JP2012145649A - Production method of toner for electrostatic charge image development, toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of toner for electrostatic charge image development, for suppressing peeling of a coating layer coating a core of a toner particle.SOLUTION: The production method of toner for electrostatic charge image development includes: a first aggregated particle forming step of preparing at least a first resin particle dispersion liquid having first resin particles dispersed therein, and aggregating at least the first resin particles to form first aggregated particles; a second aggregated particle forming step of mixing the first aggregated particle dispersion liquid having the first aggregated particles dispersed therein with a second resin particle dispersion liquid having second resin particles dispersed therein, the second resin particles having a Vicat softening temperature different from that of the first resin particles, and aggregating the second resin particles as adhering to the surfaces of the first aggregated particles to form second aggregated particles; and a fusing and unifying step of heating the second aggregated particle dispersion liquid having the second aggregated particles dispersed therein to a temperature equal to or higher than the highest Vicat softening temperature between the Vicat softening temperatures of the first resin particles and of the second resin particles, at a temperature elevation rate of 0.5°C/sec or more, to fuse and unify the second aggregated particles.

Description

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

  A method of visualizing image information through an electrostatic latent image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic latent image formed on a photoreceptor by a charging process and an exposure process is developed with a developer containing toner, and visualized through a transfer process and a fixing process.

  For example, regarding a toner, Patent Document 1 proposes to prepare a toner by an emulsion aggregation polymerization method (EA method).

  Patent Document 2 discloses that “an aqueous dispersion (I) of resin fine particles (P1) containing a polyester resin (p1) having a softening point of 70 to 130 ° C., and an acrylic resin having a softening point of 120 to 190 ° C. ( p2) and an aqueous dispersion (II) of resin fine particles (P2) having an average particle size smaller than the average particle size of the resin fine particles (P1), and mixing the resin fine particles (P1) and the resin fine particles (P2). An electrophotographic toner manufacturing method in which resin fine particles (P1) are used as core particles to form a shell layer formed by associating resin fine particles (P2) on the surface of the core particles. Acrylic resin (p2) For producing an electrophotographic toner in which the softening point of the resin is higher than the softening point of the polyester (p1) and part or all of the resin fine particles (P1) and / or resin fine particles (P2) are colored. "But It is draft.

  Patent Document 3 states that “a core-shell toner having a core and a shell having a thickness of 0.01 μm to 2 μm on the surface of the core, and the toner contains at least a binder resin and a colorant. A toner in which the softening temperature ST of the shell and the softening temperature CT of the core measured by an SPM probe with a built-in heater satisfy the relationship of 1.1 ≦ ST / CT ≦ 2.0 ”: Proposed.

  Patent Document 4 states that “a toner in which core particles containing a binder resin and a colorant are coated with shell particles, and has a volume average particle diameter of 4.0 μm or more and 8.0 μm or less, and a number average The toner having a particle size of 3.0 μm or less is contained in a ratio of 8% or more and less than 25% by number of the whole toner, and a part of the shell particles is fused with at least one of the core particles and the shell particles. Thus, a “toner characterized by forming protrusions” has been proposed.

Japanese Patent No. 2537503 JP 2004-354706 A JP 2010-44354 A JP 2009-15175 A

  An object of the present invention is a method for producing an electrostatic charge image developing toner comprising a core and a coating layer covering the core, wherein the toner for developing an electrostatic charge image is prevented from being peeled off. It is to provide a manufacturing method.

The above problems have been solved by the present invention described below.
That is, the invention according to claim 1
A first aggregated particle forming step of preparing at least a first resin particle dispersion in which the first resin particles are dispersed, aggregating at least the first resin particles to form first aggregated particles;
Mixing the first aggregated particle dispersion in which the first aggregated particles are dispersed and the second resin particle dispersion in which the second resin particles having a higher Vicat softening temperature than the first resin particles are dispersed, A second aggregated particle forming step of aggregating the second resin particles so as to adhere to the surface of the first aggregated particles to form second aggregated particles;
The second aggregated particle dispersion in which the second aggregated particles are dispersed is heated at a temperature rising rate of 0.5 ° C./sec or more and above the Vicat softening temperature of the second resin particles, A fusion and coalescence process for fusing and coalescing the agglomerated particles;
A method for producing a toner for developing an electrostatic charge image.

The invention according to claim 2
In the fusion and coalescence step, the heating rate from the start of heating until reaching the Vicat softening temperature of the first resin particles, and the heating rate after reaching the Vicat softening temperature of the second resin particles, 2. The electrostatic charge image developing toner according to claim 1, wherein the heating is performed by increasing a temperature rising rate from reaching the Vicat softening temperature of the second resin particles after reaching the Vicat softening temperature of the first resin particles. Production method.

The invention according to claim 3
A core composed of a first resin;
A coating layer covering the surface of the core body, the coating layer including a second resin having a Vicat softening temperature higher by 10 ° C. or more than the first resin;
A toner for developing an electrostatic charge image.

The invention according to claim 4
The electrostatic charge image development according to claim 3, wherein the first resin constituting the core is a biomass resin, and the second resin constituting the coating layer is at least one selected from a polyester resin and a styrene acrylic resin. Toner.

The invention according to claim 5
An electrostatic charge image developer comprising at least the electrostatic charge image developing toner according to claim 3.

The invention according to claim 6
Containing the toner for developing an electrostatic image according to claim 3 or 4;
A toner cartridge to be attached to and detached from the image forming apparatus.

The invention according to claim 7 provides:
A developing means for accommodating the electrostatic charge image developer according to claim 5 and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus.

The invention according to claim 8 provides:
An image carrier,
Charging means for charging the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Developing means for containing the electrostatic charge image developer according to claim 5 and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the image carrier onto a transfer target;
Fixing means for fixing the toner image transferred onto the transfer medium;
Image forming apparatus comprising

The invention according to claim 9 is:
A charging step for charging 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 containing the electrostatic charge image developer according to claim 5 and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer;
A transfer step of transferring a toner image formed on the image carrier onto a transfer target;
A fixing step of fixing the toner image transferred onto the transfer medium;
An image forming method comprising:

According to the first aspect of the present invention, compared to the case where the fusion and coalescence process is not performed at a temperature rising rate of 0.5 ° C./sec or more, the electrostatic charge composed of the core body and the coating layer covering the core body A method for producing an image developing toner, wherein the peeling of the coating layer is suppressed without depending on the material of the core and the material of the coating layer covering the core. Can be provided.
According to the invention according to claim 2, in the fusion / unification step, the rate of temperature increase from the start of heating until reaching the Vicat softening temperature of the first resin particles and the Vicat softening temperature of the second resin particles are reached. Compared to the case where the heating is performed by slowing the heating rate from reaching the Vicat softening temperature of the second resin particles after reaching the Vicat softening temperature of the first resin particles, compared to the heating rate from It is possible to provide a method for producing an electrostatic image developing toner in which peeling of the coating layer is suppressed.

According to the invention which concerns on Claim 3, when not applying the coating layer comprised including 2nd resin whose Vicat softening temperature is 10 degreeC or more higher than 1st resin as a coating layer which coat | covers the surface of a core body In comparison, it is possible to provide a toner for developing an electrostatic charge image having better storage stability.
According to the fourth aspect of the invention, it is possible to provide a toner for developing an electrostatic charge image that maintains the basic characteristics of the toner and suppresses the environmental load.
According to the inventions according to claims 5, 6, 7, 8, and 9, the coating layer that covers the surface of the core body includes the second resin that differs from the first resin by a Vicat softening temperature of 10 ° C. or more. Compared to the case where the toner for developing an electrostatic charge image having a coating layer is not applied, the toner has a long storage period, excellent surface properties and charge controllability, and an electrostatic charge image developer and toner capable of obtaining a high-quality image A cartridge, a process cartridge, an image forming apparatus, and an image forming method can be provided.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment. 5 is a graph for explaining a temperature increase rate in a fusion / unification process in the method for producing an electrostatic charge image developing toner according to the exemplary embodiment. It is a schematic diagram for demonstrating the method of heating with a microwave. It is a schematic diagram for demonstrating the method of heating with a micro heat exchanger. 6 is a schematic diagram for explaining a method of heating with a micro heat exchanger in Embodiment 2. FIG.

  Embodiments that are examples of the present invention will be described below.

(Method for producing toner for developing electrostatic image)
The method for producing an electrostatic charge image developing toner according to the present embodiment (hereinafter simply referred to as “toner”) includes a first resin composed of first resin particles (first resin particles fused and combined). 1 resin) and a coating layer containing a second resin composed of second resin particles covering the core (second resin in which the second resin particles are fused and united) (hereinafter referred to as a toner) This is sometimes referred to as “core / shell toner”.
Specifically, a first aggregated particle forming step of preparing at least a first resin particle dispersion in which the first resin particles are dispersed, aggregating at least the first resin particles to form first aggregated particles,
The first aggregated particle dispersion in which the first aggregated particles are dispersed and the second resin particle dispersion in which the second resin particles having a higher Vicat softening temperature than the first resin particles are mixed, and the first aggregated A second aggregated particle forming step of aggregating the second resin particles so as to adhere to the surface of the particles to form second aggregated particles;
The second agglomerated particle dispersion in which the second agglomerated particles are dispersed is heated to a temperature rising rate of 0.5 ° C./sec or more and to a Vicat softening temperature or more of the second resin particles to obtain second agglomerated particles. Fusion / unification process to merge / unify,
A method for producing a toner for developing an electrostatic image having

Here, conventionally, an emulsion aggregation polymerization method (EA method) is known as a method for producing a core / shell structure toner.
In order to produce a core / shell structure toner by this emulsion aggregation polymerization method (EA method), as described above, it is performed through the first aggregated particle forming step, the second aggregated particle forming step, and the fusing / merging step.
However, when the second resin particles (second resin) constituting the coating layer having a higher Vicat softening temperature than the first resin particles (first resin) constituting the core are applied, the second resin particles comprising the second resin particles are used. It has been found that a toner in which a coating layer containing two resins is peeled off can be obtained.
This is because in the fusion / union process, the temperature at which the core part begins to fuse and coalesce is different from the temperature at which the coating layer part begins to fuse and coalesce. This is considered to be because the clothing layer part that started fusion / unification later cannot follow the shrinkage of the core part that has started, and the core and the coating layer cannot be welded.
Specifically, when fusion / union of the core part starts first, spheroidization occurs due to surface tension along with shrinkage, and then the coating layer part where fusion / union starts follows the shrinkage of the core part. It is considered that the second resin particles (second resin) constituting the coating layer may be detached.

The phenomenon in which the covering layer containing the second resin composed of the second resin particles peels off is caused by the first resin particles (first resin) constituting the core and the second resin particles (second resin) constituting the covering layer. ) And a Vicat softening temperature significantly different from each other (for example, a Vicat softening temperature difference of 10 ° C. or more) is considered to be easily generated.
With the recent increase in value and functionality of toner, for example, a functional resin (for example, a biomass resin) is applied as the first resin particles (first resin) constituting the core, and the basic characteristics of the toner ( For example, in order to maintain the charging property in particular, a core body such as a conventional binder resin (for example, polyester resin or styrene acrylic resin) is applied as the second resin particles (second resin) constituting the coating layer. It is expected that there will be more cases where the first resin particles (first resin) constituting the material and the second resin particles (second resin) constituting the coating layer are greatly different in Vicat softening temperature.

Therefore, in the toner manufacturing method according to the present embodiment, in the coalescing / merging process, heating is performed at a temperature increase rate of 0.5 ° C./sec or more and higher than the Vicat softening temperature of the second resin particles. Perform one step.
Thereby, peeling of the coating layer containing the second resin made of the second resin particles is suppressed without depending on the material of the core body and the material of the coating layer covering the core body.
The reason for this is not clear, but by performing rapid heating at a rate of temperature rise of 0.5 ° C./sec or more, there is a time difference between the start of the fusion / unification of the core part and the fusion / union of the coating layer part. This is presumably because the core layer and the coating layer can be welded by following the shrinkage of the core body portion that has started to be fused and coalesced, followed by the coating layer portion that has been later fused and coalesced.

  In particular, in the toner manufacturing method according to the present embodiment, the Vicat softening temperatures of the first resin particles (first resin) constituting the core and the second resin particles (second resin) constituting the coating layer are greatly different. Even if a thing (for example, Vicat softening temperature difference is 10 degreeC or more) is applied, peeling of the coating layer containing the second resin composed of the second resin particles is suppressed.

Here, in the toner manufacturing method according to the present embodiment, the first resin particles are converted into the first resin constituting the core body, that is, the binder resin constituting the core body, through the fusion and coalescence process. Thus, the second resin particles become the second resin constituting the coating layer covering the core, that is, the coating resin constituting the coating layer, through the fusion / unification process.
If the Vicat softening temperature of the second resin particles is higher than that of the first resin particles, the resins described in the toner according to this embodiment to be described later are applied to the first resin particles and the second resin particles. In addition, other constituent materials (for example, a colorant, a release agent, an external additive, and the like) are also applied to each material described in the toner according to the exemplary embodiment described later.

Details of each step of the toner manufacturing method according to the present embodiment will be described below.
In the toner manufacturing method according to this embodiment, a method for obtaining a toner containing a colorant and a release agent will be described. However, the colorant and the release agent are used as necessary. Of course, you may use other additives other than a coloring agent and a mold release agent.

-First aggregated particle forming step-
First, together with the first resin particle dispersion in which the first resin particles are dispersed, for example, a colorant particle dispersion in which the colorant particles are dispersed and a release agent dispersion in which the release agent particles are dispersed are prepared.

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

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

The surfactant is not particularly limited. For example, anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; amine salt type, quaternary ammonium salt type Nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based, and the like. Among these, an anionic surfactant and a cationic surfactant are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
Surfactant may be used individually by 1 type and may use 2 or more types together.

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

Examples of the volume average particle diameter of the first resin particles dispersed in the first resin particle dispersion include a range of 0.01 μm to 1 μm, and may be 0.08 μm to 0.8 μm. It may be 1 μm or more and 0.6 μm.
The volume average particle diameter of the first resin particles is measured with a laser diffraction particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.). Hereinafter, unless otherwise specified, the volume average particle diameter of the particles is measured in the same manner.

  As content of the resin particle contained in a 1st resin particle dispersion liquid, 5 mass% or more and 50 mass% or less are mentioned, for example, and 10 mass% or more and 40 mass% or less may be sufficient.

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

Next, the colorant particle dispersion and the release agent dispersion are mixed together with the first resin particle dispersion.
Then, in the mixed dispersion, the first resin particles, the colorant particles, and the release agent particles are hetero-aggregated to have a diameter close to a desired toner diameter, the first resin particles, the colorant particles, and the release agent particles. First agglomerated particles (core agglomerated particles) are formed.

Specifically, for example, a flocculant is added to the mixed dispersion, and the pH of the mixed dispersion is adjusted to acidic (for example, pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. Thereafter, the mixture is heated to a temperature equal to or lower than the Vicat softening temperature of the first resin particles (specifically, for example, the Vicat softening temperature of the first resin particles is −30 ° C. or higher and the Vicat softening temperature −10 ° C. or lower) and dispersed in the mixed dispersion. The formed particles are aggregated to form first aggregated particles.
In the first agglomerated particle forming step, for example, the flocculant is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is acidic (for example, pH is 2 or more). 5 or less) and, if necessary, after adding a dispersion stabilizer, the heating may be performed.

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

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include metal salt polymers.
A water-soluble chelating agent may be used as the chelating agent. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid, iminodiacid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), and the like.
As addition amount of a chelating agent, the inside of the range of 0.01 mass part or more and 5.0 mass parts or less is mentioned with respect to 100 mass parts of 1st resin particles (1st resin), for example, 0.1 mass part or more It may be less than 3.0 parts by mass.

-Second aggregated particle forming step-
Next, the obtained first aggregated particle dispersion in which the first aggregated particles are dispersed, and the second resin particle dispersion in which the second resin particles having a Vicat softening temperature higher than that of the first resin particles are dispersed. Mix.
Then, in this mixed dispersion, the second resin particles are aggregated so as to adhere to the surface of the first aggregated particles, thereby forming the second aggregated particles having the second resin particles adhered to the surface of the first aggregated particles. .

Specifically, for example, in the first aggregated particle forming step, the first aggregated particles reach the target particle size (for example, the volume average particle size is 1.5 μm or more, desirably 2.5 μm or more and 6.5 μm or less). Then, the second resin particle dispersion is mixed with the first aggregated particle dispersion, and heating is performed below the lower Vicat softening temperature of the first aggregated particles and the second resin particles.
Then, the progress of aggregation is stopped by setting the pH of the second aggregated particle dispersion to a range of, for example, about 6.5 or more and 8.5 or less.

  Here, examples of the volume average particle size of the second resin particles dispersed in the second resin particle dispersion include a range of 0.01 μm to 1 μm, and may be 0.05 μm to 0.8 μm. 0.1 μm or more and 0.6 μm may be used, but particularly preferably less than 0.3 μm (300 nm).

  Thereby, the second aggregated particles aggregated so that the second resin particles adhere to the surface of the first aggregated particles are obtained.

-Fusion / unification process-
Next, the second aggregated particle dispersion in which the second aggregated particles are dispersed is heated to a temperature increase rate of 0.5 ° C./sec or more and to a Vicat softening temperature or more of the second resin particles, and the second Fusing and coalescing aggregated particles.

The heating rate of heating for fusing and uniting is 0.5 ° C./sec or more, and desirably 0.5 ° C./sec or more and 10 ° C./sec or less.
By setting the heating rate within the above range, peeling of the resulting toner coating layer is suppressed.

Here, the heating for fusion and coalescence may be performed at a constant heating rate from the start of heating to a temperature reaching the Vicat softening temperature or higher of the second resin particles (see line A in FIG. 3). After reaching the Vicat softening temperature of the first resin particles, compared to the rate of temperature increase from the start until reaching the Vicat softening temperature of the first resin particles, and the rate of temperature increase after reaching the Vicat softening temperature of the second resin particles. It is preferable to increase the temperature rise rate until the Vicat softening temperature of the second resin particles is reached (see line B in FIG. 3).
The circularity of the toner is controlled without changing the surface property of the toner by the rate of temperature rise from the time when the Vicat softening temperature of the second resin particles is reached until the Vicat softening temperature of the first resin particles is reached. Excellent toner can be obtained.

In other words, fusing and uniting heating
The heating rate between the heating start Ts and the first resin particle less than the Vicat softening temperature Tl is “STs”,
The rate of temperature rise after the Vicat softening temperature Th of the second resin particles exceeds “STe”,
When the rate of temperature increase between the Vicat softening temperature Tl of the first resin particles and the Vicat softening temperature Th of the second resin particles is “STc”,
It is good to carry out so that the relationship of a following formula (A) and a formula (B) may be satisfy | filled.
Formula (A) STs <STc
Formula (B) STe <STc
However, the rate of temperature increase between each is 0.5 ° C./sec or more.

By performing heating that fuses and coalesces under the above conditions, peeling of the resulting toner coating layer is easily suppressed.
In addition, the temperature increase rate difference between STc and STs and the temperature increase rate difference between STc and STe are preferably 0.1 ° C./sec or more and 5 ° C./sec or less, for example.

  Here, the rate of temperature increase (° C./sec) between each is expressed by the equation (temperature difference between two target temperatures: ° C./time to reach one temperature from the two target temperatures: sec).

Examples of the heating method for fusing and coalescing under the above conditions include a method of heating with a microwave and a method of heating with a micro heat exchanger.
These heating methods are desirable because heating at the above temperature rising rate can be easily realized.
In particular, the method of heating by microwaves is advantageous in that the heating conditions can be easily selected because the microwave output and the like can be easily changed.
On the other hand, the method of heating by the micro heat exchanger is advantageous in that the heating and the like are simple and low-cost because the equipment has a simple configuration.

Specifically, as a method of heating by microwave, for example, as shown in FIG. 4, a microwave generator is disposed on the side surface of the tank in which the second aggregated particle dispersion is accommodated, and stirred with a stirrer. However, the second aggregated particle dispersion is heated by irradiating the second aggregated particle dispersion with the microwave generated from the microwave generator from the side surface side of the tank.
Here, although the microwave irradiation may be continuous, it is preferably performed intermittently from the viewpoint of adjusting the heating rate.

On the other hand, as a method of heating by the micro heat exchanger, for example, as shown in FIG. 5, a circulation pipe is arranged in a tank in which the second aggregated particle dispersion is accommodated, and the circulation pipe path is arranged. In addition, a micro heat exchanger, a circulation disperser (for example, a homogenizer for circulation) and a pump are connected, and the second aggregated particle dispersion is dispersed by the micro heat exchanger while circulating the second aggregated particle dispersion in the circulation pipe by the pump. Heat the solution. In addition, the 2nd aggregate particle dispersion liquid accommodated in the tank is stirred with a stirrer.
The micro heat exchanger may be composed of, for example, a fine pipe and a heating source, and a microwave generator may be adopted as the heating source.

Here, if the Vicat softening temperature of the second resin particles is higher than that of the first resin particles, peeling of the coating layer is suppressed by the fusion and coalescence according to the above method. In particular, the first resin particles and the second resin particles When the Vicat softening temperature difference of the resin particles is 10 ° C. or higher (desirably 10 ° C. or higher and 30 ° C. or lower, and the Vicat softening temperature of the second resin particles is 100 ° C. or lower), the coating layer easily peels off, This is effective because it is suppressed.
In addition, when adding value and functionalizing the obtained toner, a functional resin (for example, biomass resin) is applied as the first resin particles (first resin) constituting the core, and the basic toner In order to maintain characteristics (for example, chargeability in particular), it is preferable to apply a conventional binder resin (for example, a polyester resin or a styrene acrylic resin) as the second resin particles (second resin) constituting the coating layer, In this case, since the Vicat softening temperature of the first resin particles is higher than the Vicat softening temperature of the second resin particles, and the Vicat softening temperature difference is often 10 ° C. or more, peeling of the coating layer is likely to occur. This is effective because this is suppressed.

In addition, the measuring method of Vicat softening temperature is as follows.
A test piece having a prescribed size is set in the heating tub, and the temperature of the tub is raised in a state where an end surface of a constant cross-sectional area (1 mm ^{2 in} JIS K7206) is pressed to the center. The Vicat softening temperature is the temperature at which the end surface bites into the test piece to a certain depth (see JISK 7206).

  Through the above steps, the second resin (the first resin consisting of the first resin particles (the first resin in which the first resin particles are fused and united)) and the second resin (the second resin particles covering the core) ( A toner (core / shell structure toner) composed of a coating layer containing a second resin in which the second resin particles are fused and united) is obtained.

In addition, after completion | finish of a fusion | melting and uniting process, the toner of the state which dried the toner formed in the solution through a well-known washing process, a solid-liquid separation process, and a drying process is obtained.
In the washing step, it is preferable to sufficiently perform substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

Then, the resulting dried toner may be used as toner particles and an external additive may be added.
The addition of the external additive is preferably performed by, for example, a V blender, a Henshur mixer, a ladyge mixer or the like. Furthermore, if necessary, coarse toner particles may be removed using a vibration classifier, a wind classifier, or the like.

(Static image developing toner)
The electrostatic image developing toner according to the exemplary embodiment (hereinafter, simply referred to as “toner”) includes a core body that includes a first resin and a coating layer that covers the surface of the core body. And a coating layer including a second resin having a Vicat softening temperature higher than that of the first resin by 10 ° C. or more.

In the toner according to this embodiment, with the above-described configuration, 100% of the toner surface is controlled by the second resin while the fixing temperature and the viscoelasticity of the toner are controlled by the first resin that occupies 60% by mass or more of the entire toner. The chargeability can be determined exclusively, and conflicting characteristics such as high image quality and low power consumption are compatible.
As a result, the toner according to the exemplary embodiment becomes a toner for developing an electrostatic charge image with good storage stability.
The toner according to the exemplary embodiment is an electrostatic charge image developer. When applied to an image forming apparatus (process cartridge), the toner storage period is long, the surface property and the charge controllability are excellent, and a high-quality image can be obtained.

Here, the Vicat softening temperature difference between the first resin and the second resin is 10 ° C. or more, and desirably 10 ° C. or more and 30 ° C. or less.
The Vicat softening temperature of the second resin is higher than that of the first resin, but when adding value and functionalizing the obtained toner, it functions as the first resin particles (first resin) constituting the core. In order to maintain a basic characteristic (for example, chargeability) of the toner by applying a conductive resin (for example, biomass resin), a conventional binder resin (for example, second resin) constituting the coating layer (for example, A polyester resin, a styrene acrylic resin, or the like) is preferably applied. In this case, the Vicat softening temperature of the first resin particles is often higher than the Vicat softening temperature of the second resin particles.
In particular, when biomass resin is applied as the first resin particles (first resin) constituting the core and polyester resin or styrene acrylic resin is applied as the second resin particles (second resin) constituting the coating layer, The toner maintains basic characteristics (for example, chargeability) and has a reduced environmental load.

  Details of the electrostatic image developing toner will be described below.

The toner according to the exemplary embodiment includes a core body and a coating layer that covers the core body. Further, the toner according to the present embodiment may be configured so that toner particles are composed of a core body and a coating layer that covers the core body, and includes an external additive.
First, the core body will be described.
The core body includes, for example, a colorant, a release agent, and other additives as necessary together with the first resin as the binder resin.

The binder resin (first resin) may be selected from ordinary binder resins, but from the viewpoint of adding value and functionality to the toner, biomass resin, thermosetting resin, ultraviolet curable resin, Preferable examples include functional resins such as thermoplastic elastomers.
Biomass resin is a plant-derived polymer such as polylactic acid (PLA), polytrimethylene terephthalate (PTT), polybutylene succinate (PBS), phosphatidylglycerol (PG), isosorbite, acrylic acid-modified rosin, Cellulol, etc. are mentioned.
Thermosetting resins are phenol resin (PF), epoxy resin (EP), melamine resin (MF), urea resin (urea resin, UF), unsaturated polyester resin (UP), alkyd resin, polyurethane (PUR), heat Examples thereof include curable polyimide (PI).
The binder resin (first resin) may be used alone or in combination of two or more.

  As the binder resin (first resin), for example, a resin having a weight average molecular weight Mw of 1000 or more and 1000000 or less and a number average molecular weight Mn of 2000 or more and 80000 or less is preferably used.

The Vicat softening temperature of the binder resin (first resin) is preferably selected from, for example, 30 ° C. or higher and 150 ° C. or lower, preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 60 ° C. or higher and 75 ° C. or lower.
The Vicat softening temperature when two or more kinds of binder resins (first resins) are used in combination indicates the Vicat softening temperature in a mixed state.

  The colorant is not particularly limited as long as it is a known colorant. For example, carbon black such as furnace black, channel black, acetylene black, and thermal black, inorganic pigments such as bengara, bitumen, and titanium oxide, fast yellow, disazo Azo pigments such as yellow, pyrazolone red, chelate red, brilliant carmine, para brown, phthalocyanine pigments such as copper phthalocyanine, metal-free phthalocyanine, flavantron yellow, dibromoanthrone orange, perylene red, quinacridone red, dioxazine violet Examples thereof include cyclic pigments.

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

  As content of a coloring agent, the range of 1 to 30 mass parts is desirable with respect to 100 mass parts of binder resin.

  Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester types such as fatty acid esters and montanic acid esters. Wax; and the like, but is not limited thereto.

  The melting point of the release agent is preferably 50 ° C. or higher, and more preferably 60 ° C. or higher, from the viewpoint of storage stability. Further, from the viewpoint of offset resistance, the temperature is desirably 110 ° C. or less, and more desirably 100 ° C. or less.

  The content of the release agent is preferably 1% by mass or more and 15% by mass or less, more preferably 2% by mass or more and 12% by mass or less, and further more preferably 3% by mass or more and 10% by mass or less.

  Examples of other additives include magnetic materials, charge control agents, and inorganic powders.

Next, the clothing layer will be described.
The coating layer includes a second resin as a coating resin.

  The coating resin (second resin) is preferably selected from ordinary binder resins from the viewpoint of maintaining the basic characteristics (for example, chargeability) of the toner.

  Examples of ordinary binder resins include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, acrylic Esters having a vinyl group such as 2-ethylhexyl acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; vinyl nitriles such as acrylonitrile and methacrylonitrile; vinylmethyl Vinyl ethers such as ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, and vinyl isopropenyl ketone; and monomers such as polyolefins such as ethylene, propylene, and butadiene. Polymers or copolymers obtained by combining two or more of these, more mixtures thereof. In addition, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or a mixture of these with the vinyl resin, or vinyl monomers in the presence of these resins Examples thereof include a graft polymer obtained by polymerization.

Styrene resin, (meth) acrylic resin, and these copolymer resins are obtained by a well-known method, for example, combining a styrene-type monomer and a (meth) acrylic-type monomer individually or suitably. “(Meth) acryl” is an expression including both “acryl” and “methacryl”.
The polyester resin can be obtained by selecting and combining suitable ones from a polyvalent carboxylic acid and a polyhydric alcohol and synthesizing them using a conventionally known method such as a transesterification method or a polycondensation method.

When using a styrene resin, a (meth) acrylic resin, and a copolymer resin thereof as a binder resin, for example, the weight average molecular weight Mw is 20,000 to 100,000, and the number average molecular weight Mn is 2,000 to 30, It is good to use the thing of the range of 000 or less.
On the other hand, when a polyester resin is used as the binder resin, for example, those having a weight average molecular weight Mw of 5,000 to 40,000 and a number average molecular weight Mn of 2,000 to 10,000 are used. It is good.

Among these, polyester resin and styrene acrylic resin are preferable from the viewpoint of maintaining the basic characteristics (for example, chargeability) of the toner.
The binder resin (first resin) may be used alone or in combination of two or more.

The Vicat softening temperature of the coating resin (second resin) is preferably selected from, for example, 40 ° C. or more and 100 ° C. or less, and preferably 65 ° C. or more and 95 ° C. or less.
Note that the Vicat softening temperature when two or more kinds of coating resins (second resins) are used in combination indicates the Vicat softening temperature in a mixed state.

  The coating amount of the coating resin (second resin) on the core may be, for example, 10% or more and 25% or less with respect to the particle diameter after coating. 0.0 μm or less, more desirably 0.2 μm or more and 0.6 μm or less.

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

The surface of the external additive may be hydrophobized in advance. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, 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 about 1 part by mass or more and about 10 parts by mass with respect to 100 parts by mass of the inorganic particles, for example.

  The external addition amount of the external additive is preferably 0.5 parts by mass or more and 2.5 parts by mass or less with respect to 100 parts by mass of the toner particles.

Next, the characteristics of the toner (toner particles) will be described.
The volume average particle diameter of the toner (toner particles) is, for example, 4 μm or more and 15 μm or less, and desirably 5 μm or more and 10 μm or less.
As a method for measuring the volume average particle diameter of the toner (toner particles), 0.5 mg or more and 50 mg or less of a measurement sample is added to 2 ml of a 5% by weight aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant. This was added to 100 ml or more and 150 ml or less of the electrolytic solution. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the above-mentioned Coulter Multisizer II type (manufactured by Beckman-Coulter) is used to produce particles using an aperture having an aperture diameter of 100 μm. The particle size distribution of particles having a diameter in the range of 2.0 μm to 60 μm is measured. The number of particles to be measured is 50,000.
For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volume cumulative distribution is subtracted from the small particle size side, and the particle size that becomes 50% cumulative is defined as the volume average particle size D50v.

Next, a toner manufacturing method according to this embodiment will be described.
The toner according to the exemplary embodiment may be manufactured according to a well-known manufacturing method, but may be manufactured according to the toner manufacturing method according to the exemplary embodiment. Thereby, the toner in which the peeling of the coating layer is suppressed is obtained.

(Electrostatic image developer)
The electrostatic charge image developer according to the exemplary embodiment includes at least the toner according to the exemplary embodiment.
The electrostatic image developer according to this embodiment may be a one-component developer including only the toner according to this embodiment, or may be a two-component developer mixed with the toner and a carrier.

  There is no restriction | limiting in particular as a carrier, A well-known carrier is mentioned. Examples of the carrier include a resin-coated carrier, a magnetic dispersion carrier, a resin dispersion carrier, and the like.

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

(Image forming apparatus / image forming method)
Next, the image forming apparatus / image forming method according to the present embodiment will be described.
An image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and an electrostatic image development. A developing means for accommodating the developer and developing the electrostatic image formed on the image carrier as a toner image by the electrostatic image developer, and transferring the toner image formed on the image carrier onto the transfer target And a fixing unit that fixes the toner image transferred onto the transfer target. The electrostatic image developer according to the present embodiment is applied as the electrostatic image developer.

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

  The image forming method according to the present embodiment contains a charging step for charging the image carrier, an electrostatic charge image forming step for forming an electrostatic charge image on the surface of the charged image carrier, and an electrostatic charge image developer. A developing step of developing the electrostatic image formed on the image carrier as a toner image with an electrostatic charge image developer, and a transfer step of transferring the toner image formed on the image carrier onto the transfer target; And a fixing step of fixing the toner image transferred onto the transfer medium. And as the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. The main part shown in the figure will be described, and the description of other parts will be omitted.

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

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

  Since the first to fourth units 10Y, 10M, 10C, and 10K described above have the same configuration, here, the first image that forms the yellow image disposed on the upstream side in the intermediate transfer belt traveling direction is formed. The unit 10Y will be described as a representative. Note that the second to fourth components are denoted by reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y) in the same parts as the first unit 10Y. Description of the units 10M, 10C, and 10K will be omitted.

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

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

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

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

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

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

  The intermediate transfer belt 20 onto which the four color toner images have been transferred in multiple layers through the first to fourth units is arranged on the image transfer surface side of the intermediate transfer belt 20, the support roller 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer means) 26 is connected to a secondary transfer portion. On the other hand, the recording paper (transfer object) P is fed at a predetermined timing to the gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other via the supply mechanism, and the secondary transfer bias is supported. Applied to the roller 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, so The toner image is transferred onto the recording paper P. Note that the secondary transfer bias at this time is determined according to the resistance detected by a resistance detecting means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

  Thereafter, the recording paper P is sent to the pressure contact portions (nip portions) of the pair of fixing rolls in the fixing device (roll-type fixing unit) 28, and the toner image is fixed on the recording paper P, thereby forming a fixed image.

Examples of the transfer target to which the toner image is transferred include plain paper, OHP sheet, and the like used for electrophotographic copying machines and printers.
In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer object is as smooth as possible. For example, coated paper in which the surface of plain paper is coated with a resin or the like, art for printing Paper or the like is preferably used.

The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.
The image forming apparatus exemplified above is configured to transfer the toner image onto the recording paper P via the intermediate transfer belt 20, but is not limited to this configuration, and the toner image is directly transferred from the photoreceptor. It may be a structure that is transferred to a recording sheet.

<Process cartridge, toner cartridge>
FIG. 2 is a schematic configuration diagram showing an embodiment of a preferred example of a process cartridge containing an electrostatic charge image developer according to this embodiment. In the process cartridge 200, a charging roller 108, a developing device 111, a photoconductor cleaning device 113, an opening 118 for exposure, and an opening 117 for static elimination exposure are combined using a mounting rail 116 together with the photoconductor 107. , And integrated. In FIG. 2, reference numeral 300 denotes a transfer target.
The process cartridge 200 is detachable from an image forming apparatus including a transfer device 112, a fixing device 115, and other components not shown.

  The process cartridge 200 shown in FIG. 2 includes a charging device 108, a developing device 111, a cleaning device 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. Can be combined. In the process cartridge according to the present embodiment, in addition to the photosensitive member 107, the charging device 108, the developing device 111, the cleaning device (cleaning means) 113, the opening 118 for exposure, and the opening 117 for static elimination exposure. At least one selected from the group consisting of:

  Next, the toner cartridge according to this embodiment will be described. The toner cartridge according to the present exemplary embodiment is a toner cartridge that is detachably attached to the image forming apparatus and stores at least a replenishment electrostatic image developing toner to be supplied to a developing unit provided in the image forming apparatus.

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

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail more concretely, this embodiment is not limited to these Examples at all.

[Preparation of first resin particle dispersion]
(Biomass resin particle dispersion A1)
Biomass resin particle dispersion A1 was prepared as follows.
First, rosin (tall rosin) and fatty acids are separated from crude tall oil produced as a by-product when producing kraft pulp from pine. This tall rosin is purified and adjusted to a number average molecular weight: Mn of 3000 to 8000 / acid value AV: 1 mg / KOH to 40 mg / KOH.
Next, in a 2 L separable flask equipped with a stirring blade, a condenser, a thermometer, and a water dropping device, 300 parts by mass of the adjusted rosin, 105 parts by mass of methyl ethyl ketone (solvent), and 90 parts by mass of isopropyl alcohol (solvent) were added. The mixture was heated to 70 ° C. with a hot water bath, maintained at 70 ° C., and the resin was dissolved while stirring and mixing at 100 rpm (dissolution preparation step).
Thereafter, the stirring rotation speed was set at 150 rpm, the hot water bath was set at 66 ° C., and the mixture was left for 30 minutes to stabilize the temperature.
Next, 15 parts by mass of 10% by mass aqueous ammonia (reagent) was added in 1 minute, mixed for 10 minutes, and then ion-exchanged water kept at 66 ° C. at a rate of 7 parts by mass / min. It was dropped and phase-inverted to obtain an emulsion. Immediately after completion of the dropwise addition of water, the mixture was cooled to 25 ° C. in a 20 ° C. water bath.

Next, 800 parts by mass of the cooled emulsion and 500 parts by mass of ion-exchanged water were placed in a 2 L eggplant flask and set in an evaporator (manufactured by Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball.
Next, while rotating the eggplant flask, heating was performed at 60 ° C. for 30 minutes in a hot water bath to stabilize the liquid temperature, and then pressure reduction was started. The depressurization condition is the capacity limit speed of the pump from 101 kPa to 50 kPa, depressurize from 50 kPa to 7 kPa in 172 minutes, maintain 7 kPa after reaching 7 kPa, and adjust the degree of vacuum appropriately so that the contents do not bump during the process. The solvent was recovered. When the solvent recovery amount reaches 850 parts by mass, the pressure is returned to normal pressure, the eggplant flask is cooled with water, and a biomass resin particle dispersion having a volume average particle size of 180 nm (Horiba, Laser diffraction particle size measuring device: LA920: the same applies below). A1 was obtained.
Ion exchange water was added to the obtained dispersion to adjust the solid content concentration to 30% by mass.

(Polystyrene resin particle dispersion A2)
Polystyrene resin particle (= thermosetting resin particle) dispersion A2 was prepared as follows.
First, in a 2 liter flask equipped with a reflux condenser, 133 g of distilled water, nonionic surfactant Eleminol NL-100 (Polyoxyethylene alkyl ether manufactured by Sanyo Chemical Industries, HLB value = 14, cloud point = 90 ° C.) 0.53 g (= 3.2 wt% with respect to styrene) was sampled, and nitrogen gas was blown into the water while stirring at 600 rpm, replacing oxygen dissolved in the water over about 30 minutes.
Next, the temperature was raised to 85 ° C. under a nitrogen gas stream, 17 g of styrene, 1.3 g of hexanediol acrylate (= 3.5 mol% with respect to styrene), and 0.01 g of acrylic methacrylate (= 0.00% with respect to styrene). 02 mol%) was added.
Next, an aqueous solution in which potassium persulfate 0.62 (= 3.7 wt% with respect to styrene) was dissolved in 17 g of water was added, and emulsion polymerization was carried out by maintaining the same temperature for 1 hour. At this time, the polymerization rate became 100%, and the emulsion polymerization was almost stopped, and a polystyrene resin particle dispersion A2 (solid content concentration 42.9% by mass) was obtained. A part of the dispersion (about 0.8 ml) was taken out and the volume average particle diameter was examined.
The obtained dispersion was adjusted to a solid content concentration of 40% by mass while maintaining the dispersed state of the resin particles by dilution and concentration operations.

(Polyester resin particle dispersion A3)
Polyester resin particle dispersion A3 was prepared as follows.
First, in a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, dimethyl terephthalate 23 mol%, isophthalic acid 10 mol%, dodecenyl succinic anhydride 15 mol%, trimellitic anhydride 3 mol%, bisphenol A 5 mol% of ethylene oxide adduct and 45 mol% of bisphenol A propylene oxide adduct were added, and the reaction vessel was replaced with dry nitrogen gas, and then added as a catalyst at a rate of 0.06 mol% of dibutyltin oxide, and a nitrogen gas stream The reaction was stirred at about 190 ° C. for about 7 hours.
The temperature was further raised to about 250 ° C., and the reaction was stirred for about 5.0 hours, and then the pressure in the reaction vessel was reduced to 10.0 mmHg and the reaction was stirred for about 0.5 hours under reduced pressure to obtain a polyester resin. The polyester resin obtained had a glass transition point (Tg) of 55 ° C. Moreover, the weight average molecular weight (Mw) was 21200, and the acid value of resin was 15 mgKOH / g.

160 parts by mass of the obtained polyester resin, 640 parts by mass of ion-exchanged water, and 8.0 parts by mass of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK; 20% by mass) are predispersed and pH is adjusted with ammonia. Was adjusted to 7.5. Next, using a disperser in which Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) is remodeled into a high-temperature and high-pressure type, dispersion is performed under the conditions of a rotor rotation speed of 60 Hz, a pressure of 5 kg / cm ² , and heating by a heat exchanger at 140 ° C. A polyester resin particle dispersion A3 (solid content concentration 20% by mass) having a volume average particle diameter of 160 nm was obtained.

(Styrene acrylic resin particle dispersion A4)
Styrene acrylic resin particle dispersion A4 was prepared as follows.
First, 370 parts by mass of styrene, 30 parts by mass of n-butyl acrylate, 8 parts by mass of acrylic acid, 24 parts by mass of dodecanethiol, and 4 parts by mass of carbon tetrabromide were mixed and dissolved in a nonionic surfactant ( Nonipol 400: Sanyo Chemical Co., Ltd.) 6 parts by mass and anionic surfactant (Neogen SC: Daiichi Kogyo Seiyaku Co., Ltd.) 10 parts by mass in ion-exchanged water 550 parts by mass in a flask. While slowly mixing for 10 minutes, 50 parts by mass of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added thereto. After performing nitrogen substitution, the contents in the flask were stirred and heated in an oil bath until the content reached 70 ° C., and emulsion polymerization was continued for 5 hours. Styrene having a volume average particle size of 170 nm and a solid content concentration of 35% Acrylic resin particle dispersion A4 was obtained.

[Preparation of second resin particle dispersion]
(Biomass resin particle dispersion B1)
The biomass resin particle dispersion B1 was prepared according to the same formulation as the biomass resin particle dispersion A1.
The obtained dispersion had a volume average particle diameter of resin particles of 180 nm and a solid content concentration of 30% by mass.

(Polystyrene resin particle dispersion B2)
Polystyrene resin particle (= thermosetting resin particle) dispersion B2 was prepared with the same formulation as polystyrene resin particle dispersion A2.
The obtained dispersion had a volume average particle size of resin particles of 330 nm and a solid content concentration of 40% by mass.

(Polyester resin particle dispersion B3)
Polyester resin particle dispersion B3 was prepared with the same formulation as polyester resin particle dispersion A3.
The obtained dispersion had a volume average particle size of resin particles of 180 nm and a solid content concentration of 20% by mass.

(Polyester resin particle dispersion B4)
Styrene acrylic resin particle dispersion B4 was prepared with the same formulation as styrene acrylic resin particle dispersion A4.
The resulting dispersion had a volume average particle diameter of 170 nm of resin particles and a solid content concentration of 35% by mass.

[Preparation of colorant particle dispersion]
-Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika Co., Ltd.) 45 parts by mass-Ionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by mass-200 parts by mass of ion-exchanged water Then, it was dispersed for 10 minutes by a homogenizer (IKA Ultra Tarrax) to obtain a colorant particle dispersion having a center particle size of 140 nm and a solid content of 22.0 parts by mass.

[Preparation of release agent particle dispersion]
Paraffin wax HNP9 (melting point 75 ° C .: manufactured by Nippon Seiki Co., Ltd.) 45 parts by mass Cationic surfactant Neogen RK (produced by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by mass 200 parts by mass of ion-exchanged water The mixture was heated and dispersed with IKA Ultra Turrax T50, and then dispersed with a pressure discharge type gorin homogenizer to obtain a release agent particle dispersion having a center particle size of 200 nm and a solid content of 20.0 parts by mass.

[Example 1]
-First aggregated particle forming step-
First resin particle dispersion (biomass resin particle dispersion A1): 278.9 parts by mass Colorant particle dispersion: 27.3 parts by weight Release agent particle dispersion: 35 parts by weight The above components are round glass In the flask, the mixture was mixed and dispersed with Ultra Turrax T50. Subsequently, 0.20 part by mass of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. While stirring the flask in a heating oil bath, the flask was heated to 48 ° C. to aggregate each particle.

-Second aggregated particle forming step-
Then, after being held at 48 ° C. for 60 minutes, when the volume average particle size of the first aggregated particles reaches 5.0 μm, the second resin particle dispersion (styrene / acrylic resin particle dispersion) is placed in the round stainless steel flask. 70.0 parts by mass of the liquid B4) was added to aggregate the second resin particles.
Thereafter, the pH in the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution to stop aggregation.

-Fusion / unification process-
Then, the glass flask is sealed, and microwaves are irradiated from the side of the glass flask while continuing the stirring (condition: output 600W, irradiation time 10 sec, intermittent method in which intermittent time 10 seconds are alternately repeated), and the heating rate is 1 ° C. The second resin particles (resin particles of styrene / acrylic resin particle dispersion B4) were heated to + 10 ° C. + 10 ° C. and held for 1 minute.

-Post process-
After completion of the reaction, the mixture was cooled, filtered, washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 30 ° C., and stirred and washed at 300 rpm for 15 minutes.
This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Next, vacuum drying was continued for 12 hours to obtain a core / shell toner (toner particles).

  Then, 1 part by mass of silica particles (R972 (manufactured by Nippon Aerosil Co., Ltd.)) is added to 100 parts by mass of the toner (toner particles) having a core / shell structure, and 15 minutes at a peripheral speed of 30 m / s using a 5-liter Henschel mixer. After blending, coarse particles were removed using a sieve having an opening of 45 μm to prepare an externally added toner.

[Example 2]
Second agglomerated particles were produced by the same production method up to the “second agglomerated particle forming step” in Example 1.
Then, after the glass flask containing the second aggregated particle dispersion is transferred to a thermostatic bath with a magnetic stirrer maintained at 48 ° C., the second aggregated particle dispersion is stirred with a magnetic stirrer, and a curved pipe (tube) A micro heat exchanger with a diameter of Φ1 mm and a length of 10 m) embedded in a constant temperature bath was continuously rapidly heated so that the second agglomerated particle dispersion was 90 ° C. in a curved pipe, and then placed in a water cooling bath It moved to the other glass flask which entered, and ice-cooled (refer FIG. 6).
The two glass flasks are connected to the curved pipe of the micro heat exchanger by piping, and the second aggregated particle dispersion is supplied from the one glass flask through the piping and the curved pipe by a suction pump. The product was passed through at 10 mim (made in-house: manufactured according to the description in JP-A-2009-147016) and sucked so as to be moved to another glass flask.
As a result, a fusion / unification process was performed, and then a post-process was performed in the same manner as in Example 1 to obtain a toner (toner particles) having a core / shell structure.
In addition, it was confirmed from the evaluation result of Example 1 and 2 mentioned later that it is a desirable heating method.

[Examples 3 to 5, Comparative Example 1]
Example 1 except that the irradiation conditions of the first resin particle dispersion, the second resin particle dispersion, and the microwave were adjusted according to Table 1, or the heating conditions in the fusion / unification process were changed by other heating means. Each toner was prepared in the same manner as described above.

[Evaluation 1]
The following evaluation was performed on the toner obtained in each example. The results are shown in Table 2.

-Surface observation-
The surface of the toner (toner particles before the addition of the external additive) obtained in each example was observed by SEM, and the state of peeling of the coating layer was evaluated.

-Measurement of volume average particle diameter and GSD-
The volume average particle diameter and GSDv of the toner (toner particles before addition of external additives) obtained in each example were examined.
Note that GSDv, which is an index of volume particle size distribution, is obtained by the equation “GSDv = (D84v / D16v) ^1/2 ”. Here, in the method for measuring the volume average particle diameter of the toner (toner particles) described above, D84v is a particle diameter value that is 84% cumulative from the small diameter side in the volume distribution of the particle diameter, and D16v is the volume distribution of the particle diameter. Is a particle size value of 16% cumulative from the small diameter side.
D16v and D84v were measured with a Coulter Multisizer IV (manufactured by Beckman Coulter).

[Evaluation 2]
For the toner obtained in each example (toner after addition of external additives), the minimum fixing temperature (MFT), the gloss of the fixed image, the biomass degree, the pot life (storage stability) average circularity, and the charge amount are evaluated. It was. The results are shown in Table 3.
Specifically, 23 ° C. and 50% R.I. H. Under the above conditions, 30 parts by mass of toner and 800 parts by mass of ferrite carrier (EPT1000 manufactured by Toda Kogyo Co., Ltd.) were put into a polybin, and mixed uniformly by hand to obtain a two-component developer for evaluation.
Using these developers, the temperature of the fixing device of a commercially available copying machine (DocuColor 450) was variably modified, and a fixed image was produced.
The gloss of the fixed image was measured with Gloss Meter GM-26D (Murakami Color Engineering Laboratory), and the incident angle of light with respect to the image was 75 degrees. The glossiness was evaluated using a cyan image with an output of 100%. Glossiness S / W is “◯” when the difference in glossiness (100%) is 30 or more between @ -1 to @ -4, “△” when 20 or more and less than 30, and “X” when less than 20. ”Was evaluated in three stages.

  The fixing roll temperature at which the remaining ratio of the fixed image after rubbing with a pad becomes 70% or more was defined as the “minimum fixing temperature”. The lower the minimum fixing temperature, the better the low temperature fixing property.

  On the other hand, the biomass degree of the obtained toner was calculated from the concentration of biomass raw materials and the biomass component ratio.

  Further, the pot life (storage stability) of the obtained toner was allowed to stand for 48 hours at high temperature and high humidity (temperature 28 ° C., humidity 85%), and evaluated by the degree of toner aggregation. “○” was given only when no toner was present, “△” was given for the state where it could be used as a toner, although there was some aggregation, and “x” for other cases.

Further, the average circularity of the obtained toner was determined using FPIA-3000 manufactured by Sysmex.
FPIA-3000 employs a method of measuring particles dispersed in water or the like by a flow-type image analysis method. The suctioned particle suspension is guided to a flat sheath flow cell, and a flat sample flow is produced by the sheath liquid. Form. By irradiating the sample stream with strobe light, the passing particles are imaged with respect to at least 5000 toners as a still image by the CCD camera through the objective lens. The captured particle image is subjected to two-dimensional image processing, and the equivalent circle diameter is calculated from the projected area and the perimeter. The equivalent circle diameter is calculated as the equivalent circle diameter from the area of the two-dimensional image for each photographed particle.
Here, the circularity can be obtained by the following equation (1).
Formula (1): Circularity = circle equivalent diameter circumference length / circumference length = [2 × (A × π) ^1/2 ] / PM
(In the above formula, A represents the projected area and PM represents the perimeter.)
The average circularity can be obtained by calculating and averaging these for each particle.

  The charge amount of the obtained toner was measured with a CSG (charge spectrograph) in an environment where the temperature was 28 ° C. and the humidity was 85%, and the charge amount (μC / g) was calculated by image analysis of the CSG.

  According to a comparison between Example 1 and Comparative Example 1, even in a system in which the Vicat softening temperature with the second resin (second resin particle) is higher than that of the first resin (first resin particle), the coating layer does not peel off and the toner It can be seen that particles were obtained.

In Example 3, it is understood that the gloss is improved under a more preferable condition by changing the temperature raising condition by the microwave.
It can be seen from Examples 4 and 5 that the pot life is improved when the difference in the bigat softening point is 10 ° C. or more.
From Example 5, it can be seen that when the difference in the bigat softening point is 5 ° C. or more, the degree of biomass is improved.
In any of the examples, while maintaining the gloss at a high level, the chargeability is controlled in the range of 40 or more and the circularity is in the range of 0.95 or more and 0.99 or less. It can be seen that the gloss of the image was adjusted even with a moderate MFT.
As a result, it can be seen that high image quality is achieved in any of the embodiments.

1Y, 1M, 1C, 1K, 107 photoconductor (latent image holder)
2Y, 2M, 2C, 2K, 108 Charging roller 3Y, 3M, 3C, 3K Laser beam 3 Exposure device 4Y, 4M, 4C, 4K, 111 Developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer rollers 6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller (transfer means)
28, 115 Fixing device (fixing means)
30 Intermediate transfer member cleaning device 112 Transfer device 116 Mounting rail 117 Opening portion 118 for static elimination exposure Opening portion 200 for exposure Process cartridge P, 300 Recording paper (transfer object)

Claims (9)

A first aggregated particle forming step of preparing at least a first resin particle dispersion in which the first resin particles are dispersed, aggregating at least the first resin particles to form first aggregated particles;
Mixing the first aggregated particle dispersion in which the first aggregated particles are dispersed and the second resin particle dispersion in which the second resin particles having a higher Vicat softening temperature than the first resin particles are dispersed, A second aggregated particle forming step of aggregating the second resin particles so as to adhere to the surface of the first aggregated particles to form second aggregated particles;
The second aggregated particle dispersion in which the second aggregated particles are dispersed is heated at a temperature rising rate of 0.5 ° C./sec or more and above the Vicat softening temperature of the second resin particles, A fusion and coalescence process for fusing and coalescing the agglomerated particles;
A method for producing a toner for developing an electrostatic charge image.   In the fusion and coalescence step, the heating rate from the start of heating until reaching the Vicat softening temperature of the first resin particles, and the heating rate after reaching the Vicat softening temperature of the second resin particles, 2. The electrostatic charge image developing toner according to claim 1, wherein the heating is performed by increasing a temperature rising rate from reaching the Vicat softening temperature of the second resin particles after reaching the Vicat softening temperature of the first resin particles. Production method. A core composed of a first resin;
A coating layer covering the surface of the core body, the coating layer including a second resin having a Vicat softening temperature higher by 10 ° C. or more than the first resin;
A toner for developing an electrostatic charge image.   The electrostatic charge image development according to claim 3, wherein the first resin constituting the core is a biomass resin, and the second resin constituting the coating layer is at least one selected from a polyester resin and a styrene acrylic resin. Toner.   An electrostatic charge image developer comprising at least the electrostatic charge image developing toner according to claim 3. Containing the toner for developing an electrostatic image according to claim 3 or 4;
A toner cartridge to be attached to and detached from the image forming apparatus. A developing means for accommodating the electrostatic charge image developer according to claim 5 and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus. An image carrier,
Charging means for charging the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Developing means for containing the electrostatic charge image developer according to claim 5 and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the image carrier onto a transfer target;
Fixing means for fixing the toner image transferred onto the transfer medium;
Image forming apparatus comprising A charging step for charging 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 containing the electrostatic charge image developer according to claim 5 and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer;
A transfer step of transferring a toner image formed on the image carrier onto a transfer target;
A fixing step of fixing the toner image transferred onto the transfer medium;
An image forming method comprising:

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