JPS6363696A - Saccharide-silica complex and production thereof - Google Patents

Abstract

NEW MATERIAL:A saccharide-silica complex obtained by introducing a saccharide into amorphous silica. USE:Is useful as an adsorbent, separating agent, agent for optical resolution, packaging agent for thin-layer chromatography or gel chromatography, has more improved heat stability than a saccharide itself, is water-insoluble and readily produced. PREPARATION:An alkoxysilane (e.g. tetramethoxysilane, etc.) is blended with a saccharide (e.g. glucose, etc.) and water optionally in the presence of both a solvent (e.g. isopropanol, etc.) and a reaction promoter (e.g. acetic acid) preferably at 40-80 deg.C and gelatinized. The amount of the saccharide is preferably <=1 over several mol based on 1mol alkoxysilane and that of water is preferably 2-30mol.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a sugar-silica composite and a method for producing the same;
More specifically, the present invention relates to a novel complex of sugar and silica used as a separation agent, an absorbent, a gel chromatography packing material, a catalyst, etc., and a method for producing the same.

[Prior art]

Saccharides have many hydroxyl groups and are optically active substances, so they can be used as resolving agents for optical isomers, packing agents for thin layer chromatography and column chromatography, etc. by utilizing their molecular discrimination and adsorption abilities. It is used.

However, since saccharides generally have many hydroxyl groups, they are not necessarily structurally stable and are often susceptible to heat and chemicals.

In addition, when used as a packing agent for liquid column chromatography, it is easily dissolved in water, except for special polymer substances such as cellulose, so it can be used as an adsorption/separation agent or optical resolution agent for substances in aqueous solutions. There was a drawback that it could not be used.

[Purpose of the invention]

The present invention relates to complexing saccharides and inorganic substances. After much consideration, it was discovered that when alkoxysilanes and saccharides are combined and made into a polymer, a saccharide-silica complex is produced that can exhibit unique properties that cannot be obtained from each individual alone. It is.

That is, the present invention eliminates the above-mentioned drawbacks of sugars, and
Furthermore, it is an object of the present invention to provide a composite with improved functionality and a method for producing the same.

[Structure of the invention]

The sugar-silica complex of the present invention that achieves the above object is made by incorporating sugar into amorphous silica.

Furthermore, the method for producing a sugar-silica composite of the present invention is characterized by mixing alkoxysilanes and sugars, adding water to the mixture to form a gel, and incorporating the sugars into amorphous silica. .

The sugar used in the present invention may be any water-soluble chain sugar, such as glucose (dextrose), galactose, fructose, xylose, arabinose, mannose, rhamnose, ribose, sucrose (sucrose), etc. ), lactose, maltose, agarobiose, allolactose, isomaltose, xylobiose, gentiobiose, fucose, cordibiose, chondrozin cellobiose, sophorose, turanose, trehalose, melibiose, laminaribiose, rutinose, gentianose, stachyose, cellotriose, branchose, malt Triose, fructose, lacto-N-tetraose, raffinose, agarose, amylose, amylopectin, allapan, inulin, chitin, glycogen, dextran,
Mention may be made of chondroitin and derivatives thereof.

Such wIs have many hydroxyl groups and asymmetric carbons,
Hydroxyl groups can interact with other substances, and can also coordinate with and incorporate metal ions.

In addition, asymmetric carbons cause sugar molecules to form a specific asymmetric structure,
Asymmetric structures enable the identification of geometric optical isomers of various substances.

Therefore, saccharides have molecular recognition ability and selective adsorption ability, and are expected to have catalytic ability by incorporating metal ions.

However, as mentioned above, it has many (hydroxyl groups), so
It is difficult to say that the structure is necessarily thermally and chemically stable.

On the other hand, the raw material for silica in the present invention is not particularly limited by the carbon chain length, and any alkoxysilane can be used, but lower alkoxysilanes are preferably used because of ease of drying.

Examples of flukoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

Furthermore, in the present invention, the above-mentioned alkoxysilanes and silicon halides can be used in combination, and such silicon halides include silicon fluoride, silicon chloride,
Examples include silicon bromide.

Silica obtained by gelation of such alkoxysilanes is amorphous as described below, has adsorption ability, has a large surface area, and is thermally and chemically stable, so it can be used as a separating agent, adsorbent, and It can be widely used as a catalyst.

In other words, the sugar-silica complex of the present invention has both the above molecular recognition ability and selective adsorption ability for saccharides and the adsorption separation ability of amorphous silica. Because it is incorporated into sugar, it is thermally and chemically stabilized compared to sugar itself, and is able to perform more advanced functions.

Therefore, the sugar-silica complex of the present invention is a highly functional adsorbent that exhibits strong specificity for adsorbed substances, a molecular identification gel adsorbent, a separation agent, an optical resolution agent, and a filling agent for thin layer and gel chromatography. It is useful as such.

Such a sugar-silica composite of the present invention can be produced by mixing 1fiIQ and an alkoxysilane, adding water to gel it, and drying this gel.

Generally, after drying, the dried gel is crushed to remove sugars that are simply attached to the silica and not incorporated into the silica, washed with water, and then dried again.

In order to facilitate the mixing and gelation of sugars and alkoxysilanes, a solvent is used in the present invention,
Reaction accelerators can be added.

Such solvents include -hydric and dihydric alcohols, ketones, keto alcohols, ethers, amino alcohols and acid amides, such as methanol, ethanol, propatool, and nacol, acetone, methyl ethyl ketone, diacetone alcohol. , ethyl ether, ethanolamine, propatoolamine, dimethylformamide, etc., and these can be used alone or in combination.

Any acid or base can be used as the reaction accelerator, but from the viewpoint of preventing it from remaining in the sugar-silica complex, lower carboxylic acids such as formic acid, acetic acid, and buvion are recommended. Preference is given to using acids, butyric acid, isobutyric acid, and lower amines such as methylamine, ethylamine, ammonia.

The mixing and gelling temperature of sugars and alkoxysilanes are not particularly limited, but from the viewpoint of reaction rate and thermal stability of sugars, a range of 20 to 150°C, preferably a range of 40 to 80°C is appropriate.

The mixing molar ratio of sugars and alkoxysilanes is not particularly limited either, but ¥J! Even if you use too much of Type 1, it will simply adhere to the silica and the amount that will be washed away will increase, so it should be less than the number of moles of the alkoxysilane, preferably a fraction of the mole of the alkoxysilane. It is suitable to use the following sugars:

The amount of water added for gelation is also not particularly limited, but if the amount of water is too small, the alkoxy group of the alkoxysilane will remain, and if it is too large, the sugar and silica will form a strong complex. Therefore, the amount of water added is 1 to 100 mol, preferably 2 to 30 mol, per 1 mol of alkoxysilane.

The drying temperature of the gel may be any temperature as long as it is below the decomposition temperature of sugar, and any drying method may be adopted, for example, drying at 50 to 100°C under reduced pressure using a rotary evaporator. By doing so, sugar-
A dry gel of silica complex is obtained.

The sugar-silica composite produced by this method has a structure in which sugar is incorporated into amorphous silica, which means that powder X-ray diffraction of the composite does not show any obvious diffraction peaks.
Thermal analysis shows an exothermic peak with weight loss from 250 to 480°C, and the IR spectrum of the composite shows that
This was confirmed because the IR spectrum closely resembled that of sugar itself, showing a corresponding pattern.

〔Effect of the invention〕

As described above, the sugar-silica complex of the present invention has a structure in which wIs are incorporated into amorphous silica, and 1! It has advanced and unique functions that combine the molecular discrimination and selective adsorption abilities of silica with the absorption, separation, and catalytic abilities of silica, and a synergistic effect between silica and sugar can be expected.

Furthermore, the sugar-silica complex of the present invention has superior thermal stability compared to sugar itself, and has the characteristics of being insoluble in water.

Therefore, the Tong-silica composite of the present invention is excellent as an adsorption/separation agent with high selectivity and molecular discrimination ability, a long-life and highly functional chromatography packing material, and a separation/resolution agent for geometric optical isomers.

Furthermore, the method for producing the sugar-silica composite of the present invention consists of a simple operation of mixing alkoxysilanes and sugars, adding water, and gelling, and does not require any complicated steps, so it can be easily carried out. can do.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

〔Example〕

Example 1 300n+/! Put 50.2 g of isopropanol and 6 g of acetic acid into a beaker, add 18 g of glucose and 62.7 g of tetraethoxysilane, and heat at 75°C.
The mixture was stirred for 2 hours.

Add 54.2g of water to this solution and stir at 75°C for 1 hour, then add another 50g of water and while stirring at the same temperature, the solution gradually becomes viscous and finally solidifies into a gelatinous state. A gel was obtained.

This gel was crushed to an appropriate size, placed in a 200 ml eggplant-shaped flask, and dried using a rotary evaporator at 80° C. under reduced pressure to obtain 35 g of dry gel.

This dried gel was crushed, stirred in 300 ml of water, filtered, washed, and dried to obtain a white powdery sugar-silica composite.

Yield was approximately 19g.

This composite showed no obvious diffraction peaks in powder X-ray diffraction and was found to be amorphous.

In addition, the IR spectrum corresponds extremely well to that of glucose, and thermal analysis shows that the IR spectrum corresponds extremely well to that of glucose.
It showed a large weight loss at 60°C and an exothermic peak with a peak at 315°C.

Example 2 17.1g of sucrose and 50.3g of ethanol were placed in a 200m 12 beaker, 6g of acetic acid and 62.5g of tetraethoxysilane were added thereto, and the mixture was stirred at 65-75°C for 1 hour. .

When 54.1 g of water was added to this solution and the mixture was further stirred at the same temperature for 1.5 hours, the solution solidified into gelatin.

This gel was dried in the same manner as in Example 1, and dried gel 3
5.2g was obtained.

This dried gel was stirred in 500 ml of water for 1 hour, filtered, washed with ethanol and acetone, and dried to obtain 18 g of a white powdery i-silica complex.

The obtained composite showed no obvious diffraction peaks in powder X-ray diffraction, and was found to be amorphous.

Moreover, the IR spectrum showed a pattern that corresponded very well to the IR spectrum of saccharose.

Furthermore, thermal analysis showed a large weight loss from 252 to 372°C, and an exothermic peak peaking at 324°C.

Example 3 In a 200ml beaker, add 18g of lactose and 53.5ml of lactose.
Add 3g of ethanol, add 6g of acetic acid and 64, .
1 g of tetraethodisilane was added and stirred at 70-80°C for 2 hours.

When 59 g of water was added to this solution and stirring was continued at the same temperature, the solution gradually became viscous, and after about 4 and a half hours, it gelatinized and solidified into a gelatinous state.

This was dried in the same manner as in Example 1, and 37 g of dry gel was obtained.
I got it.

500m of this dry gel! ! After stirring at room temperature for 1.5 hours, the mixture was filtered, washed with water, alcohol, and acetone, and air-dried to obtain 17 g of a sugar-silica complex.

This composite showed no obvious diffraction peaks in powder X-ray diffraction and was found to be amorphous.

The IR spectrum of the gel also showed a pattern very similar to that of lactose.

Furthermore, thermal analysis showed a large weight loss from 260 to 370°C, and an exothermic peak with a peak at 315°C.

Example 4 Put 18g of fructose and 50.8g of ethanol in a 2-00nal beaker, add 6g of acetic acid and 6g of ethanol to this.
Add 4.3g of tetraethoxysilane and heat to 65-75℃
The mixture was stirred for 2 hours and 10 minutes.

When 55.7 g of water was added to this solution and stirred at the same temperature, the solution turned into an agar-like gel after about 1 hour.

This gel was dried in the same manner as in Example 1, then washed with water and air-dried in the same manner as in Example 3 to obtain 26 g of a composite.

This composite did not show clear diffraction peaks in powder X-ray diffraction, and was found to be amorphous.

In addition, the IR spectrum of the complex showed an IR spectrum very similar to that of fructose, and thermal analysis showed 264 to 432
It showed a large weight loss as the temperature increased, and an exothermic peak peaked at 360°C.

Example 5 18.0 g of galactose and 52.8 g of ethanol were placed in a 300 ml beaker, 6 g of acetic acid and 104.5 g of tetraethoxysilane were added thereto, and the mixture was stirred at 75° C. for 2 hours.

After adding 69.1 g of water to this solution and stirring at the same temperature for 1 hour, 21.7 g of water was further added and stirring was continued.

The solution solidified after about 2 hours, and 4
9 g of dry gel was obtained.

This was carried out (processed in the same manner as Jll 3, and 40g of sugar-
A silica composite was obtained.

This composite showed no obvious peaks in powder X-ray diffraction and was found to be amorphous.

The IR spectrum showed a pattern very similar to galactose, and thermal analysis showed a large weight loss from 240 to 350°C, and an exothermic peak with a peak at 300°C.

Example 6 300II11! Put 18.0 g of maltose and 50.4 g of ethanol in a beaker, add 6 g of acetic acid and 84.1 g of tetraethoxysilane, and add 65 to 7
After stirring at 5° C. for 2 hours, 51.4 g of water was added.

After stirring at the same temperature for 1 hour, 22.4 g of water was further added, and while stirring at the same temperature, after about 2 hours, the gel solidified into agar-like form.

This was dried in the same manner as in Example 1 to obtain 42.5 g of dry gel.

Next, 33 g of sugar-silica composite was obtained by washing and air drying in the same manner as in Example 3.

This complex showed no obvious peaks in powder X-ray diffraction and was found to be amorphous.

Further, the IR spectrum showed a pattern quite similar to that of maltose, and thermal analysis showed a large weight loss at 252-354°C and an exothermic peak with a peak at 312°C.

Example 7 In a 500 ml beaker, put 15.0 g of xylose and 57.2 g of ethanol, add 4 g of acetic acid and 1
Add 66.8g of tetraethoxysilane and heat at 80℃ for 2 hours.
Stir for hours.

Next, 145.4 g of water was added to this solution, and while stirring at the same temperature for about 1 hour, an agar-like solidified gel was obtained.

This gel was dried in the same manner as in Example 1, washed with water and air-dried in the same manner as in Example 3 to form a sugar-silica complex 56.
．． 4g was obtained.

This complex shows no obvious peaks in powder X-ray diffraction;
It was found to be amorphous.

Further, the IR spectrum was very similar to that of xylose, and thermal analysis showed a large weight loss from 250 to 360°C and an exothermic peak with a peak at 318°C.

Claims (1)

[Claims] 1. A sugar-silica composite obtained by incorporating sugar into amorphous silica. 2. A method for producing a sugar-silica composite, which comprises mixing alkoxysilanes and sugars, adding water to gel the mixture, and incorporating the sugars into amorphous silica.