DD211797A1 - PROCESS FOR THE PREPARED PREPARATION OF POLYETHERAL COCOOLS - Google Patents

Abstract

The invention relates to a process for the stepwise preparation of polyether alcohols, which are mainly suitable for the production of hard polyurethane foams. According to the invention, this object is achieved by the fact that in the first stage of the process, the solid or highly viscous starting substance with a combination of a basic inorganic catalyst, in particular KOH, and a catalyst u. Co-initiator combines acting. Substance such as NH 3 and / or its Propoxylierungsprodukteversetzt and is reacted with a partial amount of alkylene oxide, then unreacted water and lower glycols are removed by distillation and the remaining amount of alkylene oxide in the second stage is added, optionally with a further amount of the catalyst and / or a substance acting as a catalyst and coinitiator can be added.

Description

Title of the invention

Process for staged iron production of polyether alcohols

Field of application of the invention ;

The invention relates to a process for the step-iron preparation of polyether alcohols, which are mainly suitable for the production of rigid polyurethane foams. «

Chara kteristik hang the bek annten technical Solu

Processes for the preparation of polyether alcohols by polymerization of alkylene oxides with themselves or by addition of these alkylene oxides to starter substances having active hydrogen atoms are known. The starting substances, alkylene oxides, catalysts and reaction conditions are selected according to the later field of use of the polyether alcohols. Purely the production of rigid polyurethane foams are on the one hand higher-functional alcohols, sugar alcohols and / or saccharides such as pentaerythritol, sorbitol, xylitol, glucose, sucrose and on the other hand nitrogen-containing starter substances such as HH ^ , aliphatic and aromatic polyfunctional amines bzvj. Used amino alcohols and reacted with propylene and / or ethylene oxide in the presence of basic catalysts at temperatures of 90 ⁰ C to 130 ⁰ C and pressures of 0.1 MPa to 1.0 MPa. Especially in the implementation of solid bzia. high-melting sugar alcohols]! or saccharides such as. E, in sucrose starter substance mixtures are used. The coinitiators used have a limited ability to dissolve the solid starting substance

and to the supplied alkylene oxides. "Processes are also known in which a solvent / water is used in addition, but polyglycols form therefrom which severely impair the use of the polyether alcohols as a result of a deterioration in functionality. The use of coinitiator combination or the use thereof The starting phase can also be homogeneous or heterogeneous * Amines are also used for the reaction of sugar alcohols or "saccharides." Certain processes use amine catalysts, in which triethylamine is used in particular is the difficulty in the quantitative removal from the polymers «Furthermore, the use of amines or amino alcohols as Koinitiatoren possible, it z _a B * diethylenetriamine and triethanolamine are used and added to the starting mixture in different amounts, however, these amines have no or only a minor effect on the system _e

Object of the invention

The aim of the invention is to develop an economical process for the stepwise preparation of polyether alcohols based on solid starting substances for use in rigid polyurethane foam systems.

Explanation _n (JeS ₁ essence of invention

The object of the invention is to develop a process for the stepwise preparation of polyether alcohols by reacting solid starting substances with alkylenesides in the presence of a catalyst / coinitiator combination.

According to the invention, this object is achieved in that, in the first stage of the process, a solid or highly viscous starter substance is mixed with a combination of a catalyst and a substance acting as catalyst and coinitiator and reacted with a partial amount of alkylene oxide. , high-viscosity starter substance are sugar alcohols

and / or saccharides, in particular sucrose used without special pretreatment. The catalyst used in the combination is a basic inorganic compound, preferably an alkaline earth compound such as KOH, K ₂ COO, Ca (OH) -. This catalyst is used in combination with a combined catalyst and coinitiator such as ammonia and ammonia or propoxylation products of ammonia, in particular monoisopropanolamine, diisopropanolamine, triisopropanolamine, these products being optionally prepared in a preliminary stage of the process by reacting aqueous 2TEU solution with propylene oxide and used singly or in admixture with one another or as an aqueous solution. Ss is possible UH-, in the various aggregate states such as gaseous, liquid or use as an aqueous solution. The quantitative mixing ratio between solid or high viscosity starting material and the coinitiator / catalyst combination is 20; 1 to 1: 1. The starting substance / catalyst / Koinitiatoi combination is mixed at temperatures of 40 ⁰ C to 120 ⁰ C and pressures of 0.1 MPa - 1.0 MPa and after 3S ₂ -Inertisierung in the 1st stage with a partial amount of alkylene oxide implemented. Thereafter, by vacuum distillation or =. Hp stripping removes unreacted water or lower glycols. In the subsequent 2nd stage of the process is at temperatures of 60 ⁰ C to 120 ⁰ G and at pressures of 0.1 MPa to 1.0 MPa necessary to achieve the desired molar weight of residual amount of alkylenoside, in particular propylene and / or Ethylene oxide metered and deposited »For further variation of the properties, in particular the viscosity and reactivity in the second stage of the process may be added before the addition of alkylene oxide, if appropriate, a further amount of catalyst and / or a combined acting as a catalyst and Koinitiator acting substance. After completion of alkylene oxide addition and a liachreaktionszeit at temperatures around 100 ⁰ C, the alkaline polymer is worked up by addition of inorganic or organic acids or ion exchangers, by distillation under vacuum or stripping with nitrogen and filtration of the resulting salts *

The inventive method has the advantage that the combined .Anwendung of catalyst and Koinitiator a controlled alkylene oxide addition is possible and thereby a polyether alcohol can be prepared, which is based on a higher functional sugar alcohol or saccharide and on the other on an aliphatic amine The solid or high-viscosity starting substance can be used by the process according to the invention without further pretreatment and can be reacted in a very good reaction rate in a homogeneous or heterogeneous but stirrable and free-flowing reaction mixture. The possibility of a subsequent metering of the catalyst / Koini tia torkombination the nitrogen content of the polyether "·» alcohols can be controlled in a wide range · In addition, in particular the reaction start and the first reaction phase take place at high speed, so that all otherwise usual aids are omitted at this point and the additionally occurring undergoing reactions, such as the formation of polyglycols are very suppressed * This results in only minor puncture damage by the lifting products »

The invention will be explained in more detail below on 5 exemplary embodiments »

Example 1 .:

After inerting with nitrogen, 4000 g of aqueous 25% strength solution, 250 g of aqueous KOH solution and 6800 g of sucrose are introduced successively into a 50 l reactor. While stirring, the starting mixture is heated to temperatures of 50 ⁰ C to 70 ⁰ C. Thereafter, in the first stage of the process, an amount of 13 kg of propylene oxide is metered in, the temperature being brought to values of max. 100 ⁰ C and a pressure of 0.5 MPa increases, after a one-hour IJachreaktion for stabilization, the reaction mixture is stripped for 4 h with inert gas to remove the 'barrel and then metered in the 2 × process stage further 19 kg of propylene oxide and at temperatures of 100' C annealed to 120 ⁰ C "laughing a short Uachreaktionszeit is

the crude polyether obtained is neutralized by adding aqueous phosphoric acid, the volatile constituents are distilled off and the resulting salt is filtered off. The finished polyether alcohol has the following characteristics:

Hydroxyl number = 480 mg KOH / g

Viscosity at 25 ⁰ C = 7000 m Pas

pH = 10.4

Water content = 0.05 %

Ausführun gsbeispiel 2t

3200 g of H ₂ O, 120 g of solid KOH and 7000 g of sucrose are introduced successively into a 50 1 reactor with stirring. While cooling the reactor jacket and stirring the starting mixture 1000 g ϊίΗ, gas-added. Heated after a stabilization phase Y? Ith the starting mixture to temperatures "of 50 ⁰ C to 70 ⁰ G. After a pressure increase to 0.6 MPa and a temperature increase to about 100 ⁰ C v / ground ± 1st stage n 14 kg Propylanoxid . after a metered Uachresktionszeit and from "distill the water 19 kg propylene oxide are * eindcsiert and annealed at a temperature of about" 100 ⁰ C in represents 2, step * after customary working the resulting polyether has the following characteristics:

Hydroxy! Number = 460 mg KOH / g

Viscosity at 25 ⁰ C = 8000 m Pas

pH = 10.2

Water content = 0.1 %

A usführun gsbeisp iel 3 s

In a 50 1 - reactor 3.4 kg aqueous 25% UH solution are filled and at temperatures of 30 ⁰ C to 50 ⁰ C ervsärait. Thereafter, "ground 8700 g of propylene oxide are metered in continuously and the reaction at temperatures from 90 ⁰ C to 100 ⁰ C., After this reaction, the HH ₀ to Tripropanolaaiin

6800 g of sucrose and 220 g of aqueous potassium hydroxide solution are introduced and continuously at temperatures of 100 ⁰ C 6.0 kg of propylene oxide were metered _β Then, in the present reaction mixture, the reaction mixture 1 _e stage is dried by distillation, and in the 2 'stage 15 kg of propylene oxide were metered and brought to reaction at temperatures of 100 ⁰ C to 120 ⁰ G * Hach afterreaction and a conventional cleaning results in a polyether alcohol with the following characteristicsi_

Hydroxyl number = 490 mg KOH / g viscosity at 25 ^° C. = 9000 a pas pH = 10.1

Embodiment 4?

In a 70 1 - reactor 2 _S 8 kg HpO 35 kg aqueous KOH are charged and filled at temperatures of 20 C to 30 ⁰ C 13.5 kg of sucrose, then 900 g HH ^ liquid introduced into the mixture and mixed with stirring, lach heating to a temperature of 50 ⁰ G to 70 ⁰ C are continuously metered in the first stage 20 kg of propylene oxide with intensive mixing. Kach a short stabilization phase, the water and lower glycols are distilled off and then in the 2e phase 26 kg of propylene oxide at temperatures of 100 ⁰ C to 120 C deposited »Hach a Hachreaktionsphase and the cleaning produces a Polyetheralkohol with the following characteristic numbers;

Hydroxyl number = 530 mg KOH / g

Viscosity at 25 ⁰ C = 18000 m Pas

pH = 10, .1

Water content = 0.1 %

Embodiment 5 *

In a 70 1 - reactor 7 kg of aqueous 25% UH ~ solution are filled, metered to 90 ⁰ C and continuously metered and reacted 17.5 kg of propylene oxide. In this aqueous Tripro

Panolamine solution are charged with 6.8 kg of sucrose and 300 g of aqueous KOH solution and metered at a temperature of 100 ⁰ C 6 kg of propylene oxide, after distilling off the water in the second stage 23 kg of propylene oxide are fed continuously and at temperatures of 100 ⁰ C to 120 ⁰ C and pressures up to 0.4 MPa attached. After stabilization and customary purification of the polymer from the KOH, a polyether alcohol is formed with the following characteristics:

hydroxyl 25 ⁰ o = 440 mg KOH / g Viscosity at = 3500 m Pas PH value = 10.7

Claims (4)

Srfindungsansprüche 1, Process for step iron Production of polyether alcohols by reacting a solid or high viscosity starter substance, a Koinitiator / catalyst combination at temperatures of 40 ⁰ G to 120 ⁰ C with alkylene oxides, in particular PO and / or EO, characterized in that in the 1, stage the process, the solid or "highly viscous starting substance with a combination of a basic inorganic catalyst, in particular KOK, and combined acting as a catalyst and Koinitiator acting substance such as EEU and / or its Propoxylierungsprodukte and reacted with a partial amount of alkylene oxide is, then unreacted Water and lower glycols are removed by distillation and the remaining amount of iklkylenoxid is attached in the 2nd stage, where appropriate, an additional amount of the catalyst and / or a combination acting as a catalyst and Koinitiator acting substance can be added « 2. Method according to item 1, characterized in that the mixing ratio between solid or highly viscous starting substance and the coinitiator / catalyst combination is 20: 1 to 1: 1. 3 · The method of item 1 and 2, characterized in that IFeL gaseous, liquid and / or as? ^»! Aqueous solution can be used 4. The method according to item 1 and 2, characterized in that are used as propoxylation of the NK «preferably Monoisopropanolainin, diisopropanolamine, T-riisopropanolamin, which are optionally prepared in a precursor of the process by reacting aqueous ΪΙΗ -, solution with propylene oxide and individually or mixed with one another or used as an aqueous solution