SU1310401A1 - Method for removing mono- and dihexylphosphoric acids admixtures from trihexylphosphate - Google Patents

Abstract

This invention relates to the chemistry of organophosphorus compounds, in particular to the purification of trihexyl phosphate (THF) from impurities; mono- and dihexylphosphoric acids, which can be used in the production of plasticizers for ion-selective electrodes. Simplification of the process is achieved by using another rabbi and an alkaline agent. Purification of THF is carried out by diluting technical THF with diethyl ether, followed by treating the mixture with a 1.2-2 fold excess of an aqueous solution of KOH with respect to the impurity content. The method provides obtaining the target products with a residual acid content of 9-10 - 1 10-mol / l. 1 tab. (L: about 4:

Description

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The invention relates to the chemistry of organophosphorus compounds, in particular to an improved method for purifying trihexyl phosphate from mono- and dihexylphosphoric acid impurities, which can be used in the technology of plasticizers for the production of ion-selective electrodes.

The purpose of the invention is to simplify the process.

The invention is illustrated by the following examples.

Example1. 10 ml of trihexyl phosphate containing 0.5 mol / l of acid impurities is diluted with diethyl ether in a volume ratio of 1: 3 and shaken with 10 ml of 1 M potassium hydroxide solution for 1-2 minutes. After delamination, the trihexyl phosphate phase in diethyl ether is washed with an equal volume of water and the diethyl ether is distilled off. The resulting product is isolated into acid impurities by means of extraction photometry using dye dinitrophenol. The content of acidic impurities in the finished product is 2-10 mol / l.

Example 2, 10 ml of trihexyl phosphate containing 0.5 mol / l of acid impurities is diluted with diethyl ether in a volume ratio of 1: 2 and shaken with 10 ml of 1 m potassium hydroxide solution for 1-2 minutes. After delamination, the trihexyl phosphate phase in diethyl ether is washed with an equal volume of water and the diethyl ether is distilled off. The content of acidic impurities in the final product is 510 mol / l.

Example 3. 10 ml of trihexyl phosphate containing 0.5 mol / l of impurities is diluted with diethyl ether in a volume ratio of 1: 1 and shaken with 10 ml of 1 M potassium hydroxide solution for 1-2 minutes. After delamination, the trihexyl phosphate phase in ethyl ether is filled with an equal volume of water and the diethyl ether is distilled off. The content of acidic impurities in the final product is 1-10 mol / l.

Example4. 10 ml of trihexyl phosphate containing 0.5 mol / l of acid impurities is diluted with diethyl ether in a volume ratio of 1: 3 and shaken with 10 ml of a 0.4 M solution of potassium hydroxide for 1-2 minutes. After stratification, the phase of trihexyl phosphate in diethyl ether is washed with rav0401g

a volume of water and diethyl ether are distilled off. The content of acidic impurities in the final product is 9-10 mol / l. Example 5. 10 ml of trihexyl 5 phosphate containing 0.5 mol / l of acid impurities is diluted with diethyl ether in a volume ratio of 1: 3 and shaken with 10 ml of a 0.6 M solution of potassium hydroxide for 1-2 minutes. After delamination, the trihexyl phosphate phase in diethyl ether is washed with an equal volume of water and the diethyl ether is distilled off. The content of acidic impurities in the final product 1-10 mol / l /

 Example 6 10 ml of trihexyl phosphate containing 0.5 mol / l of acid impurities are diluted with diethyl ether in a volume ratio of 1: 3 and shaken with 10 ml of a 2 M KOH solution.

0 for 1-2 minutes After delamination, the trihexyl phosphate phase in diethyl ether is washed with an equal volume of water and the diethyl ether is distilled off. The content of acidic impurities in the final product is 1 10 mol / l.

Data illustrating the dependence of the residual content of acids in trihexyl phosphate on the degree of dilution with diethyl ether, the amount used

The treatment of alkalis, the nature of the diluent and alkali, is given in the table.

Thus, when treating with alkaline solution, boiling in an amount less than equivalent to the content of acids in trihexyl phosphate, the cleaning efficiency is sharply reduced. When processing large

In excess of alkali, cleaning also becomes less effective. When other volatile substances are used as diluents for trihexyl phosphate; solvents (hexane, pentane), the cleaning efficiency is reduced. Purification efficiency is also reduced when using other alkalis (NaOH, LiOH) instead of potassium hydroxide. Reducing the degree of dilution of trihexyl Q phosphate with diethyl ether leads to a decrease in the degree of purification, and an increase in the degree of dilution is impractical because

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Claims (1)

Invention Formula The method of purification of trihexyl phosphate from impurities mono - and dihexylphosphorus31 acid by diluting a technical trihexyl phosphate with a volatile diluent followed by treating the resulting mixture with an alkaline agent solution, characterized in that, in order to simplify the editor I.Slegg Compiled by M.Krasnovska Tehred N. Glushchenko Proof-reader I. Erdeyi Order 1865/24 Circulation 348Subscription VNIZhSH of the USSR State Committee for Inventions and Discoveries 4/5, Zh-35, Raushsk nab. 113035, Moscow Production and printing company, Uzhgorod, Projecto st., 4 3104014 The scientific research institute of the process, diethyl ether is used as a diluent, and 1.2-2-crtt, an excess of an aqueous solution of potassium hydroxide 5 as an alkaline agent with respect to the impurity content.