DD148058A1 - PROCESS FOR THE PREPARATION OF POLYETHERESTERAL COCOOLS - Google Patents

Abstract

The invention relates to a process for the economic production of polyetheresteralcohols, which are preferably suitable for the production of semi-hard and hard polyurethane foams. The aim of the invention is the preparation of polyether esters by base-catalyzed reaction of a starting substance mixture with alkylene oxide. In this case, aldehyde-group-containing monosaccharides and / or oligosaccharides and / or polysaccharides with di- or higher-functional hydroxyl-carrying coinitiators and certain amounts of di- or polycarboxylic acids are added and reacted at temperatures of 20 degrees C to 150 degrees C and under normal pressure or under vacuum, optionally further proportions of other catalytically active substances are added and optionally controlled by subsequent addition of further amounts of coinitiators and / or carboxylic acids, the reaction in a certain direction and after reaching a certain reaction stage, the reaction is completed.

Description

17922 -4-

Title of the invention

Process for the preparation of polyetheresteralcohols

Field of application of the invention

The invention relates to a process for the economical production of polyetheresteralcohols, which are preferably suitable for the production of semi-rigid and hard polyurethane foams.

Characteristic of the known technical solutions

Polyurethane foams are made by reacting polyols with aromatic polyisocyanates. The physical and mechanical properties of the polyurethane foams depend mainly on the structure of the polyols. For this purpose, especially polyethers, i. h. addition products of alkylene oxide onto hydrogen-active starter substances and / or polyesters, d. h. Reaction products of dicarboxylic acids with polyhydric alcohols used. Certain qualities are required of the feedstock to achieve certain qualities. Purely the production of rigid polyurethane foams, above all, higher-functional alcohols are used for the addition of alkylene oxide or for reaction with organic dicarboxylic acids. Cane sugar, which is suitable for the o. G. Purpose has an ideal OH-functionality. Purely the implementation of such solid starting substances with alkylene oxide or * with dicarboxylic acids for the preparation of polyether alcohols or polyester alcohols, there are a number

known solutions. In order to obtain a homogeneous starting substance which is capable of reacting with alkylene oxide, the sucrose is mixed with inert solvents such as toluene or dimethyl sulfoxide or with OH- or NH-functional solvents

The solubility of sucrose in these excipients is poor and there must be a large excess of solvent must be removed in complex, additional operations again · When water is used in the reaction with alkylene oxide different diols that reduce the average functionality of the final polyether "The esterification of sucrose with organic acids, especially fatty acids is quite complicated, since the sucrose is highly sensitive to temperature and therefore the esterification in solvents is carried out under strong catalysts or by transesterification, the disadvantage of these methods is the necessary aftertreatment of the reaction products since uncontrolled side reactions take place under esterification conditions which lead to the formation of "undesired by-products". These by-products necessitate uneconomical purification processes and influence the quality It is the negative effect of the polyurethane foams produced from the polyester alcohols.

Object of the invention

The aim of the invention is _s to develop an economical process for Her "position of Polyetheresteralkoholen based higher funk" tional Startsubstansen for use in rigid foam systems Halbhartschauaiimd *

The invention has for its object to produce polyether esters with defined adjustable composition based on higher-functional starter substances «

 - 3 * 1

According to the invention the object is achieved in that aldehygruppenhaltige monosaccharides and / or oligosaccharides, such as, for example, sucrose and / or polysaccharides, such as starch with di- or higher functional hydroxyl-carrying coinitiators and certain amounts of di- or polycarboxylic ver «sets and at temperatures of 20 ^{0 0} to 150 ⁰ C and brought under Kormaldruck or under vacuum to the reaction, where appropriate, additional proportions of catalytically active substances, Ver or transesterification catalysts, such as Lewis acids and other acids are added. As dicarboxylic acids, longer-chain aliphatic or aromatic dicarboxylic acids, such as adipic acid, are preferably used. As coinitiators are mainly low molecular weight diols, such as ethylene glycol or triols, such as glycerol or trimethylolpropane used and in a ratio of saccharide: Koinitiator from 1:10 to 10: 1, preferably 1: 5 to 5: 1 used.

The addition of the catalytically active starting substances, carboxylic acids and esterification or transesterification catalysts, such as Lewis acids and other acids can be carried out in one or in portions. In the reaction between saccharide, co-initiator and carboxylic acid, a series of reactions take place, mainly degradation reactions of oligosaccharides and polysaccharides, formation reactions of glucosides from monosaccharides and co-initiators, trans-glycosidations and esterification reactions, forming an all-round homogeneous stirrable and pumpable mixture. The amount of added carboxylic acids and the nature of the addition of the proportion of the individual reactions occurring is influenced each other and thus controlled the defined composition of the polyether alcohol, in each case a homogeneous mixture. Upon addition of an amount of carboxylic acids ί ^ λ% of the total amount of reactants used, the esterification reactions take place only to a minor extent, arise according to the addition of other acidic substances mainly glucosides or »saccharides, To increase the reaction rate of the esterification

«4 -« Y / Fi

Reactions may also be added to certain amounts of other catalytically active substances, such as specific ester and transesterification catalysts such as Lewis acids, organic and inorganic acids or titanium alcoholates. When using approximately equivalent amounts of carboxylic acids to the amount of starting substance used, different esterification reactions take place in addition to the Umglukosidierungen or _e Glukosidierurigsreaktionen and there is a homogeneous mixture with a high proportion of Ipolyethergruppierungen containing substances,

The reaction takes place at temperatures of 20 ⁰ C to 150 ⁰ C with mixing of the reactants instead. The temperature can be both set to a constant value and maintained during the reaction, or it can be varied stepwise or continuously during the reaction. The reaction proceeds either under normal pressure or under vacuum or the pressure at constant or increasing temperature during the reaction is reduced slowly, stepwise or continuously. To further control the reaction, it may be possible to prepare starting mixtures having a higher content of low-functional, low-viscosity reaction products, such as esterification products, by subsequently adding certain amounts of coinitiators. After reaching a certain reaction stage, given by the desired composition of the starting mixture and by the residual content aldehyde-saccharides, and the content is defined on Estergruppen _s, the reaction is terminated by existing reaction vacuum removed with inert gas and the temperature lowered to room temperature, is added to the homogeneous starting mixture of the necessary for the further reaction base catalyst and verührt "As basic catalysts prior to All alkali and alkaline earth metal hydroxides or amines used. »After addition to the starter substance mixtures prepared according to the invention, these basic catalysts continue to neutralize the existing NEN. acidic compounds and fix it with the. reached reaction stage · For subsequent polymerization, the starting mixture under conventional conditions such as 80 ⁰ C to 130 ⁰ C.

and 1 to 10 atü reacted in known reactors with alkylene oxides, in particular with propylene oxide and ethylene oxide. The basic polyether ester is neutralized after the alkoxylation to remove the basic catalyst with acids, acid salts or ion exchangers, freed of volatile contaminants by distillation or stripping with inert gas and the forming salts are filtered off "The inventive method has the advantage that solid or About 130 ⁰ C melting mono-, di- or oligosaccharides are converted by a suitable pretreatment in a particularly suitable for reaction with alkylene oxide starter substance mixture. Due to the homogeneity of the starter substances, which was achieved without the addition of qualitatsverschlechternden solvents, the reaction with propylene oxide and / or ethylene oxide according to the usual for the anionic polymerization of these alkylene oxides parameters, such as 100 ⁰ C to 130 ⁰ C, 0 to 10 atü and basic Catalysis in conventional circulation reactors. Another advantage is that by varying the amounts of carboxylic acid various starter mixtures which are each converted into a stirrable and pumpable form and thus polyether esters can be prepared with desired functionalities, with an adjustable ratio of ether and ester groups.

The invention will be explained in more detail below with reference to some embodiments:

Embodiment Example 1

In a 4 1 - three-necked flask equipped with stirrer, thermometer and Raschingringkolonrie, 1500 g of sucrose, 800 g of glycerol, 100 g of adipic acid and 0.5 g of H-PO ^ filled, rinsed with Hp and to a temperature of 120 ⁰ · C brought the reaction mixture for 10 h at a temperature of 120 ⁰ C and stirred for a vacuum 10-15 Torr, said accumulating distillate is constantly removed. The course of the reaction is determined by periodic examination for reducing substances.

After reaching an RV value (reduction capacity) of 4 ~ 5, the reaction is stopped by quenching the vacuum with Ng, cooling the reaction mixture and stirring in 50 g of solid KOH.

The alkaline starting substance mixture is made inert in a conventional pressure reactor with Up and reacted within 5 h at 115 ⁰ C with 5 kg of propylene oxide. "To achieve a complete conversion of Rohpolyetherester is still a further 3 h at 110 ⁰ G left in the reactor, then cooled and usually freed from the alkaline catalyst by addition of acid, distillation and subsequent filtration. "The resulting polyetherester is particularly suitable for the production of rigid polyurethane foams and has the following characteristics;

OHC a 470 mg. KOH

SZ £. 0 _f 1 mgJKOH

     G

HgO content = 0.05 % pH = 6.5

s 4900 m Pas

Ausf EADERSHIP example 2

1500 g of sucrose, 800 g of glycerol, 200 g of adipic acid and 0.5 g of titanium tetrabutoxide are filled in a laboratory apparatus consisting of flask, stirrer, thermometer, glass column and condenser with template and connection to vacuum, rinsed with Up, heated to 110 ⁰ C and h stirred under normal pressure 5 x Thereafter, the reaction is interrupted by short-time cooling, and further 200 g of adipic acid was added and heated the Reaktionsiniechung again at 110 g ^0. Thereafter, it is applied via a Zeitrqum of 2 h stepwise vacuum until a final vacuum of 15 Torr erpeicht is "The reaction is then continued for a further hour or 5 and then terminated by cooling to 60 ⁰ C and releasing the vacuum with Ug * Bs is a starting substance mixture arose which has a content of reducing saccharides of RV - 7 and an ester number of 194 S £ _K0H *

After addition of 20 g of KOH, the starter substance mixture is purged at 120 ⁰ O and pressures to 5 atü in a pressure paddle reactor with Hp and reacted with a mixture of 4 kg of propylene oxide and 2 kg of EO »The crude polyether ester is separated by addition of acid from the alkaline catalyst, by stripping and inert gas, the volatiles are removed and finally the salts formed are removed. The resulting polyetherester has the following characteristics:

OHC m 430 mg KOH

g SZ = 0.11 mg KOH

g HgO content = 0.05 %

₅ = 8500 m Pas

- 8th ·*

Claims (1)

invention claims Process for the preparation of polyether esters by base-catalyzed reaction of a starting substance mixture with alkylene oxide, characterized in that aldehyde group-containing monosaccharides and / or oligosaccharides and / or polysaccharides with di- or hö'herf unctional hydroxyl-carrying coinitiators and small amounts of di- or polycarboxylic added and at temperatures of 20 ⁰ G to 150 ⁰ C and under normal pressure or «are brought under vacuum in a reaction, where appropriate _β further An ** parts of other catalytically active substances are added and optionally" by subsequent addition of further amounts of coinitiators and / or carboxylic acids, the reaction in certain Controlled direction and after reaching a certain reaction stage, the reaction is stopped and the resulting starting material mixture with the addition of basic Ka -> catalysts at temperatures of 80 ⁰ C to 130 ⁰ C reacted with alkylene oxide and then purified _e 2 «method according to item 1, characterized in that used as oligosaccharides mainly disaccharides, preferably sucrose and co-initiators containing OH groups, such as glycerol, in a molar ratio of 1: 10 to 10: 1, preferably 1 s 5 bis'5: 1 used become" 3 · Method according to item 1, characterized in that preferably longer-chain aliphatic or aromatic dicarboxylic acids, such as adipic acid, are used as the carboxylic acids. 4e method according to item 1, characterized in that carboxylic acids are added in an amount of up to 10 % of the amount of mono-, oligo- and polysaccharide used to produce a starter substance mixture with high glucose and saccharide contents. 17922 In 5 × The method according to point 1 characterized in that the carboxylic acids used for the preparation of a starting substance mixture with a high .On ·· participate in esterification reaction in an amount of from 5% to 50% of the amounts used of mono-, oligo- or polysaccharides v / ground · 6 «method according to item 1, characterized in that as further catalytically active substances Ver or transesterification catalysts, such as Lewis acids and or other acids are added · 7 »process according to item 1, characterized in that the addition of the catalytically active substances, carboxylic acids and esterification or transesterification catalysts to the present substance mixtures takes place either in portions or all at once«