JP7306056B2 - Electrostatic charge image developing toner, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

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

Patent Document 1 discloses that the binder resin contains a block copolymer having a crystalline polyester block and a non-crystalline polyester block, and the crystals of the toner measured with a differential scanning calorimeter. When the melting point peak area based on the crystalline polyester block is Q1, and the melting point peak area based on the crystalline polyester block when the toner after storage at 50°C for one week is measured with a differential scanning calorimeter is Q2, Q2/Q1. is 1.0 or more and 1.2 or less.

JP 2014-164064 A

An object of the present invention is to provide toner particles containing an amorphous resin, a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms, and an external additive. , When the external additive contains only silica particles having a BET specific surface area of less than 100 m ² /g, or in differential scanning calorimetry according to ASTM D3418-8, the first The endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the heating process is ΔH1 (mW/g), and the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the second heating process is ΔH2 ( mW/g), electrostatic charge image development that suppresses detachment of the external additive from the toner particles compared to the case where the formula: 0.05>ΔH2/ΔH1 or the formula: ΔH2/ΔH1>0.95 is satisfied. It is to provide a toner for

Specific means for solving the above problems include the following aspects.

<1> Toner particles containing an amorphous resin and a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms;
an external additive containing silica particles having a BET specific surface area of 100 m ² /g or more;
has
In differential scanning calorimetry in accordance with ASTM D3418-8 (2008), the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first heating process is ΔH1 (mW / g), and the second heating. A toner for electrostatic charge image development satisfying the formula: 0.05≦ΔH2/ΔH1≦0.95, where ΔH2 (mW/g) is the heat absorption amount based on the heat absorption peak derived from the crystalline polyester resin in the process.
<2> The electrostatic image developing toner according to <1>, which satisfies the formula: 0.35<ΔH2/ΔH1≦0.95.
<3> The electrostatic image developing toner according to <2>, which satisfies the formula: 0.45<ΔH2/ΔH1≦0.80.
<4> The electrostatic image developing toner according to <1>, which satisfies the formula: 0.05≦ΔH2/ΔH1≦0.35.
<5> The electrostatic image developing toner according to <4>, which satisfies the formula: 0.15≦ΔH2/ΔH1<0.25.
<6> The toner for electrostatic charge image development according to any one of <1> to <5>, wherein the silica particles have an average primary particle size of 20 nm or more and 90 nm or less.
<7> The toner for electrostatic charge image development according to any one of <1> to <6>, wherein the silica particles are sol-gel silica particles.
<8> The electrostatic image developing toner according to any one of <1> to <7>, wherein the external additive has a coverage of 80% or more.
<9> The static image forming apparatus according to any one of <1> to <8>, wherein the toner for developing an electrostatic charge image stored for 24 hours in an environment of a temperature of 50° C. and a humidity of 50% has a fluidity index of 20 or less. Toner for charge image development.
<10> The electrostatic image developing toner according to any one of <1> to <9>, which contains a low-molecular-weight siloxane having a molecular weight of 200 or more and 600 or less, which is composed only of a siloxane bond and an alkyl group.
<11> The electrostatic image developing toner according to <10>, wherein the low-molecular-weight siloxane is a low-molecular-weight siloxane having a tetrakis structure.
<12> The electrostatic image developing toner according to <10> or <11>, wherein the total content of the low-molecular-weight siloxane is 0.01 ppm or more and 10 ppm or less based on the weight of the electrostatic image developing toner.
<13> The difference (ΔSP value) between the solubility parameter (SP value) of the crystalline polyester resin and the solubility parameter (SP value) of the amorphous resin satisfies the range of 0.1 or more and 1.2 or less. 1> to <12>, the electrostatic image developing toner.
<14> An electrostatic charge image developer containing the electrostatic charge image developing toner according to any one of <1> to <13>.
<15> A toner cartridge that contains the toner for developing an electrostatic charge image according to any one of <1> to <13> and is attachable to and detachable from an image forming apparatus.
<16> A developing unit containing the electrostatic charge image developer according to <14> and developing the electrostatic charge image formed on the surface of the image carrier by the electrostatic charge image developer as a toner image, A process cartridge that is attached to and detached from a forming apparatus.
<17> an image carrier, charging means for charging the surface of the image carrier, electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier, and the electrostatic charge according to <14>. developing means for accommodating a charge image developer and developing the electrostatic charge image formed on the surface of the image carrier by the electrostatic charge image developer into a toner image; and the toner formed on the surface of the image carrier. An image forming apparatus comprising: transfer means for transferring an image onto the surface of a recording medium; and fixing means for fixing the toner image transferred onto the surface of the recording medium.
<18> A charging step of charging the surface of the image carrier, an electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier, and the electrostatic charge image developer according to <14>, a developing step of developing an electrostatic charge image formed on the surface of the image carrier into a toner image; a transfer step of transferring the toner image formed on the surface of the image carrier onto a surface of a recording medium; and a fixing step of fixing the toner image transferred to the surface of the image forming method.

According to the invention relating to <1>, toner particles containing an amorphous resin and a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms; and an external additive, in the case where the external additive contains only silica particles having a BET specific surface area of less than 100 m ² /g, or in differential scanning calorimetry in accordance with ASTM D3418-8 , the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first temperature rising process is ΔH1 (mW / g), the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the second temperature rising process When the amount of heat is ΔH2 (mW/g), the detachment of the external additive from the toner particles is suppressed as compared with the case where the formula: 0.05>ΔH2/ΔH1 or the formula: ΔH2/ΔH1>0.95 is satisfied. A toner for developing electrostatic charge images is provided.

According to the invention relating to <2>, there is provided a toner for electrostatic charge image development that suppresses contamination of the toner cartridge as compared with the case where the formula: 0.35≧ΔH2/ΔH1 is satisfied.
According to the invention relating to <3>, there is provided a toner for electrostatic charge image development that suppresses contamination of the toner cartridge as compared with the case where the formula: 0.45≧ΔH2/ΔH1 is satisfied.

According to the invention relating to <4>, there is provided a toner for electrostatic charge image development that suppresses deterioration in transferability in a high-temperature and high-humidity environment as compared with the case where the formula: ΔH2/ΔH1>0.35 is satisfied.
According to the invention relating to <5>, there is provided a toner for electrostatic charge image development that suppresses deterioration in transferability in a high-temperature, high-humidity environment as compared with the case where the formula: ΔH2/ΔH1≧0.25 is satisfied.

According to the invention relating to <6>, there is provided a toner for developing an electrostatic charge image which further suppresses separation of the external additive from the toner particles as compared with the case where the average primary particle diameter of the silica particles exceeds 90 nm.
According to the invention according to <7>, there is provided a toner for electrostatic charge image development that further suppresses separation of the external additive from the toner particles as compared with the case where the silica particles are dry silica particles.
According to the invention relating to <8>, there is provided a toner for electrostatic charge image development that suppresses deterioration in transferability under a high-temperature and high-humidity environment as compared with the case where the coverage of the external additive is less than 80%.
According to the invention relating to <9>, aggregation of toner particles is suppressed compared to the case where the fluidity index of the electrostatic charge image developing toner stored for 24 hours in an environment of temperature 50° C. and humidity 50% exceeds 20. An electrostatic charge image developing toner is provided.

According to the invention according to <10> or <11>, the external additive is further removed from the toner particles compared to the case where the low-molecular-weight siloxane having a molecular weight of 200 or more and 600 or less, which is composed only of siloxane bonds and alkyl groups, is not included. Provided is a toner for developing an electrostatic charge image that suppresses the
According to the invention according to <12>, the external additive is further removed from the toner particles as compared with the case where the total content of the low-molecular-weight siloxane is less than 0.01 ppm with respect to the mass of the toner for developing an electrostatic charge image. Provided is a toner for developing an electrostatic charge image that suppresses the
According to the invention according to <13>, the difference (ΔSP value) between the solubility parameter (SP value) of the crystalline polyester resin and the solubility parameter (SP value) of the amorphous resin is less than 0.1 or 1.2. Provided is a toner for electrostatic charge image development that further suppresses separation of the external additive from the toner particles as compared with the case of exceeding.

According to the invention according to <14>, toner particles containing an amorphous resin and a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms; An electrostatic image developing toner containing an external additive, wherein the external additive contains only silica particles having a BET specific surface area of less than 100 m ² /g, or an electrostatic image developing toner conforming to ASTM D3418-8 In differential scanning calorimetry, the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first heating process is ΔH1 (mW / g), and the crystalline polyester resin derived heat in the second heating process is When the amount of heat absorbed based on the endothermic peak is ΔH2 (mW/g), the toner particles are smaller than the toner for electrostatic image development that satisfies the formula: 0.05>ΔH2/ΔH1 or the formula: ΔH2/ΔH1>0.95. Provided is an electrostatic charge image developer containing a toner for electrostatic charge image development that suppresses detachment of an external additive from the developer.

According to the invention according to <15>, toner particles containing an amorphous resin and a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms; An electrostatic image developing toner containing an external additive, wherein the external additive contains only silica particles having a BET specific surface area of less than 100 m ² /g, or an electrostatic image developing toner in accordance with ASTM D3418-8 In differential scanning calorimetry, the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first heating process is ΔH1 (mW / g), and the crystalline polyester resin derived heat in the second heating process is When the amount of heat absorbed based on the endothermic peak is ΔH2 (mW/g), the toner particles are more dense than the toner for electrostatic image development that satisfies the formula: 0.05>ΔH2/ΔH1 or the formula: ΔH2/ΔH1>0.95. Provided is a toner cartridge containing toner for electrostatic charge image development that suppresses detachment of an external additive from a toner cartridge.

According to the invention according to <16>, toner particles containing an amorphous resin and a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms; An electrostatic image developing toner containing an external additive, wherein the external additive contains only silica particles having a BET specific surface area of less than 100 m ² /g, or an electrostatic image developing toner conforming to ASTM D3418-8 In differential scanning calorimetry, the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first heating process is ΔH1 (mW / g), and the crystalline polyester resin derived heat in the second heating process is When the amount of heat absorbed based on the endothermic peak is ΔH2 (mW/g), the toner particles are smaller than the toner for electrostatic image development that satisfies the formula: 0.05>ΔH2/ΔH1 or the formula: ΔH2/ΔH1>0.95. Provided is a process cartridge to which an electrostatic charge image developer containing a toner for electrostatic charge image development that suppresses detachment of an external additive from the cartridge is applied.

According to the invention according to <17>, toner particles containing an amorphous resin and a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms; An electrostatic image developing toner containing an external additive, wherein the external additive contains only silica particles having a BET specific surface area of less than 100 m ² /g, or an electrostatic image developing toner conforming to ASTM D3418-8 In differential scanning calorimetry, the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first heating process is ΔH1 (mW / g), and the crystalline polyester resin derived heat in the second heating process is When the amount of heat absorbed based on the endothermic peak is ΔH2 (mW/g), the toner particles are smaller than the toner for electrostatic image development that satisfies the formula: 0.05>ΔH2/ΔH1 or the formula: ΔH2/ΔH1>0.95. Provided is an image forming apparatus using an electrostatic charge image developer containing a toner for electrostatic charge image development that suppresses detachment of an external additive from the developer.

According to the invention according to <18>, toner particles containing an amorphous resin and a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms; An electrostatic image developing toner containing an external additive, wherein the external additive contains only silica particles having a BET specific surface area of less than 100 m ² /g, or an electrostatic image developing toner conforming to ASTM D3418-8 In differential scanning calorimetry, the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first heating process is ΔH1 (mW / g), and the crystalline polyester resin derived heat in the second heating process is When the amount of heat absorbed based on the endothermic peak is ΔH2 (mW/g), the toner particles are smaller than the toner for electrostatic image development that satisfies the formula: 0.05>ΔH2/ΔH1 or the formula: ΔH2/ΔH1>0.95. Provided is an image forming method using an electrostatic charge image developer containing a toner for electrostatic charge image development that suppresses detachment of an external additive from the developer.

1 is a schematic configuration diagram showing an example of an image forming apparatus according to an embodiment; FIG. 1 is a schematic configuration diagram showing an example of a process cartridge detachable from an image forming apparatus according to an exemplary embodiment; FIG.

An embodiment that is an example of the present invention will be described below. These descriptions and examples are illustrative of embodiments and do not limit the scope of embodiments.

In this specification, the numerical range indicated using "to" indicates the range including the numerical values before and after "to" as the minimum and maximum values, respectively.

In the numerical ranges described stepwise in this specification, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of the numerical range described in other steps. good. Moreover, in the numerical ranges described in this specification, the upper and lower limits of the numerical ranges may be replaced with the values shown in the examples.

As used herein, the term "process" includes not only an independent process but also other processes as long as the intended purpose of the process is achieved even if it is not clearly distinguished from other processes. .

When embodiments are described herein with reference to the drawings, the configurations of the embodiments are not limited to the configurations shown in the drawings. In addition, the sizes of the members in each drawing are conceptual, and the relative relationship between the sizes of the members is not limited to this.

In the present specification, each component may contain multiple types of corresponding substances. When referring to the amount of each component in the composition in this specification, if there are multiple types of substances corresponding to each component in the composition, unless otherwise specified, the multiple types present in the composition means the total amount of substances in

Particles corresponding to each component in the present specification may contain a plurality of types. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means a value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

In this specification, the "toner for electrostatic charge image development" may be simply referred to as "toner", and the "electrostatic charge image developer" may be simply referred to as "developer".

<Toner for electrostatic charge image development>
The toner according to the present embodiment is a crystalline polyester resin (hereinafter also referred to as “specific crystalline polyester resin”) composed of a polycondensate of an amorphous resin, a linear dicarboxylic acid, and a linear dialcohol having 2 to 12 carbon atoms. and an external additive containing silica particles having a BET specific surface area of 100 m ² /g or more (hereinafter also referred to as “specific silica particles”), ASTM D3418-8 (2008) In differential scanning calorimetry according to , the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first heating process is ΔH1 (mW / g), and the crystalline polyester in the second heating process When the endothermic amount based on the endothermic peak derived from the resin is ΔH2 (mW/g), the formula: 0.05≦ΔH2/ΔH1≦0.95 is satisfied.
Hereinafter, the value of ΔH2/ΔH1 is also referred to as “ΔH2/ΔH1 value”.

Compared to the case where the external additive contains only silica particles having a BET specific surface area of less than 100 m ² /g, or the case where the ΔH2/ΔH1 value is less than 0.05 or exceeds 0.95, the toner according to the present embodiment has , the detachment of the external additive from the toner particles is suppressed. Although the reason is not clear, it is presumed as follows.

When silica particles are used as an external additive, the non-electrostatic adhesion force is dominant as the force with which the silica particles adhere to the toner particle surfaces, and the toner particles and silica particles electrostatically repel each other. It is thought that Therefore, for example, during agitation in the cartridge, the silica particles that are electrostatically repelled may separate from the toner particle surfaces.

On the other hand, in the present embodiment, specific silica particles are used as the silica particles, toner particles containing an amorphous resin and a specific crystalline polyester resin are used as the toner particles, and the ΔH2/ΔH1 value is 0.05 or more and 0.95 or less. be.
The specific silica particles are more likely to adsorb moisture than silica particles having a BET specific surface area of less than 100 m ² /g, and retain an appropriate amount of moisture on their surfaces. Further, in toner particles containing an amorphous resin and a specific crystalline polyester resin and having a ΔH2/ΔH1 value within the above range, the amorphous resin and the specific crystalline polyester resin are appropriately compatible. Then, the toner particles and the specific silica particles are externally added to the surfaces of the toner particles in which the amorphous resin and the specific crystalline polyester resin are appropriately compatible with each other, and the specific silica particles having an appropriate amount of moisture retained on the surfaces thereof. It is presumed that the electrostatic repulsion between and is suppressed, and detachment of the external additive containing the specific silica particles is suppressed.

Here, ΔH1 and ΔH2 are obtained for the toner to be measured in accordance with ASTM D3418-8 (2008) as follows. The crystalline resin refers to a resin having a distinct endothermic peak instead of a stepwise endothermic change in differential scanning calorimetry (DSC) according to ASTM D3418-8 (2008).
First, 10 mg of toner to be measured was set in a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-60A) equipped with an automatic tangent processing system, and the temperature was raised from room temperature (25° C.) to 150° C. at a rate of 10° C./min. and maintained at 150° C. for 5 minutes to obtain a heating spectrum (DSC curve) in the first heating process.
Subsequently, using liquid nitrogen, the temperature is lowered to 0°C at a cooling rate of -10°C/min, and the temperature is maintained at 0°C for 5 minutes.
After that, it is heated up to 150° C. at a rate of temperature increase of 10° C./min to obtain a temperature increase spectrum (DSC curve) in the second temperature increase process.

An endothermic peak derived from a specific crystalline polyester resin is identified from the two temperature-rising spectra (DSC curves) obtained. Specifically, an endothermic peak existing in the vicinity of the same temperature is determined as an endothermic peak derived from the crystalline resin by comparing with a previously measured DSC chart of the crystalline resin alone. Here, the endothermic peak has a half width of 15°C or less.
Then, for each temperature rise spectrum, the area of the endothermic peak derived from the specific crystalline polyester resin is calculated as the endothermic amount. The area of the endothermic peak is the area of the region surrounded by the endothermic peak and the baseline based on ASTM D3418-8 (2008) from the endothermic peak derived from the specific crystalline polyester resin. Then, the endothermic amount derived from the specific crystalline polyester resin is calculated by determining the endothermic amount per mass of the sample from the area of each endothermic peak.

-First aspect-
Among the present embodiments, in an embodiment in which the ΔH2/ΔH1 value is greater than 0.35 and equal to or less than 0.95 (hereinafter also referred to as “first embodiment”), separation of the external additive from the toner particles is further suppressed. As a result, the detached external additive is prevented from adhering to the wall surface of the toner cartridge.
2. Description of the Related Art In recent years, from the viewpoint of cost reduction and toner dischargeability, a rotary toner cartridge has been used that conveys toner by rotating the toner cartridge itself without a conveying member. In a rotary toner cartridge that does not have a conveying member, when the external additive is detached from the toner particles, the detached external additive tends to adhere to the wall surface of the toner cartridge. In particular, when the environment changes from high temperature and high humidity (e.g. temperature 28°C, humidity 85%) to low temperature low humidity (e.g. temperature 22°C, humidity 15%), condensation forms on the walls inside the cartridge, and the external additives adhering to the walls are removed. It may become sticky. Further, in the case of using a cartridge in which the toner inside is visible using a transparent or translucent container from the viewpoint of misuse prevention, etc., if the external additive adhering to the wall surface adheres, it may lead to misuse.

On the other hand, if the toner of the first aspect is used, the detachment of the external additive from the toner particles is further suppressed, so that the detached external additive is also suppressed from adhering to the wall surface of the toner cartridge.
Although the reason why the separation of the external additive from the toner particles is further suppressed in the first aspect is not clear, it is presumed as follows.
As described above, the specific silica particles used in the first aspect easily adsorb moisture and retain an appropriate amount of moisture on their surfaces. Further, the toner particles containing an amorphous resin and a specific crystalline polyester resin and having a ΔH2/ΔH1 value of more than 0.35 and 0.95 or less have the amorphous resin and the specific crystalline polyester resin on the surfaces of the toner particles. is partially compatible with each other. This moderate compatibility allows the component of the specific crystalline polyester resin to be dispersed over the entire surface of the toner particles, thereby facilitating the formation of charge paths (hereinafter also referred to as “conductive paths”) on the surfaces of the toner particles. The appropriate amount of moisture retained on the surface of the specific silica particles and the conductive paths formed on the surfaces of the toner particles further suppress the electrostatic repulsion between the toner particles and the silica particles, It is presumed that it will be more difficult to leave.

- Second aspect -
Among the present exemplary embodiments, in an aspect in which the ΔH2/ΔH1 value is 0.05 or more and 0.35 or less (hereinafter also referred to as a “second aspect”), uneven distribution of the external additive adhering to the surface of the toner particles is suppressed. In addition, since the detachment of the external additive from the toner particles is suppressed, deterioration in transferability in an environment of high temperature and high humidity (for example, temperature of 28° C. and humidity of 85%) is suppressed.
2. Description of the Related Art In recent years, there has been a demand for forming images using toners of various colors on various recording media. In particular, when multiple-color toner images are transferred onto a recording medium with a large surface unevenness such as embossed paper in a high-temperature and high-humidity environment, the use of toner with unevenly distributed external additives causes toner adhesion due to surface exposure of toner particles. The increase may lead to a decrease in transferability, resulting in image defects (color loss) due to poor transfer. On the other hand, when the toner of the second aspect is used, uneven distribution of the external additive adhering to the surface of the toner particles is suppressed, and detachment of the external additive from the toner particles is suppressed. Surface exposure is suppressed, and deterioration in transferability due to surface exposure of toner particles is suppressed even in a high-temperature and high-humidity environment.

In the second aspect, the reason why the uneven distribution of the external additive adhering to the surface of the toner particles is suppressed and the detachment of the external additive from the toner particles is suppressed is not clear, but is presumed as follows. be.
Toner particles containing an amorphous resin and a specific crystalline polyester resin and having a ΔH2/ΔH1 value of 0.05 or more and 0.35 or less have nearly uniform incompatible portions of the specific crystalline polyester resin on the surfaces of the toner particles. are considered to be dispersed in the state. Here, the non-compatible portion of the specific crystalline polyester resin has a lower resistance than that of the amorphous resin, and thus has a weak electrostatic adhesive force due to charge leakage, making it difficult for the external additive to adhere. Therefore, if the incompatible portion of the specific crystalline polyester resin is unevenly distributed on the surface of the toner particles, the surfaces of the toner particles are likely to be exposed. On the other hand, in the second aspect, as described above, the incompatible portion of the specific crystalline polyester resin on the surface of the toner particles is dispersed in a nearly uniform state, so that the It is presumed that uneven distribution of the external additive is suppressed.
In addition, the specific silica particles used in the second aspect easily adsorb water as described above, and have an appropriate amount of water on their surfaces, so that electrostatic repulsion between the toner particles and the silica particles It is presumed that the force is suppressed and the external additive is less likely to separate from the surface of the toner particles.
From the above, it is presumed that in the second aspect, uneven distribution of the external additive adhering to the surface of the toner particles is suppressed, and detachment of the external additive from the toner particles is suppressed.

Details of the toner according to the exemplary embodiment will be described below.

The toner according to this embodiment includes toner particles and an external additive.

(toner particles)
The toner particles contain, for example, a binder resin, and if necessary, a colorant, a release agent, and other additives.

- Binder resin -
The toner particles contain, as a binder resin, an amorphous resin and a crystalline polyester resin (i.e., a specific crystalline polyester resin ) and at least.

In addition, the “crystallinity” of the resin refers to having a clear endothermic peak instead of a stepwise endothermic change in differential scanning calorimetry (DSC). /min), the half width of the endothermic peak is within 15°C.
On the other hand, the “amorphous” resin means that the half width exceeds 15° C., shows a stepwise change in endothermic amount, or shows no clear endothermic peak.

The binder resin may contain other resins as needed. However, the total content of the amorphous resin and the specific crystalline polyester resin is preferably 80% by mass or more, more preferably 90% by mass or more, with respect to the total resin contained in the toner particles. % by mass or more is more preferable.

The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and 60% by mass or more and 85% by mass or less with respect to the entire toner particles. More preferred.

--Amorphous resin--
Examples of amorphous resins include styrenes (e.g., styrene, parachlorostyrene, α-methylstyrene), (meth)acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic n-butyl acid, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g. acrylonitrile) , methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (e.g., ethylene, propylene, butadiene, etc.) or a copolymer of two or more of these monomers in combination.
Examples of amorphous resins include epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, non-vinyl resins such as modified rosin, mixtures of these with the vinyl resins, or these. and a graft polymer obtained by polymerizing a vinyl-based monomer in the presence of.
These amorphous resins may be used singly or in combination of two or more.

A polyester resin is suitable as the amorphous resin.
Examples of polyester resins include known amorphous polyester resins.

- Amorphous Polyester Resin Examples of amorphous polyester resins include condensation polymers of polyhydric carboxylic acids and polyhydric alcohols. As the amorphous polyester resin, a commercially available product or a synthesized product may be used.

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

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

The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50°C or higher and 80°C or lower, more preferably 50°C or higher and 65°C or lower.
The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, described in JIS K 7121-1987 "Method for measuring the transition temperature of plastics" for determining the glass transition temperature. is determined by the "extrapolation glass transition start temperature" of

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably from 5,000 to 1,000,000, more preferably from 7,000 to 500,000, even more preferably from 9,000 to 100,000.
The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less.
The molecular weight distribution Mw/Mn of the amorphous polyester resin is preferably from 1.5 to 100, more preferably from 2 to 60.
The weight average molecular weight and number average molecular weight are measured by gel permeation chromatography (GPC). Molecular weight measurement by GPC is performed using Tosoh's GPC HLC-8120GPC as a measuring apparatus, using a Tosoh column TSKgel SuperHM-M (15 cm), and using THF solvent. The weight average molecular weight and number average molecular weight are calculated from these measurement results using a molecular weight calibration curve prepared from monodisperse polystyrene standard samples.

Amorphous polyester resins are obtained by well-known production methods. Specifically, for example, the polymerization temperature is adjusted to 180° C. or higher and 230° C. or lower, the pressure in the reaction system is reduced as necessary, and the reaction is performed while removing water and alcohol generated during condensation.
If the raw material monomers do not dissolve or are compatible with each other at the reaction temperature, a high-boiling solvent may be added as a dissolution aid to dissolve them. In this case, the polycondensation reaction is carried out while distilling off the solubilizing agent. If a monomer with poor compatibility is present, it is preferable to condense the monomer with poor compatibility, the monomer, and the acid or alcohol to be polycondensed in advance, and then polycondensate together with the main component. .

--Specific crystalline polyester resin--
The specific crystalline polyester resin consists of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 or more and 12 or less carbon atoms. That is, the specific crystalline polyester resin is composed of a polycondensate containing at least a structural unit derived from a straight-chain dicarboxylic acid and a structural unit derived from a straight-chain dialcohol having 2 to 12 carbon atoms.
The specific crystalline polyester resin may contain at least a straight-chain dicarboxylic acid and a straight-chain dialcohol having 2 to 12 carbon atoms as monomer components, and may contain other monomer components as necessary. The total content of linear dicarboxylic acids and linear dialcohols having 2 to 12 carbon atoms contained as monomer components in the polycondensate is 80 mass with respect to all monomer components contained in the polycondensate. % or more, more preferably 90 mass % or more, and even more preferably 95 mass % or more.

Linear dicarboxylic acids include, for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12- Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid and 1,18-octadecanedicarboxylic acid can be mentioned.
Among these, straight-chain dicarboxylic acids having 3 to 15 carbon atoms are preferred, and straight-chain dicarboxylic acids having 5 to 12 carbon atoms are more preferred.
Linear dicarboxylic acids may be used singly or in combination of two or more.

Linear dialcohols having 2 to 12 carbon atoms include, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, Aliphatic diols such as 7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol and 1,12-dodecanediol are included.
The number of carbon atoms in the linear dialcohol is 2 or more and 12 or less, preferably 2 or more and 10 or less, from the viewpoint of obtaining an appropriate state of compatibility with the amorphous resin and an appropriate resistance difference with the amorphous resin. be.
Linear dialcohols may be used singly or in combination of two or more.

The melting temperature of the specific crystalline polyester resin is preferably 50° C. or higher and 100° C. or lower, more preferably 55° C. or higher and 90° C. or lower, and even more preferably 60° C. or higher and 85° C. or lower.
The melting temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), using the "melting peak temperature" described in JIS K7121-1987 "Method for measuring transition temperature of plastics".

The weight average molecular weight (Mw) of the specific crystalline polyester resin is preferably 6,000 or more and 35,000 or less, more preferably 7,000 or more and 15,000 or less.

The specific crystalline polyester resin can be obtained, for example, by a well-known production method like the amorphous polyester resin.

-Relationship between amorphous resin and specific crystalline polyester resin-
The content of the specific crystalline polyester resin with respect to the total amount of the amorphous resin and the specific crystalline polyester resin is 2% by mass or more and 40% by mass or less, and is 2% by mass or more from the viewpoint of low-temperature fixability and image storage stability. 20% by mass or less is preferable, and 4% by mass or more and 15% by mass or less is more preferable.

From the viewpoint of the dispersibility of the external additive on the toner surface and the suppression of charge leakage, the difference (ΔSP value) between the solubility parameter (SP value) of the crystalline polyester resin and the solubility parameter (SP value) of the amorphous resin is , preferably in the range of 0.1 to 1.2, more preferably in the range of 0.5 to 1.0.
Here, the solubility parameter (SP value) of each resin is a value calculated by the Fedors method (Polym. Eng. Sci., 14, 147 (1974)).
Regarding the solubility parameter (SP value) of the resin, for example, when the resin is a polyester resin and an ethylene oxide adduct of bisphenol A is used as the alcohol component, the ethylene oxide adduct is changed to a propylene oxide adduct. By doing so, the SP value of the obtained polyester resin can be lowered. Further, when the resin is a polyester resin and an aliphatic dicarboxylic acid such as sebacic acid is used as the dicarboxylic acid used as the acid component, the aliphatic dicarboxylic acid is converted to an aromatic dicarboxylic acid such as terephthalic acid. By changing it, you can conversely increase the SP value.
The SP value of the resin can also be measured by examining the solubility in a solvent with a known SP value. However, since the actual phenomenon of compatibility between resins is related to the interaction of both resins, it is not necessarily possible only by the magnitude of the SP value. In this embodiment, the SP value is calculated by the above method (that is, the Fedors method).

-coloring agent-
Examples of colorants include carbon black, chrome yellow, Hansa yellow, benzidine yellow, thren 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, Pyrazolone Red, Lithol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or acridine-based, xanthene-based, azo-based, benzoquinone-based, azine-based, anthraquinone-based, thioindico-based, dioxazine-based, thiazine-based, azomethine-based, indico-based, phthalocyanine-based, aniline black and polymethine-based, triphenylmethane-based, diphenylmethane-based, and thiazole-based dyes.
Colorants may be used singly or in combination of two or more.

As for the coloring agent, a surface-treated coloring agent may be used as necessary, and a dispersing agent may be used in combination. Also, a plurality of types of colorants may be used in combination.

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

-Release agent-
Release agents include, for example, 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 montan acid esters. ; and the like. 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, more preferably 60° C. or higher and 100° C. or lower.
The melting temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and is determined by the "melting peak temperature" described in the method for determining the melting temperature of JIS K 7121-1987 "Method for measuring the 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 5% by mass or more and 15% by mass or less, relative to the entire toner particles.

-Other additives-
Other additives include, for example, well-known additives such as magnetic substances, charge control agents, and inorganic powders. These additives are contained in the toner particles as internal additives.

Further, as other additives (that is, internal additives), low-molecular-weight siloxanes (hereinafter also referred to as "low-molecular-weight siloxanes") having a molecular weight of 200 or more and 600 or less composed only of siloxane bonds and alkyl groups may be used. In particular, in the second aspect described above, the toner particles preferably contain low-molecular-weight siloxane as an internal additive.
By using the low-molecular-weight siloxane as the internal additive, the dispersibility of the incompatible portion of the specific crystalline polyester resin on the surface of the toner particles is improved, so that the uneven distribution of the external additive adhering to the surface of the toner particles is suppressed. be.
Details of the low-molecular-weight siloxane will be described later.

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

The volume average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less.

Various average particle diameters and various particle size distribution indices of toner particles were measured using Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) and the electrolytic solution using ISOTON-II (manufactured by Beckman Coulter, Inc.). be.
In the 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 was suspended was subjected to dispersion treatment for 1 minute with an ultrasonic disperser, and the particle size distribution of particles with a particle size in the range of 2 μm or more and 60 μm or less was measured with a Coulter Multisizer II using an aperture with an aperture diameter of 100 μm. Measure. Note that the number of particles to be sampled is 50,000.
Based on the measured particle size distribution, the volume and number of the particle size ranges (channels) divided based on the cumulative distribution are drawn from the small diameter side, and the particle size at which the cumulative 16% is the volume particle size D16v, the number particle size D16p, the particle diameter at which the cumulative 50% is obtained is defined as the volume average particle diameter D50v, the cumulative number average particle diameter D50p, the particle diameter at which the cumulative 84% is obtained is defined as the volume particle diameter D84v and the number particle diameter 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 0.94 or more and 1.00 or less, more preferably 0.95 or more and 0.98 or less.

The average circularity of toner particles is obtained by (equivalent circle perimeter)/(perimeter) [(perimeter of circle having the same projected area as the particle image)/(perimeter of projected particle image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Sysmex) collects the toner particles to be measured by suction, forms a flat flow, captures the particle image as a still image by instantaneously emitting strobe light, and analyzes the image of the particle image. FPIA-3000 manufactured by Co., Ltd.). Then, the number of samples for obtaining the average circularity is 3500.
When the toner contains an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then subjected to ultrasonic treatment to obtain toner particles from which the external additive is removed. .

(external additive)
The external additive contains at least silica particles (that is, specific silica particles) having a BET specific surface area of 100 m ² /g or more, and may contain other external additives as necessary.
The content of the specific silica particles in the total external additive is, for example, 10% by mass or more, preferably 20% by mass or more and 80% by mass or less, and more preferably 25% by mass or more and 60% by mass or less.

- Specific silica particles -
The specific silica particles are not particularly limited as long as they are silica particles having a BET specific surface area of 100 m ² /g or more.
The BET specific surface area of the specific silica particles is preferably 100 m ² /g or more and 240 m ² /g or less, more preferably 120 m ² /g or more and 220 m ² /g or less, and 120 m ² /g from the viewpoint of suppressing the separation of the external additive. More preferably, it is 180 m ² /g or more.

The BET specific surface area of the specific silica particles is measured by the BET multipoint method using nitrogen gas.
The sample to be measured is the specific silica particles that are the material of the toner, or the specific silica particles that are separated from the toner. The method for separating the specific silica particles from the toner is not limited. For example, after applying ultrasonic waves to a dispersion liquid in which the toner is dispersed in water containing a surfactant, the dispersion liquid is centrifuged at high speed, and the supernatant liquid is cooled to room temperature ( 23° C.±2° C.) to obtain specific silica particles.

The average primary particle size of the specific silica particles is preferably 20 nm or more and 90 nm or less.
When the average primary particle diameter of the specific silica particles is 20 nm or more, the silica particles are less likely to be embedded in the toner particles. From this point of view, the average primary particle size of the sol-gel silica particles is more preferably 25 nm or more, and even more preferably 30 nm or more.
When the average primary particle size of the specific silica particles is 90 nm or less, the electrostatic repulsion to the toner particles is suppressed, and the silica particles tend to stay on the surface of the toner particles. From this point of view, the average primary particle size of the specific silica particles is more preferably 85 nm or less, even more preferably 80 nm or less.

In the present embodiment, the primary particle size of the specific silica particles is the diameter of a circle having the same area as the primary particle image (so-called circle equivalent diameter), and an electron microscope image of the toner to which the specific silica particles are externally added is taken. , is obtained by image analysis of at least 300 specific silica particles on the toner particles. The average primary particle size of the specific silica particles is the particle size that is cumulatively 50% from the small size side in the number-based distribution of the primary particle sizes.

The specific silica particles preferably have a mass reduction rate of 1% by mass or more and 10% by mass or less when heated from 30° C. to 250° C. at a heating rate of 30° C./min. In addition, the mass reduction ratio indicates the amount of water contained in the specific silica particles.
When the mass reduction rate is 1% by mass or more, an appropriate amount of water is retained on the surface of the specific silica particles, so that the electrostatic repulsive force between the toner particles and the specific silica particles is suppressed. It becomes difficult for silica particles to separate. From this point of view, the mass reduction rate is more preferably 2% by mass or more, and even more preferably 3% by mass or more.
When the weight reduction ratio is 10% by weight or less, the silica particles are less likely to be unevenly distributed on the surface of the toner, resulting in good dispersibility. From this point of view, the mass reduction rate is more preferably 9% by mass or less, and even more preferably 8% by mass or less.

In the present embodiment, the mass reduction ratio when the specific silica particles are heated is obtained by the following measuring method.
30 mg of specific silica particles are placed in the sample chamber of a micro thermogravimetry device (manufactured by Shimadzu Corporation, model number DTG-60AH), heated from 30 ° C. to 250 ° C. at a heating rate of 30 ° C./min, and the initial mass Calculate the mass reduction rate from the difference between.
The sample to be subjected to the micro-thermogravimetry is the specific silica particles that are the material of the toner or the specific silica particles separated from the toner. The method for separating the specific silica particles from the toner is not limited. For example, after applying ultrasonic waves to a dispersion liquid in which the toner is dispersed in water containing a surfactant, the dispersion liquid is centrifuged at high speed, and the supernatant liquid is cooled to room temperature ( 23° C.±2° C.) to obtain specific silica particles.

Specific silica particles include, for example, sol-gel silica particles.
Sol-gel silica particles are obtained, for example, as follows.
Tetraalkoxysilane is added dropwise to an alkaline catalyst solution containing an alcohol compound and aqueous ammonia to hydrolyze and condense the tetraalkoxysilane to obtain a suspension containing sol-gel silica particles. The solvent is then removed from the suspension to obtain granules. The sol-gel silica particles are then obtained by drying the granules.
The average primary particle size of the sol-gel silica particles is controlled by the amount of tetraalkoxysilane added relative to the amount of the alkaline catalyst solution.
Also, the BET specific surface area of the sol-gel silica particles is controlled by the hydrophobizing treatment conditions, the abundance ratio of water and methanol contained in the particles, and the like.
In addition, the amount of water contained in the sol-gel silica particles, that is, the mass reduction rate when heated from 30° C. to 250° C. at a temperature increase rate of 30° C./min is controlled by the drying conditions when drying the granular material. .

The sol-gel silica particles may be hydrophobic sol-gel silica particles that have undergone a hydrophobizing surface treatment. The hydrophobizing agent is not particularly limited, but silicon-containing organic compounds are preferred. Silicon-containing organic compounds include alkoxysilane compounds, silazane compounds, and silicone oils. These may be used individually by 1 type, and may use 2 or more types together.

Silazane compounds (e.g., dimethyldisilazane, trimethyldisilazane, tetramethyldisilazane, pentamethyldisilazane, hexamethyldisilazane, etc.) are preferred as hydrophobizing agents for sol-gel silica particles. ,3,3-hexamethyldisilazane (HMDS) is particularly preferred.

Even when the sol-gel silica particles are hydrophobic sol-gel silica particles subjected to a hydrophobizing surface treatment, the mass reduction rate upon heating is preferably within the aforementioned range, and the average primary particle diameter is preferably within the aforementioned range.

The amount of the specific silica particles externally added is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.05% by mass or more and 5% by mass or less, and 0.1% by mass or more, relative to the mass of the toner particles. 2.5% by mass or less is more preferable.

-Other external additives-
Other external additives include, for example, inorganic particles other than the specific silica 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 other than the specific silica particles , 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 used as other external additives is preferably subjected to a hydrophobizing treatment. 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 silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used individually by 1 type, and may use 2 or more types together.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

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

As other external additives, among these, silica particles other than the specific silica particles (that is, silica particles having a BET specific surface area of less than 100 m ² /g) are preferable. By using silica particles other than the specific silica particles as the other external additive, it is possible to suppress deterioration of the charging performance when the released external additive contaminates the carrier. As a result, detachment of the external additive is suppressed when subjected to mechanical stress in the developing machine for a long period of time, and a high-quality image with excellent transferability in a high-temperature, high-humidity environment can be provided for a long period of time.
The total content of the specific silica particles and other than the specific silica particles is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, relative to the total amount of the external additive. be.

-About all external additives-
A low-molecular-weight siloxane having a molecular weight of 200 or more and 600 or less (that is, low-molecular-weight siloxane) composed only of siloxane bonds and alkyl groups may adhere to the surface of the external additive. In particular, in the first aspect described above, it is preferable that low-molecular-weight siloxane adheres to the surface of the external additive. When the external additive contains specific silica particles and other external additives, low-molecular-weight siloxane may adhere to the surface of the specific silica particles, and low-molecular-weight siloxane may adhere to the surface of the other external additive. , the low-molecular-weight siloxane may adhere to both the specific silica particles and other external additives.
Since the low-molecular-weight siloxane adheres to the surface of the external additive, the electrostatic repulsion between the toner particles and the external additive is further suppressed, and detachment of the external additive is suppressed.
When the external additive is the hydrophobic sol-gel silica particles that have been subjected to the above-described hydrophobizing surface treatment, the low-molecular-weight siloxane is preferably attached to the surfaces of the sol-gel silica particles that have been subjected to the hydrophobizing treatment. .
Details of the low-molecular-weight siloxane will be described later.

The total external addition amount of the external additive is, for example, preferably 0.01% by mass or more and 5% by mass or less, more preferably 1.0% by mass or more and 4.0% by mass or less, relative to the toner particles.

The total content of external additives contained in the toner is determined by the following measuring method.
After ultrasonic waves are applied to a dispersion of toner in water containing a surfactant, the dispersion is centrifuged at high speed, and the supernatant is dried at normal temperature (23° C.±2° C.) to obtain an external additive. and weigh the external additive obtained from the supernatant. Here, although low-molecular-weight siloxane may adhere to the surface of the external additive obtained from the supernatant liquid, the amount of adhering low-molecular-weight siloxane is very small compared to the external additive, so it is ignored.

(low molecular weight siloxane)
The toner may, if necessary, contain low-molecular-weight siloxane (that is, low-molecular-weight siloxane) having a molecular weight of 200 or more and 600 or less composed only of siloxane bonds and alkyl groups.
As used herein, siloxane refers to a compound composed only of siloxane bonds and alkyl groups, unless otherwise specified. In addition, in this specification, siloxane having a molecular weight of 1000 or more is referred to as silicone oil.
For example, the low-molecular-weight siloxane may be contained inside the toner particles as an internal additive, or may be contained in a state attached to the surface of the external additive, and may be contained inside the toner particles and on the surface of the external additive. may be included in both

The molecular weight of the low-molecular-weight siloxane is 200 or more, preferably 250 or more, more preferably 280 or more, even more preferably 300 or more. The molecular weight of the low-molecular-weight siloxane is 600 or less, preferably 550 or less, more preferably 500 or less, and even more preferably 450 or less.
When a low-molecular-weight siloxane is used as an internal additive, the molecular weight of the low-molecular-weight siloxane within the above range has the advantage that the dispersibility of the incompatible portion is better than when the molecular weight is smaller than the above range. There is an advantage that the uniform dispersibility in the toner is improved as compared with the case where it is larger than the range.
When the low-molecular-weight siloxane is attached to the surface of the external additive and used, the molecular weight of the low-molecular-weight siloxane within the above range has the advantage of suppressing aggregation of siloxane compared to the case where the molecular weight is smaller than the above range. There is an advantage that the electrostatic repulsion of the silica particles can be suppressed as compared with the case where it is larger than the above range.

The low-molecular-weight siloxane has at least two Si atoms in one molecule.
From the viewpoint of suppressing electrostatic repulsion between the toner particles and the external additive, the low-molecular-weight siloxane preferably has 3 or more Si atoms in one molecule, and 4 or more Si atoms. is more preferable, and 5 or more is even more preferable.
From the viewpoint of suppressing electrostatic repulsion between the toner particles and the external additive, the low-molecular-weight siloxane preferably has 7 or less, more preferably 6 or less, Si atoms in one molecule. is more preferable, and 5 or less is even more preferable.
From both of the above viewpoints, it is particularly preferable that the number of Si atoms in one molecule of the low-molecular-weight siloxane is 5.

The kinematic viscosity of the low-molecular-weight siloxane at 25° C. is preferably 2 mm ² /s or more and 5 mm ² /s or less from the viewpoint of the dispersibility of the siloxane in the toner and the external additive.
In the present embodiment, the kinematic viscosity (mm ² /s) of siloxane is the value obtained by dividing the viscosity at 25° C. measured using an Ostwald viscometer, which is a kind of capillary viscometer, by the density.

An example of the low-molecular-weight siloxane is linear low-molecular-weight siloxane with unbranched siloxane bonds (hereinafter also referred to as “low-molecular-weight linear siloxane”).
Low-molecular linear siloxanes include, for example, hexaalkyldisiloxane, octaalkyltrisiloxane, decaalkyltetrasiloxane, dodecaalkylpentasiloxane, tetradecaalkylhexasiloxane, and hexadecaalkylheptasiloxane (where the molecular weight is 200 or more and 600 or less).
The alkyl group possessed by these low-molecular-weight linear siloxanes includes, for example, 1 to 10 carbon atoms (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, more preferably 1 or 2 carbon atoms ), a branched alkyl group having 3 to 10 carbon atoms (preferably 3 to 6 carbon atoms, more preferably 3 or 4 carbon atoms), 3 to 10 carbon atoms (preferably A cyclic alkyl group having 3 or more and 6 or less, more preferably 3 or 4) carbon atoms can be mentioned. Among them, an alkyl group having 1 to 3 carbon atoms is preferable, at least one of a methyl group and an ethyl group is preferable, and a methyl group is more preferable. A plurality of alkyl groups in one low-molecular weight linear siloxane molecule may be the same or different.

Specific examples of low-molecular linear siloxanes include octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, tetradecamethylhexasiloxane, and hexadecamethylheptasiloxane.

An example of the low-molecular-weight siloxane is a branched low-molecular-weight siloxane having branched siloxane bonds (hereinafter also referred to as "low-molecular-weight branched siloxane").
Examples of low molecular weight branched siloxanes include 1,1,1,3,5,5,5-heptaalkyl-3-(trialkylsiloxy)trisiloxane, tetrakis(trialkylsiloxy)silane, 1,1,1 , 3,5,5,7,7,7-nonaalkyl-3-(trialkylsiloxy)tetrasiloxane (with a molecular weight of 200 or more and 600 or less).
The alkyl group possessed by these low-molecular-weight branched siloxanes has, for example, 1 to 10 carbon atoms (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, still more preferably 1 or 2 carbon atoms). , a branched alkyl group having 3 to 10 carbon atoms (preferably 3 to 6 carbon atoms, more preferably 3 or 4 carbon atoms), 3 to 10 carbon atoms (preferably 3 carbon atoms A cyclic alkyl group having 6 or less carbon atoms, more preferably 3 or 4 carbon atoms, can be mentioned. Among them, an alkyl group having 1 to 3 carbon atoms is preferable, at least one of a methyl group and an ethyl group is preferable, and a methyl group is more preferable. A plurality of alkyl groups present in one molecule of the low-molecular-weight branched siloxane may be the same or different.

Specific examples _of low molecular weight branched siloxanes include methyltris(trimethylsiloxy ₎ silane ₍ molecular formula _C10H30O3Si4 ), tetrakis( _{trimethylsiloxy} )silane (molecular formula _{C12H36O4Si5 )} , _1,1 , 1,3,5,5,7,7,7-nonamethyl-3-(trimethylsiloxy)tetrasiloxane (molecular formula C ₁₂ H ₃₆ O ₄ Si ₅ ).

An example of the low-molecular-weight siloxane is a cyclic low-molecular-weight siloxane having a cyclic structure composed only of siloxane bonds (hereinafter also referred to as “low-molecular-weight cyclic siloxane”).
Examples of low molecular weight cyclic siloxanes include hexaalkylcyclotrisiloxane, octaalkylcyclotetrasiloxane, decaalkylcyclopentasiloxane, dodecaalkylcyclohexasiloxane, tetradecaalkylcycloheptasiloxane, and hexadecaalkylcyclooctasiloxane ( However, the molecular weight is 200 or more and 600 or less.).
Examples of alkyl groups possessed by these low-molecular-weight cyclic siloxanes include those having 1 to 10 carbon atoms (preferably 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, still more preferably 1 or 2 carbon atoms). Linear alkyl group, branched alkyl group having 3 to 10 carbon atoms (preferably 3 to 6 carbon atoms, more preferably 3 or 4 carbon atoms), 3 to 10 carbon atoms (preferably 3 or more carbon atoms) A cyclic alkyl group having 6 or less carbon atoms, more preferably 3 or 4 carbon atoms, can be mentioned. Among them, an alkyl group having 1 to 3 carbon atoms is preferable, at least one of a methyl group and an ethyl group is preferable, and a methyl group is more preferable. A plurality of alkyl groups present in one molecule of low-molecular-weight cyclic siloxane may be the same or different.

Specific examples of low-molecular-weight cyclic siloxanes include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, tetradecamethylcycloheptasiloxane, and hexadecamethylcyclooctasiloxane. .

The low-molecular-weight siloxane is preferably at least one selected from the group consisting of low-molecular-weight linear siloxanes and low-molecular-weight branched siloxanes, from the viewpoint of suppressing external additive separation and uneven distribution of external additives. Branched siloxanes are more preferred, and low-molecular-weight siloxanes having a tetrakis structure are even more preferred. A siloxane having a tetrakis structure refers to a siloxane having at least one of the following structures (that is, a tetrakissiloxysilane structure) in the molecule.

The low-molecular-weight siloxane having a tetrakis structure includes tetrakis(trialkylsiloxy)silane, where the alkyl group has, for example, 1 to 10 carbon atoms (preferably 1 to 6 carbon atoms, more preferably 1 to 6 carbon atoms). 1 or more and 3 or less, more preferably 1 or 2 carbon atoms) linear alkyl group, 3 or more and 10 or less carbon atoms (preferably 3 or more and 6 or less carbon atoms, more preferably 3 or 4 carbon atoms) branched Examples include an alkyl group and a cyclic alkyl group having 3 to 10 carbon atoms (preferably 3 to 6 carbon atoms, more preferably 3 or 4 carbon atoms). Among them, an alkyl group having 1 to 3 carbon atoms is preferable, at least one of a methyl group and an ethyl group is preferable, and a methyl group is more preferable. The alkyl groups in one molecule of low-molecular-weight siloxane having a tetrakis structure may be the same or different.

As the low-molecular-weight siloxane, tetrakis(trimethylsiloxy)silane is particularly preferable from the viewpoint of suppressing the separation of the external additive and suppressing the uneven distribution of the external additive.

The total content of the low-molecular-weight siloxane in the toner is preferably 0.01 ppm or more, more preferably 0, based on the mass of the toner, from the viewpoint of suppressing the separation of the external additive and suppressing the uneven distribution of the external additive. It is 0.05 ppm or more, more preferably 0.1 ppm or more.
The total content of low-molecular-weight siloxane contained in the toner is preferably 10 ppm or less, more preferably 5 ppm or less, relative to the mass of the toner, from the viewpoint of suppressing the separation of the external additive and suppressing the decrease in conductivity of the toner. more preferably 1 ppm or less, particularly preferably 0.5 ppm or less.
Note that "ppm" is an abbreviation for parts per million, and is based on mass.

The total content of low-molecular-weight siloxane contained in the toner was measured using a gas chromatograph mass spectrometer (manufactured by Shimadzu Corporation, GCMS-QP2020) and a non-polar column (manufactured by Restek, Rtx-1, 10157, film thickness 1.00 μm). , length 60 m, inner diameter 0.32 mm), and measured by the headspace method. A specific identification method is as follows.
The toner is weighed into a vial, the vial is capped and sealed, and heated to 190° C. for 3 minutes. Next, the volatile components in the vial are introduced into the column, and low-molecular-weight siloxane having a molecular weight of 200 or more and 600 or less is detected under the following conditions. The total amount of low-molecular-weight siloxane is calculated from the total area of peaks corresponding to low-molecular-weight siloxane and the calibration curve of the standard substance (Tetrakis (trimethylsiloxy) silane), and the total content of low-molecular-weight siloxane (ppm) relative to the total amount of toner. Calculate
・Carrier gas type: helium ・Carrier gas pressure: 120 kPa (constant pressure)
・Oven temperature: 40 ° C (5 minutes) → (15 ° C / min) → 250 ° C (6 minutes) (total 25 minutes)
・Ion source temperature: 260°C
・Interface temperature: 260℃

The total content of low-molecular-weight siloxanes contained in the toner is preferably 10 ppm or more, more preferably 15 ppm or more, relative to the total content of the external additives contained in the toner, from the viewpoint of suppressing the separation of the external additives. is more preferable, and 20 ppm or more is even more preferable.
The total content of low-molecular-weight siloxane contained in the toner is the total amount of the external additives contained in the toner, from the viewpoint of suppressing the separation of the crystalline polyester resin from the toner due to the extremely enhanced dispersibility of the incompatible portion. The content is preferably 1000 ppm or less, more preferably 500 ppm or less, even more preferably 200 ppm or less, and even more preferably 100 ppm or less.
The above mass ratio is a value obtained by converting {total content of low-molecular-weight siloxane contained in toner/total content of external additives contained in toner} into parts per million.

(Toner manufacturing method)
Next, a method for manufacturing the toner according to this embodiment will be described.
The toner according to the exemplary embodiment is obtained by externally adding an external additive to the toner particles after manufacturing the toner particles.

The toner particles may be produced by either a dry method (eg, kneading pulverization method, etc.) or a wet method (eg, aggregation coalescence method, suspension polymerization method, dissolution suspension method, etc.). The method for producing the toner particles is not particularly limited, and a well-known production method is employed.
Among these, it is preferable to obtain toner particles by the aggregation coalescence method.

Specifically, for example, when toner particles are produced by an aggregation coalescence method,
A step of preparing a resin particle dispersion in which resin particles to be a binder resin are dispersed (resin particle dispersion preparation step); dispersion), a step of aggregating resin particles (other particles as necessary) to form aggregated particles (aggregated particle forming step), and heating the aggregated particle dispersion in which the aggregated particles are dispersed. , and a step of fusing and uniting aggregated particles to form toner particles (fusing and uniting step), to produce toner particles.

Details of each step will be described below.
In the following description, a method for obtaining toner particles containing a colorant and a release agent will be described, but the colorant and release agent are used as necessary. Needless to say, additives other than colorants and release agents may be used.

-Resin particle dispersion preparation step-
First, together with a resin particle dispersion in which resin particles that serve as a binder resin are dispersed, for example, a colorant particle dispersion in which colorant particles are dispersed and a release agent particle dispersion in which release agent particles are dispersed are prepared. do.

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

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

Examples of surfactants include anionic surfactants such as sulfate-based, sulfonate-based, phosphate-based, and soap-based surfactants; cationic surfactants such as amine salt-type and quaternary ammonium salt-type; polyethylene glycol. nonionic surfactants such as surfactants, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly exemplified. Nonionic surfactants may be used in combination with anionic surfactants or cationic surfactants.
Surfactants may be used singly or in combination of two or more.

As a method for dispersing the resin particles in the dispersion medium in the resin particle dispersion, for example, general dispersing methods such as a rotary shearing homogenizer, a ball mill having media, a sand mill, and a dyno mill can be used. Also, depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion 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) for neutralization. By adding (W phase), the resin is converted from W/O to O/W (so-called phase inversion) to form a discontinuous 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 liquid is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and further preferably 0.1 μm or more and 0.6 μm or less. preferable.
The volume average particle diameter of the resin particles is determined using a particle size distribution obtained by measurement with a laser diffraction particle size distribution analyzer (for example, LA-700 manufactured by Horiba, Ltd.) with respect to the divided particle size range (channel). , the cumulative distribution of the volume is subtracted from the smaller particle size side, and the particle size at which 50% of the total particles are accumulated is measured as the volume average particle size D50v. The volume average particle diameter of particles in other dispersion liquids 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, more preferably 10% by mass or more and 40% by mass or less.

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

-Agglomerated particle formation step-
Next, the colorant particle dispersion and the release agent particle dispersion are mixed together with the resin particle dispersion.
Then, in the mixed dispersion, resin particles, colorant particles, and release agent particles are heteroaggregated to form resin particles, colorant particles, and 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 be acidic (for example, the pH is 2 or more and 5 or less), and if necessary, a dispersion stabilizer is added, The particles dispersed in the mixed dispersion are aggregated by heating to a temperature of the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles is −30° C. or more and the glass transition temperature is −10° C. or less). , to form agglomerated particles.
In the aggregated particle forming step, for example, the mixed dispersion is stirred with a rotary shear homogenizer, the flocculant is added at room temperature (for example, 25 ° C.), and the mixed dispersion is acidified (for example, pH is 2 or more and 5 or less). ) and, if necessary, after adding a dispersion stabilizer, the above heating may be performed.

The flocculant includes, for example, a surfactant having a polarity opposite to that of the surfactant used as the dispersant added to the mixed dispersion, an inorganic metal salt, and a divalent or higher metal complex. In particular, when a metal complex is used as the aggregating agent, the amount of surfactant used is reduced, and charging characteristics are improved.
Additives that form complexes or similar bonds with the metal ions of the flocculant may be used as needed. A chelating agent is preferably used as this additive.

Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic salts such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. metal salt polymers and the like.
A water-soluble chelating agent may be used as the chelating agent. Chelating agents include, for example, oxycarboxylic acids such as tartaric acid, citric acid and gluconic acid, iminodiacid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA) and the like.
The amount of the chelating agent to be added is, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, 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/union process－
Next, the aggregated particle dispersion in which the aggregated particles are dispersed is heated, for example, to a temperature higher than the glass transition temperature of the resin particles (for example, a temperature higher than the glass transition temperature of the resin particles by 10 to 30° C.) to obtain the aggregated particles. are fused and coalesced to form toner particles.

Toner particles are obtained through the above steps.
After obtaining the aggregated particle dispersion in which the aggregated particles are dispersed, the aggregated particle dispersion and the resin particle dispersion in which the resin particles are dispersed are further mixed to further add the resin particles to the surfaces of the aggregated particles. a step of forming second aggregated particles by aggregating them so as to adhere; heating the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and coalesce the second aggregated particles; , and a step of forming toner particles having a core/shell structure.

Here, after the fusion/coalescing 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 dried toner particles.
In the washing step, it is preferable to sufficiently perform displacement washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but from the viewpoint of productivity, suction filtration, pressure filtration, or the like may be performed. Also, the drying process is not particularly limited, but from the viewpoint of productivity, it is preferable to apply freeze drying, flash drying, fluidized drying, vibrating fluidized drying, and the like.

Then, the toner according to the exemplary embodiment is produced, for example, by adding an external additive to the obtained dry toner particles and mixing them. Mixing may be carried out using, for example, a V blender, a Henschel mixer, a Loedige mixer, or the like. Further, if necessary, a vibration sieving machine, an air sieving machine, or the like may be used to remove coarse toner particles.

(Characteristics of toner)
-ΔH2/ΔH1 value-
The ΔH2/ΔH1 value of the toner is, as described above, from 0.05 to 0.95, preferably from 0.08 to 0.95, more preferably from 0.10 to 0.80. It is preferably 0.12 or more and 0.80 or less.
In the first aspect, the ΔH2/ΔH1 value of the toner is greater than 0.35 and 0.95 or less, preferably 0.45 or more and 0.80 or less.
Furthermore, in the second aspect, the ΔH2/ΔH1 value of the toner is 0.05 or more and 0.35 or less, preferably 0.08 or more and 0.32 or less, and more preferably 0.10 or more and 0.30. or less, more preferably 0.12 or more and 0.28 or less, and particularly preferably 0.15 or more and less than 0.25.

When the ΔH2/ΔH1 value is greater than 0.35 and 0.95 or less, the crystalline resin is unevenly distributed in the toner as compared to when the ΔH2/ΔH1 value is greater than 0.95. means that Therefore, the toner having a ΔH2/ΔH1 value of more than 0.35 and 0.95 or less has a higher compatibility between the amorphous resin and the specific crystalline polyester resin than the toner having a ΔH2/ΔH1 value of more than 0.95. is not too high and a moderately compatible state is obtained, and fine incompatible portions of the specific crystalline polyester resin are dispersed on the surface of the toner particles. In addition, the non-compatible portion of the specific crystalline polyester resin dispersed on the surface of the toner particles facilitates the formation of a conductive path, thereby suppressing the electrostatic repulsion between the toner particles and the external additive. , the detachment of the external additive from the toner particles is suppressed.
Further, the toner with a ΔH2/ΔH1 value of greater than 0.35 has a higher compatibility between the amorphous resin and the specific crystalline polyester resin than the toner with a ΔH2/ΔH1 value of 0.35 or less, and has fine specific specificity. The incompatible portion of the crystalline polyester resin is dispersed on the surface of the toner particles, which facilitates the formation of conductive paths and suppresses the electrostatic repulsive force, thereby preventing the external additive from detaching from the toner particles. Suppressed.

A ΔH2/ΔH1 value of 0.05 or more means that there is a compatible portion between the amorphous resin and the specific crystalline polyester resin compared to the case where the ΔH2/ΔH1 value is less than 0.05. means Therefore, a toner having a ΔH2/ΔH1 value of 0.05 or more has higher compatibility between the amorphous resin and the specific crystalline polyester resin than a toner having a ΔH2/ΔH1 value of less than 0.05. As a result, the uneven distribution of the incompatible portion of the specific crystalline polyester resin on the surface of the toner particles is suppressed, and the embedding of the external additive in the incompatible portion of the specific crystalline polyester resin is suppressed. While the uneven distribution of the external additive adhering to the surface of the toner particles is suppressed, the electrostatic repulsive force is suppressed, thereby suppressing the detachment of the external additive from the toner particles.
Further, the toner having a ΔH2/ΔH1 value of 0.35 or less has too many compatible portions between the amorphous resin and the specific crystalline polyester resin compared to the toner having a ΔH2/ΔH1 value of more than 0.35. However, there is an advantage that the long-term storage stability is improved because the cohesiveness at room temperature (23° C.±2° C.) is less likely to deteriorate.

- Coverage of external additives -
The coverage of the external additive on the surface of the toner particles is preferably 80% or more, more preferably 83% or more, and even more preferably 85% or more.
When the coverage of the external additive is 80% or more, an increase in adhesion force due to exposure of the surface of the toner particles is suppressed, and deterioration in transferability due to an increase in adhesion force is suppressed.
In particular, by setting the coverage of the external additive to 80% or more and the particle diameter of the specific silica particles to 20 nm or more and 80 nm or less, the external additive is slightly detached while suppressing an increase in adhesion force due to the exposure of the toner particle surface. Even if the agent contaminates the carrier, deterioration in charging performance is suppressed. As a result, detachment of the external additive is suppressed when subjected to mechanical stress in the developing machine, and a high-quality image with excellent transferability in a high-temperature, high-humidity environment can be provided for a long period of time.

The coverage of the external additive is obtained by the following method.
(1) Toner is dispersed in an epoxy resin and allowed to stand for a whole day and night to solidify to prepare a measurement sample. As the epoxy resin, for example, a two-liquid mixed type epoxy resin may be used.
(2) Cut out a 100 nm-thick section from the measurement sample with a microtome.
(3) Place the section on a copper mesh, set it on a high-resolution electron microscope JEM-2010 (JEOL Ltd.), and photograph it at a magnification of 500,000 at an applied voltage of 200 kV.
(4) The negative is enlarged 3 to 10 times and printed.
(5) Observing the surface of the toner with a diameter of 80% or more and 120% or less of the volume average particle diameter of the toner in the printing by the procedure of (1) to (4), and the state of the surface coating of the external additive on the entire surface of the toner. Evaluate. The coverage is obtained from the following formula.
Formula: Coverage = (covering length/toner peripheral length) x 100 (%)
Here, the coating length refers to the length of the external additive layer that is in direct contact with the surface of the toner particles. In the present embodiment, the coverage is the average coverage of 10 toner particles.

- Toner Fluidity Index -
The fluidity index of the toner stored for 24 hours in an environment of 50° C. and 50% humidity is preferably 20 or less, more preferably 19 or less, and even more preferably 18 or less.
A toner having a fluidity index within the above range has good fluidity even under high temperature and high humidity conditions.

The liquidity index is calculated as follows.
Using a powder tester (manufactured by Hosokawa Micron Corporation), sieves with openings of 53 μm, 45 μm, and 38 μm are arranged in series from the top. Accurately weighed 2 g of toner is placed on a sieve with an opening of 53 μm, and vibrated with an amplitude of 1 mm for 90 seconds.
Formula: Fluidity index (%) = [(mass of toner on a sieve with an opening of 53 μm) x 0.5 + (mass of toner on a sieve with an opening of 45 µm) x 0.3 + (mass of toner on a sieve with an opening of 38 µm) )×0.1]×100/(mass of toner used for measurement)

<Electrostatic charge image developer>
The electrostatic charge image developer according to the exemplary embodiment contains at least the toner according to the exemplary embodiment.
The electrostatic charge image developer according to this embodiment may be a one-component developer containing only the toner according to this embodiment, or may be a two-component developer in which the toner and carrier are mixed.

The carrier is not particularly limited and includes known carriers. Examples of carriers include coated carriers in which the surface of a core material made of magnetic powder is coated with a coating resin; magnetic powder-dispersed carriers in which magnetic powder is dispersed and blended in a matrix resin; porous magnetic powder impregnated with resin. resin-impregnated carrier;
The magnetic powder-dispersed carrier and the resin-impregnated carrier may be a carrier in which constituent particles of the carrier are used as a core material and coated with a coating resin.

Magnetic powders include, for example, magnetic metals such as iron, nickel and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of coating resins and matrix resins include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid ester. Examples include copolymers, straight silicone resins containing organosiloxane bonds or modified products thereof, fluororesins, polyesters, polycarbonates, phenolic resins, epoxy resins, and the like.
The coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of conductive particles include particles of metals such as gold, silver, and copper, and particles of carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, potassium titanate, and the like.

Here, in order to coat the surface of the core material with the coating resin, there is a method of coating with a coating layer forming solution in which the coating resin and, if necessary, various additives are dissolved in an appropriate solvent. 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 an immersion method in which the core material is immersed in the solution for forming the coating layer, a spray method in which the solution for forming the coating layer is sprayed on the surface of the core material, and a state in which the core material is suspended by flowing air. Examples include a fluidized bed method in which a coating layer forming solution is sprayed, and a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater and the solvent is removed.

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

<Image forming apparatus/image forming method>
An image forming apparatus/image forming method according to the present embodiment will be described.
The image forming apparatus according to the present embodiment includes an image carrier, charging means for charging the surface of the image carrier, electrostatic image forming means for forming an electrostatic charge image on the surface of the charged image carrier, and electrostatic charging. developing means for storing an image developer and developing an electrostatic charge image formed on the surface of the image carrier with the electrostatic charge image developer as a toner image; and a recording medium for transferring the toner image formed on the surface of the image carrier. and a fixing means for fixing the toner image transferred to the surface of the recording medium. As the electrostatic charge image developer, the electrostatic charge image developer according to the exemplary embodiment is applied.

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

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

In addition, 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 detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge including developing means containing the electrostatic image developer according to the present embodiment is preferably used.

An example of the image forming apparatus according to the present embodiment will be shown below, but the present invention is not limited to this. Note that the main parts shown in the drawings will be explained, and the explanation of the others will be omitted.

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to this embodiment.
The image forming apparatus shown in FIG. 1 is a first to electrophotographic system for outputting yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as "units") 10Y, 10M, 10C, and 10K are arranged side by side with a predetermined distance from each other in the horizontal direction. These units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the image forming apparatus.

Above the units 10Y, 10M, 10C, and 10K in the drawing, an intermediate transfer belt 20 as an intermediate transfer member extends through each unit. The intermediate transfer belt 20 is wound around a drive roll 22 and a support roll 24 in contact with the inner surface of the intermediate transfer belt 20, which are spaced apart from each other from left to right in the drawing. It is designed to run in the direction toward the unit 10K. A force is applied to the support roll 24 in a direction away from the driving roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around both. An intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the drive roll 22 .
The developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K respectively store yellow, magenta, cyan, and black toner cartridges 8Y, 8M, 8C, and 8K. , a supply of toner containing four colors of toner is provided.

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here the first unit for forming a yellow image arranged on the upstream side in the running direction of the intermediate transfer belt is used. 10Y will be described as a representative. It should be noted that by attaching reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y) to portions equivalent to those of the first unit 10Y, the second to fourth The description of the units 10M, 10C, and 10K will be omitted.

The first unit 10Y has a photoreceptor 1Y acting as an image carrier. Around the photoreceptor 1Y, there is a charging roll (an example of charging means) 2Y that charges the surface of the photoreceptor 1Y to a predetermined potential, and the charged surface is exposed to a laser beam 3Y based on color-separated image signals. An exposure device (an example of an electrostatic charge image forming means) 3 for forming an electrostatic charge image by applying toner, a developing device (an example of a developing means) 4Y for supplying charged toner to the electrostatic charge image to develop the electrostatic charge image, and a developing device 4Y for developing the electrostatic charge image. A primary transfer roll 5Y (an example of primary transfer means) that transfers the toner image onto the intermediate transfer belt 20, and a photoreceptor cleaning device (an example of cleaning means) 6Y that removes toner remaining on the surface of the photoreceptor 1Y after the primary transfer. are arranged in order.
The primary transfer roll 5Y is arranged inside the intermediate transfer belt 20 and provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) that applies a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

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

An electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging. The laser beam 3Y lowers the resistivity of the irradiated portion of the photosensitive layer, causing the charged charges on the surface of the photoreceptor 1Y to flow. , on the other hand, a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoreceptor 1Y is rotated to a predetermined development position as the photoreceptor 1Y runs. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) as a toner image by the developing device 4Y.

The developing device 4Y contains, for example, an electrostatic charge image developer containing at least yellow toner and carrier. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has the same polarity (negative polarity) as the charged charge on the photoreceptor 1Y. One example) is held above. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically adhered to the static-eliminated latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to travel at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

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

Also, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is controlled according to the first unit.
In this way, the intermediate transfer belt 20 to which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in multiple layers. be.

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

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

Examples of the recording paper P onto which the toner image is transferred include plain paper used in electrophotographic copiers, printers, and the like. In addition to the recording paper P, the recording medium may be an OHP sheet or the like.
In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is also preferably smooth. be done.

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

<Process Cartridge/Toner Cartridge>
A process cartridge according to this embodiment will be described.
The process cartridge according to this embodiment is a developing means that stores the electrostatic charge image developer according to this embodiment, and develops the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer. and is detachable from the image forming apparatus.

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

An example of the process cartridge according to the present embodiment will be shown below, but the present invention is not limited to this. Note that the main parts shown in the drawings will be explained, and the explanation of the others will be omitted.

FIG. 2 is a schematic configuration diagram showing the process cartridge according to this embodiment.
The process cartridge 200 shown in FIG. 2 includes, for example, a photoreceptor 107 (an example of an image carrier) and a periphery of the photoreceptor 107 by means of a housing 117 having mounting rails 116 and an opening 118 for exposure. A charging roll 108 (an example of charging means), a developing device 111 (an example of developing means), and a photoreceptor cleaning device 113 (an example of cleaning means) are integrally combined and held, and formed into a cartridge. there is
In FIG. 2, 109 is an exposure device (an example of electrostatic charge image forming means), 112 is a transfer device (an example of transfer means), 115 is a fixing device (an example of fixing means), and 300 is recording paper (a recording medium). example) is shown.

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

The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8M, 8C, and 8K are detachable. ) is connected to a toner cartridge through a toner supply pipe (not shown). In addition, when the toner contained in the toner cartridge runs out, the toner cartridge is replaced.

The embodiments of the invention will be described in detail below with reference to examples, but the embodiments of the invention are not limited to these examples. In the following description, "parts" are based on mass unless otherwise specified.

[Example A]
<Example A1>
(Preparation of amorphous polyester resin dispersion (A1))
・Terephthalic acid: 70 parts ・Fumaric acid: 30 parts ・Ethylene glycol: 45 parts ・1,5-Pentanediol: 46 parts

A 5-liter flask equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a rectifying column was charged with the above materials, and the temperature was raised to 220°C over 1 hour under a nitrogen gas stream. 1 part of titanium tetraethoxide was added to a total of 100 parts of While distilling off the generated water, the temperature was raised to 240° C. over 0.5 hours, the dehydration condensation reaction was continued at this temperature for 1 hour, and then the reactants were cooled. Thus, a polyester resin having a weight average molecular weight of 9500, a glass transition temperature of 62° C. and an SP value of 10.2 was synthesized.

40 parts of ethyl acetate and 25 parts of 2-butanol were added to a container equipped with a temperature control means and a nitrogen substitution means to form a mixed solvent, and then 100 parts of a polyester resin was gradually added to dissolve the mixed solvent. % ammonia aqueous solution (equivalent to 3 times the molar acid value of the resin) was added and stirred for 30 minutes. Next, the inside of the container was replaced with dry nitrogen, the temperature was maintained at 40° C., and 400 parts of ion-exchanged water was added dropwise at a rate of 2 parts/minute while stirring the mixture to emulsify. After completion of dropping, the emulsion was returned to 25° C. to obtain a resin particle dispersion in which resin particles having a volume average particle diameter of 200 nm were dispersed. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 20% by mass to obtain an amorphous polyester resin dispersion (A1).

(Preparation of crystalline polyester resin dispersion (A1))
1,10-decanedicarboxylic acid: 98 parts Dimethyl isophthalate-sodium 5-sulfonate: 24 parts 1,9-nonanediol: 100 parts Dibutyl tin oxide (catalyst): 0.3 parts by mass

After the above components were placed in a heat-dried three-necked flask, the air in the container was made inert with nitrogen gas by depressurization, and the mixture was stirred and refluxed at 180° C. for 5 hours with mechanical stirring. After that, the temperature was gradually raised to 230°C under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was air-cooled to stop the reaction to obtain crystalline polyester resin A1 (specific crystalline polyester resin). rice field. According to molecular weight measurement (converted to polystyrene), the obtained "crystalline polyester resin A1" had a weight average molecular weight (Mw) of 9700, a melting temperature of 78°C, and an SP value of 9.3.

90 parts by mass of the obtained crystalline polyester resin A1, 1.8 parts by mass of the ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.), and 210 parts by mass of ion-exchanged water were heated to 100°C. , IKA Ultra Turrax T50 after dispersion, dispersion treatment was performed for 1 hour with a pressure discharge type Gaulin homogenizer, and a crystalline polyester resin dispersion having a volume average particle diameter of 200 nm and a solid content of 20 parts by mass (A1 ).

(Preparation of Release Agent Particle Dispersion A1)
・Paraffin wax (Nippon Seiro Co., Ltd. HNP-9): 100 parts ・Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part ・Ion-exchanged water: 350 parts After mixing and heating to 100° C., dispersing using a homogenizer (Ultra Turrax T50, manufactured by IKA), dispersion treatment is performed using a Manton-Gaulin high-pressure homogenizer (manufactured by Gorlin) to obtain release agent particles having a volume average particle diameter of 200 nm. A release agent particle dispersion A1 (solid content: 20% by mass) was obtained.

(Preparation of black colored particle dispersion liquid A1)
・Carbon black (Regal 330, manufactured by Cabot Corporation): 50 parts ・Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku): 5 parts ・Ion-exchanged water: 192.9 parts Co., Ltd.) at 240 MPa for 10 minutes to prepare black colored particle dispersion liquid A1 (solid concentration: 20% by mass).

(Preparation of toner particles (A1))
・Ion-exchanged water: 200 parts ・Amorphous polyester resin dispersion (A1): 150 parts ・Crystalline polyester resin dispersion (A1): 10 parts ・Black colored particle dispersion A1: 15 parts ・Release agent particle dispersion Liquid A1: 10 parts Anionic surfactant (TaycaPower): 2.8 parts

The above materials were placed in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and polyaluminum chloride (PAC, manufactured by Oji Paper Co., Ltd.: 30% powder)2. An aqueous PAC solution in which 0 part was dissolved in 30 parts of ion-exchanged water was added. After dispersing at 30° C. using a homogenizer (Ultra Turrax T50 manufactured by IKA), the mixture was heated to 45° C. in a heating oil bath and held until the volume average particle diameter reached 4.8 μm. After that, 60 parts of the amorphous polyester resin particle dispersion (A1) was added and the mixture was held for 30 minutes. After that, when the volume average particle diameter reached 5.2 μm, 60 parts of the amorphous polyester resin particle dispersion (A1) was further added and kept for 30 minutes. Subsequently, after adding 20 parts of a 10 mass % NTA (nitrilotriacetic acid) metal salt aqueous solution (Cherest 70: manufactured by Cherest Co., Ltd.), the pH was adjusted to 9.0 using a 1N sodium hydroxide aqueous solution. After that, an anion active agent (Tayca Power): 1.0 parts was added, and the mixture was heated to 85° C. while stirring was continued, and held for 5 hours. After cooling to 20° C. at a rate of 20° C./min, the mixture was filtered, thoroughly washed with deionized water, and dried to obtain toner particles (A1) having a volume average particle size of 6.0 μm.

(Preparation of specific silica particles (AA))
- Granulation process of silica particles -
420 parts of methanol and 74 parts of 10% by mass ammonia water were put into a glass reaction vessel equipped with a stirrer, a dropping nozzle, and a thermometer, and mixed to obtain an alkaline catalyst solution. After adjusting the alkali catalyst solution to 30° C., 180 parts of tetramethoxysilane (TMOS) and 52 parts of 8 mass % aqueous ammonia were added dropwise while stirring the alkali catalyst solution to obtain a silica particle dispersion. Dropping of TMOS and 8 mass % ammonia water was started simultaneously, and the entire amount of each was dropped over 10 minutes. Next, the silica particle dispersion was concentrated to a solid concentration of 40% by mass using a rotary filter (R-Fine manufactured by Kotobuki Kogyo Co., Ltd.). The concentrated silica particle dispersion was designated as silica particle dispersion (A1).

- Surface treatment process of silica particles -
To 250 parts of the silica particle dispersion (A1), 100 parts of hexamethyldisilazane (HMDS) was added as a hydrophobizing agent, heated to 160° C. and reacted for 2 hours. Next, after the silica particle dispersion after the reaction was dried by spray drying, specific silica particles (AA) were obtained.

(Preparation of Toner (A1))
To 100 parts by mass of the obtained toner particles (A1), 1.10 parts by mass of the obtained specific silica particles (AA) and hydrophobic silica (other silica particles, manufactured by Nippon Aerosil Co., Ltd., RY50, 2.8 parts by mass of BET specific surface area: 20 m ² /g) and 0.05 parts by mass of tetrakistrimethylsiloxysilane (low-molecular-weight siloxane, manufactured by Tokyo Chemical Industry Co., Ltd., T3494) were put into a sample mill and subjected to 10000 rpm for 30 seconds. Mixed. Thereafter, the toner (A1) was prepared by sieving with a vibrating sieve having an opening of 45 μm. The volume average particle size of the obtained toner (A1) was 6.0 μm.
The content of low-molecular-weight siloxane in toner (A1) was 3.8 ppm with respect to the total weight of the toner.
Table 1 shows the average primary particle size (“particle size” in Table 1) and BET specific surface area (“BET” in Table 1) of the specific silica particles (AA).
In addition, Table 1 shows the ΔH2/ΔH1 value, the coverage of the external additive (“coverage” in Table 1), and the fluidity index of the obtained toner (A1).

The average primary particle size of the specific silica particles was measured as follows.
Observation (50,000 times) with a scanning electron microscope (SEM: S-4700 type, manufactured by Hitachi, Ltd.) was performed for 100 fields, and each external additive (when a composite external additive was added, energy dispersion attached to an electron microscope S4100 Using an X-ray analyzer EMAX model 6923H (manufactured by Horiba, Ltd.), mapping was performed at an acceleration voltage of 20 kV, and the external additive type was determined. The average value of (obtained by approximating a circle) was measured at 1000 points, and the average value was taken as the "average primary particle size of the specific silica particles").

<Example A2>
In the preparation of the toner particles (A1), instead of cooling to 20°C at a rate of 20°C/min, cooling to 60°C at a rate of 20°C/min was maintained for 30 minutes, followed by cooling to 20°C at a rate of 10°C/min. Toner particles (A2) were obtained in the same manner as in Example A1, except that the mixture was cooled to °C.
Toner (A2) of Example A2 was obtained in the same manner as the toner (A1) of Example A1, except that the toner particles (A2) were used instead of the toner particles (A1).
Table 1 shows the ΔH2/ΔH1 value, external additive coverage (“coverage” in Table 1), and fluidity index for toner (A2).

<Example A3>
Toner particles (A3) were prepared in the same manner as in Example A1, except that the toner particles (A1) were cooled to 20°C at a rate of 30°C/min instead of cooling to 20°C at a rate of 20°C/min. ).
Toner (A3) of Example A3 was obtained in the same manner as Toner (A1) of Example A1, except that Toner Particles (A3) were used instead of Toner Particles (A1).
Table 1 shows the ΔH2/ΔH1 value, external additive coverage (“coverage” in Table 1), and fluidity index for toner (A3).

<Example A4 to Example A6>
Instead of using 1.10 parts by mass of the specific silica particles AA as the specific silica particles, the amount of the specific silica particles shown in Table 1 is added in the amount shown in Table 1 ("amount" in Table 1, unit is parts by mass ), Toner (A4) to Toner (A6) of Examples A4 to A6 were obtained in the same manner as Toner (A1) of Example A1, respectively, except that they were used in Example A1.
The content of low-molecular-weight siloxane in toner (A4) was 3.9 ppm based on the total weight of the toner.
The content of low-molecular-weight siloxane in toner (A5) was 4.0 ppm based on the total weight of the toner.
The content of low-molecular-weight siloxane in toner (A6) was 3.8 ppm based on the total weight of the toner.
Table 1 shows the ΔH2/ΔH1 values, external additive coverage (“coverage” in Table 1), and fluidity index for toners (A4) to (A6).
In Table 1, "AB" to "AD" in the types of silica particles indicate the following specific silica particles, respectively, specific silica particles (AB) to specific silica particles (AD) Table 1 shows the average primary particle size (“particle size” in Table 1) and BET specific surface area (“BET” in Table 1).

(Preparation of specific silica particles (AB))
In the preparation of the specific silica particles (AA), instead of adding 420 parts of methanol and 74 parts of 10% by mass ammonia water, 280 parts of methanol and 68 parts of 10% by mass ammonia water were added, and the temperature was 160 ° C. in the surface treatment step. Specific silica particles (AB) were obtained in the same manner as the specific silica particles (AA), except that instead of heating to 150 ° C. and reacting for 2 hours, the reaction was performed for 2.5 hours. .

(Preparation of specific silica particles (AC))
In the preparation of the specific silica particles (AA), instead of dropping 180 parts of tetramethoxysilane (TMOS) and 52 parts of 8% by mass ammonia water, 120 parts of tetramethoxysilane (TMOS) and 64 parts of 8% by mass ammonia water and changed the dropping time from 10 minutes to 12 minutes, and in the surface treatment step, instead of heating to 160 ° C. and reacting for 2 hours, heating to 150 ° C. and reacting for 1.5 hours. obtained the specific silica particles (AC) in the same manner as the specific silica particles (AA).

(Preparation of specific silica particles (AD))
In the preparation of the specific silica particles (AA), instead of dropping 180 parts of tetramethoxysilane (TMOS) and 52 parts of 8% by mass ammonia water, 200 parts of tetramethoxysilane (TMOS) and 48 parts of 8% by mass ammonia water and was added dropwise, and in the surface treatment step, instead of heating to 160 ° C. and reacting for 2 hours, it was heated to 150 ° C. and reacted for 2.5 hours. Same as the specific silica particles (AA). Then, specific silica particles (AD) were obtained.

<Example A7>
In the preparation of toner (A1), the amount of specific silica particles added ("amount" in Table 1, units are parts by mass) is as shown in Table 1, and the stirring speed of the sample mill among the blending conditions is from 10000 rpm. Toner (A7) of Example A7 was obtained in the same manner as toner (A1) of Example A1 except that the speed was changed to 8500 rpm and the stirring time was changed from 30 seconds to 25 seconds.
The content of low-molecular-weight siloxane in toner (A7) was 2.9 ppm based on the total weight of the toner.
Table 1 shows the ΔH2/ΔH1 value, external additive coverage (“coverage” in Table 1), and fluidity index for toner (A7).

<Example A8>
In the preparation of toner (A1), the amount of specific silica particles added ("amount" in Table 1, units are parts by mass) is as shown in Table 1, and the stirring speed of the sample mill among the blending conditions is from 10000 rpm. Toner (A8) of Example A8 was obtained in the same manner as toner (A1) of Example 1, except that the speed was changed to 12000 rpm and the stirring time was changed from 30 seconds to 45 seconds.
The content of low-molecular-weight siloxane in toner (A8) was 4.2 ppm with respect to the total weight of the toner.
Table 1 shows the ΔH2/ΔH1 value, external additive coverage (“coverage” in Table 1), and fluidity index for toner (A8).

<Comparative Example C1>
Toner particles (C1) were prepared in the same manner as in Example A1, except that the toner particles (A1) were cooled to 20°C at a rate of 35°C/min instead of cooling to 20°C at a rate of 20°C/min. got
Toner (C1) of Comparative Example C1 was obtained in the same manner as the toner (A1) of Example A1, except that the toner particles (C1) were used instead of the toner particles (A1).
Table 1 shows the ΔH2/ΔH1 value, the coverage of the external additive (“coverage” in Table 1), and the fluidity index for toner (C1).

<Comparative Example C2>
Instead of using 1.10 parts by mass of the specific silica particles (AA), silica particles of the types shown in Table 1 were added in the amount shown in Table 1 ("amount" in Table 1, unit: parts by mass). Toner (C2) of Comparative Example C2 was obtained in the same manner as the toner (A1) of Example A1 except for the above.
The content of low-molecular-weight siloxane in toner (C2) was 3.8 ppm with respect to the total weight of the toner.
Table 1 shows the ΔH2/ΔH1 value, the coverage of the external additive (“coverage” in Table 1), and the fluidity index of the toner (C2).
In Table 1, "AE" in the type of silica particles indicates the following silica particles, and the average primary particle size ("particle size" in Table 1) and BET ratio of silica particles (AE) The surface area (“BET” in Table 1) is shown in Table 1.

(Preparation of silica particles (AE))
In the preparation of the specific silica particles (AA), instead of adding 420 parts of methanol and 74 parts of 10% by mass ammonia water, 275 parts of methanol and 68 parts of 10% by mass ammonia water were added, and tetramethoxysilane (TMOS) was added. Instead of dropping 180 parts and 52 parts of 8% by mass aqueous ammonia, 195 parts of tetramethoxysilane (TMOS) and 50 parts of 8% by mass aqueous ammonia were dropped and heated to 160° C. in the surface treatment step. Silica particles (AE) were obtained in the same manner as the specific silica particles (AA), except that instead of reacting for 2 hours, the mixture was heated to 150° C. and reacted for 3.0 hours.

<Production of carrier>
・Ferrite particles (volume average particle diameter: 50 μm): 100 parts ・Toluene: 14 parts ・Styrene-methyl methacrylate copolymer: 2 parts (component ratio: 90/10, Mw = 80000)
Carbon black (R330: manufactured by Cabot Corporation): 0.2 parts First, the components except for the ferrite particles were stirred with a stirrer for 10 minutes to prepare a dispersed coating liquid. was placed in a vacuum degassing kneader and stirred at 60° C. for 30 minutes, degassed under reduced pressure while being heated, and dried to obtain a carrier.

<Production of developer>
Each toner and carrier thus obtained were placed in a V blender at a ratio of toner:carrier=5:95 (mass ratio) and stirred for 20 minutes to obtain each developer.

<Evaluation>
(Evaluation of residual toner and adhesion of external additives in cartridge)
Toner residue ("residue" in Table 1) and external additive adhesion ("adhesion" in Table 1) on the cartridge were evaluated by the following methods and criteria. Table 1 shows the results.
310 g of the toner to be evaluated was filled in a transparent toner cartridge made of PET (polyethylene terephthalate) and seasoned (left) for 17 hours in an environment of 28° C. and 85%.
After that, under an environment of 22° C. 15%, the toner cartridge was attached to a replenishing device (a replenishing device for replenishing toner from the toner cartridge to the toner storage container) having a conveying nozzle. The rotation of the toner container and the operation of the replenishing device were performed for 50 minutes, the toner in the toner cartridge was discharged from the toner cartridge, and the weight of the discharged toner was measured to confirm the remaining amount of toner in the cartridge ( remaining toner in cartridge).
After that, the toner cartridge was gently tilted to discharge the toner remaining at the bottom of the toner cartridge, and the adhesion of the external additive to the wall surface inside the toner cartridge was confirmed (external additive adhesion evaluation inside the cartridge).

The conditions for rotating the toner container and operating the replenishing device are as follows.
Toner container rotation speed: 30 rpm
Conveyor nozzle length of replenishment device: 70 mm
Screw pitch in conveying path: 12.5mm
Conveying screw outer diameter: 10mm
Conveying screw shaft diameter: 4mm
Conveying screw rotation speed: 62.4 rpm

Evaluation criteria for evaluation of remaining toner in the cartridge are as follows.
G1: Less than 25 g of toner remaining in the cartridge (no problem in actual use)
G2: The amount of toner remaining in the cartridge is 25 g or more and less than 50 g (no problem in actual use)
G3: Remaining amount of toner in cartridge is 50 g or more (problem in actual use)

The evaluation criteria for evaluating the adhesion of external and internal additives to the cartridge are as follows.
G1: No external additive adhering to the wall surface and no whitening G2: A slight amount of external additive adhering to the wall surface and whitening, but no problem in practical use G3: External additive adhering to the wall surface It turns white as a whole, and there is a problem in actual use.

(External Additive Removability Evaluation)
The ability to remove the external additive from the toner particles (“Release” in Table 1) was evaluated according to the following method and criteria. Table 1 shows the results.
First, 100 ml of ion-exchanged water and 5.5 ml of 10% by weight octylphenol ethoxylate (Triton X100 aqueous solution (manufactured by Acros Organics)) were added to a 200 ml glass bottle, and 5 g of the toner to be evaluated was added to the mixture. Stir twice and let stand for 1 hour or longer.

Then, after stirring the mixed solution 20 times, an ultrasonic homogenizer (manufactured by SONICS & MATERIALS Co., Ltd., product name homogenizer, model VCX750, CV33) was used to set the dial to output 30%, and ultrasonic energy was applied under the following conditions. Apply for 1 minute.
・Vibration time: 60 seconds continuously ・Amplitude: Set to 20W (30%) ・Vibration start temperature: 40±1.5℃
・Distance between the ultrasonic transducer and the bottom of the container: 10 mm

Next, the mixed solution to which ultrasonic energy has been applied is subjected to suction filtration using filter paper [trade name: qualitative filter paper (No. 2, 110 mm), manufactured by Advantec Toyo Co., Ltd.], and washed again with deionized water twice, After removing loose particles by filtration, the toner is dried.
The amount of particles remaining in the toner after the particles have been removed by the above treatment (hereinafter referred to as the amount of particles after dispersion) and the amount of particles in the toner that has not been subjected to the above treatment to remove the particles (hereinafter referred to as the amount of particles before dispersion). ) are quantified by the fluorescent X-ray method, and the values of the particle amount before dispersion and the particle amount after dispersion are substituted into the following formula.
The value calculated by the following formula is defined as the particle detachment rate.
Formula: Particle separation rate (% by mass) = [(particle amount before dispersion - particle amount after dispersion)/particle amount before dispersion] x 100

The evaluation criteria for the withdrawal evaluation are as follows.
G1: Withdrawal rate is less than 30% (no problem in actual use)
G2: Withdrawal rate of 30% or more and less than 50% (no problem in practical use)
G3: Withdrawal rate is 50% or more (problem in actual use)

From the results in Table 1, it can be seen that the detachment of the external additive is suppressed in this example as compared with the comparative example. In addition, it can be seen that in the present example, adhesion of the external additive to the wall surface inside the cartridge is suppressed as compared with the comparative example when the environment changes from high temperature and high humidity to low temperature and low humidity.

[Example D]
<Example D1>
(Preparation of amorphous polyester resin dispersion (D1))
・Terephthalic acid: 70 parts ・Fumaric acid: 30 parts ・Ethylene glycol: 45 parts ・1,5-Pentanediol: 46 parts

A 5-liter flask equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a rectifying column was charged with the above materials, and the temperature was raised to 220°C over 1 hour under a nitrogen gas stream. 1 part of titanium tetraethoxide was added to a total of 100 parts of While distilling off the generated water, the temperature was raised to 240° C. over 0.5 hours, the dehydration condensation reaction was continued at this temperature for 1 hour, and then the reactants were cooled. Thus, a polyester resin having a weight average molecular weight of 9500, a glass transition temperature of 62° C. and an SP value of 10.2 was synthesized.

40 parts of ethyl acetate and 25 parts of 2-butanol were added to a container equipped with a temperature control means and a nitrogen substitution means to form a mixed solvent, and then 100 parts of a polyester resin was gradually added to dissolve the mixed solvent. % ammonia aqueous solution (equivalent to 3 times the molar acid value of the resin) was added and stirred for 30 minutes. Next, the inside of the container was replaced with dry nitrogen, the temperature was maintained at 40° C., and 400 parts of ion-exchanged water was added dropwise at a rate of 2 parts/minute while stirring the mixture to emulsify. After completion of dropping, the emulsion was returned to 25° C. to obtain a resin particle dispersion in which resin particles having a volume average particle diameter of 200 nm were dispersed. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 20% by mass to obtain an amorphous polyester resin dispersion (D1).

(Preparation of crystalline polyester resin dispersion (D1))
Dimethyl sebacate: 98 parts Sodium dimethyl isophthalate-5-sulfonate: 20 parts 1,5-pentanediol: 100 parts Dibutyl tin oxide (catalyst): 0.3 parts by mass

After the above components were placed in a heat-dried three-necked flask, the air in the container was made inert with nitrogen gas by depressurization, and the mixture was stirred and refluxed at 180° C. for 5 hours with mechanical stirring. After that, the temperature was gradually raised to 230°C under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was air-cooled to stop the reaction, thereby obtaining a crystalline polyester resin D1 (specific crystalline polyester resin). rice field. According to molecular weight measurement (converted to polystyrene), the obtained "crystalline polyester resin D1" had a weight average molecular weight (Mw) of 9700, a melting temperature of 84°C, and an SP value of 9.3.

90 parts by mass of the obtained crystalline polyester resin D1, 1.8 parts by mass of the ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.), and 210 parts by mass of deionized water are heated to 100°C. , IKA Ultra Turrax T50 after dispersion, dispersion treatment with a pressure discharge Gaulin homogenizer for 1 hour, the volume average particle diameter is 200 nm, the solid content is 20 parts by weight crystalline polyester resin dispersion liquid (D1 ).

(Preparation of Release Agent Particle Dispersion D1)
・ Paraffin wax (Nippon Seiro Co., Ltd. HNP-9): 100 parts ・ Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK): 1 part ・ Ion-exchanged water: 350 parts After mixing and heating to 100° C., dispersing using a homogenizer (Ultra Turrax T50, manufactured by IKA), dispersion treatment is performed using a Manton-Gaulin high-pressure homogenizer (manufactured by Gorlin) to obtain release agent particles having a volume average particle diameter of 200 nm. was dispersed to obtain a releasing agent particle dispersion D1 (solid content: 20% by mass).

(Preparation of Black Colored Particle Dispersion D1)
・Carbon black (Regal 330, manufactured by Cabot Corporation): 50 parts ・Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku): 5 parts ・Ion-exchanged water: 192.9 parts (manufactured by Co., Ltd.) at 240 MPa for 10 minutes to prepare a black colored particle dispersion liquid D1 (solid concentration: 20% by mass).

(Preparation of toner particles (D1))
・Ion-exchanged water: 200 parts by mass ・Amorphous polyester resin dispersion (D1): 150 parts ・Crystalline polyester resin dispersion (D1): 10 parts ・Black colored particle dispersion D1: 15 parts ・Releasing agent particles Dispersion D1: 10 parts Anionic surfactant (TaycaPower): 2.8 parts Tetrakistrimethylsiloxysilane: 0.5 parts by mass (manufactured by Tokyo Kasei Co., Ltd., T3494)

The above materials were placed in a round stainless steel flask, 0.1N nitric acid was added to adjust the pH to 3.5, and polyaluminum chloride (PAC, manufactured by Oji Paper Co., Ltd.: 30% powder)2. An aqueous PAC solution in which 0 part was dissolved in 30 parts of ion-exchanged water was added. After dispersing at 30° C. using a homogenizer (Ultra Turrax T50 manufactured by IKA), the mixture was heated to 45° C. in a heating oil bath and held until the volume average particle diameter reached 4.8 μm. After that, 60 parts of the amorphous polyester resin particle dispersion (D1) was added and the mixture was held for 30 minutes. After that, when the volume average particle diameter reached 5.2 μm, 60 parts of the amorphous polyester resin particle dispersion (D1) was further added and kept for 30 minutes. Subsequently, after adding 20 parts of a 10 mass % NTA (nitrilotriacetic acid) metal salt aqueous solution (Cherest 70: manufactured by Cherest Co., Ltd.), the pH was adjusted to 9.0 using a 1N sodium hydroxide aqueous solution. After that, an anion active agent (Tayca Power): 1.0 parts was added, and the mixture was heated to 85° C. while stirring was continued, and held for 5 hours. After that, after cooling to 60 ° C. at a rate of 20 ° C./min and holding for 30 minutes, cooling to 20 ° C. at a rate of 10 ° C./min, filtering, washing thoroughly with ion-exchanged water, and drying, the volume average Toner particles (D1) having a particle size of 6.0 μm were obtained.

(Preparation of specific silica particles (DA))
- Granulation process of silica particles -
400 parts of methanol and 74 parts of 10% by mass ammonia water were put into a glass reactor equipped with a stirrer, a dropping nozzle, and a thermometer and mixed to obtain an alkaline catalyst solution. After adjusting the alkali catalyst solution to 30° C., 155 parts of tetramethoxysilane (TMOS) and 50 parts of 8 mass % aqueous ammonia were added dropwise while stirring the alkali catalyst solution to obtain a silica particle dispersion. Dropping of TMOS and 8 mass % ammonia water was started simultaneously, and the entire amount of each was dropped over 10 minutes. Next, the silica particle dispersion was concentrated to a solid content concentration of 40% by mass using a rotary filter (R-Fine manufactured by Kotobuki Kogyo Co., Ltd.). The concentrated silica particle dispersion was designated as silica particle dispersion (D1).

- Surface treatment process of silica particles -
To 250 parts of the silica particle dispersion (D1), 100 parts of hexamethyldisilazane (HMDS) was added as a hydrophobizing agent, heated to 155° C. and reacted for 2 hours. Next, after the silica particle dispersion after the reaction was dried by spray drying, specific silica particles (DA) were obtained.

(Preparation of Toner (D1))
Based on 100 parts by mass of the obtained toner particles (D1), 1.50 parts by mass of specific silica particles (DA) and hydrophobic silica (other silica particles, manufactured by Nippon Aerosil Co., Ltd., RY50, BET specific surface area : 20 m ² /g) was mixed with 1.50 parts by mass using a sample mill at 10000 rpm for 30 seconds. Thereafter, the toner (D1) was prepared by sieving with a vibrating sieve having an opening of 45 μm. The volume average particle diameter of the obtained toner (D1) was 6.0 μm.
The content of low-molecular-weight siloxane in toner (D1) was 0.5 ppm based on the total weight of the toner.
Table 2 shows the average primary particle size (“particle size” in Table 2) and BET specific surface area (“BET” in Table 2) of the specific silica particles (Silica DA).
Table 2 shows the ΔH2/ΔH1 value, the coverage of the external additive (“coverage” in Table 2), and the fluidity index of the obtained toner (D1).

The average primary particle size of the specific silica particles was measured as follows.
Observation (50,000 times) with a scanning electron microscope (SEM: S-4700 type, manufactured by Hitachi, Ltd.) was performed for 100 fields, and each external additive (when a composite external additive was added, energy dispersion attached to an electron microscope S4100 Using an X-ray analyzer EMAX model 6923H (manufactured by Horiba, Ltd.), mapping was performed at an acceleration voltage of 20 kV, and the external additive type was determined. The average value of (obtained by approximating a circle) was measured at 1000 points, and the average value was taken as the "average primary particle size of the specific silica particles").

<Example D2>
In the preparation of toner particles (D1), the amount of tetrakistrimethylsiloxysilane added was changed from 0.5 parts by mass to 1.3 parts by mass, and instead of cooling to 60°C at a rate of 20°C/min, Toner particles (D2) were obtained in the same manner as in Example D1, except that the mixture was cooled to 70° C. at a rate of .
A toner (D2) of Example D2 was obtained in the same manner as the toner (D1) of Example D1, except that the toner particles (D2) were used instead of the toner particles (D1).
The content of low-molecular-weight siloxane in toner (D2) was 1.3 ppm based on the total weight of the toner.
Table 2 shows the ΔH2/ΔH1 value, external additive coverage (“coverage” in Table 2), and fluidity index for toner (D2).

<Example D3>
In the preparation of toner particles (D1), the amount of tetrakistrimethylsiloxysilane added was changed from 0.5 parts by mass to 2.2 parts by mass, and instead of cooling to 60°C at a rate of 20°C/min, Toner particles (D3) were obtained in the same manner as in Example D1, except that the temperature was changed to 40°C.
Toner (D3) of Example D3 was obtained in the same manner as Toner (D1) of Example D1, except that Toner Particles (D3) were used instead of Toner Particles (D1).
The content of low-molecular-weight siloxane in toner (D3) was 2.2 ppm based on the total weight of the toner.
Table 2 shows the ΔH2/ΔH1 value, external additive coverage (“coverage” in Table 2), and fluidity index for toner (D3).

<Examples D4 to D5>
Instead of using 1.50 parts by mass of the specific silica particles (DA) as the specific silica particles, the toner of Example D1 ( Toner (D4) to Toner (D5) of Examples D4 to D5 were obtained in the same manner as in D1), respectively.
The content of low-molecular-weight siloxane in toner (D4) was 4.0 ppm based on the total weight of the toner.
The content of low-molecular-weight siloxane in toner (D5) was 2.0 ppm based on the total weight of the toner.
Table 2 shows the ΔH2/ΔH1 values, the coverage of the external additive (“coverage” in Table 2), and the fluidity index for the toners (D4) to (D5).
In Table 2, "D-B" to "D-C" in the types of silica particles indicate the following specific silica particles, respectively, specific silica particles (D-B) to specific silica particles (DC) Table 2 shows the average primary particle size (“particle size” in Table 2) and BET specific surface area (“BET” in Table 2).

Specific silica particles (D-B): specific silica particles, added amount 2.5 parts by mass (preparation of specific silica particles (D-B))
In the preparation of the specific silica particles (DA), instead of dropping 155 parts of tetramethoxysilane (TMOS) and 50 parts of 8% by mass ammonia water, 190 parts of tetramethoxysilane (TMOS) and 46 parts of 8% by mass ammonia water and was added dropwise, and in the surface treatment step, instead of heating to 155 ° C. and reacting for 2 hours, heating to 145 ° C. and reacting for 2.5 hours, in the same manner as the specific silica particles (DA), Specific silica particles (DB) were obtained.

Specific silica particles (D-C): Specific silica particles, addition amount 1.0 parts by mass [Preparation of hydrophobic silica particles (D-C)]
In the preparation of the specific silica particles (DA), instead of dropping 155 parts of tetramethoxysilane (TMOS) and 50 parts of 8% by mass ammonia water, 115 parts of tetramethoxysilane (TMOS) and 68 parts of 8% by mass ammonia water was dropped, and the dropping time was changed from 10 minutes to 14 minutes. Specific silica particles (DC) were obtained in the same manner as the specific silica particles (DA).

<Example D6>
In the preparation of toner particles (D1), the amount of tetrakistrimethylsiloxysilane added was changed from 0.5 parts by mass to 6.0 parts by mass. Same as Example D1, except that instead of cooling to 20°C at a rate of °C/min, it was cooled to 70°C at a rate of 15°C/min, held for 30 minutes, and then cooled to 20°C at a rate of 10°C/min. to obtain toner particles (D6).
Instead of using the toner particles (D6) instead of the toner particles (D1), and using 1.50 parts by mass of silica DA as the specific silica particles, the specific silica particles of the types shown in Table 2 are added in the following amounts. Toner (D6) of Example D6 was obtained in the same manner as the toner (D1) of Example D1 except that the toner (D6) was used.
The content of low-molecular-weight siloxane in toner (D6) was 6.0 ppm based on the total weight of the toner.
Table 2 shows the ΔH2/ΔH1 value, external additive coverage (“coverage” in Table 2), and fluidity index for toner (D6).
In Table 2, "DD" in the type of silica particles indicates the following specific silica particles, and the average primary particle size of the specific silica particles (DD) ("particle size" in Table 2) and Table 2 shows the BET specific surface area (“BET” in Table 2).

Specific silica particles (DD): Specific silica particles, added amount 2.5 parts by mass (preparation of silica particles (DD))
In the preparation of the specific silica particles (DA), instead of adding 400 parts of methanol and 74 parts of 10% by mass ammonia water, 320 parts of methanol and 68 parts of 10% by mass ammonia water were added, and tetramethoxysilane (TMOS) 155 190 parts of tetramethoxysilane (TMOS) and 46 parts of 8% by mass ammonia water are added dropwise instead of 190 parts of tetramethoxysilane (TMOS) and 50 parts of 8% by mass ammonia water, and heated to 155° C. to react for 2 hours in the surface treatment step. Specific silica particles (DD) were obtained in the same manner as the specific silica particles (DA), except that instead the mixture was heated to 150° C. and reacted for 2.5 hours.

<Example D7>
In the preparation of toner particles (D1), the amount of tetrakistrimethylsiloxysilane added was changed from 0.5 parts by mass to 4.0 parts by mass, cooled to 60° C. at a rate of 20° C./min, held for 30 minutes, and cooled to 60° C. Same as Example D1, except that instead of cooling to 20°C at a rate of °C/min, it was cooled to 65°C at a rate of 15°C/min, held for 30 minutes, and then cooled to 20°C at a rate of 10°C/min. to obtain toner particles (D7).
In the same manner as the toner (D1) of Example D1 except that the toner particles (D6) were used instead of the toner particles (D1) and the amount of the specific silica particles added was 2.2 parts by mass, A D7 toner (D7) was obtained.
The content of low-molecular-weight siloxane in toner (D7) was 4.0 ppm based on the total weight of the toner.
Table 2 shows the ΔH2/ΔH1 value, the coverage of the external additive (“coverage” in Table 2), and the fluidity index of the toner (D7).

<Comparative example F1>
In the preparation of toner particles (D1), the amount of tetrakistrimethylsiloxysilane added was changed from 0.5 parts by mass to 4.0 parts by mass, cooled to 60° C. at a rate of 20° C./min, held for 30 minutes, and cooled to 60° C. Same as Example D1, except that instead of cooling to 20°C at a rate of °C/min, it was cooled to 50°C at a rate of 30°C/min, held for 30 minutes, and then cooled to 20°C at a rate of 10°C/min. to obtain toner particles (F1).
Toner (F1) of Comparative Example F1 was obtained in the same manner as the toner (D1) of Example D1, except that the toner particles (F1) were used instead of the toner particles (D1).
The content of low-molecular-weight siloxane in toner (F1) was 4.0 ppm based on the total weight of the toner.
Table 2 shows the ΔH2/ΔH1 value, the coverage of the external additive (“coverage” in Table 2), and the fluidity index of the toner (F1).

<Comparative Example F2>
The toner (D1) of Example D1 was prepared in the same manner as the toner (D1) of Example D1, except that silica particles of the types shown in Table 2 were used in the following amounts instead of using 1.50 parts by mass of the specific silica particles (DA). , a toner (F2) of Comparative Example F2 was obtained.
The content of low-molecular-weight siloxane in toner (F2) was 4.0 ppm based on the total weight of the toner.
Table 2 shows the ΔH2/ΔH1 value, the coverage of the external additive (“coverage” in Table 2), and the fluidity index of the toner (F2).
In Table 2, "DH" in the type of silica particles indicates the following silica particles, the average primary particle size of silica particles (DH) ("particle size" in Table 2), BET ratio The surface area (“BET” in Table 2) is shown in Table 2.

Silica particles (DH): silica particles, added amount 2.0 parts by mass (preparation of silica particles (DH))
In the preparation of the specific silica particles (DA), instead of adding 400 parts of methanol and 74 parts of 10% by mass ammonia water, 295 parts of methanol and 72 parts of 10% by mass ammonia water were added, and tetramethoxysilane (TMOS) 155 195 parts of tetramethoxysilane (TMOS) and 50 parts of 8% by mass ammonia water are dropped instead of dropping parts and 50 parts of 8% by mass ammonia water, and in the surface treatment step, heating to 155 ° C. for 2 hours. Silica particles (DH) were obtained in the same manner as the specific silica particles (DA), except that instead of reacting, they were heated to 145° C. and reacted for 2.5 hours.

<Production of carrier>
・Ferrite particles (volume average particle diameter: 50 μm): 100 parts ・Toluene: 14 parts ・Styrene-methyl methacrylate copolymer: 2 parts (component ratio: 90/10, Mw = 80000)
Carbon black (R330: manufactured by Cabot Corporation): 0.2 parts First, the components except for the ferrite particles were stirred with a stirrer for 10 minutes to prepare a dispersed coating liquid. was placed in a vacuum degassing kneader and stirred at 60° C. for 30 minutes, degassed under reduced pressure while being heated, and dried to obtain a carrier.

<Production of developer>
Each toner and carrier thus obtained were placed in a V blender at a ratio of toner:carrier=5:95 (mass ratio) and stirred for 20 minutes to obtain each developer.

<Evaluation>
(Low temperature fixability evaluation)
Each of the obtained developers was filled into a developer of Fuji Xerox Co., Ltd.'s Apeoport 6-C7771 modified machine (fixer was modified so that the fixing temperature can be changed), and the surface temperature of the fixing roll of the fixing device was changed from 60°C to 10°C. C. to 200.degree. C., and images of the solid area (toner amount: 4.5 g/ ^m.sup.2 ) and fine line area were produced at each temperature. A crease was made on the inner side of the fixed image in the solid portion, and the destruction of the fixed image was visually evaluated. evaluated according to the standard. Table 2 shows the results.
-Evaluation Criteria for Low Temperature Fixability-
G1: MTF≦110° C. Excellent low temperature fixability G2: 110° C.<MTF≦120° C. No problem in practical use Fixability G3: 120° C.<MTF Problem occurs in practical use Fixability

(Transferability evaluation)
Using a modified DocuCentreColor 400 (manufactured by Fuji Xerox Co., Ltd.) in an environment with a temperature of 28 ° C. and a humidity of 85%, an image sample on which rectangular patches were written so that the image density was 1% was printed on embossed paper (Special Tokai Paper Co., Ltd.). After outputting the image to Lethac 66, 203 gsm manufactured by Epson Co., Ltd., the image quality was evaluated (confirmation of the presence or absence of color loss). When the obtained image was visually confirmed, the grade of transferability was determined according to the following criteria. Evaluation was made up to B in the allowable range. Table 2 shows the results.
-Transferability evaluation criteria-
G1: No color loss is present in the recesses of the embossed paper.
G2: In the depressions of the embossed paper, voids exist in the image area of 10% or less G3: In the depressions of the embossed paper, voids exist in the image area of less than 30% G4: In the depressions of the embossed paper Missing parts exist in the range where the image area is 30% or more

(External Additive Removability Evaluation)
The ability to remove the external additive from the toner particles (“Release” in Table 2) was evaluated according to the following method and criteria. Table 2 shows the results.
First, 100 ml of ion-exchanged water and 5.5 ml of 10% by weight octylphenol ethoxylate (Triton X100 aqueous solution (manufactured by Acros Organics)) were added to a 200 ml glass bottle, and 5 g of the toner to be evaluated was added to the mixture. Stir twice and let stand for 1 hour or longer.

Then, after stirring the mixed solution 20 times, an ultrasonic homogenizer (manufactured by SONICS & MATERIALS Co., Ltd., product name homogenizer, model VCX750, CV33) was used to set the dial to output 30%, and ultrasonic energy was applied under the following conditions. Apply for 1 minute.
・Vibration time: 60 seconds continuously ・Amplitude: Set to 20W (30%) ・Vibration start temperature: 40±1.5℃
・Distance between the ultrasonic transducer and the bottom of the container: 10 mm

Next, the mixed solution to which ultrasonic energy has been applied is subjected to suction filtration using filter paper [trade name: qualitative filter paper (No. 2, 110 mm), manufactured by Advantec Toyo Co., Ltd.], and washed again with deionized water twice, After removing loose particles by filtration, the toner is dried.
The amount of particles remaining in the toner after the particles have been removed by the above treatment (hereinafter referred to as the amount of particles after dispersion) and the amount of particles in the toner that has not been subjected to the above treatment to remove the particles (hereinafter referred to as the amount of particles before dispersion). ) are quantified by the fluorescent X-ray method, and the values of the particle amount before dispersion and the particle amount after dispersion are substituted into the following formula.
The value calculated by the following formula is defined as the particle detachment rate.
Formula: Particle separation rate (% by mass) = [(particle amount before dispersion - particle amount after dispersion)/particle amount before dispersion] x 100

The evaluation criteria for the withdrawal evaluation are as follows.
G1: Withdrawal rate is less than 30% (no problem in actual use)
G2: Withdrawal rate of 30% or more and less than 50% (no problem in practical use)
G3: Withdrawal rate is 50% or more (problem in actual use)

From the results in Table 2, it can be seen that the detachment of the external additive is suppressed in this example as compared with the comparative example. In addition, it can be seen that deterioration in transferability in a high-temperature and high-humidity environment is suppressed in the present example as compared with the comparative example.

1Y, 1M, 1C, 1K photoreceptors (examples of image carriers)
2Y, 2M, 2C, 2K charging roll (an example of charging means)
3 Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K laser beams 4Y, 4M, 4C, 4K developing device (an example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (an example of primary transfer means)
6Y, 6M, 6C, 6K photoreceptor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K toner cartridges 10Y, 10M, 10C, 10K image forming unit 20 intermediate transfer belt (an example of an intermediate transfer member)
22 drive roll 24 support roll 26 secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer body cleaning device 107 Photoreceptor (an example of an image carrier)
108 charging roll (an example of charging means)
109 exposure device (an example of electrostatic charge image forming means)
111 developing device (an example of developing means)
112 transfer device (an example of transfer means)
113 photoreceptor cleaning device (an example of cleaning means)
115 fixing device (an example of fixing means)
116 mounting rail 117 housing 118 opening 200 for exposure process cartridge 300 recording paper (an example of a recording medium)
P recording paper (an example of a recording medium)

Claims (17)

toner particles containing an amorphous resin and a crystalline polyester resin composed of a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms;
an external additive containing silica particles having a BET specific surface area of 100 m ² /g or more;
a low-molecular-weight siloxane composed only of siloxane bonds and alkyl groups and having a molecular weight of 200 or more and 600 or less;
has
In differential scanning calorimetry in accordance with ASTM D3418-8 (2008), the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the first heating process is ΔH1 (mW / g), and the second heating process. where ΔH2 (mW/g) is the endothermic amount based on the endothermic peak derived from the crystalline polyester resin in the electrostatic charge image developing toner satisfying the formula: 0.05≦ΔH2/ΔH1≦0.95. 2. The toner for electrostatic charge image development according to claim 1, which satisfies the formula: 0.35<[Delta]H2/[Delta]H1≤0.95. 3. The toner for electrostatic charge image development according to claim 2, which satisfies the formula: 0.45<ΔH2/ΔH1≦0.80. 2. The toner for electrostatic charge image development according to claim 1, which satisfies the formula: 0.05≤[Delta]H2/[Delta]H1≤0.35. 5. The toner for electrostatic charge image development according to claim 4, which satisfies the formula: 0.15≤[Delta]H2/[Delta]H1<0.25. The toner for electrostatic image development according to any one of claims 1 to 5, wherein the silica particles have an average primary particle size of 20 nm or more and 90 nm or less. The toner for electrostatic image development according to any one of claims 1 to 6, wherein the silica particles are sol-gel silica particles. 8. The toner for electrostatic charge image development according to any one of claims 1 to 7, wherein the coverage of the external additive is 80% or more. 9. The electrostatic charge image development according to any one of claims 1 to 8, wherein the toner for electrostatic charge image development stored for 24 hours in an environment of a temperature of 50°C and a humidity of 50% has a fluidity index of 20 or less. toner for. The toner for electrostatic charge image development according to any one of claims 1 to 9, wherein the low-molecular-weight siloxane is a low-molecular-weight siloxane having a tetrakis structure. 11. The toner for electrostatic charge image development according to claim 10, wherein the total content of the low-molecular-weight siloxane is 0.01 ppm or more and 10 ppm or less based on the mass of the toner for electrostatic charge image development. The difference (ΔSP value) between the solubility parameter (SP value) of the crystalline polyester resin and the solubility parameter (SP value) of the amorphous resin satisfies the range of 0.1 to 1.2. The toner for electrostatic charge image development according to claim 11 . An electrostatic charge image developer containing the electrostatic charge image developing toner according to any one of claims 1 to 12 . containing the electrostatic charge image developing toner according to any one of claims 1 to 12 ,
A toner cartridge that is attached to and detached from an image forming apparatus. 14. A developing means for storing the electrostatic charge image developer according to claim 13 and developing the electrostatic charge image formed on the surface of the image carrier by the electrostatic charge image developer as a toner image,
A process cartridge that is attached to and detached from an image forming apparatus. an image carrier;
charging means for charging the surface of the image carrier;
electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Developing means for accommodating the electrostatic charge image developer according to claim 13 and developing the electrostatic charge image formed on the surface of the image carrier by the electrostatic charge image developer as a toner image;
a transfer means for transferring the toner image formed on the surface of the image carrier onto the surface of a recording medium;
fixing means for fixing the toner image transferred onto the surface of the recording medium;
An image forming apparatus comprising: a charging step of charging the surface of the image carrier;
an electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
a developing step of developing the electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 13 ;
a transfer step of transferring the toner image formed on the surface of the image carrier onto the surface of a recording medium;
a fixing step of fixing the toner image transferred onto the surface of the recording medium;
An image forming method comprising:

Images