JPS59182237A - Manufacture of spherical glass article - Google Patents

Abstract

PURPOSE:To manufacture a spherical glass article, easily, by dispersing an aqueous solvent solution of a metal alkoxide containing a small amount of hydrogen fluoride in a liquid or gaseous thermal medium to accelerate the hydrolysis of the alkoxide, and forming spherical glassy gel particles. CONSTITUTION:A metal alkoxide such as Si(OCH3)4, NaOCH3, etc. is dissolved in an aqueous medium such as hydrated methanol, etc., and a small amount (about 0.1-1mol per 1 mol of the metal alkoxide) of hydrogen fluoride is added to the solution. The obtained solution is dispersed in a liquid thermal medium (e.g. liquid paraffin) which is incompatible but dispersible with the solution, of the solution is sprayed and dispersed in a gaseous thermal medium. The hydrolysis of the metal alkoxide is accelerated in the dispersed state, and spherical glassy gel particles are formed by this process. The objective spherical glass article can be obtained by heating the glassy gel at a high temperature as needed.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a method for manufacturing a spherical glass body.

More specifically, the present invention relates to a method for producing spherical glass bodies useful as column fillers for various chromatography and carriers for enzyme immobilization, and also useful as various industrial materials such as polymer filling reinforcing materials and gloss enhancers.

(b) Prior art Conventionally, as a manufacturing method for spherical glass bodies, especially micro glass spheres, the concentration of sodium silicate (usually &-〇, equivalent to about 10%)
It is known that after adjusting t IIH, it is dispersed in oil and gelled, or gelled in dry air using a spray method, but the process is complicated and takes a long time. On the other hand, it is also possible to form molten glass into a spherical shape, but this is difficult to process in practice.

(c) Purpose of the Invention The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide a complete manufacturing method by which a desired spherical glass body can be obtained in a simple process and in a short time. This is the purpose.

The inventor first focused on metal 7/L/koxide, which is known as one of the raw materials for glass and ceramic manufacturing, and added a hydrolysis catalyst such as hydrochloric acid to this solution, and then poured it into heated oil. We came up with a method to obtain a spherical glass-like gel body by adding and dispersing it, and conducted various studies and studies, but gelation did not occur and it was difficult to obtain the desired spherical glass body.

Regarding this point, as a result of further research and consideration, the present inventor found that by incorporating a small amount of hydrofluoric acid into the solution of the metal 7μ oxide, the desired spherical glass could be formed in the heated oil. Body f: We discovered the unexpected fact that it can be dispersed in a short time, and after further study, we arrived at this invention.

(→Structure of the Invention Thus, according to the present invention, an aqueous solvent solution of a metal alkoxide containing a small amount of heptathonic acid is added to and dispersed in a liquid heat medium that is incompatible with the solution but is dispersible. or by spraying and dispersing in a gaseous heat medium) to promote the hydrolysis of the metal 7μ oxide in a dispersed state to form a spherical glass-like gel body, and if necessary, the glass-like gel A method for manufacturing a spherical glass body is provided, which comprises subjecting the body to a high temperature heat treatment.

As the metal 7μ oxide in this invention, various metal alkoxides known as raw materials in the glass manufacturing field and ceramic manufacturing field can be used.
31(0CHs)a, 5j-(OCJs)4, Ti(O
C3H,)4,V(OC2Hs)s,ke (0(3H
Examples include lower alkoxy metals such as y)s, Na0CH, etc. Among these, it is usually preferable to use low a7μ koxysilanes. Note that there is no problem in using a mixture of two or more of these.As the aqueous solvent used for the aqueous solvent solution of the metal alkoxide, it is recommended to use a volatile hydrophilic solution containing water such as aqueous methanol or aqueous ethanol. Appropriate. Moreover, the concentration of the aqueous solvent solution is not particularly limited. Since the spherical diameter of the spherical glass body is usually proportional to the viscosity of the solution, the concentration of the metal alkoxide may be determined so as to obtain a viscosity corresponding to the desired spherical diameter. Note that a mineral acid such as hydrochloric acid, which is a catalyst for hydrolyzing metal alkoxide, may be added to this aqueous solvent solution.

It is necessary that the amount of hydrofluoric acid contained in the solution is small. This small amount is expressed as a ratio of 7p to 1 mo of metal alkoxide, and is 1 to 1 μμ.
is appropriate. If it exceeds 1-E-1v, gelation occurs instantaneously when dispersing in a heat medium, especially in a liquid heat medium, making it difficult to achieve sufficient dispersion, which is not preferable. Moreover, if the amount of hydrofluoric acid is too small, the time required for gelatinization is undesirably long.

This hydrogen fluoride-containing solution is dispersed in a liquid heating medium X-ray gaseous heating medium. The liquid heat medium must be a liquid that is incompatible with the above solution but can be dispersed, and specific examples thereof include liquid paraffin, hydrocarbon oil such as mineral oil, polyethylene glycol, polypropylene glycol-μ, etc. In addition to these, various liquid materials such as synthetic oils and vegetable oils can be used. Dispersion into a liquid heat medium can usually be carried out by adding all at once and stirring. At this time, the mixing volume ratio of the hydrogen heptadide-containing solution and the liquid heat medium is such that the former is higher than the latter. It is preferable to adjust the temperature as follows because spherical glass bodies can be produced with a yield of approximately 100%. In addition, the temperature of the liquid heat medium is usually 5
It is appropriate to set the temperature to about 0 to 200°C, and for example, when using an alkoxycin, the temperature is preferably about 80°C. On the other hand, a high-temperature air stream can be used as the gaseous heat medium, and dispersion in this medium is usually suitably carried out by jetting the solution.

Due to such dispersion in the heat medium, hydrolysis of the metal 7μ oxide rapidly progresses in the dispersed state, and the dispersed particles are converted into spherical glass-like gel bodies within several tens of minutes, resulting in the dispersion of the spherical glass bodies of the present invention. obtained in the state.

The spherical diameter of the formed spherical glass body is largely influenced by the viscosity of the metal alkoxide solution as described above, but it also depends on the viscosity (temperature) of the liquid heat carrier, for example (if the temperature of the liquid heat carrier is When the viscosity is low and relatively high, the sphere diameter tends to be large, and when the temperature is high and the viscosity is relatively low, the sphere diameter tends to be small. , by adjusting various conditions), it is possible to appropriately obtain particles with a large sphere diameter on the order of a cod or a particle with a micro sphere diameter on the order of μm.

The spherical glass body thus formed is a porous glass-like gel made mainly of a metal hydroxide compound, which is a hydrolyzate of a metal alkoxide, and/or a condensate thereof, and into which fluorine atoms are introduced. It consists of compounds. These spherical glasses are appropriately separated from the heat medium and put into practical use. Normally, after separation of the spherical glass formed from a liquid heat medium, it is preferable to thoroughly wash and remove the adhered liquid heat medium with various solvents or the like.

This spherical glass body is subjected to high temperature heat treatment if necessary. For example, if a whole oxide glass sphere of the same quality as conventional silica glass is intended, the spherical glass body separated above is subjected to high temperature heat treatment at 500°C or higher for a long time (for example, several hours) to achieve high condensation. All you have to do is turn it into The spherical glass bodies of the present invention made of these oxide glasses are useful as various industrial materials such as column packing materials for various chromatography, various carriers, polymer filling reinforcing materials, and gloss increasing materials.

On the other hand, the spherical glass bodies of the present invention which are not heat-treated or which have been subjected to high-temperature heat treatment at about 300°C or less do not mainly contain metal hydroxide compounds or low condensates thereof, but contain a large number of hydroxyl groups. Since the reactivity is also improved due to the introduction of fluorine atoms, it is particularly useful as a support for immobilized biocatalysts in addition to the above-mentioned uses.

Note that a super strong acid containing hydrogen fluoride may be used in place of the hydrofluoric acid used in this invention.

(E) Example Tetraethoxy 7rane 5i (OC, H4) 41 mol was mixed with 3.8 mol, 3.6 mol, and 0.28 mol of water, ethyl alcohol, and hydrochloric acid, respectively, and stirred vigorously. A solution of tetraethoxysilane in an aqueous solvent was obtained.

To this solution was added and mixed 0.1 to 1.0 μm of hydro7ric acid while stirring. This was added all at once to 5000 ml of liquid paraffin that had been preheated to about 80°C and stirred to disperse the above solution. Within about 30 minutes, the dispersed particles became gelatinous and microspherical glass bodies were obtained in a dispersed state.

The above-mentioned spherical glass body was filtered through a menglen filter to separate it from the medium, washed repeatedly with n-heptane, washed repeatedly with acetone, and then dried at 100°C. This spherical glass body has a uniform spherical shape as shown in Figure 1), and more than 95% of it has a pore diameter of about 250 to 5.
It was relatively uniform with a diameter of 00 μm.

(F) Effects of the Invention As described above, according to the present invention, spherical glass bodies useful for various purposes can be manufactured easily and in a short time, and the manufacturing cost can be reduced by 1.

[Brief Description of the Drawings] Figure 1 is an enlarged (×50 times) perspective view illustrating a spherical glass body obtained by the manufacturing method of the present invention.

Claims (1)

[Claims] (1) An aqueous solvent solution of a metal alkoxide containing a small amount of hydrofluoric acid is added to and dispersed in a liquid heating medium that is incompatible with the solution but can be dispersed, or it is sprayed into a gaseous heating medium. The method is characterized in that the hydrolysis of the metal alkoxide is promoted in a dispersed state to form a spherical glass-like gel body, and if necessary, the glass-like gel body is subjected to a high-temperature heat treatment. Method for manufacturing spherical glass bodies.