KR20110081380A - Organic silica particles and method of manufacturing the same - Google Patents

Abstract

PURPOSE: An organic silica fine particle containing an organic functional group and a method for preparing the same are provided to enhance pore size. CONSTITUTION: A method for preparing organic silica fine particles by a sol-gel method comprises a step of adding alkali metal salt catalyst and hydrogenation silane precursor to the water. The alkali metal salt catalyst is denoted by chemical formula 1(MX), In chemical formula 1, M is Li, Na, K, Rb, or Cs, and X is F, Cl, Br, or I. The alkali metal salt catalyst is added in 10-30 weight parts based on 100 weight parts of hydrogenation silane precursor. The method for further comprises polymerization, isolation, washing, drying, and pulerizing.

Description

Organic silica particles and method of manufacturing the same

The present invention relates to an organosilica fine particle containing an organic functional group and a method for producing the same, and the production process is simple, economical, reproducible, environmentally friendly, and yield of organosilica fine particles in a one-step reaction compared to the conventional method. It also relates to a method for producing new organosilica fine particles that can be significantly enhanced.

In general, organosilica powder is controlled by porosity and particle size such as pore size, pore volume and specific surface area, and anti-sticking agent (anti-blocking agent) of various films used for audio, video, packaging, etc. Secondly, it is widely used as a thickener and abrasive of toothpaste, reinforcement of plastics and rubber, additives of food and medicine, and also has excellent thermal, electrical properties and chemical safety, and its application field is continuously increasing.

Conventional methods for producing fine silica particles include vapor phase decomposition method using silane tetrachloride or the like (Japanese Patent Laid-Open No. 58-410,313), sol-gel method using alkoxy silane (Japanese Patent Laid-Open No. 63-166,777), and a specific composition. There is a method of making a boric acid glass, followed by acid treatment to extract alkali (US Patent No. 2,106,744), and a method of producing by neutralization reaction of aqueous alkali silica solution with acid (US Patent No. 4,675,122). However, in the prior art, the gas phase decomposition method causes corrosion of the device due to the corrosiveness and flammability of the chlorine gas generated during gas phase synthesis, and is harmful to the human body, which makes it difficult to handle the pores. There is a problem with the limitation. In addition, in the prior art, the above-mentioned sol-gel method has high purity characteristics of the produced fine particles, pore control is possible, but since the starting material is expensive, it is difficult to industrialize due to high production cost and is not economical except in some fields. This is not the case. In addition, the method of extracting the alkali by acid treatment in the prior art is a method of melting and molding the boric acid glass of a specific composition and then heat treatment within a predetermined temperature range to perform phase separation, followed by acid treatment, washing with water and drying, Silica fine particles produced by this method have a low purity and are limited in chemical resistance, and are generally used only for special applications due to their extremely fine pore size and low pore volume.

In the above-mentioned prior art, the method of producing by neutralization reaction of aqueous alkali silica solution with acid has low raw material price, easy handling, and is widely used industrially. In addition, when manufacturing silica using this method, there are many variables such as concentration of raw materials, addition rate of raw materials and acids, reaction temperature, reaction pH, aging temperature, and time, so that porosity can be controlled by changing these conditions. In addition, in the above method, a strong acid is added to an aqueous alkaline silica solution to lower the pH to 1.5 to produce a silica sol under a strong acid atmosphere, and then gelled to pulverize and separate particles according to the intended use to prepare silica fine particles. However, the porous silica fine particles produced by this method have a compact structure and have a small pore size (for example, 20 to 40 mm 3), a small pore volume (for example, 0.25 to 0.4 mL / g), and a specific surface area. It can be used only for some applications such as desiccant, about 500 ~ 800 ㎡ / g.

In order to solve the problems of the prior art, the synthesized silica gel is washed with an alkaline solution for a long time (for example, 10 hours or more) to increase the pore size and make the pore volume 1.2 mL / g or more (Japanese Patent Laid-Open No. 2). -289,670). However, this method requires a lot of washing time, a process takes more than two to three days, the equipment is large in mass production, resulting in a large cost and area of the equipment, high manufacturing costs.

In addition, a method of shortening the manufacturing process by gelling in an alkaline atmosphere has been proposed, but it is difficult to control the reaction due to the rapid reaction of acid and alkali when inputting raw materials, so that it is difficult to obtain homogeneous silica fine particles, and the uniformity of each product of the lot is inferior. That is, the silica fine particles produced by the prior art as described above have a limited pore volume and thus have limitations in use. In order to increase the pore volume, the silica fine particles need to be washed for a long time and a manufacturing cost increases.

The present invention is to solve the problems of the prior art as described above, the present invention uses a very stable hydrogenated silane as a precursor as a silica source (silica source), using a cheap alkali metal salt as a catalyst It is economical, environmentally friendly, and can improve the homogeneity of organosilica fine particles under the condition that rapid reaction occurs when mixing the alkali silica aqueous solution and the acid solution, and has a simpler process for producing organosilica fine particles. The purpose is to provide.

More specifically, the present invention can simultaneously proceed with hydrolysis and polymerization by using an alkali metal salt as a catalyst, economical cost savings, can prevent the cause of secondary pollution due to harmful chemicals, environmentally friendly, hydrogenated silane It is an object of the present invention to provide a method for producing organosilica fine particles having high yield and high purity in one step by using a sol-gel method.

The present invention has been made to achieve the above object, and is simple, economical, and reproducible as well as environmentally friendly, and significantly improves the yield of organosilica fine particles compared to organic silica fine particles containing organic functional groups and conventional methods. It provides a method for producing new organosilica fine particles that can be.

At this time, if there is no other definition in the technical terms used in the present invention, it has a meaning commonly understood by those skilled in the art to which the present invention belongs, and in the following description unnecessarily obscure the subject matter of the present invention. Description of known functions and configurations that may be omitted.

The present invention relates to an organosilica fine particle containing an organic functional group and a method for producing the same, the fine particle having an organic functional group can be usefully used in various fields such as rubber, ceramics, sensors, drug delivery materials, paint, etc. Efforts have been made to produce such organic functional group-containing microparticles. As a representative example, a method of modifying the surface of the microparticles using toxic acids, base catalysts or expensive platinum, palladium catalysts has been generally performed to introduce desired organic functional groups onto the microparticles surface. However, according to the above method, it is difficult not only to introduce the functional groups homogeneously into and out of the fine particles, but also difficult to remove the catalyst and change the intrinsic properties of the fine particles due to the introduction of new materials.

Accordingly, the present invention provides a method for preparing organosilica fine particles by the sol-gel method, which comprises hydrolyzing and polymerizing by adding an inexpensive, non-toxic alkali metal salt catalyst and structurally stable hydrogenated silane precursor to water. It provides a method for producing environmentally friendly organosilica fine particles.

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

The present invention relates to an organosilica fine particle containing an organic functional group and a method for producing the same, and to a method for producing organosilica fine particles by a sol-gel method, wherein the alkali metal salt catalyst is represented by the following Chemical Formula 1 in water and It provides a method for producing an environmentally friendly organosilica microparticles comprising the step of hydrolysis and polymerization by adding the hydrogenated silane precursor.

[Formula 1]

MX

[In Formula 1,

M is Li, Na, K, Rb or Cs and X is F, Cl, Br or I.]

[Formula 2]

R-SiH ₃

[In Formula 2, R is C1 to C10 alkyl or C3 to C10 aryl.]

More specifically, the present invention performs hydrolysis of the hydrogenated silane precursor by adding an alkali metal salt catalyst to water, and the polymerization reaction of the hydrolyzate proceeds without addition of another basic catalyst to the aqueous solution containing the hydrolyzate. That is, hydrolysis and polymerization can proceed simultaneously with one alkali metal salt catalyst. In addition, when the alkali metal salt catalyst is used, it enhances the effect of salt on hydrothermal stability. When organosilica is synthesized by platinum catalyst and other catalysts, non-uniform organosilica including all structures of T ¹ , T ² , and T ³ is formed. However, when the alkali metal salt is used, most of the T ³ structure has a great advantage of obtaining a relatively uniform organosilica. In addition, when the alkali metal salt catalyst is added to the hydrothermal reaction mixture, the structure does not change much even after treatment for 12 hours in boiling water, and the hydrothermal stability of the organosilica fine particles, which is the final product, is greatly increased.

The present invention is a novel synthesis method that is easy to add salt effect and metal addition in one step reaction during hydrothermal reaction because it is in equilibrium. In addition, the organosilica fine particles according to the present invention can be used as a wear control additive during tire manufacture due to an increase in hydrothermal stability.

In the present invention, the alkali metal salt catalyst is preferably added in an amount of 10 to 30 parts by weight, more preferably 10 to 20 parts by weight, based on 100 parts by weight of the hydrogenated silane precursor. When the addition amount of the alkali metal salt catalyst is added in the above range, the silica particles can be uniformly obtained, and when the addition amount of the catalyst is less than 10 parts by weight, organosilica particles having a structure of silsesquioxane are obtained. And only siloxane polymers that are oligomers are produced.

In addition, the water used in the present invention may be preferably used in distilled water, it is preferably used in a weight ratio of 1: 2 to 3 compared to the hydrogenated silane precursor.

In addition, the method according to the present invention provides a superelectric material of silsesquioxane (k <2.2) corresponding to the position of RSi (OSi) _x (OH) _3-x tetrahedron. Silsesquioxane is a substance having three functional groups and one substituent (R), wherein R is hydrogen, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkylene, substituted or unsubstituted C4 to C10 allyl or substituted or unsubstituted C4 to C10 allylene. Silsesquioxanes have a variety of structures, including random, ladder, cage, and partial cages.

Among them, the present invention may provide a silsesquioxane having a cage structure, and the silsesquioxane having a cage structure forms a net structure in which organic-inorganic mixtures are formed, and an inorganic frame network having a siloxane bond is formed therein. It consists of a reactive or non-reactive organic compound on the outside. The silsesquioxanes thus have a net structure which, due to their interconnection, has much higher mechanical stiffness and strength compared to metal oxides containing only terminal organic groups.

Accordingly, the present invention can provide a method for producing organic silica fine particles containing organic groups for interconnection of metal atoms such as Si more simply and environmentally friendly.

Looking at the prior art, the use of a template for the polymerization reaction in the preparation of the organosilica fine particles or involves a high heat treatment of 400 ℃ or more. However, no template is needed in the present invention and no high heat treatment is required.

In the present invention, the temperature required for the polymerization reaction is preferably 30 to 70 ° C, more preferably 40 to 60 ° C. The present invention has a polymerization reaction at a relatively low temperature compared to the prior art, in the case of the temperature range has the advantage of obtaining a structure of silsesquioxane of a stable structure, when the temperature is less than 30 ℃ silsesqui Silica of the oxane structure is not formed, and only siloxane which is an oligomer is produced.

In the present invention, the reaction time for hydrolysis and polymerization is preferably about 5 to 50 hours.

In addition, the method for preparing organosilica fine particles of the present invention further includes the step of separating, washing, drying and pulverizing after the polymerization. The washing is preferably repeated washing several times with one or two or more mixed solvents selected from distilled water, diethyl ether, alcohol, acetone, drying is 30 ~ 70 ℃, more preferably a temperature of 40 ~ 60 ℃ It is preferred to be made from. In addition, the grinding may use a conventional method used in the art.

Organosilica fine particles produced by the production method according to the invention has a pore size of 20 ~ 500 mm 3, pore volume 0.3 ~ 0.6 mL / g, specific surface area 600 ~ 1200 m ² / g.

The present invention is a method for producing organosilica fine particles by the sol-gel method, using a structurally very stable hydrogenated silane precursor as a silica source, instead of the usual alkoxy silane, and is a cheap and environmentally friendly catalyst. The organosilica microparticles having increased pore size and pore volume can be prepared through hydrolysis and polymerization using an alkali metal salt catalyst.

In addition, the present invention provides a method for producing new organosilica fine particles, which is simple, economical, and reproducible as well as environmentally friendly, and can significantly improve the yield of organosilica fine particles with a one-step reaction compared to the existing method. By doing so, organic silica fine particles having high yield and high purity can be produced.

1 is a graph showing the analysis results of the infrared spectroscopy of the organosilica fine particles obtained in Example 1 of the present invention, Figure 2 (a) and (b) of the organosilica fine particles obtained in Example 1 of the present invention Electron micrographs (x15,000 and x50,000, respectively) are shown.
3 is a graph showing the ²⁹ Si Solid NMR analysis results of the organosilica fine particles obtained in Example 1 of the present invention, Figure 4 is an X-ray diffractometer analysis of the organosilica fine particles obtained in Example 1 of the present invention 5 is a graph showing a thermal analysis result of the organosilica fine particles obtained in Example 1 of the present invention.

Hereinafter, the present invention may be better understood by the following examples, which are intended to illustrate the present invention and are not intended to limit the protection scope of the present invention.

[Test Example]

1) nuclear magnetic resonance (NMR; Nuclear magnetic structure analysis by resonance )

All solid state NMR experiments were performed with a Bruker DSX 400 NMR spectrometer. ^{The 29} Si MAS-NMR spectra were recorded at a spin rate of 5 kHz and a pulse delay of 5 seconds.

2) Structural Analysis by Fourier Transform Infrared Spectrometry (FT-IR)

The FT-IR experiments were made from Perkin Elmer Spectrum GX KBr pellets and used to characterize the vibratory adsorption spectra of si-O-si structures at 1150 cm ⁻¹ .

3) Structural analysis by thermogravimetric analysis (TGA)

Using TGA-50A (Shimadzu, Japan) was measured to 1000 ℃ at a rate of 10 ℃ / min in N ₂ atmosphere.

4) Structure analysis by PXRD (Powder X-ray diffractometer)

In order to confirm the crystallinity of the organosilica prepared in the following examples, the diffraction pattern of the PXRD pattern was measured by D / MAX Ultima III X-ray (λ = 0.1542 nm) of Rigaku Corporation.

5) Structural analysis by scanning electron microscope (SEM)

The particle size and shape of the powder were observed using JSM-7500F.

Example 1

2.5 g (46.3 mmol) of distilled water was added to a 100 mL round bottom flask, and 0.135 g (2.3 mmol) of LiCl was added to dissolve it, and then 1 g (46.3 mmol) of monomer phenylsilane was slowly added dropwise thereto. The resulting mixture was stirred at 50 ° C. for 24 hours and then separated, washed and dried.

The washing step was washed twice with distilled water and three times with diethylether to remove the remaining salt and silane. In addition, the drying step was dried for 24 hours in a vacuum oven at 50 ℃, and finely ground to agate induction to produce organosilica fine particles.

FIG. 1 is a graph showing an analysis result of an infrared spectrometer of organosilica fine particles obtained in Example 1, and the absorption band exhibited by asymmetric stretching of Si-O-Si through FIG. 1 exhibits high intensity at 1150 cm ⁻¹ . It was confirmed that the Si-H is converted to Si-O-Si. 2 (a) and 2 (b) show electron micrographs (x15,000 and x50,000, respectively) of the organosilica microparticles obtained in Example 1, and the outer surface of the organosilica microparticles is soft in the form of particles. Organosilica fine particles of relatively uniform size were identified. FIG. 3 is a graph showing the results of ²⁹ Si Solid NMR analysis of the organosilica microparticles obtained in Example 1, and of the polysilsesquioxane structure at -50 ppm and -80 ppm through FIG. The structures of the same T ¹ , T ³ (the structures of polysilsesquioxane include D-position, T-position, and Q-position, which are determined by the position indicated by chemical shift in ²⁹ Si Solid NMR. According to the organic silica particles, the chemical shift was shown at-50 ppm and-80 ppm, respectively, indicating the positions of T ¹ and T ³ ).

4 is a graph showing an analysis result of the X-ray diffractometer of the organosilica fine particles obtained in Example 1 of the present invention, the structure of the particle shows the pattern of the typical silsesquioxane at the position of the peak appearing in the 2θ value It was. Figure 5 is a graph showing the thermal analysis results of the organosilica microparticles obtained in Example 1, it was confirmed that the weight loss occurred about 40% to 1000 ℃ through FIG.

The organosilica microparticles prepared in Example 1 have a pore size of 200 mm ³ , a pore volume of 0.5 mL / g, and a specific surface area of 900 m ² / g.

Comparative Example 1

2.5 g (46.3 mmol) of distilled water was added to a 100 mL round bottom flask, and 1 g (46.3 mmol) of monomer phenylsilane was slowly added dropwise thereto, followed by the same procedure as in Example 1.

In Comparative Example 1, only siloxane was formed, but organosilica was not produced.

Claims (7)

In the method for producing organosilica fine particles by the sol-gel method,
A method for producing organosilica fine particles comprising adding an alkali metal salt catalyst and a hydrogenated silane precursor to water to hydrolyze and polymerize. The method of claim 1,
The alkali metal salt catalyst is a method for producing organosilica fine particles, characterized in that the following formula (1).
[Formula 1]
MX
[In the above formula (1)
M is Li, Na, K, Rb or Cs and X is F, Cl, Br or I.] The method of claim 2,
The hydrogenated silane precursor is a method for producing organosilica fine particles, characterized in that the following formula (2).
(2)
R-SiH ₃
[In Formula 2, R is C1 to C10 alkyl or C3 to C10 aryl.] The method of claim 1,
The alkali metal salt catalyst is 10 to 30 parts by weight based on 100 parts by weight of the hydrogenated silane precursor method for producing organosilica fine particles. The method of claim 1,
The polymerization method of producing organosilica fine particles made at a low temperature of 30 ~ 70 ℃. The method of claim 1,
Separating, washing, drying and pulverizing after the polymerization method of producing organosilica fine particles. Organosilica microparticles prepared by the method of any one of claims 1 to 6.

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