JP6872112B2 - 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 recent years, in image formation by the electrophotographic method, in addition to cyan (C), magenta (M), yellow (Y), and black (K) toners for forming black images and multicolor (color) images. Also, a white (W) toner for forming a white image is used.

For example, Patent Document 1 states that "at least a binder resin, a white pigment, and a release agent are contained, and the white pigment is dispersed in the binder resin in a state of being coated with the release agent. White toner for developing static charge images "is disclosed.

Further, Patent Document 2 states that "at least an organic solvent phase in which a functional group-containing polyester resin is dissolved, an active hydrogen-containing compound, and a colorant are dispersed in an aqueous medium phase in which resin particles are dispersed. It is a toner for static charge image development that causes an extension reaction and a cross-linking reaction between the functional group-containing polyester resin and the active hydrogen-containing compound, and removes an organic solvent from the obtained dispersion liquid to serve as a toner base. A white toner for developing an electrostatic charge image using a polyol-coated titanium oxide pigment as the colorant is disclosed.

Japanese Unexamined Patent Publication No. 2014-016598 Japanese Unexamined Patent Publication No. 2010-008816

Conventionally, it has been required to increase the light reflectance from the viewpoint of color development in an image formed by a toner for developing an electrostatic charge image. Further, in a white toner for forming a white image, a glittering toner for forming a glittering image (an image having a metallic feeling) such as gold or silver, the color of the recording medium is reflected in the image. It is required to suppress this, that is, to have a concealing property, and from this viewpoint as well, it is required to increase the reflectance of light.
An object of the present invention is to have toner particles containing at least a crystalline resin and at least one pigment selected from an inorganic pigment and a metal pigment, from 0 ° C. to 150 ° C. at a heating rate of 10 ° C./min. When differential scanning calorimetry (DSC) is performed, which involves a temperature raising step of raising the temperature and a temperature lowering step of lowering the temperature from 150 ° C. to 0 ° C. at a temperature lowering rate of -10 ° C./min, the temperature is 55 ° C. or higher and 85 ° C. An image having a higher light reflectance than the case where the heat absorption peak Tm derived from the crystalline resin is present in the following regions and the exothermic peak Tc derived from the crystalline resin is not present in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature lowering step. It is an object of the present invention to provide a toner for developing an electrostatic charge image that can form the above.

The above problem is solved by the following means. That is,

The invention according to <1 > is
It has toner particles containing at least a crystalline resin and at least one pigment selected from inorganic pigments and metal pigments.
Differential scanning calorimetry (DSC) is a step of raising the temperature from 0 ° C. to 150 ° C. at a heating rate of 10 ° C./min and a step of lowering the temperature from 150 ° C. to 0 ° C. at a rate of lowering temperature of -10 ° C. In the heating step, the heat absorption peak Tm derived from the crystalline resin is present in the region of 55 ° C. or higher and 85 ° C. or lower, and the heat generated by the crystalline resin is generated in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature lowering step. A toner for developing an electrostatic charge image having a peak Tc.

The invention according to <2 > is
The toner for static charge image development according to < 1 > , wherein the peak calorific value Qc of the exothermic peak Tc is 5 × 10 ^-3 J / g or more and 10 J / g or less.

The invention according to <3 > is
The static charge according to < 1 > or < 2 > , wherein the ratio [Qc / Qm] of the peak calorific value Qc of the exothermic peak Tc to the peak calorific value Qm of the endothermic peak Tm is 5 × 10 ^-4 or more and 0.8 or less. Image development toner.

The invention according to <4 > is
The ratio [Qc / Cr] of the peak calorific value Qc of the exothermic peak Tc to the content Cr (mass%) of the crystalline resin in the toner particles is 5 × 10 ^-4 or more and 1.0 or less < 1 >. ~ <3> the toner according to any one of.

The invention according to <5 > is
<1> to an electrostatic image developer containing a toner for electrostatic image development according to any one of <4>.

The invention according to <6 > is
<1> to accommodate the toner for electrostatic image development according to any one of <4>,
A toner cartridge that is attached to and detached from the image forming device.

The invention according to <7 > is
A developing means for accommodating the electrostatic charge image developing agent according to < 5 > 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.

The invention according to <8 > is
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 for accommodating the electrostatic charge image developer according to < 5 > and developing 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 by heating,
An image forming apparatus comprising.

The invention according to <9 > is
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 < 5 >.
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 by heating, and
An image forming method having.

According to the invention according to < 1 > , in an embodiment containing toner particles containing at least a crystalline resin and at least one pigment selected from an inorganic pigment and a metal pigment, the temperature rise rate is 10 ° C./min and 0 ° C. When differential scanning calorimetry (DSC) is performed, in which a temperature raising step of raising the temperature from 150 ° C. to 150 ° C. and a temperature lowering step of lowering the temperature from 150 ° C. to 0 ° C. at a temperature lowering rate of -10 ° C./min are performed, 55 during the temperature raising step. Light reflection compared to the case where the heat absorption peak Tm derived from the crystalline resin is present in the region of ° C. or higher and 85 ° C. or lower and the exothermic peak Tc derived from the crystalline resin is not present in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature lowering step. An electrostatic charge image developing toner capable of forming an image having a high rate is provided.
According to the invention according to < 2 > , a toner for static charge image development capable of forming an image having high light reflectance as compared with the case where the peak calorific value Qc of the exothermic peak ^{is less than 5 × 10 -3 J / g is provided.} Will be done.
According to the invention according to < 3 > , an image having a higher light reflectance than the case where the ratio [Qc / Qm] of the peak heat quantity Qc of the exothermic peak to the peak heat quantity Qm of the endothermic peak ^{is less than 5 × 10 -4 is obtained.} Tone for static charge image development which can be formed is provided.
According to the invention according to < 4 > , light reflection is performed as compared with the case where the ratio [Qc / Cr] of the peak calorific value Qc of the exothermic peak to the content Cr in the toner particles of the crystalline resin ^{is less than 5 × 10 -4.} Toner for static charge image development capable of forming an image having a high rate is provided.

According to the invention according to < 5 > , < 6 > , < 7 > , < 8 > , or < 9 > , at least a crystalline resin and at least one pigment selected from inorganic pigments and metal pigments are included. In the embodiment having toner particles, a temperature raising step of raising the temperature from 0 ° C. to 150 ° C. at a heating rate of 10 ° C./min and a temperature lowering step of lowering the temperature from 150 ° C. to 0 ° C. at a temperature lowering rate of −10 ° C./min are performed. When differential scanning calorimetry (DSC) is performed, it has a heat absorption peak Tm derived from a crystalline resin in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature raising step, and in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature lowering step. Static charge image developer, toner cartridge, process cartridge, image forming apparatus, which can form an image with high light reflectance, as compared with the case of using only a static charge image developing toner having no exothermic peak Tc derived from a crystalline resin. Alternatively, an image forming method is provided.

It is a conceptual diagram of the graph which shows the measurement result in the temperature raising process by the differential scanning calorimetry (DSC) about the toner which concerns on this embodiment. It is a conceptual diagram of the graph which shows the measurement result in the temperature lowering process by the differential scanning calorimetry (DSC) about the toner which concerns on this embodiment. It is a conceptual diagram of the graph which shows the measurement result in the temperature raising process by the differential scanning calorimetry (DSC) about a conventional toner. It is a conceptual diagram of the graph which shows the measurement result in the temperature lowering process by the differential scanning calorimetry (DSC) about a conventional toner. It is a figure explaining the state of a screw about an example of the screw extruder used for manufacturing the toner which concerns on this embodiment. 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.

Hereinafter, the present invention will be described in detail by showing an embodiment as an example.

<Toner for static charge image development>
The toner for static charge image development according to the present embodiment (hereinafter, also simply referred to as “toner”) has toner particles containing at least a crystalline resin and at least one pigment selected from an inorganic pigment and a metal pigment. ..
Then, differential scanning calorimetry (differential scanning calorimetry) is performed by performing a heating step of raising the temperature from 0 ° C. to 150 ° C. at a heating rate of 10 ° C./min and a temperature lowering step of lowering the temperature from 150 ° C. to 0 ° C. at a temperature lowering rate of −10 ° C./min. In DSC), the heat absorption peak Tm derived from the crystalline resin is present in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature raising step, and the heat generated by the crystalline resin is generated in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature lowering step. It has a peak Tc.

By satisfying the above configuration, the toner according to the present embodiment achieves high light reflectance in the formed image.
The reason is presumed as follows.

Conventionally, in an image formed by toner, high light reflectance has been required from the viewpoint of exhibiting excellent color development. Further, particularly in a white toner for forming a white image, a glittering toner for forming a glittering image (an image having a metallic feeling) such as gold or silver, the color of the recording medium is an image. It is required to suppress the reflection on the image, that is, to have a concealing property, and from this viewpoint as well, it is required to achieve a high light reflectance, and further improvement is required.

On the other hand, the toner according to the present embodiment has an endothermic peak Tm derived from a crystalline resin in a region of 55 ° C. or higher and 85 ° C. or lower during the temperature raising step in the differential scanning calorimetry, and is derived from the crystalline resin during the temperature lowering step. Has an endothermic peak Tc.
According to the study by the present inventors, the conventionally used toner containing neither an inorganic pigment nor a metal pigment has a temperature of 55 ° C. or higher and 85 ° C. in the differential scanning calorimetry performed under the above conditions. It was clarified that the exothermic peak Tc derived from the crystalline resin did not appear in the following regions.

Here, a conceptual diagram of a graph by differential scanning calorimetry (DSC) for the toner according to the present embodiment and the conventional toner will be described.
1 and 2 are graphs showing the measurement results of the toner according to the present embodiment in the temperature raising step by differential scanning calorimetry (DSC) under the above conditions, and the graphs showing the measurement results in the temperature lowering step, respectively. It is a conceptual diagram. Further, FIGS. 3 and 4 are concepts of a graph showing the measurement results in the temperature raising step and a graph showing the measurement results in the temperature lowering step for the conventional toner by differential scanning calorimetry (DSC) under the above conditions, respectively. It is a figure.
As shown in FIGS. 1 and 2, the toner according to the present embodiment has an endothermic peak Tm derived from a crystalline resin in a region of 55 ° C. or higher and 85 ° C. or lower during the temperature raising step, and 55 ° C. or higher and 85 ° C. during the temperature lowering step. It has an endothermic peak Tc derived from a crystalline resin in the region below ° C. When the toner particles contain a release agent, they may have an endothermic peak derived from the release agent, as shown in FIG. 1 at around 90 ° C. In addition, as shown in FIG. 2 at around 75 ° C., it may have an exothermic peak derived from the release agent.
On the other hand, as shown in FIGS. 3 and 4, the conventional toner has an endothermic peak Tm in a region of 55 ° C. or higher and 85 ° C. or lower during the temperature raising step, but a region of 55 ° C. or higher and 85 ° C. or lower during the temperature lowering step. There is no exothermic peak Tc derived from the crystalline resin in. The endothermic peak appearing near 61 ° C. in FIG. 3 is an endothermic peak derived from a crystalline resin compatible with an amorphous resin, and the endothermic peak appearing near 90 ° C. in FIG. 3 and FIG. The exothermic peaks appearing in the vicinity of 85 ° C. in No. 4 are endothermic peaks and exothermic peaks derived from the mold release agent.
As described above, in the conventional toner, the heat generation peak Tc derived from the crystalline resin does not appear in the temperature lowering step, whereas the toner according to the present embodiment has the heat generation peak Tc derived from the crystalline resin in the temperature lowering step.

In the toner containing the crystalline resin, the endothermic peak Tm derived from the crystalline resin that appears in the temperature range in the temperature raising step is considered to be a peak caused by the crystallized portion in the crystalline resin. On the other hand, the exothermic peak Tc derived from the crystalline resin that appears in the temperature range in the temperature lowering step is considered to be a peak caused by the recrystallization of the crystalline resin. That is, the presence of the endothermic peak Tm derived from the crystalline resin and the exothermic peak Tc derived from the crystalline resin in the above temperature range in the temperature raising step under the above conditions and the temperature lowering step under the above conditions records a toner image. It is suggested that the crystalline resin in the toner image recrystallizes at the stage of cooling after fixing on the medium.
The crystallized portion of the crystalline resin has a property of reflecting visible light more easily than the amorphous portion. Therefore, in the toner according to the present embodiment having an endothermic peak Tm and a heat generation peak Tc derived from a crystalline resin in the temperature raising step and the temperature lowering step in the differential scanning calorimetry under the above conditions, the crystals recrystallized in the fixed image. It is considered that the sex resin is present, and as a result, the reflectance of light is increased. As a result, excellent light reflectivity is exhibited in the fixed image, and high concealment property can be obtained particularly in a white image formed by white toner and a bright image such as gold or silver formed by bright toner. ..

・ Differential scanning calorimetry (DSC)
Thermal characteristics such as endothermic peak Tm and heat generation peak Tc of the toner according to the present embodiment are obtained by differential scanning calorimetry (DSC).
The thermal properties of the toner are performed by DSC according to ASTM D3418-99. A differential scanning calorimetry device (manufactured by Shimadzu Corporation, product name: DSC-60A) is used for measurement, the temperature correction of the device detector uses the melting temperature of indium and zinc, and the heat amount is corrected by melting indium. Use heat. An aluminum pan is used as the measurement sample, and an empty pan is set as a control for measurement.
Specifically, 8 mg of toner is set in the sample holder of DSC-60A, the temperature is raised from 0 ° C. to 150 ° C. (heating step) at a heating rate of 10 ° C./min, and the temperature is maintained at 150 ° C. for 5 minutes. To do. Next, the temperature is lowered to −10 ° C./min, cooled to 0 ° C. (temperature lowering step), and held at 0 ° C. for 5 minutes.
The endothermic peak Tm derived from the crystalline resin is obtained from the peak appearing in the region of 55 ° C. or higher and 85 ° C. or lower in the DSC chart obtained in the heating step. The exothermic peak Tc derived from the crystalline resin is obtained from the peak appearing in the region of 55 ° C. or higher and 85 ° C. or lower in the DSC chart obtained in the temperature lowering step. Further, the peak heat amount of the endothermic peak Tm (absolute value of the endothermic amount) and the exothermic peak Tc peak heat amount (absolute value of the endothermic amount) are also calculated from the peaks appearing on the DSC chart.

When the toner according to the present embodiment contains a mold release agent as an optional component, the DSC chart shows the endothermic peak and the heat generation peak caused by the crystalline resin, as well as the endothermic peak caused by the mold release agent and the heat absorbing peak. Fever peaks may appear.
However, whether the peak appearing in the DSC chart is due to the crystalline resin or the release agent can be distinguished by various methods.

The method for identifying whether the peak appearing on the DSC chart in the temperature raising step is due to the crystalline resin or the release agent is as follows, for example.
The two are separated by utilizing the difference in solubility of the crystalline resin and the release agent in the solvent, and the separated components are identified by NMR, mass spectrometry, GPC and the like. As the solvent, for example, tetrahydrofuran, diethyl ether, acetone, methyl ethyl ketone and the like are used. When tetrahydrofuran is used, the crystalline resin tends to be easily dissolved in tetrahydrofuran, and the release agent tends to be difficult to dissolve in tetrahydrofuran. Then, for each of the identified components, a DSC chart in the temperature raising step is obtained, and the endothermic peak appearing in the obtained chart is compared with the DSC chart in the temperature raising step for the toner to raise the temperature of the toner. A method of distinguishing whether the peak appearing on the DSC chart in the process is an endothermic peak caused by the crystalline resin or an endothermic peak caused by the release agent can be mentioned.

The method for identifying the peak appearing on the DSC chart in the temperature lowering step is as follows, for example.
(I) In the DSC chart in the temperature raising step, the endothermic peak caused by the crystalline resin appears at a temperature 8 ° C. or more lower than the endothermic peak caused by the release agent.
In this case, the temperature at the peak of the peak between the endothermic peak caused by the crystalline resin and the endothermic peak caused by the release agent in the DSC chart in the temperature raising step for the toner is determined. Next, the temperature of the toner is raised from 0 ° C. to the temperature of the peak of the peak, and the toner is held at the temperature of the top of the peak for 5 minutes. Next, the temperature is lowered to 0 ° C. at a temperature lowering rate of −10 ° C./min, and a DSC chart at this time is obtained. By heating to the temperature at the top of the peak of the DSC chart in the temperature raising step, the crystalline resin contained in the toner is dissolved, but the release agent is not dissolved. By lowering the temperature in this state, an exothermic peak due to the crystalline resin appears on the DSC chart. From this chart, it is possible to identify the exothermic peak caused by the crystalline resin.
(Ii) In the DSC chart in the temperature raising step, the difference between the endothermic peak caused by the crystalline resin and the endothermic peak caused by the release agent is less than 8 ° C.
The exothermic peak when the temperature difference between the endothermic peaks is close can be identified by the following means.
In order to compare the endothermic peak calories of the release agent and the crystalline resin in the toner, the release agent is separated by utilizing the difference in solubility of the release agent and the binder resin in the solvent. Next, after separating the release agent, DSC measurement is performed on the toner components other than the release agent, and the endothermic peak calorific value of the crystalline resin is measured. At this time, the toner components other than the release agent are heated at a temperature 5 ° C. to 10 ° C. higher than the glass transition temperature (Tg) of the toner for 1 hour, and then the measurement is performed. Further, when measuring the endothermic peak calorific value of the crystalline resin, the separation is performed without changing the ratio of the toner components other than the mold release agent in the measurement, or the calculation is performed according to the composition ratio.
Then, the endothermic peak heat of the entire toner is compared with the endothermic peak heat of the crystalline resin obtained as described above, and the endothermic peak heat of the toner due to the mold release agent is estimated.
Next, the DSC measurement is performed and the heat generation peak calorific value is confirmed by the DSC chart in the toner temperature lowering step. Here, when the exothermic peak is divided into a plurality of parts, the endothermic peak calorific value and the exothermic peak calorific value can be compared, and those having a similar calorific value can be identified as a crystalline resin or a mold release agent.
When the exothermic peaks overlap, it can be identified that the exothermic peaks of the release agent and the crystalline resin are the same. Further, since the heat generation peak heat quantity of the mold release agent can be measured by separating the mold release agent and measuring the heat absorption peak heat quantity by the method described above, even if the heat generation peaks overlap, the mold release agent By subtracting the heat generation peak heat quantity, the heat generation peak heat quantity of the crystalline resin can be estimated.

・ Peak calorific value Qc of exothermic peak Tc appearing in the temperature lowering process
The peak calorific value (absolute value of calorific value) Qc of the exothermic peak Tc ^{is preferably 5 × 10 -3} J / g or more and 10 J / g or less, and 1 × 10 ^-2 J / g or more and 10 J / g or less. More preferably, it is more preferably 0.1 J / g or more and 10 J / g or less.
The fact that the peak calorific value Qc of the exothermic peak is 5 × 10 ^-3 J / g or more suggests that there are many crystallized (recrystallized) portions of the crystalline resin in the fixed image. Light reflectivity is more likely to increase.
On the other hand, when the peak calorific value Qc of the exothermic peak Tc is 10 J / g or less, the advantage of improving the bending strength can be obtained, and particularly in the case of an application using a film as a recording medium, the advantage of improving the bending strength is great.

-Peak calorific value Qm of the endothermic peak Tm that appears in the temperature raising process
The peak calorific value (absolute value of the endothermic amount) Qm of the endothermic peak Tm appearing in the temperature raising step is preferably 0.5 J / g or more and 30 J / g or less, and more preferably 5 J / g or more and 30 J / g or less. It is preferable that it is 7 J / g or more and 30 J / g or less.
The fact that the peak calorific value Qm of the endothermic peak is 0.5 J / g or more suggests that there are many crystalline resins that can be crystallized, which makes it easier to enhance the light reflectivity.
On the other hand, when the peak calorific value Qm of the endothermic peak is 30 J / g or less, the advantage of improving the bending strength can be obtained, and particularly in the case of an application using a film as a recording medium, the advantage of improving the bending strength is great.

-Ratio of peak calorific value Qc and peak calorific value Qc The ratio of peak calorific value Qc of exothermic peak Tc to peak calorific value Qm of heat absorption peak Tm [Qc / Qm] is ^{preferably 5 × 10 -4} or more and 0.8 or less. It is more preferably 1 × 10 ^-3 or more and 0.8 or less, and further preferably 1 × 10 ^-2 or more and 0.8 or less.
The fact that the ratio [Qc / Qm] is 5 × 10 ^-4 or more suggests that many of the crystalline resins contained in the toner are recrystallized, and the light reflectivity is high. It becomes easier to increase.
On the other hand, when the ratio [Qc / Qm] is 0.8 or less, the advantage of improving the bending strength can be obtained, and particularly in the case of using a film as a recording medium, the advantage of improving the bending strength is great.

-Ratio of peak calorific value Qc and crystalline resin content The ratio of the peak calorific value Qc (J / g) of the exothermic peak Tc to the crystalline resin content Cr (mass%) in the toner particles [Qc / Cr] Is preferably 5 × 10 ^-4 or more and 1.0 or less, more preferably 1 × 10 ^-3 or more and 1.0 or less, and further preferably 1 × 10 ^-2 or more and 1.0 or less. preferable.
The fact that the ratio [Qc / Cr] is 5 × 10 ^-4 or more suggests that many of the crystalline resins contained in the toner are recrystallized, and the light reflectivity is high. It becomes easier to increase.
On the other hand, when the ratio [Qc / Cr] is 1.0 or less, the advantage of improving the bending strength can be obtained, and particularly in the case of using a film as a recording medium, the advantage of improving the bending strength is large.

-Temperature of the exothermic peak Tc appearing in the temperature lowering process and the endothermic peak Tm appearing in the temperature raising process The exothermic peak Tc appearing in the temperature lowering process appears in the range of 55 ° C. or higher and 85 ° C. Is more preferable, and it is more preferably 60 ° C. or higher and 85 ° C. or lower, and further preferably 62 ° C. or higher and 85 ° C. or lower.
When the heat generation peak Tc is in the above range, the low temperature fixability is further improved.

The endothermic peak Tm that appears in the temperature raising step appears in the range of 55 ° C. or higher and 85 ° C. or lower, but more preferably 58 ° C. or higher and 85 ° C. or lower, more preferably 60 ° C. or higher and 85 ° C. or lower, and 62 ° C. It is more preferably 85 ° C. or lower.
When the endothermic peak Tm is in the above range, the low temperature fixability is further improved when the amorphous resin is contained. It is considered that the glass dislocation of the amorphous resin to the rubber state is more likely to occur in preference to the melting of the crystalline resin, and the entire toner is likely to be softened at a low temperature.

-Achievement method Here, a method for realizing the toner according to the present embodiment in which the heat generation peak Tc appears in the temperature range of the temperature lowering step in the differential scanning calorimetry under the above conditions will be described. The achievement method is not particularly limited, and examples thereof include the following methods.

(1) Method for adjusting the domain of the crystalline resin A method of forming a domain (aggregate) of the crystalline resin in the toner particles and increasing the domain diameter thereof can be mentioned. The method is not particularly limited, and examples thereof include the following methods.
For example, in the case of producing toner particles by the aggregation and coalescence method described later, the crystalline resin particles are aggregated in advance by performing aggregation (pre-aggregation) using a crystalline resin particle dispersion liquid, and then colored. An agent (at least one pigment selected from an inorganic pigment and a metal pigment) particle dispersion liquid, and if necessary, an amorphous resin particle dispersion liquid, a release agent particle dispersion liquid, and the like are added to further agglomerate to form agglomerated particles. This includes a method of producing toner particles. The domain of the crystalline resin is formed by the pre-aggregation, and the domain diameter can be increased by adjusting the degree of the pre-aggregation.
Further, in the case of producing the toner particles by the dissolution / suspension method or the kneading / pulverizing method described later, a method of providing a heating step (post-annealing step) after forming the toner particles can be mentioned. The domain diameter can be increased by forming a domain of the crystalline resin by the post-annealing step and adjusting the degree of heating thereof.

(2) Method of Containing Inorganic Pigment and Metal Pigment Further, as a method of realizing the toner according to the present embodiment in which the exothermic peak Tc derived from the crystalline resin appears in the temperature lowering step, the colorant is selected from the inorganic pigment and the metal pigment. There is a method using at least one kind of pigment to be used. Inorganic pigments and metal pigments tend to have a lower specific heat and a higher thermal conductivity than, for example, conventionally used binder resins. By containing at least one of the inorganic pigment and the metal pigment having low specific heat and high thermal conductivity, the inorganic pigment or the metal pigment is preferentially cooled at the time of cooling after the fixing step as compared with the case where the pigment is not contained. Therefore, it is considered that the rate of decrease in the temperature of the crystalline resin becomes slow and the recrystallization of the crystalline resin is easily promoted.

The above pigments (inorganic pigments, metal pigments) are preferably aggregated. Further, when the crystalline resin forms a domain in the toner particles, it is preferable that the crystalline resin is contained in this domain. By including the pigment having a high specific heat capacity in the domain of the crystalline resin, the rate of decrease in the temperature of the crystalline resin becomes slower during cooling after the fixing step, and the recrystallization of the crystalline resin is further promoted. It will be easier.

Here, the ratio of the pigment contained in the domain of the crystalline resin is preferably 5% by number or more, preferably 10% by number or more, based on the total amount of the above pigments (inorganic pigment, metal pigment) contained in the toner particles. More preferably, 15% by number or more is further preferable.
When the ratio of the pigment contained in the domain to the total amount of the pigment contained in the toner particles is 5% by number or more, the rate of decrease in the temperature of the crystalline resin becomes slow during cooling after the fixing step. The recrystallization of the crystalline resin is easily promoted.

The method of incorporating the pigment (inorganic pigment, metal pigment) in the domain of the crystalline resin is not particularly limited, but is, for example, in the case of producing toner particles by the aggregation and coalescence method described later. If there is, at the time of the pre-aggregation (aggregation is performed in advance using the crystalline resin particle dispersion to aggregate the crystalline resin particles), the pigment particles are dispersed in addition to the crystalline resin particle dispersion. A liquid is added to form a pre-aggregate of crystalline resin particles and a pigment, and if necessary, an amorphous resin particle dispersion, a release agent particle dispersion, etc. are added to further aggregate to form agglomerated particles. By doing so, a method of producing toner particles can be mentioned. By including the pigment in addition to the crystalline resin at the time of the pre-aggregation, the pigment is contained in the domain.

Hereinafter, the details of the toner according to this embodiment will be described.

The toner according to the present embodiment is composed of toner particles and, if necessary, an external additive.

(Toner particles)
The toner particles are composed of, for example, a binder resin, a colorant containing at least one pigment selected from an inorganic pigment and a metal pigment, and, if necessary, a mold release agent and other additives. Toner.

-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, Methacrylic acid, 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 monomers 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.
In the present embodiment, at least a crystalline resin is used as the binder resin, and it is preferable to use an amorphous resin in combination.

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 is 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.). / Min) indicates that the half-value width of the endothermic peak 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 (eg, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (eg, 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 70 ° 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 5000 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 2000 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 using a Tosoh GPC / HLC-8120GPC as a measuring device, a Tosoh column / TSKgel SuperHM-M (15 cm), and a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results 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, it can be obtained by a method in which the polymerization temperature is 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 include a polyester resin in which a functional group such as an isocyanate group that reacts with an acid group or a hydroxyl group is introduced at the terminal, and a resin in which the terminal is modified by reacting with an active hydrogen compound.

As the modified polyester resin, a urea-modified polyester resin is particularly preferable. The content of the urea-modified polyester resin is preferably 2% by mass or more and 25% by mass or less, and more preferably 5% by mass or more and 20% by mass or less with respect to the total binder resin.
The urea-modified polyester resin is often one of the amorphous resins, although it depends on the type of monomer used, the blending amount, and the like.

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 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 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 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 each 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.

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.) ); And aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like.
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.
Blocking these amino groups includes 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 stops at least one of the cross-linking reaction and the extension reaction (hereinafter, also referred to as “cross-linking / extension 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.

The glass transition temperature of the urea-modified polyester resin is preferably 40 ° C. or higher and 80 ° C. or lower, and more preferably 45 ° C. or higher and 65 ° C. or lower. The number average molecular weight is preferably 2500 or more and 50,000 or less, and more preferably 2500 or more and 30,000 or less. The weight average molecular weight is preferably 10,000 or more and 500,000 or less, and more preferably 30,000 or more and 100,000 or less.

-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-tetradecanedicarboxylic 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 55 ° C. or higher and 85 ° C. or lower, more preferably 55 ° C. or higher and 80 ° C. or lower, and further preferably 60 ° C. or higher and 80 ° 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 crystalline polyester resin can be obtained by a well-known manufacturing method, like the amorphous polyester resin, for example.

The content of the binder resin is, for example, preferably 15% by mass or more and 95% by mass or less, more preferably 20% by mass or more and 90% by mass or less, and 20% by mass or more and 85% by mass or less with respect to the entire toner particles. More preferred.

-Colorant-
The toner according to the present embodiment contains at least one pigment selected from an inorganic pigment and a metal pigment as a colorant.

The components of the inorganic pigment used in this embodiment include titanium dioxide (titania), silica, alumina, calcium carbonate, aluminum hydroxide, satin white, talc, calcium sulfate, magnesium oxide, magnesium carbonate, white carbon, kaolin, and aluminosilicate. Examples thereof include silicate, sericite, bentonite, smectite and the like. The inorganic pigment used in this embodiment is preferably titanium oxide particles when the toner according to this embodiment functions as a so-called white toner. Further, by using the (rutile type) titanium oxide particles, it becomes easier to increase the light reflectance in the formed image.

Examples of the components of the metal pigment used in the present embodiment include metal particles such as aluminum, brass, bronze, nickel, stainless steel, and zinc. The metal pigment used in the present embodiment is preferably aluminum particles when the toner according to the present embodiment functions as a so-called brilliant toner. Further, by using the aluminum particles, it becomes easier to increase the light reflectance in the formed image.

The toner according to the present embodiment may be used in combination with other colorants other than the inorganic pigment and the metal pigment. Examples of other colorants include organic pigments and organic dyes.
Other colorants include, for example, carbon black, chrome yellow, hanza 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 Carmine 6B, Dupont Oil Red, Pyrazolon Red, Resole Red, Rhodamin 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 Various pigments such as green and malakite green oxalate, or aclysine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, Examples thereof include dyes such as aniline black, polymethine, triphenylmethane, diphenylmethane, and thiazole.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. Further, a plurality of kinds of colorants may be used in combination.

The content of the colorant is, for example, preferably 1% by mass or more and 70% by mass or less, more preferably 20% by mass or more and 70% by mass or less, and further preferably 35% by mass or more and 70% by mass or less with respect to the entire toner particles. preferable.

-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 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° 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, more preferably 3% by mass or more and 15% by mass or less, and 3% by mass or more and 10% by mass or less with respect to the entire toner particles. More preferred.

-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 may be toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) covering 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.

The volume average particle size (D50v) of the toner particles is preferably 2 μm or more and 15 μm or less, and more preferably 4 μm or more and 10 μm or less.

The various average particle sizes of the toner particles and various particle size distribution indexes were measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte was measured using ISOTON-II (manufactured by Beckman Coulter). Toner.
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm or more and 60 μm or less is obtained by using a Coulter Multisizer II with an aperture of 100 μm. Measure. The number of particles to be sampled is 50,000.
Cumulative distribution of volume and number is drawn from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the cumulative 16% particle size is volume particle size D16v and number particle size. The particle size having D16p and a cumulative 50% is defined as the volume average particle size D50v and the cumulative number average particle size D50p, and the particle size having a cumulative number of 84% is defined as the volume particle size D84v and the number particle size D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 , and the number particle size distribution index (GSDp) is calculated as ^{(D84p / D16p) 1/2.}

The average circularity of the toner particles is preferably 0.92 or more and 1.00 or less, and more preferably 0.95 or more and 0.98 or less.

The average circularity of the toner particles is obtained by (perimeter equivalent to a circle) / (perimeter) [(perimeter of a circle having the same projected area as the particle image) / (perimeter of the projected particle image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Cysmex) that captures a particle image as a still image by sucking and collecting toner particles to be measured, forming a flat flow, and instantly causing strobe light emission to analyze the particle image. Obtained by FPIA-2100) manufactured by the company. Then, the number of samples for obtaining the average circularity is set to 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed. ..

(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 10 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 is preferably 0.01% by mass or more and 5% by mass or less, and 0.01% by mass or more and 2.0% by mass or less, with respect to the toner particles, for example. More preferred. Moreover, it is preferable that all kinds of external additives are 0.01% by mass or more and 10% 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.

[Aggregation union 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 (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. Toner particles are manufactured through a step of fusing and coalescing agglomerated particles to form toner particles (fusing and coalescing step).

From the viewpoint of forming a crystalline resin domain (aggregate) in the toner particles and increasing the domain diameter thereof, the crystalline resin in which the crystalline resin particles are dispersed is prior to the aggregated particle forming step. It is preferable to provide a pre-aggregation step in which the crystalline resin particles are aggregated by performing agglomeration (pre-aggregation) in advance using the particle dispersion liquid. Then, after this pre-aggregation step, an amorphous resin particle dispersion, a colorant particle dispersion, a release agent particle dispersion, or the like is added to the dispersion containing the pre-aggregate to perform the aggregation particle formation step. Is preferable.
At least one pigment selected from an inorganic pigment and a metal pigment is used as the colorant, and it is preferable that the pigment (inorganic pigment, metal pigment) is aggregated to the extent that the light reflection efficiency is not lowered. Therefore, in the pre-aggregation step, it is preferable to form a pre-aggregate of at least one pigment selected from inorganic pigments and metal pigments.

The details of each step will be described below.
In the following description, a method of obtaining toner particles containing a release agent will be described, but the release agent is used as needed. Of course, other additives other than the release agent 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 homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of the resin particles, the resin particles may be dispersed in the resin particle dispersion liquid by using, 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 0.05 μm or more and 0.8 μm or less, and further preferably 0.05 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 cumulatively 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 40% by mass or less.

In addition, in the same manner as the resin particle dispersion liquid, for example, a colorant particle dispersion liquid and a release agent particle dispersion liquid 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 liquid, the colorant particles dispersed in the colorant particle dispersion liquid and the release agent particle dispersion liquid are used. The same applies to the disperse of the release agent particles.

-Agglomerated particle formation process-
Next, the colorant particle dispersion liquid and the release agent particle dispersion liquid are mixed together with the resin particle dispersion liquid.
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 resin particles are heated to a temperature equal to or lower than the glass transition temperature (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. To form aggregated particles.
In the agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear 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.

It is preferable to provide a pre-aggregation step before forming the agglomerated particles containing the resin particles, the colorant particles, and the release agent particles.
A pre-aggregation step of pre-aggregating (pre-aggregating) using a dispersion of at least one pigment selected from an inorganic pigment and a metal pigment to form a pre-aggregation of pigment particles is provided, and after this pre-aggregation step, pre-aggregation is performed. It is preferable to add an amorphous resin particle dispersion, a crystalline resin particle dispersion, a mold release agent particle dispersion, or the like to the pigment dispersion containing the agglomerates to perform the agglomerate particle forming step.
Further, in the pre-aggregation step, a crystalline resin dispersion is added in addition to a dispersion of at least one pigment selected from inorganic pigments and metal pigments, and the mixture is selected from crystalline resin particles and inorganic pigments and metal pigments. A pre-aggregate with at least one kind of pigment is formed, and then an amorphous resin particle dispersion, a release agent particle dispersion, or the like is added to the dispersion containing the pre-aggregate to carry out the aggregate particle formation step. Is even more preferable.

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.
Further, from the viewpoint of arranging the crystalline resin in the vicinity of at least one pigment selected from the inorganic pigment and the metal pigment to promote recrystallization, the heating temperature in the fusion / union step is set to the melting temperature of the crystalline resin ±. It may be 10 ° C.

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 a step 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-flow 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.

[Dissolution Suspension Method]
Next, a method for forming toner particles by the dissolution / suspension method will be described.
For example, in the dissolution / suspension method, a liquid in which raw materials (binding resin, colorant, etc.) constituting toner particles are dissolved or dispersed in an organic solvent in which the binding resin can be dissolved is contained as a particle dispersant. This is a method obtained by granulating toner particles by dispersing the particles in an aqueous solvent and then removing the organic solvent.

Among these, toner particles containing a urea-modified polyester resin as a binder resin may be obtained by the following dissolution / suspension method. In the following description of the dissolution / suspension method, a method of obtaining toner particles containing a crystalline resin, an unmodified polyester resin, and a urea-modified polyester resin as a binder resin will be described, but the toner particles are crystalline as a binder resin. Only the resin and the urea-modified polyester resin may be contained.

-Oil phase liquid preparation process-
A toner particle material containing a crystalline resin, an unmodified polyester resin, a polyester prepolymer having an isocyanate group, an amine compound, at least one pigment selected from inorganic pigments and metal pigments, and a mold release agent is dissolved or dispersed in an organic solvent. Prepare the prepared oil phase liquid (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 at once, and 2) kneading the toner material in advance and then dissolving or dispersing this kneaded product in an organic solvent. 3) At least one selected from inorganic pigments and metal pigments in this organic solvent after dissolving a crystalline resin, an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound in an organic solvent. A method for preparing by dispersing a pigment and a mold release agent, 4) At least one pigment selected from an inorganic pigment and a metal pigment, and a mold release agent are dispersed in an organic solvent, and then crystals are dissolved in this organic solvent. Method of dissolving and preparing sex resin, unmodified polyester resin, polyester prepolymer having isocyanate group, and amine compound 5) Toner particle material other than polyester prepolymer having isocyanate group and amine compound (crystalline resin, not yet A modified polyester resin, at least one pigment selected from inorganic pigments and metal pigments, and a mold release agent) are dissolved or dispersed in an organic solvent, and then a polyester prepolymer having an isocyanate group and an amine compound are added to the organic solvent. Method of Dissolving and Preparing, 6) Toner Particle Material Other Than Polyester Prepolymer or Amine Compound Having Isocyanate Group (Crystalous Resin, Unmodified Polyester Resin, At least One Pigment Selected from Inorganic Pigment and Metallic Pigment, and Release A method of preparing by dissolving or dispersing the mold) in an organic solvent and then dissolving a polyester prepolymer or an amine compound having an isocyanate group in the organic solvent can be mentioned. 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. These organic solvents preferably 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 solvent removing step described later.
Here, the reaction conditions are selected based on the reactivity between the isocyanate group structure of the polyester prepolymer and the amine compound. As an example, the reaction time is preferably 10 minutes 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., and preferably 40 ° C. or higher and 98 ° C. or lower. If necessary, a known catalyst (dibutyltin laurate, dioctyltin laurate, etc.) may be used to produce the urea-modified polyester resin. That is, the catalyst may be added to the oil phase liquid or the 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 hydrophilic inorganic particle dispersants. 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. In addition, surface treatment may be performed if necessary.

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 composed of alkali metal, alkaline earth metal, ammonia, 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. , Salts neutralized with ammonia, amines and the like (alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts and the like) can also be mentioned. 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.

Further, in the present embodiment, from the viewpoint of arranging the crystalline resin in the vicinity of at least one pigment selected from the inorganic pigment and the metal pigment to promote recrystallization, a heating step (post-annealing) is performed on the particles that have undergone the solvent removal step. Step) is preferably provided. By adjusting the degree of heating (heating temperature and heating time) in this post-annealing step, a crystalline resin can be arranged in the vicinity of at least one pigment selected from inorganic pigments and metal pigments to promote recrystallization. it can.
The heating temperature is preferably in the range of ± 10 ° C. for the melting temperature of the crystalline resin, and more preferably in the range of ± 5 ° C. for the melting temperature of the crystalline resin. The longer the heating time is, the more preferable it is, but when heating in the range of the melting temperature of other materials such as a mold release agent of ± 10 ° C., the range is preferably 1 minute or more and 300 minutes or less, and 30 minutes or more and 120 minutes. The following range is more preferable.

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 obtained as dried toner particles through a known washing step, solid-liquid separation step, and drying step.
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-flow 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.

[Kneading and crushing method]
Next, a method of forming toner particles by the kneading and pulverizing method will be described.
In the kneading and pulverizing method, after mixing each material such as a colorant and a binder resin, the above materials are melt-kneaded using a kneader, an extruder, etc., and the obtained melt-kneaded product is roughly pulverized and then jet milled. This is a method of obtaining toner particles having a target particle size by crushing them with a wind classifier.
More specifically, the kneading and crushing method is divided into a kneading step of kneading a toner forming material containing at least one pigment selected from an inorganic pigment and a metal pigment and a binder resin, and a crushing step of crushing the kneaded product. Be done. If necessary, it may have other steps such as a cooling step of cooling the kneaded product formed by the kneading step.

Each step related to the kneading and crushing method will be described in detail.
-Kneading process-
The kneading step kneads a toner-forming material containing at least one pigment selected from inorganic pigments and metal pigments and a binder resin.
In the kneading step, it is desirable to add 0.5 parts by mass or more and 5 parts by mass or less of an aqueous medium (for example, water such as distilled water or ion-exchanged water, alcohols, etc.) to 100 parts by mass of the toner forming material. ..

Examples of the kneading machine used in the kneading step include a single-screw extruder and a twin-screw extruder. Hereinafter, as an example of the kneading machine, a kneading machine having a feed screw portion and two kneading portions will be described with reference to the drawings, but the present invention is not limited to this.

FIG. 5 is a diagram illustrating a screw state with respect to an example of a screw extruder used in a kneading step in the toner manufacturing method according to the present embodiment.
The screw extruder 11 adds an aqueous medium to the barrel 12 provided with a screw (not shown), the injection port 14 for injecting the toner forming material which is the raw material of the toner into the barrel 12, and the toner forming material in the barrel 12. It is composed of a liquid addition port 16 for discharging the kneaded material formed by kneading the toner forming material in the barrel 12 and a discharge port 18 for discharging the kneaded material.

The barrel 12 has a feed screw portion SA that transports the toner forming material injected from the injection port 14 to the kneading portion NA in order from the side closest to the injection port 14, and the toner forming material is melt-kneaded by the first kneading step. Knee to form a kneaded product by melting and kneading the feed screw portion SB and the toner forming material for transporting the toner forming material melt-kneaded in the kneading portion NA and the kneading portion NA to the kneading portion NB by the second kneading step. It is divided into a ding portion NB and a feed screw portion SC that transports the formed kneaded material to the discharge port 18.

Further, inside the barrel 12, different temperature control means (not shown) are provided for each block. That is, the temperature may be controlled differently from the block 12A to the block 12J. FIG. 5 shows a state in which the temperatures of the blocks 12A and 12B are controlled to t0 ° C., the temperatures of the blocks 12C to 12E are controlled to t1 ° C., and the temperatures of the blocks 12F to 12J are controlled to t2 ° C. There is. Therefore, the toner forming material of the kneading portion NA is heated to t1 ° C., and the toner forming material of the kneading portion NB is heated to t2 ° C.

When a toner forming material containing at least one pigment selected from a binder resin, an inorganic pigment and a metal pigment, and if necessary, a mold release agent and the like is supplied from the injection port 14 to the barrel 12, the feed screw portion SA knees. The toner forming material is sent to the ding portion NA. At this time, since the temperature of the block 12C is set to t1 ° C., the toner forming material is sent to the kneading section NA in a state of being heated and changed to a molten state. Since the temperatures of the blocks 12D and 12E are also set to t1 ° C., the toner forming material is melt-kneaded at the temperature of t1 ° C. in the kneading portion NA. The binder resin and the mold release agent are in a molten state at the kneading portion NA and are sheared by the screw.

Next, the toner forming material that has undergone kneading in the kneading portion NA is sent to the kneading portion NB by the feed screw portion SB.
Then, in the feed screw portion SB, the water-based medium is added to the toner-forming material by injecting the water-based medium into the barrel 12 from the liquid addition port 16. Further, FIG. 5 shows a form in which the water-based medium is injected into the feed screw portion SB, but the present invention is not limited to this, and the water-based medium may be injected into the kneading portion NB, and the feed screw portion SB and the kneading portion NB may be injected. An aqueous medium may be injected in both. That is, the position and the injection location for injecting the aqueous medium are selected as necessary.

As described above, when the water-based medium is injected into the barrel 12 from the liquid addition port 16, the toner-forming material in the barrel 12 and the water-based medium are mixed, and the toner-forming material is cooled by the latent heat of vaporization of the water-based medium. The temperature of the toner forming material is maintained.
Finally, the kneaded product formed by melt-kneading by the kneading portion NB is transported to the discharge port 18 by the feed screw portion SC and discharged from the discharge port 18.
As described above, the kneading step using the screw extruder 11 shown in FIG. 5 is performed.

-Cooling process-
The cooling step is a step of cooling the kneaded product formed in the kneading step, and in the cooling step, the temperature of the kneaded product at the end of the kneading step is cooled to 40 ° C. or lower at an average temperature lowering rate of 4 ° C./sec or more. It is preferable to do so. When the cooling rate of the kneaded product is slow, the mixture finely dispersed in the binder resin (at least one pigment selected from inorganic pigments and metal pigments and, if necessary, added to the toner particles in the kneading process) is added. The mixture with an internal additive such as a release agent) may be recrystallized and the dispersion diameter may be increased. On the other hand, quenching at the above average temperature lowering rate is preferable because the dispersed state immediately after the completion of the kneading step is maintained as it is. The average temperature lowering rate is the average value of the rate at which the temperature of the kneaded product is lowered from the temperature of the kneaded product (for example, t2 ° C. when the screw extruder 11 in FIG. 5 is used) to 40 ° C. at the end of the kneading step.
Specific examples of the cooling method in the cooling step include a method using a rolling roll in which cold water or brine is circulated, a sandwiching type cooling belt, and the like. When cooling is performed by the above method, the cooling rate is determined by the speed of the rolling roll, the flow rate of brine, the supply amount of the kneaded product, the slab thickness at the time of rolling the kneaded product, and the like. The slab thickness is preferably as thin as 1 mm or more and 3 mm or less.

-Crushing process-
The kneaded product cooled by the cooling step is crushed by the crushing step to form particles. In the crushing step, for example, a mechanical crusher, a jet crusher, or the like is used.

-Post-annealing process-
Further, in the present embodiment, from the viewpoint of arranging the crystalline resin in the vicinity of at least one pigment selected from the inorganic pigment and the metal pigment to promote recrystallization, the particles (or the classification step described later) are subjected to the pulverization step. It is preferable to provide a heating step (post-annealing step) on the aged particles. By adjusting the degree of heating (heating temperature and heating time) in this post-annealing step, a crystalline resin can be arranged in the vicinity of at least one pigment selected from inorganic pigments and metal pigments to promote recrystallization. it can.
The heating temperature is preferably in the range of ± 10 ° C. for the melting temperature of the crystalline resin, and more preferably in the range of ± 5 ° C. for the melting temperature of the crystalline resin. The longer the heating time is, the more preferable it is, but when heating in the range of the melting temperature of other materials such as a mold release agent of ± 10 ° C., the range is preferably 1 minute or more and 300 minutes or less, and 30 minutes or more and 120 minutes. The following range is more preferable.

-Classification process-
The particles obtained in the pulverization step may be classified by a classification step in order to obtain toner particles having a volume average particle size in a target range, if necessary. In the classification process, conventionally used centrifugal classifiers, inertial classifiers, etc. are used, and fine powder (particles smaller than the target particle size) and coarse powder (particle size in the target range) are used. Larger particles) are removed.

-External process-
An external agent such as inorganic particles typified by silica, titania, or aluminum oxide may be added and adhered to the obtained toner particles for the purpose of adjusting charge, imparting fluidity, imparting charge exchange property, and the like. These are performed by, for example, a V-type blender, a Henschel mixer, a Ladyge mixer, or the like, and may be attached in stages.

-Sieve process-
If necessary, a sieving step may be provided after the external addition step. Specific examples of the sieving method include a gyro shifter, a vibration sieving machine, and a wind sieving machine. By sieving, coarse powder of the external additive is removed, and streaks on the photoconductor and spilled stains in the apparatus are suppressed.

<Static charge image developer>
The electrostatic charge image developer according to the present embodiment contains at least the toner according to the present embodiment.
The electrostatic charge image developer according to the present embodiment may be a one-component developer containing only the toner according to the present embodiment, or a two-component developer mixed with the toner and a carrier.

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.

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 and the like 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 coating layer forming solution is sprayed, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and a solvent is removed.

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 5: 100 to 25: 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. The toner image transferred to the surface of the recording medium is provided with a transfer means for transferring the toner image to the surface of the recording medium, and a fixing means for fixing the toner image transferred to the surface of the recording medium by heating. 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) is carried out, which comprises a fixing step of fixing a toner image transferred to the surface of a recording medium by heating.

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 description thereof will be omitted for the others.

FIG. 6 is a schematic configuration diagram showing an example of the image forming apparatus according to the present embodiment. The image forming apparatus according to the present embodiment relates to a tandem type configuration in which a plurality of photoconductors as image holders, that is, a plurality of image forming units (image forming means) are provided.

In this embodiment, at least one of an inorganic pigment and a metal pigment is used as the colorant. Furthermore, it is preferable to use titanium oxide particles as the inorganic pigment and use the toner according to the present embodiment as a so-called white toner. Further, it is preferable to use aluminum particles as the metal pigment and use the toner according to the present embodiment as a so-called brilliant toner.
Therefore, in the following description, in addition to the yellow, magenta, cyan, and black toners, a case where a white toner or a brilliant toner (for example, silver toner) is used as the toner according to the present embodiment will be described as an example.

As shown in FIG. 6, the image forming apparatus according to the present embodiment includes four image forming units 50Y, 50M, 50C, and 50K for forming toner images of yellow, magenta, cyan, and black, respectively, and a white toner image. And image forming units 50B forming at least one image of the brilliant toner image are arranged in parallel (in tandem) at intervals. The image forming units are arranged in the order of the image forming units 50Y, 50M, 50C, and 50K from the upstream side in the rotation direction of the intermediate transfer belt 33, and the image forming unit 50B is in front of the image forming unit 50Y or an image. It is located at least one behind the forming unit 50K. In the following description, the case where the image forming unit 50B is arranged only behind the image forming unit 50K will be described as an example, but the image forming unit 50B may be arranged in front of the image forming unit 50Y, and the image forming unit 50B may be arranged. It is also possible to arrange the image forming unit 50B both in front of the unit 50Y and behind the image forming unit 50K.
Here, since each image forming unit 50Y, 50M, 50C, 50K, 50B has the same configuration except for the color of the toner in the stored developer, here, image forming for forming a yellow image is performed. The unit 50Y will be described as a representative. In addition, a reference code with magenta (M), cyan (C), black (K), white or brilliant (B) is attached to the same portion as the image forming unit 50Y instead of yellow (Y). Therefore, the description of each image forming unit 50M, 50C, 50K, 50B will be omitted.

The yellow image forming unit 50Y includes a photoconductor 21Y as an image holder, and the photoconductor 21Y is rotationally driven along the direction of arrow A shown by a driving means (not shown) at a predetermined process speed. It has become so. As the photoconductor 21Y, for example, an organic photoconductor having sensitivity in the infrared region is used.

A charging roll (charging means) 28Y is provided on the upper portion of the photoconductor 21Y, and a predetermined voltage is applied to the charging roll 28Y by a power source (not shown), and the surface of the photoconductor 21Y is predetermined. It is charged to the potential.

Around the photoconductor 21Y, an exposure device (static charge image forming means) 19Y that exposes the surface of the photoconductor 21Y to form a static charge image is arranged on the downstream side of the photoconductor 21Y in the rotation direction of the charging roll 28Y. Has been done. Here, as the exposure apparatus 19Y, an LED array that can be miniaturized is used due to space limitations, but the present invention is not limited to this, and an electrostatic charge image forming means using another laser beam or the like is used. But of course there is no problem.

Further, around the photoconductor 21Y, a developing device (development means) 20Y provided with a developer holder for holding a yellow color developer is arranged on the downstream side of the photoconductor 21Y in the rotation direction with respect to the exposure device 19Y. The electrostatic charge image formed on the surface of the photoconductor 21Y is visualized with a yellow toner to form a toner image on the surface of the photoconductor 21Y.

Below the photoconductor 21Y, an intermediate transfer belt (primary transfer means) 33 for primary transfer of the toner image formed on the surface of the photoconductor 21Y extends below the five photoconductors 21Y, 21M, 21C, 21K, and 21B. It is arranged like this. The intermediate transfer belt 33 is pressed against the surface of the photoconductor 21Y by the primary transfer roll 17Y. Further, the intermediate transfer belt 33 is stretched by three rolls of a drive roll 22, a support roll 23, and a bias roll 24, and is rotated in the arrow B direction at a movement speed equal to the process speed of the photoconductor 21Y. It has become. A yellow toner image is first-order transferred to the surface of the intermediate transfer belt 33, and magenta, cyan, black, and white or brilliant color toner images are sequentially first-transferred and laminated.

Further, around the photoconductor 21Y, the toner remaining on the surface of the photoconductor 21Y and the retransferred toner are cleaned downstream of the primary transfer roll 17Y in the rotation direction (arrow A direction) of the photoconductor 21Y. A cleaning device 15Y is arranged. The cleaning blade in the cleaning device 15Y is attached to the surface of the photoconductor 21Y so as to be in pressure contact with the surface in the counter direction.

A secondary transfer roll (secondary transfer means) 34 is pressed against the bias roll 24 on which the intermediate transfer belt 33 is stretched via the intermediate transfer belt 33. The toner image primaryly transferred and laminated on the surface of the intermediate transfer belt 33 is formed on the surface of the recording paper (recording medium) P fed from a paper cassette (not shown) at the pressure contact portion between the bias roll 24 and the secondary transfer roll 34. It is electrostatically transferred. At this time, since the toner image transferred and laminated on the intermediate transfer belt 33 has the white toner image or the brilliant toner (for example, silver toner) image on the top (top layer), it is transferred to the surface of the recording paper P. In the resulting toner image, the white toner image or the brilliant toner image is at the bottom (bottom layer).

Further, downstream of the secondary transfer roll 34, a fixing device (fixing means) for fixing the toner image multiplex-transferred on the recording paper P to the surface of the recording paper P by heat and pressure to form a permanent image. 35 are arranged.

As the fuser 35, for example, a fixing belt having a belt shape using a fluororesin component or a low surface energy material typified by a silicone resin on the surface, and a fluororesin component or a silicone resin on the surface are typified. Examples thereof include a cylindrical fixing roll using a low surface energy material.

Next, the operation of each image forming unit 50Y, 50M, 50C, 50K, 50B for forming an image of each color of yellow, magenta, cyan, black, and white or brilliant will be described. Since the operations of the image forming units 50Y, 50M, 50C, 50K, and 50B are the same, the operation of the yellow image forming unit 50Y will be described as a representative example.

In the yellow developing unit 50Y, the photoconductor 21Y rotates at a predetermined process speed in the direction of arrow A. The charging roll 28Y negatively charges the surface of the photoconductor 21Y to a predetermined potential. After that, the surface of the photoconductor 21Y is exposed by the exposure apparatus 19Y, and a static charge image corresponding to the image information is formed. Subsequently, the negatively charged toner is reverse-developed by the developing apparatus 20Y, and the electrostatic charge image formed on the surface of the photoconductor 21Y is visualized on the surface of the photoconductor 21Y to form a toner image. After that, the toner image on the surface of the photoconductor 21Y is primarily transferred to the surface of the intermediate transfer belt 33 by the primary transfer roll 17Y. After the primary transfer, the transfer residual components such as toner remaining on the surface of the photoconductor 21Y are scraped off by the cleaning blade of the cleaning device 15Y and cleaned to prepare for the next image forming step.

The above operation is performed in each image forming unit 50Y, 50M, 50C, 50K, 50B, and the toner images visualized on the surfaces of the photoconductors 21Y, 21M, 21C, 21K, 21B are sequentially transferred to the intermediate transfer belt. Multiple transfer is performed on the 33 surface. In color mode, toner images of each color are multiple-transferred in the order of yellow, magenta, cyan, black, and white or brilliant (for example, silver), but this order is also required in two-color and three-color mode. Only toner images of different colors will be transferred individually or multiple times. After that, the toner image transferred alone or multiple times on the surface of the intermediate transfer belt 33 is secondarily transferred by the secondary transfer roll 34 to the surface of the recording paper P conveyed from the paper cassette (not shown), and subsequently, the fixing device 35. It is fixed by heating and pressurizing in. The toner remaining on the surface of the intermediate transfer belt 33 after the secondary transfer is cleaned by a belt cleaner 26 composed of a cleaning blade for the intermediate transfer belt 33.

<Toner cartridge>
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 contains a replenishing toner for supplying to the developing means provided in the image forming apparatus.

In FIG. 6, the toner cartridges 40Y, 40M, 40C, 40K, and 40B contain toners of each color, and are connected to a developing device corresponding to each color by a toner supply pipe (not shown). Further, the toner cartridges 40Y, 40M, 40C, 40K and 40B are toner cartridges that are attached to and detached from the image forming apparatus, and when the amount of toner stored in each toner cartridge is low, the toner cartridge can be replaced. To be done.

<Process 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 thereto. The main parts shown in the figure will be described, and the description thereof will be omitted for the others.

FIG. 7 is a schematic configuration diagram showing a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 7 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. 7, 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.

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 "%" are based on mass.

(Preparation of white pigment dispersion liquid (1))
-Titanium oxide (CR-60-2: manufactured by Ishihara Sangyo Co., Ltd.): 100 parts-Nonionic surfactant (Nonipol 400: manufactured by Sanyo Kasei Kogyo Co., Ltd.): 10 parts-Ion exchanged water: 400 parts or more The components are mixed, stirred for 30 minutes using a homogenizer (Ultratalax T50: manufactured by IKA), and then dispersed for 1 hour with a high-pressure impact disperser Ultimizer (HJP30006: manufactured by Sugino Machine). A white pigment dispersion liquid (1) (solid content concentration: 20%) in which a white pigment having a volume average particle diameter of 210 nm was dispersed was prepared.

(Preparation of metal pigment dispersion)
-Aluminum pigment (manufactured by Showa Aluminum Powder Co., Ltd., 2173EA): 100 parts-Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen R): 1.5 parts-Ion exchange water: 400 parts From aluminum pigment paste The solvent was removed, and the aluminum pigment was mechanically pulverized and classified using a star mill (LMZ, manufactured by Ashizawa Finetech Co., Ltd.). Then, it is mixed with a surfactant and ion-exchanged water and dispersed for 1 hour using an emulsification disperser Cavitron (manufactured by Pacific Kiko Co., Ltd., CR1010) to disperse metal pigment particles (aluminum pigment). A dispersion was prepared (solid content concentration: 20%). The volume average particle diameter of the metal pigment particles was 15 μm.

(Preparation of cyan pigment dispersion for comparison)
・ Cyan pigment (manufactured by Dainichiseika Co., Ltd., product name: CI Pigment Blue 15: 3): 100 parts ・ Nonionic surfactant (Nonipol 400: manufactured by Sanyo Kasei Kogyo Co., Ltd.): 10 parts ・ Ion exchange Water: 400 parts or more of the components are mixed and stirred using a homogenizer (Ultratarax T50: manufactured by IKA) for 30 minutes, and then with a high-pressure impact disperser Ultimizer (HJP30006: manufactured by Sugino Machine Limited). The dispersion treatment was carried out for 1 hour to prepare a cyan pigment dispersant (solid content concentration: 20%) for comparison.

(Preparation of release agent dispersion)
-Polyethylene wax (manufactured by Toyo Adre Co., Ltd., product name: PW655, melting temperature: 97 ° C.): 50 parts-Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1.0 part-sodium chloride (Manufactured by Wako Pure Chemical Industries, Ltd.): 5 parts, ion-exchanged water: 200 parts or more were mixed and heated to 95 ° C., and dispersed using a homogenizer (manufactured by IKA, Ultratarax T50). Then, a release treatment is carried out with a Manton Gorin high-pressure homogenizer (Gorlin Co., Ltd.) for 360 minutes to disperse a release agent having a volume average particle size of 0.23 μm (solid content concentration: 20%). Was prepared.

(Synthesis of amorphous polyester resin)
-Bisphenol A ethylene oxide 2.2 mol Adduct: 40 mol%
-Bisphenol A Propylene Oxide 2.2 mol Adduct: 60 mol%
・ Terephthalic acid: 47 mol%
・ Fumaric acid: 40 mol%
Dodecenyl succinic anhydride: 15 mol%
-Trimellitic acid anhydride: 3 mol%
In a reaction vessel equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introduction tube, 0 parts of the above-mentioned monomer components other than fumaric acid and trimellitic acid anhydride and tin dioctanoate were added to a total of 100 parts of the above-mentioned monomer components. .25 copies were put in. After reacting at 235 ° C. for 6 hours under a nitrogen gas stream, the temperature was lowered to 200 ° C., and the above fumaric acid and trimellitic acid anhydride were added and reacted for 1 hour. The temperature was further raised to 220 ° C. over 4 hours and polymerized under a pressure of 10 kPa to a desired molecular weight to obtain a pale yellow transparent amorphous polyester resin.
The obtained amorphous polyester resin has a glass transition temperature Tg of 59 ° C. by DSC, a weight average molecular weight Mw of 25,000 by GPC, a number average molecular weight Mn of 7,000, a softening temperature of 107 ° C. by a flow tester, and an acid. The value AV was 13 mgKOH / g.

(Preparation of amorphous polyester resin dispersion)
A 3-liter reaction tank with a jacket (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dripping device, and an anchor wing is maintained at 40 ° C. in a water circulation type constant temperature bath. A mixed solvent of 160 parts of ethyl acetate and 100 parts of isopropyl alcohol was added thereto, and 300 parts of the above amorphous polyester resin was added thereto, and the mixture was stirred at 150 rpm using a three-one motor and dissolved to obtain an oil phase. It was. 14 parts of a 10% aqueous ammonia solution was added dropwise to the stirred oil phase at a dropping time of 5 minutes, and after mixing for 10 minutes, 900 parts of ion-exchanged water was further added dropwise at a rate of 7 parts per minute 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 a 2 liter 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 liquid. The obtained dispersion had no solvent odor. The volume average particle diameter of the resin particles in this dispersion was 130 nm.
Then, ion-exchanged water was added to prepare a solid content concentration of 20%, which was used as an amorphous polyester resin dispersion.

(Synthesis of crystalline polyester resin (1))
1,10-dodecanedioic acid: 50 mol%
-1,9-Nonanediol: 50 mol%
The above monomer component is placed in a reaction vessel equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introduction tube, the inside of the reaction vessel is replaced with dry nitrogen gas, and then titanium tetrabutoxide (reagent) is added to 100 parts of the monomer component. On the other hand, 0.25 copies were added. After a stirring reaction at 170 ° C. for 3 hours under a nitrogen gas stream, the temperature was further raised to 210 ° 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 crystallize. A sex polyester resin (1) was obtained.
The obtained crystalline polyester resin (1) has a melting temperature of 73.6 ° C. by DSC, a mass average molecular weight Mw of 25,000 by GPC, a number average molecular weight of Mn of 10,500, and an acid value of AV of 10.1 mgKOH /. It was g.

(Preparation of crystalline polyester resin dispersion liquid (1))
In a 3-liter 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 the crystalline polyester resin (1) and methyl ethyl ketone (solvent). ) 160 parts and 100 parts of isopropyl alcohol (solvent) were 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.
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./ A total of 900 parts were added dropwise at a rate of 1 minute 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 a 2 liter 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 liquid. The obtained dispersion had no solvent odor. The volume average particle diameter of the resin particles in this dispersion was 130 nm. Then, ion-exchanged water was added to prepare a solid content concentration of 20%, which was used as a crystalline polyester resin dispersion.

(Synthesis of crystalline polyester resin (2))
The same procedure as for the synthesis of the crystalline polyester resin (1) was carried out except that the 1,10-dodecanedic acid used for the crystalline polyester resin (1) was changed to dimethyl terephthalate to obtain the crystalline polyester resin (2). It was.
The obtained crystalline polyester resin (2) had a melting temperature of 55 ° C. by DSC, a mass average molecular weight Mw by GPC of 24,000, a number average molecular weight Mn of 10,000, and an acid value AV of 11.0 mgKOH / g. there were.

(Preparation of crystalline polyester resin dispersion liquid (2))
The preparation was carried out in the same manner as in the preparation of the crystalline polyester resin dispersion liquid (1) except that the crystalline polyester resin (2) was used.
The volume average particle diameter of the resin particles in this dispersion was 130 nm. Then, ion-exchanged water was added to adjust the solid content concentration to 20%, which was used as the crystalline polyester resin dispersion liquid (2).

(Synthesis of crystalline polyester resin (3))
Synthesis of crystalline polyester resin (1) except that 1,10-dodecanedioic acid used for crystalline polyester resin (1) was changed to fumaric acid and 1,9-nonanediol was changed to 1,10-decanediol. The same procedure as above was carried out to obtain a crystalline polyester resin (3).
The obtained crystalline polyester resin (3) had a melting temperature of 91 ° C. by DSC, a mass average molecular weight Mw by GPC of 31,000, a number average molecular weight Mn of 9,000, and an acid value AV of 11.2 mgKOH / g. there were.

(Preparation of crystalline polyester resin dispersion liquid (3))
The preparation was carried out in the same manner as in the preparation of the crystalline polyester resin dispersion liquid (1) except that the crystalline polyester resin (3) was used.
The volume average particle diameter of the resin particles in this dispersion was 150 nm. Then, ion-exchanged water was added to adjust the solid content concentration to 20%, and this was used as a crystalline polyester resin dispersion liquid (3).

(Preparation of crystalline styrene acrylic resin dispersion)
・ Styrene: 100 parts ・ Vinyl stearate: 208 parts ・ n-Butyl acrylate: 100 parts ・ Acrylic acid: 4 parts ・ Dodecanethiol: 6 parts ・ Propanediol diacrylate: 1.5 parts The above components were mixed and dissolved. The mixture was added to an aqueous solution prepared by dissolving 4 parts of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) in 550 parts of ion-exchanged water, emulsioned in a flask, and then mixed for 10 minutes. An aqueous solution prepared by dissolving 6 parts of ammonium persulfate in 100 parts of ion-exchanged water was added thereto, and after nitrogen substitution, the inside of the flask was heated with an oil bath until the contents reached 75 ° C. and left as it was for 5 hours. Emulsion polymerization was continued. In this way, a crystalline styrene acrylic resin dispersion (resin particle concentration: 20%) was obtained by dispersing resin particles having an average particle size of 190 nm and a weight average molecular weight (Mw) of 35,000. The melting temperature of the crystalline styrene acrylic resin was 62 ° C.

(Preparation of amorphous styrene acrylic resin dispersion)
・ Styrene: 308 parts ・ n-Butyl acrylate: 100 parts ・ Acrylic acid: 4 parts ・ Dodecanethiol: 6 parts ・ Propanediol diacrylate: 1.5 parts (Manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 4 parts were put into an aqueous solution dissolved in 550 parts of ion-exchanged water, emulsified in a flask, and then 6 parts of ammonium persulfate was added thereto while mixing for 10 minutes. After adding the dissolved aqueous solution to 100 parts of ion-exchanged water and substituting with nitrogen, the inside of the flask was heated with an oil bath while stirring until the contents reached 75 ° C., and the emulsification polymerization was continued as it was for 5 hours. In this way, an amorphous styrene acrylic resin dispersion (resin particle concentration: 20%) obtained by dispersing resin particles having an average particle size of 195 nm and a weight average molecular weight (Mw) of 34,000 was obtained. The glass transition temperature of the amorphous styrene acrylic resin was 52 ° C.

[Example 1]
100 parts of amorphous polyester resin dispersion liquid, 250 parts of white pigment dispersion liquid (1) and 4 parts of anionic surfactant (TaycaPower, manufactured by Teika Co., Ltd.) are placed in a round stainless steel flask, and 0.1 N nitrate is added. After the addition to adjust the pH to 4.0, 0.2 part of a nitrate aqueous solution having a polyamorphous aluminum chloride concentration of 10% was added. Subsequently, the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer (Ultratarax T50 manufactured by IKA).
Next, 300 parts of the amorphous polyester resin dispersion liquid, 100 parts of the crystalline polyester resin dispersion liquid (1), 250 parts of the white pigment dispersion liquid (1), and 70 parts of the release agent dispersion liquid were added to the slurry dispersed above. Was added, and 0.1N of nitrate was further added to adjust the pH to 4.0, then 2.8 parts of an aqueous nitrate solution having a polyamorphous aluminum chloride concentration of 10% was added, and the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer. After that, it was heated to 45 ° C. in a heating oil bath and held for 30 minutes. After that, 100 parts of an amorphous polyester resin dispersion was added and held for 1 hour, a 0.1 N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then the mixture was heated to 73 ° C. while continuing stirring. And held for 5 hours. Then, the toner particles (1) having a volume average particle diameter of 7.5 μm were obtained by cooling to 20 ° C. at a rate of 20 ° C./min, filtering, thoroughly washing with ion-exchanged water, and drying.

(Making toner)
100 parts of toner particles (1) and 0.7 parts of dimethyl silicone oil-treated silica particles (RY200 manufactured by Nippon Aerosil Co., Ltd.) were mixed using a Henshell mixer to obtain toner (1).

(Preparation of developer)
-Ferrite particles (average particle size 50 μm): 100 parts-Toluene: 14 parts-styrene / methyl methacrylate copolymer (copolymerization ratio 15/85): 3 parts-Carbon black: 0.2 parts The above components excluding ferrite particles Was dispersed in a sand mill to prepare a dispersion, and the dispersion was placed in a vacuum degassing type kneader together with ferrite particles, and the pressure was reduced while stirring to dry the mixture to obtain a carrier.
Then, 8 parts of the toner (1) was mixed with 100 parts of the carrier to obtain a developer (1).

The obtained toner (1) has a temperature raising step of raising the temperature from 0 ° C. to 150 ° C. at a heating rate of 10 ° C./min and a temperature lowering step of lowering the temperature from 150 ° C. to 0 ° C. at a temperature lowering rate of -10 ° C./min. Differential scanning calorimetry (DSC) performed with the steps was performed by the method described above.
Further, the same DSC measurement was performed on the toners obtained in each of the following Examples and Comparative Examples.
Whether or not the endothermic peak Tm derived from the crystalline resin is present in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature raising step, and whether or not the heat absorption peak Tc derived from the crystalline resin is present in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature lowering step. Whether or not, the peak temperature and peak calorific value of the exothermic peak Tc, the ratio of the peak calorific value Qc of the exothermic peak Tc to the peak calorific value Qm of the endothermic peak Tm [Qc / Qm], and the content Cr (mass) of the crystalline resin in the toner particles. %) The ratio of the peak calorific value Qc of the exothermic peak Tc [Qc / Cr] is shown in Table 1.

[Example 2]
In Example 1, except that the crystalline polyester resin dispersion liquid (1) was changed to the crystalline polyester resin dispersion liquid (3) and the heating temperature after adjusting the pH to 8.5 was set to 90 ° C. Toner particles (2) were prepared in the same manner as in Example 1 to obtain a developer (2).

[Example 3]
100 parts of amorphous polyester resin dispersion, 400 parts of white pigment dispersion (1), 20 parts of crystalline polyester resin (1), and 4 parts of anionic surfactant (TaycaPower, manufactured by Teika) are made of round stainless steel. The mixture was placed in a flask and adjusted to pH 4.0 by adding 0.1 N nitric acid, and then 0.2 part of an aqueous nitric acid solution having a polyamorphous aluminum chloride concentration of 10% was added. Subsequently, the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer (Ultratarax T50 manufactured by IKA).
Next, 300 parts of the amorphous polyester resin dispersion liquid, 80 parts of the crystalline polyester resin dispersion liquid (1), and 70 parts of the release agent dispersion liquid were added to the slurry dispersed above, and 0.1 N nitrate was further added. Was added to adjust the pH to 4.0, then 2.8 parts of a nitrate aqueous solution having a polyamorphous aluminum chloride concentration of 10% was added, dispersed at 30 ° C. for 5 minutes using a homogenizer, and then 45 in a heating oil bath. It was heated to ° C. and held for 30 minutes. After that, 100 parts of an amorphous polyester resin dispersion was added and held for 1 hour, a 0.1 N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then the mixture was heated to 54 ° C. while continuing stirring. And held for 15 hours. Then, the toner particles (3) having a volume average particle diameter of 7.5 μm were obtained by cooling to 20 ° C. at a rate of 20 ° C./min, filtering, thoroughly washing with ion-exchanged water, and drying.
Then, a developer was prepared using the toner particles (3) in the same manner as in Example 1 to obtain a developer (3).

[Example 4]
100 parts of amorphous polyester resin dispersion, 250 parts of white pigment dispersion (1), 20 parts of crystalline polyester resin (1), and 4 parts of anionic surfactant (TaycaPower, manufactured by Teika) are made of round stainless steel. The mixture was placed in a flask and adjusted to pH 4.0 by adding 0.1 N nitric acid, and then 0.2 part of an aqueous nitric acid solution having a polyamorphous aluminum chloride concentration of 10% was added. Subsequently, the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer (Ultratarax T50 manufactured by IKA).
Next, 300 parts of the amorphous polyester resin dispersion liquid, 250 parts of the crystalline polyester resin dispersion liquid (1), 80 parts of the white pigment dispersion liquid (1), and 70 parts of the release agent dispersion liquid were added to the slurry dispersed above. Was added, and 0.1N of nitrate was further added to adjust the pH to 4.0, then 2.8 parts of an aqueous nitrate solution having a polyamorphous aluminum chloride concentration of 10% was added, and the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer. After that, it was heated to 45 ° C. in a heating oil bath and held for 30 minutes. After that, 100 parts of an amorphous polyester resin dispersion was added and held for 1 hour, a 0.1 N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then the mixture was heated to 73 ° C. while continuing stirring. And held for 15 hours. Then, the toner particles (4) having a volume average particle diameter of 7.5 μm were obtained by cooling to 20 ° C. at a rate of 20 ° C./min, filtering, thoroughly washing with ion-exchanged water, and drying.
Then, a developer was prepared using the toner particles (4) in the same manner as in Example 1 to obtain a developer (4).

[Example 5]
In Example 1, toner particles (5) were prepared in the same manner as in Example 1 except that the heating temperature after adjusting the pH to 8.5 was 70 ° C. and the holding time was 10 hours. (5) was obtained.

[Example 6]
In Example 1, toner particles (6) were prepared in the same manner as in Example 1 except that the heating temperature after adjusting the pH to 8.5 was 73 ° C. and the holding time was 24 hours. (6) was obtained.

[Example 7]
In Example 1, toner particles (7) were prepared in the same manner as in Example 1 except that the heating temperature after adjusting the pH to 8.5 was 66 ° C. and the holding time was 12 hours. (7) was obtained.

[Example 8]
Toner particles (8) were produced in the same manner as in Example 1 except that the white pigment dispersion liquid (1) used for producing the toner particles was changed to "metal pigment dispersion liquid" in Example 1. , The developer (8) was obtained.

[Example 9]
Toner particles were prepared in the same manner as in Example 1 except that the preparation of toner particles was changed to the following method in Example 1 to obtain a developer.
(Preparation of toner particles)
-Amorphous styrene acrylic resin dispersion: 500 parts-Crystalline styrene acrylic resin dispersion: 100 parts-White pigment dispersion (1): 500 parts-Release release agent dispersion: 70 parts Acrylic styrene acrylic resin dispersion 100 parts of the liquid, 250 parts of the white pigment dispersion liquid (1), and 4 parts of an anionic surfactant (TaycaPower, manufactured by Teika Co., Ltd.) are placed in a round stainless steel flask, 0.1 N nitrate is added, and the pH is 4.0. After adjusting to, 0.2 part of a nitrate aqueous solution having a polyaluminum chloride concentration of 10% was added. Subsequently, the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer (Ultratarax T50 manufactured by IKA).
Next, 300 parts of the amorphous styrene acrylic resin dispersion liquid, 100 parts of the crystalline styrene acrylic resin dispersion liquid, 250 parts of the white pigment dispersion liquid (1), and 70 parts of the release agent dispersion liquid were added to the slurry dispersed above. After the addition, 0.1 N of nitrate was further added to adjust the pH to 4.0, then 2.8 parts of a nitrate aqueous solution having a polyaluminum chloride concentration of 10% was added, and the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer. Then, it was heated to 45 ° C. in a heating oil bath and held for 30 minutes. Then, 100 parts of an amorphous styrene acrylic resin dispersion was added and held for 1 hour, and a 0.1 N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then the pH was adjusted to 73 ° C. while continuing stirring. It was heated and held for 5 hours. Then, the toner particles (9) having a volume average particle diameter of 7.5 μm were obtained by cooling to 20 ° C. at a rate of 20 ° C./min, filtering, thoroughly washing with ion-exchanged water, and drying. Using the toner particles (9), a developer (9) was obtained in the same manner as in Example 1.

[Example 10]
(Preparation of toner particles / kneading and crushing method)
100 parts of the amorphous polyester resin, 20 parts of the crystalline polyester resin, 100 parts of titanium oxide (CR-60-2: manufactured by Ishihara Sangyo Co., Ltd.), and polyethylene wax (manufactured by Toyo Adre Co., Ltd., product name: PW655). ) 14 parts of the mixture was premixed with a 75L Henschel mixer, and then kneaded under the following conditions with a biaxial continuous kneader having a screw structure to obtain a kneaded product. Specifically, kneading was performed under the conditions of a kneading temperature of 160 ° C., a rotation speed of 280 rpm, and a kneading speed of 90 kg / h.
The obtained kneaded product is crushed using a 400AFG-CR crusher (manufactured by Hosokawa Micron), and then fine powder and coarse powder are removed using an pneumatic elbow jet classifier (manufactured by Matsubo) to remove toner particles (manufactured by Matsubo). 10) was obtained.
Next, heating (post-annealing) was carried out under the condition of 73 ° C. for 120 minutes to obtain toner particles having a volume average particle size of 15 μm.
A toner was prepared in the same manner as in Example 1 except that the toner particles (10) were used, and a developer was obtained.

[Example 11]
(Preparation of unmodified polyester resin (1))
-Terephthalic acid: 1243 parts-Bisphenol A ethylene oxide adduct: 1830 parts-Bisphenol A propylene oxide adduct: 840 parts After heating and mixing the above components at 180 ° C, add 3 parts of dibutyltin oxide and heat at 220 ° C. While distilling off water, an unmodified polyester resin (1) was obtained. The glass transition temperature Tg of the obtained unmodified polyester resin (1) was 60 ° C., the acid value was 3 mgKOH / g, and the hydroxyl value was 1 mgKOH / g.

(Preparation of Isocyanate-Modified Polyester Prepolymer (1))
-Terephthalic acid: 1243 parts-Bisphenol A ethylene oxide adduct: 1830 parts-Bisphenol A propylene oxide adduct: 840 parts After heating and mixing the above components at 180 ° C, add 3 parts of dibutyltin oxide and heat at 220 ° C. While distilling off water, a polyester prepolymer was obtained. 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 an isocyanate-modified polyester prepolymer (1) having an isocyanate group. It was.

(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 crystalline polyester resin (4))
・ 1,10-decandycarboxylic acid: 350 parts ・ 1,4-Butanediol: 115 parts Put the above-mentioned monomer component into a reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas introduction tube, and put the above-mentioned monomer component into the reaction vessel. Was replaced with dry nitrogen gas, and then 0.6 part of tin dioctanoate was added to 100 parts of the monomer component. After a stirring reaction at 150 ° C. for 3 hours under a nitrogen gas stream, the temperature was further raised to 170 ° C. over 2 hours, the inside of the reaction vessel was reduced to 3 kPa, and the reaction vessel was further stirred for 2 hours and then cooled. The reaction was completed to obtain a crystalline polyester resin (4).

(Preparation of white pigment dispersion liquid (2))
-Titanium oxide (CR-60-2: manufactured by Ishihara Sangyo Co., Ltd.): 100 parts-Ethyl acetate: 500 parts The operation of mixing the above components, filtering the mixture and further mixing with 500 parts of ethyl acetate is repeated 5 times. After that, the mixture was dispersed for about 1 hour using an emulsification disperser Cavitron (CR1010 manufactured by Pacific Machinery & Engineering Co., Ltd.) to obtain a white pigment dispersion (2) (solid content concentration: 20%) in which acid value titanium was dispersed. It was.

(Preparation of release agent dispersion liquid (2))
-Polyethylene wax (manufactured by Baker Petrolite, product name: PW600, melting point: 88 ° C): 30 parts-Ethyl acetate: 270 parts With the above components cooled to 10 ° C, a microbead type disperser (DCP mill) is used. Wet pulverization was performed to obtain a release agent dispersion liquid (2).

(Preparation of oil phase liquid (1))
-Unmodified polyester resin (1): 136 parts-Crystalline polyester resin (1): 20 parts-White pigment dispersion liquid (2): 500 parts-Ethyl acetate: 56 parts The mixture obtained after stirring and mixing the above components. 75 parts of the release agent dispersion liquid (2) was added to the mixture, and the mixture was stirred to obtain an oil phase liquid (1).

(Preparation of aqueous phase liquid (1))
・ Amorphous styrene acrylic resin particle dispersion: 120 parts ・ 2% aqueous solution of cellogen BS-H (Daiichi Kogyo Seiyaku Co., Ltd.): 200 parts ・ Ion-exchanged water: 200 parts Stirring and mixing the above components, aqueous phase Liquid (1) was obtained.

(Preparation of toner particles)
-Oil phase liquid (1): 300 parts-Isocyanate-modified polyester prepolymer (1): 50 parts-Ketimine compound (1): 5 parts Put the above ingredients in a container and use a homogenizer (Ultratalax: manufactured by IKA) to 2 parts. After stirring for 1 minute to obtain an oil phase liquid (1P), 1000 parts of the aqueous phase liquid (1) was added to the container, and the mixture was stirred with a homogenizer for 20 minutes. Next, the mixture is stirred with a propeller-type stirrer at room temperature (25 ° C.) and normal pressure (1 atm) for 48 hours to react the isocyanate-modified polyester prepolymer (1) with the ketimine compound (1), and urea. A modified polyester resin was produced, and the organic solvent was removed to form granules. The granules were then washed with water, dried and classified.

(Post-annealing process)
Next, heating (post-annealing) was carried out under the condition of 73 ° C. for 120 minutes to obtain toner particles having a volume average particle size of 7.5 μm.

A toner was prepared in the same manner as in Example 1 except that the toner particles were used, and a developer was obtained.

[Comparative Example 1]
(Preparation of toner particles / aggregation and coalescence method)
・ Amorphous polyester resin dispersion: 600 parts ・ White pigment dispersion (1): 500 parts ・ Release agent dispersion: 70 parts ・ Anionic surfactant (TaycaPower, manufactured by Teika): 4 parts Crystalline polyester Toner particles were prepared in the same manner as in Example 1 except that an amorphous polyester resin dispersion was used instead of the resin dispersion (1) to obtain a developer.

[Comparative Example 2]
(Preparation of toner particles / aggregation and coalescence method)
-Amorphous polyester resin dispersion: 500 parts-Crystalular polyester resin dispersion: 100 parts-Cyan pigment dispersion for comparison: 500 parts-Release release agent dispersion: 70 parts-Anionic surfactant (TaycaPower, (Manufactured by Teika): Toner particles were prepared in the same manner as in Example 1 except that a comparative cyan pigment dispersion was used instead of the four-part white pigment dispersion (1) to obtain a developer.

[Comparative Example 3]
100 parts of amorphous polyester resin dispersion, 250 parts of white pigment dispersion (1), 50 parts of crystalline polyester resin (2), and 4 parts of anionic surfactant (TaycaPower, manufactured by Teika) are made of round stainless steel. The mixture was placed in a flask and adjusted to pH 4.0 by adding 0.1 N nitric acid, and then 0.2 part of an aqueous nitric acid solution having a polyamorphous aluminum chloride concentration of 10% was added. Subsequently, the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer (Ultratarax T50 manufactured by IKA).
Next, 300 parts of the amorphous polyester resin dispersion liquid, 250 parts of the crystalline polyester resin dispersion liquid (2), 50 parts of the white pigment dispersion liquid (1), and 70 parts of the release agent dispersion liquid were added to the slurry dispersed above. Was added, and 0.1N of nitrate was further added to adjust the pH to 4.0, then 2.8 parts of an aqueous nitrate solution having a polyamorphous aluminum chloride concentration of 10% was added, and the mixture was dispersed at 30 ° C. for 5 minutes using a homogenizer. After that, it was heated to 45 ° C. in a heating oil bath and held for 30 minutes. After that, 100 parts of an amorphous polyester resin dispersion was added and held for 1 hour, a 0.1 N aqueous sodium hydroxide solution was added to adjust the pH to 8.5, and then the mixture was heated to 73 ° C. while continuing stirring. And held for 15 hours. Then, the toner particles were cooled to 20 ° C. at a rate of 20 ° C./min, filtered, thoroughly washed with ion-exchanged water, and dried to obtain toner particles having a volume average particle size of 7.5 μm. Then, a developer was prepared in the same manner as in Example 1 to obtain a developer.

(Evaluation)
・ Light reflectivity test (L ^* concealment)
The light reflectivity (L ^* concealment) was evaluated by the following method.
^{The L *} of the image fixed on the black paper at a concentration of 11 g / m ² and a speed of 175 mm / s was measured with an optical densitometer manufactured by X-Rite, and the following evaluation criteria were followed.
-Evaluation criteria-
A: L ^* = 80 or more B: L ^* = 79 or more and 80 or less C: L ^* = 76 or more and 79 or less D: L ^* = less than 76, a level that cannot be used in actual use

・ Low temperature fixability test The developer of the color copier DocuCenterColor400 (manufactured by Fuji Xerox Co., Ltd.) from which the fuser was taken out was filled with the obtained developer and adjusted so ^{that the toner loading amount was 0.45 mg / cm 2.} An unfixed image was output. As a recording medium, JD paper A4 size (basis weight 157 gsm) manufactured by Fuji Xerox Co., Ltd. was used. The output image is an image having a size of 50 mm × 50 mm and an image density of 100%.
As the fixing evaluation device, a fixing device of ApeosPort IV C3370 manufactured by Fuji Xerox Co., Ltd. was removed and modified so that the fixing temperature could be changed. The process speed was 175 mm / sec.
Under these conditions, the unfixed image was fixed by changing the temperature of the fixing device from 110 ° C. to 200 ° C. by 5 ° C. to obtain a fixed image. The fixed image portion was bent using a weight, and the degree of image loss in that portion was visually evaluated. The lowest temperature among the temperatures at which image defects could not be visually confirmed was defined as the lowest fixing temperature.
-Evaluation criteria-
A: Minimum fixing temperature = less than 130 ° C B: Minimum fixing temperature = 130 ° C or more and 140 ° C or less C: Minimum fixing temperature = above 140 ° C

・ Bending workability test The developer of the color copier DocuCenterColor400 (manufactured by Fuji Xerox Co., Ltd.) from which the fuser was taken out was filled with the obtained developer and adjusted so ^{that the toner loading amount was 0.45 mg / cm 2.} An unfixed image was output. As a recording medium, JD paper A4 size (basis weight 157 gsm) manufactured by Fuji Xerox Co., Ltd. was used. The output image was an image having an image density of 50 mm × 50 mm and an image density of 100%.
As the fixing evaluation device, a fixing device of ApeosPort IV C3370 manufactured by Fuji Xerox Co., Ltd. was removed and modified so that the fixing temperature could be changed. The process speed was 175 mm / sec and the fixing temperature was 150 ° C.
The output solid image is ^{pressed under the condition of 40 g / cm 2} for 30 seconds while being bent inward, reopened, and the damaged image is wiped off with a soft cloth. It was set as the value of bending resistance. The results are shown in Table 1.
In Table 1, the maximum value of the width of the image defect is "A" if it is 0.4 mm or less, more than 0.4 mm, "B" if it is 0.7 mm or less, and more than 0.7 mm. "C" was displayed.

11 Screw extruder 12 Barrel 14 Injection port 15Y, 15M, 15C, 15K, 15B Cleaning device 16 Liquid addition port 17Y, 17M, 17C, 17K, 17B Primary transfer roll 18 Discharge port 19Y, 19M, 19C, 19K, 19B Exposure device 20Y, 20M, 20C, 20K, 20B Developer 21Y, 21M, 21C, 21K, 21B Photoreceptor 22 Drive roll 23 Support roll 24 Bias roll 26 Belt cleaner 28Y, 2M8, 28C, 28K, 28B Charge roll 33 Intermediate transfer belt 34 Secondary transfer roll 35 Fixer 40Y, 40M, 40C, 40K, 40B Toner cartridge 50Y, 50M, 50C, 50K, 50B Image forming unit 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 (9)

It has toner particles containing at least a crystalline resin and at least one pigment selected from inorganic pigments and metal pigments.
Differential scanning calorimetry (DSC), which involves a heating step of raising the temperature from 0 ° C. to 150 ° C. at a heating rate of 10 ° C./min and a temperature lowering step of lowering the temperature from 150 ° C. to 0 ° C. at a temperature lowering rate of -10 ° C./min. In the heating step, the heat absorption peak Tm derived from the crystalline resin is present in the region of 55 ° C. or higher and 85 ° C. or lower, and the heat generated by the crystalline resin is generated in the region of 55 ° C. or higher and 85 ° C. or lower during the temperature lowering step. have a peak Tc,
A toner for developing an electrostatic charge image in which the ratio [Qc / Qm] of the peak calorific value Qc of the exothermic peak Tc to the peak calorific value Qm of the endothermic peak Tm is 5 × 10 ^{-4 or more.} The toner for static charge image development according to claim 1, wherein the peak calorific value Qc of the exothermic peak Tc is 5 × 10 ^-3 J / g or more and 10 J / g or less. The ratio [Qc / Qm] of the peak calorific value Qc of the exothermic peak Tc to the peak calorific value Qm of the endothermic peak Tm is 0 . 8. The toner for developing an electrostatic charge image according to claim 1 or 2, which is 8 or less. Claim 1 in which the ratio [Qc / Cr] of the peak calorific value Qc of the exothermic peak Tc to the content Cr (mass%) of the crystalline resin in the toner particles is 5 × 10 ^-4 or more and 1.0 or less. The toner for developing an electrostatic charge image according to any one of claims 3. A static charge image developer containing the toner for static charge image development according to any one of claims 1 to 4. The toner for developing an electrostatic charge image according to any one of claims 1 to 4 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 5 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 for accommodating the electrostatic charge image developer according to claim 5 and developing 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 by heating,
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 5.
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 by heating, and
An image forming method having.

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