JP2002131978A - Electrostatic charge image developing toner, method for producing the same and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner which ensures a high image density, low fog, a good transfer rate, good uniformity of halftone and superior thin line reproducibility, and to provide an image recording method and an image forming method each using the toner. SOLUTION: The electrostatic charge image developing toner is produced through a process in which a dispersion of resin particles is prepared by polymerizing a polymerizable monomer in an aqueous medium and the resin particles are agglomerated and fused after salting-out in the aqueous medium in the presence of a compound of formula (1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image, a method for producing the same, and an image forming method.

[0002]

2. Description of the Related Art At present, an electrostatic latent image developing method represented by an electrophotographic method is widely used in an image forming method of a printer, a copying machine, a facsimile or the like.

[0003] The reason for this is that it is a highly complete method for stably obtaining a high-speed and high-quality image, but some problems still remain.

For example, conventionally, in a toner prepared by a pulverization method, the material dispersed in the toner is unevenly present on the fracture surface, and the surface properties of the toners are difficult to be constant, and variations occur in a transfer process. And the color reproducibility as a color image is reduced.

On the other hand, it is desired to reduce the particle size of the electrostatic latent image developing toner from the viewpoint of high image quality. In recent years, polymerization toners have been actively developed as a method for producing small particle size toners. The polymerized toner is prepared by associating or salting-out, aggregating, and fusing the resin particles and, if necessary, the colorant particles to prepare an irregular shaped toner, or dispersing a radical polymerizable monomer and a colorant. Then, there is a method in which droplets are dispersed in an aqueous medium or the like so as to have a desired toner particle diameter, and suspension polymerization is performed.

[0006] However, the toner particles produced by applying the suspension polymerization method can form a spherical toner having a uniform surface property, so that the uniformity among the toners is high, but the shape is spherical. As a result, the adhesion to the latent image carrier is increased, and there has been a problem that transferability is reduced.

Therefore, Japanese Patent Application Laid-Open No. 11-194540 discloses that
A non-spherical shape characterized by being produced by treating a resin particle polymerized in an aqueous medium containing a surfactant with an aggregating agent having a concentration higher than the critical aggregation concentration of the resin particle and an organic solvent infinitely soluble in water. Disclosed are particles.

In the technique described above, the use of a divalent or trivalent metal salt as an aggregating agent provides an excellent uniformity of shape and uniformity of charge amount, and a highly sharp image can be obtained.
The presence of the trivalent or trivalent metal salt raises the Krafft point of the surfactant and forms a precipitate that is hardly soluble in water. This precipitate exists in a state where it adheres to the toner even after the colored particles, that is, the toner is separated from the aqueous medium, and fogging is likely to occur under high temperature and high humidity, and transferability tends to decrease. there were.

On the other hand, it is necessary to control the molecular weight distribution of the toner resin from the viewpoint of stabilizing the fixability of the toner. For example, in order to suppress high-temperature offset, it is necessary to improve the elastic modulus at high temperature, and it is preferable to increase the high molecular weight component. On the other hand, in order to improve the adhesion to an image forming support (recording material or recording paper) such as paper, it is preferable to increase the low molecular weight component. In order to satisfy such contradictory functions, it is necessary to increase the molecular weight distribution of the resin.
Therefore, there has been a demand for a solution to the above problems.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic image having a high image density, low fog, good transfer rate and good halftone homogeneity, and excellent fine line reproducibility. An object of the present invention is to provide a developing toner, an image recording method using the same, and an image forming method.

[0011]

The above objects of the present invention have been attained by the following items 1 to 19.

In the prior art, it has been considered that the surfactant or metal element contained in the aqueous medium used in the production process in the produced toner remains unfavorable in terms of the performance of the toner.

However, the present inventors have achieved improvement in the performance of the toner by leaving a specific amount of these surfactants and metal elements in the toner, which cannot be predicted from conventional technical ideas. is there.

1. A polymerizable monomer is polymerized in an aqueous medium to prepare a dispersion of resin particles. In the aqueous medium, the resin particles are salted in the presence of the surfactant represented by the general formula (1). A toner for developing an electrostatic charge image, which is manufactured through a process of precipitation, aggregation and fusion.

2. A polymerizable monomer is polymerized in an aqueous medium to prepare a dispersion of resin particles. In the aqueous medium, the resin particles are salted in the presence of the surfactant represented by the general formula (1). After the steps of precipitation, aggregation, and fusion, the resin particles are produced through a step of separating from the aqueous medium and drying, and the resin particles are surfactants represented by the general formula (1). The toner for developing electrostatic images according to the above item 1, which contains 1 to 1000 ppm of

3. A polymerizable monomer is polymerized in an aqueous medium to prepare a dispersion of resin particles. In the aqueous medium, the resin particles are salted in the presence of the surfactant represented by the general formula (2). A toner for developing an electrostatic charge image, which is manufactured through a process of precipitation, aggregation and fusion.

4. A polymerizable monomer is polymerized in an aqueous medium to prepare a dispersion of resin particles. In the aqueous medium, the resin particles are salted in the presence of the surfactant represented by the general formula (2). After the steps of precipitation, agglomeration, and fusion, the resin particles are produced through a step of separating and drying the resin particles from the aqueous medium, and the resin particles are surfactants represented by the general formula (2). The toner for developing an electrostatic image according to the above item 3, wherein the toner comprises 1 to 1000 ppm.

5. A polymerizable monomer is polymerized in an aqueous medium to prepare a dispersion of resin particles. In the aqueous medium, the surfactant represented by the general formula (1) or the general formula (2) and a divalent Or a step of salting out, coagulating, and fusing the resin particles in the presence of a trivalent metal salt, and then a step of separating and drying the resin particles from the aqueous medium, and Is a surfactant represented by the general formula (1) or the general formula (2) in an amount of 1 to 1000 ppm, and a divalent or trivalent metal element used as an aggregating agent in a total of 250 to 20.
The toner for developing an electrostatic image according to any one of the above items 1 to 4, wherein the toner is contained at 000 ppm.

6. 6. The toner for developing an electrostatic image according to the above item 5, comprising a total of 350 to 35000 ppm of a divalent or trivalent metal element used as an aggregating agent and a monovalent metal element added as an aggregating stopper.

[7] FIG. A dispersion containing at least resin particles obtained by polymerizing a polymerizable monomer in an aqueous medium is prepared, and in the aqueous medium, the resin particles are salted out, aggregated, and fused in the presence of a metal salt. A toner for developing an electrostatic image, wherein the toner is manufactured through a process of producing colored particles by separating the obtained colored particles from the aqueous medium at a temperature higher than the Kraft point.

8. A dispersion liquid containing at least resin particles obtained by polymerizing a polymerizable monomer in an aqueous medium is prepared, and an interface represented by the general formula (1) or the general formula (2) is prepared in the aqueous medium. In the presence of an activator and a metal salt, the resin particles are salted out, agglomerated, fused to produce colored particles, and the obtained colored particles are separated from the aqueous medium at a temperature equal to or higher than the Kraft point. A toner for developing an electrostatic image, which is manufactured.

9. 9. The toner for developing an electrostatic image according to any one of items 1 to 8, wherein the number of toner particles having a shape factor in the range of 1.0 to 1.6 is 65% by number or more.

10. The toner for developing an electrostatic image according to any one of Items 1 to 9, wherein the number of toner particles having a shape factor in the range of 1.2 to 1.6 is 65% by number or more.

11. The toner for developing an electrostatic image according to any one of Items 1 to 7, wherein the toner particles having no corners account for 50% by number or more.

12. Number average particle diameter of toner is 3 to 8 μm
12. The toner for developing an electrostatic image according to any one of the above items 1 to 11, wherein

13. When the particle size of the toner particles is D (μm), the natural logarithm lnD is plotted on the horizontal axis, and the horizontal axis is 0.2
In the histogram showing the number-based particle size distribution classified into three intervals, the relative frequency (m1) of the toner particles included in the most frequent class and the toner particles included in the next most frequent class after the most frequent class (M) with relative frequency (m2) of
The toner for developing an electrostatic image according to any one of Items 1 to 12, wherein the toner is 70% or more.

14. A polymerizable monomer is polymerized in an aqueous medium to prepare a dispersion of resin particles. In the aqueous medium, the surfactant represented by the general formula (1) or the general formula (2) and a divalent Electrostatic charge image development, comprising a step of salting out, aggregating and fusing the resin particles in the presence of a metal salt or a trivalent metal salt, and a step of separating and drying the resin particles from the aqueous medium. Of manufacturing toner for toner.

15. A dispersion containing at least resin particles obtained by polymerizing a polymerizable monomer in an aqueous medium is prepared, and in the aqueous medium, the resin particles are salted out, aggregated, and fused in the presence of a metal salt. A method for producing a toner for developing an electrostatic image, characterized in that the coloring particles are produced from the aqueous medium at a temperature equal to or higher than the Kraft point.

16. A dispersion containing at least resin particles obtained by polymerizing a polymerizable monomer in an aqueous medium is prepared, and the surface activity represented by the general formula (1) or (2) is adjusted in the aqueous medium. Salting out, agglomerating and fusing the resin particles in the presence of an agent and a metal salt to produce colored particles, and separating the obtained colored particles from the aqueous medium at a temperature above the Kraft point. Of producing a toner for developing electrostatic images.

17. A dispersion of resin particles is prepared in an aqueous medium, and the resin particles are dispersed in the aqueous medium in the presence of the surfactant represented by the general formula (1) or the general formula (2). The method according to the above item 16, further comprising a step of obtaining toner particles by salting out, aggregating, and fusing together with the colorant dispersed in the aqueous medium, and a step of separating and drying the obtained toner particles from the aqueous medium. A method for producing a toner for developing a charge image.

18. In the step of separating and drying the toner particles from the aqueous medium, the toner particles are separated from the aqueous medium at a temperature equal to or higher than the Kraft point of the surfactant represented by the general formula (1) or (2). 18. The method for producing a toner for developing an electrostatic image according to the item 17, wherein

19. Forming an electrostatic image on the electrostatic image carrier, developing the electrostatic image with a developer containing an electrostatic image developing toner to form a toner image, and forming the toner image on a transfer member. 14. An image forming method including a transferring step, wherein the electrostatic image developing toner according to any one of 1 to 13 above is used as the electrostatic image developing toner.

Hereinafter, the present invention will be described in detail. In the present invention, a dispersion of resin particles is prepared by polymerizing a polymerizable monomer in an aqueous medium.
In the presence of a polyoxyethylene alkyl ether sulfate having a specific structure according to the above, salting out the resin particles, agglomeration, through a step of fusing, for electrostatic image development characterized by being manufactured The toner for developing an electrostatic image of the present invention is a toner having better shape uniformity and charge amount distribution as compared with a toner produced using a conventionally known emulsion polymerization method or suspension polymerization method. It was found that a toner having excellent sharpness, no fogging under high temperature and high humidity, and excellent transferability was obtained. In the salting-out, coagulation, and fusion steps, it is preferable to use a divalent or trivalent metal salt as a coagulant.

In the formulas (1) and (2), the dispersion of resin particles relating to the toner for developing an electrostatic image of the present invention is prepared, and salting out, agglomeration, and fusion of the important particles are present. The surfactant represented will be described.

In the general formulas (1) and (2), R ₁ represents an alkyl group or an arylalkyl group having 6 to 22 carbon atoms, preferably an alkyl group or an arylalkyl group having 8 to 20 carbon atoms, More preferably, it has 9 carbon atoms.
To 16 alkyl groups or arylalkyl groups.

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, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like.

The arylalkyl group represented by R ₁ includes a benzyl group, a diphenylmethyl group, a cinnamyl group,
Examples include a styryl group, a trityl group, and a phenethyl group.

In the general formulas (1) and (2), R ₂ represents an alkylene group having 2 to 6 carbon atoms, preferably an alkylene group having 2 to 3 carbon atoms.

Examples of the alkylene group having 2 to 6 carbon atoms represented by R ₂ include an ethylene group, a trimethylene group, a tetramethylene group, a propylene group and an ethylethylene group.

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

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

Hereinafter, specific examples of the surfactant represented by the general formulas (1) and (2) will be shown, but the present invention is not limited thereto.

Compound (101): C ₁₀ H ₂₁ (OCH ₂ CH 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 Na compound (104): C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₃ SO ₃ Na 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 Na In the present invention, the charge retention function of the toner is kept in a good state, fog generation under high temperature and high quality is suppressed, and transferability is improved. From the viewpoint of improvement, also suppress the rise 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 (1) and (2) in the toner for developing an electrostatic image of the present invention is preferably 1 to 1000 p.
pm is preferable, more preferably 5 to 500 ppm, and particularly preferably 7 to 100 ppm.

By adding a surfactant in the above-mentioned range to the toner, the chargeability of the electrostatic image developing toner of the present invention is always uniformly and stably provided without being influenced by the environment. , Can be maintained.

The method for measuring the content of the surfactant represented by the above general formulas (1) and (2) in the toner for developing an electrostatic image of the present invention is as follows.

1 g of the toner was dissolved in 50 ml of chloroform, and a surfactant was extracted from the chloroform layer with 100 ml of ion-exchanged water.
Extracted with ion-exchanged water once more, dilute a total of 200 ml of extract (aqueous layer) to 500 ml, color the diluted solution as a test solution with methylene blue according to the method specified in JIS 33636, measure the absorbance, and prepare separately From the calibration curve thus obtained, the content in the toner was measured.

The fields represented by the general formulas (1) and (2)
The structure of the surfactant is based on the above extract ¹Using H-NMR
Analysis and structure determination.

In the present invention, a metal salt is preferably used as a coagulant in the step of salting out, coagulating, and fusing the resin particles from a dispersion of the resin particles prepared in an aqueous medium. A trivalent or trivalent metal salt is used as a flocculant. The reason is that the divalent or trivalent metal salt has a smaller critical aggregation concentration (coagulation value or coagulation point) than the monovalent metal salt.

The metal salt used as a flocculant or a flocculant according to the present invention will be described.

The metal salt may be a monovalent metal, for example, a salt of an alkali metal such as sodium, potassium or lithium.
Divalent metals, for example, salts of alkaline earth metals such as calcium and magnesium, divalent metal salts such as manganese and copper, iron,
Examples thereof include trivalent metal salts such as aluminum. Specific examples of these metal salts are shown below.

Specific examples of the metal salt of a monovalent metal include sodium chloride, potassium chloride, lithium chloride and the like. Examples of the metal salt of a divalent metal include magnesium chloride, calcium chloride, calcium nitrate, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate.
Examples of the trivalent metal salt include aluminum chloride and iron chloride. These are appropriately selected according to the purpose.

The above-mentioned critical aggregating concentration is an index relating to the stability of the dispersion in the aqueous dispersion.
The concentration at the point where aggregation occurs is shown. This critical aggregation concentration varies greatly depending on the latex itself and the dispersant.
For example, Seizo Okamura et al., Polymer Chemistry 17, 601 (19
60), etc., and the value can be known according to these descriptions.

As another method, a desired salt is added at a different concentration to a target particle dispersion, and the dispersion of the target is dispersed.
It is also possible to measure the potential and determine the salt concentration at the point where the ζ potential starts to change as the critical aggregation concentration.

The polymer fine particle dispersion is treated using the above-described metal salt according to the present invention so as to have a concentration equal to or higher than the critical aggregation concentration. At this time, of course, whether to add the metal salt directly or as an aqueous solution is arbitrarily selected depending on the purpose. In the case of adding as an aqueous solution, the added metal salt needs to be at or above the critical aggregation concentration of the polymer particles with respect to the volume of the polymer particle dispersion and the total volume of the metal salt aqueous solution.

The concentration of the metal salt used as the flocculant is
The concentration is not less than the critical aggregation concentration, but is preferably 1.2 times or more, more preferably 1.5 times or more the critical aggregation concentration.

It should be noted that composite resin particles (a case where the particles have a multilayer structure or other components such as additives are contained in the particles are called composite resin particles) and colorant particles are dispersed. The temperature of the dispersion when the coagulant is added to the existing dispersion is preferably equal to or lower than the glass transition temperature (Tg) of the composite resin particles, and specifically, is in the range of 5 to 55 ° C. Preferably, it is more preferably 10 ° C to 45 ° C.

When the temperature of the dispersion at the time of adding the flocculant is
When the temperature is equal to or higher than the glass transition temperature (Tg) of the composite resin particles, it is difficult to control the particle size, and large particles are easily generated.

In the step of salting out, agglomeration and fusion, the temperature of the dispersion liquid in which the composite resin particles and the colorant particles are dispersed is determined by the glass transition temperature (T
g) At the following times, the flocculant is added while stirring the dispersion, and then immediately heating of the dispersion is started,
It is preferable that the temperature be equal to or higher than the glass transition temperature (Tg) of the composite resin particles.

In the present invention, the resin particles and the colorant are salted out, agglomerated, and fused in an aqueous medium to obtain colored particles (in the present invention, referred to as toner particles). When separating 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, more preferably at a temperature in the range of Kraft point to (Kraft point + 20 ° C). is there.

The above-mentioned Krafft point is a temperature at which an aqueous solution containing a surfactant starts to become cloudy, and the Krafft point is measured as follows.

<< Measurement of Kraft Point >> A solution is prepared by adding an actually used amount of a coagulant to an aqueous medium used in the steps of salting out, coagulation, and fusion, ie, a surfactant solution. For 5 days. The solution was then heated gradually with stirring until it became clear. The temperature at which the solution became clear is defined as the Krafft point.

From the viewpoint of suppressing excessive charging of the toner particles and imparting a uniform charging property, the toner for developing an electrostatic image of the present invention is particularly required to stabilize and maintain the charging property with respect to the environment. The metal elements described above (in the form of metal,
Metal ions, etc.) in the toner of 250 to 20
The content is preferably 000 ppm, more preferably 800 to 5000 ppm.

In the present invention, the total value of the divalent (trivalent) metal element used for the coagulant and the monovalent metal element added as the coagulation terminator described later is 350 to 35,000 pp.
m is preferable.

The amount of metal ions remaining in the toner is measured using a fluorescent X-ray analyzer “System 3270” (manufactured by Rigaku Denki Kogyo Co., Ltd.) using a metal species of a metal salt used as an aggregating agent (for example, (E.g., calcium derived from calcium chloride). As a specific measuring method, a plurality of toners having a known content ratio of the coagulant metal salt are prepared, 5 g of each toner is pelletized, and the content ratio of the coagulant metal salt (mass p
pm) and the relationship (calibration curve) between the fluorescent X-ray intensity (peak intensity) from the metal species of the metal salt is measured. Next, the toner (sample) whose content ratio of the coagulant metal salt is to be measured is similarly pelletized, and the fluorescence X from the metal species of the coagulant metal salt is determined.
By measuring the linear intensity, the content ratio, that is, the “remaining amount of metal ions in the toner” can be obtained.

The method for producing the toner for developing an electrostatic image of the present invention will be described. The toner of the present invention forms composite resin particles in the absence of a colorant, adds a dispersion of the colorant particles to a dispersion of the composite resin particles, salt-out the composite resin particles and the colorant particles, It is prepared by coagulation and fusion.

As described above, by performing the preparation of the composite resin particles in a 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 fixing device is not stained or the image is not stained due to the accumulation of the toner.

In addition, as a result of reliably performing the polymerization reaction for obtaining the composite resin particles, no monomer or oligomer remains in the obtained toner particles. No unpleasant odor is generated in the heat fixing step.

Further, since the surface characteristics of the obtained toner particles are uniform and the charge amount distribution is sharp, an image having excellent sharpness can be formed for a long period of time.

The “composite resin particles” constituting the toner of the present invention are composed of a resin having a different molecular weight and / or composition from the resin forming the core particles so as to cover the surface of the core particles made of the resin. Alternatively, it refers to a resin particle having a multilayer structure in which two or more coating layers are formed.

The “center (core)” of the composite resin particles refers to “core particles” constituting the composite resin particles.

The “outer layer (shell)” of the composite resin particles refers to the outermost layer of “one or more coating layers” constituting the composite resin particles.

The “intermediate layer” of the composite resin particles refers to a coating layer formed between a central portion (core) and an outer layer (shell).

The molecular weight distribution of the composite resin particles is not monodisperse, and the composite resin particles generally have a molecular weight gradient from the center (core) to the outer layer (shell).

In the present invention, it is preferable to use the “multi-stage polymerization method” to obtain the composite resin particles from the viewpoint of controlling the molecular weight distribution, that is, from the viewpoint of securing the fixing strength and the offset resistance. In the present invention, the “multi-stage polymerization method” for obtaining composite resin particles refers to a method in which a monomer (n) is polymerized (n-th stage), and a monomer The polymer (n + 1) is subjected to a polymerization treatment (the (n + 1) th step), and a polymer of the monomer (n + 1) (dispersion and / or composition of the resin of the resin particle (n) is formed on the surface of the resin particle (n)) A method of forming a coating layer (n + 1) made of different resins) will be described.

Here, when the resin particles (n) are core particles (n = 1), the “two-stage polymerization method” is performed, and when the resin particles (n) are composite resin particles (n ≧ 2). Is a multi-stage polymerization method of three or more stages.

A plurality of resins having different compositions and / or molecular weights are present in the composite resin particles obtained by the multi-stage polymerization method. Therefore, the toner obtained by salting out, aggregating, and fusing the composite resin particles and the colorant particles has extremely small variations in composition, molecular weight, and surface characteristics among the toner particles.

According to such a toner having a uniform composition, molecular weight and surface characteristics among toner particles, good adhesion (high fixing strength) to an image support can be obtained in an image forming method including a fixing step by a contact heating method. ), The offset resistance and the anti-winding property can be improved, and an image having an appropriate gloss can be obtained.

A specific example of the method for producing the toner for developing an electrostatic image of the present invention is as follows. (1) The release agent and / or the crystalline polyester are added to a region other than the outermost layer (the central portion or the intermediate layer). (I) for obtaining composite resin particles prepared so as to be contained in (1), (2) salting out of toner particles by salting out, aggregating and fusing the composite resin particles and the colorant particles Aggregating and fusing steps (II), (3) filtering and washing steps for removing toner particles from the toner particle dispersion and removing surfactants and the like from the toner particles, and (4) washing-treated toner A drying step of drying the particles, and (5) a step of adding an external additive to the dried toner particles.

Hereinafter, each step will be described. << Multi-stage polymerization step (I) >> In the multi-stage polymerization step (I), a composite is formed by a multi-stage polymerization method in which a coating layer (n + 1) made of a polymer of the monomer (n + 1) is formed on the surface of the resin particles (n). This is a step of producing resin particles. Where the stability of the production,
From the viewpoint of the crushing strength of the obtained toner, it is preferable to employ a multi-stage polymerization method of three-stage polymerization or more.

The two-stage polymerization method and the three-stage polymerization method, which are typical examples of the multi-stage polymerization method, will be described below.

<< Description of Two-Step Polymerization Method >> In the two-step polymerization method, a central part (nucleus) formed from a high molecular weight resin containing a release agent is used.
And a method of producing composite resin particles comprising an outer layer (shell) formed of a low molecular weight resin. That is, the composite resin particles obtained by the two-stage polymerization method are composed of a core and one coating layer.

The method will be described in detail. First, a monomer solution obtained by dissolving a releasing agent in a monomer (H) is dispersed in an aqueous medium (aqueous solution of a surfactant) by oil droplets. After that, this system is subjected to a polymerization treatment (first-stage polymerization), whereby
A dispersion of high molecular weight resin particles (H) containing a release agent is prepared.

Next, the dispersion of the resin particles (H) was added to
Polymerization initiator and monomer (L) for obtaining low molecular weight resin
Is added, and the monomer (L) is subjected to a polymerization treatment (second-stage polymerization) in the presence of the resin particles (H), whereby a low-molecular-weight resin (monomers) is formed on the surface of the resin particles (H). The coating layer (L) made of the polymer (L) is formed.

<< Description of Three-Step Polymerization Method >> In the three-step polymerization method, a central part (nucleus) formed of a high molecular weight resin, an intermediate layer containing a release agent, and an outer layer formed of a low molecular weight resin ( shell)
This is a method for producing composite resin particles composed of the following. That is, the composite resin particles obtained by the three-stage polymerization method are composed of a core and two coating layers.

The method will be described in detail. First, a dispersion of resin particles (H) obtained by a polymerization treatment (first-stage polymerization) according to a conventional method is mixed with an aqueous medium (aqueous solution of a surfactant). And a monomer solution obtained by dissolving a release agent in the monomer (M) is dispersed in the aqueous medium in oil droplets, and then the system is subjected to a polymerization treatment (second stage polymerization). Thereby, a coating layer (M) (intermediate layer) made of a resin (polymer of monomer (M)) containing a release agent is formed on the surface of the resin particles (H) (core particles). Of the composite resin particles [high molecular weight resin (H) -intermediate molecular weight resin (M)].

Next, a polymerization initiator and a monomer (L) for obtaining a low molecular weight resin are added to the obtained dispersion of the composite resin particles, and the monomer is added in the presence of the composite resin particles. By subjecting (L) to a polymerization treatment (third stage polymerization), a low molecular weight resin (monomer (L)
Is formed from the polymer (L).

In this three-stage polymerization method, the resin particles (H)
When the coating layer (M) is formed on the surface of the resin, the dispersion of the resin particles (H) is added to an aqueous medium (aqueous solution of a surfactant), and a single amount of a release agent is added to the aqueous medium. After the monomer solution obtained by dissolving the monomer (M) is dispersed in oil droplets, the system is subjected to a polymerization treatment (second stage polymerization), whereby the release agent is finely and uniformly dispersed. be able to.

Regarding the process of adding the dispersion of the resin particles (H) and the process of dispersing the monomer solution in oil droplets, any of the processes described below may be performed in advance or simultaneously. You may.

(A) When forming the intermediate layer constituting the composite resin particles, the resin particles to be the central part (nucleus) of the composite resin particles are added to an aqueous solution of a surfactant, and then the aqueous solution is added to the aqueous solution. An embodiment in which a monomer composition containing a release agent / crystalline polyester is dispersed and this system is polymerized. (B) When forming an intermediate layer constituting the composite resin particles, the release agent / crystallinity After dispersing a monomer composition containing a polyester in an aqueous solution of a surfactant, resin particles serving as a central portion (core) of the composite resin particles are added to the aqueous solution, and the system is subjected to polymerization treatment. Aspect, (c) When forming the intermediate layer constituting the composite resin particles, the resin particles serving as the central part (nucleus) of the composite resin particles are added to the aqueous solution of the surfactant,
A mode in which a monomer composition containing a release agent / crystalline polyester is dispersed in the aqueous solution and the system is subjected to polymerization treatment is included.

As a method for forming resin particles (core particles) or a coating layer (intermediate layer) containing a release agent, the release agent is dissolved in a monomer, and the resulting monomer solution is dissolved in an aqueous medium. And then subjecting the system to a polymerization treatment to obtain latex particles.

Here, "aqueous medium" refers to water 50 to 10
A medium consisting of 0% by mass and 0 to 50% by mass of a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran, and an alcohol-based organic solvent that does not dissolve the obtained resin is preferable.

As a polymerization method suitable for forming a resin particle or a coating layer containing a release agent, an aqueous medium obtained by dissolving a surfactant having a concentration equal to or lower than the critical micelle concentration is used.
A monomer solution obtained by dissolving a release agent in a monomer is dispersed in oil droplets using mechanical energy to prepare a dispersion, and a water-soluble polymerization initiator is added to the obtained dispersion. Then, a method of performing radical polymerization in an oil droplet (hereinafter, referred to as “mini-emulsion method”) can be exemplified. Instead of adding the water-soluble polymerization initiator, or together with the addition of the water-soluble polymerization initiator, an oil-soluble polymerization initiator may be added to the monomer solution.

According to the mini-emulsion method in which oil droplets are formed mechanically, unlike the usual emulsion polymerization method, the release agent dissolved in the oil phase is not released, and the resin particles or A sufficient amount of release agent can be introduced into the coating layer.

Here, the disperser for dispersing oil droplets by mechanical energy is not particularly limited, and a stirrer “CLEARMIX” (M Technic) equipped with a high-speed rotating rotor (Trade name), an ultrasonic disperser, a mechanical homogenizer, a Menton-Gaulin and a pressure homogenizer. Further, the dispersed particle diameter is 10 to 1
000 nm, preferably 50 to 1000 nm, more preferably 30 to 300 nm.

As a polymerization method for forming the resin particles containing the release agent or the coating layer, known methods such as an emulsion polymerization method, a suspension polymerization method, and a seed polymerization method may be employed. Further, these polymerization methods can also be employed to obtain resin particles (core particles) or coating layers constituting the composite resin particles, which do not contain a release agent and crystalline polyester.

The particle diameter of the composite resin particles obtained in the polymerization step (I) was determined by using an electrophoretic light scattering photometer “ELS-80”.
It is preferable that the weight average particle diameter measured using “0” (manufactured by Otsuka Electronics Co., Ltd.) is in the range of 10 to 1000 nm.

Also, the glass transition temperature (T
g) is preferably in the range of 48 to 74 ° C, more preferably 52 to 64 ° C. The softening point of the composite resin particles is preferably in the range of 95 to 140C.

<< Step of Salting Out, Aggregating and Fusing (II) >> The step of salting out, agglomerating and fusing (II) comprises the composite resin particles obtained by the multi-stage polymerization step (I) and the colorant particles. This is a step of obtaining amorphous (non-spherical) toner particles by salting out, aggregating, and fusing (simultaneously salting out and fusing).

In the step (II) of salting out, agglomeration and fusion, together with the composite resin particles and the colorant particles, internal additive particles such as a charge control agent (having a number average primary particle diameter of 10 to 1).
(Fine particles of about 000 nm) may be salted out, aggregated and fused.

The colorant particles may be surface-modified. Here, conventionally known surface modifiers can be used.

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

Here, the same surfactants as those used in the multi-stage polymerization step (I) can be used.

The disperser used for the dispersion treatment of the colorant particles is not particularly limited, but is preferably a stirrer “CLEARMIX (CLEARMI) equipped with a high-speed rotating rotor.
X) "(manufactured by M Technique Co., Ltd.), ultrasonic disperser,
Examples include a pressure disperser such as a mechanical homogenizer, a Manton-Gaulin, a pressure homogenizer, and a medium disperser such as a Getzman mill and a diamond fine mill.

In order to salt out, aggregate, and fuse the composite resin particles and the colorant particles, an aggregating agent having a critical aggregation concentration or more is added to the dispersion in which the composite resin particles and the colorant particles are dispersed. In addition, it is preferable to heat the dispersion to a temperature equal to or higher than the glass transition temperature (Tg) of the composite resin particles.

More preferably, a coagulation terminator is used when the composite resin particles reach a desired particle size by the coagulation agent. As the aggregation terminator, a monovalent metal salt, particularly, sodium chloride is preferably used.

The temperature range suitable for salting out, agglomeration and fusion is (Tg + 10) to (Tg + 50 ° C.), particularly preferably (Tg + 15) to (Tg + 40 ° C.).
It is said. Further, in order to effectively perform the fusion, an organic solvent which is infinitely soluble in water may be added.

As the "coagulant" used for salting out, coagulation and fusion, the above-mentioned alkali metal salts and alkaline earth metal salts can be mentioned.

The salting out and aggregation according to the present invention will be described. In the present invention, "salting out, coagulation, fusion" means
This refers to the simultaneous occurrence of salting out (aggregation of particles) and fusion (loss of the interface between particles), or the act of simultaneously causing salting out and fusion.

In order to carry out salting out and fusion simultaneously,
Glass transition temperature (Tg) of resin constituting composite resin particles
It is preferable that the particles (composite resin particles, colorant particles) are aggregated under the above temperature conditions.

The toner for developing an electrostatic image of the present invention forms composite resin particles in the absence of a colorant, and adds a dispersion of the colorant particles to the dispersion of the composite resin particles. It is preferably prepared by salting out, aggregating, and fusing the colorant particles.

As described above, by preparing the composite resin particles in a 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 fixing device is not stained or the image is not stained due to the accumulation of the toner.

In addition, as a result of the reliable polymerization reaction for obtaining the composite resin particles, no monomer or oligomer remains in the obtained toner particles, and the method for forming an image using the toner does not occur. No unpleasant odor is generated in the heat fixing step.

Further, the surface characteristics of the obtained toner particles are uniform and the charge amount distribution is sharp, so that an image having excellent sharpness can be formed for a long period of time. According to such a toner having a uniform composition, molecular weight, and surface characteristics among toner particles, good adhesion (high fixing strength) to an image support is maintained in an image forming method including a fixing step by a contact heating method. Meanwhile, the offset resistance and the anti-winding property can be improved, and an image having an appropriate gloss can be obtained.

The release agent used in the toner of the present invention will be described. The content ratio of the release agent constituting the toner for developing an electrostatic image of the present invention is usually 1 to 30% by mass, preferably 2 to 20% by mass, more preferably 3 to 1% by mass.
5% by mass.

As the release agent, low molecular weight polypropylene (number average molecular weight = 1500 to 9000), low molecular weight polyethylene or the like may be added, and a preferred release agent is an ester compound represented by the following general formula.

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 particularly preferably 4.

R ₁ and R ₂ each represent a hydrocarbon group which may have a substituent. R ₁ : carbon number = 1 to 40, preferably 1 to 20, more preferably 2 to 5 R ₂ : carbon number = 1 to 40, preferably 16 to 30, more preferably 18 to 26 or less, Specific examples of the ester compound represented by are shown below, but the present invention is not limited thereto.

[0118]

Embedded image

The release agent described above and the fixing improver represented by the general formula are added in an amount of from 1 to 30% by mass, preferably from 2 to 20% by mass, more preferably from 2 to 30% by mass of the whole toner for developing an electrostatic image. It is 3 to 15% by mass.

The preferred molecular weight, molecular weight range, peak molecular weight, and the like of the resin component constituting the toner for developing an electrostatic image of the present invention will be described.

The toner of the present invention has a peak or shoulder of 100,000 to 1,000,000, and 1,
Preferably, the peak or shoulder is between 100,000 and 1,000.
0000, 25,000-150,000, 1,
More preferably, it exists in the range of 000 to 50,000.

The molecular weight of the resin of the toner is 100,000.
A high molecular weight component having a peak or shoulder (shoulder) in the region of １，1,000,000,
Resins containing at least both low molecular weight components having peaks or shoulders in the region of less than 000 are preferred. More preferably, the peak molecular weight is 15,
The use of an intermediate molecular weight resin having a peak or shoulder in the range of 000 to 100,000.

The molecular weight is measured by using GPC (gel permeation chromatography) using THF (tetrahydrofuran) as a column solvent.

[0124] Specifically, the amount of T
HF is added in an amount of 1 ml, and the mixture is stirred at room temperature using a magnetic stirrer to be sufficiently dissolved. Then, after treating with a membrane filter having a pore size of 0.45 to 0.50 μm, the mixture is injected into GPC. The GPC measurement conditions were as follows: stabilize the column at 40 ° C., and set the THF to 1 m / min.
at a flow rate of 1 l / l and a sample at a concentration of 1 mg / ml
Inject μl and measure. As the column, it is preferable to use a commercially available polystyrene gel column in combination. For example, Shodex GPC manufactured by Showa Denko
KF-801, 802, 803, 804, 805, 80
6, 807 or TSKgelG1 manufactured by Tosoh Corporation
000H, G2000H, G3000H, G4000
H, G5000H, G6000H, G7000H, TS
Combinations of K guard columns can be mentioned.

As a detector, a refractive index detector (IR detector) or a UV detector is preferably used. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve created using monodispersed polystyrene standard particles. It is preferable to use about 10 polystyrenes for preparing a calibration curve.

The filtration and washing steps of the production of the toner for developing an electrostatic image of the present invention will be described.

In this filtration / washing step, a filtration treatment for filtering the toner particles from the dispersion system of the toner particles obtained in the above-described step, and the filtered toner particles (cake-like aggregate)
And a washing treatment for removing extraneous matter such as a surfactant and a flocculant from the surface.

Here, the filtration method is not particularly limited, such as a centrifugal separation method, a reduced pressure filtration method using a Nutsche method, a filtration method using a filter press or the like.

<< Drying Step >> This step is a step of drying the washed toner particles.

[0130] Examples of the drier used in this step include a spray drier, a vacuum freeze drier, a reduced pressure drier and the like, and a stationary shelf drier, a mobile shelf drier, a fluidized bed drier, a rotary drier. It is preferable to use a type dryer, a stirring type dryer and the like.

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

When the dried toner particles are agglomerated by weak attraction between the particles, the agglomerates may be crushed. Here, as the crushing device, a mechanical crushing device such as a jet mill, a Henschel mixer, a coffee mill, and a food processor can be used.

The polymerizable monomer according to the present invention will be described. (1) Hydrophobic monomer The hydrophobic monomer constituting the monomer component is not particularly limited, and a conventionally known monomer can be used. In addition, one kind or a combination of two or more kinds can be used so as to satisfy required characteristics.

Specifically, a monovinyl aromatic monomer,
It is possible to use (meth) acrylate monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers, halogenated olefin monomers, and the like. it can.

Examples of the vinyl aromatic monomer 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- Styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

The acrylic monomers include acrylic acid,
Methacrylic acid, methyl acrylate, ethyl acrylate,
Butyl acrylate, 2-ethylhexyl acrylate,
Cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, methacryl Dimethylaminoethyl acrylate, diethylaminoethyl methacrylate and the like.

Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl benzoate and the like.

Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

Examples of the monoolefin-based monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.

(2) Crosslinkable monomer A crosslinkable monomer may be added in order to improve the properties of the resin particles. As crosslinkable monomers, divinylbenzene,
Divinyl naphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate,
Those having two or more unsaturated bonds such as diallyl phthalate are exemplified.

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

Examples of the α, β-ethylenically unsaturated compound (a) having a —COO group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, and monobutyl maleate. Examples thereof include esters, monooctyl maleate, and metal salts of Na, Zn and the like.

(B) Examples of α, β-ethylenically unsaturated compounds having a sulfo group (—SO ₃ H group) include sulfonated styrene, its Na salt, allyl sulfosuccinic acid, allyl sulfosuccinate octyl, its Na salt And the like.

The initiator (also referred to as a polymerization initiator) used in the polymerization of the polymerizable monomer according to the present invention will be described.

The polymerization initiator used in the present invention can be appropriately used as long as it is water-soluble. For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4'-azobis-4-cyanovaleric acid and salts thereof,
2,2'-azobis (2-amidinopropane) salt and the like),
Peroxide compounds such as hydrogen peroxide and benzoyl peroxide are included.

Further, the above polymerization initiator can be used as a redox initiator in combination with a reducing agent, if necessary. By using a redox-based initiator, the polymerization activity is increased, the polymerization temperature can be reduced, and a further reduction in the polymerization time can be expected.

As the polymerization temperature, any temperature may be selected as long as it is equal to or higher than the minimum radical generation temperature of the polymerization initiator. For example, a temperature in the range of 50 ° C. to 80 ° C. is used. Also, by using a polymerization initiator which starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (such as ascorbic acid), it is possible to perform polymerization at room temperature or a temperature close thereto.

The chain transfer agent used in the present invention will be described. In the present invention, for the purpose of adjusting the molecular weight of the resin particles produced by polymerization of the polymerizable monomer,
It is possible to use a conventionally known generally used chain transfer agent.

The chain transfer agent is not particularly limited. In particular, a compound having a mercapto group is preferably used because a toner having a sharp molecular weight distribution can be obtained and the storage stability, fixing strength, and offset resistance are excellent. For example, octyl mercaptan, dodecyl mercaptan, t
A compound having a mercapto group such as ert-dodecyl mercaptan is used.

Preferred are, for example, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate,
2-ethylhexyl thioglycolate, octyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, thioglycolic acid ester of ethylene glycol, thioglycolic acid ester of neopentyl glycol, thioglycolic acid ester of pentaerythritol, etc. Can be done.

Among them, n-octyl-3-mercaptopropionate is preferably used from the viewpoint of suppressing the odor during the heating and fixing of the toner.

The colorant according to the present invention will be described. The colorant according to the toner for developing an electrostatic image of the present invention is used for salting out, agglomeration, and fusion of the above-described composite resin particles together with the resin particles during toner production, from the viewpoint of improving the uniformity of charging of the toner. , Agglomerated, fused and contained in the toner particles.

Examples of the colorant (colorant particles subjected to salting out, aggregation, and fusion with the composite resin particles) constituting the toner of the present invention include various inorganic pigments, organic pigments, and dyes. . Conventionally known inorganic pigments 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. The amount of the pigment to be 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 predetermined magnetic characteristics, 20 to 1
It is preferable to add 20% by mass.

Conventionally known organic pigments and dyes can also be used. Specific examples of organic pigments and dyes are shown below.

The pigments for magenta or red include:
C. 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. I. Pigment Red 15, C.I. I. Pigment Red 16,
C. 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. Pigment red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I.
I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222 and the like.

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. 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 94, C.I. I.
Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 185, C.I.
I. Pigment yellow 155, C.I. I. Pigment Yellow 156 and the like.

Examples of green or cyan pigments include:
C. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3,
C. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111,
122, C.I. I. Solvent Yellow 19, 44
77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93
95 and the like, and mixtures thereof can also be used.

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

The colorant (colorant particles) constituting the electrostatic image developing toner of the present invention may be surface-modified.
Here, conventionally known surface modifiers can be used, and specifically, silane coupling agents, titanium coupling agents, aluminum coupling agents, 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, vinyl Trichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
γ-ureidopropyltriethoxysilane and the like.

As the titanium coupling agent, for example,
TTS, 9S, 38S, 41B, 46B, 5B, which are commercially available under the trade name "Plenact" manufactured by Ajinomoto Co.
5, 138S, 238S, etc., commercial products A-
1, B-1, TOT, TST, TAA, TAT, TL
A, TOG, TBSTA, A-10, TBT, B-2,
B-4, B-7, B-10, TBSTA-400, TT
S, TOA-30, TSDMA, TTAB, TTOP and the like.

[0167] Examples of the aluminum coupling agent include "Plenact AL-M" manufactured by Ajinomoto Co. and the like.

The addition amount of these surface modifiers is preferably from 0.01 to 20% by mass, more preferably from 0.1 to 5% by mass, based on the colorant.

Examples of the method for modifying the surface of the colorant particles include a method in which a surface modifier is added to a dispersion of the colorant particles, and the system is heated and reacted.

[0170] The surface-modified colorant particles are collected by filtration, and are dried after repeated washing and filtration with the same solvent.

The toner particles constituting the toner of the present invention may contain an internal additive other than the release agent, such as a charge control agent.

Examples of the charge control agent contained in the toner particles include a nigrosine dye, a metal salt of naphthenic acid or a higher fatty acid, an alkoxylated amine, a quaternary ammonium salt compound, an azo metal complex, a metal salt of salicylic acid or a salt thereof. Metal complexes and the like.

The external additives used in the toner of the present invention will be described. As the inorganic fine particles that can be used as the external additive, conventionally known inorganic fine particles can be exemplified. Specifically, silica fine particles, titanium fine particles, alumina fine particles and the like can be preferably used. These inorganic fine particles are preferably hydrophobic.

Specific examples of the silica fine particles include commercially available products R-805, R-976, and R-980 manufactured by Nippon Aerosil Co., Ltd.
974, R-972, R-812, R-809, HVK-2150 and H-200 manufactured by Hoechst Co., Ltd., and commercial products TS-720, TS-530, TS manufactured by Cabot Co., Ltd.
-610, H-5, MS-5 and the like.

Specific examples of the titanium fine particles include, for example,
Commercial products T-805 and T-60 manufactured by Nippon Aerosil Co., Ltd.
4. Commercial products MT-100S and MT-1 manufactured by Teika Co., Ltd.
00B, MT-500BS, MT-600, MT-60
0SS, JA-1, commercial product TA- manufactured by Fuji Titanium Co., Ltd.
300SI, TA-500, TAF-130, TAF-
510, TAF-510T, and commercial products IT-S, IT-OA, IT-OB, IT-OC manufactured by Idemitsu Kosan Co., Ltd.

Specific examples of the alumina fine particles include, for example, commercially available products RFY-C and C-C manufactured by Nippon Aerosil Co., Ltd.
604, a commercial product TTO-55 manufactured by Ishihara Sangyo Co., Ltd., and the like.

Examples of the organic fine particles that can be used as an external additive include spherical fine particles having a number average primary particle diameter of about 10 to 2000 nm. Examples of the constituent material of the organic fine particles include polystyrene, polymethyl methacrylate, and styrene-methyl methacrylate copolymer.

Examples of the lubricant that can be used as an external additive include metal salts of higher fatty acids. Specific examples of such metal salts of higher fatty acids include metal stearate salts such as zinc stearate, aluminum stearate, copper stearate, magnesium stearate, and calcium stearate; zinc oleate, manganese oleate, iron oleate, and olein. Metal salts of oleic acid such as copper phosphate and magnesium oleate; Metal salts of palmitic acid such as zinc palmitate, copper palmitate, magnesium palmitate and calcium palmitate; Metal salts of linoleic acid such as zinc linoleate and calcium linoleate; Ricinol And metal salts of ricinoleic acid such as zinc acid and calcium ricinoleate.

The addition amount of the external additive is preferably about 0.1 to 5% by mass based on the toner.

The step of adding the external additive will be described. This step is a step of adding an external additive to the dried toner particles.

Examples of the apparatus used for adding the external additive include a turbulent mixer, a Hensiel mixer,
Various known mixing devices such as a Nauta mixer and a V-type mixer can be used.

The particle size of the toner for developing an electrostatic image of the present invention will be described. The particle diameter of the toner of the present invention is preferably 3 to 10 μm, more preferably 3 to 8 μm in number average particle diameter. This particle diameter can be controlled by the concentration of the coagulant, the amount of the organic solvent added, the fusing time, and the composition of the polymer in the method for producing a toner described in detail below.

When the number average particle diameter is from 3 to 10 μm, in the fixing step, the number of toner particles having a large adhesive force which flies and adheres to the heating member to generate an offset is reduced, and the transfer efficiency is increased. The halftone image quality is improved, and the image quality of fine lines and dots is improved.

The number-average particle diameter of the toner is determined by using Coulter Counter TA-II, Coulter Multisizer, SLAD
It can be measured using 1100 (a laser diffraction particle size analyzer manufactured by Shimadzu Corporation) or the like.

In the present invention, a Coulter Multisizer was used, and an interface for outputting a particle size distribution (manufactured by Nikkaki) and a personal computer were connected. The particle size distribution and the average particle size were calculated by measuring the volume distribution of toner having a size of 2 μm or more (for example, 2 to 40 μm) using an aperture of 100 μm in the Coulter Multisizer.

The shape coefficient of the toner particles of the present invention will be described. The shape factor of the toner of the present invention is represented by the following equation, and indicates the degree of roundness of toner particles.

Shape factor = ((maximum diameter / 2) ² × π) / projected area Here, the maximum diameter is defined as a parallel line when a projected image of a toner particle on a plane is sandwiched between two parallel lines. Means the width of the particle at which the distance between the particles becomes maximum. The projection area refers to the area of the projected image of the toner particles on the plane.

In the present invention, the shape factor is determined by taking a photograph in which the toner particles are magnified 2000 times with a scanning electron microscope, and referring to the “SCCANNING” based on the photograph.
The measurement was performed by analyzing a photographic image using "IMAGE ANALYZER" (manufactured by JEOL Ltd.). In this case, the shape factor of the present invention was measured by using the above formula using 100 toner particles.

In the above constitutions (1) and (9), the number of toner particles having a shape factor in the range of 1.0 to 1.6 is preferably at least 65% by number, more preferably at least 70%. % Or more. More preferably, the number of toner particles whose shape factor is in the range of 1.2 to 1.6 is 65% by number or more, and more preferably, 7%.
0% by number or more.

When the number of toner particles having a shape coefficient in the range of 1.0 to 1.6 is 65% by number or more, the triboelectrification property in the developer conveying member or the like becomes more uniform, and the excessively charged toner Is not accumulated, and the toner is more easily exchanged than the surface of the developer conveying member. Therefore, problems such as a development ghost are less likely to occur. Further, the toner particles are less likely to be crushed, so that the contamination of the charging member is reduced, and the charging property of the toner is stabilized.

In the configuration (16), 65% by number or more of the toner particles having the shape factor in the range of 1.2 to 1.6 is required.
70% by number or more.

The method of controlling the shape factor is not particularly limited. For example, a method of spraying toner particles in a hot air flow, a method of repeatedly applying mechanical energy by an impact force in a gas phase, or a method of adding a toner particle in a solvent that does not dissolve a toner to impart a swirling flow, etc. To prepare a toner having a shape factor of 1.0 to 1.6 or 1.2 to 1.6, and then add it to a normal toner so as to fall within the range of the present invention. There is. Further, the overall shape is controlled at the stage of adjusting the so-called polymerization toner, and the shape factor is set to 1.0 to 1.6,
Alternatively, there is a method in which the toner adjusted to 1.2 to 1.6 is similarly added to an ordinary toner to adjust.

In the toner of the present invention, when the particle diameter of the toner particles is D (μm), the natural logarithm InD 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 particle size distribution, the sum (M1) of the relative frequency (m1) of the toner particles included in the most frequent class and the relative frequency (m2) of the toner particles included in the class having the second highest frequency after the most frequent class. ) Is preferably 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 is narrowed. Thus, the occurrence of selective development can be reliably suppressed.

In the present invention, the histogram showing the number-based particle size distribution is obtained by plotting a natural logarithm lnD (D: particle size of individual toner particles) 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 to 2.07: 2.07 to 2.30: 2.30 to
2.53: 2.53 to 2.76...) Is a histogram showing the number-based particle size distribution, which is a particle size data of a sample measured by a Coulter Multisizer according to the following conditions. Is transferred to a computer via an I / O unit, and the computer creates the program using a particle size distribution analysis program.

<< Measurement Conditions >> (1) Aperture: 100 μm (2) Sample Preparation Method: Electrolyte [ISOTON R-1
1 (manufactured by Coulter Scientific Japan)
An appropriate amount of a surfactant (neutral detergent) is added to 50 to 100 ml, and the mixture is stirred, and 10 to 20 mg of a measurement sample is added thereto. This system is prepared by subjecting it to a dispersion treatment with an ultrasonic disperser for 1 minute.

The “cornerless toner particles” according to the present invention will be described with reference to FIG. In the toner according to the present invention, the ratio of the toner particles having no corners in the toner particles constituting the toner is preferably 50% by number or more, more preferably 70% by number or more.

When the ratio of the toner particles having no corners is 50% by number or more, the gap of the transferred toner layer (powder layer) is reduced, the fixing property is improved, and the offset hardly occurs. In addition, the amount of toner particles that are easily worn or broken and the number of toner particles having a portion where charges are concentrated are reduced, the charge amount distribution is sharpened, the chargeability is stabilized, and good image quality can be formed over a long period of time.

Here, "toner particles having no corners" refers to toner particles having substantially no protrusions on which electric charges are concentrated or which are easily worn by stress.
Specifically, the following toner particles are referred to as toner particles having no corners. That is, as shown in FIG.
When the major axis is L, a circle C having a radius (L / 10)
The case where the circle C does not substantially protrude outside the toner T when the inside is rolled while contacting the inside at one point with respect to the peripheral line of the toner particle T is referred to as “toner particle having no corner”. “Cases that do not substantially protrude” refer to cases where there are no more than one protrusion having a protruding circle. Also,
The “longer diameter of the toner particle” refers to the width of the particle at which the interval between the parallel lines is the largest when the projected image of the toner particle on the plane is sandwiched between two parallel lines. FIGS. 1B and 1C show projected images of the toner particles having corners, respectively.

The ratio of the toner particles having no corners was measured as follows. First, a photograph in which the toner particles were enlarged by a scanning electron microscope was taken, and further enlarged to 15.0.
Obtain a 00x photographic image. Next, the presence or absence of the corners is measured for this photographic image. This measurement was performed for 100 toner particles.

The method for obtaining a toner having no corners is not particularly limited. For example, as described above, as a method of controlling the shape coefficient, a method of spraying toner particles into a hot air flow, a method of repeatedly applying mechanical energy by an impact force in a gas phase, or a method of dissolving a toner It can be obtained by adding to a solvent that does not contain and giving a swirling flow.

The developer used in the present invention will be described. The toner of the present invention may be used as a one-component developer or a two-component developer.

When used as a one-component developer, a non-magnetic one-component developer or 0.1 to 0.5 μm
And a magnetic one-component developer containing a certain amount of magnetic particles, and any of them can be used.

Further, it can be used as a two-component developer by mixing with a carrier. In this case, as magnetic particles of the carrier, metals such as iron, ferrite and magnetite,
Conventionally known materials such as alloys of these metals with metals such as aluminum and lead can be used. Particularly, ferrite particles are preferable. The magnetic particles have a volume average particle size of 15 to 100 μm, more preferably 25 to 8 μm.
It is preferably 0 μm.

The volume average particle size of the carrier is typically measured by a laser diffraction type particle size distribution analyzer “HELOS” equipped with a wet disperser (SYMPATIC (SYMPIC)
(ATEC)).

The carrier is preferably a carrier in which magnetic particles are further coated with a resin, or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, but, for example, an olefin resin, a styrene resin, a styrene-acrylic resin, a silicone resin, an ester resin, or a fluorine-containing polymer resin is used. The resin for forming the resin dispersion type carrier is not particularly limited, and a known resin can be used. For example, a styrene-acrylic resin, a polyester resin, a fluororesin, a phenol resin, or the like is used. be able to.

The image forming method of the present invention will be described.
The toner of the present invention includes an image forming method including a step of fixing an image forming support on which a toner image is formed by passing the support between a heating roller and a pressure roller constituting a fixing device (the image forming method of the present invention). Method).

FIG. 2 is a cross-sectional view showing an example of a fixing device used in the image forming method of the present invention. The fixing device shown in FIG. 2 includes a heating roller 10 and a pressure roller 20 in contact therewith. Have. In FIG. 2, T
Is a toner image formed on a transfer paper (image forming support).

The heating roller 10 has a coating layer 12 made of a fluororesin or an elastic body formed on the surface of a core metal 11 and includes a heating member 13 made of a linear heater.

The core metal 11 is made of metal and has an inner diameter of 10 to 70 mm. The metal constituting the metal core 11 is not particularly limited, but examples thereof include metals such as iron, aluminum and copper or alloys thereof.

The thickness of the core metal 11 is set to 0.1 to 15 mm, and is determined in consideration of a balance between a demand for energy saving (thinning) and a strength (depending on a constituent material). For example,
In order to maintain a strength equivalent to that of a 0.57 mm iron core with an aluminum core, the wall thickness must be 0.8 mm.

As the fluororesin constituting the coating layer 12, PTFE (polytetrafluoroethylene) and P
FA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) and the like can be exemplified.

The coating layer 12 made of a fluororesin has a thickness of 1
It is 0-500 μm, preferably 20-400 μm.

When the thickness of the coating layer 12 made of fluororesin is 1
When the thickness is less than 0 μm, the function as a coating layer cannot be sufficiently exhibited, and the durability as a fixing device cannot be secured. On the other hand, there is a problem that the surface of the coating layer having a thickness of more than 500 μm is easily scratched by paper dust, and toner or the like adheres to the scratched portion, thereby causing image stains.

[0215] As the elastic body constituting the coating layer 12, it is preferable to use silicone rubber and silicone sponge rubber having good heat resistance, such as LTV, RTV, and HTV.

Elastic Asker C constituting the coating layer 12
The hardness is less than 80 °, preferably less than 60 °.

The thickness of the coating layer 12 made of an elastic material is 0.1 to 30 mm, preferably 0.1 to 20 mm.
It is said.

Elastic Asker C constituting the coating layer 12
When the hardness exceeds 80 ° and when the thickness of the coating layer 12 is less than 0.1 mm, the nip for fixing cannot be increased, and the effect of soft fixing (for example, the smoothed interface Improvement effect of color reproducibility by toner layer)
Cannot be demonstrated.

[0219] As the heating member 13, a halogen heater can be suitably used. The pressure roller 20
A coating layer 22 made of an elastic body is formed on the surface of the core metal 21. The elastic body constituting the coating layer 22 is not particularly limited, and examples thereof include various soft rubbers such as urethane rubber and silicone rubber and sponge rubber, and the silicone rubber exemplified as the material constituting the coating layer 12 and the like. It is preferable to use silicone sponge rubber.

Elastic Asker C constituting the coating layer 22
The hardness is less than 80 °, preferably less than 70 °, more preferably less than 60 °.

The thickness of the coating layer 22 is 0.1 to 30 m.
m, and preferably 0.1 to 20 mm.

Elastic Asker C constituting the coating layer 22
When the hardness exceeds 80 ° and when the thickness of the coating layer 22 is less than 0.1 mm, the nip for fixing cannot be increased, and the effect of soft fixing cannot be exhibited.

The material constituting the core metal 21 is not particularly limited, but examples thereof include metals such as aluminum, iron, and copper, and alloys thereof.

The contact load (total load) between the heating roller 10 and the pressure roller 20 is usually 40 to 350 N, preferably 50 to 300 N, more preferably 50 to 300 N.
２５０250N. This contact load is applied to the heating roller 1
It is defined in consideration of the strength of 0 (the thickness of the core 11). For example, in a heating roller having a core of 0.3 mm made of iron, the heating roller is preferably set to 250 N or less.

Further, from the viewpoint of offset resistance and fixability, the nip width is preferably 4 to 10 mm, and the surface pressure of the nip is 0.6 × 105 Pa to 1.5 mm.
It is preferably 105 Pa.

An example of the fixing condition by the fixing device shown in FIG. 2 is as follows. Fixing temperature (surface temperature of heating roller 10)
Is 150 to 210 ° C., and the fixing linear velocity is 80 to 640 m.
m / sec.

The fixing device used in the present invention may be provided with a cleaning mechanism as needed. In this case, as a method of supplying the silicone oil to the upper roller (heating roller) of the fixing unit, a method of supplying and cleaning with a pad, a roller, a web, or the like impregnated with the silicone oil can be used.

As the silicone oil, those having high heat resistance are used, and polydimethyl silicone, polyphenylmethyl silicone, polydiphenyl silicone and the like are used. Since those having a low viscosity have a large outflow during use, those having a viscosity at 20 ° C. of 1 to 100 Pa · s are preferably used.

However, the effect of the present invention is particularly remarkably exhibited when an image is formed by a fixing device in which silicone oil is not supplied or a supply amount of silicone oil is extremely low. Therefore, even when supplying silicone oil, the supply amount is 2 mg.
/ A4 or less.

The supply amount of silicone oil was 2 mg / A4
Transfer paper after fixing (image support)
The amount of silicone oil adhering to the transfer paper is reduced, and there is no difficulty in writing an oil-based pen such as a ballpoint pen with the silicone oil adhering to the transfer paper, and the writing performance is not impaired.

Further, it is possible to avoid problems such as deterioration of the anti-offset property with time due to deterioration of the silicone oil, and contamination of the optical system and the band electrode by the silicone oil.

Here, the supply amount of the silicone oil is determined by transferring the transfer paper (A) to a fixing device (between rollers) heated to a predetermined temperature.
100 sheets of 4 size white paper) are continuously passed, and the mass change (Δw) of the fixing device before and after the paper passing is measured and calculated (Δw / 100).

[0233]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

<< Preparation of Latex >> (Preparation of Latex 1HML) (1) Preparation of Latex (1H) (Formation of Core Particles;
Step polymerization) In a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introducing device, 7.08 was added.
g of the compound (101) in 3010 g of ion-exchanged water was charged with a surfactant solution (aqueous medium), and the mixture was stirred at a stirring speed of 230 rpm under a nitrogen stream, and the internal temperature was raised to 80.
The temperature was raised to ° C.

To this surfactant solution was added 9.2 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water.
Was added and the temperature was adjusted to 75 ° C., and then a monomer mixture A comprising 70.1 g of styrene, 19.9 g of n-butyl acrylate, and 10.9 g of methacrylic acid was added to 1 Polymerization (first-stage polymerization) was carried out by dropwise addition over a period of time and heating and stirring at 75 ° C. for 2 hours to prepare a latex (a dispersion of resin particles composed of a high molecular weight resin). This is designated as latex (1H).

(2) Preparation of Latex (1HM) (Formation of Intermediate Layer: Second Stage Polymerization) In a flask equipped with a stirrer, 105.6.
g styrene, 30.0 g n-butyl acrylate,
6.4 g methacrylic acid, 5.6 g n-octyl-3
-To a monomer mixture comprising mercaptopropionate, 72.0 g of the ester compound (19) was added,
The mixture was heated to 80 ° C. and dissolved to prepare a monomer solution B.

On the other hand, 1.6 g of compound (101) was added to 27
A surfactant solution dissolved in 00 ml of ion-exchanged water was heated to 80 ° C., and 28 g of the latex (1H) was added to the surfactant solution in terms of solid content. Machine "CLEARMIX (CLEAR
MIX) "(manufactured by M Technique Co., Ltd.) to mix and disperse the monomer solution B to obtain a uniform dispersed particle diameter (284 n).
(Emulsion liquid) containing emulsified particles (oil droplets) having m)
Was prepared.

Next, 5.1 parts of this dispersion (emulsion) was added.
g of polymerization initiator (KPS: potassium persulfate)
1 m of an initiator solution dissolved in 1 deionized water,
(2nd stage polymerization) by adding 1 l of ion-exchanged water and heating and stirring the system at 80 ° C. for 3 hours.
To obtain a latex (a dispersion of composite resin particles having a structure in which the surfaces of resin particles made of a high molecular weight resin are coated with an intermediate molecular weight resin). This is latex (1HM)
And

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

The composite resin particles constituting the latex (1HML) are 138,000, 80,000 and 13,000.
The composite resin particles had a peak molecular weight of 000, and the weight average particle size of the composite resin particles was 122 nm.

(Preparation of latex 2HML) Latex (high molecular weight resin) was prepared in the same manner as in the preparation of latex 1HML except that 7.08 g of sodium dodecyl sulfonate (SDS) was used in place of compound (101). , An intermediate layer made of an intermediate molecular weight resin, and an outer layer made of a low molecular weight resin). This latex is referred to as “latex (2HML)”.

The composite resin particles constituting the latex (2HML) are 138,000, 80,000 and 12,
It had a peak molecular weight of 000, and the composite resin particles had a weight average particle size of 110 nm.

<< Production Example of Toner >> (Preparation of Toner Particle 1) 59.0 g of Compound (101)
Was stirred and dissolved in 1600 ml of ion-exchanged water. While stirring this solution, carbon black “Legal 33”
0 "(manufactured by Cabot Corporation) 420.0 g,
Next, "Clear Mix" (M Technique Co., Ltd.)
To prepare a dispersion 1 of colorant particles (hereinafter referred to as “colorant dispersion 1”).

The particle size of the colorant particles in this colorant dispersion 1 was measured by using an electrophoretic light scattering photometer “ELS-800”.
It was 98 nm in weight average particle diameter when measured using (manufactured by Otsuka Electronics Co., Ltd.).

A reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introduction device, and a stirrer was charged with 420.7 g (in terms of solid content) of latex 1HML, 900 g of ion-exchanged water, and 166 g of a colorant dispersion 1. (Four-neck flask)
And stirred. After adjusting the internal temperature to 30 ° C., a 5N aqueous sodium hydroxide solution was added to the solution to adjust the pH to 11.1.
Adjusted to zero.

Subsequently, magnesium chloride hexahydrate12.
An aqueous solution obtained by dissolving 1 g in 1000 ml of ion-exchanged water,
The solution was added at 30 ° C. over 10 minutes with stirring. After standing for 3 minutes, heating was started, and the system was heated to 90 ° C. for 6 minutes.
(The temperature was raised at a rate of 10 ° C./min.). In that state,
The particle size of the associated particles was measured with a “Coulter counter TA-II”, and when the number average particle size became 5.5 μm,
80.4 g of sodium chloride in 1000 ml of ion-exchanged water
Was added thereto to stop the growth of particles, and as an aging treatment, the mixture was heated and stirred at a liquid temperature of 85 ° C. for 2 hours to continue the fusion. Then 8 ° C
The mixture was cooled to 40 ° C under the conditions of / min, the pH was adjusted to 2.0 by adding hydrochloric acid, and the stirring was stopped. The generated associated particles are filtered, washed repeatedly with ion-exchanged water whose temperature has been adjusted to 45 ° C, and then dried with warm air at 40 ° C.
Colored particles having a number average particle size of 5.7 μm were obtained. The obtained colored particles are referred to as “toner particles 1”. The residual amount of the surfactant in “Toner Particle 1” was 28 ppm, and the residual magnesium amount introduced from the flocculant was 4500 ppm.

(Preparation of Toner Particle 2) Compound (101)
In the same manner as in the production of the toner particles 1 except that 59.0 g of the following compound (102) was used in place of the above, colored particles having a number average particle diameter of 5.7 μm were obtained. The obtained colored particles are referred to as “toner particles 2”. The residual amount of the surfactant in “Toner Particle 2” was 32 ppm, and the residual magnesium amount introduced from the flocculant was 3600 ppm.

(Preparation of Toner Particle 3) Compound (101)
Was replaced with 59.0 g of the following compound (103), and colored particles having a number average particle size of 5.8 μm were obtained in the same manner as in the preparation of toner particles 2. The obtained colored particles are referred to as “toner particles 3”. The residual amount of the surfactant in “Toner Particle 3” was 48 ppm, and the residual magnesium amount introduced from the flocculant was 8870 ppm.

(Preparation of Toner Particles 4) Compound (101)
In the same manner as in the preparation of the toner particles 1 except that 59.0 g of the following compound (104) was used instead of the above, colored particles having a number average particle diameter of 5.8 μm were obtained. The obtained colored particles are referred to as “toner particles 4”. The residual amount of the surfactant in “Toner Particle 4” was 53 ppm, and the residual magnesium amount introduced from the flocculant was 7,960 ppm.

(Preparation of Toner Particle 5) Compound (101)
Was replaced with 59.0 g of the following compound (105) to obtain colored particles having a number average particle size of 5.8 μm in the same manner as in the preparation of toner particles 1. The obtained colored particles are referred to as “toner particles 5”. The residual amount of the surfactant in the “toner particles 5” was 84 ppm, and the residual magnesium amount introduced from the coagulant was 5050 ppm.

(Preparation of Toner Particle 6) Compound (101)
Was replaced with 59.0 g of the following compound (106), and colored particles having a number average particle diameter of 5.7 μm were obtained in the same manner as in the preparation of toner particles 1. The obtained colored particles are referred to as “toner particles 6”. The residual amount of the surfactant of “toner particles 6” was 91 ppm, and the residual magnesium amount introduced from the coagulant was 5050 ppm.

(Preparation of Toner Particle 7) Calcium chloride 18.2 instead of 12.1 g of magnesium chloride hexahydrate
g, except that g was used.
Colored particles having a number average particle size of 5.8 μm were obtained. The obtained colored particles are referred to as “toner particles 7”. The residual amount of the surfactant of “toner particles 7” was 26 ppm, and the residual calcium amount introduced from the flocculant was 8500 ppm.

(Preparation of Toner Particle 8) Aluminum chloride 4.1 instead of magnesium chloride hexahydrate 12.1 g
g, except that g was used.
Colored particles having a number average particle size of 5.7 μm were obtained. The obtained colored particles are referred to as “toner particles 8”. The residual amount of the surfactant of “toner particles 8” was 76 ppm, and the residual aluminum amount introduced from the flocculant was 16000 ppm.

(Preparation of Toner Particles 9) The same procedure as in the preparation of toner particles 1 was carried out except that the washing temperature was changed from 40 ° C. to 47 ° C., washed with ion-exchanged water, and then washed with ethanol.
Colored particles having a number average particle size of 5.7 μm were obtained. The obtained colored particles are referred to as “toner particles 9”. The residual amount of the surfactant of “toner particles 9” was 2 ppm, and the residual magnesium amount introduced from the coagulant was 264 ppm.

(Preparation of Toner Particles 10) Cleaning Temperature 40 ° C.
Was adjusted to 36 ° C., and colored particles having a number average particle size of 5.7 μm were obtained in the same manner as in the preparation of the toner particles 1 except that the washing water was reduced. The obtained colored particles are referred to as “toner particles 10”. The remaining amount of the surfactant in the “toner particles 10” is 1000
ppm, the amount of residual magnesium introduced from the flocculant is 2
It was 4000 ppm.

(Preparation of Toner Particles 11) Latex 1H
Except that latex 2HML was used instead of ML, the number average particle diameter was 5.7 μm in the same manner as in the preparation of toner particles 1.
Colored particles were obtained. The obtained colored particles are referred to as “toner particles 1”.
1 ". The residual amount of the surfactant of the “toner particles 11” was 36 ppm, and the residual magnesium amount introduced from the flocculant was 4000 ppm.

(Preparation of Toner Particles 1 for Comparison) The number average particle diameter was the same as in the preparation of toner particles 1 except that latex 2HML was used instead of latex 1HML and sodium dodecyl sulfate was used to disperse the colored particles. 5.7
μm colored particles were obtained. The obtained colored particles are referred to as “comparative toner particles 1”. The amount of residual surfactant in “Comparative Toner Particle 1” was 38 ppm, and the amount of residual magnesium introduced from the aggregating agent was 6500 ppm.

(Preparation of Comparative Toner Particle 2) Compound (1)
Colored particles having a number average particle size of 5.7 μm were obtained in the same manner as in the preparation of the toner particles 1 except that 59.0 g of the following compound (107) was used instead of (01). The obtained colored particles are referred to as “comparative toner particles 2”. The surfactant amount of “Comparative Toner Particle 2” was 530 ppm, and the residual magnesium amount introduced from the coagulant was 8400 ppm.

Compound (107): C ₁₂ H ₂₅ (O (C
H ₂ ) ₁₀ ) ₂ OSO ₃ Na (Preparation of Comparative Toner Particle 3) In the same manner as in preparation of toner particle 1, except that 59.0 g of compound (108) was used instead of compound (101), 5.7 μm diameter
Colored particles were obtained. The obtained colored particles are referred to as “comparative toner particles 3”. The surfactant amount of “Comparative Toner Particle 3” was 48 ppm, and the residual magnesium amount introduced from the coagulant was 6340 ppm.

Compound (108): C ₁₀ H ₂₁ (OCH ₂ C
H ₂ ) ₁₂ OSO ₃ Na (Preparation of Comparative Toner Particles 4) In the same manner as in the preparation of toner particles 1, except that 59.0 g of compound (109) was used instead of compound (101), the number average particle diameter was 5 0.7 μm
Colored particles were obtained. The obtained colored particles are referred to as “comparative toner particles 4”. The residual amount of the surfactant in “Comparative Toner Particles 4” was 46 ppm, and the residual magnesium amount introduced from the flocculant was 8050 ppm.

Compound (109): C ₂₈ H ₅₇ (OCH ₂ C
H ₂ ) ₂ OSO ₃ Na Physical properties and chemical properties of the obtained toner particles are shown in Table 1.
It is shown in Table 2.

[0262]

[Table 1]

[0263]

[Table 2]

The toner particles 1 obtained as described above
11. To each of the comparative toners 1 to 4, hydrophobic silica (number average primary particle diameter 10 nm, hydrophobicity 63) was added at a ratio of 1.0% by mass, and hydrophobic titanium oxide (number average primary particle) was added. Particle diameter 25 nm, hydrophobicity 60) 1.2
Each was added at a ratio of mass%, and mixed with a Henschel mixer.

The shape and particle size of these toner particles are not changed by the addition of hydrophobic silica and hydrophobic titanium oxide.

Each of the toner particles to which the hydrophobic silica and the hydrophobic titanium oxide are added is mixed with a ferrite carrier coated with a silicone resin and having a volume average particle diameter of 60 μm to prepare a developer having a toner concentration of 6% by mass. did. These developers were used as toner particles 1 to 11 and comparative toner particles 1
4 to 4, corresponding to developers 1 to 11 (the present invention), developer 1
2 to 15 (for comparison).

The characteristics of each of the obtained developers were evaluated as follows. << Evaluation of Image Density, Fog, Transfer Rate, and Halftone Uniformity >> Commercial Digital Copying Machine Konica Stios7075
Is used as an evaluator in a high temperature and normal humidity environment (33 ° C, 50%
RH), black solid image and image density, 0.
4 halftone image and white background image are printed continuously,
The maximum image density of the solid image and the density of fog "fog" on a white background were determined by a Macbeth reflection densitometer. The “transfer rate” is to form an image of 60 mg / cm ² on the photoreceptor,
The amount of adhesion per unit area transferred to paper as a transfer agent was measured. When it is 80% or more, the uniformity of the image density becomes firm and good. The homogeneity of the halftone was visually determined. "◎" indicates that 15 or more of 20 persons liked it, "○" indicates that 10 or more of 20 persons liked it,
"△", "Prefer" for what 5 or more of 20 prefer
Less than 3 out of 20 people were judged as "x". The number of sheets at the time of occurrence of image fouling "fogging" and the number of sheets at the time of occurrence of deposits on the photosensitive member were recorded.

<< Evaluation of Line Width: Evaluation of Reproducibility of Fine Line >> The line width of a line image corresponding to an image signal of a two-dot line is evaluated by a printing evaluation system "RT2000" (Yarman Corporation).
Manufactured). Both the line width of the first formed image and the line width of the 200,000th formed image are 200
If it is less than 10 μm and the change in line width is less than 10 μm, it can be said that fine line reproducibility is not a problem.

Table 3 shows the results of the above characteristic evaluation.

[0270]

[Table 3]

From Table 3, it can be seen that the sample of the present invention has a high image density, low fog, good transfer ratio, good halftone homogeneity, and excellent fine line reproducibility as compared with the comparative sample. It is clear that.

[0272]

According to the present invention, a toner for developing an electrostatic image, which has a high image density, low fog, a good transfer ratio and a good halftone homogeneity, and excellent fine line reproducibility. An image recording method and an image forming method to be used can be provided.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram showing a projected image of a toner particle having no corner, and FIGS. 1B and 1C are explanatory diagrams showing a projected image of a toner particle having a corner.

FIG. 2 is a sectional view illustrating an example of a fixing device used in the present invention.

[Explanation of symbols]

 Reference Signs List 8 recording material 10 heating roller 11 core metal 12 coating layer 13 heating member 20 pressure roll 21 core metal 22 coating layer T Toner image formed on recording material

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ryuji Kitani 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AA15 AB03 AB06 CA23 CB01 CB08 EA03 EA05 EA07

Claims (19)

[Claims] 1. A polymerizable monomer is polymerized in an aqueous medium to prepare a dispersion of resin particles. In the aqueous medium, in the presence of a surfactant represented by the following general formula (1), A toner for developing an electrostatic image, which is manufactured through a step of salting out, aggregating, and fusing the resin particles. General formula (1) R ₁ (OR ₂ ) _n OSO ₃ M [wherein, R ₁ represents an alkyl group or an arylalkyl group having 6 to 22 carbon atoms, and R ₂ represents an alkylene group having 2 to 6 carbon atoms. . n represents an integer of 1 to 11, and M represents a monovalent metal element or ammonium ion. ] 2. A dispersion of resin particles is prepared by polymerizing a polymerizable monomer in an aqueous medium, and in the aqueous medium, in the presence of a surfactant represented by the general formula (1), After undergoing the steps of salting out, aggregating, and fusing the resin particles, the resin particles are produced through a step of separating from the aqueous medium and drying, and the resin particles are represented by the general formula (1). The electrostatic image developing toner according to claim 1, wherein the toner contains 1 to 1000 ppm of the surfactant. 3. A dispersion of resin particles is prepared by polymerizing a polymerizable monomer in an aqueous medium, and in the aqueous medium in the presence of a surfactant represented by the following general formula (2): A toner for developing an electrostatic image, which is manufactured through a step of salting out, aggregating, and fusing the resin particles. Formula (2) R ₁ (OR ₂ ) _n SO ₃ M wherein R ₁ represents an alkyl group having 6 to 22 carbon atoms or an arylalkyl group, and R ₂ represents an alkylene group having 2 to 6 carbon atoms. , N represents an integer of 1 to 11. M represents a monovalent metal element or an ammonium ion. ] 4. A dispersion of resin particles is prepared by polymerizing a polymerizable monomer in an aqueous medium, and in the aqueous medium, in the presence of a surfactant represented by the general formula (2), After undergoing the steps of salting out, coagulating, and fusing the resin particles, the resin particles are produced through a step of separating from the aqueous medium and drying, and the resin particles are represented by the general formula (2). The toner for developing an electrostatic image according to claim 3, wherein the toner contains 1 to 1000 ppm of the surfactant. 5. A dispersion of resin particles is prepared by polymerizing a polymerizable monomer in an aqueous medium, and an interface represented by the general formula (1) or (2) is prepared in the aqueous medium. In the presence of an activator and a divalent or trivalent metal salt, the resin particles are produced through a step of salting out, agglomerating and fusing, and then a step of separating and drying the resin particles from the aqueous medium, In addition, the resin particles contain 1 to 1000 ppm of the surfactant represented by the general formula (1) or (2), and a total of 250 to 20 of a divalent or trivalent metal element used as an aggregating agent.
The toner for developing an electrostatic image according to any one of claims 1 to 4, wherein the toner comprises 000 ppm. 6. The electrostatic image according to claim 5, wherein the divalent or trivalent metal element used as the coagulant and the monovalent metal element added as the coagulation terminator are contained in a total amount of 350 to 35000 ppm. Development toner. 7. A dispersion liquid containing at least resin particles obtained by polymerizing a polymerizable monomer in an aqueous medium is prepared,
A step of salting out, coagulating, and fusing the resin particles in the aqueous medium in the presence of a metal salt to produce colored particles, and separating the obtained colored particles from the aqueous medium at a temperature equal to or higher than the Kraft point. A toner for developing an electrostatic image, which is manufactured through the following steps. 8. A dispersion containing at least resin particles obtained by polymerizing a polymerizable monomer in an aqueous medium,
In the aqueous medium, in the presence of the surfactant represented by the general formula (1) or the general formula (2) and a metal salt, the resin particles are salted out, aggregated, and fused to produce colored particles. A toner for developing an electrostatic image, wherein the toner is produced through a step of separating the obtained colored particles from the aqueous medium at a temperature higher than the Kraft point. 9. The electrostatic image development according to claim 1, wherein the number of toner particles having a shape factor in the range of 1.0 to 1.6 is 65% by number or more. For toner. 10. The electrostatic image development according to claim 1, wherein the number of toner particles having a shape factor in the range of 1.2 to 1.6 is 65% by number or more. For toner. 11. The toner for developing an electrostatic charge image according to claim 1, wherein toner particles having no corners account for 50% by number or more. 12. The electrostatic image developing toner according to claim 1, wherein the number average particle diameter of the toner is 3 to 8 μm. 13. When the particle size of toner particles is D (μm), the natural logarithm InD is plotted on the horizontal axis, and the horizontal axis is 0.23.
In the histogram indicating the number-based particle size distribution classified by intervals, the relative frequency (m1) of the toner particles included in the most frequent class, and the relative frequency (m1) of the toner particles included in the next most frequent class after the most frequent class The electrostatic image developing toner according to any one of claims 1 to 12, wherein a sum (M) of the relative frequency (m2) and the relative frequency (m2) is 70% or more. 14. A dispersion of resin particles is prepared by polymerizing a polymerizable monomer in an aqueous medium, and an interface represented by the general formula (1) or (2) is prepared in the aqueous medium. In the presence of an activator and a divalent metal salt or a trivalent metal salt, the method comprises a step of salting out, aggregating, and fusing the resin particles, and a step of separating and drying the resin particles from the aqueous medium. Of producing a toner for developing electrostatic images. 15. A dispersion liquid containing at least resin particles obtained by polymerizing a polymerizable monomer in an aqueous medium is prepared, and the resin particles are salted out in the aqueous medium in the presence of a metal salt. A method for producing a toner for developing an electrostatic image, characterized by producing colored particles by aggregation and fusion, and separating the obtained colored particles from the aqueous medium at a temperature not lower than the Kraft point. 16. A dispersion containing at least resin particles obtained by polymerizing a polymerizable monomer in an aqueous medium is prepared, and in the aqueous medium, a dispersion represented by the general formula (1) or (2) is obtained. The resin particles are salted out, agglomerated, and fused in the presence of the surfactant and the metal salt represented to produce colored particles, and the obtained colored particles are separated from the aqueous medium at a temperature equal to or higher than the Kraft point. A method for producing a toner for developing electrostatic images. 17. A dispersion of resin particles is prepared in an aqueous medium, and the resin is dispersed in the aqueous medium in the presence of the surfactant represented by the general formula (1) or (2). A step of salting out, aggregating, and fusing the particles together with a colorant dispersed in the aqueous medium to obtain toner particles, and a step of separating and drying the obtained toner particles from the aqueous medium. Item 17. A method for producing a toner for developing an electrostatic image according to Item 16. 18. In the step of separating and drying the toner particles from an aqueous medium, the toner particles are treated by the general formula (1).
The method for producing a toner for developing an electrostatic image according to claim 17, wherein the surfactant is separated from the aqueous medium at a temperature equal to or higher than the Kraft point of the surfactant represented by the general formula (2). 19. A step of forming an electrostatic image on an electrostatic image carrier, a step of developing the electrostatic image with a developer containing an electrostatic image developing toner to form a toner image, and the toner image 14. An image forming method including a step of transferring an image onto a transfer body, wherein the toner for developing an electrostatic image according to any one of claims 1 to 13 is used as the toner for developing an electrostatic image. Forming method.