DD155780A3 - CONTINUOUS METHOD OF SEPARATING EPOXY RESIN-SOLVENT MIXTURES - Google Patents

Abstract

Continuous process for the separation of epoxy resin-solvent mixtures from epoxy resin reaction mixtures. It should be used space-saving equipment and reduce the amounts of combustible solvents. The separation should be made more economical and efficient. This is achieved by separation at temperatures of 30 to 70 degrees C and at centrifugal accelerations of 2000 to 15000 g within 2 to 40 seconds.

Description

202574

VEB Leuna-Werke 42 Merseburg, 7. 12 · 1977

«Walter Ulbricht» DG; Hl / Squall

LP 7790

Title of the invention

Continuous process for the separation of epoxy resin solvent creams

Field of application of the invention

The invention relates to a process for the continuous separation of epoxy resin solvent mixtures from in the reaction of 2,2-bis (p-oxyphenyl) propane (hereinafter called bisphenol A, epichlorohydrin and aqueous Alkalihydosoxidlösung and solvent-containing reaction mixtures ^

Characteristic of the known technical solutions

It is known that epoxy resins consisting of glycidyl polyethers which are used in the reaction of epichlorohydrin, a polyhydric phenol, e.g. As bisphenol A, and arise from aqueous alkali metal hydroxide solutions of different concentrations, by extraction with an organic solvent., Which practically does not mix with water, can separate from the rest of the reaction mixture; One of the forming phases consists of the epoxy resin and the solvent,

20257Д

77Р 7790

another phase contains water, inorganic salts dissolved in water, and most unknown yellowish impurities, while the third phase contains test portions such as unreacted bisphenol A, catalyst origin, and solid impurities of unknown type;

The separation can be carried out in a separator (DT-AS 1131413) or by decantation (DT-AS 1545071, DT-AS 1645541). The rear part of this procedure is that the separation of the phases requires a considerable amount of time and the installation of large-volume containers as separation devices. Thus, decanting in the method described in DT-AS I645541 claims a period of 10 minutes. In addition, because of the preferably used combustible solvents in this procedure, sources of danger that can only be eliminated by additional technical expenses.

Object of the invention

The aim of the invention is to separate epoxide resin solvent mixtures using space-saving apparatuses and, to increase occupational safety, with small amounts of combustible liquids with low technical outlay more effectively and cost-effectively from epoxy resin heatsurfaces.

Explanation of the essence of the invention

It is advantageous to "work in the reaction of bisphenol A, epichlorohydrin and aqueous alkali metal hydroxide solution to form epoxy resin by a continuous process." In order to be able to work up the reaction product obtained in a suitable manner, the separation stage in which the epoxy resin is an aqueous solution and one

202574

LP 7790

In previously described processes for working up on epoxy resin reaction mixtures, the separation is carried out in a continuous or discontinuous manner in separators! The Vervieilzeit in these devices is relatively'.lang and is for example in the method described in DT-AS 1645541 10 minutes; In less than ¹⁰⁺ , sufficient phase separation does not occur; At the usual on-scale throughputs, this requires the installation of large-volume settling tank. In addition, because of the preferably used combustible solvents in this procedure, sources of danger, which can only be eliminated by additional technical expenses. + Minutes.

It was the task of a more effective method for the separation of Epoxidharz-LösungsTuittelgemischen from epoxy resin-Beaktionsgemischen containing in addition to epoxy resin, a water-immiscible solvent, water, inorganic salts, unreacted bisphenol A, catalyst residues and impurities of unknown type, which allows continuous work; The ratios of epoxy resin to solvent and epoxy resin solution to water correspond to the conditions that occur in the Epoxidharzherstelluns.

The epoxy reaction mixture is. According to the invention at a temperature of 20 to 95 ° 0, preferably 30 to 70 ⁰ O, continuously passed through a Seperator and in this with a centrifugal acceleration of 2000 to 15000 g, preferably 3000 to 7000 g, in a time of 2 to 40 seconds divided into 3 phases. One phase consists of an epoxy resin solvent mixture, another of inorganic salts dissolved in water, as well as dissolved impurities of unknown type and the last of solid components, such as bisphenol A, catalyst.

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torrests and solid impurities of unknown kind.

The difference in densities of the epoxy resin solvent phase and the aqueous phase must be at least 0.005 g / ml. As the solvent, xylene, toluene, itethyl isobutyl ketone or diisopropyl ketone can be used.

Embodiment Example 1

100 parts by volume / h of a reaction mixture consisting of 10 parts by volume of epoxy resin, 20 parts by volume of xylene and 70 parts by volume of bisphenol A, inorganic salts, catalyst residues and impurities of unknown type are continuously introduced into a separator at a temperature of 45 ^° C. injected, which operates with a centrifugal acceleration of 4000 g; Hach a residence time of. 25 seconds are obtained in the first phase, parts by volume / h of epoxy resin and 20'volumiles / h of xylene, in the second phase 69.5 parts by volume of water, inorganic salts dissolved in water and dissolved impurities of unknown type and in the third phase 0.5 parts by volume / h bisphenol A, catalyst residues and solid impurities of unknown type. While the 1; and the second phase are in liquid form, the third phase is аодэ solids. The density difference between the 1st and 2nd phase is 0.05 g / ml.

Example 2:

100 parts by volume / h of a reaction mixture consisting of 15 parts by volume of epoxy resin, 15 parts by volume of diisopropyl ketone and 70 parts by volume of water, bisphenol A, inorganic salts, catalyst residues and impurities of unknown type are continuously injected at a temperature of 75 ° C. in a separator which is charged with egg -

202574

LP 7790

After a residence time of 20 seconds, 15 parts by volume / h of epoxy resin and 15 parts by volume / h of diisopropyl ketone are obtained in the 1i phase and 69 parts by volume / h of water in the 2І phase, dissolved in water ₃ inorganic salts and dissolved impurities of unknown type and in the ЗІ phase 1 part by volume / h of bisphenol A, catalyst residues and solid impurities of unknown type; while the 1, nd and 2; phases are in liquid form, the У phase consists of pesticide eni The difference in density between the 1st and 2nd phase is 0.150 g / ml.

Claims (2)

202574 77Р 7790 Invention pruohoh 1. A continuous process for the separation of Epoxidharz Lb'sungsmittel aemisehen from epoxy resin reaction mixtures containing in addition to epoxy resin with a Viasser immiscible solvent, water, inorganic salts, unreacted bisphenol A, catalyst residues and impurities of unknown type, characterized in that the reaction mixture bit of a temperature of 20 to 95 ⁰ C, preferably 30 to 70 ⁰ C, passed through a separator and in this with a centrifugal acceleration of 2000 to 15000 g, preferably 3000 to 7000 g, within 2 to 40 seconds in one phase composed of an epoxy resin solvent mixture, another phase consisting of water, inorganic salts dissolved in water and dissolved impurities of unknown type, the density difference between these two phases being at least 0.005 g / ml and finally a phase consisting of solid components, such as unreacted bisphenol A, catalyst residues n and solid impurities of unknown kind, consists, is decomposed. 2. The method according to item 1, characterized in that xylene, idluol, methyl isobutyl ketone or diisopropyl ketone are used as the solvent.