DD216247A1 - METHOD OF PREPARING POLYETHERAL COCOOLS - Google Patents

Abstract

The invention relates to a preparation process of polyether alcohols which are suitable for use in rigid polyurethane foams. The object of the invention is to develop a production process of polyether alcohols while establishing a favorable Viskositaetsbereiches along the entire synthesis. According to the invention, this object is achieved by using as the starting substance an acid-catalyzed and optionally neutralized condensation product of specific alcohols having a variable degree of condensation individually or in admixture with other condensation products and solid coinitiators and / or inert and / or functional solvents or agents; and the reaction with alkylene oxides is carried out in one or more stages, the addition of the condensation products or of the inert and / or functional solvents or disintegrants being carried out once or several times from or after the first or any further alkylene oxide stage.

Description

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Title of invent

Production process of polyether alcohols

Field of application of the invention

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

Characteristic of the known technical solutions

The preparation of polyether alcohols by reaction of H-funktioriellen starting substances with alkylene oxides by anionic or cationic mechanism in the presence of the respective necessary catalysts and using appropriate reaction conditions has long been known · lifting "the use of liquid starters, the good start of the reaction, a safe reaction and a high space / time yield is possible, solid or high-melting functional starters are used in particular for the production of rigid polyurethane materials. For the production of special polyol types, in particular for increasing the crosslinking density, it is necessary, for example, to use polysaccharides or higher-functional amines. The implementation of such substances prepares in the usual stirred or circulation reactors because of poor alkylene oxide solubility and low heat conductivity considerable difficulties · To improve the homogeneity during the start or reaction phase Inert or functional solvents or coinitiators are added. Because many of the highly functional starter substances

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are only sparingly soluble, the solvent must be used in an excess earth and be removed again consuming after the Polyetheralkoholsynthese. If functional solvents are used, there is also a risk that the solvent will co-react and the resulting addition compounds will introduce undesirable properties such as, · B, loss of functionality into the polyol. When using coinitiators, the starting mixture is only partially homogenized and it can thus be carried out with a favorable choice of parameters a controllable reaction start. However, the known coinitiators such as 2- or 3-functional parts alcohols or amino alcohols have z. As glycerol or TPOA when used in high-melting and high-viscosity starters often only a very small effect on the homogenization and the viscosity of the finished polyether, so that their proportion must often be increased excessively or other auxiliaries must be added ·

Object of the invention

The aim of the invention is to develop an economical production process of polyetheralkotiols based on OH-functional starter substances.

Explanation of the essence of the invention .

The invention has for its object to develop a production process of polyether alcohols under adjustment of a favorable viscosity range along the entire synthesis. According to the invention the object is achieved in that a starting substance mixture of a special OH-functional condensation product and a solid Koinitiator with alkylene oxide is implemented in one or more stages. As sty substance acid-catalyzed and optionally neutralized condensation products of special alcohols, in particular from 1,3-butanediol used. These can individually or with other condensation products with a certain degree of condensation based on alcohols, in which each 2 QH groups of the alcohol molecule not

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are connected via a chain of 4 or 5 carbon atoms, in particular hexanediol-1.6, neopentyl glycol, glycerol or TMP are used. In the preparation of the condensation products, it is possible to produce and use products with different degrees of condensation by varying the residence time and the catalysis. The condensation is ζ · example by means of H ₂ SO ₄ catalyzed Siert and the condensation products used for the polyether-Hersteljlung either unbehanjdelt, d. used acidic or they are neutralized prior to use by means of alkali hydroxide, in particular NaOH or KOH · When using acidic condensation products to ensure a good reaction rate in the Alkylenoxjid addition, the amount of basic catalyst to the part! the residual acid can be increased. Solid co-initiators may be solid OH-functional substances, in particular 3- or 4-functional alcohols such as pentaerythritol or Möherfunktionelle oligosaccharides such as starch, cellulose or lignin are used. As solid coinitiators, it is also possible to use esthetic HH or UH "-functional and / or combined OH and NH-functional substances, such as special aliphatic, cycloaliphatic or aromatic amines and / or amino alcohols, in particular urea, their derivatives and reaction products or special propanolamines be used.

The star substance mixture of OH-functional condensation products and solid coinitiators can be mixed before the alkylene oxide addition and then reacted with alkylene oxides in one or more stages. The alkylene oxides used are in particular ethylene oxide and / or propylene oxide. However, the addition of the OH-functional condensation products can also take place several times, even before or after the first or any further alkylene oxide stage. In the case of extremely high-viscosity reaction mixtures, it is possible to use optional and / or functional solvents or diluents which are likewise added one or more times before or after the 1st or any further alkylene oxide stage in particular liquid alkanes or aromatic solvents such as hexane, heptane, toluene or others

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Used as functional solvents or diluents are 2- or 3-functional alcohols and / or polyfunctional amines or amino alcohols or HpO or γ-water.

The one- or multi-stage reaction of the starter substance mixture with alkylene oxides is carried out according to the usual anionic mechanism conditions such as temperatures from 60 ⁰ C to 130 ⁰ C and pressures of 0.1 MPa to 1.0MPa, To accelerate the reaction basic catalysts are added, in particular, alkali metal and alkaline earth metal hydroxides are used and are used in an amount of 0.05 % to 0.5% in the perphered polyether alcohol. Depending on the composition of the starting mixture, the amount of catalyst is varied and the addition adapted. When using solid KH- or NH ^ -functional amines or amino alcohols can be used as a result of ajotokataIytischer effects a small amount of catalyst or the catalyst can be added only in the second or another alkylene oxide stage. In the case of multistage alkylene oxide addition, the part of the unreacted functional solvent or part or all of the inert solvent can be removed by vacuum distillation after the 1 × stage.

After addition of the entire amount of alkylene oxide Rohpolyetheralkohol for Mach reaction is stirred for some time at temperatures around 100 ⁰ C and then the catalyst is neutralized by addition of acid. The water present and the resulting salts are removed by vacuum distillation and filtration. , ,,

The process according to the invention has the advantage that the use of a starting substance mixture of an OH-functional condensation product and the further added solid initiators makes it possible to set a viscosity range which is favorable both for the start of the reaction and for the entire reaction range and the pertiglypolyether alcohol. By varying the starting substance composition and the possibility of adding inert or functional solvents, a homogeneous state can be made possible over a wide temperature range, whereby the alkylene oxide addition can be carried out in a favorable space-time yield. With the

On the one hand, high-grade polyether alcohols can be prepared by using the various condensation products and, on the other hand, by varying the degree of condensation, it is possible to save alkylene oxide and it is possible to increase the variant width of the polyether alcohol properties with the same starting chemicals.

The invention will be explained in more detail below on * .j 5 embodiments:

Embodiment 1

In a 1.5 1 autoclave with stirrer, temperature and pressure measurement and a pump for alkylene oxide metering are successively 100 g of starch and 100 g of a condensation product of butanediol-1.3 »was neutralized after the acid-controlled condensation using alkali hydroxide, and 3 g solid KOH filled and then the autoclave is flushed with N «and brought to a temperature of 110 C. After the temperature has been reached, 800 ml of propylene oxide are continuously metered in with good mixing of the reactants, the pressure increasing to a value of 0.7 MPa. After metering, the reaction mixture is still intensively mixed for lachrymation. The poly-, etheralkohol is then freed as usual by acid neutralization, distillation nuid filtration from the catalyst. The resulting PAA has the following key figures:

Hydroxyl number = 500 mg KOH / g

Acid number = 0.1 mg KOH / g

Water content = 0.1 %

Embodiment 2

In a 1.5 liter autoclave, 300 g of an acidic and neutralized condensation product of butanediol, 1.3, 100 g of cellulose, wherein both untreated cellulose and pretreated, in particular microcrystalline, cellulose can be used, 6 g 48% aqueous KOH Solution and 50 g of hexane filled, rinsed with Ng and to a temperature of

120 ⁰ C heated. Each time the temperature is reached, 200 ml of ethylene oxide and then 700 ml of propylene oxide are metered in and, during the metering and during the subsequent stabilization phase, stirred intensively with the reaction mixture. After the usual catalyst removal, a polyether alcohol is formed with the following characteristics:

Hydroxyl number = 560 mg KOH / g ^;

Acid number = 0.1 mg KOH / g

Water content = 0.1%

Embodiment β

In a 1.5 1 .- autoclave 250 g of lignin sulfonate and 50 g acid-condensed reaction product of 1,3-butanediol filled, rendered inert with U ₂ and heated to a temperature of 130 ⁰ C. Thereafter, 200 ml of propylene oxide are metered in, and then existing oil is distilled off and 6 g of solid KOH are introduced and further reacted with 500 ml of propylene oxide. After purification from the catalyst, a polyether alcohol is formed with the following characteristics:

Hydroxyl number = 600 mg KOH / g

Acid number = 0.1 mg KOH / g

Water content * 0.1 %

Implementation Example 4

In a 1.5 1 - autoclave 50 g of an acidic condensation of butanediol-1.3 prepared and neutralized product and 50 g of an analogously prepared and neutralized product of hexanediol (1.6) and 250 g urea filled, inertized with N ₂ , to a Temperature of 120 ⁰ C heated and mixed with 100 ml of propylene oxide. Thereafter, 3 g of solid KOH are charged and at the reaction temperature of 120 ⁰ C, a further 700 ml of propylene oxide are metered. As a result of a post-reaction phase and the removal of the catalyst by acid neutralization, distillation and filtration, a polyether alcohol is obtained having the following characteristics:

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Hydroxyl number = 600 mg KOH / g acid number = 0.1 mg KOH / g water content = 0.1 %

Embodiment 5

In a 1.5 liter autoclave, 200 g of an acidified and neutralized condensation product of butanediol 1-3 are charged with 300 g of pentaerythritol and 4 g of solid KOH, rendered inert with W ₂ and heated to a temperature of 120 ^° C. After reaching the temperature, 800 ml of propylene oxide are metered in and mixed with good mixing. After a Uachreaktion and the purification of the catalyst produces a polyether alcohol with the following characteristics:

Hydroxyl number = 650 mg KOH / g

Acid number .. «0.1 mg KOH / g

Yeast content = 0.1 SS

Claims (4)

SrfindungsanSprüche 1 · Preparation of polyether alcohols based on OH-functional starter substances by base-catalyzed reaction at temperatures of 60 ⁰ G to 130 ⁰ C and pressures of 0.1 MPa to 1.0 MPa with alkylene oxides, preferably ethylene and / or propylene oxide, characterized characterized in that the starting substance is an acid-catalyzed and optionally neutralized condensation product of special alcohols having a variable degree of condensation individually or in admixture with other condensation products and solid coinitiators and / or inert and / or functional solvents or diluents and the reaction with alkylene oxides is carried out - or multi-stage, wherein the addition of the condensation products or the inert and / or functional solvents or diluents one or more times before or after the 1, or any further alkylene oxide stage. ^ 2. The method according to item 1, characterized in that the starting substance used as a condensation product based on alcohols, in which each 2 OH groups of the alcohol molecule are not connected via a chain of 4 or 5 carbon atoms, preferably butanediol (1.3) » Hexanediol (1.6), propylene glycol, glycerol or trimethylolpropane is produced. 3 "method according to item!, Characterized in that as solid coinitiators all solid or hohschmelzenden OH-functional substances, preferably 3- or 4-functional Ie alcohols such as pentaerythritol or higher functional oligosaccharides such as starch, cellulose or lignin and all solid or high-melting KH or NHg-functional and / or combined OH and KH-functional substances such as aliphatic, cycloaliphatic or aromatic amines and / or amino alcohols, in particular urea, their derivatives and reaction products or propanolamines are used »; 4 · Method according to item 1, characterized in that as inert and / or functional solvents or diluents preferably liquid alkanes such as hexane, heptane or aromatic solvents such as toluene or other solvents such as Dime thy is ulf oxide and / or 2- or 3- functional alcohols and / or 2- or polyfunctional amines or amino alcohols are used »