KR20030042409A - The Manufacturing Method Of Acryl Globular Corpuscle - Google Patents

Abstract

PURPOSE: Provided is a method for producing a spherical acrylic particle, which can control average particle size and particle size distribution of particle, and is useful for polymer additives for cosmetics. CONSTITUTION: The method for producing a spherical acrylic particle from an acrylic polymer, is characterized by comprising the steps of (i) formulating a first solution comprising acrylic polymer and a second solution comprising an emulsifier/dispersing agent; (ii) mixing the first solution and the second solution to form an emulsion from the mixture by stirring unit; and (iii) evaporating a solvent from the emulsion to precipitate spherical acrylic particles.

Description

Manufacturing Method Of Acryl Globular Corpuscle

The present invention relates to a method for producing acrylic spherical fine particles, and more particularly, to a method for producing acrylic spherical fine particles that can control the average particle diameter and particle size distribution.

The initial applications of acrylic have been used in the textile industry, starting from warp yarns, printing, sizing and other textile processing, as a basic processing agent for leather and paper, as well as the manufacturing process. Since then, it has been applied to adhesives and spread to wood, paper, and construction. Recently, it is used in electric, electronic and information fields for high-performance products, and for metals and ceramics not only for automobile and ship industry but also for aircraft, high-speed train, and environmental industry. It is applied as a substitute material for and is widely used. However, unlike acryl as a general-purpose material, import dependence in medicine, cosmetics, powder coating, and information recording, which are areas where acryl fine particles are applied, is still high.

As a conventional method of synthesizing acrylic, there is a polyacryl acid obtained by radical polymerization of acrylic acid. The resulting polymer has a very simple structure, one carboxyl group per repeat unit, converted to sodium or ammonium salts, and a chelate agent or dispersing agent or curing agent that has different properties and uses depending on the viscosity of the polymer. thickening agent). In addition, acrylic from acrylic acid ester is obtained by copolymerizing acrylic acid and polyoxyethylene acrylate. Carboxyl acid anion and steric repulsion effect can be expected.

In addition, acryl from malic anhydrous-ester system is obtained by copolymerization of maleic anhydride with polyoxyethylene acrylate. Hydrolysis of maleic anhydride produces two carboxyl groups, so high carboxyl acid density and steric repulsion effect can be expected. On the other hand, acrylic from the acrylic acid-ester crosslinking system is obtained by crosslinking polymerization of acrylic acid and bisacrylate, and shows excellent dispersibility by the steric repulsion effect of the acrylic acid anion and the crosslinked structure. Since the properties of each monomer are different in this way, it can be produced in various ways depending on the polymerization method (homopolymerization, solution polymerization, heterogeneous polymerization, suspension polymerization, emulsion polymerization).

However, in the production of acryl spherical fine particles, monolithic fine microparticles of monodispersion can be prepared when the precipitation production method or suspension polymerization by solution polymerization is applied, so that coalescence or agglomeration of the precipitated acrylic fine particles occurs as the polymerization proceeds. There is no problem. It is also impossible to control the mean particle size and particle size distribution.

Moreover, when preparing by block polymerization, the obtained block must be pulverized by a mechanical method and the process becomes complicated. In addition, in the micronization by mechanical pulverization, the obtained powder has a large particle size and it is difficult to produce independent monodisperse fine particle powders. In addition, it is also difficult to control the spherical particle shape, particle size distribution, and the like by the above method. For this reason, the development of the manufacturing method of the acrylic spherical microparticles | fine-particles excellent in monodispersity is urgently desired.

Accordingly, the present invention aims to provide a method for producing acrylic spherical fine particles that can control the average particle size, particle size distribution and the like. As a result of repeated studies in view of the problems of the prior art, the inventors have found that the above object can be achieved by a method including specific processes, and finally, the present invention has been completed.

1 is a scanning electron microscope photograph of acrylic particles prepared according to Example 1

2 is a particle size distribution diagram of the acrylic fine particles prepared in Example 1

3 is a particle size distribution diagram of acrylic fine particles prepared in Example 2

Figure 4 is a scanning electron micrograph of the acrylic particles prepared in Example 3

5 is a particle size distribution diagram of acrylic fine particles prepared in Example 3

6 is a scanning electron micrograph of the acrylic particles prepared in Example 4

7 is a particle size distribution diagram of the acrylic fine particles prepared in Example 4

8 is a scanning electron micrograph of acrylic particles prepared by Comparative Example 1

9 is a particle size distribution diagram of acrylic fine particles prepared by Comparative Example 1

The present invention includes the following steps.

In the method for producing acrylic spherical particles from acrylic polymer,

(a) a first step of preparing a first solution containing an acrylic polymer and a second solution containing an emulsion dispersant, respectively;

(b) a second step of preparing an emulsion from the mixed solution by stirring means by mixing the first solution and the second solution; and

(c) a third step of depositing acrylic spherical fine particles by evaporating the solvent from the prepared emulsion

Hereinafter, the present invention will be described in detail.

(1) First step

Acrylic polymers used are at least one of acrylic acid, methacrylic acid, acrylate ester (methyl, ethyl, n-butyl, Isobutyl, t-butyl, 2-ethyl hexyl, Desyl, 2-Ethoxy, ethyl, 2-Hydroxy propyl Acrylate) It consists of a polymer from the species.

In addition, according to the required physical properties of the acrylic spherical fine particles obtained in the present invention, the use of the final product, and the like, a polymer prepared by appropriate selection between these monomers can be used.

Using such an acrylic polymer, first, a first solution containing an acrylic polymer and a second solution containing an emulsifying dispersant are prepared as a first step. That is, in the present invention, it is necessary to prepare the acrylic polymer / organic solution and the emulsion dispersion aqueous solution as separate solutions.

(a) First solution

The solvent used for the first solution is not particularly limited as long as the acrylic polymer is substantially dissolved therein and is incompatible with the second solution. For example acetaldehyde, methyl acetate, ethyl acetate, amyl acetate, aniline, benzaldehyde, benzene, 4-chlorochloride, carbon dioxide, chloroform, formic acid, concentrated sulfuric acid, concentrated nitric acid, cyclohexane, dibutyl phthalate, ethyl acetate, Solvent containing at least one of 2-ethylene ethylene, hydrofluoric acid, 2-methylene chloride, hydrochloric acid, nitric acid, toluene, xylene, diethyl ether, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone Can be used. The ratio of acryl and solvent in the first solution may be appropriately set according to the type of acryl used, the kind of the solvent, the concentration of the second solution, and the like. Usually, acryl: solvent = 1: 3 to 30, preferably 1 : 5 to 15.

(b) second solution

The emulsion dispersant-containing aqueous solution used as the second solution is not particularly limited. For example, polymer-based three-dimensional emulsion dispersants such as gelatin, gum arabic, dextrin, casein, protein, polyvinyl alcohol, sodium alginate, albumin, and sorbitan mono Low molecular static electrostatic emulsifiers such as oleate can be used. These can use 1 type (s) or 2 or more types. Furthermore, in the present invention, a polysaccharide compound may be used in addition to the above-mentioned steric dispersant. The particle size distribution characteristic of the acrylic fine particles obtained by these can be changed.

The solvent used for the second solution is not particularly limited as long as the emulsion dispersant is substantially dissolved in addition to water and the resulting acrylic fine particles are not dissolved. Moreover, even if it is a solvent which melt | dissolves in the solvent of a 1st solution, these can also be used if it adjusts to precipitate an acryl by mixing with the poor solvent of a polymer.

The concentration of the emulsifying dispersant in the second solution may be appropriately set according to the type of acryl to be used, the concentration of the first solution, and the like. Usually, about 0.05 to 10% (w / l), preferably 0.2 to 5% (w) / l). If the concentration of the emulsion dispersant is 0.05% or less, the spherical particles are aggregated and coalesced. If the concentration of the emulsion dispersant is 10% or more, the economic efficiency is lowered, and thereafter, it is troublesome to remove the post-fixing.

(2) second process

In the second step, the first solution and the second solution are mixed to form a polymer emulsion solution from the mixed solution by the stirring means. Although the mixing ratio of a 1st solution and a 2nd solution can be suitably changed with the kind of acryl, the density | concentration of each solution, etc., Usually, it mixes so that it may be about 1: 1-20, Preferably it is 1: 2-10.

If the mixing ratio of the first solution and the second solution is 1: 1 or less, it is impossible to form the emulsified particles, and if the mixing ratio of the first solution and the second solution is 1:20 or more, the size of the reaction tank becomes large and the yield decreases.

The stirring means of the second step is capable of miniaturization of the average particle diameter by controlling the stirring speed by the homomixer by mechanical stirring by the stirrer. A homomixer can employ | adopt a well-known stirring apparatus and operation conditions as it is. The rotational speed of the stirrer may be appropriately set in accordance with the desired particle size and the like, and is usually about 1,000 to 20,000 rpm, preferably 2,000 to 10,000 rpm. If the rotational speed of the stirrer is less than 1,000rpm, the size of the emulsion particles formed is too large to obtain the desired particle size, and if the rotational speed of the stirrer is more than 20,000rpm, the economy is inferior due to overload.

Another embodiment of the stirring means of the second step is the ultrasonic stirring by the ultrasonic generator, it is possible to refine the average particle diameter by adjusting the stirring speed by the ultrasonic stirring. Ultrasonic stirring can employ | adopt a well-known stirring apparatus and operation conditions as it is. The frequency of the ultrasonic generator may be appropriately set in accordance with the desired particle size and the like, and may usually be about 20 to 130 KHz, preferably 30 to 80 KHz. Ultrasonic agitation can perform finer agitation than mechanical agitation, and other various agitation means can be used in addition to the ultrasonic agitation and mechanical stirring.

The temperature in the second step is not particularly limited and may be usually about 10 to 30 ° C, preferably 15 to 25 ° C. In addition, the stirring time may be performed until the precipitation of the acrylic fine particles is substantially completed. Usually, it is about 30 to 240 minutes, but there is no problem even if it is outside this range, but if the stirring time is 30 minutes or less, the solvent of the first solution is not completely volatilized. If the agitation time is 240 minutes or more, there is a possibility that the possibility of coagulation between particles increases.

In the second step, the present invention can further add an acrylic poor solvent to the mixed solution. Depending on the type of solvent used in the first or second solution, acrylic fine particles may not be precipitated (or difficult to precipitate). In this case, acrylic fine particles may be added to more efficiently precipitate the acrylic fine particles. Can be. The poor solvent added to the mixed solution is not particularly limited and may be appropriately selected depending on the kind of acrylic produced, the solvent used for the first solution, the second solution, and the like.

(3) Third process

In the third step, acrylic spherical fine particles are precipitated while removing the organic solvent of the first liquid from the emulsion by heating and evaporating it out of the reaction system. The heating temperature for the emulsion varies depending on the type of solvent used in the first solution, but usually 30 to 100 ° C. is preferred, and the second solution needs to be replenished in consideration of the evaporation amount of the second solution as the high temperature is heated. . If the heating temperature is 30 ° C or less, the solvent of the first solution is difficult to evaporate. If the heating temperature is 100 ° C or more, the solvent of the second solution is evaporated, and coagulation between the produced particles occurs easily.

The heating time is about 10 seconds to 30 minutes, preferably 1 to 15 minutes when the emulsion is formed. The heating for solvent evaporation may be performed until the deposition of the acrylic fine particles is completed.

The acrylic fine particles precipitated in the third step may be recovered by solid-liquid separation according to a known method such as centrifugation. When the fine particles (powder) obtained in the third step are produced as spherical particles, they are generally monodisperse with an average particle diameter of 0.05 to 80 µm (preferably 0.1 to 20 µm). According to the present invention, the irregular shape with respect to the spherical shape can be made less than 0.1% to have the maximum surface area.

Examples will be shown below to further clarify the features of the present invention. In the present invention, the average particle size and the particle size distribution were measured using a particle size analyzer (Malvern Instruments, UK), and the particle surface was observed by scanning electron microscopy (SEM).

(Example 1)

10 ml (acrylic: acetone = 1: 4) dissolved in acetone as a first solution and 20 ml of 0.5% polyvinyl alcohol-containing aqueous solution were prepared as a second solution. Both solutions were then mixed at 25 ° C. to prepare an emulsion with a homomixer (3,000 rpm). The prepared emulsion precipitated acrylic fine particles by stirring at 40 ° C for 60 minutes. Then, the precipitate was collect | recovered by the centrifugal method and the fine particle (powder) was obtained by drying under reduced pressure.

By observing the precipitated fine particles with a scanning electron microscope (SEM), it was confirmed that the acryl fine particles were composed of uniform spherical particles in the monodisperse phase. The observation result is shown in FIG. Moreover, the average particle diameter of acryl fine particles was 3.04 micrometers as a result of the measurement by the particle size analyzer. The measurement result is shown in FIG.

(Example 2)

As a first solution, 10 ml (acryl: methylene chloride = 1: 1) dissolved in methylene chloride and 20 ml of 0.5% polyvinyl alcohol-containing aqueous solution were prepared as a second solution. Both solutions were then mixed at 25 ° C. to prepare an emulsion with a homomixer (3,000 rpm). The prepared emulsion precipitated acrylic fine particles by stirring at 40 ° C for 60 minutes. Then, the precipitate was collect | recovered by the centrifugal method and the fine particle (powder) was obtained by drying under reduced pressure.

By observing the precipitated fine particles with a scanning electron microscope (SEM), it was confirmed that the acryl fine particles were composed of homogeneous spherical particles in a monodisperse phase, and the average particle diameter of the acryl fine particles by the particle size analyzer was 3.7 µm. Particle size distribution is shown in FIG. 3.

(Example 3)

As a first solution, 10 ml (acryl: acetone = 1: 4) dissolved in methylene chloride and 20 ml of a 0.5% polyvinyl alcohol-containing aqueous solution were prepared as a second solution. Both solutions were then mixed at 25 ° C. to prepare an emulsion by ultrasonic stirring (30 KHz). The prepared emulsion precipitated acrylic microparticles | fine-particles by stirring at 40 degreeC for 60 minutes. Then, the precipitate was collect | recovered by the centrifugal method and the fine particle (powder) was obtained by drying under reduced pressure.

By observing the precipitated fine particles with a scanning electron microscope (SEM), it was confirmed that the acryl fine particles were composed of uniform spherical particles in a monodisperse phase. The observation result is shown in FIG. Moreover, the average particle diameter of the acryl fine particles was 1.45 micrometers as a result of the measurement by the particle size analyzer. The measurement results are shown in FIG. 5.

(Example 4)

As a first solution, 10 ml (acryl: methylene chloride = 1: 1) dissolved in methylene chloride and 20 ml of 0.5% polyvinyl alcohol-containing aqueous solution were prepared as a second solution. Both solutions were then mixed at 25 ° C. to prepare an emulsion by ultrasonic stirring (30 KHz). The prepared emulsion precipitated acrylic fine particles by stirring at 40 ° C for 60 minutes. Then, the precipitate was collect | recovered by the centrifugal method and the fine particle (powder) was obtained by drying under reduced pressure.

By observing the precipitated fine particles with a scanning electron microscope (SEM), it was confirmed that the acryl fine particles were composed of uniform spherical particles in a monodisperse phase. The observation result is shown in FIG. Moreover, as a result of the measurement by the particle size analyzer, the average particle diameter of acryl microparticles | fine-particles was 2.33 micrometers. The measurement result is shown in FIG.

(Comparative Example 1)

It was prepared in the same manner as in Example 1 except that 10 ml (acryl: acetone = 1: 2) dissolved in acetone was used as the first solution.

By observing the precipitated fine particles with a scanning electron microscope (SEM), it was confirmed that the acrylic fine particles consisted of non-coherent particles in agglomerated phase. The observation result is shown in FIG. As a result of the particle size analyzer, the average particle diameter of acryl fine particles was 23.3 μm, and the measurement results are shown in FIG. 9.

According to the production method of the present invention, the desired particle size and its distribution form can be controlled from the micrometer to the nanometer region.

Acrylic spherical fine particles obtained by the present invention can be used as a polymer additive for cosmetics, it is possible to use a wide range of other various applications. For example, it is also useful for electrical / electronic materials, medical materials, various filter materials, optical functional materials, chromatography materials, spacer agents, film additives, composite material additives, acrylic varnish additives, and the like.

Claims (7)

In the method for producing acrylic spherical particles from acrylic polymer, (a) a first step of preparing a first solution containing an acrylic polymer and a second solution containing an emulsion dispersant, respectively; (b) a second step of preparing an emulsion from the mixed solution by stirring means by mixing the first solution and the second solution; and and (c) a third step of depositing acrylic spherical fine particles by evaporating the solvent from the prepared emulsion. According to claim 1, wherein the acrylic polymer of the first liquid of the first step is acrylic acid, methacrylic acid, acrylate ester (methyl, ethyl, n-butyl, Isobutyl, t-butyl, 2-ethyl hexyl, Desyl, 2- Ethoxy, ethyl, 2-Hydroxy propyl Acrylate) A method for producing acrylic spherical particles, characterized in that the polymer from at least one kind. The method of claim 1, wherein the solvent of the first solution is acetaldehyde, methyl acetate, ethyl acetate, amyl acetate, aniline, benzaldehyde, benzene, 4-chlorochloride, carbon dioxide, chloroform, formic acid, concentrated sulfuric acid, concentrated nitric acid, Cyclohexane, dibutyl phthalate, ethyl acetate, 2-chloroethylene, hydrofluoric acid, 2-methylene chloride, hydrochloric acid, nitric acid, toluene, xylene, diethyl ether, dimethylformamide, dimethylacetamide, N-methyl-2-pi A method for producing acryl spherical fine particles comprising at least one kind of rolidone, wherein the ratio of acryl and solvent is 1: 3 to 30. The method of claim 1, wherein the solvent of the second solution is gelatin, gum arabic, dextrin, casein, protein, polyvinyl alcohol, soda alginate, albumin and the like, high molecular stereoscopic dispersant and low molecular weight such as sorbitan monooleate A method for producing acryl spherical fine particles comprising at least one kind of an electrostatic emulsion dispersant, wherein the concentration of the dispersant in the solution is 0.05 to 10% (w / l). The method according to any one of claims 1 to 4, wherein the stirring means is mechanical stirring by a stirrer, the mixing ratio of the first solution and the second solution is 1: 1 to 20, and the rotation speed of the stirrer is A method for producing acrylic spherical fine particles, characterized in that consisting of 1,000 to 20,000 rpm, the stirring time is 30 to 240 minutes. The method according to any one of claims 1 to 4, wherein the stirring means is ultrasonic stirring by an ultrasonic generator, the mixing ratio of the first solution and the second solution is 1: 1-20, and the stirring time is 30- Acrylic spherical fine particles production method, characterized in that consisting of 240 minutes. The method for producing acrylic spherical fine particles according to claim 1, wherein in the third step, acrylic spherical fine particles are precipitated by heating and evaporating the organic solvent of the first solution at 30 to 100 ° C.