JPH07258139A - Method for producing dipentaerythritol - Google Patents

Abstract

PURPOSE:To provide an industrially and economically advantageous method for producing dipentaerythritol, capable of efficiently producing the dipentaerythritol from raw materials capable of being obtained industrially at a low cost. CONSTITUTION:Pentaerythritol is reacted with an urea compound in the presence of a zirconium catalyst, preferably an oxyhalogenated zirconium or a zirconium oxide carboxylate at 100-250 deg.C, preferably 120-220 deg.C, to provide dipentaerythritol. The zirconium catalyst is used in an amount of 0.1-100 gram atom, preferably 0.1-80 gram atom, as zirconium metal. The amounts of the raw materials used for the reaction are especially not limited, but the urea compound and the pentaerythritol are used in a ratio of 1mole/0.1-20 moles, preferably 0.5-10 moles, from the point of the production amount of the objective product and the by- production amounts of impurities. The produced dipentaerythritol is useful as a raw material for polyesters, polyethers, polyurethanes, alkyd resins, lubricating oils, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel method for producing dipentaerythritol. Dipentaerythritol is useful as a raw material for polyester, polyether, polyurethane, alkyd resin, lubricating oil and the like.

[0002]

BACKGROUND OF THE INVENTION Dipentaerythritol has been obtained by a conventional synthetic reaction of pentaerythritol, that is, by reacting formaldehyde with acetaldehyde in the presence of an alkali, and separating and purifying a by-product when pentaerythritol is produced. Is a general industrial production method (JP-A-57-139028).

Further, as a method for improving the yield of dipentaerythritol and the quality of pentaerythritol which is a main product, formaldehyde, alkali and acetaldehyde are partially charged in advance, and formaldehyde, alkali and acetaldehyde are respectively added thereto. A method has also been proposed in which the reaction is carried out by keeping the reaction at a theoretical molar ratio or higher and at a reaction temperature of 50 ° C. or lower and dropping them at the same time (Japanese Patent Publication No. 1-44689).

On the other hand, a method of synthesizing a mixture of polypentaerythritol from pentaerythritol using phosphoric acid, sulfuric acid, etc. is also known, but a means for selectively synthesizing dipentaerythritol is not described (USP-246204).
7).

[0005]

However, the above-mentioned method for producing dipentaerythritol by the reaction of acetaldehyde and formaldehyde still has the following problems. (1) Pentaerythritol and dipentaerythritol must be separated and recovered from impurities such as by-produced sodium formate, bispentaerythritol monoformal, excess formaldehyde or acetaldehyde-formaldehyde self-condensate, and the purification process is complicated. Becomes (2) The production amount of dipentaerythritol depends on the production amount of pentaerythritol.
The limit is 10 to 15%, which cannot meet the recent increase in demand.

On the other hand, according to the knowledge of the present inventors, a method of dehydrating and condensing pentaerythritol by using an acid catalyst can obtain dipentaerythritol. Erythritol is converted to high-molecular-weight polypentaerythritol, or an intramolecular condensate is produced, so that it is difficult to put it to practical use as it is.

As a solution to these problems, the present inventors have found that dipentaerythritol is produced when urea is reacted with pentaerythritol, and have previously proposed. However, although dipentaerythritol can be obtained by reacting ureas with pentaerythritol, the yield is still unsatisfactory.

[0008]

As a result of further intensive studies, the present inventors have found that the yield of dipentaerythritol can be remarkably improved when this reaction is carried out in the presence of a zirconium catalyst. It came to completion. That is, the present invention is a method for producing dipentaerythritol, which comprises reacting pentaerythritol with ureas in the presence of a zirconium catalyst. So far, a method for producing dipentaerythritol from ureas and pentaerythritol, and a method for carrying out this reaction in the presence of a zirconium catalyst have not been reported, and the present invention is a novel method for producing dipentaerythritol. . Hereinafter, the present invention will be described in more detail.

Examples of zirconium catalysts used in the method of the present invention include zirconium halides such as metal zirconium, zirconium oxide, zirconium hydroxide, zirconium fluoride, zirconium chloride, zirconium bromide and zirconium iodide, and zirconium oxychloride. Zirconium oxyhalide, zirconium sulfate, etc.
Mineral salts such as zirconium silicate, zirconium oxynitrate, zirconium oxide mineral salts such as zirconium oxyphosphate, zirconium acetate, carboxylates such as zirconium 2-ethylhexanoate, zirconium oxyacetate, zirconium oxystearate, etc. Zirconium oxide carboxylate, zirconocene dichloride, bis (pentamethylcyclopentadienyl) zirconium dichloride and other zirconocenes, zirconium ethoxide, zirconium propoxide, zirconium butoxide and other zirconium alkoxides, zirconium oxide acetylacetonate, etc. Can be illustrated.

Among these zirconium catalysts, zirconium oxyhalide, zirconium oxide carboxylate and the like are preferable. The amount of these zirconium catalysts to be used is 0.01 to 100 gram atom as zirconium metal, preferably 0.1 to 80 gram atom per 1000 mol of pentaerythritol used in the reaction.

The pentaerythritol used as a raw material in the method of the present invention can be industrially produced by reacting formaldehyde and acetaldehyde in the presence of an alkali, and used as a raw material without further purification. it can.

[0012] Examples of urea, which is the other raw material, include N-methyl urea, N-ethyl urea, N,
Substituted ureas such as N'-dimethylurea, N, N'-diethylurea, N, N'-dibenzylurea, N, N'-diphenylurea and N, N-diethylurea can be exemplified. Among these ureas, urea is preferable in consideration of economy.

The amounts of urea and pentaerythritol used in the method of the present invention are not particularly limited, but pentaerythritol is used in an amount of 0.1 to 20 mol, preferably 0.5 to 10 mol, per 1 mol of urea. If it is less than this range, the amount of dipentaerythritol produced is small and the amount of by-products of impurities increases, and if it is large, the amount of unreacted pentaerythritol recovered increases, which is economically disadvantageous.

In the present invention, ureas and pentaerythritol can be reacted in a molten state without using a solvent, but a solvent may be used if necessary. Examples of preferred solvents include dioxane, tetrahydrofuran, ethyl ether, anisole, phenyl ether, diglyme, tetraglyme, ethers such as 18-crown-6,
Esters such as methyl acetate, ethyl butyrate, methyl benzoate, γ-butyrolactone, acetone, acetophenone,
Ketones such as benzophenone, N-methylpyrrolidine-2-
On, N, N-dimethylacetamide, N-methylpiperidone, N-substituted amides such as hexamethylphosphoric triamide, N, N-diethylaniline, N-methylmorpholine,
Of tertiary amines such as pyridine and quinoline, sulfones such as sulfolane, sulfoxides such as dimethyl sulfoxide, urea derivatives such as 1,3-dimethyl-2-imidazolidinone, and phosphine oxides such as tributylphosphine oxide. Other examples include silicone oil and water.
Among these solvents, N-substituted amides, sulfones, urea derivatives, water and the like are preferable. These solvents can be used alone or as a mixed solvent.

In the method of the present invention, the reaction temperature is 100 to 250.
The reaction is carried out at ℃, preferably 120-220 ℃. The reaction temperature is
If it is less than 100 ° C, the reaction rate is extremely slow, and if it exceeds 250 ° C, the by-product of impurities increases.

The reaction pressure may be maintained at a pressure capable of maintaining a predetermined reaction temperature. Usually, it is 1 to 50 kg / cm ² . If necessary, the reaction pressure may be increased with an inert gas such as argon, helium or nitrogen. The reaction time is the reaction temperature,
Although it depends on the kind of the catalyst and the like, it is usually used for 0.05 to 100 hours, preferably 0.1 to 80 hours.

The method of the present invention can be carried out by any of a batch method, a semi-batch method and a continuous method. For example, in the case of the batch method, urea is charged with pentaerythritol, a solvent and a zirconium catalyst in a reactor, and the reaction proceeds while heating. In the case of the continuous method,
The reaction is carried out by continuously supplying urea, pentaerythritol, a solvent and a zirconium catalyst to one of the reactors and continuously withdrawing the reaction mixture from the other.

[0018]

EXAMPLES The present invention will now be described in more detail with reference to examples.

Example 1 In a glass four-necked flask having an internal volume of 500 ml equipped with a thermometer, an air-cooled tube and a stirrer, 136 g of pentaerythritol (1.
0 mol), 60 g (1.0 mol) of urea, 1.1 g (0.005 mol) of zirconium oxyacetate and 100 g of sulfolane were added as catalysts, and the mixture was heated in an oil bath and heated at 170 ° C. for 6 hours.
Ammonia gas generated during this period was purged out of the reaction system through an air cooling tube. After 6 hours, the reaction temperature was raised to 190 ° C., and the reaction was continued for 8 hours.

After the reaction, the reaction mixture was analyzed by gas chromatography to find that dipentaerythritol was 23.5 g.
(0.092 mol) was produced, and the yield based on the starting material, pentaerythritol, was 18.5%.

Example 2 A reaction was carried out in the same manner as in Example 1 except that the reaction time at 190 ° C. was changed to 16 hours. After the reaction, the reaction solution was analyzed by gas chromatography to find that 32.4 g (0.127 mol) of dipentaerythritol was produced, and the yield based on the starting material pentaerythritol was 25.5%.

Example 3 A reaction was carried out in the same manner as in Example 1 except that 0.89 g (0.005 mol) of zirconium oxychloride was used in place of zirconium oxyacetate. After the reaction, when the reaction liquid was analyzed by gas chromatography, 22.6 g (0.089 mol) of dipentaerythritol was produced, and the yield based on the starting material pentaerythritol was 17.8%.

Example 4 In Example 1, 1.53 g (0.005 mol) of zirconium oxide acetylacetonate was used instead of zirconium oxyacetate.
The reaction was performed in the same manner as in Example 1 except that l) was used. After the reaction, when the reaction liquid was analyzed by gas chromatography, 21.9 g (0.086 mol) of dipentaerythritol was produced, and the yield based on the starting material pentaerythritol was 17.
It was 2%.

Example 5 The reaction was carried out in the same manner as in Example 1 except that 0.624 g (0.005 mol) of zirconium oxide was used instead of zirconium oxyacetate. After the reaction, the reaction solution was analyzed by gas chromatography to find that 20.1 g (0.079 mol) of dipentaerythritol was produced, and the yield based on the starting material pentaerythritol was 15.8%.

Example 6 A reaction was carried out in the same manner as in Example 1 except that 1.78 g (0.005 mol) of zirconium sulfate (tetrahydrate) was used instead of zirconium oxyacetate. After the reaction, when the reaction liquid was analyzed by gas chromatography, 17.3 g (0.068 mol) of dipentaerythritol was produced, and the yield based on the starting material pentaerythritol was 13.6%.

Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that zirconium oxyacetate was not used as a catalyst. As a result, 4.9 g (0.019 mol) of dipentaerythritol was produced, and the yield based on the starting material pentaerythritol was 3.8.
%Met.

[0027]

Industrial Applicability According to the method of the present invention, dipentaerythritol can be efficiently produced from urea and pentaerythritol which are industrially available at low cost, which is extremely advantageous industrially and economically.

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Claims (1)

[Claims] 1. A process for producing dipentaerythritol, which comprises reacting pentaerythritol with ureas in the presence of a zirconium catalyst.