JP6693201B2 - Toner for developing electrostatic latent image and image forming method - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic latent image. More specifically, the present invention relates to an electrostatic latent image developing toner that improves low-temperature fixability and suppresses fluctuations in image glossiness while preventing contamination in the image forming apparatus.

2. Description of the Related Art In recent years, electrophotographic image forming apparatuses have been required to have higher speeds, higher image quality, and expanded applications, and electrostatic latent image developing toners (hereinafter also simply referred to as “toners”) used therefor are also required to have such requirements. Toners that can meet the demands of the market are being developed.
From the viewpoint of preventing global warming of the global environment, there is an increasing demand for energy saving in electrophotographic image forming apparatuses, and development of low-temperature fixing toner capable of fixing with a small amount of energy is underway.

  As a typical study for lowering the fixing temperature of the toner, there is one using a crystalline material. In addition, when low temperature fixing property is pursued, it tends to be melted by heat, so that heat resistant storage property may become a problem. Therefore, development of a toner using an amorphous polyester resin as a main binder resin, which can achieve both low-temperature fixing property and heat-resistant storage property at a high level, is underway.

For example, Patent Document 1 discloses a toner containing a crystalline polyester resin and a releasing agent, and a structure in which the crystalline resin polyester resin is in contact with the releasing agent is present in the ruthenium-stained toner cross section. Letting A be the cross-sectional area of the structure, B be the cross-sectional area of the release agent alone, and C be the cross-sectional area of the crystalline resin polyester resin alone, 40 ≦ 100 × A / (A + B + C) ≦ 70, 10 There is described an electrostatic charge developing toner characterized in that ≦ 100 × B / (A + B + C) ≦ 30 and 20 ≦ 100 × C / (A + B + C) ≦ 30.
The above-mentioned document does not mention the recrystallization behavior of the crystalline polyester resin and the release agent when the cooling rate of the image is changed, and there is a problem that it is difficult to prevent the fluctuation of the glossiness of the image.

Further, in Patent Document 2, in a toner using at least a crystalline polyester Ac and an amorphous polyester Aa, the amorphous polyester Ba and the crystalline polyester Bc are reacted so that the ends become crystalline polyester segments. A copolymer B is further included, and the dispersion diameter of the crystalline polyester domain in the toner is 1.0 μm or less.
Although the above-mentioned document finely disperses a crystalline polyester (hereinafter, also referred to as "CPES") to prevent the toner from being exposed to the toner surface, the presence state of the release agent and CPES is not controlled, and fixing is performed. There was a problem that the exudation of wax in the process could not be sufficiently controlled and contamination inside the machine occurred.

JP, 2008-33057, A JP, 2015-176111, A

  The present invention has been made in view of the above problems and circumstances, and a problem to be solved by the invention is to improve low-temperature fixability while preventing contamination in an image forming apparatus, and to suppress fluctuations in glossiness of an image. To provide a latent image developing toner. Another object of the present invention is to provide an image forming method using the electrostatic latent image developing toner.

MEANS TO SOLVE THE PROBLEM As a result of examining the cause of the said problem in order to solve the said subject, the electrostatic latent image developing toner of this invention isolate | separated with the binder resin containing an amorphous polyester resin and a crystalline resin, and. A toner for developing an electrostatic latent image containing toner base particles containing at least a mold agent, wherein the amorphous polyester resin is a main component of a binder resin, and the toner base particles have at least a crystalline structure. The present invention has been found to have three types of regions having different states, to improve the low-temperature fixability while suppressing contamination in the low-image forming apparatus, and to suppress fluctuations in the glossiness of the image, leading to the present invention.
That is, the said subject of this invention is solved by the following means.

1. A toner for electrostatic latent image development comprising toner base particles containing at least a binder resin containing an amorphous polyester resin and a crystalline resin, and a release agent,
The toner base particles are particles formed by aggregating and fusing particles of the amorphous polyester resin, particles of the crystalline resin, and particles of the release agent,
The amorphous polyester resin is the main component of the binder resin,
As the crystalline resin, a crystalline polyester polymerized segment and an amorphous polyester polymerized segment are at least chemically bound, a hybrid crystalline polyester resin, and a non-hybrid crystalline polyester resin, respectively, the binder resin and the The release agent is contained in the range of 2.75 to 7.5 parts by mass with respect to 100 parts by mass in total,
As the release agent, an ester wax and a paraffin wax are contained in the range of 3.0 to 12.5 parts by mass with respect to 100 parts by mass of the total amount of the binder resin and the release agent, respectively.
The toner base particles have a matrix region containing the amorphous polyester resin, and a domain region that exists in the matrix region in an isolated and dispersed manner.
The domain area, said the area crystalline resin and said release agent is contained structure in contact (A), the releasing agent filamentous crystals exist independently without contacting the A region (B) containing a crystalline resin forming a structure and a region (C) containing a crystalline resin forming a lamellar crystal structure independently existing without contact with the release agent (C). ) And a region (D) containing a release agent which independently exists without contacting the crystalline resin,
The toner in the area (A) of the total of the area (A + B + C) containing the crystalline resin and the area (D) containing the release agent which independently exists without contacting the crystalline resin. A toner for developing an electrostatic latent image, characterized in that a ratio (A / (A + B + C + D)) in the cross-sectional area of the base particles is within a range of 0.30 to 0.95 .

2 . The toner for developing an electrostatic latent image according to item 1, wherein the average major axis of the region (B) is within a range of 200 to 2000 nm.

3 . The toner for developing an electrostatic latent image according to item 1 or 2, wherein the average domain diameter of the region (A) is within a range of 200 to 2500 nm.

4 . The toner for developing an electrostatic latent image according to any one of items 1 to 3, wherein an average domain diameter of the region (C) is within a range of 100 to 2000 nm.

5 . The toner in the area (A) of the total of the area (A + B + C) containing the crystalline resin and the area (D) containing the release agent which independently exists without contacting the crystalline resin. The ratio (A / (A + B + C + D)) in the cross-sectional area of the base particles is in the range of 0.35 to 0.90, wherein the static amount according to any one of items 1 to 4 Toner for developing electrostatic latent images.

6 . An electrostatic latent image image is formed by using the electrostatic latent image developing toner according to any one of items 1 to 5 .

  By the above means of the present invention, it is possible to provide a toner for developing an electrostatic latent image, which improves low-temperature fixability while suppressing contamination in the image forming apparatus and suppresses fluctuation in glossiness of an image. Further, it is possible to provide an image forming method using the electrostatic latent image developing toner.

The mechanism of action or mechanism of action of the present invention has not been clarified, but is presumed as follows.
As described above, when amorphous resin is used as the main component (matrix resin) of the binder resin to form a domain by introducing a crystalline resin for the purpose of improving low temperature fixability, the crystalline resin has a melting point. Since it is compatible with the matrix resin in the vicinity, it is known that the fixing property can be improved while maintaining the heat resistant storage stability of the toner.
However, as the binder resin is softened, toner deformation in the fixing nip is promoted, so that the exudation of the release agent becomes excessive and the fixing member may be contaminated. Therefore, by allowing a part of the crystalline resin to exist as a crystalline resin-release agent structure to control the exudation of the release agent, the low temperature fixability is improved and the contamination in the image forming apparatus is prevented. I think it can be suppressed.

When the crystalline resin is present in the toner base particles, the crystalline resin domains are formed and grow in the image layer formed on the paper, and the domains grow and grow while the image after fixing is cooled. When formed, there is a problem in that the deformation of the image surface is induced and the glossiness changes.
In particular, when a toner containing an amorphous polyester resin as a main component is used, the crystalline resin tends to adapt to the amorphous polyester resin, and the recrystallization rate tends to be slow, and the cooling rate of the image after fixing may be low. When it changed, the change in gloss was remarkable.

Therefore, a thread-like crystal structure is formed at a relatively high temperature at the beginning of cooling, and the crystalline resin compatible with the binder resin is deposited. As a result, softening due to plasticization of the binder resin is eliminated and the viscosity is increased. Then, a lamellar crystal structure and a crystalline resin-wax structure are formed by domain growth of the crystalline resin. Since the viscosity of the binder resin at this time is high, the unevenness generated by domain growth does not reach the image surface, and the gloss does not change.
Further, since the lamellar crystal structure and the crystalline resin-releasing agent structure coexist, a part of the releasing agent remains inside the toner layer and appropriately permeates to the toner layer surface. There is no excessive glare in the image part.
That is, the toner for electrostatic latent image development contains toner base particles having a region containing a crystalline resin forming a thread-like crystal structure and a lamellar crystal structure and a region containing a crystalline resin-wax structure. Therefore, it is considered that the toner for electrostatic latent image development can be provided in which the low temperature fixing property is improved while preventing the contamination in the image forming apparatus and the fluctuation of the glossiness of the image is suppressed.

Schematic diagram showing the cross section of toner base particles Schematic diagram showing an example of an image forming apparatus

The toner for developing an electrostatic latent image of the present invention is a toner for developing an electrostatic latent image containing toner base particles containing at least a binder resin containing an amorphous polyester resin and a crystalline resin, and a release agent. There
The toner base particles are particles formed by aggregating and fusing particles of the amorphous polyester resin, particles of the crystalline resin, and particles of the release agent,
The amorphous polyester resin is the main component of the binder resin,
As the crystalline resin, a crystalline polyester polymerized segment and an amorphous polyester polymerized segment are at least chemically bound, a hybrid crystalline polyester resin, and a non-hybrid crystalline polyester resin, respectively, the binder resin and the The release agent is contained in the range of 2.75 to 7.5 parts by mass with respect to 100 parts by mass in total,
As the release agent, an ester wax and a paraffin wax are contained in the range of 3.0 to 12.5 parts by mass with respect to 100 parts by mass of the total amount of the binder resin and the release agent, respectively.
The toner base particles have a matrix region containing the amorphous polyester resin, and a domain region that exists in the matrix region in an isolated and dispersed manner.
The domain area, said the area crystalline resin and said release agent is contained structure in contact (A), the releasing agent filamentous crystals exist independently without contacting the A region (B) containing a crystalline resin forming a structure and a region (C) containing a crystalline resin forming a lamellar crystal structure independently existing without contact with the release agent (C). ) And a region (D) containing a release agent which independently exists without contacting the crystalline resin,
The toner in the area (A) of the total of the area (A + B + C) containing the crystalline resin and the area (D) containing the release agent which independently exists without contacting the crystalline resin. The ratio (A / (A + B + C + D)) in the cross-sectional area of the base particles is in the range of 0.30 to 0.95 .
This feature is a technical feature common to or corresponding to the claimed invention.

  In an embodiment of the present invention, the crystalline resin preferably contains a crystalline polyester resin. This is because the crystalline polyester resin is easy to control the melting temperature and the crystal structure, and melts when the toner is heated to be compatible with the amorphous polyester resin, which has the effect of softening the amorphous polyester resin.

  Further, when the average major axis of the region (B) is in the range of 200 to 2000 nm, the compatibility with the binder resin can be adjusted, and the crystals are crystallized even when stored in a high temperature and high humidity environment. Since it is possible to minimize the unevenness caused by growth, it is more preferable in that an image can be formed with stable image quality.

  Further, when the average domain diameter of the region (A) is in the range of 200 to 2500 nm, the toner melts and the deformation proceeds, so that excellent low-temperature fixability is exhibited, and the exudation amount of the release agent is optimal. This range is preferable because the difference in gloss can be minimized.

  In addition, when the average domain diameter of the region (C) is within the range of 100 to 2000 nm, the toner melts and the deformation proceeds, so that excellent low-temperature fixability is exhibited and the toner is stored in a high-temperature and high-humidity environment. Even if there is, unevenness caused by crystal growth can be minimized, which is preferable in that an image can be formed with stable image quality.

  In addition, the crystalline resin contains a hybrid crystalline polyester resin in which a crystalline polyester polymerized segment and an amorphous polyester polymerized segment are at least chemically bound, due to the folding of the molecular chain of the lamellar crystal structure. It is preferable because the thickness can be increased to some extent (that is, the crystallinity can be increased), and the aspect ratio of the lamellar crystal structure and the thickness of the lamellar crystal structure can be easily controlled within a predetermined range.

  In addition, of the total of the region (A + B + C) containing the crystalline resin and the region (D) containing the release agent which independently exists without contacting the crystalline resin, the region (A) When the ratio (A / (A + B + C + D)) in the cross-sectional area of the toner base particles is in the range of 0.35 to 0.90, the fixing member is not contaminated with the releasing agent and the releasing agent is Since the areas (A) to (C) are appropriately exuded to form the areas (A) to (C), it is preferable in that the fluctuation of the glossiness of the image can be suppressed.

  In addition, the crystalline resin, a crystalline polyester polymerized segment and an amorphous polyester polymerized segment at least chemically bound, a hybrid crystalline polyester resin, and containing a non-hybrid crystalline polyester resin, crystalline The polyester resin is preferable because it is possible to control the compatibility with the amorphous polyester resin that is the matrix resin and to adjust the existing state of the crystalline polyester resin.

  In addition, it is preferable that the release agent contains an ester wax because the formation of the structure of the release agent and the crystalline polyester resin can be promoted and the existing state of the structure can be adjusted.

  It is preferable that the mold release agent contains paraffin wax because the structure of the mold release agent and the crystalline polyester resin is not formed so that the existing state of the structure can be adjusted.

  It is preferable that the toner base particles contain the metal element at a metal concentration within the range of 20 to 2000 mass ppm because the effect of low temperature fixability can be obtained without excessively increasing the amount of crosslinking by ionic bonds.

  Since the metal concentration is preferably a metal element derived from an aggregating agent used in the production of toner, it is derived from at least one metal element selected from aluminum (Al), magnesium (Mg) and iron (Fe). It is preferably a metal concentration.

  It is preferable to form an electrostatic latent image by using the electrostatic latent image developing toner of the present invention from the viewpoint of manifesting the effects of the present invention.

  The member in contact with the fixing surface in the fixing step is composed of a plurality of layers, and the thickness of the elastic layer of the plurality of layers is in the range of 50 to 300 μm. It is preferable because the adhesion to the toner layer is increased, the heat conduction to the toner layer is promoted, the toner melting is promoted, and the surface of the layer formed by melting the toner is uniformly smoothed.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, "-" shown in the following description is used to mean that the numerical values described before and after the "-" are included as the lower limit value and the upper limit value.

[Overview of toner for electrostatic latent image development]
The toner for developing an electrostatic latent image of the present invention is a toner for developing an electrostatic latent image containing toner base particles containing at least a binder resin containing an amorphous polyester resin and a crystalline resin, and a release agent. The amorphous polyester resin is a main component of a binder resin, and the toner base particles contain a structure in which the crystalline resin and the release agent are in contact with each other ( A) and a region (B) containing a crystalline resin that forms a thread-like crystal structure that exists independently without contact with the release agent, and independently with no contact with the release agent. And a region (C) containing a crystalline resin forming a lamella-like crystal structure that is present as an existing structure.

Specifically, as shown in FIG. 1, it can be seen that the cross section of the toner base particles contains the crystalline resin 1, the release agent 2 and the amorphous polyester resin 6.
The crystalline resin contained in the toner base particles contains a region (a structure in which the crystalline resin and the release agent are in contact) formed in contact with the release agent ( A) 3, a region (B) 4 containing a crystalline resin that forms a thread-like crystal structure that exists independently without contact with a release agent, and a lamellar shape that is not in contact with the release agent There is a region (C) 5 containing a crystalline resin having a crystal structure.

Here, the thread-like crystal structure is a crystal structure in which a crystalline resin is formed by folding of molecular chains without being crystallized, and means a thread-like crystal structure composed of one or several molecular chains.
The structure in which the crystalline resin and the release agent are in contact with each other means a structure in which the crystalline resin and the release agent are in contact with each other even at one point.
Further, the lamellar crystal structure represents a layered structure produced by crystallization due to folding of the molecular chain of the crystalline resin.

(Toner cross-section observation)
Although details will be described in Examples, a cross-section of the toner can be observed, and the three regions can be confirmed.

[Average domain diameter]
The “average domain diameter” is a continuous phase (matrix) of the resin component forming the toner base particles, and is, for example, an island-like or particle-like area that is isolated / dispersed by a method described later. The average value of the obtained ferret diameter.
That is, "the average domain diameter of the region (A) containing the structure in which the crystalline resin and the release agent are in contact" means that the crystalline resin 1 and the release agent 2 shown in FIG. The Feret diameter of the region (A) 3 surrounded by the dotted line and containing the structure thus formed.
Similarly, "the average domain diameter of the region (B) containing the crystalline resin that forms a thread-like crystal structure that exists independently without contacting with the release agent" means the thread-like crystals shown in FIG. The average value of the Feret diameter of the region (B) 4 surrounded by the solid line and containing the crystalline resin forming the structure.
"The average domain diameter of the region (C) containing a crystalline resin that forms a lamellar crystal structure independently existing without contact with a release agent" means the lamellar crystal structure shown in FIG. This is the Feret diameter of the region (C) 5 surrounded by the broken line containing the crystalline resin to be formed.

Specifically, a cross section of the toner base particles produced in the same manner as above is photographed with a transmission electron microscope JEM-2000FX (manufactured by JEOL Ltd.) at an acceleration voltage of 80 kV at a magnification of 50,000, and a photographic image is scanned. Then, the horizontal ferret diameter (FERE H) of the region can be measured by using an image processing analyzer LUZEX AP (manufactured by Nireco Corporation).
Similarly, for the average major axis (major axis) of the region (B), the maximum major axis (MX LNG) is measured instead of the horizontal ferret diameter (FERE H) to determine the average major axis.
The average domain diameter (or average major axis and average minor axis) of these regions is measured as an arithmetic average value of 100 observed toner base particles.

  The average major axis of the region (B) is preferably in the range of 200 to 2000 nm, particularly preferably in the range of 500 to 1000 nm.

  Since the compatibility with the binder resin can be adjusted and the unevenness caused by crystal growth can be minimized even when stored in a high temperature and high humidity environment, images can be formed with stable image quality. It is more preferable because it can

  Further, the average domain diameter of the region (A) is preferably in the range of 200 to 2500 nm, and particularly preferably in the range of 800 to 1500 nm.

  When the average domain diameter of the area (A) is within the above range, the toner melts and the deformation proceeds, so that excellent low-temperature fixability is exhibited, and the exudation amount of the release agent is in the optimum range. The difference in the amount of the release agent between the part having the image and the part having no image is preferable, and the difference in gloss can be minimized, which is preferable.

Further, the average domain diameter of the region (C) is preferably within the range of 100 to 2000 nm, and particularly preferably within the range of 500 to 1500 nm.
This is because when the content is within the range, the toner is melted and the deformation proceeds, so that the toner exhibits excellent low-temperature fixability, and even when stored in a high-temperature and high-humidity environment, unevenness caused by crystal growth is minimized. Therefore, it is preferable in that an image can be formed with stable image quality.

[Cross-sectional area ratio]
The cross-sectional area ratio of the regions (A) to (C) was calculated as follows. The cross-sectional area of the region (A + B + C) containing the crystalline resin and the cross-sectional area of the region (D) independently containing the release agent, which does not contact the crystalline resin, are used as the image processing analysis device LUZEX AP ( It can be measured using "Area AREA" manufactured by Nireco Corporation. For the area, the area surrounded by the outer contour is measured. This cross-sectional area ratio is also calculated as an arithmetic mean value of 100 toner base particles in which all the regions (A) to (C) are observed.
Then, of the total of the region (A + B + C) containing the crystalline resin and the region (D) containing the release agent which independently exists without contacting the crystalline resin, the toner base of the region (A) is included. The ratio (A / (A + B + C + D)) of the particles in the cross-sectional area is preferably in the range of 0.35 to 0.90.
Within these numerical ranges, the releasing agent is appropriately exuded without being contaminated with the releasing agent and the areas (A) to (C) are formed, so that the glossiness of the image varies. It is preferable in that the above can be suppressed.

The ratio of the area (B) (B / (A + B + C + D)) is preferably in the range of 0.05 to 0.30.
When it is 0.05 or more, it is possible to suppress the glossiness variation due to the image cooling speed, and when it is 0.30 or less, CPES and APES at the time of fixing are appropriately compatible with each other. Can be suppressed.
Further, the ratio (C / (A + B + C + D)) of the region (C) is preferably 0.35 to 0.90. When it is 0.35 or more, the toner is sufficiently deformed at the time of heat melting, so that the low temperature fixing property can be secured. When it is 0.90 or less, crystal growth that occurs when the toner is stored in a high temperature and high humidity environment can be suppressed, and unevenness can be suppressed, so that stable image quality can be obtained.
The proportions of A, B and C are not particularly limited, but they do not become zero because coexistence is important.

[Morph of toner base particles]
In the toner according to the present invention, the toner base particles may have a so-called single layer structure, or may have a core-shell structure (a form in which a resin forming a shell portion on the surface of the core particles is aggregated and fused). ) May be included. A resin particle having a core-shell structure is a resin region (shell portion) having a relatively high glass transition temperature on the surface of a resin particle (core particle) having a relatively low glass transition temperature containing a colorant, a release agent, etc. ) Has.
The core-shell structure is not limited to a structure in which the shell part completely covers the core particles, and for example, the shell part does not completely cover the core particles and the core particles are exposed in places. Including those that exist.
The cross-sectional structure of the core-shell structure can be confirmed using a known means such as a transmission electron microscope (TEM) or a scanning probe microscope (SPM).

  The emulsion aggregation method is a dispersion of resin particles (hereinafter, also referred to as “resin particles”) produced by emulsification, and particles of a colorant (hereinafter, also referred to as “colorant particles”) as necessary. Is a method of producing toner base particles by controlling the shape by mixing with the dispersion liquid of (1), aggregating to a desired particle size, and then fusing resin particles together. Here, the resin particles may contain a release agent and, if necessary, a charge control agent and the like.

[Metal concentration in toner particles]
The metal concentration in the toner base particles according to the present invention is preferably in the range of 20 to 2000 mass ppm. This is because the metal ions derived from the metal element contained in the toner base particles are crosslinked by an ionic bond between the crystalline resin and the amorphous polyester resin, and the thread-like crystal structure of the crystalline resin becomes the toner base particles. It is speculated that it can be stably present inside. As a result, the effect of low-temperature fixability due to the inclusion of a crystalline resin that forms a thread-like crystal structure can be more effectively exhibited, and even if the fixing temperature is lowered, the effect of good fixing separability is achieved. Obtainable.
Further, when the metal concentration is higher than 20 mass ppm, the above-mentioned effect of improving the fixing separability can be obtained, and when the metal concentration is lower than 2000 mass ppm, the low temperature fixability can be achieved without increasing the amount of crosslinking due to ionic bonds. The effect of can be fully obtained.

Further, the above metal concentration is preferably a concentration of a metal derived from at least one metal element selected from aluminum (Al), magnesium (Mg) and iron (Fe).
Further, from the viewpoint of coloring, aluminum (Al) and magnesium (Mg) are more preferable. Further, these metal elements are preferably metal elements derived from the aggregating agent used in the production of toner.

  As the aggregating agent, for example, a water-soluble metal salt having a divalent or trivalent metal element can be used, and specific examples thereof include magnesium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate and the like. And a divalent metal salt of aluminum chloride, aluminum sulfate, ferric chloride, ferric sulfate, and the like. These metal salts may be used alone or in combination of two or more.

(Measuring method of metal concentration)
The amount of the metal element present in the toner particles is not particularly limited as long as it can be quantified in a minute amount, and can be determined by acid decomposition / inductively coupled plasma emission spectrometry. Below, an example of measurement is shown.

(1. Pretreatment)
100 mg of toner particles are decomposed by sulfuric acid and nitric acid in a closed microwave decomposing device “ETHOS1 manufactured by Milestone General Company”. If there are undecomposed substances, hydrochloric acid, hydrofluoric acid, hydrogen peroxide, etc. are used to elute the target component. The decomposition liquid is appropriately diluted with ultrapure water.

(2. Measurement)
The measurement is performed using a high frequency inductively coupled plasma optical emission spectrometer (ICP-OES, manufactured by Hitachi High-Tech Science Co., Ltd., SPS3520UV). The wavelength is not limited to the following as long as it has no interference and high sensitivity. For example, Al can be measured at 167.079 nm, Mg can be measured at 279.553 nm, and Fe can be measured at 259.940 nm. The calibration curve is prepared by adding a standard solution for atomic absorption of each element to a decomposition solution containing no sample and adjusting it so that it has the same acid concentration as the sample solution.

[Crystalline resin]
As the crystalline resin according to the present invention, a crystalline resin known in the art can be used, but it is preferable to include a crystalline polyester resin. This is because the crystalline polyester resin is easy to control the melting temperature and the crystal structure, and melts when the toner is heated to be compatible with the amorphous polyester resin to soften the amorphous polyester resin.
Here, the "crystalline polyester resin" refers to a known polyester resin obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polyvalent carboxylic acid) and a divalent or higher valent alcohol (polyhydric alcohol). In differential scanning calorimetry (DSC), a resin having a clear endothermic peak instead of a stepwise endothermic change.
The clear endothermic peak specifically means a peak in which the half width of the endothermic peak is within 15 ° C. when measured at a heating rate of 10 ° C./min in differential scanning calorimetry (DSC). To do.

  The polycarboxylic acid is a compound containing two or more carboxy groups in one molecule. Specifically, for example, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, n-dodecylsuccinic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid. Saturated aliphatic dicarboxylic acids such as; cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid; trivalent or higher polycarboxylic acids such as trimellitic acid and pyromellitic acid Acid; and anhydrides of these carboxylic acid compounds, alkyl esters having 1 to 3 carbon atoms, and the like. These may be used alone or in combination of two or more.

  Polyhydric alcohol is a compound containing two or more hydroxy groups in one molecule. Specifically, for example, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1 Aliphatic diols such as 1,8-octanediol, 1,9-nonanediol, dodecanediol, neopentyl glycol and 1,4-butenediol; trivalent or higher polyvalent compounds such as glycerin, pentaerythritol, trimethylolpropane and sorbitol Examples include alcohol. These may be used alone or in combination of two or more.

The melting point (Tm) of the crystalline polyester resin (hybrid crystalline polyester resin and non-hybrid crystalline polyester resin described later) is preferably in the range of 55 to 90 ° C, more preferably in the range of 75 to 85 ° C. Is.
When the melting point of the crystalline polyester resin is within the above range, sufficient low temperature fixability can be obtained. The melting point of the crystalline polyester resin can be controlled by the resin composition.

  In the present invention, the melting point of the crystalline polyester resin is a value measured as follows. That is, using a differential scanning calorimeter “Diamond DSC” (manufactured by Perkin Elmer Co., Ltd.), a first temperature raising process of raising the temperature from 0 ° C. to 200 ° C. at a temperature raising rate of 10 ° C./min, a cooling rate of 10 ° C./min to 200 ° C. Measured under the measurement conditions (heating / cooling conditions) that undergo a cooling process of cooling from 0 ° C to 0 ° C and a second heating process of heating from 0 ° C to 200 ° C at a heating rate of 10 ° C / min in this order. Based on the DSC curve obtained by this measurement, the melting point (Tm) is the endothermic peak top temperature derived from the crystalline polyester resin in the first temperature rising process. As a measurement procedure, 3.0 mg of a measurement sample (crystalline polyester resin) is enclosed in an aluminum pan and set in a diamond DSC sample holder. The reference uses an empty aluminum pan.

  The molecular weight of the crystalline polyester resin measured by gel permeation chromatography (GPC) is preferably 5,000 to 50,000 in terms of weight average molecular weight (Mw) and 1,500 to 25,000 in terms of number average molecular weight (Mn). The molecular weight of the crystalline polyester resin measured by GPC is measured in the same manner as above except that the crystalline polyester resin was used as a measurement sample.

  The mass ratio of the amorphous polyester resin and the crystalline resin (amorphous polyester resin / crystalline resin) is preferably 97/3 to 70/30, and more preferably 95/5 to 75/25. .. When the mass ratio (amorphous polyester resin / crystalline resin) is in the above range, the crystalline resin is not exposed on the surface of the toner particles to be formed, or even if exposed, the amount thereof is extremely small, In addition, a minimum amount of crystalline resin can be introduced into the toner particles in order to achieve low temperature fixability.

[Hybrid crystalline polyester resin and non-hybrid crystalline polyester resin]
The crystalline resin is a crystalline resin formed by chemically bonding a polyester polymerized segment and another polymerized segment (hereinafter, a crystalline resin having a plurality of such segments is also simply referred to as “hybrid crystalline resin”, It is preferable that the crystalline resin not having the plurality of segments is also simply referred to as “non-hybrid crystalline resin”.
At this time, it is preferable that the polyester polymerized segment and the other polymerized segment are a crystalline resin bonded via a bireactive monomer.

The polyester polymerized segment is preferably composed of a crystalline polyester resin. Since the crystalline resin contains the hybrid resin, the thickness of the lamellar crystal structure due to the folding of the molecular chains can be lengthened to some extent (that is, the crystallinity can be increased), and the lamellar crystal structure described above can be used. It becomes easy to control the aspect ratio and the thickness of the lamellar crystal structure within a predetermined range.
This is because the crystalline polyester polymerized segment introduced into the hybrid crystalline resin has a high affinity with the amorphous polyester resin, and thus the hybrid crystalline polyester resin and the amorphous polyester resin are easily compatible ( It is thought that the molecular chains of the crystalline resin are easily arranged as a result.

(Polyester polymerization segment)
As the polyester polymerized segment that constitutes the hybrid crystalline polyester resin, for example, an amorphous polyester polymerized segment is preferable. The amorphous polyester polymerized segment is composed of a resin obtained by polymerizing a polyester monomer.
Here, as the polyester monomer, those described below as the monomer constituting the polyester resin may be used in the same manner, and thus detailed description thereof will be omitted here.

There is no particular limitation on the content of the amorphous polyester polymerized segment other than the crystalline polyester resin in the hybrid crystalline polyester resin (hybridization rate (“HB rate” described in Examples described later; mass ratio)). However, the hybridization rate of the hybrid crystalline polyester resin is more preferably in the range of 5 to 30% by mass, further preferably in the range of 5 to 20% by mass, and 5 to 15% by mass. Within the range, it is particularly preferable.
When the value of the hybridization rate in the hybrid crystalline resin is within this range, there is an advantage that a lamellar crystal structure, which is a characteristic constitution of the electrostatic latent image developing toner of the present invention, is easily formed.

Compared to non-hybrid crystalline polyester resin, the hybrid crystalline polyester resin originally has gathered crystalline polymerized segment parts, so that the crystalline polymerized segment parts are easily arranged uniformly during crystallization, and the lamellar crystal structure is formed. Easy to appear. Among the hybrid crystalline resins, a particularly ordered crystal arrangement is likely to be formed, and a lamellar crystal structure is likely to be formed.
In the toner of the present invention in which the toner base particles have a region containing a thread-like crystal structure, a structure, a lamella-like crystal structure, etc., the crystalline resin is a combination of a hybrid crystalline polyester resin and a non-hybrid crystalline polyester resin. Preferably.

(Amorphous polyester polymerized segment)
The amorphous polyester polymerized segment that constitutes the hybrid crystalline resin (hereinafter, also simply referred to as “amorphous segment”) controls the affinity between the amorphous polyester resin that constitutes the binder resin and the hybrid resin. This is an essential segment for. The presence of the amorphous segment improves the affinity between the hybrid resin and the amorphous polyester resin, facilitates the incorporation of the hybrid resin into the amorphous polyester resin, and improves the charging uniformity. it can.
The amorphous segment is an amorphous segment obtained by a polycondensation reaction of a divalent or higher carboxylic acid (polyvalent carboxylic acid) as a monomer constituting the segment and a divalent or higher valent alcohol (polyhydric alcohol). It is a part derived from a hydrophilic polyester resin.
The fact that the hybrid resin used in the present invention has an amorphous segment together with the crystalline segment can be confirmed by specifying the chemical structure of the hybrid resin. At this time, the identification of the chemical structure can be confirmed by identifying the chemical structure using, for example, NMR measurement or methylation reaction P-GC / MS measurement.

Further, the amorphous segment has no melting point and has a relatively high glass transition temperature (Tg) when a differential scanning calorimetry (DSC) is performed on a resin having the same chemical structure and molecular weight as the segment. It is a polymerized segment. At this time, regarding the resin having the same chemical structure and molecular weight as the segment, the glass transition temperature (Tg) in the temperature rising process of DSC measurement is preferably 30 to 80 ° C., and particularly 40 to 64 ° C. preferable. The glass transition temperature (Tg) can be measured by the method described in the examples.
The amorphous segment is not particularly limited as long as it is as defined above, and in addition to the characteristics shown by the DSC measurement, if the resin has the characteristics derived from the above-mentioned crystalline segment, the resin is It corresponds to a hybrid resin having an amorphous segment and a crystalline segment.

  The amorphous segment is obtained by polycondensation reaction of a polyvalent carboxylic acid and a polyhydric alcohol as monomers constituting the segment, as described above. The monomer preferably contains at least one of the monomers constituting the amorphous polyester resin (amorphous polyester resin forming a continuous phase in the binder resin). With such a form, the affinity between the main chain portion of the amorphous segment and the amorphous polyester resin is improved. As a result, the affinity between the hybrid resin and the amorphous polyester resin that constitutes the binder resin together with the hybrid resin is further improved. Therefore, the hybrid resin is more easily incorporated into the amorphous polyester resin, and the charging uniformity is further improved.

  Furthermore, in terms of improving the affinity between the hybrid resin and the amorphous polyester resin, the polyvalent carboxylic acid that constitutes the amorphous segment contains at least one polyvalent carboxylic acid that constitutes the amorphous polyester resin. It is preferable that the polyhydric alcohol which is included and which constitutes the amorphous segment contains at least one of the polyhydric alcohol which constitutes the amorphous polyester resin. Furthermore, from the viewpoint of easily improving the affinity between the hybrid resin and the amorphous polyester resin, all the polyvalent carboxylic acids and polyhydric alcohols forming the amorphous segment are amorphous polyester resins. It is even more preferable that it is contained in the polyvalent carboxylic acid and the polyhydric alcohol constituting the.

The polyvalent carboxylic acid component and the polyhydric alcohol component constituting the amorphous segment each preferably have a valence of 2 or more. The upper limit of the valence is not particularly limited, but is substantially about 6. In particular, the polyvalent carboxylic acid component and the polyhydric alcohol component having a valence of 2 (that is, the dicarboxylic acid and the diol) mainly constitute the main chain of the amorphous segment. On the other hand, the polyvalent carboxylic acid component and the polyhydric alcohol component having a valence of 3 or more also serve as a starting point (crosslinking point) for grafting the crystalline segment as a side chain in addition to constituting the main chain. Fulfill Further, by including such a cross-linking component, it is possible to suppress the decrease in elastic modulus on the high temperature side and improve the offset property on the high temperature side.
Therefore, as a particularly preferable embodiment, the polyvalent carboxylic acid component and the polyhydric alcohol component have a valence of 2 (that is, a dicarboxylic acid component and a diol component) and a valence of 3 or more (a polyvalent valence of 3 or more). The carboxylic acid component and the trihydric or higher polyhydric alcohol component) will be described respectively.

(Dicarboxylic acid component)
As the dicarboxylic acid component, an unsaturated aliphatic dicarboxylic acid, an aromatic dicarboxylic acid or a derivative thereof is preferably used, and a saturated aliphatic polycarboxylic acid may be used in combination as long as an amorphous segment can be formed. ..
Examples of the unsaturated aliphatic dicarboxylic acid include methylene succinic acid, fumaric acid, maleic acid, 3-hexenedioic acid, 3-octenedioic acid, dodecenyl succinic acid, and lower alkyl esters thereof. An acid anhydride can also be used. Among these, fumaric acid is preferably used from the viewpoint of easy availability and easy emulsification.

Examples of the aromatic dicarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, t-butylisophthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-phenylenediacetic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, anthracene dicarboxylic acid and the like can be mentioned, and lower alkyl esters and acid anhydrides thereof can also be used. Among these, terephthalic acid, isophthalic acid, and t-butylisophthalic acid are preferably used from the viewpoints of easy availability and easy emulsification.
The number of carbon atoms of the dicarboxylic acid is not particularly limited, but in particular, the number of carbon atoms is preferably from 1 to 20, more preferably from 2 to 15 and more preferably from the viewpoint of easily optimizing thermal characteristics. It is especially preferable that it is 3-12. The dicarboxylic acid component is not limited to one type, and two or more types may be mixed and used.

(Trivalent or higher polycarboxylic acid component)
As the trivalent or higher polyvalent carboxylic acid component, it is preferable to use unsaturated aliphatic polyvalent carboxylic acid, aromatic polyvalent carboxylic acid and derivatives thereof, as long as an amorphous segment can be formed, saturated aliphatic polycarboxylic acid can be used. You may use together polyvalent carboxylic acid.
Examples of the unsaturated aliphatic carboxylic acid include 3-butene-1,2,3 tricarboxylic acid, 4-pentene-1,2,4 tricarboxylic acid, aconitic acid and other tricarboxylic acids; 4-pentene-1,2,3 , 4 tetracarboxylic acid and other tetracarboxylic acids, etc., and lower alkyl esters and acid anhydrides thereof can also be used.

Examples of the aromatic polycarboxylic acid include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid (trimesic acid), and 1,2,4-naphthalenetricarboxylic acid. And tricarboxylic acids such as hemimellitic acid; tetracarboxylic acids such as pyromellitic acid and 1,2,3,4-butanetetracarboxylic acid; hexacarboxylic acids such as mellitic acid; and lower alkyl esters thereof. An acid anhydride can also be used. Of these, trimellitic acid is preferably used from the viewpoint of easy availability and easy emulsification.
The number of carbon atoms of the polyvalent carboxylic acid having a valence of 3 or more is not particularly limited, but in particular, the number of carbon atoms is preferably 3 to 20 and the number of carbon atoms is 5 to 15 since thermal characteristics are easily optimized. More preferably, the carbon number is particularly preferably 6 to 12. The polycarboxylic acid component is not limited to one type, and two or more types may be mixed and used.

(Composition ratio of other components and polycarboxylic acid components)
Examples of the other aliphatic polycarboxylic acid that can be used together with the unsaturated aliphatic polycarboxylic acid (divalent or higher) and the aromatic polycarboxylic acid (divalent or higher) include, for example, the crystalline polyester polymerization described above. The saturated aliphatic dicarboxylic acid mentioned as an example of the segment (crystalline segment) and the like are preferable.
Content of unsaturated aromatic polyvalent carboxylic acid and aromatic polyvalent carboxylic acid in the polyvalent carboxylic acid component (dicarboxylic acid and polyvalent carboxylic acid having 3 or more valences) for forming an amorphous segment (a plurality of types In the case of containing) is preferably 50 constituent mol% or more, more preferably 70 constituent mol% or more, further preferably 80 constituent mol% or more, and particularly preferably 100 constituent mol%. .. As described above, when the content of the polyvalent carboxylic acid component is 50 mol% or more, the characteristics of the amorphous segment can be sufficiently ensured.

(Diol component)
As the diol component, unsaturated aliphatic diols, aromatic diols and derivatives thereof are preferably used from the viewpoint of chargeability and toner strength, and saturated aliphatic polyhydric alcohols can be used as long as they can form an amorphous segment. You may use together.
Examples of the unsaturated aliphatic diols include 2-butene-1,4-diol, 3-butene-1,4-diol, 2-butyne-1,4-diol, 3-butyne-1,4-diol. , 9-octadezene-7,12-diol and the like, and derivatives thereof can also be used. Among these, 2-butene-1,4-diol is preferably used from the viewpoint of easy availability and easy emulsification.

Examples of the aromatic diol include bisphenols such as bisphenol A and bisphenol F, and alkylene oxide adducts of bisphenols such as ethylene oxide adducts and propylene oxide adducts thereof, and derivatives thereof. Can also be used. Among these, it is preferable to use a bisphenol A-based compound such as an ethylene oxide adduct and a propylene oxide adduct of bisphenol A from the viewpoints of improving the charging uniformity of the toner and easily optimizing the thermal characteristics.
The diol component is not limited to one type, and two or more types may be mixed and used.

(Trihydric or higher polyhydric alcohol component)
As the trihydric or higher polyhydric alcohol component, unsaturated aliphatic polyhydric alcohols, aromatic polyhydric alcohols and derivatives thereof are preferably used, and saturated aliphatic polyhydric alcohols can be used as long as amorphous segments can be formed. You may use together.
Examples of the unsaturated aliphatic polyhydric alcohol include glycerin, trimethylolpropane, pentaerythritol, sorbitol and the like, and derivatives thereof can also be used.

Examples of the aromatic polyhydric alcohol include 1,3,5-benzenetriol, 1,2,4-benzenetriol, 1,3,5-trihydroxymethylbenzene and the like. It can also be used.
The number of carbon atoms of the polyhydric alcohol having 3 or more valences is not particularly limited, but it is particularly preferable that the number of carbon atoms is 3 to 20 because thermal characteristics are easily optimized. The polyhydric alcohol component is not limited to one type, and two or more types may be mixed and used.

(Composition ratio of other components and polyhydric alcohol components)
Examples of other aliphatic polyhydric alcohols that can be used together with the unsaturated aliphatic polyhydric alcohol (dihydric or higher) and the aromatic polyhydric alcohol (dihydric or higher) include, for example, the crystalline polyester polymer segment (crystal). The same as the saturated aliphatic diol mentioned as an example of the sex segment) is preferably used.
In the polyhydric alcohol component (diol and polyhydric alcohol having a valence of 3 or more) for forming the amorphous segment, the content of the unsaturated aliphatic polyhydric alcohol and the aromatic polyhydric alcohol (in the case of containing plural kinds, The total) is preferably 50 constituent mol% or more, more preferably 70 constituent mol% or more, further preferably 80 constituent mol% or more, and particularly preferably 100 constituent mol%. When the content of the polyhydric alcohol component is 50% by mole or more, the characteristics of the amorphous segment can be sufficiently ensured.

The method for forming the amorphous segment is not particularly limited, and it is possible to form the segment by polycondensing (esterifying) the polyvalent carboxylic acid and the polyhydric alcohol using a known esterification catalyst. it can. The details of the method of manufacturing the amorphous segment are the same as the method of manufacturing the crystalline segment described above, and thus detailed description thereof is omitted.
The content of the amorphous segment in the hybrid crystalline resin (hybridization rate (“HB rate” described in Examples described later)) is not particularly limited, but the hybrid crystalline resin may be a non-hybrid crystalline resin. When used in combination with, the hybridization rate of the hybrid crystalline resin is more preferably in the range of 5 to 30% by mass, further preferably in the range of 5 to 20% by mass. It is particularly preferable that it is within the range. Further, when the hybrid crystalline resin is not used together with the non-hybrid crystalline resin, the hybridizing rate of the hybrid crystalline resin is preferably 40% by mass or more, more preferably 40 to 60% by mass, and 45 It is more preferable that the content is ˜50% by mass.

  When the value of the hybridization rate in the hybrid crystalline resin is within this range, there is an advantage that the lamella-like crystal structure and the thread-like crystal structure, which are the characteristic constitutions of the toner according to the present invention, are easily present together. Compared to non-hybrid crystalline resin, the hybrid crystalline resin originally has gathered crystalline segment portions, so that the crystalline segment portions are easily arranged uniformly during crystallization, and a lamellar crystal structure is likely to appear. Among the hybrid crystalline resins, it is particularly easy to form a neat crystal arrangement and easily take a lamellar crystal structure. On the other hand, in the non-hybrid crystalline resin, the crystalline segment portions are less concentrated than in the hybrid crystalline resin, and thus each of them forms a crystalline structure during crystallization. For this reason, it does not easily form a layered structure, and tends to appear as a single crystal structure like a filamentous substance.

[Method for producing hybrid crystalline resin]
As a method for producing the hybrid crystalline resin, an existing general scheme can be used. The following three are typical methods.
The method for producing a hybrid resin contained in the binder resin according to the present invention, the crystalline polyester polymerized segment (crystalline segment) as a side chain, the amorphous polyester polymerized segment (amorphous segment) as a main chain molecule The method is not particularly limited as long as it is a method capable of forming a polymer having a bonded structure. A preferred method for producing the hybrid resin used in the toner of the present invention will be described below.

It is preferable that the hybrid resin is produced by a method in which a resin that becomes a crystalline segment and a resin that becomes an amorphous segment are respectively prepared, and these are combined to produce a hybrid resin.
In this method, first, a polycarboxylic acid and a polyhydric alcohol are subjected to a condensation reaction to prepare a resin (crystalline polyester resin) to be a crystalline segment. In addition to the reaction system for preparing the crystalline polyester resin, the polyvalent carboxylic acid and the polyhydric alcohol constituting the resin (amorphous polyester resin) to be the amorphous segment are subjected to a condensation reaction to form the amorphous polyester resin. Prepare a polyester resin. Since the monomers used for preparing the crystalline polyester resin and the amorphous polyester resin are as described above, detailed description thereof will be omitted here.

  During the preparation of the amorphous polyester resin, the crystalline segment (side chain) is polymerized into the amorphous segment (main chain), so that the crystalline segment and the amorphous segment can react with each other (crosslinking point) Is preferably incorporated. The crosslinking point is incorporated by using a compound having a site capable of reacting with a carboxy group [-COOH] or a hydroxy group [-OH] remaining in the crystalline polyester resin during the production of the amorphous polyester resin. You can In order to incorporate such a site, it is preferable to use a trivalent or higher polyvalent carboxylic acid and / or a trivalent or higher polyhydric alcohol during the preparation of the amorphous polyester resin. The compounds that can be used as the polyvalent carboxylic acid and the polyhydric alcohol are as described above, and detailed description thereof will be omitted.

  Here, as the catalyst for synthesizing the polyester polymerized segment, various conventionally known catalysts can be used. Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, titanium compounds such as titanium diisopropylate bistriethanolaminate, and the like. Acid etc. are mentioned.

[Amorphous polyester resin]
The amorphous polyester resin according to the present invention is characterized in that it is the main component of the binder resin contained in the toner base particles. Here, the "main component" means that the component constituting the binder resin accounts for 51% by mass or more.
Amorphous polyester resins usually do not have a melting point and have a relatively high glass transition temperature (Tg). More specifically, the glass transition temperature (Tg) is preferably in the range of 30 to 80 ° C, and particularly preferably in the range of 40 to 64 ° C. The glass transition temperature (Tg) is measured by the method described in the examples.
As the monomer constituting the amorphous polyester resin forming the continuous phase in the binder resin, the monomer described in the section of the amorphous polyester polymerized segment (amorphous segment) can be used.
Here, at least one of the monomers forming the amorphous polyester resin is preferably the same as the monomer forming the amorphous segment. With such a configuration, the affinity between the amorphous polyester resin and the hybrid resin is improved, and the hybrid resin is easily incorporated into the amorphous polyester resin. As a result, the charging uniformity is improved.

In addition, regarding the monomer forming the amorphous segment and the monomer forming the amorphous polyester resin, a more preferable form is described in the section of the amorphous polyester polymerized segment (amorphous segment). It is as follows.
From the viewpoint of improving the affinity between the amorphous polyester resin and the hybrid resin, and further improving the charging uniformity, all of the monomers constituting the hybrid resin are the monomers constituting the amorphous polyester resin. Is preferred.
As the polyhydric alcohol component and the polycarboxylic acid component as monomers forming the amorphous polyester resin, those listed as the above-mentioned amorphous polyester polymerized segment (amorphous segment) can be similarly used.

Among the above monomers, from the viewpoint of chargeability and toner strength, it is preferable that the polyhydric alcohol component is an aromatic diol or a derivative thereof. For example, bisphenols such as bisphenol A and bisphenol F, and their derivatives. It is preferable to use alkylene oxide adducts of bisphenols such as ethylene oxide adducts and propylene oxide adducts.
Among these, it is preferable to use ethylene oxide adducts and propylene oxide adducts of bisphenol A as the polyhydric alcohol component from the viewpoints of improving the charging uniformity of the toner and easily optimizing the thermal characteristics. These polyhydric alcohol components may be used alone or in combination of two or more.

Examples of the polyvalent carboxylic acid component to be condensed with the polyhydric alcohol component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalene dicarboxylic acid; Saturated aliphatic dicarboxylic acids; and lower alkyl esters of these acids, acid anhydrides and the like.
Among these, terephthalic acid, isophthalic acid, fumaric acid, and dodecenylsuccinic acid are preferably used as the polyvalent carboxylic acid component from the viewpoint of improving the charging uniformity of the toner. These polyvalent carboxylic acids may be used alone or in combination of two or more.
The method for preparing the amorphous polyester resin is not particularly limited, and the amorphous polyester resin can be produced by the same method as the method for producing the crystalline segment described in the section of the crystalline polyester polymerized segment (crystalline segment).
The amorphous polyester resin preferably has a weight average molecular weight (Mw) of 5,000 to 150,000, more preferably 10,000 to 70,000, from the viewpoint of easy control of plasticity.

[Release agent]
In the toner according to the present invention, when the toner base particles are configured to contain a release agent, the release agent is composed of a matrix phase (amorphous polyester resin phase) and a domain phase (crystalline resin phase). Although it may be contained in any of the above, it is particularly preferable that it is contained in the matrix phase (amorphous polyester resin phase) from the viewpoint of the surface exudation of the release agent during fixing.
As the wax, particularly low-molecular-weight polypropylene, polyethylene, or polyolefin wax such as oxidized polypropylene or polyethylene, and ester wax such as behenyl behenate can be preferably used.

When monoester waxes are used as a release agent, it tends to easily form a thread-like crystal structure that is not in contact with the release agent according to the present invention.
On the other hand, when a hydrocarbon wax having a small number of carbon chain branches and a small molecular weight distribution is used as the release agent, the structure according to the present invention tends to be easily formed. The reason for this is not clear, but due to the affinity balance with the crystalline resin and the surrounding resin, to form a thread-like crystal structure not in contact with the release agent according to the present invention, or the structure according to the present invention. It is supposed to form.
Therefore, in order to coexist the thread-like crystal structure, the structure, and the lamella-like crystal structure, it is preferable to use two kinds of release agents of different kinds in combination. For example, by using a hydrocarbon wax having a small number of carbon chain branches and a small molecular weight distribution in combination with a monoester wax having one ester bond, a thread-like crystal structure, a structure, and a lamellar crystal structure coexist. There is a tendency to make it easier.

  Further, even when the release agent is used alone, the filamentous crystal structure, the structure, and the lamellar crystal structure can coexist by balancing the affinity with the crystalline resin and the surrounding resin. it is conceivable that. Specifically, for example, a hydrocarbon wax having a large number of carbon chain branches and a relatively large molecular weight distribution, a polyvalent ester wax having a plurality of ester bonds, and having two or more kinds of functional groups by modification are functionally separated. The use of the release agent having a structure also facilitates the coexistence of the thread-like crystal structure, the structure, and the lamellar crystal structure. That is, as described above, the crystalline resin having a thread-like crystal structure which is not in contact with the release agent, the crystalline resin and the release agent are in contact with each other in the cross section of the toner base particles And a crystalline resin having a lamellar crystal structure that is not in contact with the mold releasing agent are present. ”As one of the methods for realizing the configuration. There is a method.

Specifically, for example, polyolefin wax such as polyethylene wax and polypropylene wax; branched hydrocarbon wax such as microcrystalline wax; long-chain hydrocarbon wax such as paraffin wax and sazol wax; dialkyl such as distearyl ketone Ketone wax; carnauba wax, montan wax, behenyl behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanedioldi Ester waxes such as stearate, tristearyl trimellitate and distearyl maleate; ethylenediamine behenylamide, trimellitic acid tristearylamide, etc. Such as amide waxes.
Among these, from the viewpoint of releasability at the time of low temperature fixing, it is preferable to use one having a low melting point, specifically one having a melting point of 40 to 90 ° C. The content of the release agent in the toner base particles is preferably 1 to 20% by mass, more preferably 5 to 20% by mass.

[Charge control agent]
The toner base particles according to the present invention may contain a charge control agent. Examples of the charge control agent include metal complexes of salicylic acid derivatives with zinc or aluminum (salicylic acid metal complexes), calixarene compounds, organic boron compounds, and fluorine-containing quaternary ammonium salt compounds.
The content ratio of the charge control agent is preferably in the range of usually 0.1 to 10 parts by mass, and preferably in the range of 0.5 to 5 parts by mass with respect to 100 parts by mass of the binder resin in the toner. Is more preferable.

[External additive]
The toner base particles according to the present invention can be used as the toner particles as they are, but from the viewpoint of improving charging performance, fluidity, or cleaning property of the toner, known inorganic fine particles or organic fine particles are used on the surface thereof. It is preferable to add particles such as the above and a lubricant as an external additive.
Various external additives may be used in combination. The particles include, for example, silica fine particles, inorganic fine particles such as alumina fine particles and titania fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, or strontium titanate fine particles and zinc titanate fine particles. Inorganic titanate compound fine particles and the like. Examples of lubricants include zinc stearate, aluminum, copper, magnesium, calcium and the like salts, oleic acid zinc, manganese, iron, copper, magnesium and the like salts, palmitic acid zinc, copper, magnesium, calcium and the like. Examples thereof include salts, salts of zinc and calcium of linoleic acid, and metal salts of higher fatty acids such as salts of zinc and calcium of ricinoleic acid. These external additives may be surface-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, or the like, from the viewpoint of heat resistant storage stability and environmental stability.
The addition amount of these external additives is preferably in the range of 0.05 to 5 parts by mass with respect to 100 parts by mass of the toner base particles.

[Toner manufacturing method]
Examples of the method for producing the toner of the present invention include a pulverization method, a mini-emulsion method, an emulsion aggregation method, and other known methods. However, as a manufacturing method for realizing the above-described structure in which the three regions (A) to (C) characteristic of the present invention are present, the particle size and shape of the toner base particles are controlled. The production method preferably includes a step of cooling later.

By performing this cooling step, it is possible to prevent the agglomeration of the crystallizing substance (for example, the crystalline resin or the release agent), and thus it is easy to create a coexisting state of the thread-like crystal structure, the structure, and the lamella-like crystal structure. I'm guessing that. In addition, it is preferable to perform rapid cooling in the cooling step.
The rapid cooling depends on the temperature before cooling and the target temperature after cooling, but as a guide, the cooling rate is 8 ° C./min or more. By performing this cooling step (preferably rapid cooling) after controlling the particle size and shape of the toner base particles, the crystallinity of the thread-like crystal structure that does not contact the release agent and exists independently Resin, structure in which the crystalline resin is in contact with the release agent, and easier to maintain the coexistence state of the crystalline resin having a lamellar crystal structure that does not contact the release agent and exists independently Become. Further, the emulsion aggregation method is more preferable from the viewpoint of production cost and production stability because it is possible to easily reduce the particle size of the toner base particles. Therefore, when the emulsion aggregation method is used, it is more preferable to perform the shape control by aggregating until a desired particle size is obtained and further performing fusion bonding between the resin particles, followed by cooling (preferably rapid cooling).

  The emulsion aggregation method is a dispersion of resin particles (hereinafter, also referred to as “resin particles”) produced by emulsification, and dispersion of colorant particles (hereinafter, also referred to as “colorant particles”) as necessary. This is a method of producing toner base particles by controlling the shape by mixing with a liquid, aggregating to a desired particle size, and fusing resin particles together. Here, the resin particles may contain a release agent and, if necessary, a charge control agent and the like.

[Image forming method]
An image forming method in which the electrostatic latent image developing toner of the present invention can be preferably used will be described using the image forming apparatus shown in FIG.
The image forming apparatus 100 illustrated in FIG. 2 includes an image reading unit 110, an image processing unit 30, an image forming unit 40, a sheet conveying unit 50, and a fixing device 60.

  The image forming unit 40 includes image forming units 41Y, 41M, 41C, and 41K that form images with toners of Y (yellow), M (magenta), C (cyan), and K (black). Since these have the same configuration except for the toner to be stored, the symbols representing the colors may be omitted hereinafter. The image forming section 40 further includes an intermediate transfer unit 42 and a secondary transfer unit 43. These correspond to a transfer device.

The image forming unit 41 includes an exposure device 411, a developing device 412, a photosensitive drum 413, a charging device 414, and a drum cleaning device 415.
The photoconductor drum 413 is, for example, a negative charging type organic photoconductor. The surface of the photoconductor drum 413 has photoconductivity. The photoconductor drum 413 corresponds to a photoconductor. The charging device 414 is, for example, a corona charger. The charging device 414 may be a contact charging device that charges a contact charging member such as a charging roller, a charging brush, or a charging blade by contacting the photosensitive drum 413. The exposure device 411 includes, for example, a semiconductor laser as a light source, and a light deflection device (polygon motor) that irradiates the photosensitive drum 413 with laser light according to an image to be formed.

  The developing device 412 is a two-component developing type developing device. The developing device 412 includes, for example, a developing container that stores a two-component developer, a developing roller (magnetic roller) that is rotatably disposed in an opening of the developing container, and a developing container that allows the two-component developer to communicate with each other. A partition wall for partitioning the inside, a transport roller for transporting the two-component developer on the opening side of the developing container toward the developing roller, and a stirring roller for stirring the two-component developer in the developing container. .. The developing container contains the toner as a two-component developer.

  The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422 that presses the intermediate transfer belt 421 against the photosensitive drum 413, a plurality of support rollers 423 including a backup roller 423A, and a belt cleaning device 426. The intermediate transfer belt 421 is looped around a plurality of support rollers 423. By rotating at least one drive roller of the plurality of support rollers 423, the intermediate transfer belt 421 travels in the direction of arrow A at a constant speed.

  The secondary transfer unit 43 has an endless secondary transfer belt 432 and a plurality of support rollers 431 including a secondary transfer roller 431A. The secondary transfer belt 432 is stretched in a loop shape by the secondary transfer roller 431A and the support roller 431.

  The fixing device 60 fixes, for example, a fixing roller 62, an endless heating belt 63 that covers the outer peripheral surface of the fixing roller 62, heats and melts the toner that forms the toner image on the paper S, and the paper S. And a pressure roller 64 that presses against the roller 62 and the heat generation belt 63.

  The image forming apparatus 100 further includes an image reading unit 110, an image processing unit 30, and a sheet conveying unit 50. The image reading unit 110 includes a paper feeding device 111 and a scanner 112. The paper transport unit 50 has a paper feed unit 51, a paper discharge unit 52, and a transport path unit 53. The paper S (standard paper, special paper) identified based on the basis weight, size, etc. is accommodated in each of preset types in the three paper feed tray units 51a to 51c constituting the paper feed unit 51. .. The transport path portion 53 has a plurality of transport roller pairs such as a registration roller pair 53a.

An example of the image forming method by the image forming apparatus 100 will be described.
The scanner 112 optically scans and reads the document D on the contact glass. The reflected light from the document D is read by the CCD sensor 112a and becomes input image data. The input image data is subjected to predetermined image processing in the image processing unit 30 and sent to the exposure device 411.

  The photoconductor drum 413 rotates at a constant peripheral speed. The charging device 414 uniformly charges the surface of the photoconductor drum 413 to have a negative polarity. In the exposure device 411, the polygon mirror of the polygon motor rotates at high speed, the laser light corresponding to the input image data of each color component develops along the axial direction of the photoconductor drum 413, and the photoconductor runs along the axial direction. The outer peripheral surface of the drum 413 is irradiated. In this way, an electrostatic latent image is formed on the surface of the photoconductor drum 413.

  In the developing device 412, the toner particles are charged by stirring and carrying the two-component developer in the developing container, the two-component developer is carried to the developing roller, and a magnetic brush is formed on the surface of the developing roller. The charged toner particles electrostatically adhere to the portion of the electrostatic latent image on the photoconductor drum 413 from the magnetic brush. In this way, the electrostatic latent image on the surface of the photoconductor drum 413 is visualized, and a toner image corresponding to the electrostatic latent image is formed on the surface of the photoconductor drum 413.

  The toner image on the surface of the photoconductor drum 413 is transferred to the intermediate transfer belt 421 by the intermediate transfer unit 42. The transfer residual toner remaining on the surface of the photoconductor drum 413 after the transfer is removed by a drum cleaning device 415 having a drum cleaning blade in sliding contact with the surface of the photoconductor drum 413.

  When the intermediate transfer belt 421 is pressed against the photosensitive drum 413 by the primary transfer roller 422, the photosensitive drum 413 and the intermediate transfer belt 421 form a primary transfer nip for each photosensitive drum. At the primary transfer nip, the toner images of the respective colors are sequentially superimposed and transferred onto the intermediate transfer belt 421.

  On the other hand, the secondary transfer roller 431A is pressed against the backup roller 423A via the intermediate transfer belt 421 and the secondary transfer belt 432. As a result, a secondary transfer nip is formed by the intermediate transfer belt 421 and the secondary transfer belt 432. The sheet S passes through the secondary transfer nip. The sheet S is transported to the secondary transfer nip by the sheet transport unit 50. The correction of the inclination of the sheet S and the adjustment of the conveyance timing are performed by the registration roller unit provided with the registration roller pair 53a.

  When the sheet S is conveyed to the secondary transfer nip, the transfer bias is applied to the secondary transfer roller 431A. By applying the transfer bias, the toner image carried on the intermediate transfer belt 421 is transferred to the sheet S. The sheet S to which the toner image is transferred is conveyed toward the fixing device 60 by the secondary transfer belt 432.

  The fixing device 60 forms a fixing nip by the heating belt 63 and the pressure roller 64, and heats and presses the conveyed sheet S at the fixing nip portion. The toner particles forming the toner image on the paper S are heated and the crystalline resin is quickly melted inside the toner particles. As a result, the entire toner particles are quickly melted with a relatively small amount of heat, and the toner components are transferred to the paper S. Adhere to. In this way, the toner image is quickly fixed on the paper S with a relatively small amount of heat. The sheet S on which the toner image is fixed is ejected to the outside of the machine by the sheet ejection unit 52 having a sheet ejection roller 52a. In this way, a high quality image is formed.

  The transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer is removed by a belt cleaning device 426 having a belt cleaning blade that is in sliding contact with the surface of the intermediate transfer belt 421.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, “parts” or “%” is used, but unless otherwise specified, “parts by mass” or “% by mass” is indicated.

(Synthesis Example 1: Synthesis of crystalline polyester resin (cn-1))
The following raw material monomers for the crystalline polyester resin (CPES) unit were placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and heated to 170 ° C. to be dissolved. Then, Ti (OBu) ₄ (0.003 mass% with respect to the total amount of polyvalent carboxylic acid monomer) as an esterification catalyst was added, and while maintaining 170 ° C., water generated was distilled off for 5 hours. The reaction was carried out.
Adipic acid 330 parts by mass Ethylene glycol 45 parts by mass 1,4-butanediol 135 parts by mass

  Then, after reacting for 60 minutes, unreacted monomers were removed under reduced pressure (8 kPa). The amount of the monomer removed at this time was very small with respect to the raw material monomer ratio of the above resin.

(Synthesis Examples 2-3: Synthesis of crystalline polyester resins (cn-2) to (cn-3))
Crystalline polyester resins (cn-2) to (cn-3) were obtained in the same manner as in Synthesis Example 1 except that the addition amount of the raw material monomer of the crystalline polyester resin was changed.

(Synthesis Example 4: Synthesis of hybrid crystalline polyester resin (cm-1))
-Preparation of amorphous polyester polymerized segment (APES) In a reaction vessel equipped with a stirrer, a nitrogen inlet tube, a temperature sensor and a rectification column, the following raw material monomer (polyvalent carvone) of the amorphous polyester polymerized segment (APES) was prepared. Acid monomer and polyhydric alcohol monomer) were added and the temperature was raised to 190 ° C. over 1 hour, and it was confirmed that the reaction system was uniformly stirred. After that, Ti (OBu) ₄ (0.003 mass% with respect to the total amount of the polyvalent carboxylic acid monomer) as an esterification catalyst was added, and while maintaining the temperature at 190 ° C., the generated water was distilled off for 5 hours. The reaction was carried out.

<Polyvalent carboxylic acid monomer>
Terephthalic acid (TPA) 3.3 parts by weight Fumaric acid (FA) 0.3 parts by weight Trimellitic acid (TMA) 0.6 parts by weight

<Polyhydric alcohol monomer>
2,2-bis (4-hydroxyphenyl) propane ethylene oxide 2 mol adduct (BPA-EO) 2.1 parts by mass 2,2-bis (4-hydroxyphenyl) propane propylene oxide 2 mol adduct (BPA-PO) ) 6.9 parts by mass

-Preparation of crystalline polyester resin (CPES) The following raw material monomers for the crystalline polyester resin (CPES) segment were placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple and heated to 170 ° C. It was heated and dissolved. Then, Ti (OBu) ₄ (0.003 mass% with respect to the total amount of polyvalent carboxylic acid monomer) as an esterification catalyst was added, and while maintaining 170 ° C., water generated was distilled off for 5 hours. The reaction was carried out.
Adipic acid 330 parts by mass Ethylene glycol 45 parts by mass 1,4-butanediol 135 parts by mass Then, after reacting for 60 minutes, unreacted monomers were removed under reduced pressure (8 kPa). The amount of the monomer removed at this time was very small with respect to the raw material monomer ratio of the above resin.

-Preparation of hybrid resin 0.8 mass part of Ti (OBu) ₄ as an esterification catalyst and the amorphous polyester resin prepared by the above procedure were put into the reaction vessel in which the CPES was prepared, and the temperature was raised to 235 ° C. The reaction was carried out at a temperature and normal pressure (101.3 kPa) for 5 hours, and further under reduced pressure (8 kPa) for 1 hour.
Next, after cooling to 200 ° C., a hybrid crystalline polyester resin (cm-1) was obtained by reacting under reduced pressure (20 kPa) for 1 hour.

(Synthesis Examples 5 to 6: Synthesis of hybrid crystalline polyester resins (cm-2) to (cm-3))
Hybrid crystallinity was the same as in Synthesis Example 4 except that the amounts of the raw material monomers added to the crystalline polyester polymerized segment (CPES segment) and the amorphous polyester polymerized segment (APES segment) in the hybrid crystalline polyester were changed. Polyester resins (cm-2) to (cm-3) were obtained.

(Synthesis Example 7: Synthesis of amorphous polyester resin (x1))
Charge the following polyvalent carboxylic acid monomer and polyhydric alcohol components into a reaction vessel equipped with a stirrer, nitrogen introduction tube, temperature sensor and rectification column, and raise the temperature to 190 ° C in 1 hour, Was confirmed to be uniformly stirred. Then, the catalyst Ti (OBu) ₄ (0.003 mass% with respect to the total amount of the polyvalent carboxylic acid monomer) was added.
Further, while distilling off the produced water, the temperature was raised from 190 ° C. to 240 ° C. over 6 hours, and the dehydration condensation reaction was continued at 240 ° C. for an additional 6 hours to carry out polymerization to obtain an amorphous polyester resin (x1). Got

<Polyvalent carboxylic acid monomer>
Terephthalic acid (TPA) 30 parts by weight Fumaric acid (FA) 2.1 parts by weight Dodecenylsuccinic acid (DDSA) 9.6 parts by weight Trimellitic acid (TMA) 5.2 parts by weight

<Polyhydric alcohol monomer>
2,2-bis (4-hydroxyphenyl) propane ethylene oxide 2 mol adduct (BPA-EO) 24 parts by mass 2,2-bis (4-hydroxyphenyl) propane propylene oxide 2 mol adduct (BPA-PO) 76 Mass part

<Production Example 1: Preparation of release agent particle dispersion liquid (W-1)>
The following components were mixed, and a paraffin wax as a mold release agent was dissolved at an internal liquid temperature of 120 ° C. with a pressure discharge type homogenizer (Gorin homogenizer manufactured by Gorin Co., Ltd.). Then, a dispersion pressure of 5 MPa was applied for 120 minutes, followed by a dispersion treatment of 40 MPa for 360 minutes, followed by cooling to obtain a release agent particle dispersion (W-1). The volume average particle diameter D50v of the particles in the release agent particle dispersion liquid (W-1) was 225 nm. Then, ion-exchanged water was added to adjust the solid content concentration to 20.0% by mass.
Hydrocarbon wax (paraffin wax, n-paraffin ratio 90%, molecular weight distribution 26, melting point: 75 ° C.): 270 parts by mass Anionic surfactant (Daiichi Kogyo Seiyaku Co., Neogen RK, active ingredient amount: 60% by mass) ): 13.5 parts by mass (3.0% by mass with respect to the release agent as an active ingredient)
Ion-exchanged water: 21.6 parts by mass

<Production Example 2: Preparation of release agent particle dispersion liquid (W-2)>
A release agent particle dispersion liquid (W-2) was obtained in the same manner as in Production Example 1 except that the type of release agent was changed.
Ester wax (manufactured by NOF CORPORATION, trade name: Nissan Electol (registered trademark) WEP-3, melting temperature Tw = 73 ° C.): 270 parts by mass Anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Neogen RK, effective) Ingredient amount: 60% by mass): 13.5 parts by mass (3.0% by mass relative to the release agent as an active ingredient)
Ion-exchanged water: 21.6 parts by mass

<Preparation of Crystalline Resin (Crystalline Polyester Resin) Particle Dispersion Liquid (CA-1)>
The crystalline polyester resin (cn-1) was melted in an amount of 300 parts by mass and transferred in a molten state at a transfer speed of 100 parts by mass per minute to an emulsification disperser "Cavitron CD1010" (manufactured by Eurotech Co., Ltd.).
Simultaneously with the transfer of the crystalline polyester resin (cn-1) in the molten state, a dilute ammonia solution of a reagent was diluted with ion-exchanged water in an aqueous solvent tank to the emulsification disperser to give a diluted solution having a concentration of 0.37% by mass. Ammonia water was transferred at a transfer rate of 0.1 liter / min while heating to 100 ° C. with a heat exchanger.
Then, the emulsifying disperser was operated under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² to prepare a crystalline resin particle dispersion liquid (CA-1). The diluted ammonia water was added so that the degree of neutralization was 45%. The dispersion diameter of the crystalline resin particles in the crystalline resin particle dispersion liquid (CA-1) was 210 nm in terms of volume-based median diameter.

<Preparation of Crystalline Resin Particle Dispersions (CA-2) to (CA-5) and (CB-1) to (CB-5)>
The crystalline resin particle dispersion liquid (CA-2) was prepared in the same manner as in the preparation of the crystalline resin particle dispersion liquid (CA-1) except that the type and the degree of neutralization of the crystalline resin were changed as shown in Table 3. )-(CA-5) and (CB-1)-(CB-5) were prepared.
The degree of neutralization was obtained by converting the amount of ammonia used for neutralization into the amount of KOH used for neutralization and then using the value calculated by the following formula (1) as the degree of neutralization (unit:%). ..
Formula (1): Neutralization degree (%) = [(KOH amount [g] used for neutralization) / (KOH amount [g] capable of 100% neutralizing the terminal of the crystalline resin (crystalline polyester))] × 100

The volume-based median diameter (D50) as the dispersion diameter of the resin fine particles in the crystalline resin dispersion was measured by a dynamic light scattering method using a known "Microtrac UPA-150 (manufactured by Nikkiso Co., Ltd.)". I asked.
Specifically, the procedure was as follows. First, a few drops of measurement resin fine particles are dropped into a 50 mL graduated cylinder, 25 mL of pure water is added, and dispersed for 3 minutes using an ultrasonic cleaner "US-1 (manufactured by asone)" to prepare a measurement sample. did. Then, 3 mL of the measurement sample was placed in the cell of "Microtrac UPA-150", and it was confirmed that the value of Sample Loading was in the range of 0.1 to 100. And it measured on the following measurement conditions.

(Measurement condition)
Transparency: Yes
Refractive Index: 1.59
Particle Density: 1.05 g / cm ^3.
Spherical Particles: Yes
(Solvent conditions)
Refractive Index: 1.33
Viscosity: High (temp) 0.797 × 10 ⁻³ Pa · s / Low (temp) 1.002 × 10 ⁻³ Pa · s
The coefficient of variation in the volume-based particle size distribution of the resin particles is calculated by the following formula.
Coefficient of variation (CV value) (%) = (S2 / Dn) × 100
(In the formula, S2 represents the standard deviation in the volume-based particle size distribution, and Dn represents the volume-based average diameter MV.)

<Preparation of Aqueous Dispersion of Amorphous Polyester Resin Particles (PA-1)>
While maintaining a jacketed 3 liter reaction tank (BJ-30N manufactured by Tokyo Rika Kikai Co., Ltd.) equipped with a condenser, a thermometer, a water dropping device, and an anchor blade at 40 ° C. in a water circulation type constant temperature tank, A mixed solvent of 160 parts by mass of ethyl acetate and 100 parts by mass of isopropyl alcohol was added, 300 parts by mass of the amorphous polyester resin (x1) obtained in Synthesis Example 7 was added thereto, and 150 rpm was applied using a three-one motor. The resulting mixture was stirred and dissolved to obtain an oil phase. To this stirred oil phase, 10 mass% aqueous ammonia solution was dropped 14 parts by mass for 5 minutes, mixed for 10 minutes, and then 900 parts by mass of ion-exchanged water was dripped at a rate of 7 parts by minute per minute. And phase inversion was performed to obtain an emulsion.

800 parts by mass of the obtained emulsion and 700 parts by mass of ion-exchanged water were immediately put in a 2 liter eggplant flask and set in an evaporator (manufactured by Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. did.
While rotating the eggplant flask, the mixture was heated in a hot water bath at 60 ° C., and while paying attention to bumping, the pressure was reduced to 7 kPa to remove the solvent.

When the solvent recovery amount reached 1100 parts by mass, the pressure was returned to normal pressure, and the eggplant flask was water-cooled to obtain a dispersion liquid. There was no solvent odor in the obtained dispersion. The volume average particle diameter D50v of the resin particles in this dispersion was 130 nm. Thereafter, ion-exchanged water was added to adjust the solid content concentration to 20 mass%, which was used as an aqueous dispersion of amorphous polyester resin fine particles (PA-1).
Regarding the obtained aqueous dispersion of amorphous polyester resin particles (PA-1), the volume-based median diameter of the amorphous polyester resin particles is 220 nm, the glass transition temperature (Tg) is 55 ° C., and the weight average molecular weight (Mw). ) Was 32000.

<Preparation of aqueous dispersion of colorant particles (Cy1)>
90 parts by mass of sodium dodecyl sulfate was added to 1600 parts by mass of ion-exchanged water. While stirring this solution, 420 parts by mass of copper phthalocyanine (CI Pigment Blue 15: 3) was gradually added, and then dispersed using a stirrer "CLEARMIX" (manufactured by M Technique Co., Ltd.). Thus, an aqueous dispersion liquid (Cy1) of colorant particles was prepared.
In the obtained aqueous dispersion of colorant particles (Cy1), the volume-based median diameter of the colorant particles was 110 nm.

<Preparation of Toner 1>
(Aggregation / fusion process)
In a 5 liter stainless reactor equipped with a stirrer, a cooling pipe, and a temperature sensor, 6.0 parts by mass (solid content conversion) of "crystalline resin particle dispersion liquid (CA-2)", "crystalline resin" Particle dispersion (CB-1) "6.0 parts by mass (solid content conversion)," Amorphous polyester resin fine particle aqueous dispersion (PA-1) "76.0 parts by mass (solid content conversion), "Release agent particle dispersion liquid W-1" 6.0 parts by mass (solid content conversion), "Release agent particle dispersion liquid W-2" 6.0 parts by mass (solid content conversion), and "Colorant particle dispersion" 5 parts by mass (as solid content) was further added, 380 parts by mass of ion-exchanged water was further added, and the pH was adjusted to 10 using a 5 mol / L sodium hydroxide aqueous solution with stirring at 20 ° C. ..

Then, with stirring, an aqueous magnesium chloride solution prepared by dissolving 40 parts by mass of magnesium chloride hexahydrate in 40 parts by mass of ion-exchanged water was added dropwise over 10 minutes.
The internal temperature was raised to 80 ° C., the particle size was measured using Multisizer 3 (Beckman Coulter, Inc., aperture diameter; 50 μm), and when the volume-based median diameter reached 6.0 μm, An aqueous sodium chloride solution prepared by dissolving 160 parts by mass of sodium chloride in 640 parts by mass of ion-exchanged water was added. Further, while continuing heating and stirring, a flow type particle image measuring device “FPIA-2100” (manufactured by Sysmex Corporation) was used to adjust the internal temperature at a cooling rate of 15 ° C./min when the average circularity reached 0.960. It was cooled to 50 ° C. and then to 25 ° C. at a cooling rate of 8 ° C./min to obtain a dispersion liquid of “toner base particles 1”.

(Washing / drying)
The dispersion liquid of the toner base particles 1 produced in the aggregating / fusing step was subjected to solid-liquid separation using a basket type centrifuge to form a wet cake of the toner base particles. The wet cake was washed with deionized water at 35 ° C. until the filtrate had an electric conductivity of 5 μS / cm in the basket type centrifuge, and was then transferred to a “flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.)”. The toner was dried until the water content became 0.5% by mass to prepare "toner base particles 1".

(External additive processing step)
1 part by weight of hydrophobic silica (number average primary particle size = 12 nm) and 0.3 parts by weight of hydrophobic titania (number average primary particle size = 20 nm) were added to 100 parts by weight of the above-mentioned “toner base particle 1”. Then, the toner 1 was prepared by mixing with a Henschel mixer.

<Production of Toners 2 to 20>
Toners 2 to 20 were prepared in the same manner as the preparation of Toner 1, except that the types and addition amounts of the crystalline resin dispersion liquid and the amorphous polyester resin dispersion liquid to be added were changed as shown in Table 4 below. The toner 18 is a toner containing no non-hybrid crystalline polyester resin as a resin component. The toner 20 is a toner that does not contain a hybrid crystalline polyester resin as a resin component.
Toners 1 to 20 had a particle size in the range of 5.8 to 6.5 μm and an average circularity in the range of 0.958 to 0.965.

<Preparation of developer>
100 parts by mass of the ferrite core and 5 parts by mass of cyclohexyl methacrylate / methyl methacrylate (copolymerization ratio 5/5) copolymer resin particles were put into a high-speed mixer with stirring blades, and stirred and mixed at 120 ° C. for 30 minutes. A resin coating layer was formed on the surface of the ferrite core by the action of mechanical impact force, and a carrier having a volume-based median diameter of 40 μm was obtained.
The volume-based median diameter of the carrier was measured by a laser diffraction particle size distribution analyzer “HELOS” (manufactured by Sympatic) equipped with a wet dispersion machine. Toners 1 to 20 are added to the above carrier so that the toner concentration becomes 7% by mass, and the mixture is put into a micro type V mixer (Tsutsui Rikagaku Kikai Co., Ltd.) and mixed at a rotation speed of 45 rpm for 30 minutes to obtain a developer 1-20 were produced.

(Evaluation methods)
<< Method for observing cross section of toner base particles >>
<Observation conditions>
Device: Electron microscope "JSM-7401F" (manufactured by JEOL Ltd.)
Sample: Toner particle section dyed with ruthenium tetroxide (RuO ₄ ) (section thickness: 60 to 100 nm)
Accelerating voltage: 30kV
Magnification: 10000 times Observation conditions: Transmission electron detector, bright field image

<Method for making sections of dyed toner particles>
1 to 2 mg of toner was put in a 10 mL sample bottle so as to be spread, and after being treated under a ruthenium tetraoxide (RuO ₄ ) vapor dyeing condition as shown below, in a photocurable resin “D-800” (manufactured by JEOL Ltd.) And light-cured to form blocks. Then, using a microtome equipped with diamond teeth, an ultrathin sample having a thickness of 60 to 100 nm was cut out from the above block.
Then, the cut-out sample was treated again under the following treatment conditions and stained.

<Ruthenium tetroxide treatment conditions>
The ruthenium tetroxide treatment is performed using a vacuum electron dyeing device VSC1R1 (manufactured by Filgen KK). According to the apparatus procedure, a sublimation chamber containing ruthenium tetroxide was installed in the main body of the dyeing apparatus, and after introducing the toner or the ultrathin section into the dyeing chamber, the ruthenium tetroxide was dyed under the conditions of room temperature (24 to 25 ° C) and concentration. The treatment is performed under the conditions of 3 (300 Pa) and time of 10 minutes.

<Observation of dispersed particles>
After dyeing, the cells were observed with an electron microscope "JSM-7401F" (manufactured by JEOL Ltd.) within 24 hours.

<Method for measuring size of structural body, filamentous crystal structure, lamellar crystal structure (domain diameter, average major axis, average minor axis)>
The size (domain diameter) of the structure in the cross section of the toner base particles was calculated as the horizontal ferret diameter (FERE H).
Specifically, a cross section of the toner base particles produced in the same manner as above is photographed with a transmission electron microscope JEM-2000FX (manufactured by JEOL Ltd.) at an acceleration voltage of 80 kV at a magnification of 50,000, and a photographic image is scanned. And the horizontal ferret diameter (FERE H) of the structure was measured using an image processing analyzer LUZEX AP (manufactured by Nireco Corporation).

  Similarly, the major axis (major axis) of the thread-like crystal structure is the maximum length (MX LNG) instead of the horizontal ferret diameter (FERE H), and the minor axis (minor axis) is the horizontal ferret diameter (FERE H). ), The width (BR'DTH) was measured. The average domain diameter of the structure, and the average major axis and the minor axis of the thread-like crystal structure are measured by an arithmetic operation for 100 particles of the toner base particles in which the structure, the thread-like crystal structure and the lamella-like crystal structure are observed together. It was calculated as an average value.

<Cross-sectional Area Ratio of Structure, Filamentous Crystal Structure, Lamellar Crystal Structure and Release Agent>
The measurement was carried out by the same method as the method for measuring the size of the structure, the thread-like crystal structure, the lamella-like crystal structure and the release agent described above. The cross-sectional area ratio A of the structure to the cross-sectional area of the toner host particles, the cross-sectional area ratio B of the thread-like crystal structure to the cross-sectional area of the toner host particles, the cross-sectional area ratio C of the lamellar crystal structure to the cross-sectional area of the toner host particles, and the toner. The cross-sectional area ratio D of the release agent that does not form a structure with respect to the cross-sectional area of the base particles was measured using “Area AREA” of an image processing analyzer LUZEX AP (manufactured by Nireco Corporation). The area was measured in the area surrounded by the outer contour. This cross-sectional area ratio was also calculated as an arithmetic average value of 100 toner base particles in which a structure, a thread-like crystal structure, and a lamella-like crystal structure were observed together.

[Image forming method]
For image evaluation, a commercially available color multifunction machine "bizhub PRESS (registered trademark) C6000 (manufactured by Konica Minolta Co., Ltd.)" was used to prepare a modified machine A modified so that the fixing temperature, the toner adhesion amount and the system speed can be freely set. did. The developing device of the modified machine A was sequentially loaded with the toners 1 to 20 and the developer prepared above, and evaluated.

[Low temperature fixability (under offset)]
The evaluation was carried out in a fixing experiment in which a solid image having a toner adhesion amount of 8 g / m ² was fixed in an environment of normal temperature and humidity (temperature 20 ° C., humidity 50% RH). The temperature was set to be lower by 0 ° C., and the temperature of the upper fixing belt was changed from 110 ° C. so as to be increased in steps of 5 ° C., and repeated up to 20 ° C.
This experiment was conducted at a fixing speed of 300 mm / sec. The fixing temperature was evaluated twice as follows using A4 size NPI quality 127.9 g / m ² (manufactured by Nippon Paper Industries Co., Ltd.), and the average value is shown in Table 5.

Under-offset refers to an image defect in which the toner layer is peeled off from a transfer material such as recording paper when passing through a fixing device due to insufficient melting of the toner layer due to applied heat.
The lower limit fixing temperature of the upper fixing belt at which under-offset does not occur when an image is formed by the above method was evaluated and used as an index of low-temperature fixability. The lower the lower limit fixing temperature, the better the fixability, and a pass of less than 140 ° C. was accepted.

[Image gloss variation]
The fluctuation range of image glossiness when continuously printed under each environment was evaluated. An experiment was conducted to continuously print a solid image with a toner adhesion amount of 8 g / m ² under an environment of low temperature and low humidity (temperature 20 ° C., humidity 10% RH). 5000 sheets of A4 size NPI fine quality 127.9 g / m ² (manufactured by Nippon Paper Industries Co., Ltd.) were copied, and the first sheet and the 5000th sheet were measured. The glossiness was measured by using Micro-Gloss (75 °) manufactured by BYK Gartner, Inc., and the glossiness of each image was calculated by measuring at three points in the axial direction of the photoconductor and averaging. Specifically, the difference between the maximum value and the minimum value of the first sheet and the 5000th sheet was calculated, and 10% or less was regarded as a pass.

[In-flight pollution]
After the end of the fluctuation of the image glossiness, the door of the machine was opened to check the vicinity of the fixing device, and the presence or absence of the release agent adhered was visually ranked. The average in a low temperature and low humidity (temperature 20 ° C., humidity 10% RH) environment was calculated. Rank 2 or higher was passed.
Rank 1: There is adhesion, it cannot be used Rank 2: There is very little adhesion, it can be used somehow Rank 3: No adhesion, it can be used

  As can be seen from Table 5, the paper printed with the toner for developing an electrostatic latent image of the present invention improves low-temperature fixability while preventing contamination in the image forming apparatus, and changes in glossiness of the image. It turned out that it can suppress.

1 Crystalline Resin 2 Release Agent 3 Area (A)
4 areas (B)
5 areas (C)
6 Amorphous Polyester Resin 100 Image Forming Device 30 Image Processing Unit 40 Image Forming Unit 60 Fixing Device 411 Exposure Device 412 Developing Device 413 Photoconductor Drum 414 Charging Device D Original S Paper

Claims (6)

A toner for electrostatic latent image development comprising toner base particles containing at least a binder resin containing an amorphous polyester resin and a crystalline resin, and a release agent,
The toner base particles are particles formed by aggregating and fusing particles of the amorphous polyester resin, particles of the crystalline resin, and particles of the release agent,
The amorphous polyester resin is the main component of the binder resin,
As the crystalline resin, a crystalline polyester polymerized segment and an amorphous polyester polymerized segment are at least chemically bonded, a hybrid crystalline polyester resin, and a non-hybrid crystalline polyester resin, respectively, the binder resin and the The release agent is contained in the range of 2.75 to 7.5 parts by mass with respect to 100 parts by mass in total,
As the release agent, an ester wax and a paraffin wax are contained in the range of 3.0 to 12.5 parts by mass with respect to 100 parts by mass of the total amount of the binder resin and the release agent, respectively.
The toner base particles have a matrix region containing the amorphous polyester resin, and a domain region that exists in the matrix region in an isolated and dispersed manner.
The domain area, said the area crystalline resin and said release agent is contained structure in contact (A), the releasing agent filamentous crystals exist independently without contacting the A region (B) containing a crystalline resin forming a structure and a region (C) containing a crystalline resin forming a lamellar crystal structure independently existing without contact with the release agent (C). ) And a region (D) containing a release agent which independently exists without contacting the crystalline resin,
The toner in the region (A) of the total of the region (A + B + C) containing the crystalline resin and the region (D) containing the release agent which independently exists without contacting the crystalline resin. A toner for developing an electrostatic latent image, characterized in that the ratio (A / (A + B + C + D)) in the cross-sectional area of the base particles is in the range of 0.30 to 0.95 . The toner for developing an electrostatic latent image according to claim 1, wherein the average major axis of the region (B) is within a range of 200 to 2000 nm. The toner for developing an electrostatic latent image according to claim 1 or 2 , wherein an average domain diameter of the region (A) is within a range of 200 to 2500 nm. The toner for developing an electrostatic latent image according to any one of claims 1 to 3, wherein an average domain diameter of the region (C) is within a range of 100 to 2000 nm. The toner in the area (A) of the total of the area (A + B + C) containing the crystalline resin and the area (D) containing the release agent which independently exists without contacting the crystalline resin. The ratio (A / (A + B + C + D)) in the cross-sectional area of the base particles is in the range of 0.35 to 0.90, wherein the static particle according to any one of claims 1 to 4. Toner for developing electrostatic latent images. An image forming method, wherein an electrostatic latent image is formed by using the electrostatic latent image developing toner according to any one of claims 1 to 5 .

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