JPH05194458A - Method for purifying glycidol - Google Patents

Abstract

PURPOSE:To obtain the subject method for purifying glycidol in good yield in which the polymerization loss of the glycidol is suppressed in a purifying process. CONSTITUTION:Allyl alcohol is made to react with peracetic acid to provide a crude reactional solution containing glycidol. An ester compound having a higher boiling point than that of the glycidol as a diluent is added to the resultant crude reactional solution. In a state of the substantially reduced concentration of the glycidol in respective trays of a distillation column, the crude reactional solution is distilled.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for purifying glycidyl. Glycidole is a substance useful as a raw material of intermediates for glycidyl ether, glycidyl ester, glycerin ether, glycerin ester, aminopropanediol, etc., for pharmaceutical and agricultural chemicals, paints, and UV curing agents for semiconductors.

[0002]

2. Description of the Related Art A method for producing glycidyl by reacting allyl alcohol with peracetic acid is known. Glycid
In general, the reaction crude liquid is charged into a distillation column, and unreacted allyl alcohol, ethyl acetate (water in some cases) as a solvent for peracetic acid, and low boiling substances such as acetic acid as a by-product are distilled. Then, the product is commercialized by further distillation to remove high-boiling components such as glyceryl glycidyl ether, glycerin allyl ether and stabilizer of peracetic acid.

[0003]

Glycidole is a heat-labile substance, and the coexistence of an acid and an alkali remarkably accelerates the polymerization of glycidyl. Therefore, in the conventional purification method in which the reaction crude liquid in which acetic acid is present is distilled as it is, a great loss of glycidol is unavoidable in the distillation column and in the heating section such as the reboiler.

[0004]

OBJECTS OF THE INVENTION The object of the present invention is to provide glycids with acid components.
It is an object of the present invention to provide a purification method for suppressing the polymerization loss of glycol and producing glycidyl in good yield.

[0005]

The present invention has been made to solve the above-mentioned problems, and as a result of intensive studies, glycid-
It has led to the reduction of the loss of the le.

That is, the present invention "adds an ester compound having a boiling point higher than that of glycidol as a diluent to a reaction crude liquid containing glycidol obtained by reacting allyl alcohol with peracetic acid, and Upper glycid
The method for purifying glycidyl is characterized in that distillation is carried out in a state in which the concentration in each stage of the distillation column is reduced.

The point of the present invention is that since the self-polymerization reaction of glycidyl greatly depends on the acetic acid concentration and glycidyl concentration in the system, each concentration was diluted for purification. In this way, rather than hydrocarbons, esters that can be freely mixed with acetic acid or glycidyl were selected as diluents.Esters with a higher boiling point than glycidol were selected so that glycidyl could be a distillate product. There is something I did.

The process for purifying glycidyl is carried out by unreacted allyl alcohol, ethyl acetate (water in some cases) which is a solvent for peracetic acid, a step of removing low boiling point for removing by-produced carboxylic acid, an ester and a side product added with triacetin. It consists of a deboiling process (productization process) for removing raw high-boiling components.

The present invention aims to suppress the polymerization of glycidule by using a diluent in the above-mentioned low boiling point removal step and to reduce the concentration of glycidol near the heating part of the reboiler or the like in the high boiling point removal step. It also has the effect of suppressing polymerization.

The ester used is a carboxylic acid ester having a boiling point higher than that of glycidyl, for example, a monocarboxylic acid ester such as acetic acid ester or propionic acid ester,
Further, esters of dicarboxylic acids such as oxalic acid, malonic acid, succinic acid and glutaric acid are also preferable. Further, diesters of glycols and glycerin triesters are also preferable. The amount of ester as a diluent is 1 with respect to glycidol in the reaction crude liquid.
-20 times the weight, preferably 2-10 times. It is self-evident that the larger the amount of ester, the greater the inhibitory effect on the polymerization of glycidyl due to the dilution effect.
In consideration of separation from the diluent, it is not preferable to add a large amount of diluent unnecessarily.

The diluent may be mixed with the reaction crude liquid before charging it to the distillation column, or may be charged separately to the distillation column. The diluent charging stage may be any stage including the column top and the column bottom, but the crude liquid charging stage to the upper part is more preferable. Glycid
The bottoms of the distillation column for the commercialization of alcohol are diluents and high-boiling components, but most of the high-boiling components are glycid-
Since it is a water-soluble polymer and the ester used as a diluent is poorly soluble in water, it can be easily recovered and recycled by a method such as washing with water.

The effects of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples.

[0013]

EXAMPLES Crude liquid obtained by reacting allyl alcohol / peracetic acid = 3.0 mol ratio (27.2% allyl alcohol)
, 35.6% ethyl acetate, 20.0% acetic acid, 15.2
% Glycidole, 2.0% high boiling point component) and an equal weight of triacetin were added to the distillation column at 100 g / H and the bottom liquid (0.1% acetic acid, 11.7% glycidyl, 85. Two
% Triacetin, 3.0% high boiling point component) 59.6 g /
Obtained in H.

This liquid was charged into a further distillation column and the product glycidyl (containing 0.9% acetic acid) was obtained from the top of the column at 6.8 g / H. The glycidyl yields in the low boiling point removing step and the high boiling point removing step were 90% and 97%, respectively.

[0015]

[Comparative Example] The same reaction crude liquid as in Example was charged into a distillation column at 100 g / H, and the operation was performed under heating conditions such that the acetic acid concentration in the bottom liquid was 1% or less. % Acetic acid, 5
8.3% glycidyl, 40.8% high boiling point component) 1
Obtained at 2.5 g / H. This liquid was charged into a further distillation column, and the product glycidyl (1.6 g / H was added from the top of the column at 7.0 g / H).
% Acetic acid) was obtained. The yields of glycidyl in the low boiling point removing step and the high boiling point removing step were 48% and 95%, respectively.

[0016]

When distilling the reaction crude liquid containing glycidol obtained by reacting allyl alcohol and peracetic acid, the reaction mixture is diluted with an ester having a boiling point higher than that of glycidyl and the glycidyl and By substantially reducing the concentration of acetic acid, it became possible to suppress the polymerization loss of glycidyl and to efficiently manufacture the glycidyl. (Below margin)

Claims (3)

[Claims] 1. An ester compound having a boiling point higher than that of glycidyl is added as a diluent to a reaction crude liquid containing glycidyl obtained by reacting allyl alcohol and peracetic acid, and substantially glycidyl is added. The method for purifying glycidyl, which comprises distilling while reducing the concentration in each stage of the distillation column. 2. The purification method according to claim 1, wherein the reaction crude liquid and the ester are charged into a distillation column from different charging stages. 3. The purification method according to claim 1 or 2, wherein the ester is glycerin triacetate.