JPH083664B2 - Method for producing polymerized toner - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a toner used in a method for developing a latent image.

BACKGROUND ART Toner that visualizes an electrical or magnetic latent image and the like is used in various processes for forming and recording images.

As an electrophotographic method which is one of such image forming processes, many methods are known as described in, for example, US Pat. No. 2,297,691. In this electrophotographic method, a photoconductive substance is generally used,
An electric latent image is formed on the photoconductor by various means, and then the latent image is developed with toner to form a toner image, and the toner image is transferred to a transfer material such as paper as necessary. After that, the toner image is fixed on the transfer material or the like by using heat, pressure, solvent vapor or the like to obtain a copy. In addition, various methods have been conventionally proposed as a method of developing with toner or a method of fixing a toner image,
A method suitable for each image forming process is adopted.

Conventionally, toners used for these purposes are generally prepared by melting and mixing a colorant composed of a magnetic material or dye / pigment in a thermoplastic resin, and uniformly dispersing the colorant, followed by fine pulverization and classification. Has been manufactured as a toner having a desired particle size.

According to this manufacturing method (pulverization method), a considerably excellent toner can be manufactured, but there is a certain limitation, that is, the selection range of the toner material. For example, the resin colorant dispersion must be sufficiently brittle and capable of being pulverized with economically available manufacturing equipment. From this request, the resin colorant dispersion has to be made sufficiently brittle, and when the dispersion is actually finely pulverized at a high speed, a particle group having a wide particle size range is likely to be formed. The problem arises that a large proportion of the over-milled particles are included in this group of particles. Further, such a highly brittle material is more susceptible to pulverization or pulverization when actually used for development in a copying machine or the like.

Further, in this pulverizing method, it is difficult to completely and uniformly disperse solid fine particles such as magnetic powder or a coloring agent in the resin, and depending on the degree of dispersion of the fixed fine particles,
Careful attention must be paid to the degree of this dispersion because it causes fog increase and image density decrease. In addition, the exposure of the colorant on the fracture surface of the colored resin fine powder may cause variations in toner development characteristics.

On the other hand, in order to overcome the problems of the toner by the pulverization method, a method for producing the toner by the suspension polymerization method has been proposed. In this suspension polymerization method, a monomer in which a polymerizable monomer and a colorant (further, if necessary, a polymerization initiator, a cross-linking agent, a charge control agent, and other additives) are uniformly dissolved or dispersed The composition is put into an aqueous phase (that is, a continuous phase) containing a suspension stabilizer, and granulated and polymerized with stirring to form toner particles.

This suspension polymerization method does not include a grinding step at all,
The toner material is not required to be brittle, and the toner is not exposed to the colorant on the fracture surface, which is a preferable toner manufacturing method. Furthermore, the shape of the obtained toner is spherical and excellent in fluidity and It has various advantages such as uniform chargeability. However, in this suspension polymerizability, it is possible to carry out the polymerization in a system in which the monomer composition particles are stably suspended without coalescence, or to obtain fine polymer particles having a uniform particle size distribution by the polymerization. Obtaining is not always technically easy.

Not only the toner obtained by this suspension polymerization method, but also the toner used in the method for developing a latent image is required to control various characteristics in order to faithfully reproduce the original image. Among the characteristics, controlling the particle size distribution is one of the most important problems. That is, when an image is formed using a toner that has a large particle size distribution and contains a large amount of particles having a non-regulated particle size, the sharpness of the image may be caused by toner scattering, fog on the image, or unevenness. Is deteriorated, and the developing characteristics of the toner vary, which causes problems such as deterioration of toner durability.

Conventionally, in this suspension polymerization method, various methods have been proposed to make the particle size distribution of the toner sharp. For example, a method of adjusting the particle size by combining a dispersant and an anionic surfactant in JP-A-57-42052, and a method of adjusting the particle size by adding an aqueous phase polymerization inhibitor in JP-A-56-156839. , Etc. have been proposed, but a polymerized toner having a preferable particle size distribution has not been obtained yet.

In particular, since a surfactant such as an anionic surfactant is difficult to remove even by washing with water, it has a strong tendency to remain on the surface of toner particles, and rather has a drawback that it tends to cause deterioration of toner developing characteristics.

From the above-mentioned problems, a dispersant having a sharp toner particle size distribution and having little influence on developing characteristics is desired.

OBJECT OF THE INVENTION It is an object of the present invention to provide a toner manufacturing method which solves the above-mentioned problems.

Another object of the present invention is to provide a method for producing a polymerized toner having a sharp particle size distribution with a good yield.

Still another object of the present invention is to provide a method for producing a polymerized toner having good developing characteristics.

SUMMARY OF THE INVENTION As a result of intensive studies, the present inventors have found that a combination of a polar substance contained in a monomer composition and a specific poorly water-soluble inorganic dispersant powder can adjust the interfacial tension appropriately. It has been found that it is feasible and further effectively suppresses the coalescence of toner particles to provide a polymerized toner having a sharp particle size distribution and excellent developing characteristics.

The method for producing a polymerized toner of the present invention is based on the above findings, and more specifically, it contains a poorly water-soluble inorganic dispersant powder soluble in Bronsted acid and has a pH of 2.5 to 6.0 or 7.
Polymerizing a monomer composition containing at least a polymerizable monomer, a polar substance, and a colorant in a dispersion medium substantially in the range of 1 to 11.0 and containing no water-soluble surfactant. The interfacial tension (A) between the composition obtained by removing the colorant from the monomer composition and the dispersion medium is (In the above formula, B represents the interfacial tension between the composition obtained by removing the colorant from the monomer composition and ion-exchanged water.)
It is characterized by satisfying the relationship of.

The function of the toner manufacturing method of the present invention having the above structure will be described below in comparison with the conventional method.

That is, generally, in the suspension polymerization method, in a dispersion medium typified by water, a substantially incompatible polymerizable monomer system is dispersed and polymerized to form toner particles. In order to obtain polymerized toner particles having a sharp distribution, droplets of a polymerizable monomer system (monomer composition particles) suspended in this liquid dispersion medium are made to have a constant diameter during the polymerization process.
How to maintain stability is a very important issue.

Conventionally, as a means for solving such a problem, generally, by adding a water-soluble surfactant to the dispersion medium, it is possible to reduce the interfacial tension of the monomer composition (oil droplets) -dispersion medium. It has been done. However, when such a water-soluble surfactant is added, it is unavoidable to generate emulsion particles (particle size of 1 μm or less) due to partial emulsification of the monomer composition, and moreover, such a surfactant is used as a toner. Since the toner tends to remain on the surface, the particle size distribution of the toner becomes broad and it is difficult to obtain a toner having good developing characteristics.

On the other hand, when the above water-soluble surfactant is not used,
Since the decrease in the interfacial tension is insufficient and the coarse monomer composition particles are more likely to be formed and the coarse toner particles are generated, the toner particle size distribution also tends to be broad.

On the other hand, in the production method of the present invention, the mutual action of the polar substance contained in the monomer composition and the inorganic dispersant soluble in Brönsted acid without using a water-soluble surfactant. Monomer composition particles (droplets) suitable for action-
It realizes the interfacial tension between the dispersion media. Therefore, according to the present invention, monomer composition particles having a fine particle size and a sharp particle size distribution substantially containing no emulsion particles can be obtained. Further, in the present invention, the poorly water-soluble inorganic dispersant powder more strongly protects the monomer droplets on the basis of the interaction with the polar substance described above, and the coalescence in the polymerization process of the droplets is also caused. For effective prevention, a polymerized toner having a sharp particle size distribution and excellent developing characteristics (by not using a conventional surfactant) can be obtained.

Further, according to the method of the present invention, it is possible to use a highly water-soluble polar substance having high hydrophobicity (which was difficult to be used in the conventional method) as the polar substance, and the particle size distribution is sharp and the developing property is high. It is possible to form a toner having further excellent (particularly, environmental characteristics).

Hereinafter, the present invention will be described in more detail. In the following description, “part” and “%” representing the quantitative ratio are based on weight unless otherwise specified.

DETAILED DESCRIPTION OF THE INVENTION In the production method of the present invention, a monomer composition containing at least a polymerizable monomer, a polar substance, and a colorant has an interfacial tension within a specific range with this monomer composition. Polymerized in a dispersion medium having.

The interfacial tension between the composition obtained by removing the colorant from the monomer composition (hereinafter referred to as “model composition”) and the dispersion medium is (A), and the interfacial tension between the model composition and ion-exchanged water is Assuming (B), in the present invention, Must be It is preferred that

the above When the value of exceeds 95, the formation of an emulsion of the monomer composition is recognized, which is not preferable. On the other hand, when this value is less than 5, the decrease in interfacial tension obtained by the polar substance is small, and the decrease in interfacial tension is impeded, so that the interfacial tension during granulation becomes relatively high and the granulation property deteriorates.

In the present invention, in measuring the above-mentioned interfacial tension (A) and (B), a coloring agent (pigment, magnetic particles, etc.) from the monomer composition is used.
The composition excluding (the model composition) is used.

According to the knowledge of the present inventors, even when such a model composition is used, the interfacial tension value which is substantially unchanged from the case where the monomer composition itself is used. Is preferable, and measurement error due to the presence of colorant particles (based on increase in viscosity) can be eliminated, which is preferable. Therefore, in the present invention, for convenience of performing the interfacial tension measurement,
Such a model composition is used.

This "model composition" needs to include at least a polymerizable monomer and a polar substance, but among various additives described below that are added to the monomer composition as necessary (interfacial tension). Charge control agent, which is an additive that does not adversely affect measurement,
And / or it preferably contains a crosslinking agent. Among the additives described below, a low softening point compound (paraffin or the like) may cause an error in the interfacial tension measurement (due to an increase in viscosity), so it is preferable not to include it in the model composition.

In the present invention, the preferred range of the interfacial tension (A) is
It is 18 to 2 dyne / cm, and the preferable range of the interfacial tension (B) is 22 to 3 dyne / cm.

In the present invention, as the interfacial tensions (A) and (B), a surface tension measuring device (manufactured by Kyowa Kagaku Co., Ltd.,
Using the KYOWA CBVP Surface Tension Meter A3), use the value measured by the usual method at room temperature (20-30 ° C).

 The outline of this interfacial tension measuring method is described below.

(1) Inject a dispersion medium (or ion-exchanged water) into a container that has been washed by a conventional method, and use a glass detection plate (for example, 24 mm
X 24 mm) is completely immersed.

(2) Next, the polymerizable monomer composition (model composition) is gently poured into the above container and allowed to stand at room temperature for 30 minutes.

(3) Next, the glass detection plate is gently pulled up and the interfacial tension is measured.

In the present invention, as the polar substance contained in the monomer, a substance having a polar group in the molecule and causing a decrease in interfacial tension at the interface between water and the polymerizable monomer system is used.

The polar substance used in the present invention is preferably a poorly water-soluble substance from the viewpoint of improving the environmental characteristics of the polymerized toner particles.

Here, the “poorly water-soluble substance” means a substance having a solubility of 1 g or less in 100 ml of water, preferably 500 mg or less, and particularly preferably 100 mg or less.

In the present invention, as such a polar substance, both low molecular weight compounds and high molecular weight compounds are used. In the case of high molecular weight compounds, the weight average molecular weight measured by GPC (gel permeation chromatography) is 5,000 to 50.
0,000 is well dissolved and dispersed in the polymerizable monomer,
Further, it is preferably used from the viewpoint of imparting durability to the toner.

More specifically, as the polar substance, anionic or cationic compounds shown below are preferably used.

(1) Anionic compound For example, a compound containing an anionic polar group such as a carboxyl group, a hydroxyl group, a dibasic acid group, a dibasic acid anhydride group, a sulfonic acid group, a sulfonate group, a phosphoric acid ester group, or an ether bond. More specifically, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, unsaturated dibasic acids, anhydrides of unsaturated dibasic acids, polar vinyls such as acrylic acid esters having a hydroxyl group, and methacrylic acid esters. Polymers or copolymers of monomers; or copolymers of these polar vinyl monomers with styrene, acrylic acid esters, and methacrylic acid esters; polyester resins; cyclized rubbers; chromium complexes of alkyl-substituted salicylic acid; isopropyltriisostearoyl Titanate, isopropyl tridecylbenzene sulfonyl titanate, isopropyl Lis (dioctyl pyrophosphate) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl trioctainor titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tric Titanate coupling agents such as milphenyl titanate, dicumylphenyloxyacetate titanate, diisostearoyl ethylene titanate, and the like;

(2) Cationic compound For example, a nitrogen-containing compound containing a basic polar group such as a primary amino group, a secondary amino group, and a tertiary amino group; specifically, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, etc. Polymer or copolymer of nitrogen-containing monomer, copolymer of styrene and the nitrogen-containing monomer,
Alternatively, a copolymer of styrene, unsaturated carboxylic acid ester (for example, acrylic acid ester, methacrylic acid ester) and the like and the nitrogen-containing monomer; Amino group-containing isopropyl tri (N-aminoethyl-aminoethyl) titanate and the like Examples include titanate coupling agents.

Here, when the polar substance is an anionic polar polymer, the acid value and / or the hydroxyl value is preferably 0.5 to 100, and the addition amount relative to 100 parts of the polymerizable monomer is 0.1 to 50. It is preferably part.

When the polar substance is a cationic polar polymer,
The amine value is preferably 0.5 to 100, and the addition amount thereof is preferably 0.1 to 50 parts with respect to 100 parts of the polymerizable monomer.

When the acid value and / or hydroxyl value or amine value of the polar polymer used in the present invention is less than 0.5, the effect of lowering the interfacial tension is small, while when it exceeds 100, the hydrophilicity is too strong, which is not preferable. .

Here, the acid value refers to the mg number of potassium hydroxide required to neutralize the carboxyl groups contained in 1 g of the sample.

The hydroxyl value is the number of mg of potassium hydroxide required to neutralize acetic acid bound to a hydroxyl group when 1 g of a sample is acetylated by a specified method.

Further, the amine value means the number of mg of potassium hydroxide required to neutralize the hydrochloric acid necessary to neutralize 1 g of the sample.

As described above, in the monomer composition, as an additive, a polar substance having a surface activity that dissolves and disperses in the polymerizable monomer, for example, a polar polymer, a polar copolymer, a cyclized rubber or a polyester, is added. When the polymerizable monomer is added and polymerized,
A preferable polymerized toner can be obtained. These polar polymers, polar copolymers or cyclized rubbers are polymerizable monomers 10
It is advisable to add 0.1 to 50 parts by weight, preferably 1 to 40 parts by weight, relative to 0 parts by weight. If it is less than 0.1 parts by weight, it is difficult to obtain a sufficient pseudocapsule structure, and if it exceeds 50 parts by weight, the amount of the polymerizable monomer becomes insufficient, and the properties of the polymerized toner tend to deteriorate. In the present invention, the polar polymer, a polar copolymer, a polymerizable monomer composition containing a cyclized rubber, etc., is suspended in the aqueous phase of an aqueous medium in which a fine powder dispersion stabilizer is dispersed. It is preferable to polymerize.

In this case, since the added polar polymer, polar copolymer or cyclized rubber, and polyester are gathered on the surface layer of the toner particles, they form a kind of shell, and the obtained particles have a pseudo capsule structure. To have. The relatively high molecular weight polar polymer, polar copolymer or cyclized rubber gathered in the particle surface layer imparts excellent properties such as blocking resistance, developability, charge controllability and abrasion resistance to the toner. To do.

On the other hand, the poorly water-soluble inorganic dispersant which is soluble in Bronsted acid used in the present invention is a poorly water-soluble inorganic compound, and soluble in Bronsted acid (more specifically, in 100 ml of water. On the other hand, it has a solubility of 20 g or more).

Here, the poorly water-soluble inorganic compound means a compound having a solubility of 10 mg or less (preferably 5 mg or less) in 100 ml of neutral ion-exchanged water.

Examples of the poorly water-soluble inorganic dispersant used in the present invention are shown below.

(1) Inorganic compound that is neutral or alkaline in water For example, calcium phosphate, magnesium phosphate, calcium sulfate, magnesium carbonate, calcium carbonate, Ca ₃ (PO ₄ ) ₂ · Ca (OH) _{2 and the} like.

(2) Inorganic compounds showing acidity in water For example, inorganic compounds composed of amphoteric elements (elements which produce amphoteric oxides) such as aluminum phosphate, zinc phosphate and zinc carbonate.

The particle size of such an inorganic compound is preferably 2 μm or less, more preferably 1 μm or less in terms of primary particles.

The particle diameter of the poorly water-soluble inorganic dispersant in the dispersion medium is measured by a Coulter counter.

That is, a sample (inorganic compound) was added to 1% saline to a concentration of about 10%, ultrasonically dispersed (36 KHz, 100 W, 1 minute) by a conventional method, and then a 100 μm orifice was used by a conventional method. Measure with a Coulter counter.

In the number distribution of the inorganic dispersant measured by such a method, the ratio of particles having a particle size of 5.04 μm or more is 5% in number.
The number of particles having a particle size of 3.17 μm or more is preferably 5% or less in terms of number.

Further, in the present invention, the volume average particle diameter of the inorganic dispersant in the dispersion medium is preferably 1 to 5 μm.
This volume average particle size means the particle size corresponding to the 50% value in the integral distribution as measured by a Coulter Counter.

The value of the volume average particle diameter of 1 to 5 μm in the present invention is
It is considered that this indicates that the inorganic dispersant fine powder is in an association state in which it is aggregated with a loose binding force. In the present invention, the fine powder is uniformly dispersed in the dispersion medium in an association state in which the fine powders are not separated from each other (non-aggregated state) but rather gathered with a loose restraining force, and further droplets ( It can be considered that the droplets are stabilized by being uniformly adsorbed on the surface of the (monomer composition particles). As a result, in the present invention, when the droplet containing the polymerizable monomer system changes in viscosity due to polymerization or the like and stability as the droplet decreases, an unstable phenomenon such as coalescence of droplets may occur. It is presumed that a polymerized toner that is hard to generate and has a sharp particle size distribution can be obtained.

For these inorganic dispersants, powdered inorganic compounds may be used as they are, but a method of producing a sparingly soluble inorganic compound in water using a substance such as sodium phosphate and calcium chloride, and using as it is in a fine particle state. In addition, it is preferable in that an inorganic compound having good dispersibility can be easily obtained.

In general, agglomeration of a powdery poorly soluble inorganic compound is generally a strong agglomeration state, and the particle size in this agglomeration state is also non-uniform. Therefore, when such a powder is used, carefully disperse it in water. Often necessary. However, if a method of forming a poorly soluble inorganic compound in water as described above is used, a good dispersed state of the inorganic compound can be easily obtained without such a concern.

Furthermore, when a poorly water-soluble compound is produced in water in this way, the water-soluble neutral salts obtained together with the poorly-soluble compound have the effect of preventing the dissolution of the monomer in water and the effect of increasing the specific gravity of water. Also has.

Hereinafter, examples of the reaction for forming the sparingly soluble inorganic compound will be shown, but the reaction is not limited thereto.

2Na ₃ PO ₄ + 3CaCl ₂ = Ca ₃ (PO ₄ ) ₂ + 6NaCl 2Na ₃ PO ₄ + 3MgSO ₄ = Mg ₃ (PO ₄ ) ₂ + 3Na ₂ SO ₄ 2Na ₃ PO ₄ + Al ₂ (SO ₄ ) ₃ = 2AlPO ₄ + 3Na ₂ SO ₄ Na ₂ PO ₄ + CaCl ₂ = CaSO ₄ + 2NaCl Na ₂ CO ₃ + MgSO ₄ = MgCO ₃ + Na ₂ SO ₄ Na ₂ CO ₃ + CaCl ₂ = CaCO ₃ + 2NaCl 2Na ₃ PO ₄ + 3ZnSO ₄ = Zn ₃ (PO ₄ ) ₂ + 3Na ₂ SO ₄ Na ₂ CO ₃ + ZnCl ₂ = ZnCO ₃ + 2NaCl Na ₂ CO ₃ + ZnSO ₄ = ZnCO ₃ + Na ₂ SO _{4 In the} present invention, the above poorly water-soluble PH of the dispersion medium containing a water-soluble inorganic dispersant, 2.5 ~ 6.0, or 7.1 ~ 11.0
And

When this pH is pH <2.5 or pH> 11.0, the acidity or alkalinity of the dispersion medium becomes too strong, resulting in insufficient granulation of the monomer composition.

On the other hand, when the pH of the dispersion medium is 6.1 <pH <7.1, the decrease in the interfacial tension between the monomer content and the composition surface is insufficient.

When adjusting the pH in this way, in a dispersion medium containing a poorly water-soluble inorganic dispersant, a water-soluble inorganic salt exhibiting alkalinity,
Alternatively, it is preferable to adjust the pH by adding a water-soluble inorganic salt exhibiting acidity and to adjust the dispersion medium so as to promote the surface activity of the polar substance.

Examples of the water-soluble inorganic salt showing alkalinity used in such a case include Na ₃ PO ₄ , Na ₂ CO ₃ , NaOH, KOH and the like.

Further, as the water-soluble inorganic salt showing acidity, MgSO ₄ , CaC
_{l 2, ZnSO 4, AlK (} SO 4) 2, Al 2 (SO 4) is _3, ZnCl ₂ or the like.

In such a method, a water-soluble inorganic salt may be added as needed.
You may use together 1 or more types.

The polar substance (surface active substance) and the poorly water-soluble inorganic dispersant have been described above. Examples of these preferable combinations are shown below, but the present invention is not limited to these exemplified combinations.

(A) Anionic compound (1) in combination with a poorly water-soluble inorganic dispersant (1) that exhibits neutrality or alkalinity in water, (B) cationic compound (2), and poorly water-soluble that exhibits acidity in water Combination with an inorganic dispersant (2).

In the above combination (A), it is more preferable to adjust the pH by adding a water-soluble inorganic salt showing alkalinity.

Further, in the combination of (B) above, it is more preferable to adjust the pH by adding a water-soluble inorganic salt showing acidity.

In the present invention, ZnCO ₃ among the inorganic compounds showing acidity in water can be used in combination with the anionic compound by adjusting the pH by adding a water-soluble inorganic salt showing alkalinity.

Further, in the above method, two or more kinds of poorly water-soluble inorganic dispersants may be used in combination, if necessary.

In the present invention, as the dispersion medium, one that is substantially incompatible with the polymerizable monomer is used, but it is preferable to use an aqueous dispersion medium.

In the present invention, as a dispersion medium containing a poorly water-soluble inorganic dispersant, one which does not substantially contain a known water-soluble surfactant is used. In the present invention, the water-soluble surfactant is 0.001 with respect to 100 parts of the inorganic dispersant powder described above.
It is possible to use it in an amount of not more than 1 part by weight, but there is no problem even if the water-soluble surfactant is not used at all.

In the present invention, when the monomer composition is granulated in the aqueous dispersion medium, it is granulated by, for example, a homomixer or a homogenizer having a turbine and a stator rotating at high speed. Generally, it is preferable to adjust the stirring speed and time so that the particles of the monomer composition have a size of 30 μm or less. The number of revolutions is preferably used so that the peripheral speed of the turbine is 10 to 30 m / sec, and the granulation time is not particularly limited, but is preferably 5 to 60 minutes.

The liquid temperature during the granulation step is such that the viscosity of the monomer composition is 1 to 1,000,000 c.
Adjusting to a temperature of ps, preferably 10-100,000 cps,
The particle size of the monomer composition particles can be 1 to 10 μm, and finally a developing toner having a weight average particle size of 1 to 10 μm can be produced. Since water or an aqueous medium containing water as a main component is usually used as the liquid dispersion medium, the liquid temperature of the dispersion liquid is preferably adjusted to 20 to 80 ° C (further 40 to 70 ° C).

In the dispersion liquid, with respect to 100 parts by weight of the monomer composition, the liquid dispersion medium is preferably present in 200 to 1000 parts by weight, the hardly water-soluble inorganic dispersant, the weight of the polymerizable monomer composition. It is preferably used in an amount of 1 to 20% by weight (further, 1 to 10% by weight).

Next, each component constituting the monomer composition will be described.

The polymerizable monomer used in the present invention is a monomer having a CH ₂ ═C group, and examples thereof include the following monomers.
That is, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4
-Dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonyl Styrene and its derivatives such as styrene, pn-decylstyrene, pn-dodecylstyrene; ethylene unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene; vinyl chloride, vinylidene chloride, vinyl bromide, fluorine Vinyl halides such as vinyl chloride; Vinyl esters such as vinyl acetate, vinyl propionate, and benzoe vinyl salt; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n methacrylate -Octyl, dodecyl methacrylate, methacryl Α-methylene aliphatic monocarboxylic acid esters such as 2-ethylhexyl acid, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate; methyl acrylates, ethyl acrylate, and n-butyl acrylate Acrylates such as isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; maleic acid, maleic acid Half ester; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone Ton acids; N- vinyl pyrrole, N- vinyl carbazole, N-
N-vinyl compounds such as vinylindole and N-vinylpyrrolidone; vinylnaphthalenes; acrylonitrile,
There are acrylic acid or methacrylic acid derivatives such as methacrylonitrile and acrylamide. These monomers can be used alone or as a mixture. Among the above-mentioned monomers, styrene or a styrene derivative alone,
Alternatively, it is preferably mixed with another monomer and used as a polymerizable monomer from the viewpoint of developing characteristics and durability of the toner.

In order to improve the fixability and anti-offset property in hot-press roller fixing, the monomer composition should have releasability such as waxes such as paraffin wax and low molecular weight polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene. A low softening point compound having a softening point of preferably 50
~ 130 ° C) is preferably added. In this case, the addition amount of the low softening point compound is preferably 1 to 300 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

Examples of the low softening point compound include paraffin, wax, low molecular weight polyolefin, modified wax having an aromatic group, hydrocarbon compound having an alicyclic group, natural wax, and a long-chain hydrocarbon chain having 12 or more carbon atoms (CH ₃ CH _{2 11} or
CH _{2 12} or more aliphatic carbon chains], long-chain carboxylic acids, esters thereof and the like can be exemplified. Different low softening point compounds may be mixed and used.

Specific examples of the low softening point compound include paraffin wax (manufactured by Nippon Oil Co., Ltd.), paraffin wax (manufactured by Nippon Oil Co., Ltd.), microwax (manufactured by Nippon Oil Co., Ltd.), microcrystalline wax (manufactured by Nippon Seiro Wax Co., Ltd.), and hard paraffin. Wax (made by Nippon Seiro), PE-130 (made by Hoechst), Mitsui High Wax 110P (made by Mitsui Petrochemical), Mitsui High Wax 220P (made by Mitsui Petrochemical), Mitsui High Wax 660P (made by Mitsui Petrochemical), Mitsui High Wax 210P (Mitsui Petrochemical), Mitsui High Wax 320P (Mitsui Petrochemical), Mitsui High Wax 410P (Mitsui Petrochemical), Mitsui High Wax 420P (Mitsui Petrochemical), Modified Wax JC-1141 (Mitsui) Petrochemical), modified wax JC-2130 (Mitsui Petrochemical), modified wax JC-4020 (Mitsui Petrochemical), modified wax JC-1142 (Mitsui Petrochemical), modified wax Box JC-
5020 (Mitsui Petrochemical); beeswax, carnauba wax,
Examples include montan wax.

In order to form a crosslinked polymer in the monomer composition, suspension polymerization may be carried out in the presence of the following crosslinking agent. In particular, when a polymer, copolymer or cyclized rubber is not added to the monomer composition, it is particularly preferable to add a crosslinking agent.

As the crosslinking agent, for example, divinylbenzene, divinylnaphthalene, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexane glycol dimethacrylate, neopentyl glycol Dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4-methacryloxydiethoxyphenyl) propane,
2,2'-bis (4-acryloxydiethoxyphenyl)
Propane, trimethylol propane trimethacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, dibromoneopentyl glycol dimethacrylate, diallyl phthalate and other general cross-linking agents as appropriate (combine two or more if necessary) Can be used.

If these cross-linking agents are used in a large amount, it becomes difficult for the toner to be melted by heat, and the heat fixing property or the heat pressure fixing property is inferior. If the amount used is too small, properties such as blocking resistance and durability required as toner deteriorate, and during heat roll fixing, part of the toner adheres to the roller surface without completely sticking to the paper, and It becomes difficult to prevent the offset phenomenon of being transferred to. Therefore, the amount of these crosslinking agents used is 0.001 to 15% by weight based on the polymerizable monomer.
It is preferable to use (more preferably 0.1 to 10% by weight).

The monomer composition contains a colorant, and dyes and pigments or magnetic particles are preferably used as this colorant.

As the dye / pigment, conventionally known dyes, carbon black, and pigments such as grafted carbon black in which the surface of carbon black is coated with a resin can be used (combination of two or more if necessary). . Such a dye / pigment is contained in an amount of 0.1 to 30% based on the polymerizable monomer.

A charge control agent and a fluidity modifier may be added (internally added) to the toner as necessary, but when they are internally added, a charge control agent or the like is usually added to the monomer composition. do it.
The charge control agent and the fluidity modifier may be used as a mixture (externally added) with the toner particles.

Examples of the charge control agent include metal complexes of organic compounds having a carboxyl group or a nitrogen-containing group, metal-containing dyes, nigrosine and the like. Examples of the fluidity modifier or the auxiliary agent for cleaning the surface of the latent image carrier (photoreceptor) include colloidal silica and metal salts of fatty acids. A filler such as calcium carbonate or finely divided silica may be incorporated in the toner in the range of 0.5 to 20% by weight for the purpose of increasing the amount. Further, a fluidity improver such as Teflon fine powder or zinc stearate powder may be added to the toner in order to prevent aggregation of the toner particles and improve the fluidity.

In order to produce a magnetic polymerized toner, magnetic particles may be added to the monomer composition. In this case, the magnetic particles also serve as a coloring agent (in whole or in part). As the magnetic particles that can be used in the present invention, substances that are magnetized by being placed in a magnetic field are used. For example, iron, cobalt, powder of ferromagnetic metal such as nickel or magnetite, hematite,
Examples include powders of alloys and compounds such as ferrite. Magnetic fine particles having a particle size of 0.05 to 5 μm, preferably 0.1 to 1 μm are used. When producing a toner having a small particle size (particle size of 8 μm or less), it is preferable to use magnetic particles having a particle size of 0.8 μm or less. The content of the magnetic particles is preferably 10 to 60 parts (more preferably 20 to 50 parts) per 100 parts of the monomer composition. Further, these magnetic fine particles may be treated with a treating agent such as a silane coupling agent or a titanium coupling agent, or an appropriate reactive resin or the like. In this case, depending on the surface area of the magnetic fine particles and the density of hydroxyl groups existing on the surface, a treatment amount of 5 parts or less (preferably 0.1 to 3 parts) with respect to 100 parts of the magnetic particles gives a sufficient polymerizable monomer. As a result, the dispersant is obtained and does not adversely affect the physical properties of the toner. Further, lipophilic magnetic particles and hydrophilic magnetic particles may be mixed and used.

According to the knowledge of the present inventors, when a water-soluble polymerization initiator is used, the generated polymerized toner has reduced moisture resistance,
Since development characteristics and blocking resistance are deteriorated at high temperature and high humidity, it is preferable to use a substantially water-insoluble polymerization initiator in order to produce a polymerized toner having excellent environmental characteristics.

As described above, the polymerization initiator used in the present invention is preferably substantially water-insoluble. In the present invention, the substantially water-insoluble polymerization initiator is one having a solubility of 1 g or less in 100 g of water at room temperature, and preferably water 10
0.5 g or less relative to 0 g, particularly preferably 0.
It has a low solubility of 2 g or less. For 100g of water
When it has a solubility of more than 1 g, the decomposition product of the polymerization initiator remaining on the surface of the polymerized toner particles after completion of the polymerization is
It is not preferable because it lowers the moisture resistance of the polymerized toner. In addition, the polymerization initiator used in the present invention is soluble in the polymerizable monomer, and is generally good in the amount range used (1 to 10 parts by weight of the polymerization initiator with respect to 100 parts by weight of the monomer). It is preferable to have a solubility property of dissolving in a polymerizable monomer.

Examples of such a polymerization initiator include 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile and 1,1′-azobis (cyclohexane-1-carbonitrile). ), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, and other azo- or diazo-type polymerization initiators such as azobisisobutyronitrile (AIBN); benzoyl peroxide, methyl ethyl ketone peroxide , Isopropyl peroxycarbonate, Kyumen hydroperoxide, 2,4-
Peroxide-based polymerization initiators such as dichlorylbenzoyl peroxide and lauroyl peroxide are exemplified.

It is also preferable to use a mixture of two or more polymerization initiators for the purpose of adjusting the molecular weight and molecular weight distribution of the polymer or for adjusting the reaction time.

The amount of the polymerization initiator used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerized monomer. When the amount of the polymerization initiator used is less than 0.1 parts by weight, it is difficult to uniformly disperse or impart a sufficient amount of the polymerization initiator to each monomer composition particle, and when the amount is 20 parts by weight or more, the polymerization amount is too large. The molecular weight of the product becomes too low and the tendency for the polymerization reaction to occur nonuniformly increases.

Such a polymerization initiator can be added to the dispersion containing the monomer composition particles after the monomer composition is granulated, but the polymerization is uniformly performed on each monomer composition particle. From the viewpoint of dispersing or providing the initiator, it is preferable that the initiator is contained in the monomer composition before granulation.

The suspension polymerization reaction is usually performed at a polymerization temperature of 50 ° C. or higher, and the upper limit temperature is set in consideration of the decomposition rate of the polymerization initiator. If the set polymerization temperature is too high, the polymerization initiator will be rapidly decomposed, which is not preferable.

In the present invention, after confirming that the formed monomer composition particles have a predetermined particle size, the liquid temperature of an aqueous medium or the like containing the particles (for example, 55 to 70 ° C.) is adjusted to carry out polymerization. A method of proceeding the reaction, a method of adjusting the liquid temperature of the dispersion medium, and proceeding the polymerization at the same time as the granulation and dispersion are used.

After completion of the polymerization reaction of the monomer composition, post-treatment is carried out by a usual method to obtain polymerized toner particles. For example,
Bronsted acid is added to the system containing the produced polymer particles to remove the poorly water-soluble inorganic dispersant, and then the polymer particles are recovered by an appropriate method such as filtration, decantation, or centrifugation, and dried. As a result, a polymerized toner is obtained.

The Bronsted acid-soluble sparingly water-soluble inorganic dispersant used in the present invention can be easily removed from the toner particle surface by the above-mentioned acid (or alkali) treatment. In the toner in which the dispersant is removed in this way (based on the residual dispersant)
There is substantially no adverse effect of making the surface of the toner hydrophilic, and good toner developing characteristics can be obtained.

The polymerized toner obtained by the production method of the present invention can be applied to a known dry electrostatic image development method. For example, a two-component developing method such as a cascade method, a magnetic brush method, a microtoning method, or a two-component AC bias developing method; a magnetic toner such as a conductive-component developing method, an insulating-component developing method or a jumping developing method is used. -Component developing method; powder cloud method and fur brush method; non-magnetic developing method in which toner is carried to a developing section by being held on a toner carrier by electrostatic force and is used for development; electric field curtain method Can be applied to the electric field curtain developing method in which the toner is conveyed to the developing section and used for the development. The toner obtained by the method of the present invention can be particularly preferably applied to a developing method using a small particle size toner having a weight average particle size of about 2 to 8 μm, which requires a sharp particle size distribution.

Effects of the Invention As described above, according to the method for producing a polymerized toner of the present invention, a slightly water-soluble inorganic fine powder in a dispersion medium and a polar substance in a monomer composition are used, and the composition / dispersion medium is used. By realizing a preferable interfacial tension between them, the monomer composition particles can be formed in a suitable state, and a polymerized toner having a sharp particle size distribution and good developing characteristics can be obtained in good yield.

Hereinafter, the present invention will be described more specifically based on Examples.

Examples Example 1 25.5 g of Na ₃ PO ₄ .12H ₂ O was added to 1000 ml of ion-exchanged water, and a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) was used for 10000r.
Stirred at pm. An aqueous solution prepared by dissolving CaCl ₂ .2H ₂ O in 14.2 g of ion-exchanged water (200 ml) was gradually added to the Na ₃ PO ₄ solution under stirring with the homomixer, and dispersion containing calcium phosphate, which was a poorly water-soluble inorganic fine powder, was added. A medium (pH = 10.5) was obtained. When measured with a Coulter counter, in the number distribution of the fine powder, the ratio of particles having a particle size of 4.0 μm or more was 1% or less in number.

The above polymer-monomer mixture was mixed with an attritor 60
Mixing at ℃, the monomer composition (viscosity at 60 ℃ 300 cp
s) was prepared.

In a stainless container having a capacity of 2 liters containing a dispersion medium containing calcium phosphate prepared as described above, the monomer composition obtained above was charged, and under a N ₂ atmosphere, TK homomixer (special (Manufactured by Kika Kogyo) was stirred at 10,000 rpm for 30 minutes to granulate the monomer composition. Then, the monomer composition was polymerized at 60 ° C. for 10 hours while stirring with a paddle stirring blade.

After the completion of the above reaction, the reaction product was cooled, dehydrated, washed with hydrochloric acid (1 / 10N), further washed with water, dehydrated and dried to obtain a polymerized toner. When the particle size of the obtained toner was measured with a Coulter counter (aperture diameter: 100 μm), the volume average particle size was 8.5 μm, and the particle size distribution was extremely narrow.

15 g of the toner obtained above, 85 g of an insulating carrier having an average particle diameter of 50 μm (consisting of iron trioxide and an epoxy resin), hydrophobic silica (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.) 0.75 g, and zinc stearate 0.45 g of powder was mixed to prepare a developer, and the electrophotographic characteristics were evaluated under the following conditions.

As the developing device, one having a schematic sectional view in the drawing was used. The image carrier 1 has a selenium photoreceptor 11, the peripheral speed of the image carrier 1 is 100 mm / sec, the maximum potential of the electrostatic charge image formed on the image carrier 1 is +750 V, and the sleeve (developer carrier). 2 outer diameter
20mm, its peripheral speed is 100mm / sec, magnet roller 3
The magnetic flux density in the vertical direction on the sleeve surface of N and S poles is 1000
Gauss, thickness of developer layer 200μm, gap between sleeve 2 and image carrier 1 300μm, bias voltage applied to sleeve is DC voltage component + 200V, AC voltage component is 3.0KHz and 1400Vp
When development was carried out at p, the electrostatic latent image on the image carrier 1 was well developed.

The toner image formed by this development is electrostatically transferred to plain paper, and the toner image on the plain paper is fixed to a hot-pressure roller fixing device (7 Kg / After fixing under a pressure of cm ² through a nip width of 9 mm and a paper traveling speed of 300 mm / sec., 15
At a fixing temperature of 0 ° C. (fixing roller surface temperature), this toner image was fixed well. The obtained fixed image showed no image fog and had an image density (Dmax) of 1.44.

In the developing device shown in the drawing, the toner T having an external additive (silica powder or the like) is quantitatively supplied to the lower chamber by the supply roller 4 and the elastic member 5 and mixed with the carrier to be mixed with the developer 6. To form. A DC bias power source 8 applies a DC bias, and an AC bias power source 9 applies an AC bias to the sleeve 2 including the magnet roller 3 and the doctor blade 7. With the rotation of the sleeve 2 in the A direction, the developer 6 is conveyed, and the aluminum cylinder 12 and the selenium photoreceptor 11 are transferred.
And is used for developing an electrostatic latent image on the image carrier 1. The developer layer regulating member 10 also plays the role of the outer wall of the developing device.

90 g of styrene, 10 g of 2-ethylhexyl methacrylate, 10 g of cyclized rubber, Bontron E-81, 2 g, NK
The interfacial tension (interfacial tension (A)) of the model composition consisting of ester 2G and 1 g with respect to the dispersion medium containing calcium phosphate prepared above was measured by the surface tension measuring device (KYOWA.CBVP Surface Tension) by the method described above. It was measured at room temperature (25 ° C) using Meter A3). This interfacial tension (A)
Was 2.0 dyne / cm.

On the other hand, the interfacial tension (B) of the model composition with respect to ion-exchanged water was similarly measured and found to be 3.2 dyne / cm.

Example 2 The above polymerizable monomer mixture was mixed with an attritor to 60
Mixing at ℃, the monomer composition (viscosity at 60 ℃ 600cp
s) was prepared.

In a stainless container having a capacity of 2l, a dispersion medium containing a phosphoric acid Improvement of a Saline prepared in the same manner as in Example 1 was charged with a monomer composition obtained above, N ₂ atmosphere TK homomixer under 60 ° C. ( (Made by Tokushu Kika Kogyo) was stirred at 10,000 rpm for 30 minutes for granulation. After that, using paddle blade stirring for 20 hours,
The monomer composition was polymerized at 60 ° C.

The above reaction product was cooled, dehydrated, washed with hydrochloric acid (1 / 10N), washed with water, further dehydrated and dried to obtain a polymerized toner. When the particle size of the obtained toner was measured with a Coulter counter (aperture diameter 100 μm), the volume average diameter was 9.5 μm, and the ratio in the volume distribution of the coarse powder of 16 μm or more was 3% by volume, showing an extremely narrow particle size distribution. there were.

A developer was prepared by mixing 100 g of the toner obtained above with 0.6 g of hydrophobic silica (Talanox-500, manufactured by Tarco).

When this developer was applied to Canon Copier NP-7550 and image formation (image formation test) was performed at room temperature and normal humidity (25 ° C, 60%), good image quality and density were obtained. Was given.

When images were printed in the same manner as above at a high temperature and high humidity of 32.5 ° C. and 90%, images with good image quality and density were obtained.

Example 3 Na ₃ PO ₄ hydrous salt (Na ₃ PO ₄ .12H) was added to 1000 ml of ion-exchanged water.
₂ O) 30.8 g was added, and the mixture was stirred at 10,000 rpm using a TK homomixer (made by Tokushu Kika Kogyo).

An aqueous solution prepared by dissolving 29 g of Al ₂ (SO ₄ ) ₃ hydrate salt (Al ₂ (SO ₄ ) ₃ · 50% content) in 200 ml of deionized water was gradually added to the Na ₃ PO ₄ solution while stirring with the homomixer. In addition to, a hydroxide medium containing aluminum phosphate, which is a poorly water-soluble inorganic fine powder (pH =
3.8) was obtained.

When the particle size of the fine powder in the dispersion medium was measured by a Coulter counter, the ratio of particles having a particle size of 4.0 μm or more was 1% in number.

Using an attritor, the above polymerizable monomer mixture
Monomer composition by mixing at 60 ℃ (viscosity at 60 ℃ 300 cp
s) was prepared.

The above monomer composition was placed in a stainless steel container having a capacity of 2 l and containing the dispersion medium containing aluminum phosphate prepared above, and the same treatment as in Example 1 was performed to obtain a volume average diameter of 8 μm.
Toner was obtained.

A developer was prepared by mixing 100 g of the toner obtained above with 0.6 g of hydrophobic silica treated with amino-modified silicone oil. When this developer was applied to Canon Copier NP-3525 to print out, the image quality
An image with good density was obtained. Also, 32.5 ℃, 90%
Similarly, good images were obtained even under high temperature and high humidity.

Example 4 8.91 ml of Na ₂ CO ₃ anhydrous salt (Na ₂ CO ₃ ) was added to 1000 ml of ion-exchanged water.
1 g using TK homomixer (made by Tokushu Kika Kogyo)
It was stirred at 0000 rpm. A solution of anhydrous ZnCl ₂ (ZnCl ₂ ) dissolved in 200 ml of 11.3 g ion-exchanged water was added to the above Na ₂ CO ₃ solution,
The homomixer was gradually added with stirring to obtain a dispersion medium containing ZnCO ₃ (pH = about 7.5). When measured with a Coulter counter, the volume average diameter of ZnCO ₃ was 2.9 μm, and the ratio of particles having a particle diameter of 4.0 μm or more was 1% or less in number.

A toner was obtained in the same manner as in Example 2 except that the dispersion medium containing ZnCO ₃ obtained above was used.

When the particle size of the obtained toner was measured with a Coulter counter, the volume average diameter was 8.5 μm. When an image was formed using this toner in the same manner as in Example 2,
An image with good image quality and density was obtained.

Example 5 8.46 g of Na ₂ CO ₃ anhydrous salt was added to 1000 ml of ion-exchanged water, and T
The mixture was stirred at 10,000 rpm using a K homomixer (made by Tokushu Kika Kogyo). A solution obtained by dissolving 12.3 g of ZnCl ₂ anhydrous salt in 200 ml of ion-exchanged water was gradually added to the Na ₂ CO ₃ solution under stirring with the homomixer to obtain a dispersion medium (pH = about 5.8) containing ZnCO ₃ . . When measured with a Coulter counter, the volume average diameter of ZnCO _{3 in} the dispersion medium is 2.9 μm, and the particle diameter is 4.
The ratio of particles of 0 μm or more was 1% or less in number.

A toner was obtained in the same manner as in Example 3 except that the dispersion medium containing ZnCO ₃ obtained above was used.

When the particle size of the obtained toner was measured with a Coulter counter, the volume average diameter was 9.5 μm. When this toner was used to perform image formation in the same manner as in Example 3, an image having good image quality and density was obtained.

Example 6 To 500 ml of ion-exchanged water, 4.23 g of anhydrous Na ₂ CO ₃ salt was added, and TK was added.
The mixture was stirred at 10,000 rpm using a homomixer (made by Tokushu Kika Kogyo). A solution prepared by dissolving 6.15 g of ZnCl ₂ anhydrous salt in 200 ml of ion-exchanged water was gradually added to the Na ₂ CO ₃ solution under stirring with a homomixer to obtain a dispersion medium containing ZnCO ₃ .

On the other hand, in another container, in the same manner as above, using 5.25 g of Na ₂ CO ₃ anhydrous salt and 9.8 g of CaCl ₂ hydrate (CaCl ₂ · 2H ₂ O), a dispersion medium containing CaCO ₃ was prepared. Obtained.

The two dispersion media, the ZnCO ₃ -containing dispersion medium and the CaCO ₃ -containing dispersion medium obtained above, are mixed, and the dispersion medium (pH
= About 5.8).

The volume average diameter of the inorganic fine powder in this dispersion medium was 2.9 μm.

A toner was obtained in the same manner as in Example 3 except that the dispersion medium thus obtained was used. The volume average diameter of the obtained toner was 9.0 μm.

Example 7 9.98 g of Na ₂ CO ₃ anhydrous salt was added to 800 ml of ion-exchanged water, and TK was added.
The mixture was stirred at 10000 rpm using a homomixer. A solution of 5.65 g of ZnCl ₂ anhydrous salt dissolved in 200 ml of ion-exchanged water was added to the above Na
₂ Add to the CO ₃ solution gradually with stirring with a homomixer and add ZnCO ₃
A dispersion medium containing was obtained. Next, a solution prepared by dissolving 9.8 g of CaCl ₂ hydrous salt in 200 ml of ion-exchanged water was gradually added to the above dispersion medium while stirring with a homomixer, and a dispersion medium containing CaCO ₃ and ZnCO ₃ (pH = about 7.5). Got

The volume average diameter of the inorganic fine powder in this dispersion medium was 2.7 μm.

A toner was obtained in the same manner as in Example 2 except that the dispersion medium obtained above was used. The volume average diameter of the obtained toner is 10.5 μm.
Met.

Example 8 30.8 g of Na ₃ PO ₄ hydrous salt was added to 1000 ml of ion-exchanged water, and T
10,000 rpm using K homomixer (made by Tokushu Kika Kogyo)
It was stirred at. 28 g of Al ₂ (SO ₄ ) ₃ hydrous salt is deionized water 200 ml
Was gradually added to the above Na ₃ PO ₄ solution under stirring with a homomixer, and the dispersion medium containing aluminum phosphate (pH
= 4.5) was obtained.

When the particle size of aluminum phosphate in this dispersion medium was measured by a Coulter counter, the ratio of particles having a particle size of 4.0 μm or more was 1% in number.

A polymerized toner was obtained in the same manner as in Example 3 except that the dispersion medium obtained above was used.

When images were formed using this polymerized toner in the same manner as in Example 3, good images were obtained in the same manner as in Example 3.

Example 9 Into 1000 ml of ion-exchanged water, 24.5 g of Na ₃ PO ₄ .12H ₂ O was added,
Using TK homomixer (made by Tokushu Kika Kogyo), 10,000 rpm
It was stirred at. A solution of 14.2 g of CaCl ₂ · 2H ₂ O dissolved in 200 ml of ion-exchanged water was gradually added to the Na ₃ PO ₄ solution under stirring with a homomixer, and a dispersion medium containing calcium phosphate (pH) was added.
= 10.5) was obtained. When the particle size of the calcium phosphate was measured with a Coulter counter, the ratio of particles having a particle size of 4.0 μm or more was 1% or less in number.

Instead of 10 g of the cyclized rubber of Example 1, 10 g of a polyester (acid value 10, hydroxyl value 15) which is a condensation polymer of etherified diphenol and terephthalic acid and trimellitic anhydride
Except that the same composition as in Example 1 was used, and
A toner having a volume average diameter of 8.5 μm was obtained in the same manner as in Example 1 except that the calcium phosphate-containing dispersion medium obtained above was used.

When an image was formed using this toner in the same manner as in Example 1, a good image was obtained as in Example 1.

Comparative Example 1 30.8 g of Na ₃ PO ₄ hydrous salt was added to 1000 ml of ion-exchanged water, and a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) was used for 10,0
It was stirred at 00 rpm. 28 g of Al ₂ (SO ₄ ) ₃ hydrous salt was added to ion-exchanged water 2
The solution dissolved in 00 ml was gradually added to the Na ₃ PO ₄ solution under stirring with a homomixer to obtain a dispersion medium (pH = 4.5) containing aluminum phosphate.

When the particle size of aluminum phosphate in this dispersion medium was measured by a Coulter counter, the ratio of particles having a particle size of 4.0 μm or more was 1% in number.

The monomer composition was polymerized in the same manner as in Example 1 except that the dispersion medium obtained above was used, but a stable granular polymer could not be obtained.

Comparative Example 2 Na ₃ PO ₄ .12H ₂ O 24.5 g was added to 1000 ml of ion-exchanged water,
10,000rp using TK homomixer (made by Tokushu Kika Kogyo)
Stir at m. A solution prepared by dissolving 14.2 g of CaCl ₂ · 2H ₂ O in 200 ml of ion-exchanged water was gradually added to the Na ₃ PO ₄ solution under stirring with a homomixer, and then 0.15 g of 20% water-soluble sodium dodecylbenzenesulfonate was added. Thus, a dispersion medium containing calcium phosphate was obtained. When the particle size of calcium phosphate was measured with a Coulter counter, the particle size was 4.0 μmm
The ratio of the above particles was 1% or less in number.

A toner was obtained in the same manner as in Example 2 except that the dispersion medium obtained above was used.

After classifying the obtained toner to a volume average diameter of 9.5 μm,
An image was formed in the same manner as in Example 2 using the toner after the classification, and only a rough image was obtained under a high temperature and high humidity of 32.5 ° C. and 90%.

The interfacial tension (A) between the composition (model composition) obtained by removing the colorant from the monomer composition used in each of the examples and comparative examples described above, and the model composition and ion-exchanged water. The interfacial tension (B) was measured in the same manner as in Example 1.

Determined from the values of these interfacial tensions (A) and (B) The values of are shown in the table below.

In addition, the following results are the measurement results obtained using a model composition containing no polymerization initiator and lance fin wax 155 ° F, which may adversely affect the measurement results, at the interfacial tension measurement temperature (normal temperature). is there.

[Brief description of drawings]

The drawing is a schematic cross-sectional view showing the developing device used in the examples. 1 ... Image carrier 2 ... Sleeve 3 ... Magnet roller 4 ... Supply roller 5 ... Elastic member 6 ... Developer 7 ... Doctor blade 8, 9 ... Bias power supply 10 ... Developer layer regulating member

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiroaki Kawakami 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kuniko Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Hitoshi Kanda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-56-110945 (JP, A) JP-A-51-14895 (JP) , A) JP 59-123852 (JP, A) JP 59-152449 (JP, A) JP 61-22354 (JP, A)

Claims (1)

[Claims] 1. A dispersion containing a poorly water-soluble inorganic dispersant powder soluble in Bronsted acid, having a pH in the range of 2.5 to 6.0 or 7.1 to 11.0, and containing substantially no water-soluble surfactant. A method of polymerizing a monomer composition containing at least a polymerizable monomer, a polar substance, and a colorant in a medium; a composition obtained by removing the colorant from the monomer composition; The interfacial tension (A) with the dispersion medium is (In the above formula, B represents the interfacial tension between the composition obtained by removing the colorant from the monomer composition and ion-exchanged water.)
The method for producing a polymerized toner is characterized by satisfying the following relationship.