the air volume on the large-particle side and the small-particle side is the same. Then, move the fine powder classification edge to find a position where the difference in the number of particles distributed between the large-particle side and the small-particle side is approximately 8%. Then, fix the fine powder classification edge at this position and finely adjust the air volume control valves on the large-particle side and the small-particle side to divide the first group (the large-particle side) and the second group (the small-particle side) into roughly equal groups based on the number of particles (so that the difference in the number of particles is 4% or less). At this point, for example, the feed rate can be set to 5 kg / hr, and the distance between the wall of the fine powder passage side within the Elbow-Jet and the front end of the fine powder classification edge can be set to 10 to 15 mm.

[0071] Thereafter, the above ratio can be calculated by performing the following ATR measurement on the fractionated first group and second group.

[0072] In the ATR (attenuated total reflection) method, a sample is brought into close contact with a crystal (ATR crystal) with a higher refractive index than the sample. Infrared light is then directed at an angle of incidence equal to or greater than the critical angle. The incident light then undergoes repeated total reflection at the interface between the crystal and the closely attached sample before exiting the crystal. Therefore, rather than being reflected at the interface between the sample and crystal, the infrared light penetrates slightly into the sample before being totally reflected. This penetration depth depends on the wavelength, angle of incidence, and the refractive index of the ATR crystal.

[0073] d p =λ / (2πn1)×[sin 2 θ-(n1 / n2) 2 ] -1 / 2

[0074] d p : Penetration depth

[0075] n1: refractive index of the sample (1.5 in this disclosure)

[0076] n2: The refractive index of the ATR crystal (4.0 for Ge and 2.4 for diamond)

[0077] θ: angle of incidence

[0078] Therefore, by varying the refractive index and incident angle of the ATR crystal, FT-IR spectra at different penetration depths can be obtained. This characteristic is utilized to determine an index regarding the abundance ratio of the polyolefin resin containing sulfonic acid groups near the toner surface. Consequently, the degree of uneven distribution of the polyolefin resin containing sulfonic acid groups in the depth direction of the toner from the toner surface toward the center of the toner can be quantified as an index.

[0079] In the ATR method, Ge (n2 = 4.0) is used as an ATR crystal at 2000 cm -1 In the case of light with a wavelength of λ = 5 μm and an incident angle of 45°, the above expression yields a penetration depth d of approximately 0.3 μm. p On the other hand, in the case where diamond (n2=2.4) is used as the ATR crystal and measured under the condition of an incident angle of 45°, the penetration depth is about 1.0 μm.

[0080] Specifically, in the FT-IR spectrum of the toner which can be obtained by measuring according to the ATR method, using Ge (n2=4.0) as the ATR crystal, and setting the infrared light incident angle to 45°, at 1130 cm -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm -1 to 1723cm -1 The intensities of the maximum absorption peaks in the range of are marked as As (toner in the second group) and Al (toner in the first group).

[0081] In the FT-IR spectrum of the toner which can be obtained by measuring according to the ATR method, using diamond as the ATR crystal, and setting the incident angle of infrared light to 45°, the infrared ray incident angle at 1130 cm -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm -1 to 1723cm -1 The intensities of the maximum absorption peaks in the range of φ are marked as Bs (toner in the second group) and Bl (toner in the first group).

[0082] At 1713cm -1 to 1723cm -1 The maximum absorption peak in the range of φ is derived from the stretching vibration of -CO- which is a carbonyl group in the polyester resin.

[0083] At 1130cm -1 to 1170cm -1The maximum absorption peak in the range of derives from the stretching vibration of the sulfonyl group in the polyolefin resin having a sulfonic acid group. The larger the peak, the higher the surface abundance ratio of the polyolefin resin.

[0084] The detailed process of the ATR method will be further described.

[0085] Herein, As is preferably 0.10 to 0.40, more preferably 0.20 to 0.40. Furthermore, Bs is preferably 0.10 to 0.30, more preferably 0.10 to 0.20. Furthermore, Al is preferably 0.10 to 0.30, more preferably 0.10 to 0.20. Furthermore, Bl is preferably 0.10 to 0.30, more preferably 0.10 to 0.20.

[0086] The As / Bs ratio is preferably from 1.10 to 2.20, more preferably from 1.50 to 2.10. The Al / Bl ratio is preferably from 0.50 to 1.50, more preferably from 0.80 to 1.10.

[0087] Methods such as those described below can be exemplified as methods of causing the polyolefin-based resin having a sulfonic acid group to be present in the vicinity of the surface of the particles in the second group (small particle size toner) to a greater extent than in the vicinity of the surface of the particles in the first group (large particle size toner). For example, such methods may involve varying the amount of polyolefin-based resin added between the large particle size toner and the small particle size toner to impart charge retention, or may involve varying the abundance ratio of the surface layer between the large particle size toner and the small particle size toner in the core-shell formation step.

[0088] Chemical toner production methods, such as emulsion aggregation, can be used as the core-shell formation step. Alternatively, a dry thermal spheroidization method can be employed, which relies on spontaneous shell formation due to heat treatment as described below. In this dry thermal spheroidization method, the spontaneous shell formation due to heat treatment allows the polyolefin resin to be concentrated near the surface, shortening the diffusion distance as the toner particle size decreases. Consequently, a toner meeting the aforementioned requirements can be readily obtained without the need to mix toners produced according to different formulations.

[0089] The number-based median diameter D50 of the toner is preferably 3.0 μm to 6.0 μm. The span value representing the particle size distribution of the toner obtained according to the following expression (2) is preferably 0.7 to 2.0.

[0090] Span value = (D90-D10) / D50 (2)

[0091] In expression (2), D90 is the particle size of the toner when the cumulative number of particles starting from the smaller particle size is 90%, and D10 is the particle size of the toner when the cumulative number of particles starting from the smaller particle size is 10%.

[0092] A D50 of 3.0 μm or greater improves transferability and suppresses fogging. Simultaneously, a D50 of 6.0 μm or less improves image quality. A span value of 0.7 or greater significantly enhances these effects. Furthermore, a span value of 2.0 or less improves transferability and suppresses fogging.

[0093] More preferably, D50 is 3.0 μm to 5.5 μm, and even more preferably 3.0 μm to 5.0 μm. Thus, better dot reproducibility is achieved and excellent image quality is obtained. More preferably, the span value is 1.1 to 2.0. Herein, D10, D50, and D90 are measured using a particle size distribution analyzer (Coulter Multisizer III: manufactured by Beckman Coulter, Inc.) according to the Coulter method. Details are further described.

[0094] The D10, D50, and D90 of the toner were calculated by performing measurement with 25,000 effective measurement channels based on the pore resistance method and using a precision particle size distribution measuring apparatus "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.) equipped with an orifice tube having an aperture size of 100 μm and dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.) for setting measurement conditions and performing measurement data analysis, and analyzing the measurement data.

[0095] A solution prepared by dissolving special grade sodium chloride in deionized water to a concentration of about 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter, Inc.), can be used as the aqueous electrolytic solution for measurement.

[0096] Before measurement and analysis, set up the dedicated software as follows.

[0097] In the "Change Standard Measurement Method (SOM) Screen" of the dedicated software, set the total count of the control mode to 50,000 particles, the number of measurements to 1, and the value obtained using "Standard Particles 10.0 μm (manufactured by Beckman Coulter, Inc.)" as the Kd value. By pressing the measurement button for threshold / noise level, the threshold and noise level are automatically set. In addition, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flushing of the mouth tube after measurement."

[0098] In the "Pulse to Particle Size Conversion Setting Interface" of the dedicated software, the element interval was set to logarithmic particle size, the particle size element was set to 256 particle size elements, and the particle size range was set to 2 μm to 60 μm.

[0099] Specific measurement methods are described in (1) to (7) below.

[0100] (1) Place approximately 200 mL of the electrolyte solution in a 250 mL glass round-bottom beaker dedicated to the Multisizer 3. Place the beaker on the sample stage and stir counterclockwise at 24 rpm using a stirring rod. Remove dirt and bubbles from the nozzle using the "Nozzle Rinse" function in the dedicated software.

[0101] (2) About 30 ml of the electrolytic aqueous solution was placed in a 100 mL glass flat-bottom beaker. Then, "CONTAMINON N" (a 10% by mass aqueous solution of a pH 7 neutral detergent for cleaning precision measuring equipment, composed of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) was diluted by adding deionized water 3 times its mass to obtain about 0.3 mL of a diluted solution.

[0102] (3) A predetermined amount of deionized water was placed in a water tank of an ultrasonic disperser "Ultrasonic DispersionSystem Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.) having a power output of 120 W and equipped with two oscillators having an oscillation frequency of 50 kHz and the phases of the oscillators being shifted 180 degrees from each other, and about 2 mL of CONTAMINON N was added to the water tank.

[0103] (4) The beaker of (2) is placed in the beaker fixing hole of the ultrasonic disperser and the ultrasonic disperser is started. Then, the height of the beaker is adjusted to maximize the resonance state of the liquid surface of the electrolytic aqueous solution in the beaker.

[0104] (5) While the electrolytic aqueous solution in the beaker of (4) is being irradiated with ultrasound, approximately 10 mg of the toner is gradually added to the electrolytic aqueous solution and dispersed therein. The ultrasonic dispersion treatment is then continued for a further 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is adjusted to a temperature of 10°C to 40°C, as appropriate.

[0105] (6) The electrolytic aqueous solution of (5) above, in which the toner is dispersed, is dropped into the round-bottom beaker of (1) above, which has been set on the sample stage, using a pipette to adjust the measurement concentration to about 5%. Then, measurement is performed until the number of particles measured reaches 50,000.

[0106] (7) Use the dedicated software included with the device to analyze the measurement data and calculate D10, D50, and D90.

[0107] Preferably, the following expression (3) is satisfied, where σs represents the absolute value of the average value of the surface charge density of the second group in the toner, and σl represents the absolute value of the average value of the surface charge density of the first group.

[0108] 0.10≤σl / σs≤0.75 (3)

[0109] The surface charge density σ of a toner can be measured by the following method. As described above, the toner is divided into two roughly equal groups based on the number of particles: a first group with larger particles and a second group with smaller particles, thereby generating a first group and a second group. The surface charge density σ of each of the two divided toners is then measured.

[0110] First, 0.7 g of toner and 9.3 g of the Imaging Society of Japan standard carrier (N-01) were placed in a 50 ml resin bottle at 23°C and 50% RH. The toner was then triboelectrically charged using a YAYOI shaker at 200 rpm for 5 minutes. The charge distribution measurement device was then used to measure the charge per toner particle for each particle size.

[0111] Herein, an E-SPART analyzer (manufactured by Hosokawa Micron Corporation) can be used for measurement. The E-SPART analyzer is a device in which sample particles are introduced into a detection unit (measurement unit) in which an electric field and an acoustic field are simultaneously formed, and the moving speed of the particles is measured according to a laser Doppler method, thereby measuring the particle size and the charge amount.

[0112] The surface charge density σ is then calculated from the charge amount per toner particle for each particle size obtained in the measurement. Specifically, the surface charge density σ can be derived from the following expression.

[0113] σ=Q / πD 2

[0114] In the expression, Q is the amount of charge, and D is the number average particle size of the toner.

[0115] Since the colorant satisfies expression (3), fogging and transfer performance degradation caused by the small particle size colorant as the second group can be suppressed, the excessive increase in the toner charge amount per unit mass caused by the large particle size colorant as the first group can be reduced, and image density stability can be improved.

[0116] The number average particle size of the toner can be measured using a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark product name, manufactured by Beckman Coulter, Inc.) equipped with a 100 μm aperture tube. Measurement conditions can be set and measurement data can be analyzed using auxiliary dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.).

[0117] Preferably, the following expression (4) is satisfied, where σs represents the absolute value of the average value of the surface charge density of the second group.

[0118] 0.04≤σs (4)

[0119] Since the toner satisfies Expression (4), the charge amount of the small-particle-size toner is large; therefore, it becomes possible to reduce the amount of toner having a small electric field flying force, resulting in improved transferability and suppression of fogging.

[0120] Preferably, the following expression (5) is satisfied, where σl represents the absolute value of the average value of the first group of surface charge densities.

[0121] σl≤ 0.03 (5)

[0122] Since the toner satisfies Expression (5), the charge amount of the toner of the first group does not become excessively large; therefore, the charge amount per unit mass does not become excessive, and thus the image density stability can be improved accordingly.

[0123] The absolute value Qs of the average value of the charge amount per toner particle of the second group is preferably 1.4 fC or more. Therefore, the amount of particles having a small charge amount can be reduced, transferability can be improved, and fogging can be suppressed.

[0124] The absolute value Q1 of the average value of the charge amount per toner particle of the first group is preferably 2.8 fC or less. Therefore, it is possible to prevent the charge amount per unit mass of the toner from becoming excessively large, and improve image density stability.

[0125] Preferably, the charge amount per unit mass of the toner is 70 μC / g or less. Therefore, a decrease in image density can be suppressed. The charge amount per unit mass of the toner can be measured, for example, according to the method described below.

[0126] First, 0.7 g of toner and 9.3 g of a standard carrier (N-01) from the Japan Society of Imaging Science were placed in a 50 ml resin bottle at 23°C and 50% RH. The toner was then triboelectrically charged using a YAYOI shaker at 200 rpm for 5 minutes. Subsequently, 0.15 g of the triboelectrically charged toner was placed in a metal measuring container with a 635-mesh screen on the bottom, and the container was sealed with a metal lid. The mass of the entire measuring container was measured and recorded as W1 (g).

[0127] Afterwards, the vacuum gauge pressure is set to 1.5 kPa by adjusting the air volume control valve. The measuring container is then emptied through the suction port in a suction device (at least the portion of the suction device in contact with the measuring container is insulator-free). In this state, the toner is removed by thorough suction, preferably for two minutes. The amount of charge accumulated in the capacitor at this point is Q (μC). The mass of the entire measuring container after suction is weighed as W2 (g). The charge per unit mass of the toner (μC / g) is obtained using the following expression.

[0128] Charge quantity per unit mass of toner (μC / g) = Q / (W1-W2)

[0129] The method for bonding the polyolefin and the vinyl polymer (preferably by graft copolymerization) is not particularly limited, and a conventionally known method can be employed.

[0130] The monomer unit containing a sulfonic acid group can be formed by using a monomer having a sulfonic acid group. The monomer having a sulfonic acid group preferably has an ethylenically unsaturated bond, and more preferably has one ethylenically unsaturated bond.

[0131] A (meth)acrylamidesulfonic acid derivative is preferable as the vinyl monomer having a sulfonic acid group.

[0132] Examples include, for example, 2-acrylamide propanesulfonic acid, 2-acrylamide-n-butanesulfonic acid, 2-acrylamide-n-hexanesulfonic acid, 2-acrylamide-n-octanesulfonic acid, 2-acrylamide-n-dodecanesulfonic acid, 2-acrylamide-n-tetradecanesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, 2-acrylamide-2-phenylpropanesulfonic acid, 2-acrylamide-2,2,4-trimethylpentanesulfonic acid, 2-acrylamide-2-methylphenylethanesulfonic acid, 2-acrylamide-2-(4-chlorophenyl)propanesulfonic acid, 2-acrylamide-2-carboxymethylpropanesulfonic acid, 2-acrylamide-2-(2-pyridyl)propanesulfonic acid, 2-acrylamide-1-methylpropanesulfonic acid, 3-acrylamide-3-methylbutanesulfonic acid, 2-methacrylamide-n-decanesulfonic acid, and 2-methacrylamide-n-tetradecanesulfonic acid. 2-acrylamide-2-methylpropanesulfonic acid is preferred herein.

[0133] The monomer unit having a sulfonic acid group is preferably represented by the following formula (C).

[0134]

[0135] In formula (C), R 1 represents a hydrogen atom or a methyl group (preferably a hydrogen atom). In addition, X represents a linear or branched alkylene group having a carbon number of 1 to 8 (preferably 2 to 6, more preferably 4 to 6, and still more preferably 4).

[0136] The polyolefin resin having a sulfonic acid group is a polymer in which a vinyl polymer is bonded to a polyolefin. Preferably, the vinyl polymer has a structure derived from cycloalkyl (meth) acrylate. The term "structure derived from cycloalkyl (meth) acrylate" refers to a structure resulting from the polymerization of an acryloyl group or a methacryloyl group contained in the cycloalkyl (meth) acrylate in the vinyl polymer. Preferably, the vinyl polymer is a polymer of cycloalkyl (meth) acrylate, a vinyl monomer other than cycloalkyl (meth) acrylate, and a monomer having a sulfonic acid group.

[0137] Preferably, a C3 to C18 saturated alicyclic hydrocarbon group, more preferably a C4 to C12 saturated alicyclic hydrocarbon group, is used herein as the cycloalkyl group of the cycloalkyl (meth) acrylate. The saturated alicyclic hydrocarbon group includes, for example, a monocyclic saturated alicyclic hydrocarbon group, a condensed polycyclic hydrocarbon group, a bridged ring hydrocarbon group, and a spirocyclic hydrocarbon group.

[0138] Examples of saturated alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, tert-butylcyclohexyl, cycloheptyl, cyclooctyl, tricyclodecyl, decahydro-2-naphthyl, tricyclo[5.2.1.0 2,6 ]Decan-8-yl(tricyclo[5.2.1.0 2,6 ]decan-8-yl group), pentacyclopentadecanyl, isobornyl, adamantyl, dicyclopentyl and tricyclopentyl.

[0139] The saturated alicyclic hydrocarbon group may have as a substituent an alkyl group, a halogen atom, a carboxyl group, a carbonyl group, a hydroxyl group, etc. The substituent preferably used as the alkyl group herein is a C1 to C4 alkyl group.

[0140] Among these saturated alicyclic hydrocarbon groups, C3 to C18 monocyclic saturated alicyclic hydrocarbon groups, substituted or unsubstituted dicyclopentyl groups, and substituted or unsubstituted tricyclopentyl groups are more preferred, while C6 to C10 cycloalkyl groups are still more preferred, and cyclohexyl groups are particularly preferred herein.

[0141] The content of the monomer unit derived from cycloalkyl(meth)acrylate in the vinyl polymer is preferably from 1.0% by mass to 10.0% by mass.

[0142] Preferably, the polyolefin-based resin having a sulfonic acid group has a weight average molecular weight (Mw) of 5,000 to 70,000 in molecular weight distribution by GPC.

[0143] Other vinyl monomers besides cycloalkyl (meth)acrylates can be used for the vinyl polymer.Preferred herein are monomers having one ethylenically unsaturated bond.

[0144] Examples thereof include acrylic acid and methacrylic acid; styrene monomers such as styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, p-methoxystyrene, p-hydroxystyrene, p-acetoxystyrene, vinyltoluene, ethylstyrene, phenylstyrene, and benzylstyrene; alkyl esters of unsaturated carboxylic acids (wherein the number of carbon atoms in the alkyl group is 1 to 18) such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate; vinyl ester monomers such as vinyl acetate; vinyl ether monomers such as vinyl methyl ether; halogen-containing vinyl monomers such as vinyl chloride; and diene monomers such as butadiene and isobutylene. These can be used in any of their plurality.

[0145] Styrenic monomers and alkyl esters of unsaturated carboxylic acids are preferred herein.

[0146] The content ratio of the vinyl polymer in the polyolefin resin having a sulfonic acid group is preferably 80.0% by mass to 95.0% by mass, and more preferably 85.0% by mass to 95.0% by mass.

[0147] Suitable examples of polyolefins include low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, and hydrocarbon waxes such as microcrystalline wax and paraffin wax.

[0148] From the viewpoint of reactivity when producing a polyolefin-based resin having a sulfonic acid group, it is preferred that the polyolefin have a branched structure as in polypropylene.

[0149] The content ratio of the polyolefin in the polyolefin-based resin having a sulfonic acid group is preferably 5.0 to 20.0% by mass.

[0150] The content ratio of the polyolefin-based resin having a sulfonic acid group is preferably 3 parts by mass to 15 parts by mass, more preferably 5 parts by mass to 15 parts by mass, relative to 100 parts by mass of the binder resin.

[0151] There is no particular limitation on the method of further localizing the polyolefin-based resin having a sulfonic acid group near the surface of the toner particles of the second group (small-particle-size toner).

[0152] In some methods, for example, a release agent is mixed into the toner particles and then heat-treated. The polyolefin-based resin having a sulfonic acid group is a polymer in which a vinyl-based polymer is bonded to a polyolefin. Therefore, when using a Figure 1 When the surface treatment apparatus shown in treats the surface of the toner particles with hot air, the release agent serves as a driving force, whereby the polyolefin-based resin is oriented on the surface of the toner particles.

[0153] In this case, the surface area of ​​the toner with a small particle size is large, and therefore the toner is more easily affected by the hot air, thereby promoting the localization of the polyolefin-based resin on the toner surface.

[0154] For example, you can use Figure 1 The surface treatment device shown in the figure performs surface treatment by hot air. Figure 1 The surface treatment apparatus shown in FIG treats toner particles with hot air in a hydrophobic field in air, causing the release agent contained in the toner particles to migrate toward the vicinity of the toner particle surface as needed. As a result, the hydrophobicity of the toner surface increases, reducing water adsorption in high-temperature, high-humidity environments. Furthermore, low non-electrostatic adhesion can be maintained, resulting in excellent developing performance and easily suppressing fogging.

[0155] <Binder Resin>

[0156] From the viewpoint of low-temperature fixing property, the toner particles contain a binder resin comprising a polyester resin. The binder resin may contain a resin other than the polyester resin as long as the effects of the present invention are not impaired. The polyester resin is preferably a non-crystalline polyester resin.

[0157] The following non-crystalline resins can be used as the resin other than the polyester resin in the binder resin.

[0158] Single polymers of styrene, such as polystyrene, poly(p-chlorostyrene), polyvinyltoluene and substituted products thereof; styrene copolymers, such as styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer and styrene-methacrylate copolymer; as well as polyvinyl chloride, phenolic resin, natural resin-modified phenolic resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyurethane resin, polyamide resin, furan resin, epoxy resin, xylene resin, polyethylene resin and polypropylene resin.

[0159] Polyhydric alcohols (divalent, trivalent or higher-valent alcohols) and polycarboxylic acids (divalent, trivalent or higher-valent carboxylic acids) and their anhydrides and lower alkyl esters are used as monomers for the polyester resin.

[0160] In order to produce "strain curing properties," it is effective herein to induce partial crosslinking within the molecules of the amorphous resin to produce a branched polymer. To this end, a polyfunctional compound having a valence of three or more is preferably used. Therefore, the starting monomers of the polyester resin preferably include a trivalent or higher carboxylic acid, an anhydride or lower alkyl ester thereof, and / or a trivalent or higher alcohol.

[0161] Examples of the polyol monomer that can be used in the polyester resin include the following polyol monomers.

[0162] Examples of the diol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, bisphenols represented by formula (A) and derivatives thereof, and diols represented by formula (B).

[0163]

[0164] (In formula (A), R is an ethylene group or a propylene group, x and y are each an integer greater than or equal to 0, and the average value of x+y is 0 to 10).

[0165]

[0166] (In formula (B), R′ is —CH2CH2-, —CH2CH(CH3)-, or —CH2C(CH3)2-; x and y are each an integer greater than or equal to 0; and the average value of x+y is 0 to 10).

[0167] Examples of trivalent or higher alcohol components include sorbitol, 1,2,3,6-hexanetetraol, 1,4-anhydrosorbitol, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylglycerol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene. Among them, glycerol, trimethylolpropane, and pentaerythritol are preferably used. These dihydric alcohols and trihydric or higher alcohols can be used alone or in combination.

[0168] The following polycarboxylic acid monomers can be used as the polycarboxylic acid monomer for the polyester resin.

[0169] Examples of the dicarboxylic acid component include 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-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, n-octylsuccinic acid, isooctenylsuccinic acid, isooctylsuccinic acid, anhydrides of these acids, and lower alkyl esters thereof. Among these, maleic acid, fumaric acid, terephthalic acid, and n-dodecylsuccinic acid are preferably used.

[0170] Examples of trivalent or higher carboxylic acids, anhydrides thereof, and lower alkyl esters thereof include 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-dicarboxy-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra(methylenecarboxy)methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, Empol trimer acid, anhydrides thereof, and lower alkyl esters thereof.

[0171] Among them, 1,2,4-benzenetricarboxylic acid, ie, trimellitic acid or a derivative thereof is particularly preferably used because it is inexpensive and reaction control is easy. These dicarboxylic acids and trivalent or higher carboxylic acids may be used alone or in combination of multiple types.

[0172] The method for producing the polyester resin is not particularly limited, and a known method may be used. For example, the polyester resin may be produced by simultaneously adding and polymerizing the alcohol monomer and the carboxylic acid monomer through an esterification reaction or an ester exchange reaction and a condensation reaction.

[0173] The polymerization temperature is not particularly limited, but is preferably within a range of 180° C. to 290° C. In the polymerization of the polyester resin, for example, a polymerization catalyst such as a titanium-based catalyst, a tin-based catalyst, zinc acetate, antimony trioxide, or germanium dioxide can be used. In particular, when the polyester resin is a non-crystalline resin, the non-crystalline resin is more preferably a polyester resin polymerized using a tin-based catalyst.

[0174] The polyester resin preferably has an acid value of 5 to 20 mgKOH / g, and a hydroxyl value of 20 to 70 mgKOH / g. Within these ranges, moisture adsorption in a high-temperature, high-humidity environment can be suppressed, and non-electrostatic adhesion can be kept low, which is preferable from the perspective of suppressing fogging.

[0175] The polyester resin can be used by mixing a low molecular weight resin and a high molecular weight resin. From the viewpoint of low temperature fixing property and hot offset resistance, the content ratio of the low molecular weight resin to the high molecular weight resin is preferably 40 / 60 to 85 / 15 by mass.

[0176] <Crystalline Resin>

[0177] The toner particles may contain a crystalline resin. A polycondensate of a known polycarboxylic acid and a known polyol may be used as the crystalline resin. Preferably, the crystalline resin is a crystalline polyester resin.

[0178] Crystalline polyester resins have a high concentration of ester groups in their molecules. It is believed that crystalline polyester resins readily adsorb water molecules because their ester groups readily form hydrogen bonds with atmospheric water molecules. Therefore, the amount of water adsorbed on the toner can be controlled based on the crystalline polyester resin content in the toner.

[0179] The crystalline resin is preferably a condensation polymer of a C4 to C18 aliphatic diol and a C4 to C18 aliphatic dicarboxylic acid.

[0180] Within the above range, the concentration of ester groups in the molecule is satisfactory, hydrogen bonds with atmospheric water molecules are not excessively formed, and the amount of water absorbed by the toner is stabilized. Furthermore, the compatibility between the binder resin and the crystalline resin is enhanced, and the crystalline resin is easily and uniformly dispersed in the toner. Therefore, it is believed that the ester groups derived from the crystalline polyester resin can be stably present near the surface of the toner particles, resulting in the ability to easily control the amount of water absorbed by the toner.

[0181] The content of the crystalline resin is preferably 1.0 part by mass to 15.0 parts by mass, and more preferably 3.0 parts by mass to 10.0 parts by mass, relative to 100.0 parts by mass of the binder resin.

[0182] When the content of the crystalline resin is within the above range, the ester groups derived from the crystalline resin on the surfaces of the toner particles do not become excessive, and the amount of moisture adsorbed on the toner is stabilized.

[0183] <Release Agent (Wax)>

[0184] Waxes can be used as release agents in toner particles. Examples include the following.

[0185] Hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline waxes, paraffin waxes, and Fischer-Tropsch waxes; oxides of hydrocarbon waxes such as oxidized polyethylene wax or block copolymers thereof; waxes based on fatty acid esters such as carnauba wax; partially or completely deoxygenated fatty acid esters such as deoxygenated carnauba wax. In addition, the following may be mentioned.

[0186] Saturated straight-chain fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassinoic acid, eleostearic acid, and parinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohols, behenyl alcohol, carnauba alcohol, wax alcohol, and myricol; polyols such as sorbitol; esters of fatty acids such as palmitic acid, stearic acid, behenyl alcohol, and montanic acid with alcohols such as stearyl alcohol, aralkyl alcohols, behenyl alcohol, carnauba alcohol, wax alcohol, and myricol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; saturated fatty acid bisamides such as methylene bis(stearamide), ethylene bis(capramide), ethylene bis(lauramide), and hexamethylene bis(stearamide); unsaturated fatty acid amides such as ethylene bis(stearamide). Ethylbis(oleamide), hexamethylenebis(oleamide); N,N'-dioleyl adipamide, and N,N'-dioleyl sebacamide; aromatic bisamides, such as m-xylene bis(stearamide) and N,N'-distearylisophthalamide; fatty acid metal salts, such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate (commonly referred to as metal soaps); waxes obtained by grafting aliphatic hydrocarbon waxes with vinyl monomers such as styrene or acrylic acid; partial esterification products of fatty acids with polyols, such as monoglyceride of behenate; and methyl ester compounds having a hydroxyl group obtained by hydrogenation of vegetable oils and fats.

[0187] Among these waxes, hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax, and fatty acid ester waxes such as carnauba wax are preferred from the perspective of improving low-temperature fixability and fixation separation properties. Hydrocarbon waxes are more preferred from the perspective of further improving hot offset resistance. The wax content is preferably 3 to 15 parts by mass per 100 parts by mass of the binder resin.

[0188] Furthermore, in an endothermic curve at a temperature increase measured with a differential scanning calorimetry (DSC) apparatus, the peak temperature of the maximum endothermic peak of the wax is preferably from 45° C. to 140° C. This range of the peak temperature of the maximum endothermic peak of the wax is preferred because both storage stability and hot offset resistance of the toner can be achieved.

[0189] <Colorant>

[0190] The toner particles of the present invention may contain a colorant. Examples of colorants are listed below. Examples of black colorants include carbon black and colorants toned to black using yellow, magenta, or cyan colorants. Pigments alone may be used as colorants, but in terms of image quality in full-color images, it is more preferable to use a combination of dyes and pigments to improve clarity.

[0191] Examples of magenta toner pigments include the following: CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57:1, 58, 6 0, 63, 64, 68, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, and 282; CI Pigment Violet 19; and CI Vat Red 1, 2, 10, 13, 15, 23, 29, and 35.

[0192] Examples of magenta toner dyes include the following: CI Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, and 121; CI Disperse Red 9; CI Solvent Violet 8, 13, 14, 21, and 27; oil-soluble dyes such as CI Disperse Violet 1, CI Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, and 40; and basic dyes such as CI Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, and 28.

[0193] Examples of cyan toner pigments include the following: CI Pigment Blue 2, 3, 15:2, 15:3, 15:4, 16, and 17; CI Vat Blue 6; CI Acid Blue 45; and copper phthalocyanine pigments in which the phthalocyanine skeleton is substituted with 1 to 5 phthalimidomethyl groups.

[0194] Examples of cyan toner dyes include CI Solvent Blue 70.

[0195] Examples of yellow toner pigments include the following: CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, and 185; and CI Vat Yellow 1, 3, and 20.

[0196] Examples of yellow toner dyes include CI Solvent Yellow 162.

[0197] These colorants may be used alone or as a mixture thereof, and may also be used in a solid solution state.The colorant is selected from the viewpoints of hue angle, chroma, brightness, light resistance, OHP transparency, and dispersibility in toner.

[0198] The content of the colorant is preferably 0.1 parts by mass to 30.0 parts by mass relative to 100 parts by mass of the binder resin.

[0199] <Inorganic fine particles>

[0200] The toner may contain inorganic fine particles as needed.

[0201] The inorganic fine particles may be internally added to the toner particles, or may be mixed with the toner particles as an external additive.

[0202] Preferred external additives are the inorganic fine particles herein, such as silica fine particles, aluminum oxide fine particles, titanium oxide fine particles, and strontium titanate fine particles. From the perspective of suppressing fogging and improving transfer efficiency, low-resistance external additives, such as titanium oxide fine particles or strontium titanate fine particles, are particularly preferred because variations in charge amount due to temperature and humidity can be reduced, thereby suppressing localization of toner charge and weakening electrostatic adhesion. The inorganic fine particles are preferably hydrophobized using a hydrophobic agent such as a silane compound, silicone oil, or a mixture thereof.

[0203] In order to improve fluidity, it is preferred to have a 50m 2 / g to 400m 2 Inorganic fine particles having a specific surface area of ​​1000 nm / g are used as external additives.

[0204] The toner particles and the external additive can be mixed using a known mixer such as a Henschel mixer. The content of the external additive is preferably 0.1 to 10.0 parts by mass relative to 100 parts by mass of the toner particles.

[0205] <Developer>

[0206] The toner can be used as a one-component developer, but can also be mixed with a magnetic carrier and used as a two-component developer for the purpose of further improving dot reproducibility and for the purpose of providing stable images over a long period of time.

[0207] Magnetic carriers include generally known materials such as iron oxides; metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium and rare earth, alloy particles thereof, and oxide particles thereof; magnetic bodies such as ferrite; magnetic body-dispersed resin carriers (so-called resin carriers) including a binder resin in which the magnetic body is maintained in a dispersed state; and the like.

[0208] When the toner is mixed with a magnetic carrier and used as a two-component developer, the mixing ratio of the magnetic carrier at this time is preferably 2% by mass to 15% by mass, and more preferably 4% by mass to 13% by mass based on the toner concentration in the two-component developer.

[0209] <Toner Manufacturing Method>

[0210] The method for producing toner particles is not particularly limited, but a pulverization method is preferred from the perspective of dispersing the polyolefin resin having sulfonic acid groups, for example. In this method, the highly hydrophobic release agent and the polyolefin resin can be easily localized near the surface of the toner particles. As a result, the polyolefin resin can be easily localized near the surface of the toner particles passing through the heat treatment apparatus.

[0211] Next, a toner production process in the pulverization method will be described.

[0212] Preferably, the toner production method includes the following steps: a step of obtaining a kneaded product by melt-kneading a resin composition containing a binder resin including a polyester resin and a polyolefin-based resin having a sulfonic acid group;

[0213] a step of obtaining a cooled product by cooling the kneaded product;

[0214] a step of obtaining toner particles by pulverizing the cooled product; and

[0215] A step of subjecting the toner particles to a heat treatment by hot air.

[0216] In the raw material mixing step, materials constituting the toner particles, for example, a binder resin comprising a polyester resin, a polyolefin-based resin having a sulfonic acid group, and other components such as a release agent, a colorant, a charge control agent, etc. as needed, are weighed in predetermined amounts, blended, and mixed to produce a resin composition.

[0217] Examples of the mixing apparatus include a double cone mixer, a V-type mixer, a drum mixer, a supermixer, a Henschel mixer, a NAUTA mixer, and MECHANO HYBRID (manufactured by Nippon Coke Industry Co., Ltd.).

[0218] Thereafter, the mixed resin composition is melt-kneaded to obtain a kneaded product in which the material is dispersed in the binder resin. In the melt-kneading process, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used, and a single-screw or twin-screw extruder is preferably used due to its superiority in continuous production.

[0219] Specific examples of the single-screw or twin-screw extruder include a KTK-type twin-screw extruder (manufactured by Kobe Steel, Ltd.), a TEM-type twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), a PCM kneader (manufactured by Ikegai Corp.), a twin-screw extruder (manufactured by KCK Co.), a co-kneader (manufactured by Buss AG) and KNEADEX (manufactured by Nippon Coke & Engineering Co., Ltd.).

[0220] Furthermore, the resin composition obtained by melt-kneading may be rolled using a two-roll mill or the like, or may be cooled using water or the like in a cooling step.

[0221] The cooled product obtained by cooling is then pulverized to a desired particle size in a pulverization step. In the pulverization step, coarse pulverization is performed using a pulverization device such as a crusher, a hammer mill, or a feather mill. Thereafter, the material is finely pulverized using, for example, a KRYPTON system (manufactured by Kawasaki Heavy Industries, Ltd.), a SUPER ROTOR (manufactured by Nisshin Engineering Co., Ltd.), a TURBO MILL (manufactured by Turbo Kogyo), or an air jet type fine pulverization device to obtain toner particles.

[0222] Then, the toner particles are classified using a classifier or sifter as needed. Examples of classifiers and sifters include, for example, the following: Elbow-jet inertial classification system (manufactured by Nittetsu Mining Co., Ltd.), centrifugal classification system Turboplex (manufactured by Hosokawa Micron Corporation), TSP separator (manufactured by Hosokawa Micron Corporation), and FACULTY (manufactured by Hosokawa Micron Corporation).

[0223] Thereafter, the toner particles may be surface treated by heating to increase the circularity of the toner. For example, Figure 1 The surface treatment apparatus shown in performs surface treatment by hot air.

[0224] Next, we will explain how to use Figure 1 Surface treatment of the surface treatment device shown in .

[0225] The mixture dispensed by the raw material metering unit 1 is guided to an inlet pipe 3 mounted vertically to the raw material supply unit by compressed gas regulated by a compressed gas regulating unit 2. The mixture passing through the inlet pipe is evenly dispersed by a conical protruding member 4 provided in the center of the raw material supply unit and guided to eight directional supply pipes 5 extending radially in various directions. The mixture is then guided to a processing chamber 6, where it undergoes heat treatment.

[0226] At this time, the mixture flow supplied to the treatment chamber 6 is regulated by a regulating member 9 provided in the treatment chamber 6 for regulating the mixture flow. For this purpose, the mixture supplied to the treatment chamber 6 is cooled after the heat treatment while swirling in the treatment chamber 6.

[0227] The hot air for heat treating the supplied mixture is supplied from the hot air supply part 7 via the inlet 11 of the processing chamber 6, and is swirled by the swirl member 13 for swirling the hot air and introduced into the processing chamber 6. As a specific configuration, the swirl member 13 for swirling the hot air can have a plurality of blades, and the swirl of the hot air can be controlled by the number and angle of the blades.

[0228] The temperature of the hot air supplied into the processing chamber 6 at the outlet of the hot air supplying member 7 is preferably 100° C. to 300° C. When the temperature at the outlet of the hot air supplying member 7 is within the above range, the toner particles can be uniformly sphericalized while preventing fusion or aggregation of the toner particles due to excessive heating of the mixture.

[0229] Furthermore, the heat-treated toner particles subjected to heat treatment are cooled by cold air supplied from the cold air supplying means 8 (8-1, 8-2, 8-3), and the temperature of the cold air supplied from the cold air supplying means 8 is preferably -20°C to 30°C. When the temperature of the cold air is within the above range, the heat-treated toner particles can be effectively cooled, and fusion or agglomeration of the heat-treated toner particles can be prevented without inhibiting uniform sphericalization of the mixture. The absolute water content of the cold air is preferably 0.5 g / m 3 Up to 15.0g / m 3 .

[0230] Thereafter, the cooled heat-treated toner particles are collected by a collecting member 10 at the lower end of the processing chamber 6. A blower (not shown) is provided at the end of the collecting member 10 and is configured to ensure suction and transportation of the toner particles.

[0231] Furthermore, a powder particle supply port 14 is provided so that the swirl direction of the supplied mixture is the same as that of the hot air, and a collecting member 10 of the surface treatment device is provided on the periphery of the treatment chamber 6 to maintain the swirl direction of the swirling powder particles. Furthermore, cold air supplied from the cold air supply member 8 is supplied horizontally and tangentially from the periphery of the device to the peripheral surface of the treatment chamber.

[0232] The swirl direction of the toner particles supplied from the powder supply port, the swirl direction of the cold air supplied from the cold air supply unit 8, and the swirl direction of the hot air supplied from the hot air supply unit 7 are all the same. Therefore, turbulence does not occur in the processing chamber 6, the swirl flow in the device is enhanced, a strong centrifugal force is applied to the toner particles, and the dispersibility of the toner particles is further improved. As a result, toner particles with almost no agglomerated particles and a uniform shape can be obtained.

[0233] From the viewpoint of suppressing fogging, the average circularity of the toner particles is preferably within a range of 0.960 to 0.980 because the non-electrostatic adhesive force can be kept low within this range.

[0234] The toner can then be divided into two, as needed, into a fine powder toner and a coarse powder toner. For example, the toner can be divided into two using an Elbow-jet classification inertial classification system (manufactured by Nittetsu Mining Co., Ltd.). Any fine powder toner and any coarse powder toner can be mixed to obtain the desired physical properties. The obtained toner particles can be used as a toner as is; alternatively, the toner particles can be used as a toner after inorganic fine particles, such as fine silica particles, are externally added to the toner particles.

[0235] Methods involving external addition include, for example, methods using a mixing device as an external addition machine for stirring / mixing. Examples of mixing devices include the following. Double cone mixer, V-shaped mixer, drum mixer, high-speed mixer, Henschel mixer, Nauta mixer, Mechano Hybrid (manufactured by Nippon Coke & Engineering Co., Ltd.) and Nobilta (manufactured by Hosokawa Micron Corporation). At this time, external additives other than fine silica particles such as a fluidizing agent may be used as needed.

[0236] Next, methods of measuring various physical properties of the toner and raw materials will be described.

[0237] <FT-IR Spectrometry of Toner (Calculation of As, Al, Bs, and Bl)>

[0238] As samples, the first and second groups described above were obtained by using an Elbow-jet classifier (manufactured by Nittetsu Mining Co., Ltd.) of the inertial classification system described above toners divided into two roughly equal parts based on the number, that is, into a first group on the larger particle size side and a second group on the smaller particle size side.

[0239] Here, the FT-IR spectrum of the toner is measured according to the ATR method using a Fourier transform infrared spectrometer (trade name: Spectrum One, manufactured by PerkinElmer, Inc.) equipped with a universal ATR measurement accessory (universal ATR sampling accessory). The specific measurement procedure and the method for calculating As, Al, Bs, and Bl are as follows.

[0240] The incident angle of infrared light (λ=5 μm) was set to 45°. In addition, an ATR crystal of Ge (refractive index=4.0) or an ATR crystal of diamond (refractive index=2.4) was used as the ATR crystal. Other conditions were as follows.

[0241] scope

[0242] Start: 4000cm -1

[0243] End: 600cm -1 (Ge ATR crystal)

[0244] 400cm -1 (Diamond ATR Crystal)

[0245] Duration

[0246] Number of scans: 16

[0247] Resolution: 4.00cm -1

[0248] Advanced: CO2 / H2O Correction

[0249] (1) A Ge ATR crystal (refractive index = 4.0) was set in the device.

[0250] (2) Set the scan type to background, the unit to EGY, and measure the background.

[0251] (3) Set the scan type to sample and the unit to A.

[0252] (4) Then, 0.01 g of the toner is accurately weighed onto the ATR crystal.

[0253] (5) Use the pressure arm (dynamometer 100) to pressurize the sample.

[0254] (6) Measure the sample.

[0255] (7) The obtained FT-IR spectra were baseline corrected using automatic correction.

[0256] (8) Calculated at 1130cm -1 to 1170cm -1 The maximum absorption peak intensity in the range of 1713 cm is divided by -1 to 1723cm -1 The maximum absorption peak intensities within the range of 100 nm were used to calculate the As and Al contents.

[0257] (9) For diamond crystals, the same method is used to measure and calculate Bs and Bl.

[0258] <Measurement of Peak Molecular Weight and Weight Average Molecular Weight of Binder Resin and Polyolefin Resin Having Sulfonic Acid Groups by GPC>

[0259] The molecular weight distribution of the THF soluble matter of the resin was measured by gel permeation chromatography (GPC) in the following manner.

[0260] First, the sample was dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. The resulting solution was then filtered through a solvent-resistant membrane filter "MAESHORI DISK" (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution was adjusted so that the concentration of the THF-soluble component was approximately 0.8% by mass. This sample solution was used for measurement under the following conditions.

[0261] Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)

[0262] Column: 7 Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK) connected in series

[0263] Eluent: tetrahydrofuran (THF)

[0264] Flow rate: 1.0ml / min

[0265] Box temperature: 40.0℃

[0266] Sample injection volume: 0.10ml

[0267] When calculating the molecular weight of a sample, a molecular weight calibration curve is prepared using a standard polystyrene resin (e.g., trade name "TSK standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500", manufactured by Tosoh Corporation).

[0268] <Method for measuring the softening point of the binder resin and the polyolefin resin having a sulfonic acid group>

[0269] Softening point measurements were performed using a constant-load extrusion capillary rheometer, the "Flow Measurement Evaluation Device Flow Tester CFT-500D" (manufactured by Shimadzu Corporation), according to the manual that came with the instrument. In this device, the temperature of a sample filled in a cylinder is raised, and the sample is melted while a constant load is applied from the top of the sample by a piston. The molten sample is then extruded from a die at the bottom of the cylinder, yielding a flow curve showing the relationship between the amount of piston descent and the temperature at that time.

[0270] The softening point is defined as the "1 / 2 method melting temperature" described in the manual for the "Flow Measurement Evaluation Device Flow Tester CFT-500D." The 1 / 2 method melting temperature is calculated as follows. First, determine half the difference between the piston's descent Smax at the end of flow and the piston's descent Smin at the start of flow (denoted as X, X = (Smax - Smin) / 2). The temperature at which the piston's descent in the flow curve equals the sum of X and Smin is the 1 / 2 method melting temperature.

[0271] The measurement sample is prepared by compression-molding 1.0 g of the resin into a cylinder having a diameter of 8 mm at 10 MPa for 60 seconds under an environment of 25° C. using a tablet press (eg, NT-100H, manufactured by NPA Systems Inc.).

[0272] The measurement conditions of CFT-500D are as follows.

[0273] Test mode: heating method

[0274] Starting temperature: 50℃

[0275] Reaching temperature: 200℃

[0276] Measuring interval: 1.0℃

[0277] Heating rate: 4.0℃ / min

[0278] Piston cross-sectional area: 1.000cm 2

[0279] Test load (piston load): 10.0kgf / cm 2 (0.9807MPa)

[0280] Warm-up time: 300 seconds

[0281] Die hole diameter: 1.0mm

[0282] Die length: 1.0mm

[0283] <Measurement of Glass Transition Temperature (Tg) of Binder Resin and Polyolefin Resin Having Sulfonic Acid Group>

[0284] The glass transition temperature and melting peak temperature were measured using a differential scanning calorimeter "Q2000" (manufactured by TA Instruments) in accordance with ASTM D3418-82. The melting points of indium and zinc were used for temperature correction of the device's detection unit, and the heat of fusion of indium was used for caloric correction. Specifically, the measurement was performed under the following conditions: 3 mg of the resin was accurately weighed, the sample was placed in an aluminum pan, and an empty aluminum pan was used as a reference.

[0285] Heating rate: 10℃ / min

[0286] Measurement starting temperature: 30°C

[0287] Measurement end temperature: 180°C

[0288] The measurement is performed within a measurement range of 30°C to 100°C at a heating rate of 10°C / min. The temperature is raised to 180°C and held for 10 minutes, then lowered to 30°C and raised again. During this second heating process, the change in specific heat is measured within the temperature range of 30°C to 100°C. The intersection of the line midway between the baselines before and after the specific heat change at this point and the differential thermal curve is taken as the glass transition temperature (Tg).

[0289] <Method for Measuring Average Circularity of Toner Particles>

[0290] Under the same measurement and analysis conditions as during the calibration operation, the average circularity of the toner particles is measured using a flow particle image analyzer "FPIA-3000" (manufactured by Sysmex Corp.). The measurement principle using the flow particle image analyzer "FPIA-3000" (manufactured by Sysmex Corp.) is to capture the image of the flowing particles as a static image and perform image analysis. The sample added to the sample chamber is obtained by a sample suction syringe and supplied to the planar sheath flow cell. The sample supplied to the planar sheath flow cell is clamped by the sheath liquid to form a flat flow. The sample passing through the planar sheath flow cell is irradiated by a strobe light at intervals of 1 / 60 sec, and the image of the flowing particles can be captured as a static image. In addition, since the flow is planar, a focused image is captured. The image of the particles is captured by a CCD camera, and the captured image is processed with an image processing resolution of 512×512 pixels (0.37 μm×0.37 μm per pixel), and the projected area S and perimeter L of the particle image are determined by extracting the contour of each particle image.

[0291] Then, the equivalent circle diameter and circularity are obtained by using the area S and the circumference L. The equivalent circle diameter refers to the diameter of a circle having the same area as the projected area of ​​the particle image. The circularity is defined as the value calculated by dividing the circumference of the circle obtained based on the equivalent circle diameter by the circumference of the particle projected image using the following equation.

[0292] Circularity = 2 × (π × S) 1 / 2 / L.

[0293] When the particle image is a perfect circle, the circularity is 1.000. As the degree of concavity and convexity of the particle image's periphery increases, the circularity decreases. After calculating the circularity of each particle, the arithmetic mean of the obtained circularities is calculated and used as the average circularity.

[0294] The specific measurement method is as follows.

[0295] First, about 20 mL of ion-exchanged water from which solid impurities and the like had been previously removed was placed in a glass container. Then, 0.2 mL of a diluted solution prepared by diluting "CONTAMINON N" (a 10% by mass aqueous solution of a pH 7 neutral detergent for cleaning precision measuring equipment, containing a nonionic surfactant, an anionic surfactant, and an organic builder; manufactured by Wako Pure Chemical Industries, Ltd.) with about 3 times the mass of ion-exchanged water was added as a dispersant.

[0296] Then, about 0.02 g of the measurement sample was added and dispersed for 2 minutes using an ultrasonic disperser to obtain a dispersion liquid for measurement. At this time, the dispersion liquid was appropriately cooled so that its temperature was 10° C. to 40° C. A predetermined amount of ion-exchanged water was placed in a water tank, and then about 2 mL of CONTAMINON N was added to the water tank using a tabletop ultrasonic cleaner / disperser ("VS-150" (manufactured by Velvo-Clear Co., Ltd.)) having an oscillation frequency of 50 kHz and a power output of 150 W as an ultrasonic disperser.

[0297] In the measurement process, the above-mentioned flow particle image analyzer equipped with a standard objective lens (magnification: 10 times) was used, and a particle sheath "PSE-900A" (manufactured by Sysmex Corp.) was used as a sheath liquid. The dispersion liquid prepared according to the above-mentioned process was introduced into the flow particle image analyzer, and 3,000 toner particles were counted in the HPF measurement mode using the total count mode.

[0298] The average circularity of the toner particles is determined by setting the binarization threshold value in the particle analysis process to 85% and limiting the analyzed particle size to a circle-equivalent diameter of 1.98 μm to 39.69 μm.

[0299] During measurement, automatic focusing is performed using standard latex particles ("RESEARCH AND TEST PARTICLES, Latex Microsphere Suspensions 5200A" manufactured by Duke Scientific Corp.) before the start of measurement. Subsequently, focusing is preferably performed every 2 hours after the start of measurement.

[0300] <Separation of Polyolefin Resin from Toner and Measurement of Content Ratio of Vinyl Polymer and Monomer Unit Having Sulfonic Acid Group in Polyolefin Resin>

[0301] The polyolefin resin of the toner is separated according to the following method to allow identification of the content ratio of the monomer unit having a sulfonic acid group and the vinyl polymer in the polyolefin resin. Specifically, the release agent is extracted from the toner by Soxhlet extraction using a hexane solvent, so that only the polyolefin resin can be separated based on the difference in solubility of the polyester resin and the polyolefin resin with respect to the solvent.

[0302] Specific examples of methods for extracting the polyolefin resin include the following: Soxhlet extraction is performed using an ethyl acetate / 1-propanol mixed solvent (mass ratio 8:2) to separate the polyolefin resin as a residue. The residue can then be thoroughly dried and its mass measured to determine its content. This can be further accompanied by NMR analysis to determine the molecular structure of the polyolefin resin in the extracted residue.

[0303] Example

[0304] Next, the present invention will be described in more detail based on Examples and Comparative Examples, but the implementation of the present invention is not limited to these Examples. In Examples and Comparative Examples, the numerical values ​​of "parts" are based on parts by mass in all cases unless otherwise specified.

[0305] <Production Example of Polyolefin Resin 1>

[0306] 300.0 parts of xylene and 10.0 parts of polypropylene (melting point 81° C.) were fully dissolved in an autoclave reaction vessel equipped with a thermometer and a stirrer. After purging with nitrogen, a mixed solution of 74.7 parts of styrene, 0.9 parts of 2-acrylamide-2-methylpropanesulfonic acid, 3.6 parts of cyclohexyl methacrylate, 10.8 parts of butyl acrylate, and 250.0 parts of xylene was added dropwise at 180° C. for 3 hours to initiate polymerization. Upon completion of the polymerization reaction, the obtained mixed solution was cooled.

[0307] A mixed solution of 4.0 parts of a 10 mol / L lithium hydroxide aqueous solution and 16.0 parts of tetrahydrofuran was added dropwise, and the whole was maintained at this temperature for 30 minutes to cause neutralization. The solvent was then removed to produce polyolefin resin 1. The content ratios of the various monomer units are shown in Table 1.

[0308] <Production Examples of Polyolefin Resins 2 to 6>

[0309] Polyolefin resins 2 to 6 were obtained by performing the same operation as in the production example of polyolefin resin 1, except that 2-acrylamide-2-methylpropanesulfonic acid and butyl acrylate in the production example of polyolefin resin 1 were changed to those shown in Table 1. The content ratios of the various monomer units are shown in Table 1.

[0310] Polyolefin-based resin 6 was produced by the same operation as in the production example of polyolefin-based resin 1, except that 2-acrylamide-2-methylpropanesulfonic acid was not added.

[0311] [Table 1]

[0312]

[0313] In the table, AMPS represents 2-acrylamide-2-methylpropanesulfonic acid. The term "mass %" represents the content ratio of monomer units derived from various monomers in the vinyl polymer.

[0314] <Production Example of Amorphous Resin 1>

[0315] Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane: 73.8 parts (0.19 mol parts; relative to the total moles of the polyol, 100.0 mol%)

[0316] Terephthalic acid:

[0317] 12.5 parts (0.08 parts by mole; 48.0 mol% relative to the total moles of polycarboxylic acid)

[0318] Adipic acid:

[0319] 7.8 parts (0.05 parts by mole; 34.0 mol% relative to the total moles of polycarboxylic acid)

[0320] Tetrabutoxytitanium (esterification catalyst): 0.5 parts

[0321] The above materials were weighed in a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The interior of the reaction vessel was then purged with nitrogen, and the temperature was gradually increased while stirring. The reaction was continued at 200°C for 2 hours while stirring.

[0322] Thereafter, the pressure in the reaction container was reduced to 8.3 kPa and maintained at this state for 1 hour, and then cooled to 160° C. and returned to atmospheric pressure (first reaction step).

[0323] Trimellitic acid:

[0324] 5.9 parts (0.03 parts by mole; 18.0 mol% relative to the total moles of polycarboxylic acid)

[0325] Tert-butylcatechol (polymerization inhibitor): 0.1 part

[0326] Thereafter, the above materials were added, the pressure in the reaction vessel was reduced to 8.3 kPa, and the reaction was carried out for 15 hours while maintaining the temperature at 200° C.; once the softening point reached 120° C. as confirmed in the measurement according to ASTM D36-86, the temperature was lowered to stop the reaction (second reaction step), and amorphous resin 1 was obtained.

[0327] The obtained non-crystalline resin 1 had a peak molecular weight Mp of 10,000, a softening point Tm of 110°C, and a glass transition temperature Tg of 60°C.

[0328] <Production Example of Amorphous Resin 2>

[0329] Polyoxyethylene (2,2)-2,2-bis(4-hydroxyphenyl)propane: 73.8 parts (0.19 parts by mole; relative to the total moles of the polyol, 100.0 mol%)

[0330] Terephthalic acid

[0331] 12.5 parts (0.08 parts by mole; 48.0 mol% relative to the total moles of polycarboxylic acid)

[0332] Adipic acid:

[0333] 7.8 parts (0.05 parts by mole; 34.0 mol% relative to the total moles of polycarboxylic acid)

[0334] Tetrabutoxytitanium (esterification catalyst): 0.5 parts

[0335] The above materials were weighed in a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The interior of the reaction vessel was then purged with nitrogen, and the temperature was gradually increased while stirring. The reaction was continued at 200°C for 2.5 hours while stirring.

[0336] Thereafter, the pressure in the reaction container was reduced to 8.4 kPa and maintained at this state for 1 hour, and then cooled to 160° C. and returned to atmospheric pressure (first reaction step).

[0337] Trimellitic acid:

[0338] 5.9 parts (0.03 parts by mole; 18.0 mol% relative to the total moles of polycarboxylic acid)

[0339] Tert-butylcatechol (polymerization inhibitor): 0.1 part

[0340] After that, the above materials were added, the pressure in the reaction vessel was reduced to 8.3 kPa, and the reaction was carried out for 15 hours while maintaining the temperature at 205° C.; once the softening point was confirmed to have reached 120° C. in a measurement according to ASTM D36-86, the temperature was lowered to stop the reaction (second reaction step), and amorphous resin 2 was obtained. The obtained amorphous resin 2 had a peak molecular weight Mp of 10,000, a softening point Tm of 109° C., and a glass transition temperature Tg of 60.5° C.

[0341] <Manufacturing Example of Toner 1>

[0342]

[0343] A Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) was used to mix the mixture for 20 s. -1 The above materials were mixed at a rotation speed of 0.5 and a rotation time of 5 minutes, and then kneaded using a twin-screw kneader (PCM-30 model, manufactured by Ikegai Corp.). The barrel temperature during kneading was set so that the outlet temperature of the kneaded product was 120° C. The outlet temperature of the kneaded product was directly measured using a handheld thermometer (HA-200E, manufactured by Anritsu Meter Co., Ltd.).

[0344] The kneaded product obtained was cooled and coarsely pulverized to 1 mm or less using a hammer mill to produce a coarsely crushed product. The crushed product obtained was finely pulverized using a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.). The obtained product was classified using FACULTY F-300 (manufactured by Hosokawa Micron Corporation) to produce toner particles 1. The running condition was set to 130 s. -1 The rotor speed of the classifier and 120s -1 The dispersion rotor speed.

[0345] exist Figure 1 The obtained toner particles 1 were heat-treated in the surface treatment apparatus shown in , thereby obtaining heat-treated particles of the toner particles 1. The operating conditions included setting a feed rate of 5 kg / hr, a hot air temperature of 150° C., and a hot air flow rate of 6 m 3 / min, cold air temperature = -5℃, cold air flow = 4m 3 / min, blower air volume = 20m 3 / min and injection air flow rate = 1m 3 / min.

[0346] Then, 1.0 part of hydrophobic silica (BET: 200 m 2 / g) and 1.0 part of titanium oxide fine particles surface-treated with isobutyltrimethoxysilane (BET: 80 m 2 / g) was mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) for 30 s -1 The mixture was mixed at a rotation speed of 0.05 and a rotation time of 10 minutes to produce Toner 1.

[0347] <Manufacturing Example of Toner 2>

[0348] Toner 2 is obtained by performing the same operation as in the Production Example of Toner 1 except that the Polyolefin Resin 1 in the Production Example of Toner 1 is changed to the Polyolefin Resin 4.

[0349] <Manufacturing Example of Toner 3>

[0350]

[0351] A Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) was used to mix the mixture for 20 s. -1 The above materials were mixed at a rotation speed of 0.5 and a rotation time of 5 minutes, and then kneaded using a twin-screw kneader (PCM-30 model, manufactured by Ikegai Corp.). The barrel temperature during kneading was set so that the outlet temperature of the kneaded product was 120° C. The outlet temperature of the kneaded product was directly measured using a handheld thermometer (HA-200E, manufactured by Anritsu Meter Co., Ltd.).

[0352] The kneaded product was cooled and coarsely crushed to less than 1 mm using a hammer mill to produce a coarse crushed product. The kneaded crushed product was finely crushed using a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.) at a rotor speed of 12,000 rpm. Classification was then performed using a FACULTY (F-300, manufactured by Hosokawa Micron Corporation) at a classification rotor speed of 9,000 rpm and a dispersion rotor speed of 7,200 rpm to produce small-size toner particles F2 containing the polyolefin resin 2.

[0353] Then, a Henschel mixer (FM-75 type, manufactured by Mitsui Mining Co., Ltd.) was used to mix the mixture for 20 seconds. -1 The following materials were mixed at a rotation speed of 0.05 and a rotation time of 5 minutes, and then kneaded using a twin-screw kneader (PCM-30 model, manufactured by Ikegai Corporation). The cylinder temperature during kneading was set so that the outlet temperature of the kneaded product was 120°C.

[0354]

[0355] The cylinder temperature during kneading was set so that the outlet temperature of the kneaded product was 120° C. The outlet temperature of the kneaded product was directly measured using a hand-held thermometer (HA-200E, manufactured by Anritsu Meter Co., Ltd.).

[0356] The kneaded product was cooled and coarsely pulverized to less than 1 mm using a hammer mill to produce a coarsely crushed product. Pulverization and classification were performed with the mechanical pulverizer set at a rotor speed of 10,000 rpm and the FACULTY set at a classification rotor speed of 8,000 rpm and a dispersion rotor speed of 7,200 rpm to produce large-diameter toner particles M1 containing polyolefin resin 1.

[0357] The obtained small-size toner particles F2 containing polyolefin resin 2 and large-size toner particles M1 containing polyolefin resin 1 were mixed at a mass ratio of 1:1. Figure 1 , heat-treated particles of toner particles 3 were obtained by subjecting the toner particles to heat treatment using the surface treatment apparatus shown in .

[0358] The operating conditions involve setting feed rate = 5kg / hr, hot air temperature = 150℃, hot air flow rate = 6m 3 / min, cold air temperature = -5℃, cold air flow = 4m 3 / min, blower air volume = 20m 3 / min and injection air flow rate = 1m 3 / min.

[0359] Then, 1.0 part of hydrophobic silica fine particles (BET: 200 m 2 / g) and 1.0 part of titanium oxide fine particles surface-treated with isobutyltrimethoxysilane (BET: 80 m 2 / g) was mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) for 30 s -1 The mixture was mixed at a rotation speed of 0.05 and a rotation time of 10 minutes to produce Toner 3.

[0360] <Manufacturing Example of Toner 4>

[0361] Toner 4 herein is obtained by performing the same operations as in the manufacturing example of toner 3, except that the polyolefin resin 2 in the manufacturing example of toner 3 is replaced by the polyolefin resin 3, and the small-particle-size toner particles F3 containing the polyolefin resin 3 and the large-particle-size toner particles M1 containing the polyolefin resin 1 are mixed.

[0362] <Manufacturing Example of Toner 5>

[0363] Toner 5 herein is obtained by performing the same operations as in the manufacturing example of toner 3, except that the polyolefin resin 2 in the manufacturing example of toner 3 is replaced by the polyolefin resin 4, and the small-particle-size toner particles F4 containing the polyolefin resin 4 and the large-particle-size toner particles M1 containing the polyolefin resin 1 are mixed.

[0364] <Manufacturing Example of Toner 6>

[0365]

[0366] A Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) was used to mix the mixture for 20 s. -1 The above materials were mixed at a rotation speed of 0.5 and a rotation time of 5 minutes, and then kneaded using a twin-screw kneader (PCM-30 model, manufactured by Ikegai Corp.). The barrel temperature during kneading was set so that the outlet temperature of the kneaded product was 120° C. The outlet temperature of the kneaded product was directly measured using a handheld thermometer (HA-200E, manufactured by Anritsu Meter Co., Ltd.).

[0367] The kneaded product was cooled and coarsely crushed to less than 1 mm using a hammer mill to produce a coarse crushed product. The kneaded crushed product was finely crushed using a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.) under operating conditions involving a rotor speed of 12,000 rpm. Classification was performed using a FACULTY (F-300, manufactured by Hosokawa Micron Corporation) under operating conditions involving a classification rotor speed of 9,000 rpm and a dispersion rotor speed of 7,200 rpm to produce small-size toner particles F4-2 containing polyolefin resin 4.

[0368] Next, a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) was used to mix the mixture for 20 seconds. -1 The following materials were mixed at a rotation speed of 0.5 and a rotation time of 5 minutes, and then kneaded using a twin-screw kneader (PCM-30 model, manufactured by Ikegai Corporation). The cylinder temperature during kneading was set so that the outlet temperature of the kneaded product was 120°C.

[0369]

[0370] The cylinder temperature during kneading was set so that the outlet temperature of the kneaded product was 120° C. The outlet temperature of the kneaded product was directly measured using a hand-held thermometer (HA-200E, manufactured by Anritsu Meter Co., Ltd.).

[0371] The kneaded product was cooled and coarsely pulverized to a size of 1 mm or less using a hammer mill to produce a coarsely crushed product. Pulverization and classification were performed with the mechanical pulverizer set at a rotor speed of 10,000 rpm and the FACULTY set at a classification rotor speed of 8,000 rpm and a dispersion rotor speed of 7,200 rpm to produce large-diameter toner particles M1-2 containing polyolefin resin 1.

[0372] The small-sized toner particles F4-2 containing the polyolefin resin 4 and the large-sized toner particles M1-2 containing the polyolefin resin 1 obtained above were mixed at a mass ratio of 1:1. Figure 1 , heat-treated toner particles 6 were obtained by subjecting the toner particles to heat treatment using the surface treatment apparatus shown in .

[0373] The operating conditions involve setting feed rate = 5kg / hr, hot air temperature = 150℃, hot air flow rate = 6m 3 / min, cold air temperature = -5℃, cold air flow = 4m 3 / min, blower air volume = 20m 3 / min and injection air flow rate = 1m 3 / min.

[0374] Then, 1.0 part of hydrophobic silica fine particles (BET: 200 m 2 / g) and 1.0 part of titanium oxide fine particles surface-treated with isobutyltrimethoxysilane (BET: 80 m 2 / g) was mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) for 30 s -1 The mixture was mixed at a rotation speed of 0.05 and a rotation time of 10 minutes to produce Toner 6.

[0375] <Manufacturing Example of Toner 7>

[0376] Colorant 7 is obtained by performing the same operations as in the manufacturing example of colorant 3, except that the polyolefin resin 2 in the manufacturing example of colorant 3 is changed to the polyolefin resin 1, the polyolefin resin 1 is changed to the polyolefin resin 4, and the small-particle colorant particles F1 containing the polyolefin resin 1 and the large-particle colorant particles M4 containing the polyolefin resin 4 are mixed.

[0377] <Manufacturing Example of Toner 8>

[0378] Colorant 8 is obtained by performing the same operations as in the manufacturing example of colorant 3, except that the polyolefin resin 1 in the manufacturing example of colorant 3 is replaced by the polyolefin resin 3, and the small-particle colorant particles F2 containing the polyolefin resin 2 and the large-particle colorant particles M3 containing the polyolefin resin 3 are mixed.

[0379] <Manufacturing Example of Toner 9>

[0380] Toner 9 is obtained by performing the same operations as in the manufacturing example of toner 3, except that the polyolefin resin 2 in the manufacturing example of toner 3 is replaced by the polyolefin resin 5, and the small-particle colorant particles F5 containing the polyolefin resin 5 and the large-particle colorant particles M1 containing the polyolefin resin 1 are mixed.

[0381] <Manufacturing Example of Toner 10>

[0382] Toner 10 is obtained by performing the same operation as in the production example of Toner 1 except that the polyolefin-based resin 1 in the production example of Toner 1 is changed to the polyolefin-based resin 6.

[0383] The obtained toners 1 to 10 were each divided into roughly two equal parts based on the number, i.e., into a large particle size side and a small particle size side (the difference in the number of particles was 4% or less) using an Elbow-jet of an inertial classification system (manufactured by Nittetsu Mining Co., Ltd.) to obtain a first group and a second group, and then each toner was evaluated.

[0384] The operating conditions of the Elbow Jet were adjusted to a feed rate of 5 kg / hr, a fine powder classification margin of 10 to 15 mm, and a coarse powder classification margin that was closed as much as possible. This allowed each toner to be divided into two approximately equal groups: a first group of large-particle toners and a second group of small-particle toners. The results are shown in Table 2.

[0385] [Table 2]

[0386]

[0387] In the table, the sulfonic acid group content represents the content ratio (mass %) of the monomer unit containing a sulfonic acid group in the vinyl polymer of the polyolefin resin having a sulfonic acid group. Furthermore, D50 represents the median diameter (μm) of the toner based on number, and the span value represents the span value obtained according to Expression (2).

[0388] <Production Example of Magnetic Core Particles 1>

[0389] -Step 1 (weighing and mixing step):

[0390]

[0391]

[0392] The above materials were weighed to obtain the above composition ratio. Thereafter, the materials were pulverized and mixed in a dry vibration mill using stainless steel beads having a diameter of 1 / 8 inch for 5 hours.

[0393] - Step 2 (pre-calcination step):

[0394] The obtained pulverized product was formed into pellets of approximately 1 mm square using a roller mill. The pellets were passed through a vibrating sieve with a sieve size of 3 mm to remove coarse powder, and then a vibrating sieve with a sieve size of 0.5 mm to remove fine powder. Pre-baked ferrite was prepared by calcining at 1000° C. for 4 hours in a nitrogen atmosphere (oxygen concentration: 0.01% by volume) using a burner-type calcining furnace. The resulting pre-baked ferrite had the following composition.

[0395] (MnO) a (MgO) b (SrO) c (Fe2O3) d

[0396] In the above formula, a=0.257, b=0.117, c=0.007, and d=0.393.

[0397] -Step 3 (crushing step):

[0398] After the pre-baked ferrite was crushed to about 0.3 mm with a crusher, 30 parts of water was added to 100 parts of the pre-baked ferrite, and pulverized for 1 hour using a wet ball mill with zirconia beads having a diameter of 1 / 8 inch. The resulting slurry was pulverized for 4 hours using a wet ball mill with alumina beads having a diameter of 1 / 16 inch to obtain a ferrite slurry (finely pulverized product of the pre-baked ferrite).

[0399] - Step 4 (granulation step):

[0400] A total of 1.0 part of ammonium polycarboxylate as a dispersant and 2.0 parts of polyvinyl alcohol as a binder were added to the ferrite slurry relative to 100 parts of the pre-baked ferrite, and then granulated into spherical particles using a spray dryer (manufacturer: Ohkawara Kakohki Co., Ltd.). The resulting particles were adjusted in particle size and then heated at 650°C for 2 hours using a rotary kiln to remove organic components of the dispersant and binder.

[0401] - Step 5 (calcination step):

[0402] To control the calcination atmosphere, the temperature was raised from room temperature to 1300° C. over 2 hours in an electric furnace under a nitrogen atmosphere (oxygen concentration of 1.00 vol%), and then calcined at 1150° C. for 4 hours. The temperature was then lowered to 60° C. over 4 hours, the nitrogen atmosphere was returned to an air atmosphere, and the pellets were removed at a temperature below 40° C.

[0403] -Step 6 (Screening Step):

[0404] After decomposing the aggregated particles, the low magnetic product was cut by magnetic separation, and coarse particles were removed by sieving using a mesh having a mesh size of 250 μm to obtain magnetic core particles 1 having a 50% particle size (D50) of 37.0 μm based on volume distribution.

[0405] <Preparation of coating resin 1>

[0406]

[0407] The cyclohexyl methacrylate monomer, methyl methacrylate monomer, methyl methacrylate macromonomer, toluene, and methyl ethyl ketone (Methyl Ethyl Ketone) of the above materials were placed in a four-necked separable flask equipped with a reflux condenser, a thermometer, a nitrogen inlet tube, and a stirrer. Nitrogen was introduced to create a sufficient nitrogen atmosphere. The flask was then heated to 80°C, azobisisobutyronitrile was added, and polymerization was carried out while reflux for 5 hours. Hexane was added to the resulting reaction product to cause precipitation of a copolymer. The resulting precipitate was isolated by filtration and then vacuum-dried to produce Coating Resin 1.

[0408] Then, 30 parts of the coating resin 1 was dissolved in 40 parts of toluene and 30 parts of methyl ethyl ketone to produce a polymer solution 1 (solid: 30% by mass).

[0409] <Preparation of Coating Resin Solution 1>

[0410] Polymer solution 1 (resin solid content concentration: 30% by mass) 33.3% by mass

[0411] Toluene 66.4 mass%

[0412] Carbon black (Regal 330; manufactured by Cabot Corporation) 0.3 mass%

[0413] (Primary particle size 25nm, nitrogen adsorption specific surface area 94m 2 / g, DBP oil absorption 75ml / 100g)

[0414] The above materials were dispersed for 1 hour by a paint shaker using zirconia beads having a diameter of 0.5 mm. The resulting dispersion was filtered by a 5.0 μm membrane filter to obtain a coating resin solution 1.

[0415] <Manufacturing Example of Magnetic Carrier 1>

[0416] Resin coating steps:

[0417] The magnetic core particles 1 and the coating resin solution 1 are loaded into a vacuum degassing kneader maintained at room temperature (relative to 100 parts of the magnetic core particles 1, the loading amount of the coating resin solution 1 is 2.5 parts in terms of the resin component). After loading, the components are stirred at a rotation speed of 30 rpm for 15 minutes. After the solvent evaporates to a certain extent (80% by mass), the temperature is raised to 80°C while mixing under reduced pressure, and toluene is distilled off within 2 hours, and then cooled. The obtained magnetic carrier is subjected to magnetic separation to fractionate low magnetic products, sieved by a sieve with a sieve size of 70 μm, and classified with a wind classifier to obtain a magnetic carrier 1 having a 50% particle size (D50) of 38.2 μm based on volume distribution.

[0418] <Manufacturing Example of Two-Component Developer 1>

[0419] Two-component developer 1 was obtained by mixing 92.0 parts of magnetic carrier 1 and 8.0 parts of toner 1 in a V-type mixer (V-20, manufactured by Swishing Enterprise Co., Ltd.).

[0420] <Manufacturing Examples of Two-Component Developers 2 to 10>

[0421] Two-component developers 2 to 10 were obtained by performing the same operations as in the production example of the two-component developer 1, except that the toner 1 was changed to the toners 2 to 10, respectively.

[0422] <Example 1>

[0423] The following evaluations were conducted using the two-component developer 1. A modified version of the image RUNNER ADVANCE C5560 digital commercial printer manufactured by Canon Inc. was used as the image forming apparatus. The apparatus was modified so that the fixing temperature, process speed, and DC voltage V of the developer carrier could be freely set. DC , the charging voltage V of the electrostatic latent image bearing member D and laser power.

[0424] In order to evaluate image output, an FFh image (solid image) having a desired image ratio is output, and V is adjusted so that the amount of toner on the FFh image is desired. DC, VD and laser power, and then the following evaluation was performed. The FFh value herein represents a value obtained by displaying 256 grayscales in hexadecimal notation, where 00h is the first of the 256 grayscales (white background portion) and FFh is the 256th grayscale (solid portion).

[0425] [Fog suppression]

[0426] The two-component developer 1 was placed in the black developing device of the above-mentioned image forming apparatus, an evaluation image was output under the following conditions, and suppression of fogging was evaluated.

[0427] Paper: CS-680 (68.0g / m 2 ) (Manufactured by Canon Marketing Japan Inc.)

[0428] Evaluation image: 00h image on the entire surface of the above-mentioned A4 paper

[0429] Vback: 150V (based on the DC voltage V of the developer carrier) DC , the charged voltage V of the electrostatic latent image bearing member D , and laser power)

[0430] Test environment: High temperature and high humidity environment (temperature 30°C / humidity 80% RH (hereinafter referred to as "H / H"))

[0431] Fixing temperature: 170℃

[0432] Processing speed: 377mm / sec

[0433] The fogging value defined below is used as an evaluation index for fogging suppression.

[0434] First, the average reflectivity Ds (%) of the evaluation paper before output was measured using a reflectometer (REFLECTOMETER MODEL TC-6DS: manufactured by Tokyo Denshoku Co., Ltd.). The average reflectivity Dr (%) of the output evaluation paper was measured. The value calculated according to the following expression was considered the fogging value. The obtained fogging value was evaluated according to the following evaluation criteria. A result of C or higher was considered to have achieved the effects of the present invention.

[0435] Fogging value = Dr (%) - Ds (%)

[0436] (Evaluation Criteria)

[0437] A: Fogging value is less than 0.3%

[0438] B: Fogging value is 0.3% or more and less than 0.5%

[0439] C: Fogging value is 0.5% or more and less than 0.8%

[0440] D: Fogging value is 0.8% or more and less than 1.2%

[0441] E: Fogging value is 1.2% or more

[0442] [Transferability]

[0443] Paper: GF-C081(81.0g / m 2 ) (Manufactured by Canon Marketing Japan Inc.)

[0444] Toner loading on solid images: 0.35 mg / cm 2

[0445] Primary transfer current: 30μA

[0446] Test environment: Normal temperature and humidity environment: (temperature 23℃ / humidity 50%RH)

[0447] Processing speed: 377mm / sec

[0448] The two-component developer 1 was placed in the cyan developing device of the above-mentioned image forming apparatus and evaluated as follows.

[0449] The untransferred toner remaining on the photosensitive member after the primary transfer and the toner before the primary transfer were attached and peeled off using a polyester transparent adhesive tape. The peeled adhesive tape was attached to paper, and the density was measured using a spectrophotometer 500 series (manufactured by X-Rite, Inc.).

[0450] The transfer efficiency was calculated from the image density before primary transfer and the transfer residual image density obtained as described above based on the following expression; the transfer efficiency was then evaluated based on the following evaluation criteria: For results of C and better, it is considered that the effect of the present invention is achieved.

[0451] Transfer efficiency (%) =

[0452] (Image density before primary transfer - transfer residual image density) / (Image density before primary transfer) × 100

[0453] (Evaluation Criteria)

[0454] A: Transfer efficiency: more than 90.0%

[0455] B: Transfer efficiency: 85.0% or more and less than 90.0%

[0456] C: Transfer efficiency: 80.0% or more and less than 85.0%

[0457] D: Transfer efficiency: less than 80.0%

[0458] [Image Density]

[0459] Paper: GF-C081(81.0g / m 2 ) (Manufactured by Canon Marketing Japan Inc.)

[0460] Vcontrast (based on the DC voltage V DC , the charged voltage V of the electrostatic latent image bearing member D , and laser power adjustment): 350V

[0461] Evaluation image: 2cm×5cm image placed in the center of the above A4 paper

[0462] Test environment: Normal temperature and humidity environment: temperature 23°C / humidity 50% RH (hereinafter referred to as "N / N")

[0463] Fixing temperature: 170℃

[0464] Processing speed: 377mm / sec

[0465] The above evaluation image was output, and the image density was evaluated using the image density value as an evaluation index. The image density of the center portion was measured using an X-Rite color reflection densitometer (500 series: manufactured by X-Rite Inc.). The image density values ​​obtained were evaluated according to the following evaluation criteria. For results of C and better, it was considered that the effects of the present invention were achieved.

[0466] (Evaluation Criteria)

[0467] A: Image density value is 1.35 or more

[0468] B: Image density value is 1.30 or more and less than 1.35

[0469] C: Image density value is 1.25 or more and less than 1.30

[0470] D: Image density value is less than 1.25

[0471] [Image Quality]

[0472] Paper: GF-C081(81.0g / m 2 ) (Manufactured by Canon Marketing Japan Inc.)

[0473] Vcontrast (based on the DC voltage V DC , the charged voltage V of the electrostatic latent image bearing member D, and laser power adjustment): 300V

[0474] Evaluation image: A vertical line image with 1 dot and 1 space placed on the A4 paper mentioned above

[0475] Test environment: Normal temperature and humidity environment: temperature 23°C / humidity 50% RH (hereinafter referred to as "N / N")

[0476] Fixing temperature: 170℃

[0477] Processing speed: 377mm / sec

[0478] The evaluation image described above was output and its quality was evaluated. The image quality evaluation indicator used herein was the Blur value (a numerical value indicating the blur of lines as defined in ISO 13660). The Blur value was measured using a personal IAS (Image Analysis System) (manufactured by QEA Inc.). The obtained Blur value was evaluated according to the following evaluation criteria. Results of C or higher were considered to have achieved the effects of the present invention.

[0479] (Evaluation Criteria)

[0480] A: Blur value is less than 35μm

[0481] B: Blur value is greater than 35μm and less than 38μm

[0482] C: Blur value is greater than 38μm and less than 41μm

[0483] D: Blur value is 41μm or more

[0484] <Examples 2 to 6 and Comparative Examples 1 to 4>

[0485] The evaluation results are given in Table 3.

[0486] [Table 3]

[0487]

[0488] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A two-component developer, characterized in that: Contains toner and magnetic carrier, The toner contains toner particles, The toner particles contain a binder resin comprising a polyester resin, and A polyolefin resin having a sulfonic acid group, wherein The polyester resin is a copolymer of bisphenol and its derivatives represented by formula (A), terephthalic acid, adipic acid and trimellitic acid, In formula (A), R is an ethylene group or a propylene group, x and y are each an integer greater than or equal to 0, and the average value of x+y is 0 to 10; The polyolefin-based resin having a sulfonic acid group is a polymer in which a vinyl-based polymer is bonded to polypropylene; The vinyl polymer is produced by polymerization of styrene, 2-acrylamide-2-methylpropane sulfonic acid, cyclohexyl methacrylate and butyl acrylate; The content ratio of the monomer unit containing a sulfonic acid group in the vinyl polymer is 1.0% to 20.0% by mass; When the toner is classified into two groups, a first group containing toner with a large particle size and a second group containing toner with a small particle size, using a classifier of an inertial classification system so that the number of toner particles in the first group is substantially equal to the number of toner particles in the second group, Satisfies expression (1): 1.10≤(As / Bs) / (Al / Bl)≤2.00 … (1) wherein As represents the sulfonic acid group at 1130 cm-1 attributed to the polyolefin resin in the FT-IR spectrum of the second group obtained by measuring the second group according to the ATR method using Ge as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak within the range; Bs represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum of the second group measured by the ATR method using diamond as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak within the range; Al represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum obtained by measuring the first group according to the ATR method using Ge as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensities of the maximum absorption peaks within the range of ; and B1 represents the wavelength at 1130 cm-1 attributable to the sulfonic acid group contained in the polyolefin resin in the FT-IR spectrum obtained by measuring the first group according to the ATR method using diamond as the ATR crystal and setting the infrared light incident angle to 45°. -1 to 1170cm -1 The intensity of the maximum absorption peak in the range of 1713 cm-1 is attributed to the carbonyl group in the polyester resin. -1 to 1723cm -1 The ratio of the intensity of the maximum absorption peak within the range; The toner has a number-based median diameter D50 of 3.0 μm to 6.0 μm; and The toner has a span value obtained according to the following expression (2) of 1.1 to 2.0: Span value = (D90-D10) / D50…(2) D90 is the particle size of the toner when the cumulative number of particles starting from the smaller particle size is 90%, and D10 is the particle size of the toner when the cumulative number of particles starting from the smaller particle size is 10%.

2. The two-component developer according to claim 1, wherein As, Bs, Al, and Bl satisfy the following expression (1'): 1.50≤(As / Bs) / (Al / Bl)≤2.00…(1').

3. The two-component developer according to claim 1 or 2, wherein the monomer unit having a sulfonic acid group is represented by the following formula (C): In formula (C), R 1 represents a hydrogen atom or a methyl group; and X represents a C1 to C8 linear or branched alkylene group. 4 . The two-component developer according to claim 1 , wherein the polyester resin is a non-crystalline polyester resin. 5 . The two-component developer according to claim 1 , wherein a content ratio of the polypropylene in the polyolefin-based resin having a sulfonic acid group is 5.0% by mass to 20.0% by mass.

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