KR100435561B1 - Organic doped silica microsphere and process for preparing the same - Google Patents

Abstract

The present invention relates to a method for preparing an organic-containing spherical silica powder, and more particularly, to a solution of water glass solution, organic material and alkyl siloxane, and to a solution of a nonpolar solvent and a surfactant to emulsify, then gel of water glass By preparing silica powder by dropping acid or salt as an inducing agent, chemically unstable organic substances such as dyes, whitening agents and vitamins can be incorporated into chemically stable inorganic substances, thus providing functional but irritating organic substances safely to the human body. In addition, it can prevent the deterioration of organic matter by the surrounding environment as much as possible. In particular, by adding a certain amount of alkyl siloxane, it is possible to prevent the embedded organics from being easily extracted by the solvent. The present invention also relates to a method for producing an organic-containing spherical silica powder which can be widely applied to colorants, fillers, etc. in addition to cosmetic raw materials, by improving silica particles in a uniform spherical shape having a size of 1 to 10 μm.

Description

Organic doped silica microsphere and process for preparing the same

The present invention relates to a method for preparing an organic-containing spherical silica powder, and more particularly, to a solution of water glass solution, organic material and alkyl siloxane, and to a solution of a nonpolar solvent and a surfactant to emulsify, then gel of water glass By preparing silica powder by dropping acid or salt as an inducing agent, chemically unstable organic substances such as dyes, whitening agents and vitamins can be incorporated into chemically stable inorganic substances, thus providing functional but irritating organic substances safely to the human body. In addition, it can prevent the deterioration of organic matter by the surrounding environment as much as possible. In particular, by adding a certain amount of alkyl siloxane, it is possible to prevent the embedded organics from being easily extracted by the solvent. The present invention also relates to a method for producing an organic-containing spherical silica powder which can be widely applied to colorants, fillers, etc. in addition to cosmetic raw materials, by improving silica particles in a uniform spherical shape having a size of 1 to 10 μm.

In general, organic dyes or organic compounds are absorbed by the skin directly in contact with the skin to act as a toxic substance or cause allergies. In addition, natural materials, enzymes, proteins or vitamins tend to be oxidized or easily decomposed in the surrounding water or air. Accordingly, although these organic compounds or biomaterials have a number of excellent properties, their use is limited. One way to solve this problem is encapsulation or intrusion technology.

In general, the inorganic solid phase is prepared by melting or sintering at a high temperature of 1,000 ° C. or higher. However, since the sol-gel technology, which has been studied since the early 1980s, has the property of forming an inorganic solid phase even at low temperatures below room temperature, it may contain organic materials that decompose or become unstable at high temperatures. That is, organic materials such as dyes, biomaterials such as enzymes, proteins, and the like may be encapsulated or trapped in ordinary inorganic or ceramic materials. As a result, we have created organic and inorganic composite materials that combine the chemical, high temperature stability of inorganic materials and the flexibility of organic materials, or organic and inorganic hybrid materials that design and combine two materials at the molecular or atomic level. It is a field that can respond to complex, advanced, and precision. This sol-gel technology utilizes a chemical reaction in which an inorganic monomer is hydrolyzed with the aid of water, and then the sol formed is converted into a solid gel through a polycondensation reaction. Inorganic materials commonly used in sol-gel techniques include silica, alumina, titania, zirconia, and the like.

The main method used to encapsulate or embed organic materials or bio materials is organic polymers or porous inorganic materials. However, organic polymers have limitations of chemical, thermal, and bio-friendly properties, and those impregnated in the inorganic porous body are easily eluted in an environment in which the inclusions are dissolved.

On the other hand, the method of incorporating the organic material in the solution phase and gelling at the same time by the sol-gel method using an inorganic silica monomer can have several advantages as follows. Silica, which is widely used as a host of sol-gel reaction, is inorganic, so it is photochemically stable to ultraviolet rays, transparent in the ultraviolet region and visible light of 250 nm and above, and chemically stable and harmless to human body, so it can be applied to cosmetics, medicine, and other biological materials. It can be processed into various forms such as powder, film or bulk. In addition, the sol-gel reaction rate can be easily controlled as compared with other inorganic host materials. In addition, organic silane monomers in which organic matter is bonded to silicon may be bonded in an appropriate ratio to impart hydrophilicity or hydrophobicity to water. In addition, the pore size may be controlled by controlling the sol-gel reaction conditions, or the dissolution rate of the organic material entrained or encapsulated by the additive may be controlled. Accordingly, the method of incorporating or encapsulating the organic material into the sol-gel reaction has a possibility of application to various uses.

U.S. Patent 5,292,801 describes a process for incorporating enzymes, proteins or other organics into silica gel. By the way, this method uses a silicon alkoxide which can be gelled by condensation polymerization after hydrolysis with water as a starting material in producing a silica gel porous body, and the solvent used is also an organic material. Furthermore, the obtained gel body is pulverized and manufactured in the form of particles. U. S. Patent No. 5,650, 311 also describes a method of coating a sol prepared by mixing and hydrolyzing several organics with silicon alkoxide in the form of a film. However, the above methods are difficult to use expensive silicon alkoxide as starting material and to prepare in spherical particle form.

In addition, studies have been actively conducted to increase the durability or stability of the inclusion environment by incorporating organic dyes such as photochromic or laser oscillating properties, or biomolecules such as enzymes or proteins into inorganic materials, but almost all of them have a large agglomerate form. Processes for producing in film form are known. In the case of the large agglomerate form, it should be used by pulverization, in which the shape of the particles is irregular and there are many corners of the particles, and thus the physical properties are very bad to apply to cosmetics and various fillers. In addition, the above methods have organic disadvantages in the pores between the bond rings generated by the sol-gel reaction and have a large porosity due to the nature of the sol-gel process. .

Accordingly, the present inventors have tried to solve the above problems, as a result of producing a silica powder by a conventional sol-gel method, using a low-cost water glass solution as a starting material, adding an alkyl siloxane as a solvent extraction inhibitor, emulsion method By producing a, it was possible to obtain a porous silica powder in which spherical particles having a size of 1 to 10 µm and no organic matters contained therein were extracted.

Accordingly, the present invention provides a new concept that can be widely applied in the art of manufacturing silica powder in the form of sphere to reduce friction and increase filling rate, impart functionality by incorporating organic matter into inorganic material, or stabilize organic matter. It is an object of the present invention to provide a method for producing an organic-containing spherical silica powder.

1 is an electron micrograph of a red dye-containing spherical silica powder prepared according to the present invention (Example 1).

Figure 2 is a graph showing the results of comparing the UV / VIS spectra for the solution filtered by dispersing the dye-containing silica powder prepared according to the present invention by varying the alkyl siloxane content in water and then left for one day.

Figure 3 is a graph showing the results of comparative measurement of absorbance by dispersing the dye-containing silica powder in water for one day and then recovered.

The present invention provides a method for producing a silica powder containing an organic substance by sol-gel method,

To the non-polar solvent, a surfactant mixed with span 60 and tween 80 1: 2 is added, to which a water glass solution, a solution containing alkyl siloxane as stabilizer and the organic substance to be incorporated is added, followed by an emulsifier. Mixing to prepare an emulsion in the form of W / O;

Gelling while slowly adding an aqueous ammonium carbonate solution to the emulsion; And

The gelled and precipitated powder was filtered, washed with acetone, and first dried at 50-100 ° C., followed by washing with ion exchanged water and drying.

Characterized by a method for producing a spherical silica powder containing an organic material containing a.

Hereinafter, the present invention will be described in more detail for each step.

First, 2-10 weight% of surfactant which mixed Span 60 and Tween 80 in 1: 2 is added to a nonpolar solvent, More preferably, 3-5 weight% is melt | dissolved, stirring (A solution). The water glass solution is placed in a separate container, and the alkyl siloxane and the organic substance to be incorporated are added thereto and mixed well (B solution). The two solutions A and B prepared above are mixed and then emulsified with an emulsifier for about 2 minutes to form an emulsion in the form of W / O.

As an organic solvent used as an emulsion forming agent with the said water, nonpolar solvents, such as hexane and cyclohexane, can be used. Based on the content of SiO ₂ in the water glass solution, the water glass solution is used in a molar ratio of 0.01 to 0.05 with respect to the nonpolar solvent, and is used in a concentration of 1 to 5 M. If the amount of the water glass solution is out of the molar ratio range, Particle production is difficult, and even when the concentration of the water glass solution is out of the above range, the particle formation reaction is very slow, or the generated particles are agglomerated and are not preferable. The alkyl siloxane is added to improve the elution resistance to the solvent of the organic matter contained, that is, the sol-gel method serves to prevent the organic matter impregnated in the inorganic material from being dissolved by the solvent. Here, the alkyl siloxane is added in a 0.005 to 0.2 molar ratio, more preferably 0.01 to 0.1 molar ratio, based on the SiO ₂ content in the water glass solution. In this case, when too little alkyl siloxane is added, the addition effect cannot be expected, and when too much is added outside the above range, there is a problem in that aggregated particles are severely aggregated, which is not preferable. The alkyl siloxanes include 3-glycidoxypropyltrimethoxysilane (GPS), 3-aminopropyltriethoxysilane (APS), and 3- (trimethoxysilyl) propyl meta. Acrylate [3- (trimethoxysilyl) propyl methacrylate, MPS] and the like can be used. In addition, the organic material to be embedded is used in a molar ratio of 0.01 to 0.1 based on the SiO ₂ content in the water glass solution, and organic materials such as various dyes, flavorings, enzymes, and proteins may be used. If the content of the inclusions is out of the above range it is not preferable because there is a lot of parts lacking functionality or incorporated. In addition, the silica powder may further contain an inorganic material, which is intended to enhance UV protection, controlling the refractive index of the particles, and moisturizing properties. In this case, various inorganic water-soluble inorganic salts such as ZnCl ₂ , ZrOCl ₂ · 8H ₂ O, TiOCl ₂ , etc. may be used as the inorganic material, and it is preferable to use 0.01 to 0.5 molar ratio based on the SiO ₂ content in the water glass solution.

Subsequently, an aqueous solution of ammonium carbonate adjusted to 1.5 M in advance for gelation was added dropwise to the emulsion solution while stirring slowly in an amount of about 2 molar ratio with respect to the water glass solution added to the emulsion.

In the next step, the gelled and precipitated powder from the emulsion solution is filtered, washed first with acetone, and dried by hot air at about 60 to 100 ° C. for 1 hour. If the heat treatment temperature is out of the above range, the contained organic material is damaged or the safety of solvent extraction is lowered, which is not preferable. The hot-air dried powder was again dispersed in ion-exchanged water and washed secondly, followed by drying in the same manner as described above to complete the preparation of spherical silica powder containing organic matter.

Hereinafter, the present invention will be described in more detail based on the following examples, which are merely illustrative of the present invention and the present invention is not limited by the examples.

Example 1

10 g of a mixture of Tween 80 and Span 60, which are nonionic surfactants, in a weight ratio of 2 to 1 was added to 300 ml of cyclohexane, and dissolved with stirring. In a separate container, 20 g of a water glass solution of 4 M (based on SiO ₂ content) were added, to which 0.2 g of a water-soluble organic dye (lysolubin B) and 3-glycidoxypropyltrimethoxysilane (hereinafter referred to as GPS). 0.5 g (0.02 M) was added to dissolve and mixed with the solution prepared separately. The solution of the two solutions was emulsified with an emulsifier for about 3 minutes to prepare a micro emulsion. To the emulsified solution 110 g of 1.5 M ammonium carbonate solution was added slowly with stirring. After stirring for about 2 hours, the particles produced by the water glass gelling reaction were filtered, washed first with acetone, dried at 80 ° C. for 2 hours, and washed again with ion-exchanged water. The powder prepared in this manner contained an organic dye, and when observed using a scanning electron microscope, it was observed that spherical fine particles having a size of about 1 to 10 μm were produced (FIG. 1).

Example 2

10 g of a mixture of Tween80 and Span60, which are nonionic surfactants, in a weight ratio of 2 to 1 was added to 300 ml of cyclohexane, and dissolved with stirring. In a separate container, 20 g of a 4 M (based on SiO ₂ content) water glass solution was added, dissolved in 0.2 g of water-soluble nile blue dye and 1.0 g of 3-aminopropyltriethoxysilane (APS). And mixed with the solution prepared separately. The solution of the two solutions was emulsified with an emulsifier for about 3 minutes to prepare a micro emulsion. To the emulsified solution 110 g of 1.5 M ammonium carbonate solution was added slowly with stirring. After stirring for about 2 hours, the particles produced by the water glass gelling reaction were filtered, washed first with acetone, dried at 80 ° C. for 2 hours, and washed again with ion-exchanged water. The powder prepared in this way contains an organic dye, and when observed using a scanning electron microscope, it was observed that spherical fine particles having a size of about 1 to 10 μm were produced.

Comparative example

10 g of a mixture of Tween80 and Span60, which are nonionic surfactants, in a weight ratio of 2 to 1 was added to 300 ml of cyclohexane, and dissolved with stirring. 20 g of a water glass solution of 4 M (based on SiO ₂ content) was added to a separate container, and 0.5 g of a water-soluble organic dye (lysorubine B) was added thereto to dissolve and mixed with the separately prepared solution. The mixed solution was emulsified for about 3 minutes with an emulsifier to prepare a micro emulsion. To the emulsified solution 110 g of 1.5 M ammonium carbonate solution was added slowly with stirring. After stirring for about 2 hours, the particles produced by the water glass gelling reaction were filtered, washed first with acetone, dried at 80 ° C. for 2 hours, and washed again with ion-exchanged water. The powder prepared in this manner contained an organic dye, and spherical fine particles having a size of about 1 to 10 μm were produced by using a scanning electron microscope.

Test Example 1

10 g each of the organic-containing spherical silica powders prepared in Examples 1, 2 and Comparative Examples were dispersed in 200 g of ion-exchanged water, and left for 24 hours to observe the presence of dyes eluted. The results are shown in Table 1 below. It was. Also, 10 g of the powder obtained by incorporating the same dye as used in Example 1 into the commercial silica spherical powder, gelling and drying was dispersed as described above to observe the presence or absence of elution.

According to Table 1, organic dye-impregnated silica spherical powders prepared by the methods of Examples 1 and 2 were eluted, while organic dye-impregnated silica powders impregnated into the pores of the comparative examples and commercial powders were eluted. It can be seen that the elution resistance is very excellent.

In addition, the spherical silica powder prepared by the method of Example 1 was dispersed in water with 0.02 M and 0.03 M as the representative composition of the GPS content of alkyl siloxane, respectively, and left for one day, filtered, and then filtered. Comparative results of UV / VIS spectra were shown in FIG. 2. 2, it can be seen that there is no absorbance in the entire measured wavelength range, which proves that no dye is eluted from the embedded particles.

In addition, after dispersing the silica powder, Comparative Example and commercial powder prepared in the same manner as in Example 1 with GPS content of 0.02 M in water, and the solution left for one day was filtered, the absorbance with respect to the dry powder The results of comparative measurements are shown in FIG. 3. 3, it can be seen that the dye-containing spherical silica powder prepared using GPS has a characteristic absorbance by the dye-embedded dye, and thus the solvent extraction stability of the dye is very excellent.

In particular, the spherical organic matter-incorporated silica powders prepared according to the present invention (Examples 1 and 2) have a good porosity of about 700 m 2 / g and an average pore size of 7.0 nm when the porosity is investigated by nitrogen adsorption. It was confirmed that there is.

As described above, according to the method for preparing the organic-containing spherical silica powder of the present invention, since the relatively inexpensive water glass solution is used as a raw material, it is economical, and chemically stable inorganic substances that are toxic by direct contact or unstable to the surrounding environment are chemically stable. It can be incorporated into the body, which gives stability and functionality to the human body, and can obtain a completely spherical silica powder having porosity, thereby improving spreadability and filling rate. Therefore, it can be used as a cosmetic material, a colorant, a filler or a multifunctional additive such as various polymers, paper and paint. In addition, there is an effect that can be widely used in designing functional materials such as drugs, perfume carriers and biosenses by slowly releasing the embedded organic matter or increasing the reactivity.

Claims (7)

In the method for producing a silica powder impregnated with an organic substance by a sol-gel method, To the non-polar solvent, a surfactant mixed with span 60 and tween 80 1: 2 is added, to which a water glass solution, a solution containing alkyl siloxane as stabilizer and the organic substance to be incorporated is added, followed by an emulsifier. Mixing to prepare an emulsion in the form of W / O; Gelling while slowly adding an aqueous ammonium carbonate solution to the emulsion; And The gelled and precipitated powder was filtered, washed with acetone, and first dried at 50-100 ° C., followed by washing with ion exchanged water and drying. Method for producing a spherical silica powder containing the organic material, characterized in that it comprises a. The method of claim 1, wherein the nonpolar solvent is selected from hexane and cyclohexane. The method according to claim 1, wherein the concentration of the water glass solution is in the range of 1 to 5 M based on the SiO ₂ content, and is used in a molar ratio of 0.01 to 0.05 with respect to the nonpolar solvent. The method of claim 1, wherein the stabilizer alkyl siloxane is selected from 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane and 3- (trimethoxysilyl) propyl methacrylate. Manufacturing method. The method of claim 1, wherein the organic material to be incorporated is selected from dyes, flavors, enzymes and proteins. The method according to claim 1, wherein a water-soluble inorganic salt selected from ZnCl ₂ , ZrOCl ₂ · 8H ₂ O, TiOCl ₂ is further added together with the water glass solution. 7. The method according to claim 1, 4, 5 or 6, wherein the stabilizer alkyl siloxane is 0.005 to 0.2 molar ratio based on the SiO ₂ content in the water glass solution, and the organic material to be incorporated is 0.01 to 0.1 molar ratio, The inorganic salt which is further added is used at 0.01-0.5 molar ratio, The manufacturing method characterized by the above-mentioned.