DD219204A1 - PROCESS FOR THE PREPARATION OF POLYETHERAL COCOOLS - Google Patents

Abstract

The invention relates to a process for the preparation of polyether alcohols, which are suitable mainly for the production of rigid polyurethanes. The object of this invention is to develop a process for the preparation of polyether alcohols based on solid starter substances with high space-time yield and avoiding the use of functional solvents. According to the invention, this object is achieved by reacting polysaccharides such as starch and / or cellulose, which is present in fibrous form or as cellulose powder, and OH- or NH- and / or NH 2 -functional coinitiators, whose properties are the possible addition of catalysts influence, with a partial amount of alkylene oxide, a reaction mixture is prepared which, after removal of unreacted Koinitiatoren or after addition of further, possibly other OH or NH and / or NH2-functional Koinitiatoren and possibly catalysts reacted with the remaining amount of alkylene oxide is, wherein the amounts of the reaction components of the homogeneity of the resulting reaction mixture are dependent.

Description

Title of the Invention · -, ·.

Process for the preparation of polyether alcohols. , Field of application of the invention

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

Characteristic of the known technical solutions

Technically valuable polyurethane foams are produced by the reaction of polyether-alcohols and diisocyanates, whereby mainly the polyether alcohols used characterize the properties and fields of use of the polyurethane foams. Polyether alcohols are known to be synthesized by reacting Η-active substances with alkylene oxides with the aid of basic or acidic catalysts. For use in rigid polyurethane materials. In particular, highly branched polyether alcohols, which are prepared on the basis of OH-functional starter substances such as sugar alcohols, mono-, di- and polysaccharides, are used. Many of these starters are solid and can only be melted via I30 ⁰ G or with decomposition. When using oligosaccharides or polysaccharides, particular auxiliary substances are used, in particular to improve the starting phase. These substances remain during

der.'en entire reaction in the system and can thereby mimic various lifting reactions or by byproduct formation 'deteriorate the' polyether alcohol quality · Furthermore, multi-step process involving the carboxymethylation and subsequent alkylene oxide addition or dispersion in various substances are performed. For this, however, extensive pre-reactions are often necessary, so that the hem-time yields are unfavorable and the product is adversely affected by the multifarious reactions in important key figures. Thus, the applicability of the product is severely restricted for the production of special hydroxyethyl starches or Hydroxyethyl celluloses starters are often foamed only in water and reacted with alkylene oxides by cationic, or anionic reaction mechanism · The sole use of water can lead to the increased formation of low glycols, which unfavorable functionalities and certain properties, such as viscosity, are affected. '. , ... '

Object of the invention . , - /

The aim of the invention is to develop an economical process for the production of polyether-alcohols, based on solid starter substances.

Explanation des.Wesens of the invention

The object of the invention is to develop a process for the preparation of polyether alcohols based on solid starter substances with a high space-time yield and avoiding the use of functional solvents.

- According to the invention, this object is achieved in that by 'reaction of polysaccharides such as starch and / or cellulose, which is present in fibrous form or as cellulose powder, and OH or, NH and / or NH ₂ -funktioniellen Koinitatoren whose properties the possible Addition of catalysts, reacting with a partial amount of alkylene oxide ·

is prepared after removal of unreacted Koinitiatoren or after addition of other possibly OH- or NH- * and / or NHp-funct ioneil he Koinitiatoren and any catalyst addition with the remaining amount of alkylene oxide, wherein the amounts of the Seaktionskomponenten are dependent on the homogeneity of the resulting reaction mixture. The polysaccharides can be used individually or as mixtures with each other. For the process according to the invention, the cellulose in fibrous form, i. H. untreated or after a pretreatment such as hydrolysis and, if appropriate, subsequent mechanical comminution, be used as cellulose powder or microcrystalline cellulose or colloid as oil gel.

Alcohols, sugar alcohols, mono- and disaccharides, especially certain 2- or 3-functional or higher-functional liquid alcohols are used as OH-functional co-initiators. The alcohols are used individually or as a mixture with one another, wherein the mixture is prepared separately or in the production of the alcohols z. B. by AlkoxyIierung of water or other starting substance en s arises. These QH-funktione.llen Koinitiatoren can be used in the basic or neutralized state, in particular ethylene glycol, propylene glycol individually or as a glycol mixture by PropoxyIierung of Η ^, Ο or glycerol are used. Furthermore, polyether alcohols based on OH or NH-functional starters z..B. Glycol or glycerol and alkylene oxide, in particular propylene and / or ethylene oxide are used. These can be completely neutralized and worked up with very different molecular weights, or worked up as basic ones. Rohpolyetheralkohole be used. Low-molecular weight amines or amino alcohols, such as diethylenetriamine, ethylenediamine, triethylenetetramine and analogous alkoxylation products of NH.sub.o, are used individually or as a mixture as NH.sub.2- or NH.sub.2 -functional coinitiators. The alkoxylation can thereby directly after the Alkoxylierungsumsetzung without further. Treatment as a mixture or after distillation treatment and in the form of · the pure substances are used. In mixture with the

ο «g. Köinitiatoren can also be supplied with water · The reaction mixture is at temperatures of 80 ⁰ C to. 15p ⁰ C and pressures of 0.1 MPa to 1.0 MPa reacted with a portion of alkylene oxide. The alkylene oxides used are, in particular, ethylene oxide and / or propylene oxide, which are added to the aliquots both individually, one after the other and / or in the form of a random mixture. The effect of the basic substances used as catalyst, such as alkali and alkaline earth hydroxides or tertiary aliphatic amines such as triethanolamine is combined with the catalytic properties of the NH and / or NHp-functional Köinitiatoren used · By, the implementation of the polysaccharides with the OH, HH and / or NHg-functional Köinitiatoren and a partial

, amount of alkylene oxide formed 'homogeneous or at least pumpable reaction mixtures' which either by the removal of superfluous Köinitiatoren or the addition of other if necessary. Other Köinitiatoren, which in turn affect the need for catalyst addition, modify and react with the remaining amount of alkylene oxide to Rohpolyetheralkoholen. When alkali metal or alkaline earth metal hydroxides have been used as catalyst, these crude polyether alcohols are neutralized with acids as usual, water and other readily volatile constituents are distilled off in vacuo, and the resulting salts are filtered off. ,

^! , The inventive method has the advantage that the combination of polysaccharides with special Köinitiatoren and Alkylenoxidteilmengen a homogeneous or pumpable reaction mixture is formed which with high space-time ^! The koi initiator combination and the component modification make it possible to react solid polysaccharides in the usual conditions of anionic polymerization in good yield. Very advantageous is the possibility of Polyetheralkoholherstellung without the use of water, which always're used in excess and during the reaction, one or more times must be removed. In contrast, the polyether alcohols of the invention can be varied in their quality according to the intended use.

The invention 'will be explained in more detail below on 9 exemplary embodiments:. .

Embodiment 1 .

In a 1.5 1 autoclave successively 100 g of powdered microcrystalline cellulose, 30 g of glycerol and 6g 4-8 % ± ge aqueous KOH filled, under. ^ -Avaporation intensively mixed and to temperatures of 11Ö ⁰ C to-130 ⁰ C. heated. When the temperature is reached, 400 ml of propylene oxide are metered in with vigorous stirring. After completion of the reaction and the addition of 30 g of glycerol, 600 ml of propylene oxide are continuously metered in at analogous temperatures. The mixture is stirred with the reaction mixture and reacted in a post-reaction phase a polyether aiko obtained with the following characteristics: Hydroxylzahr Λ = 500 mg KOH / g.

Acid value = 0, 1 mg KOH / g .. Water content = .0.1 % ' . , ....

pH, = 6.8- '.

Ausführungsbe! "Game 2,;

In a 1.5 1 autoclave 100'g untreated, fibrous cellulose, 60 g of H ₂ O and 3 g of solid KOH are filled, purged with nitrogen and heated with stirring to a temperature of 120 ⁰ C. Thereafter, 300 ml of propylene oxide are continuously metered and reacted by mixing with the starting substance. After this propylene oxide is completely .reacted, the reaction mixture is distilled in vacuo to remove unreacted water and the resulting lower glycols. Subsequently, a further 800 ml of propylene oxide are continuously metered in and, after the metering, stirred for further reaction. After the usual purification, a polyether alcohol is formed having the following characteristics: hydroxyl number = 440 mg KOH / g water content. = 0.1 % pH = 6.5

, , , Embodiment 3

In a 1.5 1 autoclave 100 g of cellulose, 60 · SH ₂ O and 3 g of solid KOH are filled and heated after flushing. With nitrogen to a temperature of 120 ⁰ C. After that. 7 / erden 1100 ml of propylene oxide metered ,. Stirred with the reaction mixture and completely reacted in a post-reaction phase. After cleaning, a catalyst is produced with the following characteristics:, ',. , , , "

.HydroxyIzaiii = 600 mg KOH / g. , _

Water content = 0.1 % , ''

Viscosity = 7.0 " ",

Embodiment 4 .. '''

In Binen 1 ₁ 5 1.Autoklaven'werden 100 g of cellulose, 30 g Triisopropanolamiii and 4 g of aqueous 48% KOH filled, flushed with nitrogen, heated to a temperature of 12.0 ⁰ C and 'after DEM Sindosieren of 400 ml of propylene oxide with this implemented. Thereafter, another 20 g Triisopropanol-. In the reaction of this mixture with a further 400 ml of propylene oxide, the temperatures are set to values of from 100 ^° C. to 120 ^° C. The polyether alcohol has the following characteristics after customary purification:. Hydroxyl number = 480 mg KOH / g water content ' => 0.1 '% Viscosity = 8.8 ^:

Embodiment 5

In a 1.5 1 autoclave 100 g of starch, 50 g of glycol mixture is filled with a larger proportion of lower glycols based on water and propylene oxide and 3 S solid KOH, purged with nitrogen, heated to a temperature of 120 ⁰ C and reacted with 400 ml of propylene oxide. After complete Propylenoxidpolymeräsation another 30 g of glycol mixture are introduced and then 400 ml of propylene oxide

The resulting crude polyether alcohol is purified in a customary manner from the catalyst and then has the following characteristics:

Hydroxyl number = 430 mg KOH / g

Acid number = 0.1 mg KOH / g. , pH s 6.2

Embodiment 6 . ,

In a 1 »5 1 autoclave 100 g of pretreated microcrystalline cellulose and 60 g of NH ^ -Wasser filled, after purging with nitrogen and heating to a temperature of 120 ⁰ O successively metered 400 ml of propylene oxide and reacted. After complete reaction, 2 g. fed solid KOH, again metered at temperatures of 110 ⁰ C to 130 ⁰ O 500 ml of propylene oxide and completely reacted by a post-reaction phase After cleaning, the polyether alcohol has the following characteristics: hydroxyl number s 590 mg KOH / g water content = 0, 1 % pH = 9.8 ''

Embodiment 7 -.

In a 1.5 1 autoclave, 100 g pretreated microcrystalline cellulose and, 60 g NHv-filled water, after purging with nitrogen and heating to a temperature of 120 ⁰ C successively metered 400 ml of propylene oxide and reacted · The reaction mixture is removed Subsequently, 2 g of solid KOH are fed, at temperatures of 110 ° C to I30 ⁰ C again 500 ml Propylehoxid metered and brought to a complete reaction by a Nachreaktiönsphase of unreacted water and resulting low glycols in vacuo. After cleaning, the polyether alcohol has the following characteristics:

Hydroxyl number 3 510 mg KOH / g.

Water content = 0.1 % ⁱ

pH = 10.0. ^; ,

... - 8 - Embodiment 8 : '. :

In a 1.5 1 autoclave 30 g of cellulose, 30 g of dextrin, 30 g of sucrose, 20 g of triisopropanolamine and 6 g of aqueous 48% KOH filled, rendered inert with nitrogen and heated to a temperature of 110 ⁰ C to 130 ^{0 /} C. Then 1200 ml of propylene oxide are metered in and brought to a boil by intensive mixing. The subsequently purified polyether alcohol has the following characteristics: hydroxyl number = 400 mg KOH / g.

Water content = 0.1 % - .. '... pH = .8,5 ':

Embodiment 9 .

In a 1.5 1 autoclave 40 g of cellulose, 40 g of sucrose, 40 g of glycerol, 5 g of water and 3 g KOH filled under nitrogen atmosphere intensively mixed together, heated to a temperature of 110 ⁰ C to 120 ⁰ C, 400 successively ml Propyleno2 ± d.eindosiert, intensively mixed with the starting mixture and reacted at the reaction temperatures. Subsequently, unreacted water and volatile glycols are distilled off · In the reaction mixture at temperatures around 120 ⁰ C, a further 600 ml PropylenoxLd 'continuously metered. After the reaction and purification, ¹ gives a polyether alcohol having the following characteristics: hydroxyl number = 490 mg KOH / g. ;

Water content '= 0.1 % pH = 6.9

Claims (4)

- 9 ~. "Erfindungsansprüc he 1. A process for the preparation of PoIyetheralkoholen »characterized in that 'by reacting polysaccharides such as starch and / or cellulose, which is present in fibrous form or as a cellulose powder, and OH or, NH and / or HElj-füktionellen Koinitiatoren whose Properties the possible. Addition of catalysts influence, with , a subset of alkylene oxide, a reaction mixture is prepared, which is reacted after removal of unreacted Koinitiatoren or after addition of further, optionally other OH or, WH and / or NHp-functional Koinitiatoren and any catalysts with the residual amount of alkylene oxide, wherein the amounts of the reaction components of the homogeneity of the resulting reaction mixture are dependent «. . 2. The method according to item 1, dadureh characterized in that are used as QH-functional Koinitiatoren Dioie, triols or higher 'functional liquid alcohols »· · 3 · Method according to item 1 and 2, dadureh characterized in that the OH-functional Koinitiatoren be used individually or in a mixture with each other, wherein the mixture is prepared separately or in the preparation of the alcohols, for example by *. Alkoxylation of water or other otartsubstanzen arises and is used in the basic or neutralized state. 4, Verfahren.nach point 1, dadureh characterized in that are used as NH or NHg-functional co-initiators, preferably non-, dermolekulare amines or amino alcohols such as diethylenetriamine, ethylenediamine, triethylenetetramine or triisopropanolamine and analogous alkoxylation3 products of NHo individually or as a mixture.