JPH05271312A - Composite particle of polymer and solid component and its production - Google Patents

Abstract

PURPOSE:To provide monodispersed composite polymer particles having large diameter and compounded and/or included with a solid component and to provide monodispersed and large diameter particles suitable as a toner for electrophotography and carrier for medical diagnostic. CONSTITUTION:A dispersion of polymer particles essentially free from dispersing agent is incorporated with an ethylenic unsaturated monomer unit same as and/or different from the ethylenic unsaturated monomer unit constituting the polymer particle and the mixture is subjected to seed polymerization in the presence of a water-soluble radical polymerization initiator to obtain monodispersed and large diameter polymer particles. In the above process, an aqueous dispersion of a solid component is added when the polymerization conversion of the seed polymerization reaches 20-85%, the stirring speed is increased from a stationary state to a definite secondary stirring speed, the mixture is stirred at the above speed and the monomer is polymerized at the stationary stirring speed. The obtained polymer particles compounded with the solid component is incorporated with less than critical amount of an ethylenic unsaturated monomer and the composition is subjected to seed emulsion polymerization.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monodisperse polymer particle having a large particle size, and more particularly to a spherical or amorphous polymer particle having a monodisperse particle size distribution and a particle size of micron.

[0002]

2. Description of the Related Art Emulsion polymerization method, suspension polymerization method, dispersion polymerization method and the like are known as conventional spherical particle polymerization methods. Each of these polymerization methods has advantages and disadvantages, and is characterized by the obtained particle size, particle size distribution, molecular weight, and particle surface state. By the emulsion polymerization method, high molecular weight monodisperse particles can be easily obtained, but only fine particles having a particle diameter of 1.0 μm or less can be obtained. On the other hand, the suspension polymerization method gives large particles of 10 μm or more, but its particle size distribution is polydisperse. Further, the dispersion polymerization method is known to obtain particles having a particle size on the order of micron, but the monomers constituting the polymer particles are limited, and it is not easy to control the molecular weight and the particle size. Since an organic solvent is used as the solvent, there is a concern about environmental problems, and selection of these is limited similarly to the monomer.

Further, the polymer dispersant often used in the suspension polymerization method and the dispersion polymerization method is often fixed to the particle surface and difficult to be easily removed from the particle interface, and the originally desired property of the polymer particle surface. The phenomenon of exhibiting different properties from is often observed.

Further, the compounding / encapsulation of these polymer particles with other components, such as pigments, is particularly effective in emulsion polymerization.
It is known that the dispersion polymerization method is very difficult.
On the other hand, in suspension polymerization, it is possible to incorporate other solid components in the particles, but for this reason it is necessary to disperse the solid components in the monomer before polymerization, and this requires a great deal of energy. It has the drawback of

In order to improve these drawbacks, for example, according to Journal of Polymer Science; Polymer Symposium, 72 , 225-240 (1985), polymer particles prepared by an emulsion polymerization method are used as an oligomer or A "two-step swelling method" has been proposed in which the solvent is swollen, and then the monomer is swollen to perform polymerization.

[0006]

However, the above-mentioned method of the prior art not only requires a complicated technique of two-step swelling but also requires a long time for the swelling process itself, which significantly increases the productivity. It has the drawback of chipping. Regarding the problem when compounding / encapsulating solid components,
It is obvious that the above method does not solve anything.

Since monodisperse particles having a particle size of several μm or more do not require classification operation, they are used as electrophotographic toners, gap control agents for liquid crystal display plates, medical diagnostic carriers, standard particles for particle size measurement, and chromatography. It is used as a filler for cosmetics, a filler for cosmetics, and a texture modifier for synthetic leather.

Accordingly, an object of the present invention is to provide composite polymer particles in which specific solid components are further composited and / or encapsulated with monodispersed and large-sized polymer particles.

Another object of the present invention is to provide a monodisperse and large particle which is compatible with the above-mentioned applications, particularly electrophotographic toner and medical diagnostic carrier.

[0010]

[Means for Solving the Problems] In order to achieve the above object, the present inventors have conducted extensive studies and completed the present invention. That is, to a polymer particle dispersion liquid that does not substantially contain a dispersant, an ethylenically unsaturated monomer that is the same as and / or different from the ethylenically unsaturated monomer unit that constitutes the polymer particles is added to be water-soluble. After adding an aqueous dispersion of solid components in a state where the polymerization conversion rate of seed polymerization is 20 to 85% with respect to monodispersed and large-sized polymer particles obtained by seed polymerization in the presence of a radical polymerization initiator. It is achieved by accelerating from a constant stirring speed to a constant secondary stirring speed, stirring at this speed for a certain period of time, and then returning to the constant stirring speed again to proceed with polymerization.

Further, it is achieved by adding a critical amount or less of the ethylenically unsaturated monomer to the polymer particles in which the solid component produced as described above is complexed, and performing seed emulsion polymerization.

Next, the present invention will be described in detail.

(Seed Particles) In the present invention, in the polymerization process of seed emulsion polymerization, an aqueous dispersion containing a solid component to be complexed is added, and at the same time, the stirring speed is increased from a steady speed to a high secondary stirring speed. , Complexing the solid component with the polymer particles. As the polymer particles used here, particles selected from emulsion polymerization, suspension polymerization and dispersion polymerization can be used. Particularly, polymer particles produced by emulsion polymerization are useful because they have a wide selection range of monomers, can easily introduce various functional groups, and can easily produce particles having a narrow particle size distribution. It is necessary to remove the dispersant from the polymer particles produced by each method by washing operation or the like. In the case of emulsion polymerization, it is necessary to remove the surfactant by using dialysis, ultrafiltration or the like. At this time, the concentration of the surfactant may be set to the critical micelle formation concentration (abbreviated as CMC) or less.

Further, the soap-free emulsion polymerization is very useful because it does not use a surfactant and produces particles having a clean particle surface. Since the soap-free emulsion polymerization does not use a surfactant as a dispersant, it has a feature that not only a complicated removal operation of the surfactant is required but also the particle size distribution is narrow.

As a completely different method, a polymer dissolved in a good solvent is added to a poor solvent, or conversely, a poor solvent is added,
At this time, it is possible to form particles by stirring at a suitable stirring speed or by further combining with a suitable dispersant, and the particles thus produced may be used in the same manner as the other particles described above. It is possible.

(Dispersant) The polymer particle dispersion liquid which does not substantially contain a dispersant in the present invention means a dispersion liquid which contains seed particles, and a state in which a dispersant is not substantially contained means:
Except for the polymerization reaction in which the particle size growth of seed particles occurs during seed polymerization, the concentration is below the concentration at which new particles are not generated in the aqueous phase.

Specifically, when the dispersant is a surfactant,
The surfactant present in the water phase is the critical micelle formation concentration (CM
C) It shows that it is the following. At this time, the amount of the surfactant adsorbed on the polymer particles does not matter, but it is not preferable that the surfactant desorbed from the particle surface during the polymerization process exceeds CMC. This is because the desorbed surfactant is CMC.
When micelles are formed as described above, unreacted monomers in the polymerization process promote emulsion polymerization in micelles in parallel to promote the production of new particles, and as a result, polydisperse polymer particles are produced. This is because

The concentration of the dispersant is preferably CMC or less, and more preferably in the absence of CMC.

As specific examples of the dispersant, anionic, cationic, nonionic surfactants, polymer surfactants and the like are known. For example, as the anionic surfactant, alkyl sulfate (such as dodecyl sulfate), alkylbenzene sulfonate (such as dodecylbenzene sulfonate), alkylnaphthalene sulfonate (such as iso-propylnaphthalene sulfonate), etc. However, cationic surfactants such as alkylbenzene trialkylammonium salts (for example cetyltrimethylammonium salt), nonionic surfactants as polymer dispersants, polyvinyl alcohol, polyvinylpyrrolidone, styrene-acrylate copolymers. , Maleic acid (salt) -styrene copolymer, isobutylene-itaconic acid (salt) copolymer, water-soluble cellulose derivative (for example, hydroxyalkyl cellulose, carboxyalkyl cellulose salt, etc.) and the like. Further, examples of the inorganic dispersant include tricalcium phosphate, silica, alumina and the like. Particularly, tricalcium phosphate is preferable.

(Monomer) The ethylenically unsaturated monomer used in the present invention can be freely selected as long as it is radically polymerizable. For example, monovinyl aromatic monomer,
(Meth) acrylic acid ester monomer, vinyl ester monomer, vinyl ether monomer, monoolefin monomer, diolefin monomer, halogenated olefin monomer, polyvinyl monomer The body etc. are mentioned.

Examples of vinyl aromatic monomers include:
Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-butylstyrene, pt-butylstyrene, p-hexyl Styrene, p-
Octyl styrene, p-nonyl styrene, p-decyl styrene, p-dodecyl styrene, 2,4-dimethyl styrene, 3,4-
Examples thereof include styrene monomers such as dichlorostyrene and derivatives thereof. As the acrylic monomer, 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, γ-aminopropyl acrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylamino methacrylate Ethyl etc. are mentioned.

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

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

As the olefinic monomer, ethylene,
Propylene, isobutylene, 1-butene, 1-pentene, 4-
Examples thereof include mono-olefin type monomers such as methyl-1-pentene and di-olefin type monomers such as butadiene, isoprene and chloroprene.

Further, a crosslinkable monomer may be added to improve the characteristics of the polymer particles. Examples of the crosslinkable monomer include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate and diallyl phthalate.

The monomers of the present invention can be used alone or in combination of two or more depending on the purpose. Further, if necessary, a water-soluble monomer, an ionic monomer, or a monomer having a functional group can be used. The added monomer used in the seed polymerization of the present invention may be the above-mentioned monomer. At this time, it may be the same as or different from the monomer unit constituting the seed particles.

The addition amount of the monomer used for seed polymerization can be freely selected within the range where the particle size distribution is not widened. In order to suppress the generation of new particles, it is necessary to add it within a range not exceeding the critical amount shown by the following formula.

Formula V _m / S _a = 6.869 × 10 ^-7 However, in the above formula, V _m represents the monomer volume (critical amount) that can be added to the polymer particle dispersion without generation of new particles, and S _a represents the total surface area of the polymer particles in the polymer particle dispersion liquid.

If the addition amount satisfies this condition, it is possible to generate larger particles by repeating the seed polymerization. The critical addition amount in the seed emulsion polymerization is also applied when the solid component to be composited is compounded in the seed emulsion polymerization process and then the seed emulsion polymerization is performed again to completely encapsulate the component. It is possible to carry out the seed emulsion polymerization again from the state of being fixed or embedded on the surface of the polymer particle to the state of being completely taken into the inside of the particle and the component not being exposed on the surface. When it is not preferable that these solid components appear on the particle surface, for example, when carbon black (abbreviated as CB), which is a pigment in an electrophotographic toner, is present on the particle surface, frictional charging with a carrier is prevented. Even if it does, electric charge leakage may occur due to the CB conductivity on the surface. In this case, it is preferable to completely enclose the particles inside the particles, and this can be achieved by repeating the seed emulsion polymerization again. On the other hand, examples in which the solid component is preferably exposed on the surface of the particles include, for example, fixability improvers. In this case, the desired structure can be obtained by adding it in the final seed emulsion polymerization process.

(Polymerization Initiator) The radical polymerization initiator used in the present invention can be appropriately used if it is water-soluble.
For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4'-azobis-4-cyanovaleric acid and its salts, 2,2'-azobis (2-amidinopropane) salt, etc.), per Examples thereof include oxide compounds.

Further, the above water-soluble radical polymerization initiator can be used as a redox initiator in combination with a reducing agent, if necessary. By using the redox type initiator, the polymerization activity can be increased and the polymerization temperature can be lowered, and further shortening of the polymerization time can be expected.

As the polymerization temperature, any temperature may be selected as long as it is at least the minimum radical generation temperature of the polymerization initiator, but for example, the range of 50 ° C. to 80 ° C. is usually used. However, it is also possible to carry out the polymerization at room temperature or lower by using a combination of a polymerization initiator which starts at room temperature, for example, hydrogen peroxide-reducing agent (ascorbic acid etc.).

(Seed Polymerization Production Step) In the seed polymerization of the present invention, the step of adding a monomer in an amount not more than the critical monomer amount to the seed particle dispersion, the step of uniformly agitating the added monomer in the dispersion, and the step of raising the temperature to the polymerization temperature are carried out. The process consists of heating and adding an initiator and polymerizing. The polymer particles having the required particle size can be easily obtained by repeating the above step once or more.

(Stirring speed) The stirring speed in seed emulsion polymerization is generally 0.40 to 1.05 m / se with respect to the peripheral speed as the steady stirring speed.
It is selected in the range of c, preferably 0.47 to 0.92 m / sec.

The secondary stirring speed is 1.2 to the steady stirring speed.
A stirring speed range of 5.0 times is selected and more preferably 1.25.
A stirring speed in the range of ~ 3.5 times is selected.

The time for maintaining the secondary stirring speed is 5 to 90.
Minutes, preferably in the range of 10-75 minutes.

In the seed emulsion polymerization, the time when the steady stirring speed is increased to the secondary stirring speed is performed when the aqueous dispersion of the specific solid component is added. The addition timing of the aqueous dispersion of the specific solid component is selected within the range of 20 to 85% when the polymerization conversion rate of the seed emulsion polymerization is 100% when the polymerization conversion rate upon completion of the polymerization is 100%. Preferably a time point in the range 35-70% is selected. This is a problem that if the specific component is added immediately after the initiation of the polymerization of the seed emulsion polymerization, it is extremely unstable and easily aggregates, and conversely, if it is added in the latter stage of the polymerization, it is difficult to form a complex with the component.

(Holding Time of Secondary Stirring Speed) The holding time of the secondary stirring speed is appropriately selected as desired, and is, for example, 5 to 1
20 minutes, preferably 10-90 minutes. If the secondary stirring time is maintained for a short time, the solid component and the polymer particles are not sufficiently complexed, and agglomeration easily occurs over a long time.

(Aqueous Dispersion of Solid Component) Examples of the solid component include colorants (inorganic or organic pigments) for electrophotographic toners, charge control agents, and fixability improvers. It is possible to obtain an aqueous dispersion by carrying out fine particle dispersion by means of a physical dispersion method, such as a stirring method, an ultrasonic dispersion method, a solvent dissolution precipitation method, a pH adjustment method and the like. Further, it can be used by dispersing it in water using a known low molecular weight or high molecular weight dispersant. At this time, combination with the above-mentioned physical dispersion method is a preferred embodiment for improving the dispersibility. Further, in the method using a dispersant, it is not preferable to use a dispersant in a necessary amount or more, for example, in the case of a surfactant, it is not preferable to disperse at a critical micelle forming concentration (CMC) or more. This is because the added ethylenically polymerized monomer is taken into the activator micelle, and there is a concern that new particles will be generated. Therefore, when a commercially available dispersion liquid of the above solid component is used, it is necessary to remove the dispersant by using a known method such as dialysis or ultrafiltration. Further, in the case of polyolefin known as a fixing property improver, it is possible to obtain an aqueous dispersion liquid by dissolving the polyolefin itself at a high temperature and further dropping it into water maintained at a high temperature where high speed stirring is performed. Further, a commercially available aqueous dispersion can be used.

The dispersant preferably has a critical micelle formation concentration or higher when the solid component is dispersed, and preferably has a critical micelle formation concentration or lower at the time of addition when added during seed polymerization. Thereby, the generation of new particles is remarkably suppressed and the monodispersity can be maintained.

Specific examples of the dispersant include dodecylbenzene sulfonate, dodecyl sulfate, cetyl trimethyl ammonium salt, polyvinyl alcohol and the like.
An anionic surfactant is preferably used. This is because the components can be sufficiently atomized as desired for the complexation of the present invention. From another aspect, like polymeric dispersants, those that are adsorbed on the surface of particles and cannot be easily removed are problematic to apply depending on the purpose of their use. For example, it is possible to prepare an added dispersion liquid by only ultrasonic dispersion.

For example, in the case of an electrophotographic toner, when a polymer dispersant is used, it is difficult to remove it from the particle surface and the environmental dependency such as the charge amount becomes large, so that it cannot be used. Also, in the case of carrying an immunologically active substance (for example, an antigen, an antibody, a receptor, etc.) on the particle surface by a physical adsorption method as an immunoassay carrier, it is important that the surface is hydrophobic.

The zeta potential of the solid component and the zeta potential of the polymer particles need not be opposite potentials at all. For example, even if the solid component is dispersed with an anionic surfactant and the seed emulsion polymer particles have a negative charge, there is no problem at all. Of course, the opposite charges may be used.

(Electrophotographic Toner) When used as an electrophotographic toner, it is useful not only as a binder resin for pulverized toner but also as a polymerized toner.

When the polymer particles of the present invention are used as a toner for electrophotography, it is necessary to contain a component to be added as a toner in the polymer. Examples of the above components include a colorant, a charge control agent, and a fixing property improver. For example, pigments are achieved by incorporating the desired content during seed particle preparation. Of course, other components can be introduced into the polymer particles as well.

(Colorant) As the colorant, dyes and pigments are generally used, and pigments having high weather fastness are widely used. Examples of the pigment include black pigments such as carbon black and graft-treated carbon black, and color pigments.

As the cyan or green pigment, CI pigment blue 15, CI pigment blue 15: 2, CI pigment blue 15: 3, CI pigment blue 16, CI
Pigment Blue 60, CI Pigment Green 7 and the like.

As the magenta or red pigment, CI pigment red 2, CI pigment red 3, CI pigment red 5, CI pigment red 6, CI pigment red CI. Pigment red 7, CI pigment red 15, CI pigment red 16, CI pigment Red 48: 1, CI Pigment Red 53: 1, CI Pigment Red 57: 1, CI Pigment Red 122, CI Pigment Red 123, CI Pigment Red 139, CI Pigment Red 144, CI Pigment Red 149, CI Pigment Red 166, CI. Pigment Red 177, CI Pigment Red 178, CI Pigment Red 222 and the like.

As yellow or orange pigments, CI pigment yellow 12, CI pigment yellow 13, CI
Pigment Yellow 14, C Pigment Yellow 15, CI
Pigment Yellow 17, CI Pigment Yellow 93, C.
I. Pigment Yellow 94, CI Pigment Yellow 13
8, CI Pigment Orange 31, CI Pigment Orange 43 and the like.

A substance having magnetism, a so-called magnetic substance, can also be used as the coloring agent.

Examples of the magnetic substance include powders of ferromagnetic metals such as iron, cobalt and nickel, and powders of metal compounds such as magnetite, hematite and ferrite.

These magnetic materials can be used in combination with the above-mentioned pigments or alone.

Further, these pigments and magnetic materials can be used in combination with known dyes.

These organic and inorganic pigments may be used alone or in combination as required. This is selected to produce the desired shade.

The content of the pigment in the polymer is 0.5 to 100%
Used in the range of. It is more preferably 1 to 50%.
Further, it is optional to set a desired content as needed. The surface of the pigment used may be surface-treated for the purpose of improving the dispersibility in the polymer particles. By making the surface of the pigment lipophilic using a known surface treatment agent such as a silane coupling agent, the affinity for the monomer is improved and the dispersibility of the pigment in the polymer particles can be improved.

(Fixability Improving Agent) As the fixability improving agent,
Known ones are used. Generally, a polyolefin type is used. For example, low-molecular-weight polyethylene, low-molecular-weight polypropylene, oxidized polyethylene and polypropylene, acid-modified polyethylene, and polypropylene are used. These can be introduced into polymer particles by a conventional method, after being melted, dispersed in water and added in the form of emulsion during emulsion polymerization or seed emulsion polymerization. It is preferable to add it during seed emulsion polymerization so that it can be made to exist as polyolefin fine particles on the particle surface, which is preferable from the viewpoint of improving fixability.

Further, natural wax and polyethylene wax emulsion (“HYTEC”; manufactured by Toho Chemical Industry Co., Ltd.) can be used for the same purpose.

(Charge Control Agent) A charge control agent having a known structure is also used. However, it may not be necessary when the monomer having a polar group is copolymerized on the surface of the polymer particles. The polar group as used herein refers to a group having a charge regardless of whether it is positive or negative, such as a carboxyl group, a sulfonic acid group, an amino group, or an ammonium base.

As the charge control agent, a nigrosine-based electron-donating dye, a metal salt of naphthenic acid or a higher fatty acid, an alkoxylated amine, a quaternary ammonium salt, an alkylamide, a metal complex, a pigment, or a fluorine treatment is used as a positive charge agent. Examples thereof include electron-accepting organic complexes having negative chargeability such as activators, chlorinated paraffins, chlorinated polyesters, and sulfone amines of copper phthalocyanine. Further, chrome yellow, aniline blue, azo type metal-containing dyes and the like can be mentioned.

(Carrier for Immunological Diagnostic Agent) The polymer particles of the present invention are useful as a carrier for immunological diagnostics because of their uniform particle size and the fact that the particle surface is not contaminated by foreign substances. Be done.

As a carrier for immunological diagnosis, it is necessary to immobilize an immunologically active substance such as an antigen, an antibody or a receptor on the particle surface. Physical immobilization methods and chemical immobilization methods are known for immobilization of immunologically active substances.
The former is a method of physically adsorbing and immobilizing it on a hydrophobic surface. For example, by using polymer particles using styrene and its derivatives, acrylic acid ester, methacrylic acid ester, etc., it is possible to easily and immunologically. Active site eg (Fa
b) 'can be immobilized in a form that does not adsorb. As a matter of course, when IgG is used as the antibody, (Fab ′) ² or Fab ′ obtained by digesting the Fc fragment can also be used.

Further, in the case of the chemical immobilization method, the polymer particles of the present invention obtained by copolymerizing a polymerizable monomer having a functional group such as a carboxyl group, an amino group and a thiol group are used,
It is possible to immobilize it by covalent bonding by reacting an immunologically active substance using a known bifunctional reagent. At this time, the polymerizable monomer having the functional group may be added as a comonomer during seed polymerization. The amount of the functional group-containing monomer can be appropriately determined according to need, but it is preferably selected from the range of 0.1 to 15%, for example.

As the antibody to be used, a polyclonal antibody or a monoclonal antibody can be appropriately selected, but a polyclonal antibody is preferable when used in an agglutination test or an agglutination inhibition test. When using a monoclonal antibody, it is preferable to use a mixture of several antibodies having different binding sites for the antigen.

[0064]

EXAMPLES The present invention will be described in detail with reference to examples.

Example 1 (Synthesis of Seed Latex Particles) A cylindrical separable flask having an internal volume of 500 ml was equipped with a temperature sensor, a nitrogen introducing tube, and a stirring device.
A polymerization reactor equipped with (a disk turbine type stirring blade) and equipped with four baffle plates inside the flask was prepared. 29.12 g of distilled styrene monomer was added to 318 ml of degassed ion-exchanged water, and the temperature inside the flask was raised to 70 ° C. while stirring at a stirring speed of 200 rpm in a nitrogen stream. When the internal temperature had risen to 70 ° C., an initiator aqueous solution prepared by dissolving 1.62 g of potassium persulfate in 50 ml of degassed deionized water was added to initiate polymerization.

While maintaining this state, polymerization was carried out for 7 hours to complete the reaction. The produced latex particles were measured with a laser diffraction particle size measuring device SALD-1100 (manufactured by Shimadzu Corporation), and the average particle size d ₅₀ = 0.67 μm and the CV value (σ d ₅₀ / d ₅₀ ) 0.
It was 21. These particles were used as seed particles (1).

Further, instead of styrene monomer, styrene
Polymerization was carried out with the same formulation except that a monomer mixed solution of 24.75 g and butyl acrylate 4.37 g was added. As a result, the average particle size d _{50 was} 0.67 μm, and the CV value was 0.20. This particle was used as a seed particle (2).

(Compounding of solid components during seed emulsion polymerization) (Preparation of aqueous pigment dispersion) Pigments such as carbon black (Regal 330R; Cabot Corporation, USA), Pigment Yellow 17 (KET Yellow 403; Dainippon Ink and Chemicals Incorporated)
Co., Ltd., Pigment Pink 122 (KET Red 309; Dainippon Ink and Chemicals, Inc.), Pigment Blue 15: 3 (KET Blue 10)
4; Dainippon Ink and Chemicals, Inc. was selected and dispersed using an ultrasonic disperser. The pigment aqueous dispersion is 10 g of pigment,
After mixing 0.16 g of sodium dodecylbenzene sulfonate and 90 ml of degassed deionized water, disperse using an ultrasonic disperser to measure the average particle size (d ₅₀ ) and dispersity (CV = σ ₅₀ / d ₅₀ ). did. The results are shown in Table 1.

[0069]

[Table 1]

Using the above dispersion, a pigment and polymer particles were compounded in the process of seed emulsion polymerization according to the following formulation.

(Compounding with Pigment in Seed Emulsion Polymerization Process) Using a polymerization reaction device similar to the synthesis of seed particles,
Prepare a fixed amount of seed particles (1), add 29.1 g of styrene and 168 ml of degassed deionized water, and add a constant stirring speed (Nr
50 ml of deionized water degassed with 1.62 g of potassium persulfate after the internal temperature of the reactor was raised to 70 ° C while stirring in 1).
An aqueous solution of a polymerization initiator dissolved in was added to start seed emulsion polymerization. The pigment dispersion was added after a lapse of a certain time after the start of the polymerization, and at the same time, the secondary stirring speed (Nr2) was increased, and in this state, the stirring speed was lowered to Nr1 for a certain time, and finally the polymerization was carried out for 7 hours. The average particle size (d ₅₀ ) and CV value (σ ₅₀ / d ₅₀ ) were measured from the scanning electron micrograph of the particles thus produced. The results and the polymerization state are shown in Table 2.

[0072]

[Table 2]

From the above results, it is clear that the particles within the scope of the present invention produce very stable composite particles, but they do not aggregate or form no composite in a region outside this range. Further, it is apparent that the produced composite particles have a uniform particle size distribution with extremely high monodispersity.

Further, when the amount of the monomer added in the seed emulsion polymerization was added in excess of the critical amount, new particles were produced, sufficient complexation did not occur, and further, some aggregation was observed.

Example-2 The seed particles (1) of Example-1 above were replaced by (2),
Further, the addition monomer was changed from styrene to 24.8 g of styrene and 4.3 g of butyl acrylate, and compounding was similarly performed under the following conditions. The results are shown in Table 3 below.

[0076]

[Table 3]

As is clear from the results shown in Table 3 above, the method of the present invention enables stable composite formation even when the monomer composition is changed, and the particle size distribution of the produced particles is extremely narrow.

Example-3 Particles (5), (9), (1) of the present invention prepared in Examples-1 and 2
0), (15), (16), (17), (18) particle solids content 7.3g to (5),
(16), (17) is styrene 15g, other is styrene 12.75g,
2.25 g of butyl acrylate was added, the amount of the initiator of Examples 1 and 2 was added and no pigment was added, and seed emulsion polymerization was carried out at 70 ° C. for 7 hours with the stirring speed kept at 200 rpm to coat the pigment with the polymer. did. These are particles of the present invention (20), (2
1), (22), (23), (24), (25), (26). The particle size and CV value of these are shown in Table 4 below.

[0079]

[Table 4]

As is clear from Table 4 above, the monodispersity of the particles of the present invention does not change at all even when the seed emulsion polymerization is carried out again. Observation of these particles with a scanning electron microscope revealed that the pigment did not appear on the surface of the particles.

Example-4 Using the particles (15) of the present invention prepared in Example-2, an acid-modified polypropylene was made into a 10% aqueous dispersion according to a conventional method.
(Average particle size: 0.18 μm) and charge control agent Bontron E-81
Was prepared as a 10% aqueous dispersion (average particle size: 0.09 μm).

To the polymerization reactor described in Example 1, 7.3 g (10% aqueous dispersion) of the particles of the present invention as solid matter was added 168 ml of degassed deionized water, and the stirring speed was 200 while nitrogen was flowing.
Stir at rpm and add 12.75 g styrene and 2.2 butyl acrylate.
5g was added. When the monomer became uniform, the internal temperature of the reactor was raised to 70 ° C., and 1.62 g of potassium persulfate dissolved in 50 ml of degassed deionized water was added to the polymerization initiator aqueous solution. After 3 hours from the addition, 2.2 g of the acid-modified polypropylene dispersion was added, the secondary stirring speed was set to 600 rpm and maintained for 15 minutes, the steady stirring speed was again lowered to 200 rpm, and the reaction was carried out for 7 hours after the initiation of the polymerization to complete the polymerization. On the other hand, with the same formulation, an acid-modified polypropylene aqueous dispersion and a Bontron E-81 aqueous dispersion were simultaneously prepared.
The same operation was performed after adding 2.25 g.

The former was used as the particles (27) of the present invention, and the latter was used as the particles (28) of the present invention. The results are shown in Table 5 below.

[0084]

[Table 5]

It can be seen that the particles of the present invention produce stable particles and have a remarkably narrow particle size distribution even when another specific component is compounded during the seed emulsion polymerization again. Furthermore, it was found by observation with a scanning electron microscope that the fixability improver had a head on the particle surface and formed a microdomain.

Example-5 Particles of the present invention (15), (17), (23), (24), (25), (26), (27), (2
Using 8), various conditions were changed in accordance with the description of JP-A-60-220358 to carry out association and fusion. The average particle size d ₅₀ (μm), particle size distribution (σ ₅₀ / d ₅₀ ) and the degree of indefiniteness of each amorphous particle were measured. The results are shown in Table 6 below.

[0087]

[Table 6]

2 wt% of silica and 1 wt% of titanium oxide were added to and mixed with the above-mentioned colored amorphous particles (1) to (17),
5 parts of this externally added toner and 95 parts of ferrite particles (carrier) surface-coated with a methyl methacrylate / styrene copolymer were mixed to prepare the developers (1) to (17) of the present invention.

Styrene / butyl acrylate for comparison
-85/15 (wt%) Mw = 6.8 × 10 ⁴ , carbon black content 8 wt% and polypropylene wax 3 wt% were kneaded and pulverized to prepare toners having an average particle diameter of 5.2 μm and 8.3 μm. The degree of indefiniteness of this toner is 2.89 and 2.67, respectively, and according to the method for synthesizing colored particles-5, a spherical toner having an indefinite degree of 1.03 with an average particle diameter of 5.3 μm is synthesized, and similarly, the comparative developer is used. Prepared as (1) to (3).

An electrophotographic copying machine "U-Bix" using the above developer and equipped with a heat roller fixing device and a cleaning blade.
3032 ”(manufactured by Konica Co., Ltd.) was subjected to a live-action test in which a copy formed an image, and the following items were evaluated.

(1) Resolution A copy image of a thin line chart was formed and judged by the number of distinguishable thin lines per 1 mm.

(2) Fogging Copy images are continuously formed in a normal temperature and normal humidity environment (temperature 20 ° C., relative humidity 60%), and the “Sakura Densitometer PDA-6
0 ”(manufactured by Konica Corp.) was used to measure the reflection density of each color in the white background portion, and the fog was judged by the number of copies when the reflection density exceeded 0.02.

(3) Offset Occurrence Temperature The preset temperature of the fixing roller is changed stepwise to form a copy image, and the preset temperature of the fixing roller at the time when toner stain due to hot offset occurs is measured and shown. It was

(4) Coloring Degree of Toner A single layer of toner was attached to a white label, and this toner layer was measured for reflection density for each color using a "Sakura densitometer PDA-60". A value of 1.3 or less was marked with x.

(5) Cleaning Property The surface of the photoconductor was visually observed and evaluated by the number of copies when the cleaning failure occurred.

(6) Change in particle size distribution Evaluation was made by the change in the number% of toner particles having a volume average particle size of 1/3 or less. In the actual copying test, the particle size distribution was measured over time, and it was shown that the number% of the toner was 1/3 or less of the volume average particle size at the start, at the time of fogging, and at 50,000 copies. A laser diffraction particle size distribution analyzer SALD-1100 (manufactured by Shimadzu Corporation) was used for the measurement. The results are shown in Table 7.

[0097]

[Table 7]

From the above results, when the degree of indefiniteness of the developer of the present invention increases, the cleaning property deteriorates a little and fine powder is generated, but there is no serious problem. On the other hand, the kneading and pulverization method of the comparative developer causes early occurrence of fogging and poor cleaning. Further, it is apparent that the true spherical toner is remarkably inferior in cleaning property.

As is clear from Table 7 above, the polymerized toner of the present invention is a good toner that not only has performance comparable to that of the kneaded and pulverized toner, but also has a small change in particle size distribution in the actual copying test. I know there is something. In particular, it is known that if the number% of toner particles having a volume average particle diameter of 1/3 or less exceeds 10%, the charging property of the toner is hindered. From this point, it is apparent that the polymerized toner of the present invention is more stable than the comparative toner.

Example-6 The colored particles (22) of the present invention prepared in Example-3 were prepared as immunodiagnostic particles according to the following formulation. Colored particles of the present invention S-
After 09 was added and dialyzed against pure water for 24 hours, it was concentrated to a solid content of 5% using an ultrafiltration device. After repeating this operation 5 times to make it completely clean,
Add 0.1 mol / l phosphate buffer and sodium chloride,
The cells were suspended in 1M PBS.

An anti-α-fetoprotein antibody (IgG fraction) was added to this dispersion, and physical adsorption was carried out at 4 ° C. for 24 hours. Then, put it in a cellulose dialysis bag with a molecular weight cutoff of 200,000 and dialyz it with 0.1 mol / l PBS at 4 ° C for one day to remove unadsorbed IgG.
Was concentrated to. 0.1M so that the solid content becomes 0.2%
Diluted with PBS (pH = 7.2).

This was used as the immunoassay reagent of the present invention. As a sample for comparison, Fujirebio Co., Ltd.'s Therodia AFPmo
Using no, purified human α-fetoprotein (manufactured by Dako) was used as a sample and the dilution series was 100 with 1000 ng / ml as mother liquor.
0,500,250,125,62.5,31.25,15.63,7.81ng / ml was prepared. 25 μl of each AFP solution and 25 μl of the latex reagent were separated, mixed in a microplate and allowed to stand for 1 hour to observe the aggregates. The results are shown in Table 8.

[0103]

[Table 8]

However, in the table, (+) indicates that aggregation is positive, (−) indicates negative, and (±) indicates that determination cannot be made.

As described above, it is clear that the immunoassay reagent of the present invention does not show the prozone phenomenon even in the high concentration region and exhibits stable performance.

[0106]

By the constitution of the present invention, a composite polymer particle which is monodisperse and whose particle size can be freely controlled can be obtained. These composite polymer particles are suitable as a toner exhaustion and folding carrier for electrophotography.

Claims (11)

[Claims] 1. An ethylenically unsaturated monomer which is the same as and / or different from the ethylenically unsaturated monomer unit constituting the polymer particles is added to a polymer particle dispersion liquid containing substantially no dispersant. In the presence of a water-soluble radical polymerization initiator, with respect to monodispersed and large-sized polymer particles obtained by seed polymerization, the polymerization conversion rate of seed polymerization is 20 to 85%, and the aqueous dispersion of the solid component is added. A monodisperse composite polymer particle with a solid component characterized by accelerating from a constant stirring speed to a constant secondary stirring speed after addition, stirring at the speed for a certain period of time, and then returning to the constant stirring speed for polymerization. .. 2. The polymer particles subjected to the seed polymerization are:
The composite polymer particle according to claim 1, which is a polymer particle produced by at least one polymerization method of emulsion polymerization, suspension polymerization, and dispersion polymerization. 3. The composite polymer particle according to claim 1, wherein at least 50% by weight or more of the ethylenically unsaturated monomer added is a hydrophobic ethylenically unsaturated monomer. .. 4. The composite polymer according to claim 1, wherein the added amount V _m of the ethylenically unsaturated monomer to be added is not more than the critical amount represented by the following formula. particle. Formula V _m = S _a × 6.869 × 10 ⁻⁷ (however, V _m : critical addition amount of monomer, S _a : total surface area of seed particles) 5. The secondary stirring speed is 1.2 which is a steady stirring speed.
5. The composite polymer particle according to any one of claims 1 to 4, which has a speed range of from 5.0 to 5.0 times. 6. The monodispersion with the solid component according to claim 1, wherein the solid component is selected from a colorant and / or a charge control agent and a fixing property improver. Composite polymer particles. 7. An ethylenically unsaturated monomer, which is the same as and / or different from the ethylenically unsaturated monomer unit constituting the polymer particles, is added to a polymer particle dispersion liquid containing substantially no dispersant. In the presence of a water-soluble radical polymerization initiator, with respect to monodispersed and large-sized polymer particles obtained by seed polymerization, the polymerization conversion rate of seed polymerization is 20 to 85%, and the aqueous dispersion of the solid component is added. After the addition, to the composite polymer particles obtained by polymerizing by returning from the constant stirring speed to a constant secondary stirring speed and stirring for a certain period of time at the speed and then returning to the constant stirring speed after addition,
Obtained by seed emulsion polymerization in the presence of a water-soluble radical polymerization initiator by adding an ethylenically unsaturated monomer which is the same as and / or different from the monomer unit constituting the polymer in a critical amount or less satisfying the following formula: Particles of a monodisperse composite polymer containing a solid component contained therein. Formula V _m = S _a × 6.869 × 10 ⁻⁷ (however, V _m : critical addition amount of monomer, S _a : total surface area of seed particles) 8. An electrophotographic toner using the monodisperse composite polymer particles according to any one of claims 1 to 7. 9. An immunoassay carrier using the monodisperse composite polymer particles according to any one of claims 1 to 7. 10. A step of a) adding an ethylenically unsaturated monomer unit to an aqueous dispersion of polymer particles containing substantially no dispersant to make the mixture uniform, and b) raising the temperature to a polymerization initiation temperature to carry out radical polymerization. Step of adding aqueous initiator solution c) Step of adding aqueous pigment dispersion at a polymerization conversion rate of 20 to 85% d) Accelerating the stirring speed from a steady stirring speed to a secondary stirring speed for a certain period of time. And the solid component is coordinated and fixed on the surface of the polymer particles. E) The stirring speed is returned to the steady stirring speed, and the polymerization is completed at a constant polymerization temperature. A method for producing large-diameter monodisperse composite polymer particles. 11. A step of a) adding an ethylenically unsaturated monomer unit to an aqueous dispersion of polymer particles containing substantially no dispersant to make the mixture uniform, and b) heating to a polymerization initiation temperature to carry out radical polymerization. Step of adding aqueous initiator solution c) Step of adding aqueous pigment dispersion at a polymerization conversion rate of 20 to 85% d) Accelerating the stirring speed from a steady stirring speed to a secondary stirring speed for a certain period of time. And the solid component is coordinated and fixed on the surface of the polymer particles. E) The stirring speed is returned to a steady stirring speed to complete the polymerization at a constant polymerization temperature. F) Furthermore, for the composite polymer particles, A method for producing monodisperse composite polymer particles encapsulating a solid component, which comprises a step of performing seed emulsion polymerization by adding a critical amount of an ethylenically unsaturated monomer and a water-soluble radical polymerization initiator. ..