JPS627429A - Method for obtaining colloidal particle aggregate - Google Patents

Abstract

PURPOSE:To obtain a most closely-packed aggregate in a non-fused state, by separating flocculated particles from aqueous particulate colloid and drying the same in such a state that the temp. of the flocculated particles is held to temp. lower than the softening temp. of colloidal particles or heating the same in an aqueous phase in the same state. CONSTITUTION:A flocculant is added to aqueous particulate colloid at temp. lower than the fusing and uniting temp. of colloidal particles and the flocculant unit is allowed to be present in hydrophobic particulate colloid in a studded state before the flocculant is dissolved and diffused in the hydrophobic particulate colloid. Then the colloidal particles are flocculated around the flocculant unit so as to present on the outer surface thereof and flocculated particles are grown from the interior to the exterior. These flocculated particles are separated from the hydrophobic particulate colloid and dried or heated in an aqueous phase in such a state that the temp. thereof is held to temp. lower than the softening temp. of colloidal particles and a most closely-packed spherical colloidal particle aggregate is obtained in such a state that colloidal particles are not fused and adhered thereto.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention utilizes aggregation reactions and coagulation reactions of aqueous colloid particles to produce regularly arranged full-body particles, which are then separated from aqueous particle colloids. The present invention relates to a method for producing a close-packed colloidal particle aggregate by removing water inside the particles.

The aqueous particle colloid referred to here is a particle that can be treated as a solid or gel with an aqueous phase as a dispersion medium, and the dispersed phase is a liquid in which the dispersed phase is charged and suspended in the aqueous phase. It refers to a liquid that can be coagulated and coagulated by adding a coagulant. Naturally, it also includes polymer latex obtained by emulsion polymerization.

"Prior Art and Problems" Conventionally, as a method for recovering 31 coid particles from aqueous particle colloids, whether natural or artificial, since the basic particles are extremely minute, it has been necessary to form a combination of these particles and then It is common to use a process for refining, refining, and drying. Although this type of technology is not limited to polymer latex, we will explain polymer (synthetic resin) latex, which is a typical aqueous colloid particle for which this technology is difficult to apply due to its low softening temperature.

When recovering the resinous polymeric polymer, which is the dispersed phase, from polymer latex, generally an aqueous solution of coagulants such as inorganic salts and acids is added to the latex, or conversely, the latex is added to coagulant water/8 liquid. The slurry is solidified in a liquid phase, made into a slurry by heat treatment, etc., and then dehydrated and dried to obtain powder. However, in the case of this method, the shape of the powder is amorphous, the powder particle size is difficult to adjust, the particle size distribution is wide, and a considerable amount of fine powder is included. As a result, undesirable results have occurred, such as loss due to scattering, frequent troubles in the process due to clogging with fine powder, deterioration of the working environment due to dust generation, and increased risk of explosion due to dust. In addition, because it is difficult to control the bulk density of the powder, transportation costs, safe storage fees, etc. increase, and the dehydration, drying, fluidity, blocking resistance, etc. dehydration·
Drying equipment was needed.

Extremely intense efforts have been made in the field of synthetic resin manufacturing to improve these problems. A method has been proposed in which spherical coagulated particles are recovered by absorbing coagulated particles into an organic solvent, removing the solvent, and solidifying the coagulated particles. The background to the development of these various recovery methods is that the value of cherished products is increasingly influenced by the quality of the properties such as the distribution, size, and filling rate of the powder rather than the physical properties of the polymer itself. There are trends of the times.

In the former method, large particles of 500 μm or more can be produced and 8
The production of highly heat-resistant polymers with a softening temperature of 0°C or higher has the disadvantages that it is difficult to use them industrially and that it is difficult to tightly pack the inside of the particles. In addition to the difficulty of removing substances and densely packing the inside of particles, problems such as cost, quality, range of application, particle characteristics, etc. have been raised, such as the lack of organic solvents that can be used with this method depending on the type of polymer. There is.

On the other hand, spray drying and vacuum granulation drying are methods for directly drying latex to obtain a solid, and many improvements have been made to the equipment. However, with these methods, it is difficult to remove components contaminated in latex, and in addition to requiring larger equipment when producing large particles, low-concentration latex requires a large amount of thermal energy. There are significant constraints in terms of quality and cost, such as increased processing costs. A common problem with these conventional methods is that it is difficult to remove impurities from the latex, and it is difficult to dissolve the dried and collected powder in a solvent, redisperse the latex particles in a dispersion medium, or When gelling with a processing molding machine,
It may be difficult to work quickly, or to achieve homogeneous dispersion or gelation.

"Means for Solving the Problems" The present invention is a method developed for the purpose of solving the above-mentioned drawbacks all at once.

That is, the present invention provides (A) a temperature at which the colloidal particles fuse together (
(B) adding a coagulant at a temperature lower than the coagulant unit (softening temperature) and interspersing coagulant units in the colloid dispersion before the coagulant dissolves and diffuses into the colloid; By melting and diffusing the coagulant in the colloid, the colloid particles are coagulated on the outer surface of the coagulant unit, and the coagulated particles grow from the inside to the outside. (C) Separate the coagulated particles from the aqueous colloid particles to obtain coagulated particles, and dry or water the coagulated particles while maintaining the temperature of the coagulated particles at a temperature lower than the softening temperature of the colloidal particles. The subject matter is a method for obtaining the previously discussed spherical colloidal particle aggregate in a state where the colloidal particles constituting the coagulated particles are not fused by heating in a phase.

The present invention is applicable to all aqueous particle colloids in which a coagulation reaction is caused by the addition of a coagulant and the colloid particles can be recovered as a solid coagulation.

Here, solid means something that behaves or can be handled as a solid, and naturally rubber-like substances that are elastic bodies and gel-like plastic substances with high viscosity are also included in the applicable range. Even if a solidified material exhibits fluidity at room temperature, it can be applied by operating under cooling if it becomes solid upon cooling. The present invention will be explained by taking polymer latex as an example of an aqueous particle colloid.

The present invention adds a coagulant to latex, suppresses the diffusion of the coagulant into the latex, disperses the coagulant into the latex to create scattered coagulation, and then removes the coagulant from the scattered coagulation. By naturally dissolving and diffusing into the latex, the latex is coagulated mainly through coagulation, and coagulated particles grow from the inside to the outside, and then separated from the latex as coagulated particles, and after drying or This is a method of producing particles by sintering at a high temperature above the softening temperature without drying. The solidified particles thus obtained are spherical particles in which the basic particles constituting the latex are regularly arranged in a crystal lattice.

The coagulant used in the present invention includes a substance that can coagulate latex, or a substance that produces a substance having a coagulation function through a reaction between a substance previously mixed in latex and a newly added substance.

The substance that can be solidified may be in a gaseous, liquid, or solid state. Further, a coagulated slurry obtained by coagulating latex in advance may be used as the coagulant.

In addition, as a reaction, a capsule-shaped composite can be made by using a slurry pre-coagulated using the above-mentioned coagulant as a coagulant for the same or different types of latex. It is also possible to make a capsule-shaped composite by impregnating or mixing the coagulant into a powder prepared in advance and adding it to latex as a coagulant (this method is the same as making the coagulation in advance). .

Coagulants used in liquid or solid state include, for example:
Sodium chloride, potassium chloride, lithium chloride, sodium bromide, potassium bromide, lithium bromide, potassium iodide, potassium sulfate, ammonium sulfate, sodium sulfate,
Ammonium chloride, sodium nitrate, potassium nitrate, calcium chloride, ferrous sulfate, magnesium sulfate, zinc sulfate, copper sulfate, barium chloride, ferrous chloride, magnesium chloride, ferric chloride, ferric sulfate, aluminum sulfate, potassium Inorganic salts such as alum and iron alum, hydrochloric acid,
Inorganic acids such as sulfuric acid, phosphoric acid, nitric acid, inorganic alkalis such as caustic soda, caustic potash, calcium hydroxide, magnesium hydroxide, organic acids such as acetic acid, formic acid, organic acids such as sodium acetate, calcium acetate, sodium formate, calcium formate, etc. These salts are solid, liquid, aqueous solution or f6 solution in a water-soluble organic solvent, either alone or as a mixture. The solid may be dispersed in a sparingly soluble and water-soluble organic solvent and added in the form of a slurry.

The latex that can be the subject of the present invention may be anything as long as it is composed of solid particles that can be recovered. Examples of polymer latexes include the following, which are substantially emulsion polymerized or suspension polymerized. Almost all polymer latexes that can be recovered in the form of resins obtained in

The object may be a single or mixed latex of a polymer obtained by polymerizing, copolymerizing, or graft polymerizing a monomer composition mainly consisting of one or more heptamers selected from the following monomer group. However, it is natural to exclude those that cannot be polymerized. Vinyl aromatics such as styrene, monochlorostyrene, dichlorostyrene, α-methylstyrene; vinyl cyanides such as acrylonitrile, methacrylonitrile; acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate; methyl methacrylate, ethyl methacrylate, butyl methacrylate methacrylic esters such as; vinyl halides such as vinyl chloride, vinyl bromide, and vinyl fluoride; vinylidene halides such as vinylidene chloride and vinylidene bromide; acrylic acid,
Methacrylic acid, itaconic acid, maleic acid, vinyl acetate,
Ethylene, propylene, butylene, butadiene, isoprene, chloroprene; crosslinking monomers such as allyl methacrylate, diallyl phthalate, triallyl annulate, monoethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, divinylhenzene, glycidyl methacrylate.

Further, in the present invention, the following polymer latexes can be particularly preferably used.

(1) 20 to 80 parts of acrylonitrile monomer and 1+ of vinyl chloride, vinylidene chloride, vinyl bromide, vinylidene bromide,! Alternatively, a polymer latex obtained by polymerizing monomers consisting of 20 to 80 parts of a mixture of two or more types and 0 to 10 parts of an easily dyeable additive.

(2) Styrene O ~ 50 wt% (weight %, unless otherwise noted as % of other species, % is -L%), butadiene 50 ~ 1
00% butadiene polymer latex.

(2') (2) 0 to 50% acrylic ester in the presence of 20 to 80 parts of nophtadiene polymer latex,
Methacrylic ester 0-100%, vinyl aromatic 0-9
A polymer latex obtained by polymerizing 20 to 80 parts of monomers consisting of 0% vinyl cyanide, 0 to 90% vinyl cyanide, and 0 to 20% other copolymerizable monomers.

(3) Styrene 0-50%, butadiene 50-100%
, 0-100% of methyl methacrylate, 0-60% of other methacrylic esters or acrylic esters other than methyl methacrylate, 0-60% of vinyl aromatics, in the presence of 0-20 parts of a rubbery polymer latex consisting of 0-30% of acrylic esters. A polymer latex obtained by polymerizing 80 to 100 parts of a monomer consisting of ~90% and 0 to 90% of vinyl cyanide.

(4) Styrene O~50%, butadiene 50~100%
In the presence of ~90 parts of a butadiene-based polymer consisting of,
A graft copolymer obtained by polymerizing 10 to 90 parts of one or more monomers selected from vinyl aromatic, methacrylic ester, acrylic ester, and vinyl cyanide (
A) 0 to 50 parts and α-methylstyrene O to 70 mol%
Polymerization of monomers containing 30 to 100 mol% of one or more monomers selected from vinyl aromatic, methacrylic ester, acrylic ester, acrylic acid, and vinyl cyanide. A mixed latex with 50 to 100 parts of substance (B).

(5) 40-100% acrylic ester, vinyl aromatic, vinyl cyanide, vinyl chloride, vinylidene chloride,
1 selected from vinyl acetate or conjugated diolefins
0 to 60% of the species or two or more monomers, and 0 to 1 of the crosslinking agent
In the presence of 5 to 85 parts of a rubber polymer obtained by polymerizing 0% with 15 to 9 of one or more types of body parts
Polymer latex obtained by 5-part polymerization.

(6) 40 to too parts of vinylidene chloride and one or more selected from vinyl aromatics, vinyl cyanide, acrylic esters, methacrylic esters, acrylic acid, methacrylic acid, itaconic acid, maleic acid, and crosslinking monomers A polymer latex obtained by polymerizing 0 to 60 parts of monomers.

(7) 40 to loo parts of vinyl i-ide, 0 vinyl cyanide
~20 parts and one or more monomers selected from vinylidene chloride, vinyl bromide, vinylidene bromide, acrylic ester, methacrylic ester, acrylic acid, methacrylic acid, itaconic acid, maleic acid, and crosslinking monomers body 0
A polymer latex obtained by polymerizing ~60 parts.

In the present invention, as a first step, a coagulant is dotted into latex without being dissolved. As mentioned above, the coagulation reaction rate is generally extremely fast, so the coagulation reaction occurs in parallel during the process in which the coagulant is dispersed as a unit in the latex.
A coagulum is formed around the outer periphery of the coagulant unit and covers its surface. In addition, the coagulated particles that have partially undergone the coagulation reaction are divided,
It may also become a solidified species when dispersed throughout the latex.

Therefore, even if the coagulant is a liquid or a gas, the scattered coagulation species can actually be considered to be solid particles having the coagulant in the center and the coagulate at the periphery.

Next, in the second step, the coagulant in the center dissolves and diffuses and comes out from the inside through the coagulate layer on the periphery, and at the same time comes into contact with the latex on the outer surface, where a coagulation reaction occurs immediately and latex particles are layered on the outer surface. As a result, coagulated particles gradually grow from the inside.

The key point in implementing the present invention is the first step. That is, in the first stage: (1) As the coagulation rate becomes slower, a coagulation reaction does not occur on the outer surface, but instead diffuses into the latex phase and causes a coagulation reaction.

(2) Furthermore, if the coagulated material layer formed on the outer surface is soft, the coagulated material will easily disperse into the latex phase, where a coagulation reaction will occur.

Both (1) and (2) above lead to coagulation of the entire latex, which is exactly the form of conventional coagulation methods.

Therefore, it is important to set conditions to prevent (1) and (2). If the coagulant is an aqueous solution and the concentration is dilute, both (1) and (2) are likely to occur, so a higher concentration is desirable. In addition, if it is dilute, it is difficult to form coagulant units precisely, so it is necessary to add a thickener to increase the viscosity, or lower the temperature to suppress the dissolution and diffusion into the latex and the coagulation reaction until the units are scattered. Requires some ingenuity. For the above reasons, it is easiest and most reliable to use a solid powder as a coagulant. Particularly when the coagulant is a liquid or gas, the higher the coagulation rate, the easier it is to obtain stable operation. In general, it is easier to use acids and polyvalent metal bases with a large number of coordinations, but conversely, if the coagulation is too rapid, it becomes difficult to disperse coagulated species in the latex. Therefore, it may be necessary to control the concentration of the coagulant in the case of a liquid or by using air, nitrogen, or water-soluble carbon dioxide as a diluent in the case of a gas.

Furthermore, the relationship between the dispersion of the coagulant into the latex and the reaction rate and diffusion rate can be adjusted by adjusting the temperature by cooling the coagulant and adjusting the viscosity by adding a thickener.

The same can be said about latex concentration.

In other words, as the dilution becomes more diluted, unit particles, which are reactants, come less frequently to the outer surface of the coagulated particles, and the coagulant becomes more likely to diffuse into the latex phase, so (1) occurs, and naturally the coagulated layer Since the solid content concentration of is reduced, the coagulated material layer becomes soft, that is, (2) occurs. Therefore, the higher the latex concentration, the more reliably particles can be produced.

Embodiments of the present invention will be described in more detail.

(1) When the coagulant is solid; ■Pour the latex into a beaker and stir.

Add a powdered solid coagulant such as salt, momentarily stir strongly so that it is dispersed in the latex, and then immediately stir gently. This state is maintained for 1 minute to 1 hour, stirring is stopped, and the latex is passed through a mesh sieve to remove coagulated particles. In this case, cool the beaker with ice water or the like as necessary. Also,
If stirring is weak, the coagulant will settle to the bottom, resulting in hemispherical coagulated particles.

■Water-soluble organic solvents such as alcohols and ketones,
A powder dispersion of the coagulant is prepared in an organic solvent that is insoluble or poorly soluble in the coagulant, and this is added to the latex.

(2) When the coagulant is liquid; ■Drop the coagulant into the latex.

■Spray the coagulant into the latex and add it in fine droplets.

(2) When adding a coagulant to the latex at -INL, stir strongly only when adding the coagulant, and after dispersing the coagulant dropwise into the latex, stir gently.

It is desirable to pre-cool the latex and coagulant to reduce the rate of diffusion. No particular cooling is required after dispersion. Adding a thickener to the coagulant is also effective in suppressing diffusion and creating dispersed droplets.

(3) When the coagulant is a gas; The coagulant gas and latex are cooled in advance, and the gas is added near the bottom of the stirring blade and dispersed in the latex with strong stirring.

(4) When the coagulant is slurry-based or solid-impregnated - Usually, the same method as for solids is sufficient.

Note that the slurry form can be, for example, a solidified slurry by adding a diluted coagulant aqueous solution to latex under strong stirring to form random aggregates. In addition, solid-impregnated solid includes, for example, a solid obtained by immersing powder particles in an aqueous coagulant solution, impregnating the particles with the coagulant, and then filtering the particles to remove the aqueous coagulant solution remaining on the surface of the particles.

Further, the stirring during hardening should be moderately strong enough to prevent the coagulation of the coagulated particles from colliding with each other after the coagulated species are scattered in the latex. However, if it is too weak, the coagulated particles will settle and come into contact with each other, resulting in coalescence. Since coagulated particles are constantly growing, they tend to coalesce. If it is too strong, in addition to the coalescence of the coagulated particles, the coagulated particles are destroyed, causing dissolution and diffusion of the coagulant, resulting in a conventional coagulation reaction, resulting in a random combination such as the entire coagulation. Particular care must be taken when the latex concentration is low or when a coagulant with weak coagulating power is used. For this reason, it is desirable that the liquid flow during solidification be in a laminar flow state.

As described above, setting the operating conditions during coagulation is the key to embodying the present invention, so the dispersion rate of the coagulant,
Even if it is not possible to obtain the absolute values of the coagulation reaction rate and the diffusion rate of the coagulant into the latex, it is necessary to understand the relative relationship in advance through experiments. It is essential to know how the behavior of coagulated particle formation and phenomena occurring in latex qualitatively change with changes in operating conditions such as temperature, viscosity, stirring speed, etc.

Further, the particles in the present invention need to be dispersed from the coagulation system in a state in which latex particles, which are the basic particles, are not fused together. Therefore, the coagulation operation must be performed while the temperature of the coagulation system, that is, the entire latex bath, is maintained at a low temperature below the softening temperature of the latex particles. Therefore, in the case of polymeric latexes whose softening temperature is lower than the latex temperature, it is necessary to carry out this solidification operation under cooling.

The coagulated particles obtained in this way have an extremely rapid coagulation reaction that occurs immediately after or partially simultaneously with the first stage of dispersion and dotting of the coagulant into the latex. However, random rough filling parts remain. The size of this random rough filling part tends to be larger as the coagulant has a faster coagulation rate, and when the coagulant is a liquid, the smaller the 1 degree is, the larger it is. Furthermore, if the coagulant is solid, a void remains in the center of the particle, indicating the presence of the solid. In any case,
Since such loosely packed parts and voids in the center of the particle are extremely small compared to the entire particle, the particle can be regarded as a homogeneous charge as a whole.

"Operations and Effects" Although the present invention does not seem to be different from the conventional coagulation method in terms of operation, it is fundamentally different. The essential difference is that the coagulated particles in conventional methods are randomly arranged aggregates of latex particles. Conventional methods can be broadly classified into three types, and will be explained based on these three types of operations.

(1) First, there is a method of coagulating by mixing latex and coagulant, but since the coagulation reaction rate is usually instantaneous,
The melting and diffusion of the coagulant into the latex immediately leads to the phenomenon of coagulation. That is, in conventional methods, an aqueous solution of acids or salts is usually used as a coagulant, and the coagulant is mixed and diffused into latex. As a result, three phenomena occur simultaneously in the coagulation system: mixing of the coagulant and latex, melting and diffusion of the coagulant into the latex, and coagulation of the latex. Since the coagulation reaction rate is usually extremely fast, the phenomena are: 1. A coagulated mass is formed at the contact area between the latex and the coagulant, 2. The coagulated mass is crushed and divided by an external force such as stirring, and 2. In the process, it is mixed with unreacted latex, and all the latex is solidified and divided.

This step is observed. Therefore, the coagulated particles are obtained in the form of a nearly homogeneous slurry dispersed in the aqueous phase, and there is no need to separate the coagulated particles from the latex as in the present invention.

The random aggregates obtained in this way contain a large amount of water and exhibit chicken-tropic fluidity, and do not exhibit liquid-like behavior even when the solids concentration in the slurry is lower than 20%. Adjustments such as adding dilution water are required. When the solid content concentration is extremely small,
A small stirring force is required, and in some cases, a solidified slurry can be obtained using only a water stream.

Furthermore, if the coagulation reaction is to be lower than the dissolution/diffusion rate, a dilute coagulant aqueous solution with weak coagulation power can be added. In this case, after the coagulant reaches a uniform concentration in the latex, the entire product coagulates at the same time. Without stirring, the solidified latex becomes agar-like, but under stirring at 112 degrees, it becomes fine particles similar to individual latex particles. It becomes an aqueous slurry.

(2) Next, there is a method in which the latex is added to the aqueous coagulant solution in the form of dispersed drops or as a streak or band-like fluid using a nozzle or the like.

This method is based on the idea of creating particles by subjecting the latex to a solid reaction in the form of dispersed droplets, or in the case of streaks or bands, in the form of particles separated in a coagulant. At this time, the degree of fragmentation determines the particle size, so the flow strength and temperature of the coagulation liquid must be controlled, but since latex easily disperses in the aqueous phase and the coagulation particle retention force is extremely small, Efforts are taken to increase the holding power by fusing the surface layer of the coagulated particles, such as by raising the temperature above the softening temperature of the latex particles. Therefore, since the coagulation reaction and fusion of the latex particles proceed rapidly and simultaneously, a coagulated body in which the interior of the particles is randomly and loosely filled cannot be avoided.

Naturally, the coagulated particles obtained in (1) and (2) above are amorphous particles with a wide particle size distribution.

(3) Furthermore, there is a method of spraying latex droplets into the gas phase of a coagulating atmosphere to obtain spherical coagulated particles.

This method is an excellent method in which it can be made spherical by utilizing surface tension in order to eliminate the drawback of (2), but it has limitations in the following two points.

(a) Similar to (2) above, this is a problem that occurs when latex rings are coagulated from the outside, and the coagulated particles do not shrink and the excess water that remains inside prevents regular arrangement, leaving voids inside after drying. Live.

(b) When collecting particles by falling them from the gas phase,
Under conditions (for example, low temperature) that make particles more fragile and reduce voids inside them, fine powder is more likely to be generated. Furthermore, the equipment becomes larger and it becomes difficult to produce large particles.

In the conventional methods as described above, it cannot be expected that the recovered coagulated particles will be dried or heated in an aqueous phase to form a structure in which the inside of the particles is tightly packed with latex particles. The reason for this is believed to be that the latex particles constituting the particles are arranged randomly and coarsely packed. The voids herein refer to voids or cavities larger than the basic particles, and do not mean voids smaller than the basic particles that occur in the gaps when the basic particles are packed close-packed without being fused. In this way, (1), (2
), (3) In both conventional methods, the coagulated particles are separated from the aqueous phase, whereas in the present invention they are separated from the latex, which suggests a fundamental difference between the conventional method and the present invention. It is something.

On the other hand, the method of the present invention first creates a state in which a highly concentrated coagulant is scattered in the latex without being dissolved in the latex, and then allows natural diffusion into the latex, thereby preventing the coagulation reaction. The system is dominated by diffusion of the coagulant into the latex. It is thought that by doing so, the unit particles are regularly arranged in the coagulated body.

In addition, when latex particles grow as a coagulate, the latex particles tend to be arranged in a close-packed arrangement with a low energy level, so that the particle density of the coagulate becomes larger than the particle density of the latex. The degree of density depends on the coalescence strength of the unit particles and the degree of time allowance for arrangement. In other words, the latex particles interact with each other by a coagulation reaction.
If the strength of the fusion bond is high upon contact, the latex particles cannot be densely arranged. This is determined by the balance between the softening temperature of the latex particles and the temperature of the coagulation system.

However, since the attractive force between latex particles is only van der Waals force, which is a small force, the degree of dense arrangement is not large even if the coalescence strength is small. In order to increase this level, it is necessary to apply an external force, and specifically, there is a means to control the flow state and create a vortex flow. However, in this case, there is a limit to the size of the particles. On the other hand, the slower the coagulation reaction rate and the slower the diffusion rate of the coagulant, the more time there is for alignment of the latex particles, and therefore the degree of priority increases. When latex particles are not fused at all, the bonding force between the particles is only a small Van der Waals force, but when a plurality of them form a network, the holding force of the coagulated particles becomes strong. This is because as the number of latex particles in contact with each other increases, that is, the filling rate within the coagulated particles increases, the bonding of latex particles becomes more regular, and of course the number of adjacent particles increases, so the holding force increases. Moreover, it can be sufficiently handled industrially as a solid even without fusion. The required strength depends on the handling work of the coagulated particles, but as mentioned above, it depends on the physical properties of the latex particles and the filling rate of latex particles in the coagulated body, and the filling rate, expressed as solid content concentration, is generally 10 vol % or more. ,
Desirably, 20 vol% or more is required, and the larger the better. Therefore, if there are restrictions on the hardness or strength in handling the coagulated material, it is necessary to take measures such as concentrating the latex to be coagulated in advance or slowing down the coagulation reaction rate and diffusion rate. Since the coagulated particles with such an increased filling rate have a high retention strength, they can avoid deformation and destruction when subjected to physical operations such as separation and washing from the latex. The latex particles in the coagulated particles obtained in this way are regular in shape, as regular step-like layered opening planes are observed on the cut surface of the coagulated particles. This can be confirmed from the fact that it can be assumed that it is a structure of

In conventional methods, in order to handle them as particles, the holding strength must be increased and the latex particles must be fused together, so operations such as solidifying at high temperatures, heat treatment, and softening temperature are required. With highly heat-resistant resins, it is necessary to add organic solvents such as toluene and binders to promote fusion bonding, but these are completely unnecessary in the present invention.

The size and precision distribution of the coagulated particles depend on the size and distribution of each unit of coagulant dispersed in the latex, as well as the coagulation time and its dispersion. Originally,
The present invention is a method suitable for producing particles of uniform particle size without worrying about the generation of fine powder. If it is desired to form fine particles, a coagulant with low coagulation power may be dispersed and scattered in the latex in small units and separated in a short period of time. On the other hand, large particles can be created by simply doing the opposite, and the size can be controlled freely. In general, from 200 μm to 1 l of ICl ii! Suitable for obtaining particles with a large diameter. On the other hand, it is easy to obtain a uniform particle size distribution, but if you want to further improve the uniformity, it is necessary to make the sizes of the coagulant units dispersed in the latex the same and to increase the coagulation time to 1177 e. Particularly in the case of continuous operation, it is necessary to take measures to make the residence time of the coagulated particles the same in the coagulation device.

Regarding particle size, there is coalescence of coagulated particles. Since the coagulated particles produced by the present invention are regularly arranged latex particles and form a firm unit, they will not coalesce even if they come into contact in the latex when coagulated growth has stopped. There is no fear of coalescence as long as the temperature is kept below the softening and melting temperature of the latex particles. However, when the coagulated particles are growing by coagulating the surrounding latex, they tend to coalesce, especially in the initial stage of coagulation. In order to prevent the generation of coalescing particles, it is necessary to take measures such as reducing the density of coagulated and grown particles in the latex or applying kinetic energy to the coagulated particles by stirring or the like.

Extremely strong stirring may destroy the coagulated particles, impair the stability of the latex-coagulant system, and cause the entire latex to coagulate and solidify, so care must be taken. A slow laminar flow is desirable for particle growth.

In this way, the size of the coagulated particles can be freely determined from fine to lumpy, but the final size of the dried particles and sintered particles must be determined by taking into account the degree of shrinkage depending on the amount of water contained in the coagulated particles. No.

Regarding the creation of such coagulated particles, if the physical properties of the latex particles to be treated are known, the type of coagulant, properties, etc.
The range of operating factors such as stirring conditions, temperature, residence time, etc. can be selected, but to be more precise, the most desirable conditions must be determined through experiments. The important point to consider in this case is that it is important to have a clear qualitative understanding of the mechanism of coagulated particle generation mentioned above, and to know the behavior of how coagulated particles change in response to fluctuations in operating factors. In fact, it is sufficient. When carrying out the present invention, the most worrying point is that the coagulant that should be dispersed and dotted partially dissolves and diffuses into the latex, inhibiting the stability of the entire latex and eventually causing the entire latex to coagulate. It is to fall into the conventional coagulation form. Normal operations can be easily carried out by selecting the conditions such as the latex concentration, coagulant type, form, concentration, temperature, stirring, etc. as described above. However, if the process is difficult due to significant constraints in terms of quality and cost, it may be necessary to stabilize the latex or improve the equipment. For example, to stabilize latex, it is possible to coagulate by adding or adding a latex stabilizer such as a dispersant or emulsifier, and in terms of equipment, it is possible to coagulate when dispersing a coagulant. In order to suppress the dissolution and diffusion of the agent into the latex, the coagulant is dropped into an atmosphere containing atomized latex droplets to create a coagulated seed whose outer periphery is covered with coagulated material, which is then collected and dispersed in Latteparx. It is also possible to cause growth by coagulation.

Since the coagulated particles thus obtained have latex particles arranged with considerable regularity, further compaction can be easily achieved by simply removing water.

When the coagulated particles are dried at a low temperature that prevents fusion of the latex particles, the interparticle spaces from which water is removed are densely packed with particles by capillary force, forming a nearly perfect hexagonal close-packed body. This also means that it is not possible to obtain free cut planes when dividing the dried body, and it is assumed that it has a crystal structure because the open arms appear, and also that the particles produced during division This is inferred from the fact that all of the fragments have the same crystal shape, which appears to be monoclinic or hexagonal, and that the completeness of the latex particles is 73% or more. In this way, when drying at a temperature that does not allow the fusion of latex particles, even though the particles are tightly packed, the gaps between the latex particles remain continuously connected, making it extremely easy for volatile substances to collect. will be removed. This not only removes contaminants, but also facilitates the drying and removal of water present inside the particles, that is, in the spaces between the latex particles.

Also, when immersing the coagulated particles in water or an acid or alkaline aqueous solution for the purpose of removing impurities such as coagulants and emulsifiers that exist inside or on the surface of the coagulated particles, the temperature is set to a high enough temperature that the latex particles do not fuse and coalesce. As a result, water is expelled to the outside of the particles, the latex particles become more closely packed, and shrinkage of the particles is observed.

As described above, heat treatment narrows the gaps between the latex particles in the coagulated particles, resulting in a significant reduction in the water content, so it is an effective means of energy saving when energy consumption during drying is an issue.

In addition, the content of intragranular impurities can be effectively reduced by expulsion of internal water due to contraction of coagulated particles and diffusion into the aqueous phase. At the same time, water-soluble impurities and reaction/extractable substances caused by acids and alkalis can be easily removed through the gaps between the latex particles. In addition, when heat-treated in an aqueous phase at a temperature above the softening point, the particles soften and fuse from the surface layer, allowing the water inside to escape, and the surface layer becomes a continuous layer, so sufficient shrinkage no longer occurs. Moreover, voids remain within the grains even after drying. The extent of this is determined by the balance between the fusion of the surface layer and the rate of water dissipation; the higher the temperature, the faster the fusion progresses and the larger the voids become.

When the coagulated particles obtained in this way are kept below the softening temperature and dried, capillary force is generated as the water existing between the latex particles within the coagulated particles is removed.
A strong force acts to draw the latex particles together, causing the coagulated particles to contract and increase the filling rate. In the drying process, if you want to create a coarsely filled part inside the particles, you can increase the balance between the dissipation rate of intragranular water and the fusion rate between latex particles by increasing the latter. Just dry it. However, in air drying, the material temperature is kept at the wet bulb temperature in the constant rate drying range, so a high temperature that is somewhat higher than the softening/fusion temperature of the latex particles is required. However, in the case of materials with low thermal conductivity such as polymers, only the temperature of the surface layer of the particles rises, so a phenomenon is observed in which shells form on the particles as the temperature rises. This phenomenon can be avoided by drying using superheated steam. The softening temperature here means the temperature at which the substances fuse together under atmospheric pressure, and can generally be considered as the melting point of the substance. However, since there is no clear melting point for polymers, it is difficult to define them, and even the -ffI combination is determined not only by the degree of polymerization and its distribution, but also by its crystallinity and impurities that have a plasticizing effect. receive. However, in reality, if the glass transition point is Tg ('C), it can be considered to be in the range of 0.8 0.6. When implementing the present invention specifically, if the approximate value of Tg of the polymer is known, the approximate value of the softening point can be determined, so it is easy to find the optimum temperature range by trying 2 to 3 temperatures. can.

The validity of the above equation can be confirmed by examining the presence or absence of fusion of latex particles by using scanning electron up, Ifli, and mirrors on the inside of particles obtained by operating at various temperatures using polymer latexes with different softening temperatures. This is confirmed by the results of observation. When particles that have been shrunk and densified by drying or heat treatment are cut, the interior of the particles contains striped patterns that indicate traces of growth and a regular, step-like layered arrangement of crystal planes, which is more pronounced than in solidified particles. It appears clearly. Considering this together with the fold opening plane, it seems that particle contraction occurs along the crystal plane.

In the particles obtained according to the present invention, as described above, a small amount of random coarsely packed portions formed in the center of the solidified particles at the initial stage of solidification do not shrink sufficiently and remain as voids. This is the same phenomenon as in the conventional method where coagulated particles do not shrink sufficiently. Similarly, when the coagulant is solid, the microcavity at the center remains without sufficient contraction. but,
These microscopic voids in the center are extremely small compared to the entire particle, and the entire particle can be considered to be a densely packed body.

The particles obtained in this way have the following characteristics: (1) It is easy to remove volatile organic solvents including water-soluble impurities of inorganic salts and organic substances, oil-soluble impurities, and residual dirt. be. In other words, it can be recovered as highly pure particles.

Until the crystallization operation, the gaps between the latex particles in the particles are not blocked and remain continuously connected, so it is possible to use solutions such as water or acid-alkali solutions, or even alcohols, ketones, etc. It is easy to extract water-soluble impurities and oil-soluble impurities by soaking in a solvent or washing, and to remove them by washing.

In addition, in a drying operation or a stripping operation such as aeration in an aqueous phase dispersion, volatile components can be removed extremely quickly, making it easy to remove high-boiling volatile substances. In this way, the particles obtained according to the present invention can be of extremely high purity.

On the other hand, since it is necessary to increase the strength of soil particle retention when handling particles obtained by conventional methods, the latex particles are fused by heat treatment or addition of an organic refractory solvent.

As a result, the surface layer of the particle becomes a continuous polymer layer, so that in order for intragranular substances to move to the outside of the particle, they must diffuse through the continuous polymer layer, and the movement speed becomes extremely low. For this reason, it has become industrially difficult to remove contaminants from particles obtained by conventional methods. This is also the reason why emulsion polymerization is considered a drawback.

(2) It is easy to disperse and dissolve in a solvent.

In applications where once dried particles are dispersed or dissolved in an aqueous solution or an organic solvent, the dispersion speed and melting speed are high.
In addition, the dispersed particles can be finely dispersed as latex particles, which are uniform basic particles.

Normally, when dissolving a polymer in an organic solvent, a method is used in which the dissolving power of the solvent is lowered, such as by lowering the temperature, and the particles are first uniformly dispersed in the solvent, and then the particles are melted by raising the temperature.

The particles of the present invention allow the solvent to penetrate the gaps between the latex particles, and since the latex particles are not fused to each other, the latex particles can be easily dispersed into the solvent separately. As mentioned above, since it is a fused body, the dispersion unit is the particle itself, so the dispersion and dissolution operations are extremely slow. Therefore, in the conventional method, it is necessary to produce fine powder at the expense of powder properties, which causes various problems in the manufacturing process.

(3) The particles have excellent physical properties and characteristics.

Although the particles obtained by drying are not fused together at all, the latex particles are tightly packed, so they have sufficient shape retention strength and can be easily transported, stored, etc. Particles can withstand physical manipulation without collapsing. In addition, the bulk specific gravity of the particles is also larger than that of conventional products, and flow is greatly improved. Furthermore, since no fine powder is generated, handling of the granules becomes convenient. In this way, packaging costs, transportation costs can be reduced, blocking in storage tanks,
Solving bridge problems, truck lorry and bulk transportation,
In addition to making it possible to store in silos, in the case of polymers, it can be expected to have many direct and indirect benefits, such as significantly improving workability during processing and molding, significantly improving the environment due to dust, and realizing automation during processing. . Furthermore, in terms of quality, it is possible to eliminate the negative effects on quality caused by contaminants, and in polymer processing, it is possible to prevent the generation of some ungelled particles such as fluorine in molded products, resulting in homogeneous molded products and high-quality products. It is possible to stably produce quality products. Furthermore, when latex particles are used after being dispersed or dissolved in a solvent, various problems in terms of work and quality caused by partially undispersed or undissolved particles can be avoided.

In this way, many problems can be solved at once, and great benefits are expected. According to the present invention, not only can particles with no latex particles fused to each other be obtained, but also the internal structure of the particles can be freely designed according to the purpose and necessity as described below. That is, during water-phase heat treatment or drying, the degree of filling inside the particles and the predetermined morphology are adjusted by adjusting the balance between the rate of discharge of water to the outside of the particles and the rate of fusion of the latex particles.

By adjusting the degree of fusion within the outer surface of the particles by adjusting the temperature conditions during aqueous phase heat treatment and drying, for example, as the degree of fusion increases, the appearance of the particles changes from white to transparent and glossy. In other words, the particles are harder, stronger, and heavier, making them easier to handle, but the removal of contaminants,
Redispersibility into latex particles becomes difficult. Therefore, it is possible to design optimal particles by considering the degree of fusion and the form of fusion according to the purpose of use. For example, regarding the removal of impurities, various methods can be combined, such as setting the removal rate of special drying programs during aqueous phase heat treatment depending on the substance to be removed, or immersing the material in an extraction solvent after drying.

"Examples" The present invention will be explained below with reference to Examples and Comparative Examples.
The present invention is not limited in any way by these.

Example 1 A polymer latex obtained by graft polymerizing a mixture of styrene, acrylonitrile and methyl methacrylate onto a butadiene polymer, comprising 60% butadiene, 10% methyl methacrylate, 10% acrylonitrile and 20% styrene. (A) 35%
and 20% α-methylstyrene, 25% acrylonitrile
A polymer latex prepared by mixing 67% of homocopolymerized polymer latex (B) consisting of % and 55% of styrene, the solid content concentration in the latex is 30%, and the temperature is 3.
30% polymer latex at 0℃ in a 500mρ beaker
Stirring was carried out at room temperature at 400 rpm using a three-piece propeller blade with E1 m/d and d/D=0.5. Granular salt (particle size: 0.2 to 0.5 fin) was added as a coagulant and dispersed, and after about 10 seconds, the rotation speed was increased to 100 rpm, and the mixture was treated for 20 minutes with gentle stirring.

Next, coagulated particles were separated from the polymer latex through a 60-mesh sieve, washed with water, dehydrated using a Nutsche, and then dried at 60° C. for about 2 hours using a box dryer.

The obtained particles are white and have a bulk specific gravity of 0.49 (g/cJ)
A highly sharpened, highly filled, perfectly spherical powder with a particle size distribution of 6 to 16 mesh of 96% was obtained. Note that no fine coagulated particles were mixed in the separated latex. The particles were placed in dilute soapy water and left after shaking at room temperature.

After 1&40 minutes of standing, the particles were redispersed into the latex particles.

Comparative Example 1 When the same operation as in Example 1 was carried out at the initial setting of 40 rpm without lowering the rotation speed after adding the coagulant, the entire coagulation started after about 15 minutes, and after 18 minutes, Bee man was in latex inside.

Example 2 A polymer latex made by graft copolymerizing a mixture of styrene and methyl methacrylate onto a copolymer of styrene and butadiene, consisting of 35% styrene, 30% methyl methacrylate, and 35% butadiene, with a solid content concentration of 30% polymer latex at 500rr+4! Transfer 300ml to a beaker, cool externally to 5℃ with ice water, and
/ Using 3 propeller blades with D = 0.5, gently stir at 1100 rpm and add 5°C as a coagulant.
A cooled concentrated hydrochloric acid solution (approximately 35%) was added dropwise with a pipette.

After processing for about 10 minutes, the coagulated particles were dispersed from the polymer latex using a 6o mesh sieve, dehydrated using a Nutsche water wash, and then dried at 40° C. for about 4 hours using a box dryer. The obtained particles are white and have a high ffi of 0.44 (
g/cIj), the particles were perfectly spherical with almost no voids. 1g of this particle is 100m7! The mixture was placed in 20 m# of dichloromethane in an Erlenmeyer flask and stirred with a shaker at room temperature, and a homogeneous solution was obtained after 2 minutes.

Comparative Example 2 When the same operation as in Example 2 was carried out with the coagulant concentration being 1%, the latex in the beaker was all coagulated and solidified several seconds after the coagulant was added, and no particles could be formed.

Example 3 A polymer latex made by copolymerizing a mixture of acrylonitrile and vinyl chloride, consisting of 50% acrylonitrile and 50% vinyl chloride, with a solid content concentration of 25% and a temperature of 15°C was placed in a 500 m1 beaker with 300 m7' The mixture was stirred vigorously at room temperature using three propeller blades with d/D = 0.5 at 4° OrpmT, and calcium chloride powder was added and dispersed as a coagulant, and after about 10 seconds, the mixture was rotated. The number was set to 1 (lQrρm), and the treatment was carried out for 10 minutes with gentle stirring.

The coagulated particles were then separated from the polymer latex using a 60-mesh sieve, washed with water, dehydrated using a Nutsche sieve, and then dried at 45° C. for about 4 hours using a box dryer. The particles obtained were white pearls. Approximately 5 g of these particles were added to 20 ml of acetone cooled to -15° C. and shaken by hand, and a uniform dispersion state was obtained after 5 minutes.

Comparative Example 3 In Example 3, the solid content concentration of the polymer latex was changed to 3.
%, and when they were separated after 2 minutes, coagulated particles were formed, but they were soft and had extremely poor staying power, so when the polymer latex and coagulated particles were separated using a sieve, the particles were broken. Oops. However, after about 5 minutes, the entire latex solidified and became a viscous agar-like solid.

Example 4 A polymer latex copolymerized with a mixture of α-methylstyrene and acrylonitrile, consisting of 70% α-methylstyrene and 30% acrylonitrile, with a solid content concentration of 35% and a 15”C polymer latex. 500m+2
Place 300 m/d in a beaker, stir vigorously at 400 rpm using 3 scraping propeller blades with d/D=0.5, and add coagulant and 13. Te+vii +'! Add a slurry of aluminum powder dispersed in acetic acid with a pipette and disperse it into the latex, and after about 10 seconds, increase the rotation speed to 1100 r.
p, and was treated for 10 minutes with gentle stirring.

Then, the coagulated particles were separated from the polymer latex using a 60-mesh sieve, washed with water, and dehydrated using a nutsche, followed by drying at 100° C. for 3 hours in a box dryer. 17
The resulting particles were white, highly filled with 97% of 6 to 16 particles, and had a high soybean content.

Comparative Example 4 In Example 4, the initial rotation speed is IOOrpm,
When a similar operation was performed, the obtained coagulated particles were mostly coagulated in a spherical shape and had poor fluidity, and the bulk specific gravity decreased to 0.6 (g/cd). Adhesion of coagulum was observed on the feathers.

Example 5 A latex obtained by graft copolymerizing a mixture of styrene and acrylonitrile with a butadiene copolymer, comprising 30% of a polymer latex (A) consisting of 65% butadiene, 10% acrylonitrile, and 25% styrene, and α-
A polymer latex prepared by mixing 70% of a homoco-τF polymer latex (B) consisting of 70% methyl styrene, 109 methyl methacrylate, and 20% acrylonitrile, the solid content concentration of which is 30%.
, 300ml of polymer latex at a temperature of 30°C was placed in a 500m6 beaker, and after cooling to 2°C with ice water, d/
40 using 3 propeller blades of D'-0.5
Strongly stirred at 0 rpm and cooled to 0°C as a coagulant.
Add 0% calcium chloride aqueous solution and disperse, about 10%
After a few seconds, the rotation speed was set to 1100 rpm, and the treatment was carried out for 10 minutes with gentle stirring.

Then, the coagulated particles were separated from the polymer latex using a 60-mesh sieve, and an additional 500 m1! 30 in a beaker
0m! of water and put it in warm water kept at 80℃ for 60 minutes.
Medium stirring was performed for several minutes. After washing with water and dehydrating with Nutsche, it was dried at 90° C. for 3 hours in a box dryer. The filtrate was so dirty that it had a foul odor. The particle content after dehydration is 9% in hot water, from 64% before tQ to 4
It decreased to 7%. In addition, when the amounts of chloride ions and sulfate ions in the particles before and after immersion in hot water were quantified by ion chromatography, they were 7.2% to 0.4% and 1.9% to 0.1%, respectively.
% (% is calculated as dry particle weight) - The obtained dry particles were white and Takasho 1iIT 0.48 (g
The particles were perfectly spherical with a thickness of 1/2 mm.

Example 6 A copolymer latex obtained by graft polymerizing a mixture of styrene and methyl methacrylate onto polybutadiene, consisting of 40% styrene, 15% methyl methacrylate, and 45% butadiene. 300m+ latex in a 500ml beaker
! The mixture was stirred vigorously at room temperature at 4 degrees Orpm using three scraping propeller blades with d/D = 0.5, magnesium sulfate powder was added as a coagulant and dispersed, and after about 10 seconds the rotation speed was increased to 1100 rpm. The mixture was treated for 10 minutes with gentle stirring.

Then, the coagulated particles were separated from the polymer latex using a 60-mesh sieve, washed with water, dehydrated using a Nutsche, and then dried at 35° C. for 6 hours using a box dryer. The obtained particles were white, perfectly spherical particles.

Example 7 Polymer latex 33, which is a polymer latex obtained by graft copolymerizing a mixture of methyl methacrylate-1 and styrene on a butadiene polymer, which is composed of 75% butadiene, 20% methyl methacrylate, and 5% styrene. 1 part, 45% α-methylstyrene, 5% methyl methacrylate, 35% styrene and 1 part acrylonitrile.
A polymer latex prepared by mixing 67 parts of a homocopolymer polymer latex consisting of 5% with a solid content concentration of 30% at 15°C was placed in a 500 mff beaker.
00mj! Also, as a preparation, I added 50m7 of latex! 2m7 in a beaker! Then, 4 ml of a 15% chloride aqueous solution was added thereto, and the mixture was ground to a hardness using a spatula to form a finely divided solidified slurry. 5Q Om 12 The polymer latex placed in a 300 m# beaker was scraped up at room temperature and the solidified slurry was added to it while stirring at 400 rpm using 3 propeller blades of d/D''-0.5. and disperse, 1
After 0 seconds, the rotation speed was set to 1OQrpm, and the treatment was performed for 10 minutes with gentle stirring.

Then, the coagulated particles were separated from the polymer latex using a 60-menu sieve, washed with water, dehydrated, and dried at 100'C for about 1 hour using a box dryer.

When the amount of α-methylstyrene monomer in the particles of dried III& was determined by gas chromatography, it was found to be 1°8%.
It decreased significantly from 0.13% to 0.13% (% is converted to dry particle weight). The dried particles obtained were white spherical particles.

Example 8 A polymer latex prepared by graft copolymerizing a mixture of acrylonitrile, methyl methacrylate, butyl acrylate-1, and styrene onto a copolymer of styrene and butadiene, comprising 4% acrylonitrile, 40% methyl methacrylate, and 40% styrene. %, butyl acrylate 3
%, and butadiene 13% with a solid content concentration of 8% in a 500 mAm beaker.
rz! While stirring at room temperature with 3 propeller blades of d/[)-0.5 at 50 rpm,
39 ml of 0.5% 11cI aqueous solution was added. Immediately the whole thing turned into a viscous solidified slurry.

While continuing to stir, the mixture was heated to 75°C using an electric heater. After cooling it in a large amount of water, it was dehydrated using a Nutsche to collect irregularly shaped particles.

This dehydrated resin was dispersed and immersed in a large amount of 30% CaCl aqueous solution for 1 hour, and then dehydrated again using a Nutsche. The obtained resin was a water-containing resin containing CaCl, and was used as a coagulation seed.

5QQmi is a polymer latex with a solid content of 35% made by emulsion polymerization of vinyl chloride. Pour 30ml into a beaker,
While stirring with the above stirrer at 400 rpm at room temperature, the above resin was added little by little with a spatula. Stir immediately 1
The cell was lowered to 1100 rpm and left for 20 minutes. 6
When the coagulated particles were separated from the latex using a 0-mesh sieve, smooth oval spherical coagulated particles were obtained. The particles obtained by drying the coagulated particles at 50° C. in a box-type dryer were capsule-shaped composite particles having the polymer used as a coagulation seed inside and PVCI on the outside.

Example 9 A polymer latex made by copolymerizing a mixture of α-methylstyrene and acrylonitrile, consisting of 70% α-methylstyrene and 30% acrylonitrile, with a solid content concentration of 35%, was prepared in an amount of 500 ml! Hibi-
300m1! ,,! : Cooled to below 75°C with ice water. d/Dfi Three propeller blades were installed in a gas tank, and a glass tube with a narrowed tip was installed near the lower end of the propeller blade to serve as a coagulable gas supply pipe.

Once the IC1 gas (as a solidifying gas) is removed, it is -2.
Through a gas retainer cooled to 0°C, IIcI gas cooled to below -5°C was supplied through a glass tube into the latex under stirring at 60 rpm. Immediately after stopping the supply of HCI gas, the speed was lowered to 1100 rpm and the temperature was increased for 10 minutes with gentle stirring.

The coagulated particles were separated from the polymer latex using a 60 mesh sieve and dried in a box dryer for 2 hours in water at 1.05°C. The particles were highly packed true spherical particles with a chemical density of ffj of 0.52 (g/cut).

Claims (1)

[Claims] 1. (A) Adding a coagulant to an aqueous particle colloid that causes a coagulation reaction by adding a coagulant at a temperature lower than the temperature at which the colloid particles fuse together (softening temperature), and causing the coagulation to occur. (B) dissolving and diffusing the coagulant from the scattered coagulant units into the colloid; coagulating colloidal particles on the outer surface of the unit and growing the coagulated particles from the inside to the outside to form spherical particles of any size filled with colloidal particles with regularity, (C) the coagulated particles The aqueous particles are separated from the colloid to obtain coagulated particles, and (D) the colloid constituting the coagulated particles is dried while maintaining the temperature of the coagulated particles at a temperature lower than the softening temperature of the colloidal particles or heated in an aqueous phase. A method to obtain tightly packed spherical colloidal particle aggregates without particles fused together. 2. The method according to claim 1, wherein the aqueous particle colloid is a polymer latex.