JP6798205B2 - Toner for static charge image development, static charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developing agent, 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 mold release agent, and a colorant, and an external additive externally added to the toner particles. Many toners containing the above are used.

Further, examples of the conventional toner include the toners described in Patent Documents 1 to 3.
In Patent Document 1, in the particle size distribution displayed by the number distribution, each particle size distribution portion of less than 6.35 μ and 6.35 μ or more has a peak, and the peak value of 6.35 μ or less is 6.35 μ or more. For static charge image development, which is smaller than the peak value and has a number distribution of 0.5 μ or less of 1% or less, 6.35 μ or less of 15% or less, and 20.2 μ or more of 0.5% or less. The toner is listed.
According to Patent Document 2, in a developer composed of a toner and a carrier, the toner is a toner containing colored particles containing at least a binder resin and a coloring material, and resin fine particles and inorganic fine particles, and the resin. The fine particles are melamine / formaldehyde reduced polymer resin fine particles having a volume average particle size of 0.01 to 1.0 μm, and the inorganic fine particles have a volume average particle size of 0.01 to 0.20 μm and a volume average particle size distribution. The standard deviation (σ) is 10 ≦ σ ≦ 30, and the carriers are composed of at least a mixture or copolymer of an alicyclic methacrylic acid ester or a chain methacrylic acid ester homopolymer on magnetic particles, and inorganic fine particles. Described is a developer characterized by being a negatively charged carrier coated with a resin layer made of.
Patent Document 3 describes a developing toner characterized in that the toner particle size distribution has two peaks above and below the toner average particle size of 8 μm.

Japanese Patent No. 2663006 Japanese Unexamined Patent Publication No. 9-006039 Japanese Unexamined Patent Publication No. 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 in the number particle size distribution of toner particles is less than 5% or 60% with respect to the entire 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 entire toner particles. Compared with the case, it is an object of the present invention to provide a toner for static charge image development that suppresses a decrease in image density uniformity of a halftone image output after continuously outputting an image having a part having a high image density portion.

The above problem is solved by the following means.

< 1 > is
In the number particle size distribution of the toner particles having at least a binder resin, toner particles containing a colorant, and an external additive, the ratio of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is the toner particles. The ratio of 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 entire toner particles, and in the volume 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 0.6% or more and 10% or less with respect to the entire toner particles, and the ratio of toner particles having a particle size of more than 2 μm and 50 μm or less is the entire toner particles. On the other hand, it is a toner for static charge image development of 90% or more and 99.4% or less.

< 2 > is
The static charge image development according to < 1 > , which has at least one peak in each of the region of 0.5 μm or more and 2 μm or less and the region of more than 2 μm and 8 μm or less in the number particle size distribution of the toner particles. It is a toner.

< 3 > is
The toner for static charge image development according to < 1 > or < 2 > , wherein the volume average particle diameter of the toner particles is 4 μm or more and 10 μm or less.

< 4 > is
The average circularity of the particle diameter of 0.5μm or more 2μm or less of the toner particles is the toner for electrostatic image development according to any one of is 0.940 or more 0.995 or less <1> to <3> ..

< 5 > is
When 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, 0.005 ≦ C1-C2 ≦ 0.050 < 1 > to < 4. > The toner for developing an electrostatic charge image according to any one of.

< 6 > is
A carrier, a <1> to <5> The electrostatic image developer containing a toner for electrostatic image development according to any one of.

< 7 > is
The electrostatic charge image developer according to < 6 > , wherein the number average particle diameter of the carriers is 15 μm or more and 70 μm or less.

< 8 > is
<1> to accommodate the toner according to any one of <5>, a toner cartridge that is detachably attached to the image forming apparatus.

< 9 > is
A developing means for accommodating the electrostatic charge image developing agent according to < 6 > or < 7 > and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided. A process cartridge that is attached to and detached from the image forming apparatus.

< 10 > is
The image holder, the charging means for charging the surface of the image holder, and the static charge image forming means for forming a static charge image on the surface of the charged image holder, according to < 6 > or < 7 > . A developing means containing a static charge image developer and developing the static charge image formed on the surface of the image holder as a toner image by the static charge image developer, and a developing means formed on the surface of the image holder. An image forming apparatus including a transfer means for transferring a toner image to the surface of a recording medium and a fixing means for fixing the toner image transferred to the surface of the recording medium.

< 11 > is
By a charging step of charging the surface of the image holder, a static charge image forming step of forming a static charge image on the surface of the charged image holder, and the static charge image developer according to < 6 > or < 7 >. A development step of developing an electrostatic charge image formed on the surface of the image holder as a toner image, a transfer step of transferring the toner image formed on the surface of the image holder to the surface of a recording medium, and the recording. This is an image forming method including a fixing step of fixing a toner image transferred to the surface of a medium.

According to < 1 > , in the number particle size distribution of toner particles, whether 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 more than 60% with respect to the entire 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 entire toner particles. Provided is a toner for static charge image development 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 a part thereof.
According to < 2 > , in the particle size distribution of the number of toner particles, an image having a high image density portion in a part was continuously output as compared with the case where there is one peak in the region of the particle size of 0.5 μm or more and 8 μm or less. Provided is a toner for static charge image development that further suppresses a decrease in image density uniformity of a halftone image output later.
According to < 3 > , the image density uniformity of the halftone image output after continuously outputting an image having a high image density portion in a part is lowered as compared with the case where the volume average particle size of the toner particles is less than 4 μm. A toner for developing an electrostatic charge image is provided.
According to < 4 > , 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 image having a high image density portion is continuously output and then output. Provided is a toner for static charge image development that further suppresses a decrease in image density uniformity of a halftone image.
According to < 5 >, when 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, compared with the case where C1-C2> 0.050. Provided is a toner for static charge image development that further suppresses a decrease in image density uniformity of a halftone image output after continuously outputting an image having a high image density portion in a part thereof.

According to the invention according to < 6 > or < 7 > , in the number particle size distribution of toner particles of toner, the ratio of 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 entire 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% with respect to the entire toner particles. Alternatively, a static charge image developer 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 a part as compared with a case where it exceeds 10% is provided.
According to < 8 > , < 9 > , < 10 > or < 11 > , in the number particle size distribution of toner particles, the ratio of toner particles having a particle size of 0.5 μm or more and 2 μm or less is relative to the entire toner particles. 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, which is less than 5% or more than 60%, is 0.6% with respect to the entire toner particles. Toner cartridges and process cartridges that suppress the decrease in image density uniformity of halftone images output after continuously outputting images with a high image density portion in part compared to the case where the amount is less than or exceeds 10%. , An image forming apparatus or an image forming method is provided.

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

The present embodiment will be described below.
The descriptions of "parts by mass" and "% by mass" are synonymous with "parts by weight" and "% by weight", respectively.

<Toner for static charge image development>
The toner for static charge image development according to the present embodiment (also simply referred to as “toner”) has at least toner particles containing a binder resin and a colorant, and an external additive, and the number of the toner particles. In the particle size distribution, the ratio of toner particles with 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 entire toner particles, and the ratio of toner particles with a particle size of more than 2 μm and 50 μm or less is the toner particles. It is 40% or more and 95% or less with respect to the whole, and 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 0.6% or more and 10% with respect to the whole toner particles. The ratio of 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 entire toner particles.

With the above configuration, the toner for static charge image development according to the present embodiment suppresses a decrease in image density uniformity of a halftone image output after continuously outputting an image having a high image density portion in a part thereof. The reason for this is not clear, but it is presumed to be due to the following reasons.

In the image formation of the electrophotographic method, an image having a high image density part (specifically, for example, the right half of the image is a solid image (image density 100%) and the left half is a blank sheet (image density). If a halftone image is output after continuously outputting an image) of 0%), the image density uniformity may decrease. This is because by continuously outputting an image having a high image density portion in a part, a large amount of toner is consumed in the high image density portion, the external additive moves from the toner to the carrier of the portion, and the carrier of the other portion. More external additive remains than. For this reason, the carrier's external additive adhesion state is biased, and when a halftone image is output, the developability of the toner changes between the high image density portion and the other portion, resulting in a difference in image density. Is generated, and the image density uniformity is lowered.
Further, in a high humidity environment (for example, 90% RH), the deterioration of image density uniformity is likely to occur. It is considered that the reason is that the adhesive force between the carrier and the toner is increased by the liquid cross-linking force, so that the influence of the non-electrostatic adhesive force on the adhesion of the external additive to the carrier is increased.

In the present embodiment, the high image density portion means a portion having an image density of 70% or more, and examples thereof include a portion having an image density of 100%, that is, a so-called solid image portion. Further, in the present embodiment, the halftone image means a halftone dot image portion having an image density of 20% to 50%.

In the toner for static charge image development according to the present embodiment, as described above, the ratio of toner particles having a particle size of 0.5 μm or more and 2 μm or less is defined in a specific range in the number particle size distribution and the volume particle size distribution. It is shown that the toner for static charge image development according to the embodiment has more toner particles having a particle size of 0.5 μm or more and 2 μm or less than the conventional toner.

A part of the external additive adhering to the toner particles moves to the carrier surface by contact with the carrier. The surface of the carrier has irregularities, and when the external additive adhering to the carrier moves to the recesses on the surface, it reattaches to the toner having a normal particle size, for example, a volume average particle size of 4 μm or more and 10 μm or less. Hateful.
On the other hand, when small-diameter toner particles of 2 μm or less are present, when the carrier and the small-diameter toner particles collide, the small-diameter toner particles follow the unevenness of the carrier surface, and the external additive and the small-diameter toner particles existing in the recesses of the carrier By reattaching the particles, the external additive existing in the recesses on the carrier surface is removed after the images having a high image density portion in a part are 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 an image having a high image density portion in a part ( Hereinafter, the decrease in (hereinafter, also simply referred to as “image density uniformity”) is suppressed.

Hereinafter, the details of the toner for static charge image development according to the present embodiment will be described.

In the present embodiment, the number particle size distribution and the volume particle size distribution of the toner particles shall be measured by the following methods.
In order to measure the characteristics of the static charge image developing toner with respect to the toner particles, the external additive is separated from the toner particles by pretreatment, if necessary.
First, put 30 ml of ion-exchanged water in a 100 ml beaker, add 2 drops of a surfactant (manufactured by Wako Pure Chemical Industries, Ltd .: Contaminon) as a dispersant, and put 20 mg of the toner to be measured in this liquid. Disperse for 3 minutes by ultrasonic dispersion to prepare a toner particle dispersion for measurement.
Using the obtained toner particle dispersion and the 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. In this device, a method of measuring particles dispersed in water etc. by a flow type image analysis method is adopted, and the sucked particle suspension is guided to a flat sheath flow cell, and a sample flow is formed by the sheath liquid. To. By irradiating the sample stream with strobe light, the passing particles are imaged as a still image by the CCD camera through the objective lens. The captured particle image is subjected to two-dimensional image processing, the equivalent circle diameter is calculated, and the number particle size distribution and the volume particle size distribution are measured.

In the static charge image developing toner according to the present embodiment, 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 of the entire 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.
Further, in the toner for static charge image development according to the present embodiment, in the number 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 40% or more and 95% or less with respect to the entire 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 static charge image development toner according to the present embodiment, 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 0.6% or more and 10% or less with respect to the entire 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 static charge image development according to the present embodiment, the ratio of the toner particles having a particle size of more than 2 μm and 50 μm or less in the volume particle size distribution of the toner particles is 90% or more and 99.4% with respect to the entire 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.

In the number particle size distribution of the toner particles, the toner for static charge image development according to the present embodiment has a particle size of 0.5 μm or more and 2 μm or less and a particle size of more than 2 μm and 8 μm or less from the viewpoint of image density uniformity. It is preferable that each has at least one peak, and it is more preferable that each has one peak in 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 size (D50v) of the toner particles in the toner for static charge image development according to the present embodiment is preferably 2 μm or more and 15 μm or less, more preferably 4 μm or more and 10 μm or less, and 4 μm or more from the viewpoint of image density uniformity. 8 μm or less is particularly preferable.
The various average particle sizes and various particle size distribution indexes 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 Co., Ltd.) as described above. Toner.
Draw a cumulative distribution of volume and number from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and set the cumulative particle size to 50% by volume average particle size D50v and cumulative number. It is defined as the average particle size D50p.

From the viewpoint of image density uniformity, the average circularity of the toner particles in the electrostatic charge image developing toner according to the present embodiment is preferably 0.88 or more and 1.00 or less, and 0.90 or more and 0.998 or less. It is more preferable that the amount is 0.940 or more and 0.995 or less.
Further, in the toner for static charge image development according to the present 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. When, 0.005 ≦ C1-C2 ≦ 0.050 is preferable.

The average circularity of the toner particles in this embodiment is measured by FPIA-3000 manufactured by Simex Co., Ltd., which was used for measuring various particle size distribution indexes. With regard to the circularity, the average circularity is obtained by performing image analysis on each of 50,000 or more images and performing statistical processing.
・ Formula: Circularity = Circle equivalent diameter Peripheral length / Peripheral length = [2 × (Aπ) ^1/2 ] / PM
In the above equation, A represents the projected area and PM represents the peripheral length.
The HPF mode (high resolution mode) was used for the measurement, and the dilution ratio was 1.0 times. In the data analysis, the circularity analysis range was set to 0.40 or more and 1.00 or less for the purpose of removing measurement noise.

The toner for static charge image development according to the present embodiment is composed of toner particles and an external additive.

(Toner particles)
The toner particles are composed of a binder resin, a colorant, and if necessary, a mold release agent and other additives.

-Bound resin-
Examples of the binder resin include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, 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 (eg, acrylonitrile, Methacylonitrile, 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, butadiene, etc.), etc. Examples thereof include a homopolymer of the above-mentioned monomer and a vinyl-based resin composed of a copolymer obtained by combining two or more kinds of these monomers.
Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or these. Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

As the binder resin, a polyester resin is suitable.
Examples of the polyester resin include known amorphous polyester resins. As the polyester resin, a crystalline polyester resin may be used in combination with the amorphous polyester resin. However, the crystalline polyester resin may be used in a range of 2% by mass or more and 40% by mass or less (preferably 2% by mass or more and 20% by mass or less) with respect to the total binder resin.

The "crystallinity" of the resin means that the resin has a clear endothermic peak rather than a stepwise endothermic change in differential scanning calorimetry (DSC). Specifically, the temperature rise rate is 10 (° C.). It means that the half width of the endothermic peak when measured at / min) is within 10 ° C.
On the other hand, "amorphous" of the resin means that the half width exceeds 10 ° C., shows a stepwise endothermic amount change, or does not show a clear endothermic peak.

-Amorphous polyester resin Examples of the amorphous polyester resin include a condensed polymer of a polyvalent carboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, 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 acid (eg cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), these anhydrides, or their lower grades (eg, 1 or more carbon atoms). (5 or less) Alkyl ester can be mentioned. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

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, etc.). Hydrogenated bisphenol A, etc.), aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.) can be mentioned. Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
The polyhydric alcohol may be used alone or in combination of two or more.

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 obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in JIS K 7121-1987 "Method for measuring transition temperature of plastics". It is obtained by the "external glass transition start temperature" of.

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.
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 by using Tosoh's GPC / HLC-8120GPC as a measuring device, using Tosoh's column / TSKgel SuperHM-M (15 cm), and using a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

Amorphous 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 inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the monomer. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. If there is a monomer with poor compatibility, it is advisable to condense the monomer with poor compatibility with the monomer and the acid or alcohol to be polycondensed in advance, and then polycondensate 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. As the crystalline polyester resin, a commercially available product may be used, or a synthetic resin may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic is preferable to a polymerizable monomer having an aromatic.

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-nonandicarboxylic acid, and 1,10-decandicarboxylic acid. Acids, 1,12-dodecanedicarboxylic acids, 1,14-tetradecandicarboxylic acids, 1,18-octadecanedicarboxylic acids, etc., aromatic dicarboxylic acids (eg, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Examples thereof include dibasic acids such as acids), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. 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.). Anhydrides or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof can be mentioned.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include an aliphatic diol (for example, a linear aliphatic diol having 7 or more and 20 or less carbon atoms in the main chain portion). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-. Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples thereof include octadecanediol and 1,14-eicosanedecanediol. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol and 1,10-decanediol are preferable.
As the polyhydric alcohol, a trihydric or higher alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
The polyhydric alcohol may be used alone or in combination of two or more.

Here, the polyhydric alcohol preferably has an aliphatic diol content of 80 mol% or more, 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 DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperature of plastics".

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 inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the monomer. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility, the monomer, and the acid or alcohol to be polycondensed are condensed in advance, and then weighted 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-mentioned unmodified polyester resins. The modified polyester resin is a polyester resin having a bonding group other than an ester bond, 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. Examples of the modified polyester resin include a polyester resin having 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 at the terminal, and a resin having a modified terminal 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 the urea-modified polyester resin as the binder resin, it becomes easy to suppress the occurrence of a decrease in image density of the image formed in the region that was the non-image portion in the previous image formation cycle. This is the chemistry of the crosslinked and chemical structure of the urea-modified polyester resin (specifically, the physical properties of the resin due to the cross-linking of the urea-modified polyester resin, and the affinity between the polar binding group and the polar fatty acid metal salt particles. (Characteristics) It is considered that the structure makes it easier to improve the adhesive force between the toner particles, the fatty acid metal salt particles, and the abrasive particles, and makes it easier to control the range of the free amount ratio of the fatty acid metal salt particles and the abrasive particles. Because. From this point of view, 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 reacting a polyester resin having an isocyanate group (polyester prepolymer) with an amine compound (at least one reaction of a cross-linking reaction and an extension reaction). The urea-modified polyester resin may contain a urethane bond as well as 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 polyester having active hydrogen with a polyhydric isocyanate compound. .. Examples of the group having active hydrogen contained 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 the polyhydric alcohol include compounds similar to the polyvalent carboxylic acid and the polyhydric alcohol described in the polyester resin.

Polyisocyanate compounds include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatics. Diisocyanate (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); aromatic aliphatic diisocyanate (α, α, α', α'-tetramethylxylylene diisocyanate, etc.); isocyanurates; Examples include those blocked with a blocking agent.
The polyisocyanate compound may be used alone or in combination of two or more.

The ratio of the polyisocyanate compound is preferably 1/1 or more and 5/1 or less, as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester prepolymer having a hydroxyl group. It is preferably 1.2 / 1 or more and 4/1 or less, and more preferably 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, it becomes easier to suppress the occurrence of a decrease in image density of the image formed in the region that was the non-image portion in the previous image formation cycle. When [NCO] / [OH] is set to 5 or less, the decrease in low temperature fixability is likely to be suppressed.

In the polyester prepolymer having an isocyanate group, the content of the component derived from the polyhydric isocyanate compound is preferably 0.5% by mass or more and 40% by mass or less, more preferably, with respect to the entire polyester prepolymer having an isocyanate group. It is 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 20% by mass or less. When the content of the component derived from polyisocyanate is 0.5% by mass or more and 40% by mass or less, the occurrence of decrease in image density of the image formed in the region that was the non-image part in the previous image formation cycle is further suppressed. It becomes easy to be done. When the content of the component derived from the polyvalent isocyanate is 40% by mass or less, the decrease in low temperature fixability is easily suppressed.

The number of isocyanate groups contained in one molecule of the polyester prepolymer having an isocyanate group is preferably 1 or more on average, more preferably 1.5 or more and 3 or less on average, and still more preferably 1.8 or more on average 2. .5 or less. When the number of isocyanate groups is set to 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 region in the previous image formation cycle decreases. It becomes easier to be suppressed.

Examples of the amine compound that reacts with the polyester prepolymer having an isocyanate group include diamines, trivalent or higher polyamines, amino alcohols, amino mercaptans, amino acids, 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.) ); Examples include aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.).
Examples of the triamine or higher polyamine include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of amino acids include aminopropionic acid and aminocaproic acid.
Examples of those that block these amino groups include amine compounds such as diamines, trivalent or higher polyamines, aminoalcohols, aminomercaptans, and amino acids, and ketimine compounds obtained from ketone compounds (acetones, methyl ethyl ketones, methyl isobutyl ketones, etc.). Examples include oxazoline compounds.
Of these amine compounds, ketimine compounds are preferred.
The amine compound may be used alone or in combination of two or more.

The urea-modified polyester resin is a polyester resin (polyester prepolymer) having an isocyanate group by a terminator that terminates at least one of the crosslinking reaction and the elongation reaction (hereinafter, also referred to as “crosslinking / elongation reaction terminator”). The resin may have an adjusted molecular weight after the reaction by adjusting the reaction with the amine compound (at least one of the cross-linking reaction and the extension reaction).
Examples of the cross-linking / extension reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.) and those that block them (ketimine compounds).

The ratio of the amine compound is preferably 1/2 or more as the 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. It is 1/1 or less, more preferably 1 / 1.5 or more and 1.5 / 1 or less, and further preferably 1 / 1.2 or more and 1.2 / 1 or less. When [NCO] / [NHx] is set to 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 non-image region in the previous image formation cycle decreases more. 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 10,000 or more and 500,000 or less, and more preferably 30,000 or more and 100,000 or less.

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

-Colorant-
Colorants include, for example, carbon black, chrome yellow, Hansa yellow, benzine yellow, slene yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, brilliant. Carmin 6B, Dupont Oil Red, Pyrazolon Red, Resole Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultra Marine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or aclysine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black Examples thereof include various dyes such as system, polymethine type, triphenylmethane type, diphenylmethane type and thiazole type.
One type of colorant may be used alone, or two or more types may be used in combination.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. In addition, a plurality of types 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 the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; 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.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K 7121-1987 "Method for measuring transition temperature of plastics". ..

The content of the release agent is, for example, preferably 1% by mass or more and 20% 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.

-Other additives-
Examples of other additives include well-known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

-Characteristics of toner particles, etc.-
The toner particles may be toner particles having a single layer structure, or are toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) that covers the core portion. You may.
Here, the toner particles having a core-shell structure include, for example, a core portion composed of a binder resin and, if necessary, other additives such as a colorant and a mold release agent, and a binder resin. It is preferably composed of a composed coating layer.

(External agent)
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. _{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 should be hydrophobized. The hydrophobizing treatment is performed, for example, by immersing the inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

Examples of the external additive include resin particles (resin particles such as polystyrene, polymethylmethacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, fluoropolymers). Particles) and the like.

The amount of the external additive added is preferably, for example, 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 manufacturing method>
Next, a method for producing toner according to this embodiment will be described.
The toner according to the present embodiment can be obtained by externally adding an external additive to the toner particles after producing the toner particles.

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

Specifically, for example, when the toner particles are produced by the aggregation and coalescence method,
A step of preparing a resin particle dispersion liquid in which resin particles to be a binder resin are dispersed (resin particle dispersion liquid preparation step) and a step of preparing the resin particle dispersion liquid and in the resin particle dispersion liquid (after mixing other particle dispersion liquids as necessary). (In the dispersion), resin particles (other particles if necessary) are agglomerated to form agglomerated particles (aggregated particle forming step), and the agglomerated particle dispersion in which the agglomerated particles are dispersed is heated. , Agglomerated particles are fused and coalesced to form toner particles (fusion and coalescence step), and toner particles are manufactured.

The details of each step will be described below.
In the following description, a method of obtaining toner particles containing a colorant and a mold release agent will be described, but the colorant and the mold release agent are used as needed. Of course, other additives other than colorants and mold release agents may be used.

-Resin particle dispersion liquid preparation process-
First, together with the resin particle dispersion liquid in which the resin particles to be the binder resin are dispersed, for example, a colorant particle dispersion liquid in which the colorant particles are dispersed and a release agent particle dispersion liquid in which the release agent particles are dispersed are prepared. To do.

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

Examples of the dispersion medium used in the resin particle dispersion liquid include an aqueous medium.
Examples of the aqueous medium include distilled water, water such as ion-exchanged water, alcohols, and the like. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Examples thereof include nonionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include general dispersion methods such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion liquid by, for example, a phase inversion emulsification method.
In the phase inversion emulsification method, the 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 resin, and then the aqueous medium is used. A method in which the (W phase) is charged to convert the resin from W / O to O / W (so-called phase inversion) to discontinue the phase, and the resin is dispersed in an aqueous medium in the form of particles. Is.

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

The content of the resin particles contained in the resin particle dispersion is, for example, preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 45% by mass or less.

In the same manner as the resin particle dispersion, for example, a colorant particle dispersion and a release agent particle dispersion are also prepared. That is, regarding the volume average particle size, dispersion medium, dispersion method, and particle content of the particles in the resin particle dispersion, the colorant particles dispersed in the colorant particle dispersion and the release agent particle dispersion are used. The same applies to the disperse of the release agent particles.

-Agglomerated 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, the resin particles, the colorant particles, and the release agent particles are heteroaggregated to form the resin particles, the colorant particles, and the release agent particles having a diameter close to the diameter of the target toner particles. Form agglomerated particles containing.

Specifically, for example, a flocculant is added to the mixed dispersion, 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 particles are heated to a temperature of the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles is -30 ° C or higher and the glass transition temperature is -10 ° C or lower), and the particles dispersed in the mixed dispersion are aggregated. , Form agglomerated particles.
In the agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear type homogenizer, the above-mentioned flocculant is added at room temperature (for example, 25 ° C.), and the pH of the mixed dispersion is acidic (for example, pH is 2 or more and 5 or less). ), And if necessary, a dispersion stabilizer may be added, and then the above heating may be performed.

Examples of the flocculant include a surfactant used as a dispersant added to the mixed dispersion, a surfactant having the opposite polarity, an inorganic metal salt, and a divalent or higher 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 the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride and aluminum sulfate, and inorganics such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide. Examples include metal salt polymers.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid and gluconic acid, iminodic acid (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA).
The amount of the chelating agent added is, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

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

Toner particles are obtained through the above steps.
After obtaining the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed, the agglomerated 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 agglomerated particles. The step of aggregating so as to adhere to form the second agglomerated particles and the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed are heated to fuse and unite the second agglomerated particles. , Toner particles may be produced through the steps of forming toner particles having a core / shell structure.

Here, after the fusion / coalescence step is completed, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain toner particles in a dried state.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, air-flow drying, fluid drying, vibration-type fluid drying and the like may be performed.

Next, a case of producing a toner having toner particles containing a urea-modified polyester resin will be described.
Toner particles containing a urea-modified polyester resin as a binder resin may be obtained by the following dissolution / suspension method. Although a method for obtaining toner particles containing an unmodified polyester resin and a urea-modified polyester resin as the binder resin will be described, the toner particles may contain only the urea-modified polyester resin as the binder resin.

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

The oil phase liquid is prepared by 1) a method of preparing by dissolving or dispersing the toner material in an organic solvent all at once, and 2) kneading the toner material in advance and then dissolving or dispersing this kneaded compound in an organic solvent. 3) A method of dissolving an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound in an organic solvent, and then dispersing a bright pigment and a mold release agent in the organic solvent to prepare the compound. 4) A method for preparing by dispersing a colorant and a mold release agent in an organic solvent, and then dissolving an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound in the organic solvent. 5) Toner particle materials (unmodified polyester resin, brilliant pigment, and mold release agent) other than the polyester prepolymer having an isocyanate group and the amine compound are dissolved or dispersed in an organic solvent, and then the organic solvent has an isocyanate group. Method for preparing by dissolving polyester prepolymer and amine compound, 6) Toner particle material (unmodified polyester resin, bright pigment, and mold release agent) other than polyester prepolymer or amine compound having isocyanate group is used as an organic solvent. Examples thereof include a method of preparing by dissolving or dispersing a polyester prepolymer having an isocyanate group or an amine compound in this organic solvent. The method for preparing the oil phase liquid is not limited to these.

Examples of the organic solvent of 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; and dichloromethane, chloroform, trichloroethylene and the like. Examples thereof include halogenated hydrocarbon solvents. It is preferable that these organic solvents dissolve the binder resin, dissolve in water at a rate of 0% by mass or more and 30% by mass or less, and have a boiling point of 100 ° C. or less. Among these organic solvents, ethyl acetate is preferable.

-Suspension preparation process-
Next, the obtained oil phase liquid is dispersed in the aqueous phase liquid to prepare a suspension (suspension preparation step).
Then, along with the preparation of the suspension, the reaction between the polyester prepolymer having an isocyanate group and the amine compound is carried out. Then, a urea-modified polyester resin is produced by this reaction. This reaction involves at least one of a molecular chain cross-linking reaction and an extension reaction. The reaction between the polyester prepolymer having an isocyanate group and the amine compound may be carried out together with the organic solvent removing step described later.
Here, the reaction conditions are selected based on the reactivity of the isocyanate group structure of the polyester prepolymer with the amine compound. As an example, the reaction time is preferably 10 minutes or more and 40 hours or less, and preferably 2 hours or more and 24 hours or less. 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. A known catalyst (dibutyltin laurate, dioctyltin laurate, etc.) may be used to produce the urea-modified polyester resin, if necessary. 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. Further, as the aqueous phase liquid, an aqueous phase liquid in which a particle dispersant is dispersed in an aqueous solvent and a polymer dispersant is dissolved in an aqueous solvent can also be mentioned. A well-known additive such as a surfactant may be added to the aqueous phase liquid.

Examples of the aqueous solvent include water (usually ion-exchanged water, distilled water, pure water). The aqueous solvent is a solvent containing water and an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellsolves (methylcellsolve, etc.), lower ketones (acetone, methylethylketone, etc.). There may be.

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

Examples of the inorganic particle dispersant include a hydrophilic inorganic particle dispersant. Specific examples of the inorganic particle dispersant include particles such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, clay, diatomaceous earth, and bentonite, and calcium carbonate particles are preferable. As the inorganic particle dispersant, one type may be used alone, or two or more types may be used in combination.

The surface of the particle dispersant may be surface-treated with a polymer having a carboxyl group.
As the polymer having a carboxyl group, the carboxyl group of α, β-monoethylene unsaturated carboxylic acid or α, β-monoethylene unsaturated carboxylic acid is made of alkali metal, alkaline earth metal, ammonium, amine or the like. Examples include 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-monoethylene unsaturated carboxylic acid esters. Be done. As the polymer having a carboxyl group, the carboxyl group of the copolymer of α, β-monoethylene unsaturated carboxylic acid and α, β-monoethylene unsaturated carboxylic acid ester is an alkali metal or an alkaline earth metal. , Alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc., which are neutralized with ammonium, amines and the like. As the polymer having a carboxyl group, one type may be used alone, or two or more types may be used in combination.

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

Examples of the polymer dispersant include hydrophilic polymer dispersants. Specific examples of the polymer dispersant include water-soluble polymer dispersants (for example, carboxymethyl cellulose, carboxyethyl cellulose, etc.) having a carboxyl group and no parent oil group (hydroxypropoxy group, methoxy group, etc.). Sexual cellulose ether).

-Solvent removal process-
Next, the organic solvent is removed from the obtained suspension to obtain a toner particle dispersion (solvent removal step). This solvent removing step is a step of removing the organic solvent contained in the droplets of the aqueous phase liquid dispersed in the suspension to generate toner particles. The removal of the organic solvent from the suspension may be carried out immediately after the suspension preparation step, or may be carried out one minute or more after the completion of the suspension preparation step.
In the solvent removing step, it is preferable to remove the organic solvent from the suspension by cooling or heating the obtained suspension to, for example, 0 ° C. or higher and 100 ° C. or lower.

Specific methods for removing the organic solvent include the following methods.
(1) A method of forcibly updating the gas phase on the suspension surface by blowing an air flow 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 suspension surface may be forcibly renewed by filling with gas, or gas may be further blown into the suspension.

Toner particles are obtained through the above steps.
Here, after the solvent removal step is completed, the toner particles formed in the toner particle dispersion liquid are subjected to a known washing step, solid-liquid separation step, and drying step to obtain toner particles in a dried state.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability.
The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, flash jet drying, fluid drying, vibration-type fluid drying and the like may be performed.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive to the obtained dry toner particles and mixing them. The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like. Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine or the like.

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

The carrier is not particularly limited, and examples thereof include known carriers. As the carrier, for example, a coating carrier in which the surface of a core material made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; a porous magnetic powder is impregnated with resin. Resin-impregnated carrier; etc.
The magnetic powder dispersion type carrier and the resin impregnated type carrier may be carriers 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. Of these, ferrite is preferable.

Examples of the conductive particles include metals such as gold, silver and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate and potassium titanate.
Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylic acid ester. Examples thereof include a copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polypropylene, a phenol resin, an epoxy resin and the like.
The coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include metals such as gold, silver and copper, and particles such as 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 resin and, if necessary, a coating layer forming solution in which various additives are dissolved in an appropriate solvent can 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 a coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the core material surface, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a solution for forming a coating layer is sprayed, a kneader coater method in which a core material of a carrier and a solution for forming a coating layer are mixed in a kneader coater, and a 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, preferably 0.4 μm or more, from the viewpoint of adhesion of the external additive to the carrier surface and removability. It is more preferably 1.5 μm or less, and particularly preferably 0.4 μm or more and 0.8 μm or less.
Further, 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, and more preferably 1.0 μm or more and 3.5 μm or less, from the viewpoint of chargeability. It is particularly preferably 2.0 μm or more and 3.0 μm or less.

In the present embodiment, the surface roughness indexes Ra and Sm of the carrier shall be measured by the following methods.
The Ra (arithmetic mean roughness) of the carrier surface is measured by using 2,000 carriers and an ultra-depth color 3D shape measurement microscope (VK9700, manufactured by KEYENCE CORPORATION) and converting the surface at a magnification of 1,000 times. It is a method of obtaining the above, and it is performed according to JIS B0601 (1994 version). Specifically, for Ra on the carrier surface, a roughness curve is 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 totaled. Obtained by averaging. The reference length for determining Ra on the carrier surface is 10 μm, and the cutoff value is 0.08 mm.
As a method for measuring Sm (average spacing of irregularities) on the carrier surface, 2,000 carriers and FE-SEM (S4100, manufactured by Hitachi High-Technologies Corporation) are used, and the surface is converted at a magnification of 3,500. This is a method of obtaining the above method, and is performed according to JIS B0601 (1994 version). Specifically, the Sm of the carrier surface is the interval of one cycle of Yamatani obtained from the three-dimensional shape of the carrier surface observed with the microscope and the intersection of the roughness curves with the average line. It is calculated by the average value. The reference length for determining the Sm of the carrier surface is 10 μm, and the cutoff value is 0.08 mm.

The method for producing a carrier satisfying Ra and Sm is not particularly limited, but the carrier can be produced, for example, as follows.

The surface roughness of the carrier (average surface roughness interval 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 fabrication of ferrite particles, but the main purpose of firing is magnetic 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 produced by the combination of the following (A) to (E).
(A) Temporary firing is performed before firing.
(B) Further pulverization is performed, and granulation is performed from a slurry having a pulverized particle size adjusted.
(C) SiO ₂ , SrCO _3, etc. are used as the surface conditioner.
(D) Adjusting the temperature and oxygen concentration at the time of firing (E) The magnetic particles obtained by firing are given a temperature while flowing.

After tentative firing before firing, it is crushed to control the particle size. Granulate into a pulverized product having the desired particle size and determine the volume average particle size. The size of the grain boundaries, which are the basis of magnetic particles, is controlled by the crushed particle size after calcination. 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 area of grain boundaries becomes wider and Sm can be adjusted to be larger. SrCO ₃ has the effect of increasing Ra.

Next, firing is performed, the temperature and oxygen concentration are adjusted, and the magnetization is matched to obtain ferrite. When the firing temperature is high, Sm tends to be large, and when 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 the firing is completed and the ferrite formation is performed, the internal voids are reduced at a temperature at which the ferrite formation reaction does not occur. As a result, the desired magnetic particles can be obtained.

From the viewpoint of image density uniformity, the average particle size of the number of carriers in the present 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. ..

The method for measuring the number average particle size of carriers in this embodiment is shown below.
A Coulter Multisizer II (manufactured by Beckman Coulter) is used as a measuring device, and ISOTON-II (manufactured by Beckman Coulter) is used as an electrolytic solution. First, a surfactant, preferably an alkylbenzene sulfone, is used as a dispersant. 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5 mass% aqueous solution of sodium acid, and this is added to 100 ml or more and 150 ml or less of the electrolytic solution. The electrolytic solution in which this measurement sample is suspended is dispersed for about 1 minute with an ultrasonic disperser, and the particle size is 2.0 μm or more and 60 μm or less using the aperture with an aperture diameter of 100 μm by the Coulter Multisizer II. Measure the particle size distribution of the particles in the range of. The number of particles to be measured is 50,000.
For the measured particle size distribution, a cumulative distribution is drawn from the small particle size side for the number of divided particle size ranges (channels), and the particle size with a cumulative total of 50% 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 device / 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 holder, a charging means for charging the surface of the image holder, a static charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge. A developing means that accommodates an image developer and develops an electrostatic charge image formed on the surface of the image holder as a toner image by the static charge image developer, and a recording medium that records the toner image formed on the surface of the image holder. It is provided with a transfer means for transferring to the surface of the recording medium and a fixing means for fixing the toner image transferred to the surface of the recording medium. Then, as the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

In the image forming apparatus according to the present embodiment, a charging step of charging the surface of the image holder, a static charge image forming step of forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge according to the present embodiment. A development step of developing an electrostatic charge image formed on the surface of an image holder as a toner image with an image developer, and a transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium. An image forming method (image forming method according to the present embodiment) having a fixing step of fixing a toner image transferred to the surface of a recording medium is carried out.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image holder to the recording medium; the toner image formed on the surface of the image holder is transferred to the intermediate transfer body. An intermediate transfer type device that first transfers the toner image to the surface and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium; after transferring the toner image, cleans the surface of the image holder before charging. A device provided with a cleaning means; a well-known image forming device such as a device provided with a static elimination means for irradiating the surface of an image holder with static elimination light after transfer of a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer means is, for example, an intermediate transfer body in which a toner image is transferred to the surface and a primary transfer in which a toner image formed on the surface of an image holder is primarily transferred to the surface of the intermediate transfer body. A configuration comprising means and secondary transfer means for secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium is applied.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) that is attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge including a developing means 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 shown, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the other parts will be omitted.

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is an electrophotographic first to output an image of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. A fourth image forming unit 10Y, 10M, 10C, 10K (image forming means) is provided. These image forming units (hereinafter, may be simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

An intermediate transfer belt 20 as an intermediate transfer body is extended through each unit above the drawings of each unit 10Y, 10M, 10C, and 10K. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 arranged apart from each other from the left to the right in the figure and a support roll 24 in contact with the inner surface of the intermediate transfer belt 20, and the first unit 10Y to the fourth unit 10Y to the fourth. It is designed to run in the direction toward the unit 10K. A force is applied to the support roll 24 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. Further, an intermediate transfer body cleaning device 30 is provided on the side surface of the image holder of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, the developing devices (development means) 4Y, 4M, 4C, and 4K of each unit 10Y, 10M, 10C, and 10K each have yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. Toner containing the four colors of toner is supplied.

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit forming a yellow image arranged on the upstream side in the traveling direction of the intermediate transfer belt. 10Y will be described as a representative. The second to fourth units are provided with reference numerals having magenta (M), cyan (C), and black (K) instead of yellow (Y) in the portion equivalent to the first unit 10Y. The description of the units 10M, 10C, and 10K of the above is omitted.

The first unit 10Y has a photoconductor 1Y that acts as an image holder. Around the photoconductor 1Y, a charging roll (an example of charging means) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and a laser beam 3Y based on a color-separated image signal expose the charged surface. An exposure device (an example of a static charge image forming means) 3 for forming an electrostatic charge image, and a developing device (an example of a developing means) 4Y for developing a static charge image by supplying a charged toner to the static charge image. A primary transfer roll 5Y (an example of a primary transfer means) that transfers a toner image onto an intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning means) 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 arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoconductor 1Y. Further, a bias power supply (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 supply changes the transfer bias applied to each primary transfer roll by control by a control unit (not shown).

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

The static charge image is an image formed on the surface of the photoconductor 1Y by charging. The laser beam 3Y reduces the specific resistance of the irradiated portion of the photosensitizer layer, and the charged charge on the surface of the photoconductor 1Y flows. On the other hand, it is a so-called negative latent image formed by the residual charge of the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoconductor 1Y is rotated to a predetermined development position as the photoconductor 1Y travels. Then, at this developing position, the electrostatic charge image on the photoconductor 1Y is converted into a visible image (developed image) as a toner image by the developing device 4Y.

In the developing apparatus 4Y, for example, a static charge image developing agent containing at least yellow toner and a carrier is housed. The yellow toner is triboelectrically charged by being agitated inside the developing apparatus 4Y, and has a charge having the same polarity (negative electrode property) as the charged charge on the photoconductor 1Y, and is a developer roll (developing agent holder). Example) It is held on. Then, as the surface of the photoconductor 1Y passes through the developing device 4Y, the yellow toner is electrostatically adhered to the statically eliminated latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. .. The photoconductor 1Y on which the yellow toner image is formed is continuously traveled at a predetermined speed, and the toner image developed on the photoconductor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is transferred to the primary transfer, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roll 5Y is applied to the toner image to act on the photoconductor. The toner image on 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is 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 photoconductor 1Y is removed by the photoconductor cleaning device 6Y and recovered.

Further, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
In this way, the intermediate transfer belt 20 to which the yellow toner image is transferred in the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of each color are superimposed and multiple transferred. Toner.

The intermediate transfer belt 20 on which four color toner images are multiplex-transferred through the first to fourth units is arranged on the image holding surface side of the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt, and the intermediate transfer belt 20. It leads to a secondary transfer unit composed of the secondary transfer roll (an example of the secondary transfer means) 26. On the other hand, the recording paper (an example of the recording medium) P is fed to the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact with each other via the supply mechanism at a predetermined timing, and the secondary transfer bias is supported by the support roll. It is applied to 24. The transfer bias applied at this time has a (-) polarity that is the same 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, and the transfer bias is applied on the intermediate transfer belt 20. The toner image of is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by the resistance detecting means (not shown) for detecting the resistance of the secondary transfer unit, and is voltage controlled.

After that, the recording paper P is sent to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (an example of the fixing means) 28, and the toner image is fixed on the recording paper P to form the fixing image.

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

The recording paper P for which the color image has been fixed is carried out toward the ejection 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 contains the electrostatic charge image developer according to the present embodiment, and is a developing means for developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developer. It is a process cartridge that is attached to and detached from the image forming apparatus.

The process cartridge according to the present embodiment is not limited to the above configuration, and includes a developing device and other means such as an image holder, a charging means, an electrostatic charge image forming means, and a transfer means, if necessary. It may be configured to include at least one selected from.

Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited to this. The main parts shown in the figure will be described, and the other parts will be omitted.

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 (an example of an image holder) and the photoconductor 107 by, for example, a housing 117 provided with a mounting rail 116 and an opening 118 for exposure. The charged roll 108 (an example of the charging means), the developing device 111 (an example of the developing means), and the photoconductor cleaning device 113 (an example of the cleaning means) are integrally combined and held and configured to form a cartridge. There is.
In FIG. 2, 109 is an exposure device (an example of an electrostatic charge image forming means), 112 is a transfer device (an example of a transfer means), 115 is a fixing device (an example of a fixing means), and 300 is a recording paper (an example of a recording medium). An example) is shown.

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present embodiment is a toner cartridge that houses the toner according to the present embodiment and is attached to and detached from the image forming apparatus. The toner cartridge accommodates a replenishing toner for supplying 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 structure in which the toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing apparatus 4Y, 4M, 4C, and 4K are each developing apparatus (color). ) Is connected to a toner cartridge (not shown). Further, when the amount of toner contained in the toner cartridge is low, the toner cartridge is replaced.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited to the following Examples. Unless otherwise specified, "parts" and "%" represent "parts by mass" and "% by mass".

[Preparation of resin particle dispersion (A)]
・ Telephthalic acid: 30 mol parts ・ Fumaric acid: 70 mol parts ・ Bisphenol A ethylene oxide adduct: 12 mol parts ・ Bisphenol A propylene oxide adduct: 88 mol parts Stirrer, nitrogen introduction pipe, temperature sensor and rectification tower The above-mentioned material was charged into the provided flask, the temperature was raised to 210 ° C. over 1 hour, and 1 part of titanium tetraethoxydo was added to 100 parts of the above-mentioned material. The temperature was raised to 230 ° C. over 0.5 hours while distilling off the generated water, and the dehydration condensation reaction was continued at that temperature for 1 hour, and then the reaction product was cooled. In this way, the polyester resin (A) was synthesized.
40 parts of ethyl acetate and 25 parts of 2-butanol were added to a container equipped with a temperature control means and a nitrogen substitution means to prepare a mixed solvent, and then 100 parts of the polyester resin (A) was gradually added to dissolve the mixture. A 10 mass% aqueous ammonia solution (equivalent to 3 times the molar ratio of 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 emulsify. After completion of the dropping, the emulsion is returned to room temperature (20 ° C to 25 ° C) and bubbling with dry nitrogen for 48 hours with stirring 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 liquid (A) having a volume average particle size of 190 nm.

[Preparation of resin particle dispersion (B)]
・ Dodecanedioic acid (1,10-decandicarboxylic acid): 50 mol parts ・ 1,9-nonanediol: 50 mol parts Put the above monomer component in a reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas introduction tube. After the reaction vessel was replaced with dry nitrogen gas, 0.25 part of titanium tetrabutoxide (reagent) was added to 100 parts of the monomer component. After a stirring reaction at 170 ° C. for 3 hours under a nitrogen gas stream, the temperature was further raised to 220 ° C. over 1 hour, the inside of the reaction vessel was reduced to 3 kPa, and the reaction was stirred under reduced pressure for 13 hours to make polyester. Resin (B) was obtained.
A reaction tank with a jacket (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dropping device, and an anchor wing, 300 parts of polyester resin (B), 160 parts of methyl ethyl ketone (solvent), and 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 circulation type constant temperature bath (dissolution solution preparation step).
After that, the stirring rotation speed was set to 150 rpm, the water circulation type constant temperature bath 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. was added. A total of 900 parts were added dropwise at a rate of / min to invert the phase to obtain an emulsion.
Immediately, 800 parts of the obtained emulsion 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, it was heated in a hot water bath at 60 ° C., and the pressure was reduced to 7 kPa while paying attention to sudden boiling to remove the solvent. When the amount of solvent recovered reached 1,100 parts, the pressure was returned to normal pressure, and the eggplant flask was water-cooled to obtain a dispersion. The obtained dispersion had no solvent odor. The volume average particle diameter D50v of the resin particles in this dispersion was 130 nm. Then, ion-exchanged water was added to prepare the solid content concentration to 20% by mass, which was used as the resin particle dispersion liquid (B).

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

[Preparation of colorant particle dispersion (1)]
-Regal330 (manufactured by Cabot): 50 parts-Ionic surfactant Neogen RK (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 5 parts-Ion-exchanged water: 200 parts Mix the above components and Ultimizer (Co., Ltd.) A colorant particle dispersion (solid content concentration: 20% by mass) was prepared by treating with (manufactured by Sugino Machine) at 240 MPa for 10 minutes.

[Preparation of toner particles 1]
-Resin particle dispersion (A): 400 parts by mass-Resin particle dispersion (B): 300 parts by mass-Removing agent particle dispersion (1): 50 parts by mass-Colorant particle dispersion (1): 50 mass 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 (Ultratalax T50 manufactured by IKA). Next, 1.75 parts of a 10% aqueous nitric acid solution of polyaluminum chloride was gradually added dropwise as a coagulant, and the homogenizer was dispersed at 5,000 rpm for 15 minutes to prepare a raw material dispersion.
After that, the raw material dispersion was transferred to a stirrer using a stirrer with four paddles and a polymerization kettle equipped with a thermometer, and the stirring speed was set to 700 rpm to start heating with a mantle heater and aggregated at 45 ° C. Promoted the growth of particles. At this time, the pH of the dispersion was controlled in the range of 2.2 to 3.5 by using 0.3 N nitric acid or 1 N sodium hydroxide aqueous solution. It was kept in the above pH range for about 2 hours to form aggregated particles.
Next, 200 parts of the resin particle dispersion liquid (A) was additionally added to attach the resin particles of the binding resin to the surface of the aggregated particles. The temperature was further raised to 47 ° C., and the aggregated particles were prepared while checking the size and morphology of the particles with an optical microscope and Multisizer II. Then, 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 with a 5% aqueous sodium hydroxide solution and held for 15 minutes. Then, the pH was raised to 8.0 in order to fuse the agglomerated particles, and then the temperature was raised to 85 ° C. After confirming that the agglomerated particles were fused with an optical microscope, the mixture was cooled at a temperature lowering rate of 1.0 ° C./min. Then, it was sieved with a 20 μm mesh, washed with water repeatedly, and then dried with a vacuum dryer to obtain toner particles 1. The volume average particle diameter of the obtained toner particles 1 was 5.6 μm, and the average circularity was 0.965.

[Preparation of small diameter toner particles 1]
-Resin particle dispersion liquid (A): 600 parts by mass-Resin particle dispersion liquid (B): 300 parts by mass-Release agent particle dispersion liquid (1): 50 parts by mass-Colorant particle dispersion liquid (1): 50% by mass 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 (Ultratalax T50 manufactured by IKA). Next, 0.3 part of a 10% aqueous nitric acid solution of polyaluminum chloride was gradually added dropwise as a coagulant, and the homogenizer was dispersed at 5,000 rpm for 15 minutes to prepare a raw material dispersion.
After that, the raw material dispersion was transferred to a stirrer using a stirrer with four paddles and a polymerization kettle equipped with a thermometer, and the stirring speed was set to 700 rpm to start heating with a mantle heater and aggregated at 45 ° C. Promoted the growth of particles. At this time, the pH of the dispersion was controlled in the range of 3.8 to 5.0 by using 0.3 N nitric acid or 1 N sodium hydroxide aqueous solution. It was kept in the above pH range for about 30 minutes to form aggregated particles.
Then, 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 with a 5% aqueous sodium hydroxide solution and held for 15 minutes. Then, the pH was raised to 8.0 in order to fuse the agglomerated particles, and then the temperature was raised to 85 ° C. After confirming that the agglomerated particles were fused with an optical microscope, the mixture was cooled at a temperature lowering rate of 1.0 ° C./min. Then, it was sieved with a 20 μm mesh, washed with water repeatedly, and then dried with a vacuum dryer to obtain small-diameter toner particles 1. The volume average particle diameter of the obtained small-diameter toner particles 1 was 1.6 μm, and the average circularity was 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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. Toner 1 was obtained.

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

<Making carrier a>
-Ferrite core material 1: 100 parts-Methyl methacrylate / dimethyl amino methacrylate copolymer (copolymerization ratio 95: 5, mol ratio): 3 parts-Carbon black (VXC72, manufactured by Cabot): 0.3 parts-Toluene: 14 parts Of the components shown in the above carrier composition, each component except the ferrite core material 1 and glass beads (φ1 mm, the same amount as toluene) were stirred at 1,200 ppm / 30 min using a sand mill manufactured by Kansai Paint Co., Ltd. , The resin coating layer forming solution 1. Further, the resin coating layer forming solution 1 and the ferrite core material 1 were placed in a vacuum degassing type kneader and toluene was distilled off to form a resin-coated carrier. Carrier a was obtained by subsequently removing fine powder / coarse powder with an elbow jet. As a result of image analysis described later, the number average particle size was 34 μm, Ra = 0.6 μm, and Sm = 2.5 μm.

[Preparation of developer 1]
Seven parts of toner 1 was mixed with 100 parts of carrier a, stirred at 40 rpm for 20 minutes 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 preparation of the toner particles 1, the toner particles 2 to 7 having different volume average particle diameters and average circularities were obtained by changing the time for holding aggregation at 45 ° C. and the time for fusion at 85 ° C. The volume average particle size and the average circularity of each toner particle were as follows.
The volume average particle size of the toner particles 2 was 6.8 μm, and the average circularity was 0.960.
The volume average particle size of the toner particles 3 was 5.2 μm, and the average circularity was 0.962.
The volume average particle size of the toner particles 4 was 7.5 μm, and the average circularity was 0.962.
The volume average particle size of the toner particles 5 was 4.8 μm, and the average circularity was 0.957.
The volume average particle size of the toner particles 6 was 5.6 μm, and the average circularity was 0.930.
The volume average particle size of the toner particles 7 was 5.6 μm, and the average circularity was 0.985.

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

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

[Preparation 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 = 0.9 μm, and Sm = 3.2 μm.

(Preparation of resin particle dispersion liquid 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 Dodecanthiol (manufactured by Wako Pure Chemical Industries, Ltd.): 0.4 parts by mass

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

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

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

The obtained resin particles were found to be 250 nm when the volume average particle size D50v of the resin particles was measured with a laser diffraction type particle size distribution measuring device LA-700 (manufactured by HORIBA, Ltd.). The glass transition point of the resin was measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC-50, manufactured by Shimadzu Corporation) and found to be 53 ° C. Further, the number average molecular weight (in terms of polystyrene) was measured using a molecular weight measuring device (HLC-8020, manufactured by Tosoh Corporation) using THF as a solvent and found to be 13,000. 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 mass Colorant particle dispersion: 50 parts by mass Release agent particle dispersion (1): 50 parts by mass Polyaluminum chloride: 0.4 parts by mass

The above components were sufficiently mixed and dispersed in a stainless steel flask using Ultratarax manufactured by IKE, and then the flask was heated to 48 ° C. while stirring in a heating oil bath. After holding at 48 ° C. for 80 minutes, 100 parts by mass of the same resin particle dispersion liquid A as described above was slowly added thereto.

Then, after adjusting the pH in the system to 6.0 using an aqueous sodium hydroxide solution having a concentration of 0.5 mol / L, the stainless steel flask was sealed, the stirring shaft was magnetically sealed, and stirring was continued. It was heated to 97 ° C. and held for 3 hours. After completion of the reaction, the temperature was lowered at 1 ° C./min, and the mixture was filtered and sufficiently washed with ion-exchanged water, and then solid-liquid separation was performed by Nucci-type 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 repeated 5 more times, and when the pH of the filtrate became 6.54 and the electric conductivity was 6.5 μS / cm, the No. 1 was obtained by suction filtration using the Nutche type. Solid-liquid separation was performed using 5A filter paper. Then, vacuum drying was continued for 12 hours to obtain toner particles 8.

The volume average particle size of the toner particles 8 was 5.6 μm, and the average circularity was 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 size 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 heating and mixing the above components at 180 ° C, add 3 parts of dibutyltin oxide to 220 Water was distilled off while heating at ° 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 the cyclohexanone solution, and the mixture was heated at 130 ° C. Further, this solution was heated under reduced pressure to remove the solvent and unreacted acid to obtain an unmodified polyester resin (1). The glass transition temperature of the obtained unmodified polyester resin (1) was 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 heating and mixing the above components at 180 ° C, add 3 parts of dibutyltin oxide to 220 Water was distilled off while heating at ° C. to obtain a polyester prepolymer. 350 parts of the obtained polyester prepolymer, 50 parts of tolylene diisocyanate, and 450 parts of ethyl acetate are placed in a container, and the mixture is heated at 130 ° C. for 3 hours to obtain a polyester prepolymer (1) having an isocyanate group (hereinafter, "" Isocyanate-modified polyester prepolymer (1) ") was obtained.

(Preparation of ketimine compound (1))
50 parts of methyl ethyl ketone and 150 parts of hexamethylenediamine were placed in a container and stirred at 60 ° C. to obtain ketimine compound (1).

[Preparation of colorant particle dispersion (2)]
-Regal330 (manufactured by DIC Cabot Corporation): 10 parts-Ethyl acetate: 90 parts With the above components cooled to 10 ° C, wet pulverization with a microbead type disperser (DCP mill), colorant particle dispersion liquid (2) was obtained.

(Preparation of release agent particle dispersion liquid (2))
-Fischer-Tropsch wax (FNP-0090 manufactured by Nippon Seiwa Co., Ltd., melting temperature 90 ° C.): 30 parts-Ethyl acetate: 270 parts Microbead type disperser (DCP mill) with the above components cooled to 10 ° C. Wet pulverization with the above to obtain a release agent particle dispersion liquid (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) 75 were added to the obtained mixture. Parts were added and stirred to obtain an oil phase liquid (1).

(Preparation of styrene acrylic resin particle dispersion liquid (1))
-Styline: 370 parts-n-Butyl acrylate: 30 parts-Acrylic acid: 4 parts-Dodecanethiol: 24 parts-Carbon bromide: 4 parts A mixture obtained by mixing and dissolving the above components is used as a nonionic surfactant. (Sanyo Kasei Kogyo Co., Ltd .: Nonipol 400) 6 parts and anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts dissolved in 560 parts of ion-exchanged water in an aqueous solution in a flask After dispersion and emulsion, while mixing for 10 minutes, an aqueous solution prepared by dissolving 4 parts of ammonium persulfate in 50 parts of ion-exchanged water was added thereto, and after nitrogen substitution, the contents were 70 while stirring the inside of the flask. The mixture was heated in an oil bath until the temperature reached ℃, and the emulsion polymerization was continued for 5 hours. In this way, a styrene acrylic resin particle dispersion liquid (1) (resin particle concentration: 40% by mass) was obtained by dispersing resin particles having an average particle size of 180 nm and a weight average molecular weight (Mw) of 15,500. 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 cellogen BS-H (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 200 parts ・ Ion-exchanged water: 200 parts Stirring and mixing the above components, water A phase solution (1) was obtained.

-Preparation of toner particles 9-
-Oil phase liquid (1): 300 parts-Isocyanate-modified polyester prepolymer (1): 25 parts-Ketimine compound (1): 0.5 parts Put the above ingredients in a container and homogenizer (Ultra Tarax T50, manufactured by IKA). ) Was stirred for 2 minutes to obtain an oil phase solution (1P), 1,000 parts of the aqueous phase solution (1) was added to the container, and the mixture was stirred with a homogenizer for 20 minutes. Next, the mixed solution was 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 granules. Next, the granules were washed with water, dried and classified to obtain toner particles 9.
The volume average particle diameter of the obtained toner particles 9 was 5.6 μm, and the average circularity was 0.961.

[Preparation of small diameter toner particles 9]
After obtaining toner particles in the same manner as in producing the toner particles 9, the large-diameter particles were removed by 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. ..

[Preparation 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 with a Henschel mixer. Mixing for 2 minutes gave toner 2.

[Preparation 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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. 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 with a Henschel mixer. Mixing for 2 minutes gave toner 4.

[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 with a Henschel mixer. Mixing for 2 minutes gave toner 5.

[Preparation 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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. 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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. 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 with a Henschel mixer. Mixing for 2 minutes gave toner 8.

[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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. Toner 9 was obtained.

[Preparation 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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. 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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. 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 with a Henschel mixer. Mixing for 2 minutes gave toner 12.

[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 with a Henschel mixer. Mixing for 2 minutes gave toner 13.

[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 with a Henschel mixer. Mixing for 2 minutes gave toner 14.

[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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. 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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. 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 with a Henschel mixer at a peripheral speed of 30 m / s for 2 minutes. Toner 17 was obtained.

[Preparation of developing agents 2 to 18]
Developers 2 to 18 were prepared in the same manner as in the preparation of developer 1 using the toners and carriers shown in Table 1.

(Measuring method of number particle size distribution, volume particle size distribution, volume average particle size and average circularity of toner particles)
The measurement was performed by the above-mentioned measuring method using a flow-type particle image analyzer FPIA-3000 (manufactured by Sysmex Corporation).

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

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

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

1Y, 1M, 1C, 1K photoconductor (example of image holder)
2Y, 2M, 2C, 2K charging roll (example of charging means)
3 Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K laser beam 4Y, 4M, 4C, 4K developing device (example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (example of primary transfer means)
6Y, 6M, 6C, 6K Photoreceptor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner Cartridge 10Y, 10M, 10C, 10K Image Forming Unit 20 Intermediate Transfer Belt (Example of Intermediate Transfer)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photoreceptor (example of image holder)
108 Charging roll (an example of charging means)
109 Exposure device (an example of static charge image forming means)
111 Developing equipment (an example of developing means)
112 Transfer device (an example of transfer means)
113 Photoreceptor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Mounting rail 117 Housing 118 Opening for exposure 200 Process cartridge 300 Recording paper (an example of recording medium)
P Recording paper (an example of recording medium)

Claims (11)

It has at least toner particles containing a binder resin and a colorant, and an external additive.
The binder resin contains an amorphous polyester resin and a crystalline polyester resin.
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 5% or more and 60% or less with respect to the entire toner particles, and the toner particles having a particle size of more than 2 μm and 50 μm or less. The ratio is 40% or more and 95% or less with respect to the entire toner particles.
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 0.6% or more and 14 % or less with respect to the entire toner particles, and the toner having a particle size of more than 2 μm and 50 μm or less. A toner for static charge image development in which the ratio of particles is 86 % or more and 99.4% or less with respect to the entire toner particles. The static charge image development according to claim 1, wherein the toner particle number particle size distribution has at least 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. toner. The toner for static charge image development according to claim 1 or 2, wherein the volume average particle diameter of the toner particles is 4 μm or more and 10 μm or less. The toner for static charge image development according to any one of claims 1 to 3, wherein the average circularity of the toner particles having a particle size of 0.5 μm or more and 2 μm or less is 0.940 or more and 0.995 or less. Claims 1 to 0.050, where C1 is the average circularity of the toner particles having a particle size of 0.5 μm or more and 2 μm or less, and C2 is the average circularity of all the toner particles. Item 4. The toner for developing an electrostatic charge image according to any one of 4. An electrostatic charge image developer comprising a carrier and the toner for electrostatic charge image developing 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 carriers is 15 μm or more and 70 μm or less. The toner for developing an electrostatic charge image according to any one of claims 1 to 5 is accommodated.
A toner cartridge that is attached to and detached from the image forming device. A developing means for accommodating the electrostatic charge image developing agent according to claim 6 or 7 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided.
A process cartridge that is attached to and detached from the image forming device. Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means that accommodates the electrostatic charge image developer according to claim 6 or 7, and develops the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
An image forming apparatus comprising. The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using 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 holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
An image forming method having.