DD210543A3 - PROCESS FOR THE PREPARATION OF POLYETHERAL COCOOLS - Google Patents

Abstract

The invention relates to a process for the preparation of polyether alcohols based on ring-shaped aliphatic amines, which lead to very good physico-mechanical properties when used in polyurethane foams. According to the invention, this object is achieved by using, as starter substances, mixtures of various piperazines, such as aminoethylpiperazine, hydroxylethylpiperazine and / or diaminoethylpiperazine. These amine mixtures are mixed with alkylene oxide u. possibly reacted in the presence of small amounts of basic catalysts, d. Set the amount of the alkylene oxide according to the composition of the amine mixture.

Description

Title of the invention

Process for the preparation of polyethalcohols

Field of application of the invention .

The invention relates to a process ^{for the} preparation of polyether alcohols, which are suitable mainly for the production of cellular polyurethane materials.

Characteristic of the known technical solutions

A process for the preparation of polyether alcohols by anionically catalyzed polymerization of alkylene oxides with itself or by addition of these alkylene oxides to starter substances having active hydrogen atoms are known. As ötartsubstanzen aliphatic and / or aromatic amines and / or amino alcohols are used for the production of special polyether alcohols for hard or soft polyurethane foams or surface-active substances. The implementation of such ITH-, NH ₂ -funktioneilen 3 t art ses dance s or of HH-, and its derivatives is carried out in a manner customary for the production of polyether alcohol. Since the aliphatic amines or amino alcohols as a result of basic reaction have partially catalytic properties, the reaction with alkylene oxide can take place up to certain molecular weights without the addition of further catalysts. If appropriate, the reactions are carried out in two stages, the customary basic catalysts such as alkalis or alkaline earths being added only in the second stage. As reaction parameters, temperatures of 50 ⁰ C to 150 ⁰ G and pressures of

η π tnr and η η . j _j t \ i \ λ n>

0.1 MPa to 1.0 MPa

For fixing certain final polyether alcohol properties such as molecular weight, functionality and viscosity, the amine starter substances are known to be selected, starter mixtures are used and / or the amount of alkylene oxide is varied. A number of mono-, di-, tri-tetraamines such as diethylenetriamine, ethylenediamine, triethylenetetramine, Hexamethylenediamine or methylamine or amino alcohols such as ethanol or propanolamines used individually or in a particular mixture with each other · To achieve specific polyether alcohol properties, the amines are blended with certain Goinitiatoren and reacted with alkylene oxides, in particular propylene and / or ethylene oxide.

Object of the invention

The aim of the invention is to develop an economical process for the preparation of polyether alcohols based on ring-shaped aliphatic amines for use in cellular polyurethane materials.

Explanation of the essence of the invention

The invention is based on the -Aufgäbe to develop a process for the preparation of polyether alcohols with special properties, which can be processed into polyurethane foams with very good physico-mechanical properties. According to the invention, the object is achieved by using mixtures of various substituted piperazines, such as aminoethylpiperazine, hydroxyethylpiperazine and / or diaminoethylpiperazine, as starting substance for the preparation of the polyether alcohols. In order to vary the properties, additional OH-functional or amino-containing coinitiators may be added to the starting amine mixture, if necessary, and reacted with alkylene oxide. Depending on the amine mixture used and the Alkylenoxid- 'addition the own catalytic ^ effect is supplemented by the addition of small amounts of basic catalysts

Alkylene oxides are mainly used propylene and / or ethylene oxide and these are added individually in succession or as a mixture. The reaction is carried out at temperatures from 80 ⁰ C to 120 ⁰ G, and pressures from 0.1 MPa to 1.0 MPa · The necessary to achieve higher degrees of conversion, depending on the amine used as alkali metal or alkaline earth metal catalysts mixture in an amount of 0.5% to 10% based on the starting mixture used. For the adjustment of certain polyether alcohol functionalities, a special amine mixture with specific contents of substituted piperazines is prepared by rectification and reacted with a matched amount of alkylene oxide. If the alkylene oxide addition is to proceed to higher degrees of conversion, additional catalyst is added at the beginning of the reaction (single-stage) or during the reaction (multi-stage) introduced.

The process according to the invention has the advantage that polyether alcohols with special properties can be prepared by the use of the described mixtures of different substituted piperazines, which can be processed into special products having very good physico-mechanical characteristics. By combining the amine mixture used with the additional catalyst and with specifically metered amount of alkylene oxides, the described form of the reaction is a cost and material-saving polyether alcohol synthesis, which at the same time the fixation of certain desired characteristics, e.g. a high functionality, allows *

The invention will be explained in more detail below using an exemplary embodiment:

embodiment

Into a 1.0 liter autoclave are successively added the mixture of mixtures consisting of 120 g of aminoethylpiperazine, 50 g of hydroxyethylpiperazine and 50 g of bis-aminoethylpiperazine and 1 g of KOH.

filled with nitrogen and the reactor was rendered inert · After heating the Startmischung.auf temperatures of 110 ⁰ C "to 120 ⁰ C starting the .Dosierung of propylene · While maintaining this Eeaktionstemperatur be 550 g of propylene continuously over 2 hours, then metered _o is stirred to a constant pressure at temperatures of 110 ⁰ G and filled after cooling the Hohpolyetheralkohol "By treatment with acid, the KOH are neutralized, then distilled off the water and the resulting salts are removed The polyether alcohol has the following characteristics:

Hydroxyl number = 4? 0 mg KOH / g

pH = 9.7

Water content = 0.05 %

Viscosity at 25 ° G = 5800 mPas

Nitrogen content = 10.8 %

- 5

Claims (1)

~ 5 - Invention claim Process for the preparation of polyether alcohols by base-catalyzed reaction of H-functional starter substances, optionally in the presence of coinitiators with alkylene oxides, in particular propylene and / or ethylene oxide at temperatures of 80 ⁰ C to 120 ⁰ G and pressures of 0.1 MPa to 1 , 0 MPa, characterized in that as starting substances mixtures of different substituted piperazine such as aminoethylpiperazine, hydroxyethylpiperazine and / or diaminoethylpiperazine used, with alkylene oxide and possibly in the presence of small amounts of basic catalysts in consideration of the own catalytic effect of the amine mixtures used to polyether aiko hol is reacted with the amount of the alkylene oxide according to the composition of the amine mixture prepared by rectification.