JPS6115734B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a catalyst for ketazine synthesis. The present inventors have previously discovered that silica gel is effective as a catalyst in the reaction of synthesizing ketazine from ketone, ammonia, and peroxide. (Japanese Patent Application Laid-Open No. 54-135718). Silica gel can be produced by neutralizing sodium silicate such as water glass, sodium metasilicate, or sodium orthosilicate with acid in an aqueous solution to form a gel, or by hydrolyzing silicon tetrachloride in an aqueous solution to form a gel. There are also known methods in which silicic acid esters are hydrolyzed using acid or alkali as a catalyst to form a gel, but these methods all involve silicic acid produced by neutralizing or hydrolyzing raw materials or their polycondensation. This is a method that takes advantage of the fact that substances gel through a polycondensation reaction. Furthermore, in this polycondensation reaction of silicic acid, it has been known that fluorine ions, inorganic substances such as NaC and Na ₂ SO ₄ , methylamine, trimethylamine, etc. have a promoter effect on the polycondensation reaction.

We manufactured silica gel from various silicon compounds and discovered that when these were used as catalysts for azine synthesis, the catalytic effects of silica gel differed depending on the manufacturing method. Various manufacturing methods were investigated. As a result, silica gel produced by gelling silicic acid or its polycondensate in the presence of fluorine salts or hydrogen fluoride can be produced by gelling without using these fluorides or by using other methods to promote gelation. We discovered that ketazine was more effective as a synthesis catalyst than silica gel produced by gelling it using a chemical agent.
The present invention has been completed.

The salt of fluorine in the present invention refers to an alkali metal salt of fluorine, an ammonium salt, and an acid salt thereof. Specific examples include lithium fluoride, sodium fluoride, potassium fluoride, and rubidium fluoride. , cesium fluoride, ammonium fluoride, acidic lithium fluoride, acidic sodium fluoride, acidic potassium fluoride, acidic rubidium fluoride, acidic cesium fluoride, and acidic ammonium fluoride. Sodium silicate is a sodium salt of silicic acid or its polycondensate, and is a compound with a SiO ₂ /Na ₂ O ratio, usually called the silica ratio, of 0.5 or more.
corresponds to sodium orthosilicate, and 4 corresponds to No. 4 water glass. The silicate ester is Si(OR) ₄ (R represents a saturated hydrocarbon having 1 to 4 carbon atoms) called orthosilicate ester and its oligomer.

The rate of gelation is affected by the pH of the solution, temperature, and the concentration of silicic acid in the solution, and further by the type and amount of a gelling promoter, if used. These factors interact with each other to influence the effectiveness of silica gel as a catalyst for ketazine synthesis, and after a detailed study of these factors, it was found that when the above-mentioned fluorine compound is used as a gelation promoter, It was discovered that the resulting silica gel was more effective as a catalyst for ketazine synthesis than when no gelation promoter was used or when other gelation promoters were used.

The amount of fluorine compounds used is difficult to limit simply because it is related to other factors, but if it is too small, the effect will be small, and if it is too large, it will not only limit the effect but also increase the cost of wastewater treatment etc. Because of this, there are naturally limits. Taking these into consideration, it is preferable to use F ^- in a range of 2×10 ⁻⁴ mol/ to 0.3 mol/.

The gelation temperature is from room temperature to boiling point, and the silicon concentration is
It is about 0.1 to 10% by weight as _SiO2 .

The method of the present invention will be explained in more detail below by showing typical examples. However, these are merely examples, and it goes without saying that the present invention is not limited to these.

Example 1 134.5g of sodium silicate (manufactured by Kanto Kagaku) and 38.5g of concentrated sulfuric acid were each dissolved in 0.6 parts of water, and 0.4 parts of water was dissolved.
A sodium silicate solution and a sulfuric acid solution were simultaneously added at the same speed while stirring to an aqueous solution in which 1.2 g of NH ₄ F. . The resulting gel was broken and thoroughly washed with water, the water-washed gel was loosened, dried overnight at 150°C in a dryer, and then calcined at 180°C for 3 hours under reduced pressure (1 to 2 mmHg). The obtained silica gel is crushed with a pestle.
Transfer 12g to a 50ml Erlenmeyer flask, add 27ml of Scc-butyl alcohol, and 1.133g of 90% hydrogen peroxide.
(30 mmol) and 0.005 g of EDTA.2Na are added, and ammonia gas is blown in at a flow rate of 150 ml per minute for 6 minutes while stirring, 15 ml of methyl ethyl ketone is added, and ammonia gas is further blown in at the same flow rate for 4 minutes. Next, the Erlenmeyer flask was placed in a bath at 70°C, connected to an ammonia gas blowing tube and a reflux condenser, and reacted for 6 hours while stirring and blowing ammonia gas at a flow rate of 6 ml per minute. Methyl ethyl ketone azine was extracted by gas chromatography. Quantitative analysis showed that hydrogen peroxide was produced at a yield of 80.3% of the added hydrogen peroxide. In addition, when hydrazine was quantitatively determined using potassium bromate in 2N hydrochloric acid, the amount was consistent with the amount of azine determined by gas chromatography.

Example 2 8g50 of silica gel prepared in the same manner as in Example 1 except that 10g of NH ₄ F was used instead of 1.20g of HF.
ml Erlenmeyer flask, 37 ml of isopropyl alcohol, 0.756 g (20 mmol) of 90% hydrogen peroxide,
Add 0.005 g of EDTA.2Na, and blow in ammonia gas at a flow rate of 150 ml/mm for 5 minutes while stirring at warm temperature.
After adding 2 ml of acetone, place the Erlenmeyer flask in a 60°C bath, connect the ammonia gas blowing tube and reflux condenser, and add 5 ml of ammonia gas while stirring.
React while flowing at a flow rate of ml/mm. After starting the reaction
After 30 minutes, 1, 2, 3, 4, and 5 hours, 0.25 ml of acetone was added. Analysis conducted 6 hours after the start of the reaction revealed that acetoneazine was produced in a yield of 69.3% based on the hydrogen peroxide initially added.

Example 3 The same reaction as in Example 2 was carried out using silica gel prepared in the same manner as in Example 1 except that 0.1 g of KF.HF was used instead of 1.20 g of NH ₄ F.HF. The yield was 65.0% based on the initially added hydrogen peroxide.

Example 4 140.9 g of sodium silicate (manufactured by Kanto Kagaku) and 35.3 g of concentrated sulfuric acid were each dissolved in 0.6 g of water, and both aqueous solutions were added to 1.2 g of water simultaneously at the same speed while stirring.
Stirring was continued, and after 30 minutes, 1.2 g of NH ₄ F.HF was added. After stirring, the gel was left at room temperature for 67 hours. The resulting gel was broken, thoroughly washed with water, filtered, and dried in vacuum at 180-190%. Time passed. The obtained silica gel was ground with a mortar and the same reaction as in Example 2 was carried out using this as a catalyst, and the yield of acetoneazine was 63.5% based on the hydrogen peroxide initially added.

Claims (1)

[Claims] 1. Gelation of silicic acid or its polycondensate produced by neutralization of silicate or hydrolysis of silicate ester or silicon tetrachloride in the presence of hydrogen fluoride or its salt as a gelation promoter. Characteristic method for producing silica gel catalyst for ketazine synthesis.