JP2003091101A - Electrostatic charge image developing toner, method of manufacturing this toner and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrostatic charge image developing toners which exhibit good chromaticity, have a high heat resistance, are low in fogging, have good OHP permeability and are odorless, a method of manufacturing these toners and an image forming method. SOLUTION: The electrostatic charge image developing toners are electrostatic charge image developing toners having toner particles containing a binder resin and coloring agents, in which the average Feret's horizontal diameter of the coloring agents in the toner particles is 10 to 500 nm, the ratio of the coloring agents having the Feret's horizontal diameter of 2 to 300 nm is >=50 number % and the coloring agents contain the compound expressed by the following general formula (1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge image developing toner used in copying machines, printers and the like, a method for producing the toner, and an image forming method using the toner.

[0002]

2. Description of the Related Art In recent years, with the demand for higher image quality, the size of toner particles has been reduced. However, it has been found that when the particle size is reduced, the resolution and sharpness of a full-color image are certainly in a satisfactory direction, but there are various influences associated with atomization. In addition, it has been found that when the toner particles are made small, the uneven distribution of the colorant forming the toner makes the charging characteristics more easily affected.

As a conventionally known toner having a small particle diameter, Japanese Patent Laid-Open No.
No. 000-214629 discloses that a polymerized toner obtained by a suspension polymerization method or an emulsion polymerization method can control the particle size and shape of the toner in a polymerization process in an aqueous medium, and has a small particle size distribution. It has been disclosed that a uniform toner having rounded corners can be obtained, and due to its fine line reproducibility and high resolution, it is attracting attention as a toner capable of reproducing small dot images for digital images.

However, the dispersibility of the colorant added to the toner tends to be inferior to the pulverized toner in the case of the polymerized toner. For example, when the polymerized toner is produced by using the suspension polymerization method, the monomer (monomer Polymerization is carried out after dispersing a pigment which is a colorant in (also referred to as a monomer), but the viscosity of the monomer droplets tends to increase as the polymerization progresses, so that there is a problem that aggregation of the colorant easily occurs. Further, when a polymerized toner is produced by using the emulsion polymerization method, there is a problem that the influence of pH or the like in the association, that is, the aggregation step promotes the aggregation of the colorant, and the colorant aggregation easily occurs.

As described above, the polymerized toner has a problem that the colorant is apt to agglomerate in the manufacturing process thereof and the dispersibility thereof is apt to deteriorate.

Particularly, in the multicolor image forming method, transparency is required to form a color image by superposing a plurality of color toners, and particularly when forming an image on an OHP film, a suitable transparency is obtained. Sex has become a serious problem.

Further, if the dispersibility of the colorant is poor, the odor of the toner, which is the final product, may be affected. Therefore, the dispersibility of the colorant is also desired from this viewpoint.

Further, after the image forming apparatus is stopped for a long time in a high temperature and high humidity environment, a state in which a toner having a changed charge amount due to absorption of water and a new toner are mixed with each other causes a halftone dot. When uneven density is generated on a halftone image, and in the formation of a multicolor image, the effect of the colorant added to the toner of each color developer is also added, which causes a difference in developability between each color developer and causes a color difference. It has the problem of causing expansion.

In view of the above problems, today, there is a demand for a toner having a better dispersibility of a colorant in a toner and exhibiting a well-balanced hue than conventional color toners. Has become.

In particular, various yellow colorants have been known so far, but benzidine-free is desired in view of the influence on the environment. Among them, as the colorant, a colorant having good chromaticity, high heat resistance, low fog, good OHP permeability, and no odor when incorporated in a toner is desired. .

As a conventionally known yellow colorant, for example, JP-A-10-171165 discloses a technique of using two kinds of yellow monoazo pigments having different structural formulas, and JP-A-2000-347459 discloses a technique. A technique for controlling the difference in charge amount between a yellow pigment and a yellow dye within a specific range is known.

However, even when the yellow colorant described above is used, it exhibits good chromaticity, high heat resistance, low fog, good OHP transparency, and no odor when incorporated in a toner. Things have not been obtained.

[0013]

The object of the present invention is to exhibit good chromaticity, high heat resistance, low fog, and OHP.
It is an object of the present invention to provide an electrostatic charge image developing toner having good transparency and no odor, a method for producing the toner, and an image forming method.

[0014]

The above objects of the present invention have been achieved by the following constitutions 1 to 15.

1. In an electrostatic charge image developing toner having toner particles containing a binder resin and a colorant, in the toner particles, the average horizontal Feret diameter of the colorant is 10 nm to 500.
The ratio of the colorant having a ferret horizontal diameter of 2 nm to 300 nm is 50% by number or more, and the colorant contains the compound represented by the general formula (1). Toner for developing electrostatic images.

2. 2. The toner for developing an electrostatic charge image as described in 1 above, wherein the toner particles are produced by using a colorant dispersed in a water-based dispersion medium to have a weight average particle diameter of 2 nm to 300 nm.

3. The binder resin and the colorant have toner particles forming a sea-island structure, and the average area of Voronoi polygons formed by vertical bisectors between the centers of gravity of adjacent islands in the toner particles. Value is 20000 nm ^{2 to} 1200
3. The toner for developing an electrostatic charge image as described in 1 or 2 above, which has a size of 00 nm ² and a coefficient of variation of the area of the Voronoi polygon is 25% or less.

4. The binder resin and the colorant have toner particles forming a sea-island structure, and the average area of Voronoi polygons formed by vertical bisectors between the centers of gravity of adjacent islands in the toner particles. Value is 40,000 nm ^{2 to} 1000
00 nm ² , and the variation coefficient of the area of the Voronoi polygon is 20% or less, 1 to 3 above
5. The toner for developing an electrostatic charge image according to any one of 1.

5. The binder resin and the colorant have toner particles forming a sea-island structure, and the average area of Voronoi polygons formed by vertical bisectors between the centers of gravity of adjacent islands in the toner particles. Value is 20000 nm ^{2 to} 1200
A nm ^2, and the island to form a Voronoi polygons having an area of the Voronoi polygon having 160000Nm ² or more areas, characterized in that a 3% by number to 20% by number of the total island 1 5. The toner for developing an electrostatic charge image according to any one of items 4 to 4.

6. 6. The static toner according to any one of 1 to 5 above, wherein the ratio of toner particles having no corners to all toner particles is 50 number% or more, and the number variation coefficient in the number particle size distribution is 27% or less. Toner for charge image development.

7. The ratio of toner particles having a shape factor in the range of 1.01 to 1.6 to all toner particles is 65 number% or more, the variation coefficient of the shape factor is 16% or less, and the number variation coefficient in the number particle size distribution. Is 27% or less, The toner for developing an electrostatic charge image according to any one of 1 to 6 above.

8. When the toner for developing an electrostatic charge image according to any one of 1 to 7 above is produced, the method has a step of producing a binder resin by polymerizing a polymerizable monomer in an aqueous medium. A method for producing a toner for developing an electrostatic charge image.

9. In producing the toner for developing an electrostatic charge image according to any one of 1 to 7, the toner particles are produced through a step of aggregating and fusing the binder resin particles in an aqueous medium. And a method for producing a toner for developing an electrostatic image.

10. In producing the toner for developing an electrostatic charge image according to any one of 1 to 7 above, the toner particles include binder resin particles formed by polymerizing a polymerizable monomer, and colorant particles. A method for producing a toner for developing an electrostatic charge image, which is produced through a step of salting out / fusing.

11. In producing the toner for developing an electrostatic charge image according to any one of 1 to 7 above, the toner particles salt out / fuse the binder resin particles obtained by the multistage polymerization method and the colorant particles. A method for producing an electrostatic charge image developing toner, characterized in that the toner is produced through steps.

12. In producing the toner for developing an electrostatic charge image according to any one of 1 to 7 above, toner particles are provided on the surface of the colored particles containing a resin and a colorant,
A method for producing a toner for developing an electrostatic charge image, which is produced by a step of fusing binder resin particles by a salting out / fusing method to form a binder resin layer.

13. 13. An electrostatic charge image developing toner manufactured by using the method for manufacturing an electrostatic charge image developing toner according to any one of 8 to 12.

14. An image forming method comprising a step of converting an electrostatic latent image formed on a photoconductor into a visible image, transferring the visible image onto a recording medium, and heating and fixing the image, wherein the heating and fixing includes a film having an endless belt shape. The image forming method is performed by using the toner for developing an electrostatic charge image described in any one of 1 to 7 and 13 above.

15. 14. The electrostatic latent image is formed by irradiating a photoconductor with digital exposure.
The image forming method described in 1 ..

The present invention will be described in detail below. The present inventors have examined various problems described above, and as a result, claim 1
In the toner for developing an electrostatic charge image having toner particles containing a binder resin and a colorant, the average horizontal diameter of the Feret of the colorant is 10 nm to 500 nm, and all the particles of the colorant are contained. And the proportion of the colorant having a ferret horizontal diameter of 2 nm to 300 nm is 50% by number or more,
In addition, by containing the compound represented by the general formula (1) in the colorant, it exhibits good chromaticity, high heat resistance, low fog, good OHP permeability, and
It has been found that it is possible to provide a toner for developing an electrostatic charge image having no odor, a method for producing the toner, and a method for forming an image.

The colorant according to the present invention will be described. The colorant according to the present invention has a ferret average horizontal diameter of 10 nm to 5
00 nm, and 2 nm to 3 among all particles of the colorant.
The proportion of the colorant having a ferret horizontal diameter of 00 nm is 5
It is necessary that the content is 0% by number or more, and the colorant contains the compound represented by the general formula (1).

From the viewpoint that the effect described in the present invention can be more preferably obtained, the average horizontal Feret diameter of the colorant is 50 nm to 30.
It is preferably 0 nm. In the toner particles, the proportion of the colorant having a ferret horizontal diameter of 2 nm to 300 nm is preferably 60 number% or more,
More preferably, it is 80% by number to 100% by number.

<< Ferret Horizontal Diameter of Colorant >> The ferret horizontal diameter used in the present invention represents the horizontal length of toner particles when the toner particles are placed horizontally in an arbitrary state. The ferret horizontal diameter of the colorant represents the horizontal length of each colorant present inside the toner particles arbitrarily placed in this manner. Further, the average ferret horizontal diameter of the colorant is an average value of at least 100 ferret horizontal diameters in the toner particles.

From the viewpoint of suppressing the occurrence of offset, the variation coefficient of the Feret horizontal diameter of the colorant in the toner particles according to the present invention is preferably 40% or less, and more preferably 3.
It is 5% or less, particularly preferably 30% or less. The variation coefficient of the Feret horizontal diameter of the colorant in the toner particles is obtained by the following formula.

Variation coefficient of ferret horizontal diameter = {S2 / K2}
× 100 (%) In the formula, S2 represents the standard deviation of the ferret horizontal diameter of 100 colorants, and K2 represents the average value of the ferret horizontal diameter.

In the present invention, the coefficient of variation of the ferret horizontal diameter of the colorant in the toner particles means the variation of the average value of the ferret horizontal diameter, the size of the island containing the colorant when the binder resin is sea. It represents the variation of.

Further, in the present invention, it is possible to more preferably obtain the effect described in the present invention when the coefficient of variation is 40 or less. However, when the value of the coefficient of variation is 0, that is, in the ferret horizontal diameter, It is not necessary that there be no variation.

The data such as the average horizontal diameter of Feret's colorant and the horizontal diameter of Feret's colorant in the toner particles described above can be obtained by observing with a conventionally known transmission electron microscope apparatus, photographing a particle photograph, and analyzing an image. . As the transmission electron microscope, a model well known to those skilled in the art is usually observed sufficiently, and for example, LEM-2000 type (manufactured by Topcon Corporation), JEM-2000FX (manufactured by JEOL Ltd.) and the like are used.

In the present invention, 10 times at a magnification of 10,000 times.
Data such as the average horizontal diameter of the ferret and the horizontal diameter of the ferret were calculated from the results of transmission electron micrographs of the number of islands in the toner particles, which is the feature of the present invention, from the projection plane of 00 or more toner particles. .

As a photographing method using a transmission electron microscope, a generally known method used when measuring toner particles is used, that is, as a concrete method for measuring the tomographic plane of the toner, a room temperature curable epoxy is used. After the toner is sufficiently dispersed in the resin, it may be embedded and cured, and the particle size may be 100 nm.
After dispersing in styrene fine powder of about
The resulting block was dyed with ruthenium tetroxide or osmium tetroxide in combination, and a microtome equipped with diamond teeth was used to cut out flaky samples and use a transmission electron microscope (TEM). , Take a photograph of the tomographic morphology of the toner. From the obtained photograph, the shape of the region of the crystalline compound in the toner particles was visually confirmed, and the image was taken by the image processing apparatus "Luzex F" (manufactured by Nireco Corp.) provided in the electron microscope apparatus. By performing arithmetic processing on the image information, values such as the average horizontal Feret diameter, the horizontal Feret diameter, the number, and the shape coefficient of the colorant existing as islands in the toner particles can be obtained.

The colorant relating to the toner of the present invention has a weight average particle diameter of 2 nm to 2 nm in the aqueous dispersion medium during the toner manufacturing process.
A colorant (also referred to as colorant fine particles) dispersed in a fine particle state of 300 nm is used to be added to the toner particles, and preferably dispersed in the range of 2 nm to 200 nm.

Here, the "aqueous dispersion medium" means 50% by mass to 100% by mass of water and 0% by mass to 5% of a water-soluble organic solvent.
A medium consisting of 0 mass%. Examples of the water-soluble organic solvent include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran, and alcohol-based organic solvents that do not dissolve the obtained resin are preferable. The weight average particle diameter of the colorant dispersed in the aqueous dispersion medium in the form of fine particles can be measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

The method for preparing the colorant particles according to the present invention into colorant fine particles having the above-mentioned weight average particle diameter will be described in detail below.

[Production of Colorant Fine Particles] The colorant fine particles used for obtaining the toner of the present invention are formed by using a dispersing device for finely dispersing the colorant fine particles in an aqueous medium containing a surfactant. It is what is done. That is, FIG.
The dispersing device shown in (1) is an example of a dispersing device that finely disperses the colorant fine particles that are preferably used in the toner of the present invention. Then, by the action of the shearing force (further, the action of collision force, pressure fluctuation, cavitation, and potential core), the colorant is finely dispersed in the aqueous medium containing the surfactant to obtain fine particles.

Here, the surfactant contained in the aqueous medium in which the colorant particles are dispersed has a critical micelle concentration (CMC).
The surfactant is dissolved at the above concentration, and the same surfactant as that used in the polymerization step can be used as the surfactant.

The weight average particle diameter (dispersed particle diameter) of the colorant fine particles is 2 nm to 300 nm, preferably 2 nm to 300 nm.
It is 200 nm. The weight average particle size of the colorant particles is 1
If the thickness is less than 0 nm, the colorant will be violently suspended in the water system, and if the weight average particle size exceeds 300 nm, the colorant particles will not be appropriately dispersed in the water system and will easily settle. In addition, it becomes difficult to introduce the colorant into the toner particles, and the colorant particles are not incorporated into the toner particles and remain free in the aqueous system, which is not preferable.

The colorant fine particles used in the toner of the present invention are prepared by adding the colorant into an aqueous medium containing a surfactant, and then first preliminarily dispersing (coarsely dispersing) it with a propeller stirrer or the like. A predispersion liquid in which agglomerated particles are dispersed is produced. A preferable dispersion state is obtained by supplying the preliminary dispersion liquid to an agitator equipped with a screen for partitioning and forming an agitator chamber and a rotor rotating at high speed in the agitator chamber, and performing a dispersion treatment (fine dispersion treatment) by the agitator. A dispersion of fine colorant particles having is prepared.

In the present invention, as a stirring device for dispersion treatment for obtaining colorant fine particles having a preferable dispersion state, "CLEAR MIX" (manufactured by M Technique Co., Ltd.) can be mentioned. This "Clearmix" has a rotor (stirring blade) that rotates at high speed and a fixed screen (fixed ring) that surrounds the rotor, and applies shear force, collision force, pressure fluctuation, cavitation and It has a structure that imparts the action of a potential core, and these actions act synergistically to effectively emulsify and disperse the liquid to be treated.

That is, this "CLEAR MIX" is originally used for forming an emulsion (dispersion of liquid fine particles), but the present inventors have used for dispersing solid colorant fine particles in an aqueous medium. It was found that a dispersion of colorant fine particles having a preferable average particle size and a sharp particle size distribution can be obtained by using it as an apparatus.

FIG. 1A is a schematic view showing a rotor rotating at a high speed and a fixed screen surrounding the rotor. In FIG. 1A, 101 is a screen and M is a stirrer formed by the screen 101. A chamber and 102 are rotors that rotate at high speed in the stirring chamber M.

The rotor 102 is a stirring blade that rotates at a high speed, and its rotation speed is usually 4,500 to 22,000 rpm.
And preferably 10,000 to 21,500 rpm. The tip peripheral speed of the rotor 2 is usually 10 to 40 m / s.
ec, preferably 15 to 30 m / sec.

The screen 101 arranged so as to surround the rotor 102 is composed of a fixed ring composed of a large number of slits (not shown). The width of the slit is 0.5-5 mm
And preferably 0.8 to 2 mm. The number of slits is 10 to 50, preferably 15 to 30.
The clearance between the rotor 102 and the screen 101 is usually 0.1 to 1.5 mm, preferably 0.2.
~ 1.0 mm.

The average particle size and particle size distribution of the colorant fine particles are adjusted by controlling the rotation speed of the rotor 102, and can also be adjusted by selecting the shapes of the screen 101 and the rotor 102. Specifically, a screen (S1.0-24, S1.0-24, S1.0
1.5-24, S1.5-18, S2.0-18, S
3.0-9) and the rotors (R1 to R4) are combined to obtain a preferable dispersion state, but it is also possible to manufacture the resin by itself to obtain a more preferable dispersion state.

FIG. 1B is a schematic view showing a continuous processing apparatus (Clearmix) equipped with a rotor and a screen. The pre-dispersed dispersion liquid (pre-dispersion liquid) is supplied to the stirring chamber between the screen 101 and the rotor from the pre-dispersion liquid inlet 104 shown in FIG. The screen 101 and the rotor include a pressure vacuum attachment 10
It is surrounded by 3, and a temperature sensor 106, a cooling jacket 107 and a cooling coil 108 are arranged. The aggregated particles of the colorant in the pre-dispersion liquid are crushed (finely dispersed) by applying a shearing force generated by the rotor rotating at a high speed and the screen 101.

That is, the colorant agglomerated particles in the pre-dispersion liquid supplied to the zone-shaped stirring chamber between the screen 101 and the rotor are subjected to shearing force (mechanical force) generated by high-speed rotation of the screen 101 and the rotor. Energy), and in addition to shearing force, it is disintegrated (finely dispersed) by the action of collision force, pressure fluctuation, cavitation, and potentiation core to become fine colorant particles. The dispersion liquid of fine colorant particles is ejected from the slit of the screen 101 into the pressure vacuum attachment 103 to obtain a dispersion liquid of fine colorant fine particles having a preferable average particle size and a sharp particle size distribution. The dispersion liquid containing the colorant fine particles is sent from the dispersion liquid outlet 5 to the next step.

By the action of the rotor and the screen, the colorant agglomerated particles are crushed in the stirrer to form colorant fine particles (dispersed particles) having a preferable average particle size and a sharp particle size distribution. , Due to a plurality of actions described below.

(1) Since the velocity gradient is large near the surface of the rotor (stirring blade) that rotates at high speed, a high shear rate region is formed near the surface, and the shearing force generated in this region causes the aggregated particles of the colorant to be released. Be crushed.

(2) Behind the rotor (stirring blade), if the rotation speed is high, a vacuum portion (cavitation) is generated, and the bubbles generated by the rotation are extinguished at the stage when the flow velocity of the dispersion liquid decreases. An impact pressure is generated as the bubbles are compressed, and the impact pressure causes the aggregated particles of the colorant to be crushed.

(3) The rotor (stirring blade) imparts pressure energy to the pre-dispersion liquid by its high speed rotation, but when the pressure energy is suddenly released, the kinetic energy of the pre-dispersion liquid increases and the pre-dispersion liquid flows by the rotor. When the liquid repeatedly passes between the open part (slit part) and the closed part (non-slit part) of the screen, the pressure energy is fluctuated to generate a pressure wave and break up the agglomerated particles of the colorant. Let

(4) When the predispersion liquid having a large kinetic energy collides with the screen or other wall, the agglomerated particles of the colorant which have received a collision force are crushed, and the colorant fine particles having a sharp particle size distribution. Becomes

(5) When the dispersion liquid having velocity energy passes through the slit portion of the screen, it becomes a jet flow (jet flow). In the potential core (velocity region not affected by viscous flow) in the jet, the surrounding fluid is sucked at a high velocity. Agglomerated particles of the colorant that have received this energy are crushed to form colorant fine particles having a sharp particle size distribution.

The dispersion time for obtaining the colorant fine particle dispersion is not particularly limited, but is 5 to 30 minutes.
It is preferably 7 to 25 minutes. When circulating, the number of passes is preferably 5 or more, more preferably 5 to 20. If the dispersion time is too long, the dispersion becomes excessive and the abundance of fine particles increases, which is not preferable.

In order to obtain colorant fine particles preferably used in the toner of the present invention, a dispersion container equipped with a stirrer equipped with a screen and a rotor is used in an aqueous medium contained in the dispersion container. Alternatively, a batch-type dispersion treatment in which a colorant (an aqueous medium containing the colorant) is jetted from the stirring chamber of the stirring device may be performed.

FIG. 1C is a schematic view showing a dispersion container equipped with such a stirring device (Clearmix).
Distributed processing is performed by such an apparatus. Figure 1 (c)
, 111 is a dispersion container, 112 is a stirrer, 11
Reference numeral 3 is a stirring shaft for driving the stirring device 112. The stirring device 112 has the same structure (screen and rotor) as that shown in FIG.

Pre-dispersion (dispersion of aggregated particles of colorant)
Is a strong shearing force generated between the rotor and the screen, which enters the stirring chamber from the upper part of the stirring device 112 and rotates at high speed,
Stirred by impact force and turbulence, the weight average particle size is 3
Colorant fine particles of 0 to 300 nm are formed and jetted into the dispersion container 111 from the slit of the screen. In the step of dispersing the colorant fine particles, the dispersion container 111 may have a jacket structure, and hot water or steam, and if necessary, cold water may be flown into the jacket to control the temperature inside the dispersion container 111.

In the case of carrying out the dispersion treatment using the dispersion container shown in FIG. 1 (c), the jetting direction of the colorant from the stirring chamber of the stirrer 112 (the jetting direction of the colorant fine particles into the aqueous medium). Is preferably in the downward or horizontal direction. By jetting the colorant (colorant fine particles) in the downward or horizontal direction, the aqueous medium in the dispersion container 111 flows as indicated by the arrow F. As a result, the colorant is jetted downward and its flow is along the wall. It rises and then circulates again into the clear mix. Therefore, the dispersion process can be reliably repeated, and the dispersion energy can be uniformly applied. As a result, it is presumed that the dispersion diameter of the colorant can be made uniform. This makes it possible to efficiently form fine colorant particles having a sharp particle size distribution.

In this way, the colorant particles preferably used in the present invention are crushed by the action of the shearing force generated by the screen and the rotor, and the colorant agglomerated particles have a suitable average particle size (weight average particle size). : 30 to 500 nm) and sharp particle size distribution (standard deviation (σ) is 30 or less)
A dispersion liquid of colorant fine particles (fine particles close to primary particles) having is obtained. By subjecting such colorant fine particles (dispersed particles) to salting out / fusing with resin fine particles, inside of toner particles formed The colorant fine particles are surely introduced into the toner, the introduced colorant particles are not released, and the content ratio of the colorant does not vary among the toner particles.

As a result, even when the toner of the present invention is subjected to image formation under high temperature and high humidity or after a long period of non-use of the apparatus, image defects such as fog and dust of fine dots due to fluctuation of toner charge amount are caused. It does not occur. Further, in the present invention, since the colorant fine particles are dispersed in the toner particles without using the medium, image defects caused by remaining fine impurities such as crushed pieces of the medium in the toner do not occur.

The colorant particles are subjected to salting out / fusion treatment in a state of being dispersed in an aqueous medium. The aqueous medium in which the colorant particles are dispersed is preferably an aqueous solution in which the surfactant is dissolved at a concentration equal to or higher than the critical micelle concentration (CMC).

The disperser used for the dispersion treatment of the colorant particles is not particularly limited, but preferably a stirring device "CLEARMIX (CLEAR) equipped with a rotor rotating at high speed.
MIX) ”(manufactured by M Technique Co., Ltd.), ultrasonic disperser, mechanical homogenizer, manton-goulin, pressure homogenizer such as pressure homogenizer, and medium type disperser such as Getzman mill and diamond fine mill.

In order to salt out / fuse the composite resin particles and the colorant particles, the salting out agent (aggregating agent) having a critical coagulation concentration or higher is added to the dispersion liquid in which the composite resin particles and the colorant particles are dispersed. ) Is added and the dispersion is heated to the glass transition temperature (Tg) or higher of the composite resin particles.

The temperature range suitable for salting out / fusing is (Tg + 10) to (Tg + 50 ° C.), and particularly preferably (Tg + 15) to (Tg + 40 ° C.). In addition, an organic solvent infinitely soluble in water may be added in order to effectively carry out the fusion.

In the present invention, the resin particles and the colorant are salted out, aggregated and fused in an aqueous medium to obtain colored particles (in the present invention, referred to as toner particles). When separated from the medium, it is preferably carried out at a temperature not lower than the Kraft point of the surfactant present in the aqueous medium, and more preferably at a temperature range of Kraft point to (Craft point + 20 ° C.). is there.

The Kraft point is the temperature at which the aqueous solution containing the surfactant begins to turn cloudy, and the Kraft point is measured as follows.

<Measurement of Kraft Point> An aqueous medium used in the salting-out, aggregating, and fusing steps, that is, a surfactant solution, was mixed with an actually used amount of an aggregating agent to prepare a solution, and this solution was cooled to 1 ° C. Stored for 5 days. The solution was then heated slowly with stirring until it became transparent. The temperature at which the solution became clear is defined as the Kraft point.

From the viewpoint of suppressing excessive charging of the toner particles and imparting uniform charging properties, the toner for developing an electrostatic charge image of the present invention comprises, in particular, in order to stabilize and maintain the charging properties with respect to the environment. Metal element described above (as a form, metal,
250 to 20 in the toner)
The content is preferably 000 ppm, more preferably 800 to 5000 ppm.

The compound represented by the general formula (1) according to the present invention will be described. In the general formula (1),
₁ carbon atom represented by X ₁ , X ₂ , X ₃ , Y ₁ , Y ₂ and Y ₃
The alkyl groups of to 3 may be unsubstituted or may have a substituent, and examples thereof include a methyl group, an ethyl group, an isopropyl group and a propyl group.

In the general formula (1), X ₁ , X ₂ , X ₃ ,
Examples of the fluoroalkyl group having 1 to 3 carbon atoms represented by Y ₁ , Y ₂ and Y ₃ include a methyl group, an ethyl group, an isopropyl group and a propyl group each having at least one fluorine atom. The above group may further have a substituent.

In the general formula (1), X ₁ , X ₂ , X ₃ ,
The alkoxyl group represented by Y ₁ , Y ₂ and Y ₃ may be unsubstituted or may have a substituent.
Examples thereof include a methoxy group, an ethoxy group and a propoxy group.

In the general formula (1), X ₁ , X ₂ , X ₃ ,
Examples of the pigeon source atom represented by Y ₁ , Y ₂ and Y ₃ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

In the general formula (1), X ₁ , X ₂ , X ₃ ,
Examples of the higher amine salt of the sulfo group represented by Y ₁ , Y ₂ and Y ₃ include amines having 4 or more carbon atoms, such as butylamine, cyclohexylamine, naphthylamine, aniline, anisidine, phenetidine, toluidine and xylidine. To be

In the general formula (1), X ₁ , X ₂ , X ₃ ,
Examples of the alkoxycarbonyl group represented by Y ₁ , Y ₂ and Y ₃ include a methoxycarbonyl group and an ethoxycarbonyl group.

In the general formula (1), X ₁ , X ₂ , X ₃ ,
As —CONHR ₁ represented by Y ₁ , Y ₂ and Y ₃ , R
Examples of the alkyl group having 1 to 8 carbon atoms represented by ₁ include a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group and an octyl group.

In the general formula (1), X ₁ , X ₂ , X ₃ ,
As -NHCOR ₂ represented by Y ₁ , Y ₂ and Y ₃ , R
_The alkyl group represented by ₂ , for example, a methyl group,
Examples thereof include ethyl group, propyl group, pentyl group, hexyl group, octyl group and decyl group.

In the general formula (1), X₁, X₂, X₃,
Y₁, Y₂And Y₃Represented by -SO ₂R₃As R₃so
Examples of the alkyl group having 1 to 8 carbon atoms represented include, for example,
Methyl, ethyl, propyl, pentyl, hex
Group and octyl group.

Specific examples of the compound represented by formula (1) are shown below, but the invention is not limited thereto.

[0087]

[Chemical 2]

The compound represented by the general formula (1) according to the present invention can be synthesized by a conventionally known method for synthesizing a monoazo pigment or JP-A-10-
It can be synthesized by referring to the method described in No. 171165 or the like.

The content of the compound represented by the general formula (1) in the colorant according to the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably It is 80% by mass to 100% by mass.

Further, in the present invention, the following colorants can be used. The electrostatic image developing toner of the present invention (hereinafter, also simply referred to as toner) is preferably produced by salting out / fusing the binder resin particles and the colorant particles. Examples of the colorant (colorant particles to be salted out / fused with resin particles) constituting the toner of the present invention include various inorganic pigments, organic pigments and dyes. As the inorganic pigment, conventionally known ones can be used. Specific inorganic pigments are exemplified below.

Examples of black pigments include furnace black, channel black, acetylene black,
Carbon black such as thermal black and lamp black, and magnetic powder such as magnetite and ferrite are also used.

These inorganic pigments can be used alone or in combination of two or more as desired. Further, the amount of the pigment added is 2 to 20% by mass, preferably 3 to 15% by mass, based on the polymer.

When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, from the viewpoint of imparting a predetermined magnetic characteristic, 20 to 6 is contained in the toner.
It is preferable to add 0% by mass.

Conventionally known organic pigments and dyes can be used, and specific organic pigments and dyes are exemplified below.

As the magenta or red pigment,
For example, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I.
Pigment Red 6, C.I. I. Pigment Red 7,
C. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I.
I. Pigment Red 53: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I.
Pigment Red 149, C.I. I. Pigment Red 1
66, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222
Etc.

Examples of pigments for orange or yellow include C.I. I. Pigment Orange 31, C.I.
I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I.
Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 9
4, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 1
85, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 156 and the like.

As the pigment for green or cyan,
For example, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 1
5: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

Examples of dyes include C.I. I. Solvent Red 1, 49, 52, 58, 63,
111, 122, C.I. I. Solvent yellow 1
9, the same 44, the same 77, the same 79, the same 81, the same 82, the same 9
3, ibid 98, ibid 103, ibid 104, ibid 112, ibid 16
2, C.I. I. Solvent Blue 25, 36, 60,
No. 70, No. 93, No. 95 and the like can be used, and a mixture thereof can also be used.

These organic pigments and dyes can be used alone or in combination of two or more as desired.
The amount of pigment added is 2 to 20% by mass based on the polymer.
And preferably 3 to 15% by mass.

The colorant (colorant particles) constituting the toner of the present invention may be surface-modified. As the surface modifier, conventionally known ones can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used. Examples of the silane coupling agent include alkoxysilanes such as methyltrimethoxysilane, phenyltrimethoxysilane, methylphenyldimethoxysilane and diphenyldimethoxysilane, siloxanes such as hexamethyldisiloxane, γ-chloropropyltrimethoxysilane and vinyltrisilane. Chlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
γ-ureidopropyltriethoxysilane and the like can be mentioned. As the titanium coupling agent, for example, TTS, 9S, 38S, 41B, 46B, 55, 138, which is commercially available under the trade name "Planeact" manufactured by Ajinomoto Co., Inc.
Commercial products A-1, B- manufactured by Nippon Soda Co., Ltd. such as S, 238S.
1, TOT, TST, TAA, TAT, TLA, TO
G, TBSTA, A-10, TBT, B-2, B-4,
B-7, B-10, TBSTA-400, TTS, TO
A-30, TSDMA, TTAB, TTOP and the like can be mentioned. As the aluminum coupling agent, for example,
Examples include "Planeact AL-M" manufactured by Ajinomoto Co., Inc.

The amount of these surface modifiers added is preferably 0.01 to 20% by mass, more preferably 0.1 to 5% by mass, based on the colorant. In addition, as a method for modifying the surface of the colorant particles, a method of adding a surface modifier to the dispersion liquid of the colorant particles and heating the system to react them can be mentioned. Colorant particles surface-modified in this way,
It is obtained by collecting by filtration, repeating washing treatment with the same solvent and filtration treatment, and then drying treatment.

The toner particles according to the present invention preferably have a sea-island structure, and the sea-island structure means a structure in which an isolated island phase exists in the continuous phase. That is, in the toner for developing an electrostatic image of the present invention, the respective components of the binder resin and the colorant forming the toner particles do not mix with each other,
It is preferable that each independently forms a phase, and as a result, one having a sea-island structure is preferably used.

The toner particles according to the present invention preferably have a structure in which the colorant islands are present in the continuous phase (sea) of the resin.

The toner particles according to the present invention have a sea-island structure. That is, the cross-sectional photograph taken by a transmission electron microscope shows that the toner particles have a brightness in the sea area and the island area. It is confirmed by being shown with different areas of. That is, it is confirmed by a transmission electron microscope that there are granular islands (colorant phase) having different brightness in the continuous phase (binder resin phase). Further, from the results of observation with an electron microscope, it is possible to obtain numerical factors such as the number of islands in one toner particle and the shape factor of the island, which specify the sea-island structure in the toner particle.

Luminance in a transmission electron microscope is caused by visualizing the difference in electron beam transmissivity caused by each element constituting the toner particles, that is, the binder resin and the colorant, and is generally Since the colorant has a lower electron beam transmittance than the binder resin, it is photographed at low brightness.

In the electron micrograph, low brightness means 0 when the brightness signal of a pixel is divided into 256 gradations.
~ 99 gradations, and medium brightness is 80 ~ 160
The one in the range of gradation and the one having high brightness mean the one in 127 to 255 gradations, but in the present invention, relative ones, that is, the constituents of the toner described above may be discriminated from each other by the photograph, and are not necessarily colored. It is not essential that the brightness of the agent is within the low brightness range defined in the above range.

In this way, according to the present invention, each constituent element in the toner particles is identified based on the brightness,
The sea is the sea, and the islands are islands that can be visually identified and identified by electron micrographs. An image that can be visually identified by the image analysis device installed in the electron microscope device. It is converted into information.

FIGS. 2A and 2B are schematic views showing an example of toner particles having a sea-island structure. In an electron micrograph, toner particles having a sea-island structure are shown in this schematic view. Thus, it is confirmed that it is composed of a continuous phase and islands.

Further, the length a along the outer periphery of the toner particles,
It is also confirmed that there is a region having no depth b islands.

Further, in FIG. 2, it was confirmed that, as the islands in the toner particles, the islands of the colorant and the binder resin, which is a constituent element of the toner, also form an island structure in the continuous phase. It

As a transmission electron microscope apparatus for observing the structure of toner particles according to the present invention, a model well known to those skilled in the art is often observed sufficiently, for example, "LEM-200".
Type 0 (manufactured by Topcon) "and the like are used. In the present invention,
From the projection surface of 1,000 or more toner particles at a magnification of 10,000 times, the number of islands in the toner particles having a sea-island structure was calculated from the results of transmission electron micrographs.

In the present invention, the photographing method using a transmission electron microscope is carried out by a generally known method used for measuring toner particles. That is, as a specific method for measuring the tomographic plane of the toner, the toner may be sufficiently dispersed in an epoxy resin that is curable at room temperature and then embedded and cured, or dispersed in styrene fine powder having a particle diameter of about 100 nm. After applying pressure, the resulting block was dyed with ruthenium tetroxide or osmium tetroxide in combination, and then a flaky sample was prepared using a microtome equipped with diamond teeth. The cut-out transmission electron microscope (TEM) was used to photograph the tomographic morphology of the toner.
The shape of the region of the colorant in the toner particles is visually confirmed from the photograph, and the image information photographed by the image processing device “Luzex F” (manufactured by Nireco Corporation) provided in the electron microscope device. Is calculated by
The characteristics of the island portion in the toner particles can be obtained.

The structure of the toner particles according to the present invention is specified by the above method. Hereinafter, the factors that specify the structure of the toner particles according to the present invention will be described in detail.

The island of the colorant component present in the toner particles according to the present invention is shown as island B in the schematic view of FIG. As is clear from this schematic diagram, in the toner particles having a sea-island structure, islands of other toner constituent elements may be present in addition to islands of the colorant component. Since the brightness is different from that of the other islands, they can be easily identified in the electron micrograph. The island of the colorant component in the toner particles according to the present invention is specified based on the area of the Voronoi polygon described below.

The numerical value for specifying the island portion in the sea-island structure in the toner particles according to the present invention is calculated by the image analysis device attached to the electron microscope device based on the image information observed by the electron microscope device.

The area of the Voronoi polygon used in the present invention indicates the occupancy of the island portion in the toner particles. Voronoi polygon or Voronoi polyhedron is
For example, as published in Iwanami Physics and Chemistry, by creating vertical bisectors or vertical bisectors of adjacent points when many points are dispersed in space or on a plane. The entire space is divided into polyhedra, or the entire plane is divided into polygons, the polyhedrons formed in this way are called Voronoi polyhedra, the polygons are called Voronoi polygons, and such division of spaces or planes is called Voronoi division. . FIG. 3 shows an example of toner particles according to the present invention divided by Voronoi polygons.

As described above, in the present invention, the area occupied by the islands in the sea-island structure of the toner particles is represented by the Voronoi polygonal area obtained by Voronoi division as a measure of the ratio of the islands in the toner particles. It is a thing. That is, in the present invention, attention is paid to the center of gravity of the islands present in the toner particles, polygons are formed by vertical bisectors formed by connecting the centers of gravity of adjacent islands, and the area of these polygons is transmitted. It is calculated by the image analysis device installed in the electron microscope device based on the result of the photograph taken by the scanning electron microscope.

The large area of the Voronoi polygon means that
This indicates that the centers of gravity of adjacent islands are far apart from each other, that is, the islands in the particles are sparsely occupied. Also, a small Voronoi polygon area means that the distance between the centers of gravity of adjacent islands is short and close to each other, that is, the islands in the particles are densely occupied. It is a thing. In the present invention, the Voronoi polygon of the island portion in the toner particles is measured for 1000 toners, and the average value per toner particle is calculated.

A general definition of a Voronoi polygon is mathematically defined by the following equation.

<< Area of Voronoi Polygon >> Two-dimensional space R
N independent points P in a two- or three-dimensional space R3
(I) Voronoi polygon V (i) for (1 ≦ i ≦ N)
V (i) = {X || X-P (i) | <| X-P (j) | for all i to j} where X and P are position vectors, respectively. | | Indicates a distance in Euclidean space.

It is assumed that V (i) thus defined forms a Voronoi polygon at R2 and a Voronoi polyhedron at R3, and when V (i) and V (j) are adjacent to each other, the boundary of the Voronoi polygon is Is defined as a part of the perpendicular bisector of the line segment connecting the point P (i) and the point P (j). The Euclidean space is as defined and described in mathematical science dictionaries.

The center of gravity of the toner particles and the center of gravity of each island in the toner particles according to the present invention are obtained by the moment of the image, and are automatically calculated by the image analysis device installed in the transmission electron microscope device. To be done. Here, the barycentric coordinates of the toner particles are obtained by calculating the product of the luminance value of the minute area at any point of the toner particles and the coordinate value of that arbitrary point. Then, for all coordinates existing in the entire toner particle, the product of the brightness and the coordinate value is obtained, and the sum of the products is calculated as the brightness of the toner particle (the total brightness value at each coordinate point obtained as described above). It is obtained by removing. Similarly, regarding the center of gravity of the island, the center of gravity of the island is also calculated by obtaining the luminance at any coordinate point in the island. As described above, the barycentric coordinates of the toner particles and the barycentric coordinates of each island existing in the toner particles according to the present invention are calculated based on the brightness at each arbitrary point, that is, from the lightness and darkness of the image.

In the present invention, the average value of the area of Voronoi polygons formed by the perpendicular bisectors between the centers of gravity of the adjacent islands in the toner particles is 20,000 nm ^{2 to} 120,000.
A toner having a size of 0 nm ² and a variation coefficient of the average value of the area of 25% or less is preferably used. Here, the variation coefficient of the area of the Voronoi polygon is calculated by the following formula.

(Calculation of variation coefficient of area of Voronoi polygon) Variation coefficient of area of Voronoi polygon = {S1 / K1} × 1
00 (%) In the formula, S1 represents the standard deviation of the area of the Voronoi polygon of the island portion existing in the toner particles, and K1 represents the average value of the area of the Voronoi polygon.

The average value of Voronoi polygons of adjacent islands in the toner particles according to the present invention is 40,000.
nm ² ~100,000nm ² are preferred, and, it is preferable that the coefficient of variation is 20% or less.

In the present invention, the average value of the Voronoi polygonal areas of adjacent islands in the toner particles is 20,000.
˜120,000 nm ² and 160,000
Toner particles having 3 to 20% by number of islands forming Voronoi polygons having an area of nm ² or more are preferably used. Further, from the viewpoint of making the charge amount distribution uniform, the number of islands forming Voronoi polygons having an area of 50,000 nm ² or less is preferably 30% by number or more of all the islands present in one toner particle, and It is preferably 60% by number or more.

The coefficient of variation of the average value of the areas of the Voronoi polygons formed by the adjacent islands in the toner particles according to the present invention specifies the variation in the area of the Voronoi polygons, that is, in the toner particles. It is intended to specify the variation of the occupied state of the island portion, and the coefficient of variation of the average value of the area of the Voronoi polygon is preferably 25% or less,
More preferably, it is 20% or less. The coefficient of variation is 0
%, That is, there is no variation in the average value of the Voronoi polygon area, in other words, there is no variation in the island occupation state in the toner particles, and all toner particles have the same island occupation state. There is no need for it.

Further, in the present invention, it is preferable that the number of islands in which the area of the Voronoi polygon is 160,000 nm ² or more is 3 to 20% of the total number of islands present in one toner particle. It means that the islands are appropriately dispersed in the particles, and such a suitable distance between the islands prevents uneven distribution of the islands in the toner particles, resulting in coloring. It is preferable that the agent is effectively added to the toner particles.

Further, in the present invention, the area of the Voronoi polygon formed by the islands existing within the specific range from the center of gravity of the toner particles is larger than the area of the Voronoi polygon formed by the islands existing outside the range. It is preferably small. That is, in the present invention, the average value of the area of the Voronoi polygon formed by the islands existing outside the radius of 1000 nm from the center of gravity of the toner particles is the average value of the area of the Voronoi polygon formed by the islands existing within the radius of 1000 nm. It is preferable that the dispersion state of the islands in the toner particles is sparse at a position apart from the center of gravity of the toner particles to some extent. By satisfying the above conditions, in the toner for developing an electrostatic image of the present invention, islands can be appropriately dispersed in the toner particles, and the effects described in the present invention can be preferably obtained. Can be done.

Further, in the toner particles having a sea-island structure, it is preferable to have a region where no island exists in the region along the outer periphery of the toner particle. Here, the region where no island exists is, for example, a region indicated by the length a and the depth b along the outer periphery of the toner particle cross section in the schematic diagrams of FIGS. 2A and 2B. .

That is, the toner of the present invention preferably has a region which does not include any island portion along the outer periphery of the toner particle cross section, and the region has a depth of 100 to 200 n.
m, more preferable depth is 120-180 nm, length is 500-6000 nm, more preferable length is 800-4.
000 nm.

As described above, by preventing the islands from existing in the specific region along the outer periphery of the toner particles, the charge retention performance is improved and the scattering of light near the surface of the toner is prevented. Presumed to be out. Furthermore, it is presumed that the effect described in the present invention is promoted by optimally dispersing the colorant added to the toner particles in the particles.

The sea part of the toner particles having the sea-island structure of the present invention contains a binder resin as a constituent component.

Further, in the toner particles having a sea-island structure, islands of other toner constituent elements may be present in addition to islands of the colorant component, but as the islands of other toner constituent elements,
An island of a crystalline substance may be mentioned, and the crystalline substance is specifically an organic compound having a melting point, preferably a hydrocarbon compound containing an ester group in its compound structure. The melting point of the crystalline substance in the toner particles according to the present invention is lower than the softening point of the toner, specifically, 130 ° C.
It is as follows. The organic compound preferably has an ester group in its structure, and also includes a crystalline polyester compound.

DSC (Differential Scanning Calorimetry) is used as a method for confirming the melting point of the crystalline substance forming the island portion, but the crystallinity is confirmed by means such as an X-ray diffractometer. Further, the crystalline substance contained in the toner of the present invention also contains a substance which exhibits a function as a release agent during image formation.

From the viewpoint of lowering the melt viscosity of the toner, improving the adhesiveness to paper, etc., maintaining the elastic modulus on the high temperature side in a preferable range even when a crystalline substance is present, and achieving good offset resistance. Therefore, the melting point of the crystalline substance is 50 ° C.
It is preferably 130 ° C, more preferably 60 ° C.
~ 120 ° C.

Here, the melting point of the crystalline substance is a value measured by DSC, and specifically, the temperature is raised from 0 ° C. to 200 ° C. under the condition of 10 ° C./min (first heating process). The temperature at which the maximum endothermic peak that is sometimes measured is the melting point. The melting point is in agreement with the “endothermic peak (P1) in the first temperature rising process by DSC” described later.

Specific examples of the melting point measuring device include DSC-7 manufactured by Perkin Elmer.
The specific method of measuring the melting point by DSC is as follows: the temperature rising / cooling conditions are 10 ° C./mi after standing at 0 ° C. for 1 minute.
The temperature is raised to 200 ° C. under the condition of n, and the temperature showing the maximum endothermic peak measured at that time is taken as the endothermic peak P1 in the first temperature raising process. Then, leave it at 200 ° C for 1 minute and then
The temperature is lowered under the condition of 0 ° C./min, and the temperature showing the maximum exothermic peak measured at that time is taken as the exothermic peak P2 in the first cooling process.

The crystalline substance used in the toner of the present invention has an endothermic peak (P1) in the first temperature rising process by DSC.
Is preferably present at 50 ° C to 130 ° C, particularly 60 ° C to 120 ° C. Further, the exothermic peak (P2) in the first cooling process by DSC is 30 ° C to 110 ° C, particularly 40 ° C to
It is preferably present at 120 ° C. Here, the endothermic peak (P1) and the exothermic peak (P2) have a relationship of P1 ≧ P2. The temperature difference (P1-P2) is not particularly limited, but is preferably 50 ° C or lower.

By including the crystalline substance having the above-mentioned thermal characteristics, it is possible to exhibit an excellent offset preventing effect (wide fixing temperature range) and an excellent fixing property (high fixing ratio). In order to exert the effect of the present invention, it is preferable that the binder resin and the crystalline substance exist in a state of being phase-separated from each other.

That is, the crystalline substance dissolves sharply, and as a result, the melt viscosity of the entire toner can be lowered, and the fixing property can be improved. Also,
By being phase-separated from each other, it is possible to suppress the decrease in elastic modulus on the high temperature side, and therefore the offset resistance is not impaired.

The shape of the toner particles according to the present invention will be described in detail. The toner particles according to the present invention have a shape coefficient variation coefficient of 16% or less, and a toner composed of toner particles having a number variation coefficient of 27% or less in a number particle size distribution. The presence of the additive becomes uniform, the charge amount distribution becomes sharp, and high fluidity is obtained. As a result, excellent developability and fine line reproducibility, and stable cleaning property can be formed for a long period of time.

Further, the inventors of the present invention conducted a study by paying attention to the minute shape of each toner particle, and as a result, inside the developing device, the shape of the corner portion of the toner particle was changed to be round and the portion was rounded. It was found that the embedding of the external additive was promoted and the change of the charge amount, the fluidity and the cleaning property were deteriorated.

When the toner particles are charged by frictional charging, it is presumed that the external additive is likely to be buried, especially at the corners, and the toner particles are likely to be unevenly charged. That is, the ratio of toner particles having no corners is set to 50 number% or more, and the number variation coefficient in the number particle size distribution is 27
By using a toner composed of toner particles controlled to be less than 100%, excellent developability and fine line reproducibility,
It has been found that a high quality image can be formed for a long period of time.

Further, it has been found that even when the toner has a specific shape and the shapes are made uniform, the external additive is not buried and the charge amount distribution becomes sharp. That is, the ratio of toner particles having a shape factor in the range of 1.01 to 1.6 is 65% by number or more, and the variation coefficient of the shape factor is 16
It has been found that even by using a toner having an amount of not more than%, it is possible to form a high-quality image having excellent developability and fine line reproducibility for a long period of time.

The number particle size distribution and number variation coefficient of the toner of the present invention will be described. The number particle size distribution and the number variation coefficient of the toner of the present invention mean Coulter counter TA
-II or Coulter Multisizer (manufactured by Coulter).

In the present invention, a Coulter multisizer was used, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting the particle size distribution and a personal computer were connected and used.

The aperture used in the Coulter multisizer is 100 μm and the aperture is 2 μm.
The particle size distribution and average particle size were calculated by measuring the volume diameter and number diameter of m or more. The number particle size distribution represents the relative frequency of toner particles to the particle size, and the number average particle size is
Cumulative 50% diameter in number particle size distribution, that is, Dn5
It represents 0.

The number variation coefficient in the number particle size distribution of toner is calculated from the following formula. Number variation coefficient = [S / Dn] × 100 (%) In the formula, S represents the standard deviation in the number particle size distribution, and Dn
Indicates the number average particle diameter (μm).

From the viewpoint of further improving the image quality, the voids of the transferred toner layer are reduced to improve the fixing property to suppress the occurrence of offset, and the charge amount distribution is sharpened to improve the transfer efficiency to further improve the image quality. The number variation coefficient of the toner is preferably 27% or less, more preferably 25% or less.

The method of controlling the number variation coefficient is not particularly limited. For example, a method of classifying toner particles by wind force can be used, but classification in a liquid is effective for reducing the number variation coefficient. Examples of the method of classifying in the liquid include a method of controlling the number of revolutions and separately collecting and adjusting the toner particles according to the difference in sedimentation speed caused by the difference in toner particle diameter.

Next, the shape factor of the toner of the present invention will be described. The toner of the present invention has a shape factor of 1.01 to
The ratio of the toner particles in the range of 1.6 to all the toner particles is 65 number% or more, and the variation coefficient of the shape coefficient is 1
It is preferably 6% or less and the number variation coefficient in the number particle size distribution is 27% or less.

The shape factor of the toner of the present invention is represented by the following formula and represents the degree of roundness of toner particles.

Shape factor = ((maximum diameter / 2) ² × π) / projected area Here, the maximum diameter is the parallel line when a projected image of toner particles on a plane is sandwiched by two parallel lines. Refers to the width of the particles at which the interval is maximum. The projected area means the area of the projected image of the toner particles on the plane. In the present invention, this shape factor is obtained by taking a photograph of the toner particles magnified 2000 times with a scanning electron microscope, and then based on the photograph, "SCANNING IMAGE ANALYZE
R ”(manufactured by JEOL Ltd.) was used to measure the photographic image. At this time, the shape factor of the present invention was measured by the above calculation formula using 100 toner particles.

Next, the toner particles without corners according to the present invention will be described. Here, the toner particles having no corners are toner particles that do not substantially have projections where electric charges are concentrated or projections that are easily worn by stress, that is, as shown in FIG. In addition, when the major axis of the toner particles T is L, a circle C having a radius (L / 10) is in contact with the peripheral line of the toner particles T at one point, and when the inside is rolled, the circle C When the toner does not substantially protrude to the outside of the toner T, it is referred to as “cornerless toner particles”. The term “when substantially not protruding” means a case where there is one or less protrusions with protruding circles.

Further, the "major axis of toner particles" means the width of particles in which the distance between the parallel lines becomes maximum when the projected image of the toner particles on the plane is sandwiched by two parallel lines. 4B and 4C are schematic diagrams showing projected images of toner particles having corners, respectively.

The toner having no corners was measured as follows. First, an enlarged photograph of toner particles is taken with a scanning electron microscope and further enlarged to obtain a photographic image at 15,000 times magnification. Then, the presence or absence of the above-mentioned corner is measured for this photographic image. This measurement was performed on 1000 toner particles.

The generation of fine particles due to the stress with the developer transport member is reduced to suppress the contamination on the surface of the developer transport member, the charge amount distribution is sharpened, the chargeability is stabilized, and a better image quality is obtained. From the viewpoint of forming the toner particles for a long time, the ratio of the toner particles having no corners to all the toner particles is preferably 50% by number or more, and more preferably 70% by number or more.

The method for obtaining the toner without corners is not particularly limited. For example, as described above as a method of controlling the shape factor, a method of spraying toner particles in a hot air flow, a method of repeatedly applying mechanical energy due to impact force in a gas phase, or a method of dissolving toner It can be obtained by adding it to a solvent that does not contain it and imparting a swirling flow.

In the toner of the present invention, when the particle diameter of the toner particles is D (μm), the natural logarithm lnD is plotted on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23. In the histogram showing the standard particle size distribution, the sum of the relative frequency (m1) of toner particles included in the most frequent class and the relative frequency (m2) of toner particles included in the next most frequent class. It is preferable that the toner (M) is 70% or more.

When the sum (M) of the relative frequency (m1) and the relative frequency (m2) is 70% or more, the dispersion of the particle size distribution of the toner particles becomes narrow, so that the toner is used in the image forming process. As a result, the occurrence of selective development can be reliably suppressed.

In the present invention, the histogram showing the number-based particle size distribution has a natural logarithm lnD (D: particle size of each toner particle) in a plurality of classes (0 to 0) at intervals of 0.23.
0.23: 0.23 to 0.46: 0.46 to 0.69:
0.69 to 0.92: 0.92 to 1.15: 1.15
1.38: 1.38 to 1.61: 1.61 to 1.84:
1.84-2.07: 2.07-2.30: 2.30-
2.53: 2.53 to 2.76 ...), which is a histogram showing the number-based particle size distribution, and this histogram is the particle size data of the sample measured by the Coulter Multisizer according to the following conditions. Was transferred to the computer via the I / O unit, and was created by the particle size distribution analysis program in the computer.

[Measurement conditions] 1: Aperture: 100 μm 2: Sample preparation method: Electrolyte solution [ISOTON II (manufactured by Coulter Scientific Japan)] 50 ml
An appropriate amount of a surfactant (neutral detergent) is added to 100 ml and stirred, and 10 mg to 20 mg of a measurement sample is added thereto. This system is prepared by subjecting it to an ultrasonic disperser for 1 minute.

The particle size of the toner particles according to the present invention will be described. The toner particles according to the present invention have a number average particle diameter of preferably 3 μm to 9 μm, more preferably 4.5 μm to 8.5 μm, and particularly preferably 5 μm to 8 μm.

The particle size of the toner particles depends on the concentration of the aggregating agent (salting out agent), the amount of the organic solvent added, the
It can be controlled by the fusion time and the composition of the polymer.

When the number average particle diameter is 3 to 9 μm, the transfer efficiency is improved, the halftone image quality is improved, and the image quality of fine lines and dots is improved. To calculate the particle size distribution of toner and measure the number average particle size, use Coulter Counter TA-
II, Coulter Multisizer (both manufactured by Coulter, Inc.), SLAD1100 (laser diffraction particle size measuring device manufactured by Shimadzu Corporation), and the like can be used for measurement. In the present invention, a Coulter multisizer was used, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting the particle size distribution and a personal computer were connected and measured and calculated.

Next, the method for producing the toner of the present invention will be described. The toner of the present invention is obtained by polymerizing at least a polymerizable monomer in an aqueous medium, and this production method is to prepare resin particles by polymerizing the polymerizable monomer by a suspension polymerization method. Alternatively, emulsion polymerization or miniemulsion polymerization of the monomer is performed in a liquid (in an aqueous medium) containing an emulsion of the necessary additives to prepare fine resin particles, and charge as necessary. After the controllable resin particles are added, an organic solvent, an aggregating agent such as salts, and the like are added to coagulate and fuse the resin particles.

<Suspension Polymerization Method> As an example of the method for producing the toner of the present invention, a charge control resin is dissolved in a polymerizable monomer, and a colorant and, if necessary, a release agent, and further polymerization are used. Various constituent materials such as an initiator are added, and the various constituent materials are dissolved or dispersed in the polymerizable monomer using a homogenizer, a sand mill, a sand grinder, an ultrasonic disperser or the like.
The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in an oil droplet having a desired size as a toner in a water-based medium containing a dispersion stabilizer by using a homomixer or a homogenizer. After that, the stirring mechanism is moved to a reaction device (stirring device) which is a stirring blade described later, and the polymerization reaction is advanced by heating. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare the toner of the present invention. The “aqueous medium” as referred to in the present invention means one containing at least 50% by mass of water.

<Emulsion Polymerization Method> As another method for producing the toner of the present invention, a method of salting out / fusing resin particles in an aqueous medium to prepare may be mentioned. This method is not particularly limited, but for example, JP-A-5-265252 and JP-A-6-32994.
No. 7, JP-A-9-15904 can be mentioned. That is, a method in which resin particles and dispersed particles of constituent materials such as a coloring agent, or a plurality of fine particles composed of a resin and a coloring agent are salted out, aggregated, and fused, particularly, these are dispersed in water using an emulsifier. After that, a coagulant having a critical coagulation concentration or more is added for salting out, and at the same time, the particles are gradually grown while forming fused particles by heat fusion at a temperature not lower than the glass transition temperature of the formed polymer itself. When the desired particle size is reached, a large amount of water is added to stop the particle size growth, and the particle surface is smoothed while heating and stirring to control the shape, and the particles are heated in a fluid state while containing water. By drying, the toner of the present invention can be formed. Here, a solvent such as alcohol, which is infinitely soluble in water, may be added together with the coagulant.

In the method for producing a toner of the present invention, the composite resin fine particles formed through the step of polymerizing the polymerizable monomer after the crystalline substance is dissolved in the polymerizable monomer and the colorant particles are salted. The method of depositing / fusing is preferably used.
When the crystalline substance is dissolved in the polymerizable monomer, the crystalline substance may be dissolved and then melted, or may be melted and dissolved.

As the method for producing the toner of the present invention, a step of salting out / fusing the composite resin fine particles obtained by the multi-stage polymerization method and the colorant particles is preferably used. Here, the multistage polymerization method will be described below.

(Manufacturing Method of Composite Resin Particles Obtained by Multistep Polymerization Method) When the multistep polymerization method is used, the toner manufacturing method of the present invention preferably comprises the following steps.

1: multi-stage polymerization step 2: salting out / fusing composite resin particles and colorant particles to obtain toner particles Salting out / fusing step 3: filtering the toner particles from a dispersion system of toner particles Then
A filtration / washing step for removing a surfactant and the like from the toner particles, a drying step for drying the washed toner particles, and a step for adding an external additive to the dried toner particles.

Each step will be described in detail below. [Multistage Polymerization Step] The multistage polymerization step is a polymerization method carried out in order to expand the molecular weight distribution of the resin particles in order to obtain a toner in which offset generation is prevented. That is, the polymerization reaction is performed in multiple stages in order to form a phase having different molecular weight distributions in one resin particle, and the obtained resin particle has a molecular weight gradient from the center of the particle toward the surface layer. It is intended to be formed. For example, a method of forming a low molecular weight surface layer by first adding a polymerizable monomer and a chain transfer agent after obtaining a high molecular weight resin particle dispersion liquid is adopted.

In the present invention, it is preferable to employ a multi-step polymerization method of three or more steps from the viewpoint of stability of production and crushing strength of the obtained toner. The two-step polymerization method and the three-step polymerization method, which are typical examples of the multi-step polymerization method, will be described below. In the toner obtained by such a multi-step polymerization reaction, a toner having a lower molecular weight on the surface layer is preferable from the viewpoint of crushing strength.

<Two-Step Polymerization Method> The two-step polymerization method is a central part (nucleus) formed from a high molecular weight resin containing a crystalline substance.
And a method for producing composite resin particles composed of an outer layer (shell) formed of a low molecular weight resin.

To explain this method in detail, first, a crystalline substance is dissolved in a monomer to prepare a monomer solution, and this monomer solution is added to an aqueous medium (for example, an aqueous solution of a surfactant).
After dispersing oil droplets therein, the system is subjected to a polymerization treatment (first stage polymerization) to prepare a dispersion liquid of high molecular weight resin particles containing a crystalline substance.

Then, a polymerization initiator and a monomer for obtaining a low molecular weight resin are added to the dispersion liquid of the resin particles, and the monomer is subjected to a polymerization treatment in the presence of the resin particles (second-stage polymerization). Is a method of forming a coating layer made of a low molecular weight resin (polymer of monomer) on the surface of the resin particles.

<Three-Step Polymerization Method> The three-step polymerization method comprises a central portion (nucleus) formed of a high molecular weight resin, an intermediate layer containing a crystalline substance, and an outer layer (shell) formed of a low molecular weight resin. It is a method for producing composite resin particles. The toner of the present invention exists as the composite resin particles as described above.

This method will be described in detail. First, a dispersion liquid of resin particles obtained by a polymerization treatment (first-stage polymerization) according to a conventional method is added to an aqueous medium (for example, an aqueous solution of a surfactant). Along with the addition of the above, in the above aqueous medium, a monomer solution obtained by dissolving a crystalline substance in a monomer is dispersed in oil droplets, and then this system is subjected to a polymerization treatment (second-stage polymerization) to obtain a resin. A coating layer (intermediate layer) made of a resin (monomer polymer) containing a crystalline substance is formed on the surface of the particles (core particles) to form a composite resin particle (high molecular weight resin-intermediate molecular weight resin). Prepare the dispersion.

Next, a polymerization initiator and a monomer for obtaining a low molecular weight resin are added to the obtained dispersion liquid of the composite resin particles, and the monomer is subjected to a polymerization treatment in the presence of the composite resin particles ( By three-step polymerization), a coating layer made of a low molecular weight resin (polymer of monomer) is formed on the surface of the composite resin particles. In the above method, by incorporating an intermediate layer, the crystalline substance can be dispersed finely and uniformly, which is preferable.

One feature of one embodiment of the method for producing a toner of the present invention is that the polymerizable monomer is polymerized in an aqueous medium. That is, when forming the resin particles (nuclear particles) or the coating layer (intermediate layer) containing the crystalline substance,
It is a method of obtaining latex particles by dissolving a crystalline substance in a monomer, dispersing the resulting monomer solution in oil droplets in an aqueous medium, and adding a polymerization initiator to this system for polymerization. .

The aqueous medium as used in the present invention means water 50 to 10
A medium composed of 0 mass% and a water-soluble organic solvent of 0 to 50 mass%. As the water-soluble organic solvent, for example, methanol, ethanol, isopropanol, butanol,
Acetone, methyl ethyl ketone, tetrahydrofuran and the like can be exemplified, and an alcohol-based organic solvent that does not dissolve the obtained resin is preferable.

As a suitable polymerization method for forming resin particles or a coating layer containing a crystalline substance, the crystalline substance is dissolved in an aqueous medium in which a surfactant having a concentration below the critical micelle concentration is dissolved. A monomer solution dissolved in a monomer is dispersed into oil droplets using mechanical energy to prepare a dispersion liquid, and a water-soluble polymerization initiator is added to the obtained dispersion liquid to A method of radical polymerization (hereinafter referred to as "mini-emulsion method" in the present invention) can be mentioned, and the effects of the present invention can be exhibited more preferably. In addition,
In the above method, an oil-soluble polymerization initiator may be used instead of the water-soluble polymerization initiator or together with the water-soluble polymerization initiator.

According to the mini-emulsion method of mechanically forming oil droplets, unlike the usual emulsion polymerization method, the crystalline substance dissolved in the oil phase is less desorbed and the resin particles or the coating layer to be formed are formed. A sufficient amount of crystalline substance can be introduced therein.

Here, the disperser for dispersing the oil droplets by mechanical energy is not particularly limited, and for example, a stirrer "CLEARMIX" (M -Technique Co., Ltd.), an ultrasonic disperser, a mechanical homogenizer, a Manton Gaulin, a pressure homogenizer, and the like. The dispersed particle size is 1
0 nm to 1000 nm is preferable, and 50 is more preferable.
nm to 1000 nm, particularly preferably 30 nm
~ 300 nm.

By giving a distribution to the dispersed particle diameter, the phase separation structure of the crystalline substance in the toner particles, that is, the Feret horizontal diameter, the shape coefficient and the variation coefficient thereof may be controlled.

As the other polymerization method for forming the resin particles containing the crystalline substance or the coating layer, known methods such as emulsion polymerization method, suspension polymerization method and seed polymerization method can be adopted. . In addition, these polymerization methods can also be adopted to obtain resin particles (core particles) or a coating layer forming the composite resin particles, which does not contain a crystalline substance.

The particle size of the composite resin particles obtained in this polymerization step is 10 to 10 in terms of the mass average particle size measured by using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).
It is preferably in the range of 1000 nm.

Further, the glass transition temperature (T
g) is preferably in the range of 48 ° C to 74 ° C, more preferably 52 ° C to 64 ° C.

The softening point of the composite resin particles is 95 ° C to 1
A range of 40 ° C is preferred. The toner of the present invention is obtained by fusing resin particles to the surface of resin and colored particles by a salting out / fusing method to form a resin layer,
This will be described below.

[Salting-out / fusion-bonding step] In this salting-out / fusion-bonding step, the composite resin particles obtained by the multi-step polymerization step and the colorant particles are salted-out / fusion-bonded (salting-out and fusion-bonding). Is caused at the same time) to obtain amorphous (non-spherical) toner particles.

In the present invention, salting out / fusing means that salting out (aggregation of particles) and fusing (disappearance of interface between particles) occur at the same time, or salting out and fusing at the same time. Refers to an act. In order to perform salting out and fusion at the same time,
Glass transition temperature (Tg) of resin constituting composite resin particles
It is preferable to aggregate the particles (composite resin particles, colorant particles) under the above temperature conditions.

In this salting out / fusing step, internal additive particles (fine particles having a number average primary particle diameter of about 10 nm to 1000 nm) such as a charge control agent are salted out / fused together with the composite resin particles and the colorant particles. You may let me. Further, the colorant particles may be surface-modified, and as the surface-modifying agent,
Conventionally known ones can be used.

[Aging Step] The aging step is a step subsequent to the salting-out / fusion step, and the temperature is kept near the melting point of the crystalline substance, preferably the melting point ± 20 ° C. after the resin particles are fused, and the temperature is kept constant. In this step, the crystalline substance is phase-separated by continuing stirring at the intensity of 1. In this step, it is possible to control the ferret horizontal diameter of the crystalline substance, the shape factor and the variation coefficients thereof.

In the present invention, the total value of the divalent (trivalent) metal element used as the aggregating agent and the monovalent metal element added as an aggregating terminator described later is 350 to 35,000 pp.
It is preferably m. X-ray fluorescence analyzer "System 3270" is used to measure the amount of residual metal ions in the toner.
It can be determined by measuring the intensity of fluorescent X-ray emitted from the metal species of the metal salt used as the aggregating agent (for example, calcium derived from calcium chloride) using [Rigaku Denki Kogyo KK]. As a specific measuring method, a plurality of toners having a known content ratio of the aggregating agent metal salt are prepared, 5 g of each toner is pelletized, the content ratio (mass ppm) of the aggregating agent metal salt, and the metal species of the metal salt. The relationship (calibration curve) with the fluorescent X-ray intensity (peak intensity) from is measured. Next, the toner (sample) whose content ratio of the aggregating agent metal salt is to be measured is pelletized in the same manner, and the fluorescent X-ray intensity from the metal species of the aggregating agent metal salt is measured to determine the content ratio, that is, "metal ion remaining in the toner You can ask for the "quantity".

[Filtration / Washing Step] In this filtration / washing step, a filtering treatment for filtering the toner particles from the dispersion system of the toner particles obtained in the above step and the filtered toner particles (cake-shaped A cleaning process is performed to remove deposits such as surfactants and salting-out agents from the aggregate. Here, the filtration method is not particularly limited, such as a centrifugal separation method, a vacuum filtration method using a Nutsche or the like, or a filtration method using a filter press or the like.

[Drying Step] In this step, the washed toner particles are dried.

Examples of the dryer used in this step include a spray dryer, a vacuum freeze dryer, a vacuum dryer and the like. A stationary shelf dryer, a mobile shelf dryer, a fluidized bed dryer, a rotary dryer It is preferable to use a dryer or a stirring dryer.

The water content of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less.

The toner particles that have been dried are
When the aggregates are aggregated by the weak attraction between particles, the aggregates may be crushed. Here, as the disintegration processing device,
A mechanical crushing device such as a jet mill, a Henschel mixer, a coffee mill or a food processor can be used.

The toner of the present invention forms composite resin particles in the absence of a colorant, adds the dispersion of the colorant particles to the dispersion of the composite resin particles, and mixes the composite resin particles with the colorant particles. It is preferably prepared by salting out / fusing.

Thus, by carrying out the preparation of the composite resin particles in the system in which no colorant is present, the polymerization reaction for obtaining the composite resin particles is not hindered. Therefore, according to the toner of the present invention, the excellent offset resistance is not impaired, and the contamination of the fixing device and the image stain due to the accumulation of the toner do not occur.

Further, as a result of the polymerization reaction being surely carried out to obtain the composite resin particles, no monomer or oligomer remains in the obtained toner particles, and the image forming method using the toner concerned No offensive odor is generated in the heat fixing step.

Further, the obtained toner particles have uniform surface characteristics and a sharp charge amount distribution, so that an image having excellent sharpness can be formed for a long period of time. Such a toner having a uniform composition, molecular weight, and surface characteristics among toner particles maintains good adhesiveness (high fixing strength) to an image support in an image forming method including a fixing step by a contact heating method. However, it is possible to improve the offset resistance and the wrapping prevention property, and an image having an appropriate gloss can be obtained.

Further, as the fixing improving agent according to the present invention,
A crystalline compound having an ester group is preferably used. Specific examples thereof include higher fatty acid esters, natural waxes such as carnauba wax and rice wax, and crystalline polyester.

Among the compounds having an ester group, the ester compounds represented by the following general formula are particularly preferably used.

In the general formula R _1- (OCO-R ₂ ) _n , n represents an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, and most preferably 4.

R ₁ and R ₂ represent a hydrocarbon group which may have a substituent. R _1: a carbon number = 1-40, preferably 1-20, more preferably 2 to 5 R _2: the number of carbon atoms = 1-40, preferably 13-29, more preferably to 12 to 25 below, the present invention Specific examples of the crystalline compound having such an ester group are shown below, but the present invention is not limited thereto.

[0210]

[Chemical 3]

[0211]

[Chemical 4]

The crystalline compound having an ester group according to the present invention is contained in the resin particles and has a function of imparting good fixability (adhesiveness to the image support) to the toner obtained by fusing the resin particles. Have.

The melting point of the crystalline compound is 60 to
It is preferably in the range of 110 ° C, and more preferably in the range of 70 to 90 ° C.

By using a crystalline compound having an ester group having a melting point in the range of 60 to 110 ° C., it is possible to lower the melt viscosity of the entire toner and to improve the adhesiveness to paper or the like. Moreover, even if the crystalline compound is present, the elastic modulus on the high temperature side is maintained in a preferable range, so that good offset resistance can be obtained.

Here, the melting point of the crystalline compound means a value measured by a differential calorimeter (DSC). Specifically, the temperature showing the maximum endothermic peak measured when the temperature is raised from 0 ° C. to 200 ° C. under the condition of 10 ° C./min (first heating process) is defined as the melting point. Then, this melting point coincides with the above-mentioned "toner endothermic peak in differential thermal analysis".

The number average molecular weight of the crystalline polyester according to the present invention is preferably 1,500 to 15,000, more preferably 2,000 to 10,000.

According to the crystalline polyester having a number average molecular weight in the range of 1,500 to 15,000, a binder resin (amorphous polymer) for exerting a decrease in the overall melt viscosity in the obtained toner. The compatibility in the molten state with and is improved, and the fixability on the lower temperature side is improved.

Here, the number average molecular weight of the crystalline polyester means a value obtained from the molecular weight measured according to the following conditions.

(Conditions) -Model used: "LC-6A" (manufactured by Shimadzu Corporation) -Column: "Ultrastyla Gel Plus" -Analysis temperature: 60 ° C-Solvent: m-cresol / chlorobenzene = 3/1
(Volume ratio) Calibration curve: Standard polystyrene calibration curve When a crystalline polyester is used as a crystalline compound having an ester group, its melt viscosity (melting point + melting point +
The melt viscosity at 20 ° C.) is preferably 300 dPa · s or less, more preferably 250 dPa · s or less.

According to the crystalline polyester having a melt viscosity of 300 dPa · s or less, in the obtained toner,
It becomes possible to reduce the melt viscosity of the whole including the binder resin, and the fixability is improved.

The melt viscosity of the crystalline polyester (melting point + melt viscosity at 20 ° C.) is a value measured by a cone plate viscometer.

The peak molecular weight of the crystalline polyester measured by GPC is preferably in the range of 6,000 to 50,000. As the crystalline polyester, the endothermic peak (P1) in the first temperature rising process by DSC is 60 to 120 ° C.
What exists in the range of is preferable.

The binder resin according to the present invention will be described.
As the polymerizable monomer for producing the binder resin according to the present invention, a hydrophobic monomer is used as an essential constituent component, and a crosslinkable monomer is used if necessary. Further, it is desirable to contain at least one kind of monomer having an acidic polar group or basic polar group in the structure as described below.

(1) Hydrophobic Monomer The hydrophobic monomer constituting the monomer component is not particularly limited, and conventionally known monomers can be used. Further, one kind or a combination of two or more kinds can be used so as to satisfy the required characteristics.

Specifically, a monovinyl aromatic monomer,
(Meth) acrylic acid ester-based monomer, vinyl ester-based monomer, vinyl ether-based monomer, monoolefin-based monomer, diolefin-based monomer, halogenated olefin-based monomer, etc. may be used. it can.

Examples of vinyl aromatic monomers include, for example:
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- Examples thereof include styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

Examples of the (meth) acrylic acid ester type monomer include acrylic acid, methacrylic acid, methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
-Ethylhexyl, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, γ-aminopropyl acrylate, methacrylic acid Stearyl, dimethylaminoethyl methacrylate,
Diethylaminoethyl methacrylate and the like can be mentioned.

Examples of the vinyl ester-based monomer include vinyl acetate, vinyl propionate, vinyl benzoate, etc., and examples of the vinyl ether-based monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether. Etc.

Further, as the monoolefin type monomer, ethylene, propylene, isobutylene, 1-butene, 1-
Examples thereof include pentene and 4-methyl-1-pentene, and examples of the diolefin-based monomer include butadiene, isoprene and chloroprene.

(2) Crosslinkable Monomer A crosslinkable monomer may be added to improve the properties of the resin particles. Examples of the crosslinkable monomer include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate and diallyl phthalate.

(3) Monomer having acidic polar group As the monomer having an acidic polar group, (a) an α, β-ethylenically unsaturated compound having a carboxyl group (—COOH), and (b) ) Examples thereof include α, β-ethylenically unsaturated compounds having a sulfone group (—SO ₃ H).

Α, β-having a carboxyl group (a)
Examples of ethylenically unsaturated compounds include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid,
Examples thereof include cinnamic acid, maleic acid monobutyl ester, maleic acid monooctyl ester, and metal salts thereof such as Na and Zn.

Examples of the α, β-ethylenically unsaturated compound having a sulfone group (b) include sulfonated styrene and its Na salt, allylsulfosuccinic acid, octyl allylsulfosuccinate, and their Na salts. Can be mentioned.

(4) Monomer having a basic polar group As the monomer having a basic polar group, (a) an amine group or a quaternary ammonium group having 1 to 1 carbon atoms is used.
2, preferably 2 to 8, particularly preferably 2 (meth) acrylic acid ester of an aliphatic alcohol, (b) (meth)
Acrylic amide or optionally 1 to 1 carbon atoms on N
(Meth) acrylic acid amide mono- or di-substituted with 18 alkyl groups, (c) vinyl compound substituted with a heterocyclic group having N as a ring member, and (d) N, N-diallyl-alkylamine or a compound thereof. A quaternary ammonium salt can be illustrated. Among them, (meth) of aliphatic alcohol having an amine group or a quaternary ammonium group of (a)
Acrylic acid esters are preferred as the monomer having a basic polar group.

Examples of the (meth) acrylic acid ester of an aliphatic alcohol having an amine group or a quaternary ammonium group of (a) include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and the above. Quaternary ammonium salt of 4 compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy-
3-methacryloxypropyl trimethyl ammonium salt etc. can be mentioned.

Examples of the (meth) acrylic acid amide (b) or the (meth) acrylic acid amide optionally substituted with mono- or dialkyl on N include acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, Methacrylamide, N-butylmethacrylamide, N, N-dimethylacrylamide,
N-octadecyl acrylamide etc. can be mentioned.

Examples of the vinyl compound (c) substituted with a heterocyclic group having N as a ring member include vinylpyridine, vinylpyrrolidone, vinyl-N-methylpyridinium chloride, vinyl-N-ethylpyridinium chloride and the like. You can

Examples of (d) N, N-diallyl-alkylamine include N, N-diallylmethylammonium chloride, N, N-diallylethylammonium chloride and the like.

(Polymerization Initiator) The radical polymerization initiator used in the present invention can be appropriately used if it is water-soluble. For example, persulfates (eg, potassium persulfate, ammonium persulfate, etc.), azo compounds (eg, 4,4 ′)
-Azobis-4-cyanovaleric acid and its salts, 2,2'-azobis (2-amidinopropane) salt, etc.), peroxide compounds and the like. Further, the above radical polymerization initiator can be combined with a reducing agent as required to form a redox initiator. By using the redox type initiator, the polymerization activity can be increased, the polymerization temperature can be lowered, and further the polymerization time can be shortened, which is a preferable aspect.

The polymerization temperature is not particularly limited as long as it is at least the minimum radical generation temperature of the polymerization initiator, but is, for example, in the range of 50 ° C to 90 ° C. However, it is also possible to carry out the polymerization at room temperature or higher by using a room temperature-initiated polymerization initiator in which a hydrogen peroxide-reducing agent (ascorbic acid or the like) is combined.

(Chain transfer agent) A known chain transfer agent can be used for the purpose of adjusting the molecular weight. The chain transfer agent is not particularly limited, for example, octyl mercaptan, dodecyl mercaptan,
A compound having a mercapto group such as tert-dodecyl mercaptan is used. In particular, a compound having a mercapto group is preferably used because it suppresses an odor at the time of heating and fixing, a toner having a sharp molecular weight distribution is obtained, and it has excellent storage stability, fixing strength, and offset resistance. Preferred are, for example, ethyl thioglycolate,
The mercapto group of propyl thioglycolate, propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, ethylene glycol is used. Examples thereof include compounds having a mercapto group of neopentyl glycol, and compounds having a mercapto group of pentaerythritol. Of these, from the viewpoint of suppressing odor during toner heat fixing, n-octyl-
Particularly preferred is 3-mercaptopropionic acid ester.

(Surfactant) In order to carry out miniemulsion polymerization using the above-mentioned polymerizable monomer, it is preferable to use a surfactant to disperse oil droplets in an aqueous medium. The surfactant that can be used in this case is not particularly limited, but the following ionic surfactants can be mentioned as examples of suitable compounds.

Examples of the ionic surfactant include sulfonates (sodium dodecylbenzene sulfonate,
Aryl alkyl polyether sodium sulfonate,
3,3-disulfone diphenylurea-4,4-diazo-
Sodium bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol -6-
Sodium sulfonate, etc.), sulfate ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.),
Examples thereof include fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, etc.).

In the present invention, the following general formula (1)
The surfactant (2) is particularly preferably used.

General formula (a) R ¹ (OR ² ) _n OSO ₃ M General formula (b) R ¹ (OR ² ) _n SO ₃ M In general formulas (a) and (b), R ¹ has 6 carbon atoms. ~ 22
Is preferably an alkyl group or an arylalkyl group having 8 to 20 carbon atoms, and more preferably an alkyl group or an arylalkyl group having 9 to 16 carbon atoms.

Examples of the alkyl group having 6 to 22 carbon atoms represented by R ¹ include n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, n-undecyl group and n-hexadecyl group. Group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like, and the arylalkyl group represented by R ¹ includes benzyl group, diphenylmethyl group, cinnamyl group, styryl group, trityl group, phenethyl group and the like. .

In the general formulas (a) and (b), R ² represents an alkylene group having 2 to 6 carbon atoms, preferably an alkylene group having 2 to 3 carbon atoms. ² carbon atoms represented by R 2
Examples of the alkylene group of to 6 include ethylene group, trimethylene group, tetramethylene group, propylene group and ethylethylene group.

In the general formulas (a) and (b), n is 1 to
Although it is an integer of 11, it is preferably 2 to 10, more preferably 2 to 5, and particularly preferably 2 to 3.

In the general formulas (1) and (2), the monovalent metal element represented by M includes sodium, potassium and lithium. Among them, sodium is preferably used.

Specific examples of the surfactants represented by the general formulas (a) and (b) are shown below, but the invention is not limited thereto.

Compound (101): C ₁₀ H ₂₁ (OCH ₂ C
H _{2) 2} OSO ₃ Na Compound _{(102): C 10 H 21} (OCH 2 CH 2) 3 OSO 3
Na compound _{(103): C 10 H 21} (OCH 2 CH 2) 2 SO 3 N
a Compound (104): C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₃ SO ₃ N
a Compound (105): C ₈ H ₁₇ (OCH ₂ CH (CH ₃ )) ₂
OSO ₃ Na compound (106): C ₁₈ H ₃₇ (OCH ₂ CH ₂ ) ₂ OSO ₃
In the present invention, from the viewpoint of keeping the charge retention function of the toner in a good state, suppressing fog generation under high temperature and high humidity, and improving transferability, and suppressing increase in charge amount under low temperature and low humidity, From the viewpoint of stabilizing the development amount, the content of the surfactant represented by the general formulas (a) and (b) in the toner for developing an electrostatic image is preferably 1 to 1000 ppm, more preferably It is 5 to 500 ppm, and particularly preferably 7 to 100 ppm.

In the present invention, by setting the amount of the surfactant contained in the toner within the above-mentioned range, the electrostatic property of the toner for developing an electrostatic charge image of the present invention is not influenced by the influence of the environment and is always It is possible to be applied and maintained in a uniform and stable state.

The content of the surfactant represented by the above general formulas (a) and (b) contained in the toner for developing an electrostatic image of the present invention is calculated by the following method. .

1 g of the toner is dissolved in 50 ml of chloroform, and the surfactant is extracted from the chloroform layer with 100 ml of ion-exchanged water. The extracted chloroform layer was extracted again with 100 ml of ion-exchanged water to obtain a total of 200 ml of extract liquid (water layer).
Dilute to 00 ml.

Using this diluted solution as a test solution, JIS 33
According to the method defined in Item 636, the color is developed with methylene blue, the absorbance is measured, and the content of the surfactant in the toner is measured from a separately prepared calibration curve.

The boundaries represented by the general formulas (a) and (b) are
The structure of the surfactant is ¹Using H-NMR
Then, the structure was determined.

In the present invention, a metal salt can be preferably used as an aggregating agent in the step of salting out, aggregating and fusing resin particles from a dispersion liquid of resin particles prepared in an aqueous medium. It is further preferable to use a trivalent metal salt as the aggregating agent. The reason is that a divalent or trivalent metal salt is preferable to a monovalent metal salt because the critical aggregation concentration (coagulation value or coagulation point) is smaller.

In the present invention, a nonionic surfactant may be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, an ester of polyethylene glycol and higher fatty acid, an alkylphenol. Examples thereof include polyethylene oxide, higher fatty acid and polyethylene glycol ester, higher fatty acid and polypropylene oxide ester, and sorbitan ester.

In the present invention, these surfactants are mainly used as an emulsifier during emulsion polymerization, but may be used for other steps or for other purposes.

(Molecular Weight Distribution of Resin Particles and Toner) The toner of the present invention has a peak or shoulder of 10 in the molecular weight distribution.
20,000 to 1,000,000, and 1,000 to 5
It is preferable that the peak or shoulder of the molecular weight distribution is 100,000 to 1,000,000.
0, 25,000-150,000 and 1,000-5
It is preferably present at 10,000.

The molecular weight of the resin particles is 100,000 to
A resin containing at least a high molecular weight component having a peak or shoulder in the region of 1,000,000 and a low molecular weight component having a peak or shoulder in the region of 1,000 to less than 50,000 is preferable, and more preferably Is
It is preferable to use an intermediate molecular weight resin having a peak or shoulder in the portion of 15,000 to 100,000.

The above-mentioned method for measuring the molecular weight of the toner or resin is carried out according to GP using THF (tetrahydrofuran) as a solvent.
Measurement by C (gel permeation chromatography) is preferable. That is, 1.0 ml of THF is added to 0.5 to 5 mg of the measurement sample, more specifically 1 mg, and stirred at room temperature using a magnetic stirrer or the like to sufficiently dissolve the sample. Next, pore size 0.45
After treatment with a 0.50 μm membrane filter,
Inject into GPC. The GPC measurement conditions are as follows: the column is stabilized at 40 ° C., THF is allowed to flow at a flow rate of 1.0 ml / min, and a sample having a concentration of 1 mg / ml is injected in an amount of about 100 μl. The column is preferably used in combination with a commercially available polystyrene gel column. For example, Shodex GPC KF-801, 80 manufactured by Showa Denko KK
2, 803, 804, 805, 806, 807 combination and TSKgel G1000H, G200 manufactured by Tosoh Corporation
0H, G3000H, G4000H, G5000H, G
6000H, G7000H, TSK guard co
Examples include a combination of lumn. As a detector, a refractive index detector (IR detector) or U
A V detector may be used. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve prepared using monodisperse polystyrene standard particles. About 10 points may be used as polystyrene for preparing the calibration curve.

(Aggregating agent) In the present invention, a metal salt can be preferably used as an aggregating agent in the steps of salting out, aggregating and fusing resin particles from a dispersion liquid of resin particles prepared in an aqueous medium. It is further preferable to use a divalent or trivalent metal salt as the aggregating agent. The reason is that a divalent or trivalent metal salt is preferable to a monovalent metal salt because the critical aggregation concentration (coagulation value or coagulation point) is smaller.

The aggregating agent used in the present invention is, for example, a monovalent metal salt which is a salt of an alkali metal such as sodium, potassium and lithium, for example, a salt of an alkaline earth metal such as calcium and magnesium and manganese and copper. Examples thereof include divalent metal salts and trivalent metal salts such as iron and aluminum.

Specific examples of these metal salts are shown below.
Examples of the monovalent metal salt include sodium chloride, potassium chloride, lithium chloride, and examples of the divalent metal salt include calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and the like. Examples include aluminum chloride and iron chloride. These are appropriately selected according to the purpose, but divalent or trivalent metal salts having a small critical aggregation concentration are preferable.

The critical coagulation concentration referred to in the present invention is an index relating to the stability of the dispersion in the aqueous dispersion, and shows the addition concentration of the coagulation agent when the coagulation agent is added and coagulation occurs. This critical coagulation concentration greatly changes depending on the latex itself and the dispersant. For example, it is described in Seizo Okamura et al., Polymer Chemistry 17,601 (1960),
The value can be known by following these descriptions.
Further, as another method, a desired salt is added to the target particle dispersion liquid while changing the concentration, and the ζ potential of the dispersion liquid is measured,
It is also possible to set the salt concentration at the point where the ζ potential changes as the critical aggregation concentration.

In the present invention, the polymer fine particle dispersion is treated with a metal salt so as to have a concentration higher than the critical aggregation concentration. At this time, of course, directly add the metal salt,
Whether to add as an aqueous solution is arbitrarily selected according to the purpose. When it is added as an aqueous solution, the added metal salt needs to have a critical coagulation concentration of the polymer particles or more with respect to the volume of the polymer particle dispersion and the total volume of the metal salt aqueous solution.

In the present invention, the concentration of the metal salt may be equal to or higher than the critical coagulation concentration, but is preferably 1.
The amount is 2 times or more, more preferably 1.5 times or more.

The image forming method of the present invention will be described.
In the present invention, in an image forming method having a step of visualizing an electrostatic latent image formed on a photoconductor, transferring the visible image onto a recording medium, and heating and fixing the image, the heating and fixing are performed in an endless belt form. The fixing is preferably carried out by a fixing device having a film or a fixing device using an end film. Here, the toner for developing an electrostatic image of the present invention is used for the above-mentioned visualization.

As an example of a fixing device having an endless belt-like film used for heat fixing, for example, a fixing method using a rotating pressure member containing a fixedly arranged heating element is preferably used.

This fixing system is a system in which a heating member fixedly arranged and a pressurizing member that is in pressure contact with the heating member and is in close contact with the heating member to bring the transfer material into close contact with the heating member are heated and fixed by pressure.

In this pressure contact heat fixing device, the heating body has a smaller heat capacity than the conventional heating roller, and has a linear heating portion in the direction perpendicular to the passing direction of the transfer material. Is preferably adjusted in the range of 100 ° C to 300 ° C.

The pressure contact heat fixing is performed by pressing an unfixed toner image against a heating source, such as a system of passing a transfer material containing unfixed toner between a heating member and a pressure member. Is the way. Due to such measures, the heating is performed quickly, so that the fixing speed can be increased, but it is difficult to control the temperature, and the toner adheres to and remains on the portion where the unfixed toner is directly pressed against the heating source surface portion, etc. There is also a problem that so-called toner offset is likely to occur, and a failure such as the transfer material being wound around the fixing device is likely to occur.

In this fixing system, the low-heat-capacity linear heating element fixedly supported by the apparatus has a thickness of 0.2 mm to
5.0 mm, more preferably 0.5 mm to 3.5 mm
Width of 10 mm to 15 mm, longitudinal length of 240 mm to 400 m
Resistance material 1.0mm-2.5mm on m alumina substrate
It is applied to both sides and is energized from both ends.

[0275] Power is supplied at a DC 100 V cycle of 15 msec.
With a pulse waveform of ˜25 msec, the pulse width is changed and given according to the temperature / energy release amount controlled by the temperature sensor. In the low heat capacity linear heating element, when the temperature is T1 detected by the temperature sensor, the surface temperature T2 of the film facing the resistance material is lower than T1. Here, T1 is preferably 120 ° C to 220 ° C, and the temperature of T2 is 0.5 ° C to 10 ° C as compared with the temperature of T1.
It is preferably lower by 0 ° C. The surface temperature T3 of the film material at the portion where the film peels from the toner surface is almost equal to T2.

Those used as fixing films are heat-resistant films having a thickness of 10 to 35 μm, such as polyester, polyperfluoroalkoxy vinyl ether, polyimide, polyether imide, and in many cases fluororesins such as Teflon (R). An endless film in which a conductive material is added to and a release agent layer is coated in a thickness of 5 μm to 15 μm is preferably used.

To drive the film, a driving force and a tension are applied by a driving roller and a driven roller, and the film is conveyed in the direction of the arrow without wrinkling or twisting. The linear velocity of the fixing device is preferably 230 mm / sec to 900 mm / sec.

The pressure roller has a rubber elastic layer having a high releasability such as silicone rubber, and is pressed against a heating body through a film material and rotated by pressure.

In the present invention, an example using an endless film as shown in FIG. 5 (a) and a film sheet feed-out shaft and take-up shaft as shown in FIG. 5 (b) are used. A structure using a film material can be preferably used. Further, a simple cylindrical one having no driving roller or the like may be used.

A cleaning mechanism may be added to the fixing device for use. As a cleaning method, a method of supplying various silicone oils to the fixing film or a method of cleaning with a pad, a roller, a web or the like impregnated with various silicone oils is used.

As the silicone oil, polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, etc. can be used. Further, a siloxane containing fluorine can also be preferably used.

An example of a sectional view of the structure of the fixing device according to the present invention will be described in detail with reference to FIGS. 5 (a) and 5 (b).

In FIG. 5 (a), reference numeral 84 is a low heat capacity linear heater fixedly supported by the apparatus, and as an example, height 1.0 mm, width 10 mm, and length 240 mm.
The alumina substrate 85 is coated with a resistance material 86 having a width of 1.0 mm, and electricity is applied from both ends in the longitudinal direction.

The energization is performed, for example, with a pulsed waveform of DC 100 V and a cycle of usually 20 msec, which is controlled by a signal from the temperature detecting element 87 and kept at a predetermined temperature.
For this reason, the pulse width is changed according to the amount of energy released, and the range is, for example, 0.5 to 5 msec. The toner is thermally fixed by bringing the transfer material 94 carrying the unfixed toner image 93 into contact with the heating member 84 controlled in this way through the moving film 88.

The film 88 used here moves without wrinkles in a state where tension is applied by the driving roller 89 and the driven roller 90. Reference numeral 95 is a pressure roller having a rubber elastic layer formed of silicone rubber or the like, and presses the heating body through the film at a total pressure of 0.4 to 2.0 N. Unfixed toner image 93 on transfer material 94
Is guided to the fixing portion by the entrance guide 96, and a fixed image is obtained by heating.

Although the above is an example of an endless belt, in the present invention, as shown in FIG. 5B, a film sheet feeding shaft 91 and a winding shaft 92 are used, and the fixing film has an end. Can also be used.

Next, the image forming apparatus used in the image forming method of the present invention will be described. In the present invention, an electrostatic latent image formed by charging and image exposure on a photoconductor is developed with a developer, and a toner image formed is transferred onto a transfer material using a contact transfer method, and then separated and fixed. By repeating the steps of cleaning and cleaning, a large number of images are formed.

(Transfer Roll) The toner image is transferred from the surface of the photoconductor to the transfer material by elastically pressing the transfer roll against the photoconductor and applying a bias voltage. As the transfer roll, an elastic body made of rubber or porous foam is used. For example, (1) Bridgestone's ion conductive type, (2) Bridgestone's electronic conductive type, (3) Toyo Polymer's foamed urethane rubicelle type, (4) Sumitomo Rubber Industries' ion conductive type, (5) Sumitomo EPDM type manufactured by Rubber Industries, (6) Epichlorohydrin type manufactured by Sumitomo Rubber Industries, (7) ENDUR manufactured by Inoac Corporation
Ion conductive type, (8) Tigers Polymer's foamed silicone type, (9) Hokushin Kogyo's foamed urethane type, (10) Shin-Etsu Polymer's foamed silicone type or (11) Nitto Kogyo's carbon black-containing Rubicell foamed type Although various types of transfer rolls such as the above can be mentioned, the foaming type is preferable.

In the image forming method of the present invention, in order to transfer the toner image on the surface of the photoconductor to the transfer material satisfactorily, the pressing force of the transfer roll on the photoconductor is 2.5 to 100 kPa.
Is preferable, and more preferably 10 to 80 kPa.

When the pressing force is 2.5 to 100 kPa, the transfer of the toner image is sufficient, and it is possible to prevent transfer of the crystalline substance having releasability in the toner to the surface of the photoreceptor. Occurrence of defects can also be prevented. Further, the impact at the time of releasing the pressure of the transfer roll is reduced, image defects due to transfer deviation can be prevented, and damage to the photoconductor can also be prevented.

As the characteristics required for the transfer roll, for example, the impact resilience, electric resistance, surface hardness, etc. are important. The impact resilience of the elastic body of the transfer roll is preferably 30 to 70%. When the impact resilience is 30 to 70%, a sufficient pressing force to the photoconductor for transferring the toner image can be obtained, so that a good transfer rate can be obtained.
In addition, since the impact at the time of transfer can be reduced, the occurrence of image defects such as transfer deviation can be prevented. The impact resilience is J
It is measured by the measuring method of IS K7311.

The transfer roll is required to have appropriate conductivity so that a bias voltage for toner image transfer can be applied, and the electric resistance value measured by the following measuring method is 1
It is preferable that it is × 10 ³ to 1 × 10 ¹³ Ω.

(Measurement method) Diameter 16 mm, length 310 mm
The transfer roll in which an elastic body having a thickness of 4 mm is provided on the rotating shaft of No. 2 is pressed against an aluminum tube having a diameter of 30 mm with a force of 17 kPa, and the rotating shaft of the transfer roll is set at 20 ° C. and 50% RH. Measure the electrical resistance between the aluminum tubes.

The surface hardness of the elastic body measured by an Asker C hardness meter is preferably 20 to 70 degrees. A transfer roll made of an elastic material having an Asker C hardness of 20 to 70 degrees is preferable because transfer is performed properly and image defects such as transfer deviation do not occur.

Next, an image forming apparatus used in the image forming method of the present invention for forming a large number of images will be described with reference to the drawings. The image forming method for forming a large number of images of the present invention means that an electrostatic latent image formed by performing charging and image exposure on a photoconductor is used as a developer containing a toner for developing an electrostatic latent image. It is an image forming method in which a toner image formed by development is transferred to a transfer material by using a contact transfer method, and then each step of separating, fixing and cleaning is repeated to form a large number of images.

FIG. 6 is a schematic structural view showing an example of an image forming apparatus using a transfer roll. In FIG. 6, the photoconductor 10
Is an organic photoconductor rotating in the direction of the arrow, 11 is a charger for uniformly charging the photoconductor, and the charger may be a corona discharger, a roller charger, or a magnetic brush charger. . Reference numeral 12 denotes a digital image exposure light using a semiconductor laser, a light emitting diode, etc., and an electrostatic latent image is formed on the photoconductor by the image exposure light. This electrostatic latent image is developed in a contact or non-contact manner by a developing device 13 containing a developer containing a toner having a volume average particle diameter of 3 to 9 μm, and a toner image is formed on the photoreceptor. In the present invention, digital image exposure is particularly preferable as the exposure, but analog image exposure may be performed.

As a scanning optical system optically modulated by a digital image signal from a computer or a copy manuscript used in this image forming method and apparatus, an acousto-optic modulator is interposed in a laser optical system, and the acousto-optic modulator is used to emit light. There is a device for modulating and a device for directly modulating the laser intensity by using a semiconductor laser. These scanning optical systems perform spot exposure on a uniformly charged photoconductor to form a dot-shaped image.

The beam emitted from the above-mentioned scanning optical system has a circular or elliptical luminance distribution which is approximate to a normal distribution in which the skirts spread to the left and right. For example, in the case of a laser beam, it is usually the main beam on the photoconductor. One or both of the scanning direction and the sub-scanning direction is an extremely narrow round or elliptical shape of 20 to 100 μm.

The toner image is transferred onto the transfer material P, which is conveyed at the same timing, by the transfer roll 15 under the application of a DC bias with a pressing force of 2.5 to 100 kPa, preferably 10 to 80 kPa.

The DC bias power supply 16 for applying a bias to the transfer roll 15 is preferably a constant current power supply or a constant voltage power supply, and in the case of the constant current power supply, it is 5 to 15 μA.
In the case of a constant voltage power supply, the absolute value is 400 to 1500
V. The transfer material P on which the image has been transferred by the transfer roll 15 is separated from the photoconductor 10 by the separation electrode 14 and is conveyed to a fixing device (not shown) to be heated and fixed.

The surface of the photoconductor after the transfer is cleaned by the cleaning blade 17, and then the charge is removed by the charge removing lamp (PCL) 18 to prepare for the next image formation. Reference numeral 19 is a paper feed roller, and 20 is a fixing device.

(Intermediate Transfer Member) In the present invention, the transfer of the toner image from the photosensitive member to the transfer material can also be performed by a system using an intermediate transfer member. That is, an image forming unit (image forming unit) is provided for each of the four color developers, a visible image for each color is formed on each photoconductor in each image forming unit, and these visible images are sequentially transferred to an intermediate transfer member. After being collectively transferred to a transfer material (usually plain paper, it is not particularly limited as long as it can be transferred. In particular, an OHP sheet is preferable as the transfer material in the present invention) and then fixed to form a color image. It can also be preferably used in the method of obtaining.

An image forming method in which images of a plurality of colors used in the image forming apparatus of the present invention are formed in the image forming unit and are sequentially transferred to the same intermediate transfer member in an overlapping manner will be described with reference to the drawings. . FIG. 7 is a schematic configuration diagram showing an example of an image forming apparatus using an intermediate transfer body (transfer belt).

In FIG. 7, the image forming apparatus for obtaining a color image is provided with a plurality of image forming units, each image forming unit forms a visible image (toner image) of a different color, and the toner image is formed. This is an image forming method in which images are sequentially transferred and superposed on the same intermediate transfer member.

Here, the first, second, third, and fourth image forming units Pa, Pb, Pc, and Pd are arranged in parallel, and each of the image forming units is a photosensitive member which is an electrostatic latent image forming body. It comprises bodies 1a, 1b, 1c and 1d. The photoconductors 1a, 1b, 1c and 1d have the latent image forming portion 2 on the outer peripheral side thereof.
a, 2b, 2c and 2d, developing units 3a, 3b, 3c and 3d, transfer discharge units 4a, 4b, 4c and 4d, a cleaning device 5 having a cleaning member and a rubber blade.
a, 5b, 5c and 5d, and chargers 6a, 6b, 6c and 6d are arranged.

With such a structure, first, a latent image of the original component image, for example, a yellow component color is formed on the photoconductor 1a of the first image forming unit Pa by the latent image forming section 2a. The latent image is formed into a visible image with the developer containing yellow toner in the developing section 3a, and transferred to the transfer belt 21 in the transfer discharge section 4a.

On the other hand, while the yellow toner image is being transferred to the transfer belt 21 as described above, a latent image of magenta component color is formed on the photoconductor 1b in the second image forming unit Pb, and then the developing unit is formed. In 3b, a visible image is formed with a developer containing magenta toner. The visible image (magenta toner image) is transferred to the predetermined position of the transfer belt 21 in an overlapping manner when the transfer belt, which has been transferred by the first image forming unit Pa, is carried into the transfer discharge section 4b. It

The third and fourth steps are performed in the same manner as described above.
The image forming units Pc and Pd form images of cyan component color and black component color, and the cyan toner image and the black toner image are transferred on the same transfer belt in an overlapping manner. When such an image forming process is completed, a multicolor superimposed image is obtained on the transfer belt 21. On the other hand, the residual toner is removed from the photoconductors 1a, 1b, 1c and 1d after the transfer by the cleaning devices 5a, 5b, 5c and 5d, and the photoconductors are provided for the subsequent latent image formation.

The transfer belt 21 is used in the image forming apparatus. In FIG.
Is conveyed from the right side to the left side, and in the conveying process, each color transfer image is transferred through each of the transfer discharge parts 4a, 4b, 4c and 4d in each of the image forming units Pa, Pb, Pc and Pd.

The transfer belt 21 is the fourth image forming unit P.
After passing d, an AC voltage is applied to the separation charge-eliminating discharger 22d, the transfer belt 21 is discharged, and the toner images are collectively transferred to the transfer material P. After that, the transfer material P enters the fixing device 23, is fixed, and is discharged from the discharge port 25 to obtain a color image.

Incidentally, reference numerals 22a, 22b, 22c and 22d in the figure are separation charge-eliminators, and the transfer belt 21 which has finished transferring the toner image is cleaned by a cleaning device 24 using both a brush-like cleaning member and a rubber blade. The transfer residual toner is cleaned and prepared for the next image formation.

As described above, even if a long transfer belt 21 such as a conveyor belt is used and a multicolor superimposed image is formed on the transfer belt 21 and the transferred images are collectively transferred to a transfer material, the image is not transferred. The forming units may be provided with independent transfer belts, and the transfer belts may be sequentially transferred to the transfer material.

As the transfer belt, for example, polyimide, polyether, polyamide, tetrafluoroethylene / perfluorovinyl ether copolymer or the like having a surface resistance of 10 ¹⁴ Ω or more and a high resistance film of about 20 μm thick In addition, a conductive agent was added to fluorine-based or silicon-based resin to make the surface resistance 10 ⁵ to 10 ⁸ Ω 5-1
An endless film provided with a release layer having a thickness of 5 μm is used.

In the image forming method of the present invention, the toner image formed in the developing step is fixed in the fixing step after being transferred to the transfer material as described above. A so-called contact heating method can be mentioned as a suitable fixing method used in the present invention. In particular, as the contact heating method, there are a heat pressure fixing method, a heat roll fixing method, and a pressure contact heating fixing method in which fixing is performed by a rotating pressure member including a fixedly arranged heating body.

In the heat roll fixing system, an upper roller having a heat source inside a metal cylinder made of iron or aluminum whose surface is coated with tetrafluoroethylene or polytetrafluoroethylene-perfluoroalkoxyvinyl ether copolymers is used. It is formed of a lower roller made of silicone rubber or the like. As a heat source, a linear heater is used, and the surface temperature of the upper roller is 120 to
A typical example is heating to about 200 ° C. In the fixing section, pressure is applied between the upper roller and the lower roller to deform the lower roller and form a so-called nip. The nip width is 1 to 10 mm, preferably 1.5 to 7 mm. The fixing linear velocity is 40 mm / sec to 600 mm / se
c is preferred.

A fixing cleaning mechanism may be provided for use. As this method, a method of supplying silicone oil to a roller or a film after fixing, or a method of cleaning with a pad, roller, web, etc. impregnated with silicone oil can be used.

Further, the image forming apparatus used in the present invention may have a toner recycling mechanism for recycling the untransferred toner remaining on the surface of the photoreceptor. The method for carrying out toner recycling is not particularly limited, but, for example, the toner collected in the cleaning section is mixed with a replenishment toner hopper, a developer or a replenishment toner by an intermediate chamber by a conveyor or a conveyor screw. And a method of supplying it to the developing device. A method of returning directly to the developing unit or a method of mixing and supplying the replenishment toner and the recycled toner in the intermediate chamber is preferable.

Next, FIG. 8 shows an example of a perspective view of a toner recycling member. This method is a method in which recycled toner is directly returned to the developing device.

The untransferred toner collected by the cleaning blade 130 is collected in the toner recycling pipe 140 by the conveying screw in the toner cleaning device 110, returned to the developing device 600 from the receiving port 150 of this recycling pipe, and again used as a developer. used.

FIG. 8 is also a perspective view of a process cartridge detachably mountable to the image forming apparatus of the present invention. This Figure 8
In the drawing, the photoconductor unit and the developer unit are shown separately for the sake of easy understanding of the perspective structure, but they can be detachably mounted in the image forming apparatus as a unit in which they are all integrated. In this case, the photoconductor, the developing device, the cleaning device, and the recycling member are integrated to form a process cartridge.

[0321]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto. In the text, "part" means "part by mass".

Example 1 <Production of Binder Resin Particles for Toner> [Preparation of Latex 1HML] (1) Preparation of Core Particles (First Stage Polymerization): Latex (1
Preparation of H) In a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introducing device, the following anionic surfactant (101) (101) C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ A surfactant solution (water-based medium) prepared by dissolving 7.08 g of OSO ₃ Na in 3010 g of ion-exchanged water was charged, and the solution was stirred under a nitrogen stream for 230 r.
The internal temperature was raised to 80 ° C. while stirring at a stirring speed of pm.

To this surfactant solution, 9.2 g of a polymerization initiator (potassium persulfate: KPS) was added 200 g of deionized water.
Was added to the solution of the initiator, and the temperature was adjusted to 75 ° C. Then, 70.1 g of styrene and 1 of n-butyl acrylate were added.
A monomer mixture solution consisting of 9.9 g and methacrylic acid 10.9 g was added dropwise over 1 hour, and this system was heated at 75 ° C. for 2 hours with stirring to perform polymerization (first stage polymerization), A latex (a dispersion of binder resin particles composed of a high molecular weight binder resin) was prepared. This is called "latex (1
H) ”.

(2) Formation of Intermediate Layer (Second Stage Polymerization): Preparation of Latex (1HM) In a flask equipped with a stirrer, styrene 1 was added.
In a monomer mixture liquid consisting of 05.6 g, 30.0 g of n-butyl acrylate, 6.2 g of methacrylic acid and 5.6 g of n-octyl-3-mercaptopropionic acid ester, a crystalline substance of the above formula +19) was added. A compound solution was prepared by adding 98.0 g of the represented compound (hereinafter, referred to as “Exemplified Compound (19)”), heating to 90 ° C. and dissolving.

On the other hand, an anionic surfactant (the above formula (1
01)) 1.6 g of ion-exchanged water dissolved in 2700 ml of a surfactant solution was heated to 98 ° C., and the latex solution (1H) as a dispersion of core particles was added to the surfactant solution.
After adding 28 g of solid content, a mechanical dispersion machine with a circulation path "CLEARMIX"
(Manufactured by M Technique Co., Ltd.), a monomer solution of the exemplified compound (19) is mixed and dispersed for 8 hours, and a dispersion liquid (emulsion liquid) containing emulsified particles (oil droplets) having a dispersed particle diameter (284 nm). ) Was prepared.

Next, to this dispersion (emulsion), an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water and 750 ml of ion-exchanged water were added, and the system was added to 98 Polymerization (second-stage polymerization) is performed by heating and stirring at ℃ for 12 hours, and a composite binder having a structure in which the surface of the latex (binder resin particles composed of a high molecular weight binder resin is covered with an intermediate molecular weight binder resin) A dispersion liquid of the adhered resin particles) was obtained. This is "latex (1HM)"
And

When the latex (1HM) was dried and observed with a scanning electron microscope, particles (4) containing the exemplary compound (19) not surrounded by the latex as a main component were obtained.
(0 to 1000 nm) was observed.

(3) Formation of Outer Layer (Third Stage Polymerization): Preparation of Latex (1HML) To the latex (1HM) obtained as described above, 7.4 g of a polymerization initiator (KPS) was added in 200 ml of ion-exchanged water. Was added to the initiator solution, and styrene 300 g and n-butyl acrylate 95 were added under the temperature condition of 80 ° C.
g, 15.3 g of methacrylic acid, and 10.4 g of n-octyl-3-mercaptopropionic acid ester were added dropwise over 1 hour. After completion of the dropping, polymerization (third stage polymerization) was carried out by heating and stirring for 2 hours, then cooled to 28 ° C., and a latex (a central portion made of a high molecular weight binder resin and an intermediate portion made of an intermediate molecular weight binder resin) A dispersion liquid of composite binder resin particles having a layer and an outer layer made of a low molecular weight binder resin, and containing the exemplary compound (19) in the intermediate layer was obtained. This latex is referred to as "latex (1HML)".

The composite binder resin particles constituting this latex (1HML) have peak molecular weights of 138,000, 80,000 and 13,000, and the weight average particle size of the composite binder resin particles is Diameter is 122 nm
Met.

[Preparation of 2 L of latex] 14.8 g of a polymerization initiator (KPS) was placed in a flask equipped with a stirrer.
Was added to 400 ml of ion-exchanged water to prepare an initiator solution, and 600 g of styrene, n-
Butyl acrylate 190g, methacrylic acid 30.0
g, n-octyl-3-mercaptopropionic acid ester 20.8 g of a monomer mixture solution was added dropwise over 1 hour. After completion of dropping, the mixture was heated and stirred for 2 hours for polymerization, and then cooled to 27 ° C. to obtain a latex (a dispersion liquid of binder resin particles made of a low molecular weight binder resin). This latex is referred to as "latex (2 L)".

The binder resin particles constituting this latex (2 L) have a peak molecular weight of 11,000, and the binder resin particles have a weight average particle diameter of 128 n.
It was m.

<< Production of Colored Particles >> [Production of Colored Particles 1] (Dispersion of Colorant) Anionic surfactant (101) 5
9.0 g was dissolved in 1600 ml of ion-exchanged water with stirring.
While stirring this solution, the colorant 1 shown in Table 1
A dispersion liquid of colorant particles (hereinafter referred to as “colorant dispersion liquid 1”) was added by gradually adding 0.0 g and then performing a dispersion treatment using a stirrer “CLEARMIX” (manufactured by M Technique Co., Ltd.). Was prepared). This colorant dispersion 1
The weight average particle diameter of the colorant particles in 1. was 110 nm when measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.).

(Coagulation / fusion) 420.7 g of latex 1HML (in terms of solid content), 900 g of ion-exchanged water and 200 g of "colorant dispersion liquid 1", a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. The mixture was placed in a reaction vessel (four-necked flask) equipped with and stirred. The temperature in the container is 30 ℃
Then, the pH was adjusted to 8 to 11.0 by adding a 5 mol / L sodium hydroxide aqueous solution to this solution.

Then, magnesium chloride hexahydrate 1
An aqueous solution obtained by dissolving 2.1 g in 1000 ml of ion-exchanged water was added with stirring at 30 ° C. for 10 minutes. The temperature was started after being left for 3 minutes, and this system was heated to 90 ° C. over 60 minutes. In that state, the particle size of the associated particles was measured with "Coulter Counter TA-II", and when the number average particle size reached 4 µm to 7 µm, sodium chloride 4
An aqueous solution in which 0.2 g was dissolved in 1000 ml of ion-exchanged water was added to stop grain growth, and further, as aging treatment, heating and stirring were performed at a liquid temperature of 98 ° C. for 6 hours to continue fusion bonding.

Further, 2 g of latex (dispersion liquid of binder resin particles) (96 g) was added, and heating and stirring were continued for 3 hours to fuse 2 l of latex to the surface of the agglomerated particles of latex (1HML). Where sodium chloride 40.2
g was added, the mixture was cooled to 30 ° C. under the condition of 8 ° C./min, hydrochloric acid was added to adjust pH to 2.0, and stirring was stopped. The produced salting-out, aggregation, and fused particles were filtered, washed repeatedly with ion-exchanged water at 45 ° C., and then dried with warm air at 40 ° C. to obtain colored particles 1.

The colorant dispersion state is controlled by controlling the pH in the aggregation step, the timing of adding 2 L of latex, and the stirring strength, and the coefficient of variation of the particle size and the particle size distribution is arbitrarily adjusted by classification in the liquid. did.

[Production of Colored Particles 2] In the production of colored particles 1, the colorant 2 shown in Table 1 was used in place of the colorant 1, and the pH in the aggregation step, the timing of addition of the latex 2L, and the stirring strength were controlled. As a result, the colorant dispersion state (dispersed particle size in the medium, average particle size of the colorant, etc.) is controlled as shown in Tables 1 and 2, and the particle size and particle size distribution Colored particles were obtained in the same manner except that the coefficient of variation was arbitrarily adjusted. This is designated as colored particle 2.

[Production of Colored Particles 3] In the production of colored particles 2, by controlling the pH in the aggregation step, the timing of addition of latex 2L, and the stirring strength, the colorant dispersion state as shown in Tables 1 and 2 can be obtained. Was controlled, and colored particles were obtained in the same manner except that the variation coefficient of the particle size and the particle size distribution was arbitrarily adjusted by classification in the liquid. This is called colored particle 3.

[Production of Colored Particles 4] In the production of colored particles 1, the colorant 3 shown in Table 1 was used in place of the colorant 1, and the pH in the aggregating step, the addition timing of the latex 2L, and the stirring strength were controlled. As a result, the colorant dispersion state is controlled as shown in Tables 1 and 2, and the particle size and the coefficient of variation of particle size distribution are arbitrarily adjusted by in-liquid classification to obtain colored particles in the same manner. It was This is designated as colored particle 4.

[Production of Colored Particles 5] In the production of colored particles 4, the colorant dispersion state as shown in Tables 1 and 2 is controlled by controlling the pH in the aggregation step, the timing of addition of latex 2L, and the stirring strength. Was controlled, and colored particles were obtained in the same manner except that the variation coefficient of the particle size and the particle size distribution was arbitrarily adjusted by classification in the liquid. This is called colored particle 5.

[Production of Comparative Colored Particle 6] In the production of Colored Particle 1, instead of Colorant 1, C.I.
I. Solvent Yellow 93 is used and p
The colorant dispersion state is controlled as shown in Tables 1 and 2 by controlling the addition timing of H and latex 2L and the stirring strength, and the coefficient of variation of the particle size and the particle size distribution is arbitrarily controlled by the in-liquid classification. Comparative colored particles 6 were obtained in the same manner except that the adjustment was made as described above.

[Production of Comparative Colored Particles 7] In the production of colored particles 1, C.I.
I. Pigment Yellow 174, p in the aggregation step
By controlling the timing of addition of H and latex 2L and the stirring strength, the colorant dispersion state is controlled, and further, the variation coefficient of the particle size and particle size distribution is arbitrarily adjusted by classification in the liquid. Got This is used as a comparative colored particle 7.

[Production of Comparative Colored Particles 8] In production of the colored particles 1, the dispersion time of the colorant, the pH of the aggregating step, the addition timing of the latex 2L, and the stirring strength were controlled to obtain the results shown in Tables 1 and 2. Comparative colored particles 8 were obtained in the same manner except that the colorant dispersion state was controlled as described above, and the coefficient of variation of the particle size and the particle size distribution was arbitrarily adjusted by classification in the liquid.

<< Preparation of Toner >> Coloring Particles 1 to 1 described above
5, 1% by mass of hydrophobic silica (number average primary particle size = 12 nm, degree of hydrophobicity = 68) for each of the comparative colored particles 6 to 8
And hydrophobic titanium oxide (number average primary particle size = 20 nm,
Hydrophobicity = 63) was added in an amount of 0.3% by mass and mixed by a Henschel mixer to obtain electrostatic image developing toners 1 to 5 of the present invention and comparative electrostatic image developing toners 6 to 8, respectively. .

In the preparation of the electrostatic charge image developing toner from the colored particles, there is no physical variation between the colored particles and the corresponding electrostatic charge image developing toner in terms of physical properties such as shape and particle size (shape, The particle size, shape factor, coefficient of variation of shape factor, etc. do not change).

Tables 1 and 2 show the colorant component of the obtained toner, the colorant dispersion state, the physical properties, the physical properties of the toner particle (same as the colorant particle) developer, and the like. Similar to the weight average particle size and distribution of the colorant in the toner and the area measurement method of the Voronoi polygon, the toner cross section is photographed, and then the image processing apparatus “Luzex F” (manufactured by Nireco Corporation) is used. The captured image information was arithmetically processed to measure and calculate physical property data as shown in Tables 1 and 2.

[0347]

[Table 1]

[0348]

[Table 2]

(Preparation of Developer) (Developers 1 to 4, Preparation of Comparative Developers 6 and 7: Two-Component Developer) Toners 1 to 5 for electrostatic charge image development obtained above, comparative electrostatic charge A ferrite carrier coated with a silicone binder resin and having a volume average particle diameter of 60 μm was mixed with each of the image developing toners 6 to 8 to prepare a developer having a toner concentration of 6%. These are referred to as developers 1 to 4 and comparative developers 6 and 7.

(Preparation of Developer 5 and Comparative Developer 8: One-Component Developer) Further, regarding the toner 5 and the comparative toner 8, these toners were directly used as non-magnetic one-component developers, and 5, comparative developer 8 is used.

<< Developer Evaluation Method >> (a) Evaluation of Two-Component Developers Developers 1 to 4 and comparative developers 6 and 7 are used, respectively, and a configuration similar to that of the image forming apparatus shown in FIG. 7 is used. A digital color copying machine having the same was used, and a pressure contact type heat fixing device as shown in FIG.

The specific structure of the fixing device was set as follows. The surface has a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) silicone rubber (thickness: 120 μm) 212 and an inner diameter of 40 mm.
Has a cylindrical cored bar 21 having a width of 310 mm and a heater 213 built in the central part and a thickness of 1.0 mm as a heating roller (upper roller) 241, and the surface is similarly sponge-like silicone rubber (Asker C hardness = 48: Thickness 2m
m) 2.0 mm with an inner diameter of 40 mm composed of 217
Pressure roller (lower roller) 242 having a core metal 216 of
have. Here, the nip width was 5.8 mm.
Using this fixing device, the linear velocity of printing is 250 mm / s.
set to ec.

As the cleaning mechanism of the fixing device, polydiphenyl silicone (viscosity at 20 ° C. is 10 Pa · s
The web-type feeding method was used.

The fixing temperature was set at 180 ° C. by controlling the surface temperature of the upper roll. (B) Evaluation of one-component developer By using the developer 5 and the comparative developer 8, the color image forming apparatus shown in FIG. 7 equipped with the developing device shown in FIG. 9 was used in a high temperature and high humidity environment (temperature 33 ° C.). , Relative humidity 80%), a full-color image (pixel ratio of each of Y / M / C / Bk was 15%) was continuously formed on 100,000 sheets, and a real shooting test was performed.

As the fixing device of the color image forming apparatus, a pressure contact type heat fixing device as shown in FIG. 10 was used. The specific configuration of the fixing device is as follows. Cylindrical shape (inner diameter = 30 mm, wall thickness = 1.0 m) made of an aluminum alloy with a heater 213 built in the central part
m, full width = 310 mm), the surface of the core metal 211 is made of silicone rubber (Asker C hardness 30 °, thickness 2 mm) 212
The heating roller 241 (upper roller) is formed by coating with a cylindrical shape made of iron (inner diameter = 40 mm, wall thickness =
The surface of the core metal 216 (2.0 mm) is sponge-like silicone rubber (Asker C hardness 30 °, thickness 8 mm) 217
The pressure roller 242 (lower roller) is formed by covering the heating roller and the pressure roller with 150N.
Were contacted with each other to form a nip having a width of 5.8 mm. By using this fixing device, the linear velocity of printing is 180
It was set to mm / sec. Note that the surface of the heating roller is
Coated with a tube of FA (50 μm). As a cleaning mechanism for the fixing device, dimethyl silicone (20
A web-type supply method in which a viscosity of 10 ° C. was impregnated was used. The fixing temperature was controlled by the surface temperature of the heating roller (set temperature 175 ° C.). The amount of silicone oil applied was 0.1 mg / A4.

The evaluation method of the above developer is shown below. <Chromaticity evaluation> Light source A with Macbeth Color Eye 7000
Using the STM-D65 2 degree visual field, the chromaticity of the image on the produced paper was measured and evaluated. Using a yellow developer and a cyan developer shown below, after repeated development and transfer in the order of yellow and cyan, fixing was performed and the chromaticity of the secondary color (green) image formed on the paper was the same as above. It was evaluated by the method. The toner adhesion amount is 0.4 ± 0.0 for each color.
The evaluation was performed within the range of 5 (mg / cm ² ). In the present invention, if the b ^* value of yellow is 80 or more and the a ^* value of the secondary color green is -60 or less, it is determined that the chromaticity is good.

(Preparation of Cyan Developer) In the production of the colored particles 1, C.I. I. Colored particles 9 were obtained in the same manner except that Pigment Blue was used. Then, in the preparation of the toner 1 for developing an electrostatic image,
A toner 9 for developing an electrostatic image was obtained in the same manner except that the colored particles 9 were used instead of the colored particles 1. This toner 9
Was prepared as a so-called non-magnetic one-component developer using the toner as it is, like the developer 5 and the comparative developer 8.

<Heat Resistance Evaluation> The heat resistance is evaluated by measuring the change in the tint of the front and back sides during double-sided printing. The yellow developer was used to develop the toner on the photoreceptor to form a square (5 cm × 5 cm) image, and the image was evaluated for heat resistance by the method described below.

The change in color was evaluated by the fluctuation range of b ^* before and after fixing. If this fluctuation range is large, the desired color cannot be obtained,
There will be a gap in color matching. Practically, the fluctuation range needs to be less than 2.0, preferably less than 1.0.

◎: Less than 1.0 ○: Less than 2.0 ×: 2.0 or more << Fog occurrence situation >> Under a high temperature and high humidity environment (temperature 33 ° C., relative humidity 80%), a Y (yellow) image was formed. After continuously printing 5000 sheets, after turning off the power and leaving it for 72 hours, printing again, successively observing formed images, visually counting the number of image stains (fogging). , Judged good.

⊚: 0 to 3 ∘: 4 to less than 10 x: 10 or more << Transparency evaluation of OHP image >> Regarding the transparency of an OHP image, a transmissive image (OHP image) was prepared and shown below. It was evaluated by the method. The toner adhesion amount is 0.7 ± 0.05
It was evaluated in the range of (mg / cm ² ). With respect to the fixed image, the visible spectral transmittance of the image was measured with an OHP sheet on which no toner is carried as a reference by Hitachi's "330 type self-recording spectrophotometer". With yellow toner, the spectral transmittance at 650 nm and 450 nm was measured. Was calculated and used as a measure of the transparency of the OHP image. This value is 60%
When it is above, it can be determined that the transparency is good.

⊚: 70% or more O: 60% or more x: less than 60% << Odor Evaluation >> The presence or absence of odor was evaluated by sensory evaluation. The presence or absence of odor was evaluated by counting the number of people who perceived odor by 10 evaluators who were randomly collected. When the number of people who felt odor was less than 3, it was judged that there was substantially no odor.

The results obtained are shown in Table 3.

[0364]

[Table 3]

From Table 3, as compared with the comparative sample, the sample of the present invention exhibits good chromaticity, excellent heat resistance, low fog, good OHP permeability, and odor. It is clear that there are few.

[0366]

EFFECT OF THE INVENTION According to the present invention, a toner for developing an electrostatic charge image having good chromaticity, high heat resistance, low fog, good OHP transparency, and no odor, and a method for producing the toner. And an image forming method can be provided.

[Brief description of drawings]

FIG. 1 is a stirrer used to obtain a colorant according to the present invention.

FIG. 2 is a schematic diagram illustrating toner particles having a sea-island structure according to the present invention.

FIG. 3 is a schematic diagram in which toner particles having a sea-island structure according to the present invention are divided by Voronoi polygons.

FIG. 4 is a schematic diagram illustrating toner particles having no corners and toner particles having corners.

FIG. 5 is an explanatory configuration diagram showing an example of a configuration of a fixing device applied to the present invention.

FIG. 6 is a schematic configuration diagram showing an example of an image forming apparatus using a transfer roll applied to the present invention.

FIG. 7 is a schematic configuration diagram showing an example of an image forming apparatus using a transfer belt applied to the present invention.

FIG. 8 is a perspective view of a toner recycling member.

FIG. 9 is a schematic sectional view of a developing device used in the present invention.

FIG. 10 is a schematic sectional view showing an example of a pressure contact type heat fixing device used in the present invention.

[Explanation of symbols]

101 screen 102 rotor M stirring chamber 103 Pressurized vacuum attachment 104 Pre-dispersion liquid inlet 105 Dispersion liquid outlet 107 cooling jacket 108 cooling coil 111 dispersion container 112 Stirrer 113 Stirrer shaft 10 photoconductor 11 charger 12 Digital image exposure light 13 Developer 14 Separator 15 Transfer roll 16 bias power supply 17 Cleaning blade 18 Static elimination lamp 19 Paper feed roller 20 Fixer P transfer material Pa, Pb, Pc, Pd image forming unit 1a, 1b, 1c, 1d photoconductor 2a, 2b, 2c, 2d latent image forming section 3a, 3b, 3c, 3d Development section 4a, 4b, 4c, 4d Transfer discharge unit 5a, 5b, 5c, 5d Cleaning section 6a, 6b, 6c, 6d charger 22a, 22b, 22c, 22d Separated static eliminator 23 Fixing device 24 Cleaning device 25 outlet 84 heating body 85 Alumina substrate 86 Resistance material 87 Temperature sensor 88 film 89 Drive roller 90 Driven roller 91 Feeding shaft 92 Winding shaft 93 Unfixed toner image 94 Transfer material 95 Pressure roller 51 sleeve 52 hopper 53 toner 54 drums 55 Elastic blade or elastic roller

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masafumi Uchida             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company F-term (reference) 2H005 AA06 AA15 AA21 AB03 AB06                       CA21 EA05 EA07 EA10                 2H033 BA25 BA58 BB18 BB28 BE03

Claims (15)

[Claims] 1. A toner for developing an electrostatic charge image comprising toner particles containing a binder resin and a colorant, wherein the colorant in the toner particles has an average ferret horizontal diameter of 10 nm to 500 n.
m, the proportion of the colorant having a ferret horizontal diameter of 2 nm to 300 nm is 50% by number or more, and the colorant contains a compound represented by the following general formula (1). Toner for developing electrostatic images. [Chemical 1] [In the formula, X ₁ , X ₂ , X ₃ , Y ₁ , Y ₂ and Y ₃ are respectively
Hydrogen atom, alkyl group having 1 to 3 carbon atoms, fluoroalkyl group having 1 to 3 carbon atoms, alkoxyl group having 1 to 3 carbon atoms,
Halogen atom, nitro group, sulfo group, alkaline earth metal salt or higher amine salt of sulfo group, N-phenylaminosulfonyl group, carboxyl group, alkaline earth metal salt or higher amine salt of carboxyl group, N-phenylcarbamoyl group , A ureylene group, an iminodicarbonyl group, an alkoxycarbonyl group, —CONHR ₁ (wherein R ₁ is
It represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or a phenyl group. ), —NHCOR ₂ (in the formula, R ₂ represents an alkyl group) or —SO ₂ R ₃ (in the formula, R ₃ is an alkyl group having 1 to 8 carbon atoms). ] 2. A weight average particle diameter of 2 in an aqueous dispersion medium.
The toner for developing an electrostatic charge image according to claim 1, wherein the toner particles are manufactured by using a colorant dispersed in a range of nm to 300 nm. 3. A Voronoi polyhedron having a toner particle in which a binder resin and a colorant form a sea-island structure, and formed by vertical bisectors between the centers of gravity of adjacent islands in the toner particle. The average value of the square area is 20000 nm ^{2 to} 12000
3. The toner for developing an electrostatic charge image according to claim 1, wherein the toner has a particle size variation coefficient of 0 nm ² and a variation coefficient of the area of the Voronoi polygon is 25% or less. 4. A Voronoi polyhedron having a toner particle in which a binder resin and a colorant form a sea-island structure, and formed by vertical bisectors between the centers of gravity of adjacent islands in the toner particle. The average value of the square area is 40,000 nm ² to 10,000
4. The variation coefficient of the area of the Voronoi polygon is 0 nm ² and is 20% or less.
5. The toner for developing an electrostatic charge image according to any one of 1. 5. A Voronoi polyhedron having toner particles in which a binder resin and a colorant form a sea-island structure, and formed by vertical bisectors between the centers of gravity of adjacent islands in the toner particles. The average value of the square area is 20000 nm ^{2 to} 12000
Is 0 nm ^2, and claim that the island that forms the Voronoi polygons having an area of the Voronoi polygon having 160000Nm ² or more areas, characterized in that a 3% by number to 20% by number of the total island 5. The toner for developing an electrostatic charge image according to any one of 1 to 4. 6. The toner according to claim 1, wherein the ratio of the toner particles having no corners to all the toner particles is 50 number% or more, and the number variation coefficient in the number particle size distribution is 27% or less. 2. The toner for developing an electrostatic charge image according to item 1. 7. The ratio of the toner particles having a shape factor in the range of 1.01 to 1.6 to all the toner particles is 65% by number.
The electrostatic charge according to any one of claims 1 to 6, wherein the variation coefficient of the shape factor is 16% or less and the number variation coefficient in the number particle size distribution is 27% or less. Toner for image development. 8. A step of producing a binder resin by polymerizing a polymerizable monomer in an aqueous medium in producing the toner for developing an electrostatic charge image according to any one of claims 1 to 7. A method for producing an electrostatic charge image developing toner, comprising: 9. In producing the electrostatic image developing toner according to claim 1, the toner particles undergo a step of aggregating and fusing the binder resin particles in an aqueous medium. A method for producing a toner for developing an electrostatic charge image, which is produced. 10. In producing the electrostatic image developing toner according to claim 1, the toner particles are binder resin particles formed by polymerizing a polymerizable monomer. A method for producing an electrostatic charge image developing toner, characterized in that the toner is produced through a step of salting out / fusing with the colorant particles. 11. In producing the toner for developing an electrostatic image according to claim 1, the toner particles include binder resin particles obtained by a multi-stage polymerization method and colorant particles. A method for producing a toner for developing an electrostatic charge image, which is produced through a step of salting out / fusing. 12. In producing the toner for developing an electrostatic charge image according to claim 1, the toner particles are provided on the surface of the colored particles containing a resin and a colorant,
A method for producing a toner for developing an electrostatic charge image, which is produced by a step of fusing binder resin particles by a salting out / fusing method to form a binder resin layer. 13. An electrostatic charge image developing toner manufactured by using the method for manufacturing an electrostatic charge image developing toner according to claim 8. Description: 14. An image forming method comprising a step of converting an electrostatic latent image formed on a photoreceptor into a visible image, transferring the visible image onto a recording medium, and heating and fixing the image. An image formation, which is carried out by a fixing device having a film, and wherein the visible image formation is carried out by using the toner for developing an electrostatic charge image according to any one of claims 1 to 7 and 13. Method. 15. The electrostatic latent image is formed by irradiating a photoconductor with digital exposure.
The image forming method described in 1 ..