KR20060055722A - A physical method to produce hollow polymer spheres - Google Patents

Abstract

The present invention relates to a method for preparing a polymer hollow sphere, comprising dissolving a polymer resin in an organic solvent to prepare a polymer solution; Forming an oil-in-water (O / W) emulsion containing a plurality of emulsified particles consisting of a polymer solution by emulsifying the polymer solution on an aqueous solution containing a surfactant; Removing the organic solvent contained in the emulsified particles to form polymer hollow spheres; And obtaining the formed polymer hollow spheres. The manufacturing method of the polymer hollow sphere according to the present invention has the advantage that not only can use various kinds of polymer resin, but also can easily prepare a polymer hollow sphere containing an active ingredient unstable against high temperature or chemical reaction.

Polymer hollow sphere, emulsion

Description

A physical method to produce hollow polymer spheres

1 is a scanning electron microscope (SEM) photograph showing a state in which a polymer hollow sphere prepared by using a polystyrene (weight average molecular weight 330,000) toluene solution having a concentration of 7% by weight is heated at 120 ° C and burst.

FIG. 2 is a SEM photograph showing a polymer hollow sphere prepared using a polystyrene (weight average molecular weight 330,000) toluene solution having a concentration of 10% by weight.

3 is a SEM photograph showing a broken state by rubbing a polymer hollow sphere prepared using a polystyrene (weight average molecular weight 330,000) toluene solution having a concentration of 30% by weight.

FIG. 4 is an SEM photograph showing open hollow spheres obtained from a poly (lactide-co-glycolide) toluene-chloroform (1: 1) solution at a concentration of 5% by weight.

FIG. 5 is an SEM image showing closed hollow spheres obtained from a poly (lactide-co-glycolide) toluene-chloroform (1: 1) solution at a concentration of 10% by weight.

The present invention relates to a method for manufacturing hollow spheres using a polymer resin, and more particularly, to a method for producing polymeric hollow spheres using only a physical method without using a chemical method.

Hollow sphere (hollow sphere) means a hollow sphere inside. These hollow spheres are used in various industrial fields, the material may be an inorganic material such as glass, or may be an organic material such as a polymer. These hollow spheres are used for a variety of purposes, mainly used for the purpose of lightening the product or carrying an effective material by using the empty space existing therein. For example, it is used for cosmetics, paints, plastics, rubber, synthetic wood, fireproof materials, pesticide carriers and the like.

Conventionally, polymer hollow spheres have been produced by various methods, the most typical of which is by chemical methods such as suspension polymerization or emulsion polymerization. In this case, the hollow spheres are prepared by dispersing the monomer in water together with the initiator and the surfactant, dissolving it, and heating and polymerizing it, which is entirely a method of producing hollow spheres by a chemical method. This chemical method is advantageous for preparing hollow spheres with uniform thickness and relatively well controlled thickness, but there is a limitation in the type of polymer that can be used as a hollow sphere material because it is possible only in the monomer which can be polymerized in suspension or emulsion state. In addition, these methods occur mainly due to radical reactions, and thus are difficult to perform in the presence of heat or chemically unstable substances. Therefore, according to this method, the material of the hollow spheres is limited, and there is a problem in that there is a limit to include heat or chemically unstable materials.

Another chemical method is a method in which a water-soluble compound and an oil-soluble compound meet each other at an interface between water and oil to form a polymer. This method also requires the use of highly reactive compounds, and the two materials have distinctly different solubility. There is a problem that the production of hollow spheres can be made only under very limited conditions such as should be.

On the other hand, as another method for manufacturing the polymer hollow spheres, there is a method using a polymer melt, there is also a problem that it is difficult to use when there is another material sensitive to heat because it must be heated to a considerably high temperature.

Therefore, the technical problem to be achieved by the present invention is to solve the limitations of the limitations of the hollow sphere material and the materials contained therein through the conventional method, as described above, for this purpose, without a chemical method The purpose of the present invention is to provide a method for producing a polymer hollow sphere that can not only use a polymer resin of a variety of materials, but also can effectively include a variety of active ingredients unstable in high temperature or chemical reaction in the hollow sphere due to the mild reaction conditions. have.

Method for producing a polymer hollow sphere for achieving the object of the present invention, (S1) dissolving a polymer resin in an organic solvent to prepare a polymer solution; (S2) forming an O / W emulsion containing a plurality of emulsion particles made of a polymer solution by adding and emulsifying the polymer solution on an aqueous solution containing a surfactant; (S3) removing the organic solvent contained in the emulsified particles to form a polymer hollow sphere; And (S4) obtaining the formed polymer hollow spheres.

At this time, the step (S3) may proceed to the process of leaving the emulsion formed in the step (S2) at room temperature. On the other hand, it may be proceeded to the process of mixing the emulsion obtained from the step (S2) to the water / alcohol mixed solvent. In addition, the step (S3) may be carried out by centrifuging the emulsion obtained from the step (S2), and mixing the organic layer obtained in the water / alcohol mixed solvent.

In addition, n-alkane is preferably added to the polymer solution prepared in the step (S1), and the concentration of the polymer solution is preferably 5 to 30% by weight.

In the present invention, the polymer resin is polystyrene, polymethylmethacrylate, polylactide, poly (lactide-co-glycolide), poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co-3 -Hydroxybalarate), poly (3-hydroxybalarate) and the like.

Hereinafter will be described in more detail to help the understanding of the present invention.

First, a polymer solution is prepared as an oil phase component capable of forming an emulsion. Here, the polymer solution is a polymer resin dissolved in an organic solvent.

The polymer resin that can be used in the present invention may be appropriately selected depending on the use of the hollow sphere to be made, and is not particularly limited as long as it can dissolve in an organic solvent and form an emulsion. In particular, in the present invention, a polymer resin is used. In other words, in the prior art, the method of synthesizing the polymer resin by a chemical method and simultaneously forming the hollow sphere was mainly used, but in the present invention, since the polymer resin is already prepared separately from the manufacturing process of the hollow sphere, the hollow sphere is The manufacturing process does not include chemical polymer synthesis.

Therefore, since the polymer resin that can be used is not limited by the polymerization method, it is possible to manufacture hollow spheres made of more various types of polymer resin.

In addition, for this reason, the polymer resin contained in the discarded product or the like can also be used, which can contribute to the recycling of the polymer material. As such a polymer resin, for example, polystyrene, polymethyl methacrylate, polylactide, poly (lactide-co-glycolide), poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co 3-hydroxy valerate), poly (3-hydroxy valerate) and the like are preferred, but are not limited thereto, and these may be used alone or in combination of two or more thereof.

The organic solvent is not particularly limited as long as it can dissolve the polymer resin uniformly, and particularly preferably a hydrophobic organic solvent. Such organic solvents include, for example, chloroform, toluene, benzene, methylene chloride, acetylacetate, and the like, which can be used alone or in combination. It is not limited.

In the present invention, the polymer solution is preferably prepared at a concentration of about 5 to 30% by weight so that the hollow spheres can be easily formed.

In addition to the polymer solution of the present invention, various active ingredients or additives may be appropriately added depending on the purpose. For example, a small amount of n-alkane, which is a liquid at room temperature, may be additionally added to the polymer solution, which may help form the polymer hollow sphere by promoting phase separation, which will be described later. Examples of such n-alkanes include hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetratecan and the like.

In addition, the polymer solution may contain a variety of active ingredients contained in the hollow sphere can expect a particular effect. For example, when preparing hollow spheres that can be used in cosmetics, oil-soluble active ingredients can be included in the hollow spheres. Such useful active ingredients include wrinkle improvement agents such as retinol, retinyl palmitate, tocopherol, tocopheryl acetate, and the like. The oil-soluble vitamins and the whitening agent, such as ascorbyl palmitate, ascorbyl palmitate, ascorbyl stearate and other useful vitamins, such as oil-soluble licorice extract, and the like, but are not limited thereto.

When the polymer solution is prepared as described above, the polymer solution is dispersed in an aqueous solution containing a surfactant to form an oil-in-water (O / W) emulsion. At this time, it is preferable that the aqueous solution containing surfactant which is an aqueous phase component uses 1 to 10 times the weight of the polymer solution used.

The surfactant concentration of the aqueous phase component used in preparing the emulsion is preferably 0.001 to 10% by weight. If the concentration of the surfactant is less than 0.001% by weight, the formation of the emulsion is not easy to achieve the original purpose is not preferable, if the concentration of the surfactant exceeds 10% by weight, the residual surfactant after the production of hollow spheres It may cause problems in the stability of the applied product due to, it is not preferable due to the disadvantage that can not express sufficient cosmetic effects such as skin safety, especially when applied to cosmetics.

At this time, there are no particular restrictions on the surfactant that can be used, for example, sorbitan trioleate, sorbitan sesquioleate, sorbitan sesquistearate, sorbitan monostearate, sorbitan monolaurate, sorbent Sorbitan fatty acid esters such as non-monopolypalmitate, glycerin monostearate, glycerin fatty acid esters such as glycerin monooleate, diglycerin dioleate, diglycerin monooleate, diglycerin monostearate, tetraglycerol monooleate, To propylene glycol fatty acids such as polyglycerol fatty acid esters such as tetraglycerol monostearate, pentaerythritol fatty acid esters such as pentaerythritol monostearate, pentaerythritol monopalmitate, propylene glycol monostearate, and propylene glycol monolaurate Polysaccharide fatty acid esters such as diethylene glycol fatty acid esters such as steer, diethylene glycol monostearate and diethylene glycol monolaurate, sucrose tristearate, sucrose palmitate, sucrose dilaurate, and the like Limonium chloride, cetrimonium bromide and the like may be used, but are not limited thereto.

As an emulsification method, a general method for preparing an O / W emulsion may be used, which is well known to those skilled in the art. In this case, a homo mixer or agitator may be used. The formed O / W emulsion contains a large number of emulsified particles. In the present invention, the emulsified particles include the aforementioned polymer solution used as an oil phase component. The size of the emulsion particles can be adjusted to the desired size by appropriately adjusting the production method and conditions of the O / W emulsion, the size of the emulsion particles is related to the size of the desired polymer hollow spheres.

When the emulsion is formed, a process of removing the organic solvent contained in the emulsion is performed, thereby forming a polymer hollow sphere. As the organic solvent mainly contained in the emulsified particles is removed, the polymer resin precipitates on the surface of the emulsified particles, and at the same time, phase separation occurs inside the emulsified particles to form hollow spheres.

As a method of removing the organic solvent used in the present invention, there is a method of removing the organic solvent by leaving the first formed emulsion in the air. In this case, in order to increase the contact with the atmosphere, it is preferable to put the emulsion in a container having a large inlet, and may also be stirred. It may also be made under vacuum conditions.

As another method, the organic solvent can be removed by mixing the formed emulsion with a water / alcohol mixture. In this case, as the organic solvent contained in the emulsified particles is dissolved in alcohol, removal of the organic solvent may be further promoted. Furthermore, it is more preferable that the emulsion is first centrifuged to separate the organic layer, and then only this organic layer is mixed with the water / alcohol mixture. At this time, methanol, ethanol, isopropanol and the like can be used as the alcohol that can be used, but is not limited thereto.

When the organic solvent contained in the emulsion is removed through this process, the viscosity of the polymer solution in the emulsion particles is increased, and in the emulsion particles, phase separation occurs between the organic solvent-rich phase and the polymer-rich phase, and finally the polymer component is formed. It can be said that the polymer resin precipitates as a solid from the rich phase to form hollow spheres.

Once the hollow spheres are formed, the hollow spheres are obtained by commonly known methods. For example, it can be based on methods, such as centrifugation, filtration, washing, and drying.

The particles of the polymer hollow sphere prepared according to the present invention can be variously controlled according to the conditions of the production method, such as the structure and content of the surfactant, the selection of the dispersing group, the drying rate after emulsification, the average particle size 10nm to 50 It is preferable to form about a micrometer.

The inside of the polymer hollow sphere may be one void cell, but may be divided into a plurality of void spaces. Further, the hollow sphere may be obtained in the form of a closed type having a smooth surface or an open type having a hole formed in the surface thereof.

As such, the hollow sphere manufacturing method according to the present invention does not include a chemical reaction process, it can only physically produce the hollow sphere. In addition, since all processes can occur at room temperature, active ingredients that are unstable at high temperatures or chemical reaction conditions can be included in the hollow spheres under milder conditions.

The present invention as described above may be implemented as the following specific embodiments, but various embodiments according to the present invention may be modified in various other forms. On the other hand, since the embodiments of the present invention are provided only for the purpose of more fully illustrating the present invention to those skilled in the art, the scope of the present invention is limited to the embodiments described below. It should be understood that it should not be interpreted as being.

Example 1 Preparation of Hollow Sphere Using Waste Polystyrene Foam through Atmosphere

After dissolving the polystyrene foam used as the packaging material for electronic products in toluene at 10% by weight, 10mL of this solution was added to 30mL of 0.02% by weight aqueous solution of cetriyltrimethylammonium bromide (CTAB) and stirred vigorously. The obtained emulsion was transferred to a flask with a wide mouth, and left in air with gentle stirring. After about 5 hours, the formed particles were centrifuged to separate the hollow spheres and dried at room temperature, yielding 80% yield.

Example 2 Preparation of Hollow Spheres Using Synthetic Polystyrene Solutions of Various Concentrations Through Atmosphere

Polystyrene having a weight average molecular weight of 330,000 was dissolved in toluene at 7, 10, 20, and 30 wt%, respectively, and 10 mL of each solution was mixed with 30 mL of 0.02 wt% CTAB aqueous solution, followed by vigorous stirring. When the size of the emulsion reached the desired level under a microscope, they were transferred to a flask with a wide mouth and allowed to stand in air with gentle stirring. After about 5 hours, the formed particles were filtered or centrifuged to separate the hollow spheres and dried at room temperature. Their yields were 70, 80, 85 and 87%, respectively, and SEM pictures of the hollow spheres obtained using 7, 10 and 30% by weight toluene solution are shown in FIGS. 1, 2 and 3, respectively.

FIG. 1 is a scanning electron microscope (SEM) photograph of a polymer hollow sphere prepared by using a 7% by weight polystyrene (weight average molecular weight 330,000) toluene solution and burst at 120 ° C. bar) represents 5 μm.

FIG. 2 is a SEM photograph showing a polymer hollow sphere prepared using a polystyrene (weight average molecular weight 330,000) toluene solution having a concentration of 10% by weight, with a scale bar showing 2 μm.

FIG. 3 is a SEM photograph showing a broken state by rubbing a polymer hollow sphere prepared using a polystyrene (weight average molecular weight 330,000) toluene solution having a concentration of 30% by weight, and a scale bar shows 2 μm.

Example 3 Preparation of Hollow Sphere Using Various Concentrations of Poly (Lactide-co-Glycolide) Through Atmosphere

A poly (lactide-co-glycolide) having a weight average molecular weight of 220,000 was dissolved in a toluene-chloroform (1: 1) solution at a concentration of 5% by weight and 10% by weight, respectively, and then 10 mL of these solutions were dissolved in a 1% by weight aqueous solution of TWEEN 20. After mixing with 30mL and stirring vigorously. When the droplet size reached a certain level, the emulsion was transferred to a wide-mouthed flask and left in air for 5 hours. The obtained spheres were recovered by centrifugation and dried at room temperature. Their yields were 80% and 90%, respectively, in which SEM images of the hollow spheres obtained in 5% and 10% by weight solutions were shown in the figures of FIGS. 4 and 5.

FIG. 4 is an SEM photograph showing an open hollow sphere obtained from a poly (lactide-co-glycolide) toluene-chloroform (1: 1) solution at a concentration of 5% by weight, with a scale bar showing 6.66 μm.

FIG. 5 is a SEM photograph showing closed hollow spheres obtained from a poly (lactide-co-glycolide) toluene-chloroform (1: 1) solution at a concentration of 10% by weight, with scale bars showing 2 μm.

Example 4 Preparation of Hollow Sphere Using Polymethacrylate

Polymethylmethacrylate having a weight average molecular weight of 250,000 was dissolved in toluene at 10% by weight, and 10 mL of this solution was vigorously stirred with 30 mL of 0.02% by weight CTAB aqueous solution. Once the droplet size reached the desired level, it was left in air for 5 hours with gentle stirring. The resulting spheres were separated by centrifugation and dried in air. The yield was 90%.

Example 5 Preparation of Polystyrene Hollow Spheres by Solvent Treatment

An emulsion was prepared by mixing 10 mL of a 20 wt% toluene solution of polystyrene having a weight average molecular weight of 350,000 with 40 mL of a 0.05 wt% CTAB aqueous solution. After stirring in air for about 1 hour, the cake of polystyrene solution droplets present in the upper layer by centrifugation was dispersed in 100 mL of a water-methanol (9: 1) solution and stirred slowly for 1 hour. The obtained hollow sphere was collected by filtration and dried at room temperature, yield of 85%.

As described above, according to the present invention, since the present invention uses a polymer resin that has already been prepared, unlike the conventional method for preparing hollow spheres by suspension polymerization or emulsion polymerization, hollow spheres of various kinds of polymer materials are more simple. The advantage is that it can be manufactured. In addition, the present invention does not include a chemical reaction process, and since the hollow sphere can be produced only by a physical process under relatively mild conditions, it is possible to produce a polymer hollow sphere including an active ingredient unstable in temperature or chemical reaction. .

Claims (7)

(S1) dissolving a polymer resin in an organic solvent to prepare a polymer solution; (S2) forming an O / W emulsion containing a plurality of emulsified particles made of a polymer solution by putting the polymer solution on an aqueous solution containing a surfactant and emulsifying it; (S3) removing the organic solvent contained in the emulsified particles to form a polymer hollow sphere; And (S4) a step of obtaining the formed polymer hollow sphere; method of producing a polymer hollow sphere, characterized in that the progress including. According to claim 1, wherein the step (S3) is a method for producing a polymer hollow sphere, characterized in that to proceed with the process of leaving the emulsion formed in the step (S2) at room temperature. The method of claim 1, wherein the step (S3) is a method for producing a polymer hollow sphere, characterized in that the process of mixing the emulsion obtained from the step (S2) with a water / alcohol mixed solvent. The method of claim 1, wherein the step (S3) is performed by centrifuging the emulsion obtained from the step (S2) and mixing the organic layer obtained by mixing the water / alcohol mixed solvent. . The method of claim 1, wherein the polymer solution of step (S1) is a method for producing a polymer hollow sphere, characterized in that prepared with a polymer solution to which n-alkanes are further added. The method according to any one of claims 1 to 5, wherein the polymer solution of step (S1) is prepared at a concentration of 5 to 30% by weight. According to any one of claims 1 to 5, wherein the polymer resin of the step (S1) is polystyrene, polymethyl methacrylate, polylactide, poly (lactide-co-glycolide), poly (3 -Hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyvallate) and poly (3-hydroxyvallate) which is a polymer resin composed of any one or two or more selected from the group consisting of Method for producing a polymeric hollow sphere characterized in that.

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