JP2018041038A - Toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development excellent in image density uniformity of a halftone image output after images partially having a high image density portion are continuously output.SOLUTION: A toner for electrostatic charge image development has at least a binder resin, and toner particles containing a colorant and an external additive, where in number particle size distribution of the toner particles, a ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is 5% or more and 60% or less with respect to the total of the toner particles, a ratio of the toner particles having a particle size of more than 2 μm and 50 μm or less is 40% or more and 95% or less with respect to the total of the toner particles, and in volume particle size distribution of the toner particles, a ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is 0.6% or more and 10% or less with respect to the total of the toner particles, and a ratio of the toner particles having a particle size of more than 2 μm and 50 μm or less is 90% or more and 99.4% or less with respect to the total of the toner particles.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

  In electrophotographic image formation, toner is used as an image forming material.For example, toner particles containing a binder resin, a release agent, and a colorant, and an external additive externally added to the toner particles; Many toners containing toner are used.

Examples of conventional toners include toners described in Patent Documents 1 to 3.
In Patent Document 1, in the particle size distribution displayed by the number distribution, there are peaks in the respective particle size distribution portions of less than 6.35 μ and 6.35 μ or more, and the peak value of 6.35 μ or less is 6.35 μ or more. For electrostatic charge image development, characterized in that it is smaller than the peak value and 0.5% or less is 1% or less, 6.35μ or less is 15% or less, and 20.2μ or more is 0.5% or less in the number distribution. Toner is described.
Patent Document 2 discloses a developer comprising a toner and a carrier, wherein the toner is a toner containing at least colored particles containing a binder resin and a coloring material, resin fine particles and inorganic fine particles, and the resin. The fine particles are melamine / formaldehyde condensation polymer resin fine particles having a volume average particle size of 0.01 to 1.0 μm, the inorganic fine particles have a volume average particle size of 0.01 to 0.20 μm, and the volume average particle size distribution is The standard deviation (σ) is 10 ≦ σ ≦ 30, and the carrier includes at least a mixture or copolymer of an alicyclic methacrylate ester or a chain methacrylate ester homopolymer on the magnetic particles, inorganic fine particles, A developer characterized in that it is a negatively chargeable carrier coated with a resin layer made of is described.
Patent Document 3 describes a developing toner in which the toner particle size distribution has two peaks above and below the toner average particle size of 8 μm as a boundary.

Japanese Patent No. 2663006 JP 9-006039 A JP-A-6-059494

  The problem to be solved by the present invention is that the ratio of toner particles having a particle size of 0.5 μm or more and 2 μm or less is less than 5% or 60% in the toner particle number distribution. Or in the volume particle size distribution of the toner particles, the ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is less than 0.6% or more than 10% with respect to the whole toner particles Compared to the case, it is an object to provide a toner for developing an electrostatic charge image that suppresses a decrease in image density uniformity of a halftone image output after continuously outputting an image having a high image density portion in part.

  The above problem is solved by the following means.

The invention according to claim 1
A toner particle containing at least a binder resin and a colorant, and an external additive; in the number particle size distribution of the toner particles, a ratio of toner particles having a particle size of 0.5 μm to 2 μm The ratio of toner particles having a particle diameter of 5% or more and 60% or less and exceeding 2 μm and 50 μm or less is 40% or more and 95% or less with respect to the whole toner particles. The ratio of the toner particles having a particle diameter of 0.5 μm or more and 2 μm or less is 0.6% or more and 10% or less with respect to the whole toner particles, and the ratio of the toner particles having a particle diameter of more than 2 μm and 50 μm or less is the whole toner particles. On the other hand, it is an electrostatic charge image developing toner that is 90% or more and 99.4% or less.

The invention according to claim 2
2. The electrostatic image development according to claim 1, wherein the number particle size distribution of the toner particles has at least one peak in each of a region having a particle size of 0.5 μm to 2 μm and a region having a particle size of more than 2 μm and 8 μm or less. Toner.

The invention according to claim 3
3. The electrostatic image developing toner according to claim 1, wherein a volume average particle diameter of the toner particles is 4 μm or more and 10 μm or less.

The invention according to claim 4
4. The electrostatic image developing toner according to claim 1, wherein the toner particles having a particle size of 0.5 μm to 2 μm have an average circularity of 0.940 to 0.995. 5. .

The invention according to claim 5
The toner particles having a particle size of 0.5 μm or more and 2 μm or less have an average circularity of C1 and an average circularity of all toner particles of C2, and 0.005 ≦ C1−C2 ≦ 0.050. 5. The toner for developing an electrostatic charge image according to any one of 4 above.

The invention according to claim 6
An electrostatic charge image developer comprising a carrier and the electrostatic charge image developing toner according to any one of claims 1 to 5.

The invention according to claim 7 provides:
The electrostatic charge image developer according to claim 6, wherein the carrier has a number average particle diameter of 15 μm or more and 70 μm or less.

The invention according to claim 8 provides:
A toner cartridge that accommodates the electrostatic image developing toner according to claim 1 and is detachable from an image forming apparatus.

The invention according to claim 9 is:
A developing means for containing the electrostatic charge image developer according to claim 6 or 7 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer, It is a process cartridge that can be attached to and detached from the image forming apparatus.

The invention according to claim 10 is:
8. The image holding member, a charging unit that charges the surface of the image holding member, an electrostatic charge image forming unit that forms an electrostatic charge image on the charged surface of the image holding member, and An electrostatic charge image developer is accommodated, and with the electrostatic charge image developer, developing means for developing the electrostatic charge image formed on the surface of the image carrier as a toner image, and formed on the surface of the image carrier. An image forming apparatus comprising: a transfer unit that transfers a toner image to the surface of a recording medium; and a fixing unit that fixes the toner image transferred to the surface of the recording medium.

The invention according to claim 11 is:
A charging step for charging the surface of the image carrier, an electrostatic charge image forming step for forming an electrostatic image on the charged surface of the image carrier, and an electrostatic image developer according to claim 6 or 7. A developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image, a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium, and the recording A fixing step of fixing the toner image transferred to the surface of the medium.

According to the first aspect of the present invention, in the number particle size distribution of the toner particles, the ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is less than 5% or 60% with respect to the whole toner particles. Or in the volume particle size distribution of the toner particles, the ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is less than 0.6% or more than 10% with respect to the whole toner particles As compared with the case, there is provided an electrostatic charge image developing toner that suppresses a decrease in image density uniformity of a halftone image output after continuously outputting an image having a high image density portion in part.
According to the second aspect of the present invention, in the number particle size distribution of the toner particles, an image having a high image density portion in part compared to the case where there is one peak in a region having a particle size of 0.5 μm or more and 8 μm or less. Provided is a toner for developing an electrostatic charge image that further suppresses a reduction in image density uniformity of a halftone image output after continuous output.
According to the third aspect of the present invention, compared to the case where the volume average particle diameter of the toner particles is less than 4 μm, the image density of the halftone image output after continuously outputting an image having a high image density portion in part is uniform. There is provided a toner for developing an electrostatic image that further suppresses the deterioration of the property.
According to the invention of claim 4, continuous output of an image having a high image density portion in part compared to the case where the average circularity of toner particles having a particle size of 0.5 μm or more and 2 μm or less is less than 0.940. An electrostatic charge image developing toner that further suppresses a decrease in image density uniformity of a halftone image that is output thereafter is provided.
According to the invention of claim 5, when the average circularity of toner particles having a particle diameter of 0.5 μm or more and 2 μm or less is C1, and the average circularity of all toner particles is C2, C1-C2> 0.050. As compared with the case, there is provided an electrostatic image developing toner that further suppresses a reduction in image density uniformity of a halftone image output after continuously outputting an image having a high image density portion in part.

According to the invention according to claim 6 or 7, in the number particle size distribution of the toner particles of the toner, the ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is less than 5% with respect to the whole toner particles, Or the ratio of toner particles having a particle size of 0.5 μm or more and 2 μm or less in the volume particle size distribution of the toner particles is less than 0.6% with respect to the whole toner particles, or An electrostatic charge image developer that suppresses a decrease in image density uniformity of a halftone image that is output after continuously outputting an image having a high image density portion in part as compared with the case of exceeding 10% is provided.
According to the invention of claim 8, 9, 10 or 11, in the number particle size distribution of the toner particles of the toner, the ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is less than 5% with respect to the whole toner particles. Or over 60%, or in the volume particle size distribution of the toner particles, the ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is less than 0.6% with respect to the whole toner particles. Or a toner cartridge, a process cartridge, and an image formation that suppresses a decrease in image density uniformity of a halftone image that is output after continuously outputting an image having a high image density portion in part compared to a case where it exceeds 10% An apparatus or image forming method is provided.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment. In the number particle size distribution of toner particles, it is a schematic diagram in the case where one peak is shown in each of a region having a particle size of 0.5 μm or more and 2 μm or less and a region having a particle size of more than 2 μm and 8 μm or less.

Hereinafter, the present embodiment will be described.
In addition, description with "mass part" and "mass%" is synonymous with "weight part" and "weight%", respectively.

<Toner for electrostatic image development>
The electrostatic image developing toner according to the exemplary embodiment (also simply referred to as “toner”) includes at least a binder resin, toner particles containing a colorant, and an external additive, and the number of the toner particles. In the particle size distribution, the ratio of toner particles having a particle diameter of 0.5 μm or more and 2 μm or less is 5% or more and 60% or less with respect to the whole toner particles, and the ratio of toner particles having a particle diameter of more than 2 μm and 50 μm or less is The ratio of the toner particles having a particle diameter of 0.5 μm or more and 2 μm or less in the volume particle size distribution of the toner particles is 0.6% or more and 10% with respect to the whole toner particles. The ratio of toner particles having a particle diameter of more than 2 μm and not more than 50 μm is 90% or more and 99.4% or less with respect to the whole toner particles.

  With the electrostatic charge image developing toner according to this embodiment, the above-described configuration suppresses a reduction in image density uniformity of a halftone image output after an image having a high image density portion in part is continuously output. The reason for this is not clear, but is presumed to be as follows.

In electrophotographic image formation, an image having a high image density portion in part (specifically, for example, the right half of the image is a solid image (image density 100%) and the left half is blank paper (image density). If the halftone image is output after the image (0%) is output continuously, the image density uniformity may decrease. This is because by continuously outputting an image having a high image density part in part, a large amount of toner is consumed in the high image density part, and the external additive moves from the toner to the carrier of the part, and the carrier of the other part More external additive remains. For this reason, a bias occurs in the external additive adhesion state of the carrier, and when a halftone image is output, the developability of the toner changes between the high image density portion and the other portion, thereby causing a difference in image density. Occurs, and the image density uniformity is reduced.
Further, in a high humidity environment (for example, 90% RH), the image density uniformity is likely to be reduced. The reason for this is considered to be that the adhesion between the carrier and the toner is increased due to the liquid crosslinking force, so that the influence of the non-electrostatic adhesion on the adhesion of the external additive to the carrier is increased.

  In the present embodiment, the high image density portion refers to a portion having an image density of 70% or more, for example, a portion having an image density of 100%, a so-called solid image portion. In the present embodiment, a halftone image refers to a halftone image portion having an image density of 20% to 50%.

  In the electrostatic charge image developing toner according to the exemplary embodiment, as described above, in the number particle size distribution and the volume particle size distribution, the ratio of toner particles having a particle size of 0.5 μm or more and 2 μm or less is defined within a specific range. It shows that the toner for developing an electrostatic charge image according to the embodiment has more toner particles having a particle diameter of 0.5 μm or more and 2 μm or less than the conventional toner.

Part of the external additive adhering to the toner particles moves to the surface of the carrier by contact with the carrier. The carrier surface has irregularities, and when the external additive attached to the carrier moves to the concave portion on the surface, it adheres again to a toner having a normal particle size, for example, a volume average particle size of 4 μm to 10 μm. Hateful.
On the other hand, when small toner particles having a diameter of 2 μm or less are present, when the carrier collides with the small toner particles, the small toner particles follow the irregularities on the surface of the carrier, and the external additive and the small toner particles present in the concave portions of the carrier By re-adhering, the external additive present in the concave portion of the carrier surface is removed after the image having a high image density portion in part is continuously output.
Therefore, the bias of the external additive adhesion state in the carrier is eliminated, the occurrence of the image density difference is suppressed, and the image density uniformity of the halftone image output after continuously outputting the image having a high image density part in part ( Hereinafter, a decrease in the “image density uniformity” is also suppressed.

  Details of the electrostatic image developing toner according to this embodiment will be described below.

In this embodiment, the number particle size distribution and volume particle size distribution of toner particles are measured by the following method.
In order to measure the characteristics of the toner for developing an electrostatic image with respect to the toner particles, an external additive is separated from the toner particles by pretreatment as necessary.
First, 30 ml of ion-exchanged water is put into a 100 ml beaker, and 2 drops of a surfactant (Wako Pure Chemical Industries, Ltd .: Contaminone) is dropped as a dispersant. 20 mg of the toner to be measured is put in this liquid, A toner particle dispersion for measurement is prepared by dispersing for 3 minutes by ultrasonic dispersion.
Using the obtained toner particle dispersion and a flow type analyzer FPIA-3000 (manufactured by Sysmex Corporation), 50,000 toner particles are measured in a particle size measurement range of 0.5 μm to 50 μm. This system employs a method in which particles dispersed in water or the like are measured by a flow image analysis method. The sucked particle suspension is guided to a flat sheath flow cell, and a sample flow is formed by the sheath liquid. The By irradiating the sample stream with stroboscopic light, the passing particles are captured as a still image by the CCD camera through the objective lens. The captured particle image is subjected to two-dimensional image processing to calculate an equivalent circle diameter, and the number particle size distribution and the volume particle size distribution are measured.

In the electrostatic charge image developing toner according to the exemplary embodiment, the ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is 5% or more and 60% or less of the whole toner particles in the number particle size distribution of the toner particles. From the viewpoint of image density uniformity, it is preferably 8% or more and 50% or less, more preferably 10% or more and 40% or less, and particularly preferably 12% or more and 35% or less.
The toner for developing an electrostatic charge image according to the exemplary embodiment has a toner particle number distribution in which the ratio of toner particles having a particle diameter of more than 2 μm and not more than 50 μm is 40% or more and 95% or less with respect to the whole toner particles. From the viewpoint of image density uniformity, it is preferably 50% or more and 92% or less, more preferably 60% or more and 90% or less, and particularly preferably 65% or more and 88% or less.

In the toner for developing an electrostatic charge image according to the exemplary embodiment, in the volume particle size distribution of the toner particles, the ratio of the toner particles having a particle size of 0.5 μm to 2 μm is 0.6% to 10% with respect to the whole toner particles. From the viewpoint of image density uniformity, it is preferably 0.8% or more and 8% or less, more preferably 1% or more and 7% or less, and particularly preferably 2% or more and 6% or less. .
Further, in the toner for developing an electrostatic charge image according to the exemplary embodiment, in the volume particle size distribution of the toner particles, the ratio of the toner particles having a particle size of more than 2 μm and 50 μm or less is 90% or more and 99.4% with respect to the whole toner particles. From the viewpoint of image density uniformity, it is preferably 92% or more and 99.2% or less, more preferably 93% or more and 99% or less, and particularly preferably 94% or more and 98% or less. preferable.

The toner for developing an electrostatic charge image according to the exemplary embodiment has a particle size distribution of toner particles in a region having a particle size of 0.5 μm to 2 μm and a region having a particle size of more than 2 μm and 8 μm or less from the viewpoint of image density uniformity. Each preferably has at least one peak, and more preferably has one peak in each of a region having a particle size of 0.5 μm or more and 2 μm or less and a region having a particle size of more than 2 μm and 8 μm or less.
The peak in the number particle size distribution of the toner particles is a peak in the frequency distribution.

The volume average particle diameter (D50v) of the toner particles in the electrostatic image developing toner according to this embodiment is preferably 2 μm or more and 15 μm or less, more preferably 4 μm or more and 10 μm or less, and more preferably 4 μm or more from the viewpoint of image density uniformity. 8 μm or less is particularly preferable.
The various average particle diameters and various particle size distribution indices of the toner particles in the present embodiment are calculated from the number particle size distribution and the volume particle size distribution measured using FPIA-3000 (manufactured by Sysmex Corporation) as described above. The
For the particle size range (channel) divided based on the measured particle size distribution, draw the cumulative distribution from the small diameter side for the volume and number, respectively, and the particle size to be 50% is the volume average particle size D50v, the cumulative number The average particle diameter is defined as D50p.

The average circularity of the toner particles in the toner for developing an electrostatic charge image according to the exemplary embodiment is preferably 0.88 or more and 1.00 or less, and 0.90 or more and 0.998 or less from the viewpoint of image density uniformity. More preferably, it is 0.940 or more and 0.995 or less.
In the electrostatic image developing toner according to this embodiment, from the viewpoint of image density uniformity, the average circularity of toner particles having a particle size of 0.5 μm or more and 2 μm or less is C1, and the average circularity of all toner particles is C2. It is preferable that 0.005 ≦ C1-C2 ≦ 0.050.

Note that the average circularity of the toner particles in the present embodiment is measured by FPIA-3000 manufactured by Simex, which was used for measurement of various particle size distribution indexes. Regarding the circularity, 50,000 or more images are analyzed, and the average circularity is obtained by statistical processing.
Formula: Circularity = circle equivalent diameter perimeter / perimeter = [2 × (Aπ) ^1/2 ] / PM
In the above formula, A represents the projected area, and PM represents the perimeter.
In addition, HPF mode (high resolution mode) was used for the measurement, and the dilution factor was 1.0. In analyzing the data, the circularity analysis range was set to a range from 0.40 to 1.00 for the purpose of removing measurement noise.

  The electrostatic image developing toner according to the present exemplary embodiment includes toner particles and an external additive.

(Toner particles)
The toner particles include a binder resin, a colorant, and, if necessary, a release agent and other additives.

-Binder resin-
Examples of the binder resin include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.), (meth) acrylic acid esters (eg, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid). n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (for example, acrylonitrile, Methacrylonitrile, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg, ethylene, propylene, etc.) Emissions, a homopolymer of a monomer such as butadiene) and the like, or a vinyl-based resin composed of these monomers with two or more combinations copolymer.
As the binder resin, for example, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, non-vinyl resin such as modified rosin, a mixture of these with the vinyl resin, or these Examples also include a graft polymer obtained by polymerizing a vinyl monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

A polyester resin is suitable as the binder resin.
Examples of the polyester resin include known amorphous polyester resins. A polyester resin may use a crystalline polyester resin together with an amorphous polyester resin. However, the crystalline polyester resin is preferably used in the range of 2 mass% to 40 mass% (preferably 2 mass% to 20 mass%) with respect to the total binder resin.

The “crystallinity” of the resin means that it has a clear endothermic peak in differential scanning calorimetry (DSC) rather than a stepwise endothermic amount change. Specifically, the temperature rise rate is 10 (° C. / Min) indicates that the half-value width of the endothermic peak is 10 ° C. or less.
On the other hand, “amorphous” of the resin means that the half width exceeds 10 ° C., shows a stepwise endothermic change, or does not show a clear endothermic peak.

-Amorphous polyester resin As an amorphous polyester resin, the condensation polymer of polyhydric carboxylic acid and polyhydric alcohol is mentioned, for example. In addition, as an amorphous polyester resin, a commercial item may be used and what was synthesize | combined may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.) Alicyclic dicarboxylic acids (for example, cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (for example, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or lower (for example, having 1 or more carbon atoms) 5 or less) alkyl esters. Among these, as polyvalent carboxylic acid, aromatic dicarboxylic acid is preferable, for example.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (for example, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (for example, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used together with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower.
The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in the method for determining the glass transition temperature in JIS K 7121-1987 “Method for Measuring Plastic Transition Temperature”. Of “extrapolated glass transition start temperature”.

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably from 5,000 to 1,000,000, more preferably from 7,000 to 500,000.
The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed with a THF solvent using a Tosoh GPC / HLC-8120GPC as a measuring device and a Tosoh column / TSKgel SuperHM-M (15 cm). The weight average molecular weight and the number average molecular weight are calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample from this measurement result.

The amorphous polyester resin can be obtained by a known production method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure in the reaction system is reduced as necessary, and the reaction is performed while removing water and alcohol generated during the condensation.
In addition, when the monomer of the raw material is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added and dissolved as a solubilizing agent. In this case, the polycondensation reaction is performed while distilling off the solubilizer. If there is a monomer with poor compatibility, it is recommended to condense the monomer with poor compatibility with the monomer and the acid or alcohol to be polycondensed in advance before polycondensing with the main component. .

Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. In addition, as a crystalline polyester resin, a commercial item may be used and what was synthesize | combined may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic group is preferable to a polymerizable monomer having an aromatic group.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid. Acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Dibasic acids such as acids), anhydrides thereof, or lower (for example, having 1 to 5 carbon atoms) alkyl esters.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (for example, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.), these Examples thereof include anhydrides and lower (for example, having 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group or a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, linear aliphatic diols having a main chain portion having 7 to 20 carbon atoms). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples include octadecanediol and 1,14-eicosandecanediol. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable as the aliphatic diol.
The polyhydric alcohol may be used in combination with a diol and a trivalent or higher alcohol having a crosslinked structure or a branched structure. Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

  Here, the polyhydric alcohol may have an aliphatic diol content of 80 mol% or more, and preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 55 ° C. or higher and 90 ° C. or lower, and further preferably 60 ° C. or higher and 85 ° C. or lower.
The melting temperature is determined from the “melting peak temperature” described in the method for determining the melting temperature of JIS K7121-1987 “Method for measuring the transition temperature of plastic” from the DSC curve obtained by differential scanning calorimetry (DSC).

  The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

The polyester resin is obtained by a well-known manufacturing method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure in the reaction system is reduced as necessary, and the reaction is performed while removing water and alcohol generated during the condensation.
In addition, when the monomer of the raw material is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added and dissolved as a solubilizing agent. In this case, the polycondensation reaction is performed while distilling off the solubilizer. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polymerized together with the main component. It is good to condense.

  Here, examples of the polyester resin include modified polyester resins in addition to the above-described unmodified polyester resins. The modified polyester resin is a polyester resin in which a bonding group other than an ester bond is present, or a polyester resin in which a resin component different from the polyester resin component is bonded by a covalent bond or an ionic bond. As the modified polyester resin, for example, a polyester resin in which a functional group such as an isocyanate group (also referred to as an isocyanato group) that reacts with an acid group or a hydroxyl group is introduced at a terminal, and a resin in which a terminal is modified by reacting with an active hydrogen compound. Can be mentioned.

  As the modified polyester resin, a urea-modified polyester resin is particularly preferable. By including a urea-modified polyester resin as the binder resin, it is easy to suppress the occurrence of a decrease in image density of an image formed in a region that was a non-image area in the previous image forming cycle. This is because the cross-linking and chemical structure of the urea-modified polyester resin (specifically, the physical properties of the resin resulting from the cross-linking of the urea-modified polyester resin and the chemistry of the affinity between the polar linking group and the polar fatty acid metal salt particles). Characteristics) It is considered that the adhesion between the toner particles, the fatty acid metal salt particles, and the abrasive particles is easily improved by the structure, and the range of the ratio of the liberated amount of the fatty acid metal salt particles and the abrasive particles is easily controlled. Because. In this respect, the content of the urea-modified polyester resin is preferably 5% by mass or more and 50% by mass or less, and more preferably 7% by mass or more and 20% by mass or less with respect to the total binder resin.

  The urea-modified polyester resin is preferably a urea-modified polyester resin obtained by a reaction between a polyester resin having an isocyanate group (polyester prepolymer) and an amine compound (at least one of a crosslinking reaction and an extension reaction). Note that the urea-modified polyester resin may contain a urethane bond together with a urea bond.

  Examples of the polyester prepolymer having an isocyanate group include a polyester which is a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol, and a prepolymer obtained by reacting a polyvalent isocyanate compound with a polyester having active hydrogen. . Examples of the group having active hydrogen in the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like, and alcoholic hydroxyl groups are preferable.

  In the polyester prepolymer having an isocyanate group, examples of the polyvalent carboxylic acid and polyhydric alcohol include the same compounds as the polyvalent carboxylic acid and polyhydric alcohol described in the polyester resin.

Examples of the polyvalent isocyanate compound include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; the polyisocyanates such as phenol derivatives, oximes, caprolactam What blocked with the blocking agent is mentioned.
A polyvalent isocyanate compound may be used individually by 1 type, and may use 2 or more types together.

  The ratio of the polyvalent isocyanate compound is preferably 1/1 or more and 5/1 or less as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester prepolymer having a hydroxyl group. Preferably it is 1.2 / 1 or more and 4/1 or less, More preferably, it is 1.5 / 1 or more and 2.5 / 1 or less. When [NCO] / [OH] is set to 1/1 or more and 5/1 or less, the occurrence of a decrease in image density of an image formed in a region that was a non-image portion in the previous image forming cycle is more easily suppressed. When [NCO] / [OH] is set to 5 or less, a decrease in low-temperature fixability is easily suppressed.

  In the polyester prepolymer having an isocyanate group, the content of the component derived from the polyvalent isocyanate compound is preferably 0.5% by mass or more and 40% by mass or less, more preferably, based on the entire polyester prepolymer having an isocyanate group. 1 mass% or more and 30 mass% or less, More preferably, they are 2 mass% or more and 20 mass% or less. When the content of the component derived from the polyvalent isocyanate is 0.5% by mass or more and 40% by mass or less, the occurrence of a decrease in the image density of the image formed in the non-image area in the previous image formation cycle is further suppressed. It becomes easy to be done. Note that when the content of the component derived from the polyvalent isocyanate is 40% by mass or less, a decrease in low-temperature fixability is easily suppressed.

  The number of isocyanate groups contained per molecule of the polyester prepolymer having isocyanate groups is preferably 1 or more on average, more preferably 1.5 or more and 3 or less, and even more preferably 1.8 or more on average. .5 or less. When the number of isocyanate groups is 1 or more per molecule, the molecular weight of the urea-modified polyester resin after the reaction increases, and the image density of the image formed in the non-image area in the previous image formation cycle is reduced. It becomes easier to be suppressed.

  Examples of the amine compound that reacts with the polyester prepolymer having an isocyanate group include diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, and compounds in which these amino groups are blocked.

Examples of the diamine include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, isophoronediamine, etc. ); Aliphatic diamine (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like.
Examples of the trivalent or higher polyamine include diethylenetriamine and triethylenetetramine.
Examples of amino alcohols include ethanolamine and hydroxyethylaniline.
Examples of amino mercaptans include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of amino acids include aminopropionic acid and aminocaproic acid.
These amino group-blocked ones include ketimine compounds obtained from amine compounds such as diamines, trivalent or higher polyamines, amino alcohols, amino mercaptans, amino acids and ketone compounds (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), Examples include oxazoline compounds.
Of these amine compounds, ketimine compounds are preferred.
An amine compound may be used individually by 1 type, and may use 2 or more types together.

Note that the urea-modified polyester resin is a polyester resin having an isocyanate group (polyester prepolymer) by a stopper that stops at least one of a crosslinking reaction and an extension reaction (hereinafter also referred to as “crosslinking / extension reaction stopper”). It may be a resin in which the molecular weight after the reaction is adjusted by adjusting the reaction with the amine compound (at least one of a crosslinking reaction and an extension reaction).
Examples of the crosslinking / elongation reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The ratio of the amine compound is preferably 1/2 or more and 2 as an equivalent ratio [NCO] / [NHx] of the isocyanate group [NCO] in the polyester prepolymer having an isocyanate group and the amino group [NHx] in the amines. / 1 or less, more preferably 1 / 1.5 or more and 1.5 / 1 or less, and still more preferably 1 / 1.2 or more and 1.2 / 1 or less. When [NCO] / [NHx] is in the above range, the molecular weight of the urea-modified polyester resin after the reaction increases, and the image density of the image formed in the region that was a non-image area in the previous image formation cycle is more likely to occur. It becomes easy to be suppressed.

  The glass transition temperature of the urea-modified polyester resin is preferably 40 ° C. or higher and 65 ° C. or lower, and more preferably 45 ° C. or higher and 60 ° C. or lower. The number average molecular weight (Mn) is preferably 2,500 or more and 50,000 or less, and more preferably 2,500 or more and 30,000 or less. The weight average molecular weight (Mw) is preferably from 10,000 to 500,000, and more preferably from 30,000 to 100,000.

  The content of the binder resin is, for example, preferably 40% by mass to 98% by mass, more preferably 50% by mass to 96% by mass, and more preferably 60% by mass to 94% by mass with respect to the entire toner particles. Further preferred.

-Colorant-
Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmine 6B, Dupont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or acridine, xanthene, , Benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazole, and other dyes Etc.
A colorant may be used individually by 1 type and may use 2 or more types together.

  As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant. A plurality of colorants may be used in combination.

  The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Release agent-
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; and ester waxes such as fatty acid esters and montanic acid esters. And so on. The release agent is not limited to this.

The melting temperature of the release agent is preferably 50 ° C. or higher and 150 ° C. or lower, and more preferably 60 ° C. or higher and 120 ° C. or lower.
Note that the melting temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC) according to “melting peak temperature” described in JIS K 7121-1987 “Method for measuring the melting temperature of plastics”. .

  The content of the release agent is, for example, preferably 1% by mass to 20% by mass and more preferably 3% by mass to 15% by mass with respect to the entire toner particles.

-Other additives-
Examples of other additives include known additives such as a magnetic material, a charge control agent, and inorganic powder. These additives are contained in the toner particles as internal additives.

-Toner particle characteristics-
The toner particles may be toner particles having a single layer structure, or toner particles having a so-called core / shell structure composed of a core (core particle) and a coating layer (shell layer) covering the core. May be.
Here, the core / shell structure toner particles include, for example, a core portion including a binder resin and, if necessary, other additives such as a colorant and a release agent, and a binder resin. It is good to be comprised with the comprised coating layer.

(External additive)
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. Examples include SiO ₂ , K ₂ O. (TiO ₂ ) _n , Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO _{4 and the} like.

The surface of the inorganic particles as an external additive is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is usually, for example, from 1 part by weight to 40 parts by weight with respect to 100 parts by weight of the inorganic particles.

  Examples of external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, fluorine-based high molecular weight substances). Particle) and the like.

  The external addition amount of the external additive is preferably 0.01% by mass or more and 8% by mass or less, and more preferably 0.01% by mass or more and 6% by mass or less with respect to the toner particles.

<Toner production method>
Next, a toner manufacturing method according to this embodiment will be described.
The toner according to the exemplary embodiment can be obtained by externally adding an external additive to the toner particles after the toner particles are manufactured.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method) and a wet production method (for example, an aggregation coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The production method of the toner particles is not particularly limited, and a known production method is adopted.
Among these, it is preferable to obtain toner particles by an aggregation and coalescence method.

Specifically, for example, when toner particles are produced by an aggregation coalescence method,
A step of preparing a resin particle dispersion in which resin particles to be a binder resin are dispersed (resin particle dispersion preparation step), and a resin particle dispersion (after mixing other particle dispersions as necessary) In the dispersion), the resin particles (other particles as necessary) are aggregated to form aggregated particles (aggregated particle formation step), and the aggregated particle dispersion in which the aggregated particles are dispersed is heated. Then, toner particles are manufactured through a process of fusing and coalescing the aggregated particles to form toner particles (fusing and coalescing process).

Details of each step will be described below.
In the following description, a method of obtaining toner particles containing a colorant and a release agent will be described. However, the colorant and the release agent are used as necessary. Of course, you may use other additives other than a coloring agent and a mold release agent.

-Preparation step of resin particle dispersion-
First, together with a resin particle dispersion in which resin particles serving as a binder resin are dispersed, for example, a colorant particle dispersion in which colorant particles are dispersed and a release agent particle dispersion in which release agent particles are dispersed are prepared. To do.

  Here, the resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

Examples of the dispersion medium used for the resin particle dispersion include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together.

Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an anionic surfactant and a cationic surfactant are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
Surfactant may be used individually by 1 type and may use 2 or more types together.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion include a general dispersion method such as a rotary shear homogenizer, a ball mill having media, a sand mill, and a dyno mill. Depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion using, for example, a phase inversion emulsification method.
The phase inversion emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to the organic continuous phase (O phase) to neutralize the aqueous medium. (W phase) is added to convert the resin from W / O to O / W (so-called phase inversion) to form a discontinuous phase and disperse the resin in an aqueous medium in the form of particles. It is.

The volume average particle size of the resin particles dispersed in the resin particle dispersion is preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, further 0.1 μm or more and 0.6 μm or less. preferable.
In addition, the volume average particle diameter of the resin particles is based on the particle size range (channel) divided by using the particle size distribution obtained by measurement with a laser diffraction particle size distribution measuring apparatus (for example, LA-700 manufactured by Horiba, Ltd.). The cumulative distribution is subtracted from the small particle diameter side with respect to the volume, and the particle diameter that becomes 50% cumulative with respect to all particles is measured as the volume average particle diameter D50v. The volume average particle size of particles in other dispersions is also measured in the same manner.

  As content of the resin particle contained in a resin particle dispersion liquid, 5 to 50 mass% is preferable, for example, and 10 to 45 mass% is more preferable.

  For example, a colorant particle dispersion and a release agent particle dispersion are also prepared in the same manner as the resin particle dispersion. In other words, regarding the volume average particle diameter of the particles in the resin particle dispersion, the dispersion medium, the dispersion method, and the content of the particles, the colorant particles dispersed in the colorant particle dispersion and the release agent particle dispersion The same applies to the release agent particles to be dispersed.

-Aggregated particle formation process-
Next, the colorant particle dispersion and the release agent particle dispersion are mixed together with the resin particle dispersion.
Then, in the mixed dispersion, resin particles, colorant particles, and release agent particles are hetero-aggregated to have resin particles, colorant particles, and release agent particles having a diameter close to the diameter of the target toner particles. Aggregated particles are formed.

Specifically, for example, the flocculant is added to the mixed dispersion, and the pH of the mixed dispersion is adjusted to acidic (for example, the pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. The resin particles are heated to a glass transition temperature (specifically, for example, the glass transition temperature of the resin particles −30 ° C. or more and the glass transition temperature −10 ° C. or less), and the particles dispersed in the mixed dispersion liquid are aggregated. , Forming aggregated particles.
In the agglomerated particle forming step, for example, the above-mentioned flocculant is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is acidic (for example, the pH is 2 or more and 5 or less) ), And after adding a dispersion stabilizer as necessary, the heating may be performed.

Examples of the flocculant include a surfactant having a polarity opposite to that of the surfactant used as the dispersant added to the mixed dispersion, an inorganic metal salt, and a divalent or higher-valent metal complex. In particular, when a metal complex is used as the flocculant, the amount of the surfactant used is reduced, and the charging characteristics are improved.
If necessary, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is preferably used.

Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic substances such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include metal salt polymers.
A water-soluble chelating agent may be used as the chelating agent. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid, iminodiacid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), and the like.
As addition amount of a chelating agent, 0.01 mass part or more and 5.0 mass part or less are preferable with respect to 100 mass parts of resin particles, for example, and 0.1 mass part or more and less than 3.0 mass parts are more preferable.

-Fusion / unification process-
Next, the aggregated particle dispersion in which the aggregated particles are dispersed is heated to, for example, a glass transition temperature or higher of the resin particles (for example, a temperature of 10 to 30 ° C. higher than the glass transition temperature of the resin particles). Are fused and united to form toner particles.

Through the above steps, toner particles are obtained.
In addition, after obtaining the aggregated particle dispersion liquid in which the aggregated particles are dispersed, the aggregated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles are dispersed are further mixed, and the resin particles are further added to the surface of the aggregated particles. A process of aggregating to adhere to form second aggregated particles, and heating the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and coalesce the second aggregated particles. The toner particles may be manufactured through a step of forming toner particles having a core / shell structure.

Here, after completion of the fusion / unification process, toner particles formed in the solution are dried through a known washing process, solid-liquid separation process, and drying process to obtain toner particles.
In the washing step, it is preferable to sufficiently carry out substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, etc. are preferably performed from the viewpoint of productivity. In addition, the drying process is not particularly limited, but from the viewpoint of productivity, freeze drying, airflow drying, fluidized drying, vibration fluidized drying, or the like is preferably performed.

Next, a case where a toner having toner particles containing a urea-modified polyester resin is manufactured will be described.
Toner particles containing a urea-modified polyester resin as a binder resin are preferably obtained by the following dissolution suspension method. Although a method for obtaining toner particles containing unmodified polyester resin and urea-modified polyester resin as the binder resin will be described, the toner particles may contain only urea-modified polyester resin as the binder resin.

-Oil phase liquid preparation process-
An oil phase liquid prepared by dissolving or dispersing a toner particle material containing an unmodified polyester resin, a polyester prepolymer having an isocyanate group, an amine compound, a colorant, and a release agent in an organic solvent is prepared (oil phase liquid preparation step). . In the oil phase liquid preparation step, the toner particle material is dissolved or dispersed in an organic solvent to obtain a mixed liquid of the toner material.

  The oil phase liquid is prepared by 1) a method in which toner materials are collectively dissolved or dispersed in an organic solvent, and 2) after kneading the toner materials in advance and then dissolving or dispersing the kneaded material in an organic solvent. 3) A method of adjusting by dissolving an unmodified polyester resin, a polyester prepolymer having an isocyanate group, an amine compound in an organic solvent, and then dispersing a glittering pigment and a release agent in the organic solvent. 4) A method in which a colorant and a release agent are dispersed in an organic solvent, and then an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound are dissolved in the organic solvent, and 5) Toner particle materials (unmodified polyester resin, glitter pigment, and release agent) other than polyester prepolymers having isocyanate groups and amine compounds are organically soluble. 6) A method for preparing a polyester prepolymer having an isocyanate group and an amine compound in this organic solvent, and 6) toner particle material other than the polyester prepolymer having an isocyanate group or the amine compound (not yet prepared). Examples include a method in which a modified polyester resin, a bright pigment, and a release agent) are dissolved or dispersed in an organic solvent, and then the polyester prepolymer or amine compound having an isocyanate group is dissolved in the organic solvent. . The method for preparing the oil phase liquid is not limited to these.

  Examples of the organic solvent for the oil phase liquid include ester solvents such as methyl acetate and ethyl acetate; ketone solvents such as methyl ethyl ketone and methyl isopropyl ketone; aliphatic hydrocarbon solvents such as hexane and cyclohexane; dichloromethane, chloroform, trichloroethylene, and the like Examples thereof include halogenated hydrocarbon solvents. These organic solvents are those that dissolve the binder resin, have a ratio of dissolving in water of about 0% by mass to 30% by mass, and preferably have a boiling point of 100 ° C. or less. Of these organic solvents, ethyl acetate is preferred.

-Suspension preparation process-
Next, the obtained oil phase liquid is dispersed in an aqueous phase liquid to prepare a suspension (suspension preparation step).
Then, along with the preparation of the suspension, the polyester prepolymer having an isocyanate group and the amine compound are reacted. This reaction produces a urea-modified polyester resin. This reaction is accompanied by at least one of a molecular chain crosslinking reaction and an extension reaction. In addition, you may perform reaction of the polyester prepolymer which has this isocyanate group, and an amine compound with the organic solvent removal process mentioned later.
Here, the reaction conditions are selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer and the amine compound. As an example, the reaction time is preferably 10 minutes to 40 hours, and more preferably 2 hours to 24 hours. The reaction temperature is preferably 0 ° C. or higher and 150 ° C. or lower, and preferably 40 ° C. or higher and 98 ° C. or lower. In addition, you may use a well-known catalyst (Dibutyltin laurate, a dioctyltin laurate, etc.) as needed for the production | generation of a urea modified polyester resin. That is, the catalyst may be added to the oil phase liquid or suspension.

  Examples of the aqueous phase liquid include an aqueous phase liquid in which a particle dispersant such as an organic particle dispersant and an inorganic particle dispersant is dispersed in an aqueous solvent. Examples of the aqueous phase liquid include an aqueous phase liquid in which the particle dispersant is dispersed in an aqueous solvent and the polymer dispersant is dissolved in the aqueous solvent. In addition, you may add well-known additives, such as surfactant, to an aqueous phase liquid.

  Examples of the aqueous solvent include water (for example, usually ion-exchanged water, distilled water, and pure water). An aqueous solvent is a solvent containing water and an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), and lower ketones (acetone, methyl ethyl ketone, etc.). There may be.

  Examples of the organic particle dispersant include hydrophilic organic particle dispersants. Examples of the organic particle dispersant include particles of poly (meth) acrylic acid alkyl ester resin (for example, polymethyl methacrylate resin), polystyrene resin, poly (styrene-acrylonitrile) resin, and the like. Examples of the organic particle dispersant include styrene acrylic resin particles.

  Examples of the inorganic particle dispersant include hydrophilic inorganic particle dispersants. Specific examples of the inorganic particle dispersant include particles of silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, clay, diatomaceous earth, bentonite, and the like, but calcium carbonate particles are preferable. An inorganic particle dispersing agent may be used individually by 1 type, and may use 2 or more types together.

The particle dispersant may be surface-treated with a polymer having a carboxyl group on the surface.
Examples of the polymer having a carboxyl group include a carboxyl group of an α, β-monoethylenically unsaturated carboxylic acid or an α, β-monoethylenically unsaturated carboxylic acid formed by an alkali metal, an alkaline earth metal, ammonium, an amine, or the like. And a copolymer of at least one selected from neutralized salts (alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc.) and α, β-monoethylenically unsaturated carboxylic acid esters. It is done. As the polymer having a carboxyl group, the carboxyl group of a copolymer of an α, β-monoethylenically unsaturated carboxylic acid and an α, β-monoethylenically unsaturated carboxylic acid ester is an alkali metal or an alkaline earth metal. And salts neutralized with ammonium, amine, etc. (alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc.). The said polymer which has a carboxyl group may be used individually by 1 type, and may use 2 or more types together.

  Typical α, β-monoethylenically unsaturated carboxylic acids include α, β-unsaturated monocarboxylic acids (acrylic acid, methacrylic acid, crotonic acid, etc.), α, β-unsaturated dicarboxylic acids (maleic acid). Acid, fumaric acid, itaconic acid, etc.). Representative examples of α, β-monoethylenically unsaturated carboxylic acid esters include alkyl esters of (meth) acrylic acid, (meth) acrylates having an alkoxy group, (meth) acrylates having a cyclohexyl group, Examples include (meth) acrylate having a hydroxy group, polyalkylene glycol mono (meth) acrylate, and the like.

  Examples of the polymer dispersant include hydrophilic polymer dispersants. Specifically, as the polymer dispersant, a polymer dispersant having a carboxyl group and having no lipophilic group (hydroxypropoxy group, methoxy group, etc.) (for example, water-soluble carboxymethyl cellulose, carboxyethyl cellulose, etc.) ).

-Solvent removal step-
Next, the organic solvent is removed from the obtained suspension to obtain a toner particle dispersion (solvent removal step). In this solvent removal step, the organic solvent contained in the droplets of the aqueous phase liquid dispersed in the suspension is removed to generate toner particles. The removal of the organic solvent from the suspension may be performed immediately after the suspension preparation step, or may be performed after 1 minute or more has elapsed after completion of the suspension preparation step.
In the solvent removal step, the organic solvent is preferably removed from the suspension by cooling or heating the obtained suspension in a range of 0 ° C. or more and 100 ° C. or less, for example.

Specific methods for removing the organic solvent include the following methods.
(1) A method of forcibly renewing the gas phase on the surface of the suspension by blowing an air stream on the suspension. In this case, gas may be blown into the suspension.
(2) A method of reducing the pressure. In this case, the gas phase on the surface of the suspension may be forcibly updated by filling with gas, or gas may be blown into the suspension.

Through the above steps, toner particles are obtained.
Here, after completion of the solvent removal step, toner particles formed in the toner particle dispersion are dried through a known washing step, solid-liquid separation step, and drying step to obtain toner particles.
In the washing step, it is preferable to sufficiently carry out substitution washing with ion-exchanged water from the viewpoint of chargeability.
The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, etc. are preferably performed from the viewpoint of productivity. Also, the drying process is not particularly limited, but from the viewpoint of productivity, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying, or the like is preferably performed.

  The toner according to the exemplary embodiment is manufactured, for example, by adding an external additive to the obtained dry toner particles and mixing them. Mixing may be performed by, for example, a V blender, a Henschel mixer, a Laedige mixer, or the like. Further, if necessary, coarse toner particles may be removed using a vibration sieving machine, a wind sieving machine, or the like.

<Electrostatic image developer>
The electrostatic charge image developer according to the exemplary embodiment is preferably a two-component developer mixed with the toner and the carrier according to the exemplary embodiment.

There is no restriction | limiting in particular as a carrier, A well-known carrier is mentioned. As a carrier, for example, a coated carrier in which the surface of a core made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and mixed in a matrix resin; a porous magnetic powder is impregnated with a resin Resin impregnated type carriers; and the like.
Note that the magnetic powder-dispersed carrier and the resin-impregnated carrier may be a carrier in which the constituent particles of the carrier are used as a core material and coated with a coating resin.

  Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite. Among these, ferrite is preferable.

Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.
Examples of the coating resin and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid ester. Examples thereof include a straight silicone resin comprising a copolymer, an organosiloxane bond, or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
The coating resin and matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating layer forming solution obtained by dissolving the coating resin and, if necessary, various additives in an appropriate solvent may be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include a dipping method in which the core material is immersed in the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the surface of the core material, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and the solvent is removed.

The surface roughness index Ra of the carrier in the present embodiment is preferably 0.2 μm or more and 1.5 μm or less, and preferably 0.4 μm or more, from the viewpoints of adhesion of the external additive to the carrier surface and removability. More preferably, it is 1.5 μm or less, and particularly preferably 0.4 μm or more and 0.8 μm or less.
In addition, the surface roughness index Sm of the carrier in the present embodiment is preferably 0.6 μm or more and 3.7 μm or less, more preferably 1.0 μm or more and 3.5 μm or less, from the viewpoint of chargeability. It is particularly preferable that the thickness is 2.0 μm or more and 3.0 μm or less.

In the present embodiment, the surface roughness indices Ra and Sm of the carrier are measured by the following method.
The method for measuring Ra (arithmetic mean roughness) of the carrier surface is to convert the surface at a magnification of 1,000 times using 2,000 carriers and an ultra-deep color 3D shape measuring microscope (VK9700, manufactured by Keyence Corporation). The method is determined according to JIS B0601 (1994 edition). Specifically, Ra of the carrier surface is a roughness curve obtained from the three-dimensional shape of the carrier surface observed with the microscope, and the measured value of the roughness curve and the absolute value of the deviation to the average value are summed up, It is obtained by averaging. The reference length for determining Ra on the carrier surface is 10 μm, and the cutoff value is 0.08 mm.
The carrier surface Sm (average irregularity spacing) is measured using 2,000 carriers and FE-SEM (S4100, manufactured by Hitachi High-Technologies Corporation), and the surface is converted at a magnification of 3,500 times. The method is determined according to JIS B0601 (1994 edition). Specifically, the Sm of the carrier surface is obtained by obtaining a roughness curve from the three-dimensional shape of the carrier surface observed with the microscope, and the interval of one cycle of the valley and the valley obtained from the intersection where the roughness curve intersects the average line. It is obtained from the average value. The reference length for determining Sm on the carrier surface is 10 μm, and the cutoff value is 0.08 mm.

  A method for manufacturing the carrier satisfying Ra and Sm is not particularly limited, but for example, it can be manufactured as follows.

  The surface roughness of the carrier (surface irregularity average spacing Sm and surface arithmetic surface roughness Ra) is adjusted to some extent by the temperature and oxygen concentration at the time of firing during the preparation of the ferrite particles. It is to change to a structure with magnetization.

Therefore, the magnetic particles constituting the carrier used in the present embodiment can be suitably manufactured by the following combinations (A) to (E).
(A) Temporary baking is performed before baking.
(B) The mixture is further pulverized and granulated from a slurry whose pulverized particle size is adjusted.
(C) SiO ₂ , SrCO ₃ or the like is used as a surface property adjusting agent.
(D) Adjusting the temperature and oxygen concentration during firing (E) Applying temperature while flowing the magnetic particles obtained by firing.

After preliminary firing before firing, the particle size is controlled by pulverization. Granulate into a pulverized product having the desired particle size and determine the volume average particle size. The size of the grain boundary, which is the basis of the magnetic particles, is controlled by the pulverized particle size after the preliminary firing. Further, the surface irregularities may be finely adjusted by using SiO ₂ , SrCO ₃ or the like as an additive. When SiO ₂ is added, the grain boundary area can be increased and the Sm can be adjusted. SrCO ₃ has the effect of increasing Ra.

  Next, firing is performed, the temperature and oxygen concentration are adjusted, and magnetization is combined to form ferrite. If the firing temperature is high, Sm is large, and if the oxygen concentration is high, Ra tends to be large. In addition, the firing temperature and oxygen concentration strongly affect the resistance and magnetization. The higher the temperature and the lower the oxygen concentration, the higher the magnetization and the lower the resistance.

  After firing is completed and ferritization is performed, the internal voids are reduced at a temperature at which no ferritization reaction occurs. Thereby, the target magnetic particle is obtained.

  The number average particle diameter of the carrier in this embodiment is preferably 15 μm or more and 70 μm or less, more preferably 20 μm or more and 60 μm or less, further preferably 22 μm or more and 50 μm or less, and particularly preferably 24 μm or more and 40 μm or less from the viewpoint of image density uniformity. .

A method for measuring the number average particle diameter of the carrier in this embodiment will be described below.
A Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) is used as a measuring device, and ISOTON-II (manufactured by Beckman Coulter, Inc.) is used as an electrolyte. First, a surfactant, preferably an alkylbenzenesulfone, is used as a dispersant. A sample to be measured is added in an amount of 0.5 mg to 50 mg in 2 ml of a 5% by weight aqueous solution of sodium acid, and added to 100 ml to 150 ml of the electrolyte. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size is 2.0 μm or more and 60 μm or less using the Coulter Multisizer II with an aperture having an aperture diameter of 100 μm. The particle size distribution of the particles in the range is measured. The number of particles to be measured is 50,000.
In the measured particle size distribution, a cumulative distribution is drawn from the small particle size side with respect to the divided particle size range (channel), and the particle size at which 50% is accumulated is defined as the number average particle size (D50v).

  The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

<Image Forming Apparatus / Image Forming Method>
The image forming apparatus / image forming method according to the present embodiment will be described.
The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and an electrostatic charge. Development means for containing an image developer and developing the electrostatic image formed on the surface of the image carrier as a toner image with the electrostatic image developer, and the toner image formed on the surface of the image carrier as a recording medium Transfer means for transferring to the surface of the recording medium, and fixing means for fixing the toner image transferred to the surface of the recording medium. The electrostatic charge image developer according to this embodiment is applied as the electrostatic charge image developer.

  In the image forming apparatus according to this embodiment, a charging process for charging the surface of the image carrier, an electrostatic charge image forming process for forming an electrostatic image on the surface of the charged image carrier, and an electrostatic charge according to this embodiment. A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with an image developer; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of the recording medium; An image forming method (an image forming method according to the present embodiment) including a fixing step of fixing the toner image transferred onto the surface of the recording medium is performed.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers a toner image formed on the surface of an image carrier to a recording medium; the toner image formed on the surface of the image carrier is transferred to an intermediate transfer member An intermediate transfer type apparatus that primarily transfers the toner image transferred to the surface of the intermediate transfer body and then secondary transfer the toner image to the surface of the recording medium; after the toner image is transferred, the surface of the image carrier before charging is cleaned. An apparatus provided with a cleaning unit; a known image forming apparatus such as an apparatus provided with a charge removing unit that discharges the surface of an image holding member by irradiating a discharge light after charging a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer means includes, for example, an intermediate transfer body on which a toner image is transferred to the surface, and a primary transfer that primarily transfers the toner image formed on the surface of the image holding body to the surface of the intermediate transfer body. And a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto the surface of the recording medium.

  In the image forming apparatus according to the present embodiment, for example, the part including the developing unit may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge including a developing unit containing the electrostatic charge image developer according to the present embodiment is preferably used.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 and a support roll 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other in the left to right direction in the drawing. The vehicle travels in the direction toward the unit 10K. The support roll 24 is applied with a force in a direction away from the drive roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the support roll 24. An intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K has yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The toner including the four color toners is supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. It should be noted that reference numerals with magenta (M), cyan (C), and black (K) are attached to the same parts as those of the first unit 10Y instead of yellow (Y). Description of the units 10M, 10C, and 10K will be omitted.

The first unit 10Y includes a photoreceptor 1Y that functions as an image holding member. Around the photoreceptor 1Y, a charging roll (an example of a charging unit) 2Y that charges the surface of the photoreceptor 1Y to a predetermined potential, and the charged surface is exposed by a laser beam 3Y based on the color-separated image signal. Then, an exposure device (an example of an electrostatic image forming unit) 3 that forms an electrostatic image, and a developing device (an example of a developing unit) 4Y that develops the electrostatic image by supplying toner charged to the electrostatic image, developed A primary transfer roll 5Y (an example of a primary transfer unit) that transfers a toner image onto the intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning unit) 6Y that removes toner remaining on the surface of the photoconductor 1Y after the primary transfer. Are arranged in order.
The primary transfer roll 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described.
First, prior to operation, the surface of the photoreceptor 1Y is charged to a potential of −600V to −800V by the charging roll 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive (for example, volume resistivity at 20 ° C .: 1 × 10 −6 Ωcm or less) substrate. This photosensitive layer usually has a high resistance (general resin resistance), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image having a yellow image pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoreceptor 1Y is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) as a toner image by the developing device 4Y.

  In the developing device 4Y, for example, an electrostatic charge image developer containing at least yellow toner and a carrier is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, has a charge of the same polarity (negative polarity) as the charged electric charge on the photoreceptor 1Y, and has a developer roll (of the developer holder). Example) is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoreceptor 1Y toward the primary transfer roll 5Y is applied to the toner image, so that the photoreceptor is exposed. The toner image on 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a (+) polarity opposite to the polarity (−) of the toner, and is controlled to +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the photoreceptor cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled in accordance with the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner. The

  The intermediate transfer belt 20 on which the four color toner images are transferred in multiple ways through the first to fourth units is disposed on the image transfer surface side of the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roll (an example of a secondary transfer unit) 26 is formed to a secondary transfer portion configured. On the other hand, a recording paper (an example of a recording medium) P is fed at a predetermined timing into a gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact via a supply mechanism, and the secondary transfer bias is supplied to the support roll. 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, so The toner image is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

  Thereafter, the recording paper P is fed into the pressure contact portions (nip portions) of a pair of fixing rolls in a fixing device (an example of a fixing unit) 28, and the toner image is fixed on the recording paper P to form a fixed image.

Examples of the recording paper P to which the toner image is transferred include plain paper used in electrophotographic copying machines, printers, and the like. In addition to the recording paper P, the recording medium may be an OHP sheet.
In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is also preferably smooth. For example, coated paper whose surface of plain paper is coated with resin, art paper for printing, etc. are preferably used. Is done.

  The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.

<Process cartridge / toner cartridge>
The process cartridge according to this embodiment will be described.
The process cartridge according to the present embodiment accommodates the electrostatic charge image developer according to the present embodiment, and develops the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer. And a process cartridge that can be attached to and detached from the image forming apparatus.

  Note that the process cartridge according to the present embodiment is not limited to the above-described configuration, and other means such as a developing device and other units such as an image carrier, a charging unit, an electrostatic charge image forming unit, and a transfer unit, if necessary. And at least one selected from the above.

  Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited to this. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

FIG. 2 is a schematic configuration diagram showing a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 2 is provided around the photoconductor 107 and the photoconductor 107 by, for example, a housing 117 provided with an attachment rail 116 and an opening 118 for exposure. A charging roller 108 (an example of a charging unit), a developing device 111 (an example of a developing unit), and a photoconductor cleaning device 113 (an example of a cleaning unit) are integrally combined and held to form a cartridge. Yes.
In FIG. 2, 109 is an exposure device (an example of an electrostatic charge image forming unit), 112 is a transfer device (an example of a transfer unit), 115 is a fixing device (an example of a fixing unit), and 300 is a recording paper (a recording medium). An example).

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present exemplary embodiment is a toner cartridge that accommodates the toner according to the present exemplary embodiment and is detachable from the image forming apparatus. The toner cartridge contains toner for replenishment to be supplied to the developing means provided in the image forming apparatus.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are each developing devices (colors). And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to the following examples. Unless otherwise specified, “parts” and “%” represent “parts by mass” and “mass%”.

[Preparation of resin particle dispersion (A)]
・ Terephthalic acid: 30 mol part ・ Fumaric acid: 70 mol part ・ Bisphenol A ethylene oxide adduct: 12 mol part ・ Bisphenol A propylene oxide adduct: 88 mol part A stirrer, nitrogen introduction tube, temperature sensor and rectifying tower The flask was equipped with the above material, and the temperature was raised to 210 ° C. over 1 hour, and 1 part of titanium tetraethoxide was added to 100 parts of the material. The temperature was raised to 230 ° C. over 0.5 hours while distilling off the produced water, and the dehydration condensation reaction was continued at that temperature for 1 hour, and then the reaction product was cooled. Thus, a polyester resin (A) was synthesized.
In a container equipped with temperature control means and nitrogen replacement means, 40 parts of ethyl acetate and 25 parts of 2-butanol are added to make a mixed solvent, and then 100 parts of polyester resin (A) is gradually added and dissolved therein. A 10% by mass aqueous ammonia solution (corresponding to 3 times the molar ratio with respect to the acid value of the resin) was added and stirred for 30 minutes.
Next, the inside of the container was replaced with dry nitrogen, the temperature was maintained at 40 ° C., and 400 parts of ion-exchanged water was added dropwise at a rate of 2 parts / minute while stirring the mixed solution to carry out emulsification. After completion of the dropwise addition, the emulsion is returned to room temperature (20 ° C. to 25 ° C.), and stirred for 48 hours with dry nitrogen to reduce ethyl acetate and 2-butanol to 1,000 ppm or less, and ion-exchanged water. Was added to adjust the solid content to 20% by mass to obtain a resin particle dispersion (A) having a volume average particle size of 190 nm.

[Preparation of resin particle dispersion (B)]
-Dodecanedioic acid (1,10-decanedicarboxylic acid): 50 mole parts-1,9-nonanediol: 50 mole parts The above monomer components were placed in a reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas inlet tube. The reactor was replaced with dry nitrogen gas, and 0.25 parts of titanium tetrabutoxide (reagent) was added to 100 parts of the monomer component. After stirring and reacting at 170 ° C. for 3 hours under a nitrogen gas stream, the temperature was further raised to 220 ° C. over 1 hour, the pressure inside the reaction vessel was reduced to 3 kPa, and stirring reaction was performed for 13 hours under reduced pressure. Resin (B) was obtained.
In a reactor equipped with a condenser, a thermometer, a water dropping device and an anchor blade (Tokyo Rika Kikai Co., Ltd .: BJ-30N), 300 parts of polyester resin (B), 160 parts of methyl ethyl ketone (solvent), 100 parts of isopropyl alcohol (solvent) was added, and the resin was dissolved while stirring and mixing at 100 rpm while maintaining the temperature at 70 ° C. in a water circulating thermostat (dissolution preparation step).
Thereafter, the stirring rotation speed was set to 150 rpm, the water circulating thermostat was set to 66 ° C., 17 parts of 10% ammonia water (reagent) was added over 10 minutes, and then 7 parts of ion-exchanged water kept at 66 ° C. A total of 900 parts was dropped at a rate of / min to cause phase inversion to obtain an emulsion.
Immediately, 800 parts of the obtained emulsified liquid and 700 parts of ion-exchanged water were placed in an eggplant flask, and set in an evaporator (Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. While rotating the eggplant flask, the mixture was heated in a hot water bath at 60 ° C., and the solvent was removed by reducing the pressure to 7 kPa while paying attention to bumping. When the solvent recovery amount reached 1,100 parts, the pressure was returned to normal pressure, and the eggplant flask was cooled with water to obtain a dispersion. There was no solvent odor in the obtained dispersion. The volume average particle diameter D50v of the resin particles in this dispersion was 130 nm. Then, ion-exchange water was added and it prepared so that solid content concentration might be 20 mass%, and this was made into the resin particle dispersion liquid (B).

[Preparation of release agent particle dispersion (1)]
Fischer-Tropsch wax (Nihon Seiwa Co., Ltd. FNP-0090, melting temperature 90 ° C.): 100 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part Ion-exchanged water : 400 parts The above materials were mixed, heated to 100 ° C., dispersed using a homogenizer (Ultra Tarax T50, manufactured by IKA), then dispersed with a Menton Gorin high-pressure homogenizer (manufactured by Gorin), and the volume average particle diameter A release agent particle dispersion (1) (solid content 20% by mass) in which 203 nm release agent particles were dispersed was obtained.

[Preparation of Colorant Particle Dispersion (1)]
・ Regal 330 (manufactured by Cabot Corporation): 50 parts ・ Ionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 5 parts ・ Ion-exchanged water: 200 parts The product was treated at 240 MPa for 10 minutes using a Sugino machine to prepare a colorant particle dispersion (solid content concentration: 20% by mass).

[Preparation of Toner Particle 1]
Resin particle dispersion (A): 400 parts by weight Resin particle dispersion (B): 300 parts by weight Release agent particle dispersion (1): 50 parts by weight Colorant particle dispersion (1): 50 parts by weight Part The above components were placed in a cylindrical stainless steel container, and dispersed and mixed for 10 minutes while applying a shearing force at 4,000 rpm with a homogenizer (manufactured by IKA, Ultra Tarrax T50). Subsequently, 1.75 parts of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant was gradually added dropwise, and the homogenizer was rotated at 5,000 rpm and dispersed for 15 minutes to prepare a raw material dispersion.
Thereafter, the raw material dispersion is transferred to a polymerization kettle equipped with a four-paddle stirring blade and a thermometer, and the mixture is started to be heated with a mantle heater at a rotation speed of 700 rpm and agglomerated at 45 ° C. Promoted particle growth. At this time, the pH of the dispersion was controlled in the range of 2.2 to 3.5 using 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The agglomerated particles were formed by maintaining the above pH range for about 2 hours.
Next, 200 parts of resin particle dispersion (A) was additionally added, and the resin particles of the binder resin were adhered to the surface of the aggregated particles. The temperature was further raised to 47 ° C., and aggregated particles were prepared while confirming the size and form of the particles with an optical microscope and Multisizer II. Thereafter, 2.25 parts of a chelating agent (HIDS, manufactured by Nippon Shokubai Co., Ltd.) was added, and then the pH was adjusted to 7.8 using a 5% aqueous sodium hydroxide solution and held for 15 minutes. Thereafter, the pH was raised to 8.0 in order to fuse the aggregated particles, and then the temperature was raised to 85 ° C. After confirming that the aggregated particles were fused with an optical microscope, the mixture was cooled at a temperature decrease rate of 1.0 ° C./min. Thereafter, the mixture was sieved with a 20 μm mesh, washed repeatedly with water, and then dried with a vacuum dryer to obtain toner particles 1. The obtained toner particles 1 had a volume average particle diameter of 5.6 μm and an average circularity of 0.965.

[Preparation of small-diameter toner particles 1]
Resin particle dispersion (A): 600 parts by weight Resin particle dispersion (B): 300 parts by weight Release agent particle dispersion (1): 50 parts by weight Colorant particle dispersion (1): 50 parts by weight Part The above components were placed in a cylindrical stainless steel container, and dispersed and mixed for 10 minutes while applying a shearing force at 4,000 rpm with a homogenizer (manufactured by IKA, Ultra Tarrax T50). Next, 0.3 part of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant was gradually added dropwise, and the homogenizer was rotated at 5,000 rpm for 15 minutes and mixed to obtain a raw material dispersion.
Thereafter, the raw material dispersion is transferred to a polymerization kettle equipped with a four-paddle stirring blade and a thermometer, and the mixture is started to be heated with a mantle heater at a rotation speed of 700 rpm and agglomerated at 45 ° C. Promoted particle growth. At this time, the pH of the dispersion was controlled in the range of 3.8 to 5.0 using 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The agglomerated particles were formed by maintaining the above pH range for about 30 minutes.
Thereafter, 2.25 parts of a chelating agent (HIDS, manufactured by Nippon Shokubai Co., Ltd.) was added, and then the pH was adjusted to 7.8 using a 5% aqueous sodium hydroxide solution and held for 15 minutes. Thereafter, the pH was raised to 8.0 in order to fuse the aggregated particles, and then the temperature was raised to 85 ° C. After confirming that the aggregated particles were fused with an optical microscope, the mixture was cooled at a temperature decrease rate of 1.0 ° C./min. Thereafter, the mixture was sieved with a 20 μm mesh, washed repeatedly with water, and then dried with a vacuum dryer to obtain small-diameter toner particles 1. The obtained small-diameter toner particles 1 had a volume average particle diameter of 1.6 μm and an average circularity of 0.989.

[Preparation of Toner 1]
95 parts of toner particles 1, 5 parts of small diameter toner particles 1 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed at a peripheral speed of 30 m / s for 2 minutes using a Henschel mixer. Thus, toner 1 was obtained.

[Production of Carrier a]
<Preparation of ferrite core material 1>
100 parts by mass of Fe ₂ O ₃ , 20.7 parts by mass of MnO ₂ and 0.50 parts by mass of SrCO ₃ were mixed, pulverized and mixed for 10 hours in a wet ball mill, dried, and then dried at 900 ° C. using a rotary kiln. Pre-baking was performed for 4 hours. Water is added to the calcined product thus obtained, and an appropriate amount of a dispersant and a binder are added to the slurry obtained by pulverizing with a wet ball mill for 9 hours, and then granulated and dried with a spray dryer to obtain a granulated product. It was. The obtained granulated material was fired at 1,000 ° C. for 6 hours in an electric furnace. A ferrite core material 1 having a number average particle diameter of 32 μm according to the above measuring method was prepared through a crushing step and a classification step.

<Preparation of carrier a>
Ferrite core material 1: 100 parts Methyl methacrylate / dimethylamino methacrylate copolymer (copolymerization ratio 95: 5, mol ratio): 3 parts Carbon black (VXC72, manufactured by Cabot Corporation): 0.3 parts Toluene: 14 parts Among the components shown in the carrier composition, each component except for the ferrite core material 1 and glass beads (φ1 mm, the same amount as toluene) are stirred for 1,200 ppm / 30 min using a sand mill manufactured by Kansai Paint Co., Ltd. Resin coating layer forming solution 1 was obtained. Furthermore, this resin coating layer forming solution 1 and the ferrite core material 1 were placed in a vacuum degassing kneader to distill off toluene, thereby forming a resin-coated carrier. Subsequently, carrier a was obtained by removing fine powder / coarse powder with an elbow jet. As a result of image analysis described later, the number average particle diameter was 34 μm, Ra was 0.6 μm, and Sm was 2.5 μm.

[Preparation of Developer 1]
To 100 parts of carrier a, 7 parts of toner 1 was mixed, stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having an opening of 250 μm to obtain developer 1.

[Preparation of toner particles 2 to 7]
In the production of the toner particles 1, toner particles 2 to 7 having different volume average particle diameters and average circularity were obtained by changing the time for maintaining aggregation at 45 ° C. and the time for fusing at 85 ° C. The volume average particle diameter and average circularity of each toner particle were as follows.
Toner particles 2 had a volume average particle diameter of 6.8 μm and an average circularity of 0.960.
Toner particles 3 had a volume average particle diameter of 5.2 μm and an average circularity of 0.962.
The toner particles 4 had a volume average particle diameter of 7.5 μm and an average circularity of 0.962.
The volume average particle diameter of the toner particles 5 is 4.8 μm, and the average circularity is 0.957.
The toner particles 6 have a volume average particle diameter of 5.6 μm and an average circularity of 0.930.
Toner particles 7 had a volume average particle diameter of 5.6 μm and an average circularity of 0.985.

[Preparation of small diameter toner particles 2 to 7]
Small toner particles 2 to 7 having different volume average particle diameters and average circularity were obtained by changing the time for maintaining aggregation at 45 ° C. and the time for fusing at 85 ° C. in the production of small diameter toner particles 1. . The volume average particle diameter and the average circularity of each small diameter toner particle were as follows.
The volume average particle diameter of the small-diameter toner particles 2 was 2.9 μm, and the average circularity was 0.983.
The volume average particle diameter of the small diameter toner particles 3 was 2.3 μm, and the average circularity was 0.988.
The small-diameter toner particles 4 had a volume average particle diameter of 1.2 μm and an average circularity of 0.990.
The small-diameter toner particles 5 had a volume average particle diameter of 2.0 μm and an average circularity of 0.988.
The small-diameter toner particles 6 had a volume average particle diameter of 1.6 μm and an average circularity of 0.938.
The volume average particle diameter of the small-diameter toner particles 7 is 1.6 μm, and the average circularity is 0.989.

<Preparation of ferrite core material 2>
A ferrite core material 2 having a number average particle size = 56 nm was obtained in the same manner except that the firing temperature and pulverization time were changed in the production of the ferrite 1.

[Production of Carrier b]
A carrier b was obtained in the same manner except that the ferrite core material 1 was changed to the ferrite core material 2 in the production of the carrier a. As a result of image analysis described later, the number average particle size was 57 μm, Ra was 0.9 μm, and Sm was 3.2 μm.

(Preparation of resin particle dispersion A)
-Oil layer-
Styrene (manufactured by Wako Pure Chemical Industries, Ltd.): 30 parts by mass n-butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.): 10 parts by mass β-carboxyethyl acrylate (manufactured by Rhodia Nikka Co., Ltd.): 1 .3 parts by mass Dodecanethiol (Wako Pure Chemical Industries, Ltd.): 0.4 parts by mass

-Water layer 1-
Ion-exchanged water: 17 parts by weight Anionic surfactant (Dowfax, manufactured by Dow Chemical Co.): 0.4 parts by weight

-Water layer 2-
Ion-exchanged water: 40 parts by weight Anionic surfactant (Dowfax, manufactured by Dow Chemical Co.): 0.05 parts by weight Ammonium peroxodisulfate (manufactured by Wako Pure Chemical Industries, Ltd.): 0.4 parts by weight

  The above oil layer component and water layer 1 component were placed in a flask and mixed with stirring to obtain a monomer emulsion dispersion. The components of the aqueous layer 2 were put into a reaction vessel, the inside of the vessel was sufficiently replaced with nitrogen, and the reaction system was heated to 75 ° C. with an oil bath while stirring. The above monomer emulsified dispersion was gradually dropped into the reaction vessel over 3 hours to carry out emulsion polymerization. After completion of the dropping, the polymerization was further continued at 75 ° C., and the polymerization was terminated after 3 hours.

  The obtained resin particles were 250 nm when the volume average particle diameter D50v of the resin particles was measured with a laser diffraction particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.). Moreover, it was 53 degreeC when the glass transition point of resin was measured with the temperature increase rate of 10 degree-C / min using the differential scanning calorimeter (DSC-50, Shimadzu Corporation make). Moreover, it was 13,000 when the number average molecular weight (polystyrene conversion) was measured using THF as a solvent using the molecular weight measuring device (HLC-8020, Tosoh Corporation make). As a result, a resin particle dispersion A having a volume average particle size of 250 nm, a solid content of 40% by mass, a glass transition point of 52 ° C., and a number average molecular weight Mn of 13,000 was obtained.

(Preparation of toner particles 8)
Resin particle dispersion A: 350 parts by weight Colorant particle dispersion: 50 parts by weight Release agent particle dispersion (1): 50 parts by weight Polyaluminum chloride: 0.4 parts by weight

  The above components were thoroughly mixed and dispersed in a stainless steel flask using an IKE Ultra Turrax, and then heated to 48 ° C. while stirring the flask in an oil bath for heating. After maintaining at 48 ° C. for 80 minutes, 100 parts by mass of the same resin particle dispersion A as above was gradually added thereto.

  Then, after adjusting the pH in the system to 6.0 using a sodium hydroxide aqueous solution having a concentration of 0.5 mol / L, the stainless steel flask is sealed, and the stirring shaft seal is magnetically sealed while continuing stirring. Heat to 97 ° C. and hold for 3 hours. After completion of the reaction, the temperature lowering rate was cooled at 1 ° C./min, filtered and thoroughly washed with ion-exchanged water, and then solid-liquid separation was performed by Nutsche suction filtration. This was further redispersed using 3,000 parts by mass of ion-exchanged water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This washing operation was further repeated 5 times. When the pH of the filtrate was 6.54 and the electric conductivity was 6.5 μS / cm, No. 2 was obtained by Nutsche suction filtration. Solid-liquid separation was performed using 5A filter paper. Next, vacuum drying was continued for 12 hours to obtain toner particles 8.

  The toner particles 8 have a volume average particle diameter of 5.6 μm and an average circularity of 0.965.

[Preparation of small-diameter toner particles 8]
The toner particles 8 were prepared in the same manner except that the amount of polyaluminum chloride was changed to 0.1 parts by mass and the holding time at 48 ° C. was changed to 5 minutes, and the volume average particle diameter was 1.6 μm. Small-diameter toner particles 8 having an average circularity of 0.989 were obtained.

(Preparation of unmodified polyester resin (1))
-Terephthalic acid: 1,243 parts-Bisphenol A ethylene oxide adduct: 1,830 parts-Bisphenol A propylene oxide adduct: 840 parts After the above components were heated and mixed at 180 ° C, 3 parts of dibutyltin oxide were added, and 220 Water was distilled off while heating at 0 ° C. to obtain a polyester resin. 1,500 parts of cyclohexanone was added to the obtained polyester to dissolve the polyester resin, 250 parts of acetic anhydride was added to this cyclohexanone solution, and the mixture was heated at 130 ° C. Furthermore, this solution was heated under reduced pressure to remove the solvent and unreacted acid to obtain an unmodified polyester resin (1). The unmodified polyester resin (1) obtained had a glass transition temperature of 60 ° C.

(Preparation of polyester prepolymer (1))
-Terephthalic acid: 1,243 parts-Bisphenol A ethylene oxide adduct: 1,830 parts-Bisphenol A propylene oxide adduct: 840 parts After the above components were heated and mixed at 180 ° C, 3 parts of dibutyltin oxide were added, and 220 Water was distilled off while heating at 0 ° C. to obtain a polyester prepolymer. 350 parts of the obtained polyester prepolymer, 50 parts of tolylene diisocyanate and 450 parts of ethyl acetate were put in a container, and this mixture was heated at 130 ° C. for 3 hours to obtain a polyester prepolymer having an isocyanate group (1) (hereinafter, “ An isocyanate-modified polyester prepolymer (1) ") was obtained.

(Preparation of ketimine compound (1))
A container was charged with 50 parts of methyl ethyl ketone and 150 parts of hexamethylenediamine, and stirred at 60 ° C. to obtain a ketimine compound (1).

[Preparation of Colorant Particle Dispersion (2)]
・ Regal 330 (manufactured by DIC Cabot Corporation): 10 parts ・ Ethyl acetate: 90 parts In the state where the above components are cooled to 10 ° C., they are wet pulverized by a microbead type disperser (DCP mill), and colorant particle dispersion liquid (2) was obtained.

(Preparation of release agent particle dispersion (2))
Fischer-Tropsch wax (Nippon Seiwa Co., Ltd. FNP-0090, melting temperature 90 ° C.): 30 parts Ethyl acetate: 270 parts A microbead disperser (DCP mill) with the above components cooled to 10 ° C. To obtain a release agent particle dispersion (2).

(Preparation of oil phase liquid (1))
Unmodified polyester resin (1): 136 parts Ethyl acetate: 56 parts After stirring and mixing the above components, 75 parts of the release agent particle dispersion (2) and 75 parts of the colorant particle dispersion (2) are added to the resulting mixture. Part was added and stirred to obtain an oil phase liquid (1).

(Preparation of styrene acrylic resin particle dispersion (1))
-Styrene: 370 parts-n-Butyl acrylate: 30 parts-Acrylic acid: 4 parts-Dodecanethiol: 24 parts-Carbon tetrabromide: 4 parts The above components are mixed and dissolved into a nonionic surfactant. (Sanyo Kasei Kogyo Co., Ltd .: Nonipol 400) 6 parts and anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts in ion exchange water 560 parts dissolved in an aqueous solution in a flask. After the dispersion and emulsification, while mixing for 10 minutes, an aqueous solution in which 4 parts of ammonium persulfate was dissolved in 50 parts of ion-exchanged water was added thereto, and after replacing with nitrogen, the contents were 70 with stirring in the flask. The mixture was heated in an oil bath until it reached 0 ° C., and emulsion polymerization was continued for 5 hours. Thus, a styrene acrylic resin particle dispersion liquid (1) (resin particle concentration: 40% by mass) obtained by dispersing resin particles having an average particle diameter of 180 nm and a weight average molecular weight (Mw) of 15,500 was obtained. The glass transition temperature of the styrene acrylic resin particles was 59 ° C.

(Preparation of aqueous phase liquid (1))
-Styrene acrylic resin particle dispersion (1): 60 parts-2% aqueous solution of Serogen BS-H (Daiichi Kogyo Seiyaku Co., Ltd.): 200 parts-Ion exchanged water: 200 parts A phase liquid (1) was obtained.

-Production of toner particles 9-
-Oil phase liquid (1): 300 parts-Isocyanate-modified polyester prepolymer (1): 25 parts-Ketimine compound (1): 0.5 part The above ingredients are put in a container and homogenizer (Ultra Turrax T50, manufactured by IKA Corporation). ) To obtain an oil phase liquid (1P), 1,000 parts of the aqueous phase liquid (1) was added to the container, and the mixture was stirred with a homogenizer for 20 minutes. Next, this mixture is stirred with a propeller-type stirrer at room temperature (25 ° C.) and normal pressure (1 atm) for 48 hours to react the isocyanate-modified polyester prepolymer (1) with the ketimine compound (1), A urea-modified polyester resin was produced and the organic solvent was removed to form a granular material. Next, the granular material was washed with water, dried and classified to obtain toner particles 9.
The obtained toner particles 9 had a volume average particle diameter of 5.6 μm and an average circularity of 0.961.

[Preparation of small-diameter toner particles 9]
After the toner particles were obtained in the same manner as the preparation of the toner particles 9, the large diameter particles were removed with an elbow jet classifier to obtain small diameter toner particles 9 having a volume average particle diameter of 1.6 μm and an average circularity of 0.979. .

[Production of Toner 2]
93.5 parts of toner particles 1, 6.5 parts of small-diameter toner particles 2 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) at a peripheral speed of 30 m / s using a Henschel mixer Toner 2 was obtained by mixing for 2 minutes.

[Production of Toner 3]
94 parts of toner particles 1, 6 parts of small-diameter toner particles 3 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed for 2 minutes with a Henschel mixer at a peripheral speed of 30 m / s. Thus, Toner 3 was obtained.

[Preparation of Toner 4]
93.5 parts of toner particles 1, 6.5 parts of small-diameter toner particles 4 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) at a peripheral speed of 30 m / s using a Henschel mixer Toner 4 was obtained by mixing for 2 minutes.

[Preparation of Toner 5]
97.5 parts of toner particles 2, 2.5 parts of small-diameter toner particles 4 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) at a peripheral speed of 30 m / s using a Henschel mixer Toner 5 was obtained by mixing for 2 minutes.

[Production of Toner 6]
93 parts of toner particles 3, 7 parts of small-diameter toner particles 5 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed for 2 minutes at a peripheral speed of 30 m / s using a Henschel mixer. Thus, toner 6 was obtained.

[Preparation of Toner 7]
95 parts of toner particles 4, 5 parts of small-diameter toner particles 4 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed for 2 minutes with a Henschel mixer at a peripheral speed of 30 m / s. Thus, Toner 7 was obtained.

[Preparation of Toner 8]
98.5 parts of toner particles 4, 1.5 parts of small-diameter toner particles 4 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) at a peripheral speed of 30 m / s using a Henschel mixer Toner 8 was obtained by mixing for 2 minutes.

[Preparation of Toner 9]
81 parts of toner particles 5, 19 parts of small-diameter toner particles 5 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed for 2 minutes with a Henschel mixer at a peripheral speed of 30 m / s. Thus, toner 9 was obtained.

[Production of Toner 10]
95 parts of toner particles 6, 5 parts of small-diameter toner particles 6 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed for 2 minutes at a peripheral speed of 30 m / s using a Henschel mixer. Thus, toner 10 was obtained.

[Preparation of Toner 11]
95 parts of toner particles 7, 5 parts of small-diameter toner particles 7 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed for 2 minutes with a Henschel mixer at a peripheral speed of 30 m / s. Thus, toner 11 was obtained.

[Preparation of Toner 12]
98.2 parts of toner particles 3, 1.8 parts of small-diameter toner particles 5 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) at a peripheral speed of 30 m / s using a Henschel mixer The toner 12 was obtained by mixing for 2 minutes.

[Preparation of Toner 13]
89.5 parts of toner particles 1, 10.5 parts of small-diameter toner particles 1 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) at a peripheral speed of 30 m / s using a Henschel mixer The toner 13 was obtained by mixing for 2 minutes.

[Preparation of Toner 14]
99.5 parts of toner particles 2, 0.5 parts of small-diameter toner particles 4 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) at a peripheral speed of 30 m / s using a Henschel mixer Toner 14 was obtained by mixing for 2 minutes.

[Preparation of Toner 15]
76 parts of toner particles 5, 24 parts of small-diameter toner particles 5 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed at a peripheral speed of 30 m / s for 2 minutes using a Henschel mixer. Thus, toner 15 was obtained.

[Preparation of Toner 16]
95 parts of toner particles 8, 5 parts of small-diameter toner particles 8 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed for 2 minutes with a Henschel mixer at a peripheral speed of 30 m / s. Thus, toner 16 was obtained.

[Preparation of Toner 17]
95 parts of toner particles 9, 5 parts of small-diameter toner particles 9 and 1.5 parts of fumed silica (manufactured by Nippon Aerosil Co., Ltd., R972) are mixed for 2 minutes with a Henschel mixer at a peripheral speed of 30 m / s. Thus, toner 17 was obtained.

[Production of Developers 2 to 18]
Developers 2 to 18 were produced in the same manner as in the production of developer 1 using the toner and carrier described in Table 1.

(Measurement method of number particle size distribution, volume particle size distribution, volume average particle size and average circularity of toner particles)
It measured by the measuring method mentioned above using the flow type particle image analyzer FPIA-3000 (made by Sysmex Corporation).

(Measurement of carrier surface roughness)
The sample was observed at 1,000 times using a laser microscope VK9700 (manufactured by Keyence Corporation). The carrier surface roughness Ra was calculated from image observation of 2,000 particles. The carrier surface roughness Sm was calculated by image analysis of 2,000 particles with an image of 3,500 times using FE-SEM (S4100, manufactured by Hitachi High-Technologies Corporation).

(Evaluation)
-Image density uniformity (image density uniformity of halftone images output after continuous output of images with high image density in part)-
The obtained developer was evaluated as follows using a DocuPrint P450d remodeling machine manufactured by Fuji Xerox Co., Ltd.
After printing 60 A4 images with 50% image density (right half is solid and left half is non-image part) in an environment of temperature 25 ° C and humidity 90% RH on the modified machine, the entire surface of image density 30% A halftone image was printed. The right side image density and the left side image density of the obtained halftone image were measured with an X-Rite spectrocolorimeter 962 (manufactured by X-Rite Co., Ltd.), and the difference was obtained.
A: The image density difference is 0.03 or less, and the image density uniformity is very good.
B: The image density difference is more than 0.03 and 0.05 or less, and the image density uniformity is good.
C: The image density difference is more than 0.05 and 0.10 or less, and the image density uniformity is an acceptable level.
D: The image density difference exceeds 0.10, and there is a problem in image density uniformity.

In the number particle size distribution of the toner particles, as schematically shown in FIG. 3, each of the toners of this example has one in each of the region of 0.5 μm to 2 μm and the region of 2 μm to 8 μm. It had a peak.
From the above results, it can be seen that the toner of this example has suppressed the decrease in image density uniformity as compared with the toner of the comparative example.

1Y, 1M, 1C, 1K photoconductor (an example of an image carrier)
2Y, 2M, 2C, 2K charging roll (an example of charging means)
3. Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K Laser beams 4Y, 4M, 4C, 4K Developing device (an example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (an example of primary transfer means)
6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt (an example of an intermediate transfer member)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photosensitive member (an example of an image holding member)
108 Charging roll (an example of charging means)
109 Exposure apparatus (an example of electrostatic charge image forming means)
111 Developing device (an example of developing means)
112 Transfer device (an example of transfer means)
113 photoconductor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Mounting rail 117 Housing 118 Opening 200 for exposure Process cartridge 300 Recording paper (an example of a recording medium)
P Recording paper (an example of a recording medium)

Claims (11)

A toner particle containing at least a binder resin and a colorant, and an external additive;
In the number particle size distribution of the toner particles, the ratio of toner particles having a particle size of 0.5 μm or more and 2 μm or less is 5% or more and 60% or less with respect to the whole toner particles, and the toner particles having a particle size of more than 2 μm and less than 50 μm. The ratio is 40% or more and 95% or less with respect to the whole toner particles,
In the volume particle size distribution of the toner particles, the ratio of toner particles having a particle diameter of 0.5 μm or more and 2 μm or less is 0.6% or more and 10% or less with respect to the whole toner particles, and the toner having a particle diameter of more than 2 μm and 50 μm or less. An electrostatic image developing toner having a particle ratio of 90% or more and 99.4% or less with respect to the whole toner particles.   2. The electrostatic image development according to claim 1, wherein the number particle size distribution of the toner particles has at least one peak in each of a region having a particle size of 0.5 μm to 2 μm and a region having a particle size of more than 2 μm and 8 μm or less. toner.   The electrostatic charge image developing toner according to claim 1, wherein the toner particles have a volume average particle diameter of 4 μm or more and 10 μm or less.   4. The toner for developing an electrostatic charge image according to claim 1, wherein the toner particles having a particle diameter of 0.5 μm or more and 2 μm or less have an average circularity of 0.940 or more and 0.995 or less.   The toner particles having a particle size of 0.5 μm or more and 2 μm or less have an average circularity of C1 and an average circularity of all toner particles of C2, and 0.005 ≦ C1−C2 ≦ 0.050. 5. The toner for developing an electrostatic charge image according to any one of 4 above.   An electrostatic charge image developer comprising a carrier and the electrostatic charge image developing toner according to any one of claims 1 to 5.   The electrostatic charge image developer according to claim 6, wherein the number average particle diameter of the carrier is 15 μm or more and 70 μm or less. Containing the toner for developing an electrostatic image according to any one of claims 1 to 5,
A toner cartridge to be attached to and detached from the image forming apparatus. A developing means for containing the electrostatic charge image developer according to claim 6 or 7 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic charge image developer according to claim 6 or 7 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
An image forming apparatus comprising: A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer according to claim 6 or 7,
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image transferred to the surface of the recording medium;
An image forming method comprising: