MXPA01007612A - Preparation of polyetherols. - Google Patents

Abstract

Polyetherols based on solid initiator substances and liquid, hydroxyl-containing coinitiators are prepared by a catalyzed addition reaction of alkylene oxides by a process in which the initiator combination contains ethoxy structures, the ratio of the average number of hydroxyl groups per mole of initiator combination to the number of ethoxy structures in the polyetherol being from 1:0.2 to 1:1.8 and the ratio of the amounts by weight of the ethoxy structures to the average molecular weight of the polyetherol being from 1:2 to 1:15. The polyetherols prepared by this process are used for the preparation of PUR, in particular rigid PUR foams.

Description

PREPARATION RE POLYETEROLES The present invention relates to a process for the preparation of polyetherols based on solid and liquid initiating substances, with initiators containing hydroxyl by a catalyzed addition reaction of alkylene oxides and the use of these polyetherols for the preparation of polyurethanes (PUR ), in particular rigid foams of PUR. The preparation of polyetherols by anionic polymerization has been known for a long time. Additional details in this context appear, for example in Kunststoffhandbuch, Volume VII, Polyurethane, Carl-Hanser-Verlag, Munich, l5t Edition 1066, edited by Dr.R. Vieweg and Dr. A. Höchtlen, and 2nd Edition 1983 and 3rd Edition 1993, edited by Dr. G. Oertel. The use of, for example, mono-, di- or polysaccharides and additional compounds having a high functionality in the preparation of polyetherols having a high functionality for rigid foams of PUR have been widely described. When substances having a high content of hydroxyl groups for example sucrose are used, the problem of the reaction of solid substances with alkylene oxides in a pressure autoclave occurs. In addition, the use of high temperatures during the alkoxylation reaction is limited. Thus, dark products are formed which are undesirable in numerous applications in the reaction of sucrose with alkylene oxides in the above 120 ° C. A process for the alkoxylation of solid starter substances, for example pentaerythritol, dipentaerythritol, trimethylolpropane, sorbitol, or sucrose, is described in US-A-3346557. There, the initiator substance containing from 3 to 8 OH groups per mole is mixed with an amine catalyst and alkoxylated to give an adduct consisting of a normally solid compound containing from 3 to 8 OH groups per mole, and 0.5 to 1.5 moles of vicinal alkylene oxide. For example, sucrose, tributyl amine and distilled water are mixed and propoxylated. This adduct is stripped, mixed with tributylamine and further propoxylated. The sucrose / propylene oxide adduct serves as a reaction medium to collect additional sucrose during further reaction with alkylene oxides. However, it has been found that dark products are formed through as a result of prolonged thermal stress in the course of the reaction. The introduction of sucrose into an alkoxylate and the further alkoxylation of this mixture also frequently leads to the complete conversion of the added sucrose. Free sucrose is present in the polyether that is deposited on the bottom. This effect is very highly dependent on the degree of ethoxylation and the technical equipment of the production plant. As a highlight of the amine catalysis, these polyetherols have high intrinsic reactivities that adversely accept the curing of the foams and greatly limit their use. DD-A-211797 describes a process for the preparation in the form of stages of polyetherols using solid or highly viscous initiator substances in combination with substances having a combined function, catalyst and coinitiator, for example ammonia and / or their propoxylation products . For example, aqueous ammonia solution, aqueous potassium hydroxide solution and sucrose are mixed and propoxylated in a first reaction step. The product is stripped and reacted with additional propylene oxide. The incorporation of nitrogen-containing compounds leads to reductions in viscosity with comparable functionality but also to an increase in the intrinsic reactivity of the polyetherol and consequently to a deterioration in the curing behavior. The functionality of the polyetherols is also greatly reduced by the high water content of the solutions of nitrogen-containing compounds. These polyetherols can not be used for many rigid foam applications. The required distillation step further leads to a poor yield of the raw materials used. In addition, waste water is contaminated by requiring additional technical measures.

The process described in DE-A-4209358 for the preparation of polyether alcohols based on solid and highly viscous initiator substances having hydroxyl, imino or amino functional groups comprising adding aliphatic amines in an amount of 0.5 to 5% by weight, with based on the weight of the polyol, the initiator substance or mixtures of initiator substances and then carrying out a reaction with alkylene oxides. These polyols have low potassium content and pale colors. In this process, too, the amine content of the polyol results in a higher intrinsic reactivity with respect to the isocyanates, which necessitates a decrease in the amount of foaming catalysts and consequently adversely affects the curing behavior. The processes described have not become decisively established to date. When nitrogen-containing compounds are used concomitantly, the intrinsic reactivity of the polyesterols is markedly increased in an undesirable way for many applications and thus adversely affects the curing performance of the rigid foams. The reaction of compounds having a high functionality, such as sucrose, with alkylene oxides in their own alkoxylates leads to polyesterols which have high functionality and frequently contain unconverted sucrose.

Numerous processes for the preparation of polyetherols that have a high functionality and are based on sucrose use glycerol as a coinitiator. This proven procedure leads to polyetherols that satisfy most of the property's requirements. However, they do not exhaust the possibilities of a greater effective functionality of sucrose polyetherols that have improved performance and curing and formation of a highly dense network in the foam. The process presented in US-A-5143941 for the preparation of energy absorbing PUR foams uses, inter alia, or a sucrose / dipropylene glycol / propylene oxide-based polyetherol having a hydroxyl number of about 400 mg KOH / g . In the case of this hydroxyl number, however, it is necessary to reduce the effective functionality to about 3.5, since the viscosity of the polyetherol would otherwise exceed by far 10 Pa.s, consequently the effect of a high network density and good flow behavior in the case of such polyols. CA-A-2135352 describes the preparation of rigid foams that have a good insulation effect in combination with good physical properties, good demolding ability factors and K. The formulation contains, inter alia, a polyetherol based on sucrose / propylene glycol / water and propylene oxide and a polyetherol based on sucrose / propylene glycol / water and ethylene oxide and propylene oxide. Since excessively high viscosities are generally obtained by the combination of sucrose / propylene glycol and the hydroxyl numbers for rigid foam applications and the water content reduces the functionality, the use of utility capacity is subject to limits. For the use of sucrose polyetherols having a high functionality which have advantageous processing viscosities, which give rise to an improved flow behavior or contribute towards a sufficiently high network density in the foam and are light in color, new possibilities are sought for improve the properties of the foam itself and its processing, such as curing behavior, demolding of the foams, mechanical properties, insulation behavior and heat stability and to ensure the economically advantageous use of the raw materials. It is an object of the present invention to provide rigid PUR foams having high network density and good mechanical properties, polyetherols which, with a large number of functional numbers are of relatively low viscosity, excellent properties and good thermal stability, can be reacted with polyisocyanates and conventional additives to give PUR foams. It is tried to use raw materials and economic technologies to achieve a high level of property for use in rigid industrial foams for interleaving applications, refrigerators and heating in section. It has been found that this object is achieved, according to the invention, and that it uses a combination of initiators having ethoxy structures for the preparation of the polyetherols, following the ratio of the average number of hydroxyl groups per mole of combination of initiators to the number of ethoxy structures in the polyetherol from 1: 0.2 to 1: 1.8 and the ratio of the amounts by weight of the ethoxy structures to the average molecular weight of the polyetherol being from 1: 2 to 1:15. The present invention relates to a process for the preparation of polyetherols based on solid and liquid initiating substances, or initiators containing hydroxyl by a catalyzed addition reaction of alkylene oxides, wherein the combination of initiators contains ethoxy structures, the ratio of the average number of hydroxyl groups per mole of combination of initiators to the number of ethoxy structures in the polyetherol from 1: 0.2 to 1: 1.8 and the ratio of the amounts by weight of the ethoxy structures to the average molecular weight of the polyetherol 1: 2 to 1:15. The present invention also relates to the polyetherols themselves prepared by this process and its PUR, in particular rigid foams. Rigid foams of PUR having good properties are obtained with the use of polyetherols based on sucrose-diol or diol / triol? who have ethoxy groups. It was found that the effective functionality of the polyetherols, with identical average functionality of the initiator mixtures based on the average number of functional groups per mole, is higher when the difference between the numbers of the hydroxyl groups of the substances in the mixture of initiators reaches equally or closely approximates its highest possible value. It was found, surprisingly, that the use of ethoxy structures in addition, for example, sucrose in the initiator mixture influences the properties of the polyetherol more greatly than expected. Thus, it was mainly possible to improve the curing behavior and the flow capacity substantially. An unexpectedly large effect was found in particular when the ethoxy structures are present in the initiator mixture and in the chain structure. This combination increases in particular the reduction in viscosity of the polyetherol mixture as well as substantially improving the flow behavior during foaming. According to the invention, the solid initiator substance used is essentially sucrose. However, it is also possible to use * for example, sorbitol and, if required, pentaerythritol. In the case of solid initiators, the presence of coinitiators containing liquid hydroxy is necessary to collect the solid, mix it completely and alkoxylate it. According to the invention, preferably difunctional coinitiators are used which carry ethoxy and / or their di- or tricondenses. Advantageously used coinitiators are ethylene glycols. Mono-, di- and triethylene glycol and any desired mixtures thereof are suitable. If required, water is used in addition to coinitiators. The content of solid initiators in the initiator mixture is preferably from 35 to 90, preferably particularly from 70 to 85,% by weight. In addition to the new diols bearing ethoxy, up to 10% by weight based on total weight of coinitiators used, of additional conventional coinitiators, for example propylene glycols and / or triols, such as glycerol and trimethylolpropane, may be present if appropriate. The functionality of the initiator mixture is preferably 3.5 to 6, particularly preferably 4 to 5. For the preparation of the polyxeleols, the mixture of solid and liquid initiator substances, with hydroxyl-containing initiators, is reacted with alkylene oxides . Lower alkylene oxides, advantageously ethylene oxide, propylene oxide and / or butylene oxide, they are preferably used for the alkoxylation reaction. The alkylene oxides are subjected to the addition reaction individually, in succession in blocks or in the form of random mixtures. The reaction of the initiator mixture with propylene oxide alone or the formation of a low molecular weight propoxylate, which is subsequently reacted with defined amounts of ethylene oxide, is advantageous. Then, additional propylene oxide and / or butylene oxide can be added until the desired molecular weight of the polyxeleols is reached. Further advantages of the process variants are the measurement of a mixture of alkylene oxides containing ethylene oxide and an additional addition reaction of propylene oxide or butylene oxide as the terminal block. If ethylene oxide is used, its amount is advantageously up to 30, preferably from 10 to 15%, mole percent, based in each case on the molecular weight of the polyetherol. The alkoxylation is carried out in a known manner, as explained, for example, more later. The reaction is carried out in particular at 80 to 140 ° C and 0-1 to 1.0 MPa and is catalyzed anionically or cationically, preferably with basic catalysts, such as amines or hydroxides of alkali metal or alkaline earth metal. Potassium hydroxide is particularly preferably used as a catalyst. To obtain polyetherols having the advantageous properties described above, according to the invention, a ratio of the average number of hydroxyl groups per mole of combination of initiators to the number of ethoxy structures in the polyetherol should be maintained from 1: 0.2 to 1: 1.8, preferably from 1: 0.3 to 1: 1.5, and a ratio of the weight amounts of the ethoxy structures to the average molecular weight of the polyetherol from 1: 2 to 1:15, preferably from 1: 3.5 to 1-11. If the number of ethoxy structures in the polyetherol is below these limits, the desired advantageous effects that the polyetherols have on the curing behavior and the flowability when used as components in the polyurethane system are no longer present. In the case of contents of ethoxy structures above the limits, the main OH groups are increasingly formed and the reactivity increased involuntarily. The content of the ethoxy structures results from the ethylene glycols in the initiator mixture but may be further increased by the use of ethylene oxide. The content of the ethoxy structures is also variable as a result of the possible use of condensed ethylene glycol products, the use of up to the tricondensing being convenient. After the end of the alkylene oxide addition reaction, the unpurified polyether polyol is separated from the catalyst in a known manner, for example by neutralization with an acid, distillation under reduced pressure and filtration. The polyether polyols so prepared can, if required, be additionally purified by conventional methods, for example extraction or absorption with solid sorbents extraction agents, although this is not necessary to achieve the object of the invention. The polyetherols prepared according to the invention have an OH number range of 300 to 650 mg KOH / g. Advantageous properties are shown in particular in the range of OH number from 380 to 520 mg KOH / g, so that these products are preferred for practical use. They have a functionality of 3.5 to 6. Due to the 13 .. i á High functionality feasible in the case of the new polyetherols, an important precondition for the formation of highly cross-linked rigid foams that have good mechanical stability, and due to the well-balanced behavior of flow and curing, these products are very useful for the preparation of rigid industrial PU foams. The preparation of the PUR, in particular rigid foams of PUR, is carried out in the usual way by reacting the polyetherols prepared according to the invention, and is required as a mixture with additional higher molecular weight compounds having at least two reactive hydrogen atoms, with organic, and / or modified organic polyisocyanates and, if required, low molecular weight chain extenders and / or crosslinking agents in the presence of blowing agents, catalysts, and if additional auxiliaries and / or additives are required. With respect to the initial components known per se that can be used, they can be specifically established: Suitable organic and / or modified organic polyisocyanates are the aliphatic or cycloaliphatic, araliphatic and preferably aromatic functional isocyanates known per se.

Specific examples of alkylene diisocyanates having from 4 to carbon atoms in the alkylene radical, such as 1,2-diisocyanate dodecane, 1,4-diisocyanate 2-ethyltetramethylene, 1,5-diisosianate 2-methylpentamethylene, 1, -diisocyanate tetramethylene and preferably 1,6-hexamethylene diisocyanate, cycloaliphatic diisocyanates, such as 1,3- and 1,4-cyclohexane diisocyanate and any desired mixture of these isomers, 1-isocyanato-3, 3, 5-trimethyl-5-isocyanatomethylcyclohexane ( IPDI), 2,4- and 2, β-diisocyanate hexahydrotolylene and the corresponding isomer mixtures, 4,4'-, 2,2'- and 2,4'-diisocyanate dicyclohexylmethane and the corresponding isomer mixtures, and preferably di - and aromatic polyisocyanate, for example 2,4- and 2,6-diisocyanate tolylene and the corresponding mixtures of isomers, 4,4'-, 2,4'- and 2,2'-diisocyanato diphenylmethane and the corresponding mixtures of isomers , polyphenylenepolymethylene polyisocyanates, mixtures of 4,4'-, 2,4'- and 2, 2'-diphenylmethane diisocyanates and polyphenylenepolymethylene polyisocyanate (unpurified MDI) and mixtures of unpurified MDI and tolylene diisocyanate. The organic di- and polyisocyanate can be used individually or in the form of their mixtures. Frequently, polyfunctional, modified isocyanates are also used, ie products that are obtained by chemical reaction of di- and / or organic polyisocyanates. Examples are di- and / or polyisocyanates containing ether, urea, biuret, allophanate, carbodiimide, isocyanurate, uretdione and / or urethane groups. The modified polyisocyanates can be mixed with each other or with unmodified organic polyisocyanates, for example 2,4'-diisocyanate diphenylmethane, 4, '-diisocyanate diphenylmethane, unpurified MDI, 2, tolylene-diisocyanate and / or 2,6-diisocyanate of tolylene. In addition to the novel polyether polyols described above, additional compounds having hydrogen atoms reactive towards the isocyanates can be used if required. Compounds having at least two reactive hydrogen atoms are used primarily for this purpose. Conveniently, those having a functionality of 2 to 8, preferably of 2 to 6, and a molecular weight of 300 to 8000, preferably of 300 to 3000 are used. The use depends on the desired properties of the rigid foam of PUR to the be prepared. For example, it is possible to use additional polyols selected from the group consisting of polyether polyols, polyester polyols, polythioether polyols, polyesteramide, hydroxyl-containing polyacetals and hydroxyl-containing aliphatic polycarbonates, or mixtures of at least two of the polyols. The hydroxyl number of the compounds The polyhydroxy is as a rule from 150 to 850, preferably from 200 to 600, mg of KOH / g. For example, polyether polyamines can also be used. The polyether polyols used are prepared by known processes, for example by anionic polymerization with alkali metal hydroxides, for example sodium hydroxide or potassium hydroxide, or alkali metal alcoholates, for example sodium methylate, sodium ethylate, potassium ethylate or diisopropylate of potassium, as catalysts and with the addition of at least one initiator containing from 2 to 8, preferably from 2 to 6, reactive hydrogen linked per molecule, or by cationic polymerization with Lewis acids, such as antimony pentachloride, etherate boron fluoride, etc., or bleaching soils as catalysts, of one or more alkylene oxides having from 2 to 4 carbon atoms in the alkylene radical. Other suitable polyether polyols are polyether polyols modified with polymers, preferably polyether polyols, in particular those based on styrene and / or acrylonitrile, which are prepared by in situ polymerization of acrylonitrile, styrene or preferably mixtures of styrene and acrylonitrile, for example in the ratio of weight from 90:10 to 10:90, preferably from 70:30 to 30:70, conveniently in the polyether polyols mentioned above, analogously to the data of German Patents 1111394, 1222669 (US 3304273, 3383351, 35230§3), 1152536 (GB 1040452) and 1152537 (GB 987618), and polyether polyol dispersions containing, as the dispersed phase, usually in a amount from 1 to 50, preferably from 2 to 25 weight percent, for example polyureas, polyhydrazides, polyurethanes containing tert-amino groups attached and / or melamine and which are described, for example, in EP-B-011752 (US Pat. 4304708), US-A-4374209 and DE-A-3231497. If, in addition to the new polyetherols, higher molecular weight compounds having at least two reactive hydrogen atoms are additionally used, the portion of the new polyether polyols must be at least 25% by weight. Advantageously, 30 to 70% by weight of the new polyether polyols are used based in each case on the total weight of the higher molecular weight compounds having at least two reactive hydrogen atoms. PURs, in particular rigid PUR foams, can be prepared with or without the use of chain extenders and / or crosslinking agents, although these are not generally required. The chain extenders and / or cross-linking agents used are diols and / or triols having molecular weights of less than 400, preferably from 60 to 300. For example, aliphatic, cycloaliphatic and / or araliphatic diols of 2 to 14, preferably 4 to 10, carbon atoms, for example ethylene glycol, 1,3-propanediol, 1, 10-decanediol, o-, m- and p-dibydroxycyclobexane, diethylene glycol, dipropylene glycol and preferably 1, -butanediol, 1,6-hexanediol and bis (2-hydroxyethyl) idroquinone, triols, such as 1,2,4- and 1,3,5-trihydroxycyclohexane, triethanolamine, diethanolamine, glycerol and trimethylolpropane, and oxyal-based low molecular weight hydroxyl-containing polyalkylene oxides of ethylene and / or 1,2-propylene oxide and the aforementioned diols and / or triols as starter molecules are suitable. If chain extenders, crosslinking agents or mixtures thereof are used, they are conveniently used in an amount of up to 20, preferably 1 to 10, weight percent, based in each case on the weight of the compounds having at least two reactive hydrogen atoms which are used. Blowing agents are usually used for the preparation of PUR foams. The blowing agent used in particular water, which removes carbon dioxide as a result of the reaction with the isocyanate groups. The water content is preferably from 1.1 to 4, in particular from 0.3 to 3, weight percent%, based on the weight of the compounds that are used having at least two reactive hydrogen atoms. Water can be added in combination with the use of physical blowing agents. The physical blowing agents used can be the chlorofluorocarbons (CFCs) generally known from the chemistry of polyurethanes and highly fluorinated and / or perfluorinated hydrocarbons. However, the use of these substances is greatly restricted or has been completely discontinued for ecological reasons. In addition to the chlorofluorohydrocarbons and fluorohydrocarbons, aliphatic and / or cycloaliphatic hydrocarbons are possible as alternative blowing agents. In particular, low boiling hydrocarbons, lower monofunctional alcohols and acetals, for example methylal, are used. Saturated cyclic and acyclic hydrocarbons with a low boiling point of up to 12 carbon atoms are preferred and can be used individually or as any desired mixture of one with another. In particular, pentanes are used, it being possible to use mixtures of the pentane isomers and the pure isomers. Due to the particularly low thermal conductivities, cyclopentanes are particularly preferably used. These physical blowing agents are usually added to the polyol component of the system. However, they can also be added to the isocyanate component or both to the polyol component and the isocyanate component as a combination. The amount of the physical blowing agent used or the blowing agent mixture is from 1 to 30, preferably from 5 to 20,% by weight, based in each case on the weight of component A defined below. The auxiliaries and / or additional additives are incorporated into the reaction mixture for the preparation of the PUR. Examples are catalysts and, if required, surfactants, foam stabilizers, cell regulators, fillers, dyes, pigments, flameproofing agents, hydrolysis stabilizers and fungistatic and bacteriostatic substances. For the preparation of the PUR, in particular rigid PUR foams, organic and / or modified organic polyisocyanates, the new polyether polyols and, if required, additional compounds having hydrogen atoms reactive towards the isocyanates are reacted in amounts such that the ratio of the number of equivalents of NCO groups of the polyisocyanates to the sum of the reactive hydrogen atoms of the new olieterpolyols and any additional compounds having hydrogen atoms reactive towards the isocyanates is from 0.85: 1 to 1.25: 1, preferably from 0.95: 1 to 1.15: 1, in particular from 1: 1 to 1.05: 1. If the rigid PUR foams contain at least some of the isocyanurate groups in bonded form, the ratio of NCO groups of the polyisocyanates to the sum of the reactive hydrogen atoms of 1.5: 1 to 60: 1, preferably 1.5: 1 to 8: 1, is used normally. It has proved particularly advantageous to employ the two component process and combine the components (polyether polyols prepared according to the invention, any higher molecular weight compounds having at least two reactive hydrogen atoms that are present, any low weight chain extenders molecular and / or crosslinking agents that are present, blowing agents, catalysts and any additional auxiliaries and / or additives) within a polyol component, also referred to frequently as component A and, to the use of organic and / or modified organic polyisocyanates and any blowing agent as the isocyanate component, also frequently referred to as component B. Additional information is found about the above-mentioned and additional initial materials and about the preparation of PUR in the technical literature as for example the monograph by JH Saunders and KC Frisen, "High Polymers", Voluiae XVI, Polyurethanes, Parts 1 and 2, Interscience Publishers 1962 and 1964, or the above-cited Kunststoffhandbuch, Polyurethane, Volunteer VII, Hanser-Verlag Munich, Vienna, 1st to 3rd Editions. The use of the new polyetherols in rigid foam systems leads to excellent curing and surprisingly large improvement in flowability during ! foam, with the result that the advantages of application are feasible in the industrial rigid foam, in particular in the application of section heating and cooling, but also in the case of support and design of materials in the furniture sector and in parts of construction in the automotive sector. The rigid PUR foams prepared using the new polyetherols have a density of 0.02 to 30, preferably 0.025 to 0.24, in particular 0.03 to 0.1 g / cm3. The following examples illustrate the invention but without imposing a corresponding restriction.

Example 1 (Comparison) 325 g of triethanolamine and 7 g of potassium hydroxide solution at 45% concentration were initially placed inside a 2 1 autoclave which has a stirrer, a means of measuring temperature and pressure and heating and cooling, and 320 g of sucrose were added while stirring at the same time. The mixture was then heated to 110 ° C. 1135 g of propylene oxide are measured at a reaction temperature of 110 to 115 ° C and a pressure of 4 to 6 bar. After a subsequent reaction for 2 hours at 110 ° C, the unpurified polyeterol was cooled, hydrolyzed with water, neutralized with phosphoric acid and then subjected to distillation under reduced pressure and filtered. The obtained polyetherol had the following characteristics: OH number 432 mg KOH / g Viscosity at 25 ° C 7600 mPas pH 10.0 Water content 0.04% by weight Example 2 (comparison) 135 g of ethanolamine and 9 g of 45% potassium hydroxide solution in concentration were initially placed in an autoclave according to Example lr and 320 g of sucrose was added while stirring at the same time. The mixture was then heated to 110 ° C. 1325 g of propylene oxide were then measured at a reaction temperature of 110 to 115 ° C and a pressure of 4 to 6 bar. After a subsequent reaction for 2 hours at 110 ° C, the unpurified polyeterol was cooled, hydrolyzed with water, neutralized with phosphoric acid and then subjected to distillation under reduced pressure and filtered. The polyetherol obtained had the following characteristics: OH number 437 mg KOH / g Viscosity at 25 ° C 7750 mPas pH 10.4 Water content 0.04% by weight Example 3 (comparison) 225 g of glycerol and 9 g of potassium hydroxide solution at 45% in concentration, an autoclave was initially placed in the form of Example 1, and 360 g of sucrose was added while stirring at the same time. The mixture was then heated to 110 ° C. 1215 g of propylene oxide were then measured at a reaction temperature of 110 to 115 ° C and a pressure of 3 to 6 bar. After a subsequent reaction for 2 hours at 110 ° C, the unpurified polyeterol was cooled, hydrolyzed with water, neutralized with phosphoric acid and then subjected to distillation under reduced pressure and filtered. The polyetherol obtained had the following characteristics: OH number 493 g KOH / g Viscosity at 25 ° C 8490 mPas pH 8.3 Water content 0.02% by weight Example 4 (according to the invention) 180 g of diethylene glycol and 9 g of 45% potassium hydroxide solution in concentration were initially introduced into an autoclave in the form of Example 1, and 480 g of sucrose was added while stirring at the same time. The mixture was then heated to 110 ° C. 1125 g of propylene oxide were then measured at a reaction temperature of 110 to 115 ° C and a pressure of 4 6 bars. After a subsequent reaction for 2 hours at 110 ° C, the unpurified polyeterol was cooled, hydrolyzed with water, neutralized with phosphoric acid and then subjected to distillation under reduced pressure and filtered. The polyetherol obtained had a ratio of average number of hydroxyl groups per mole of combination of initiators to the number of ethoxy structures in the polyetherol of 1: 0.5 and a composition of the amounts by weight of the ethoxy structures relative to the average molecular weight of the polyetherol of 1: 6.8. The following characteristics were determined: OH number 435 mg KOH / g Viscosity at 25 ° C 5660 mPas pH 8.6 Water content 0.071% by weight Example 5 (according to the invention) 180 g of diethylene glycol and 9.5 g of 45% potassium hydroxide solution in concentration were initially placed in an autoclave according to Example 1, and 480 g of sucrose was added while stirring at the same time. The mixture was then heated to 110 ° C. 270 g of ethylene oxide were then added at a reaction temperature of 105 to 110 ° C and a pressure of 4 to 5 bar. After a subsequent reaction time of 1 hour at 110 ° C, 830 g of propylene oxide were measured at a reaction temperature of 110 to 115 ° C and a pressure of 3 to 6 bar. After a subsequent reaction for 2 hours at 110 ° C, the un-purified polyetherol was cooled, hydrolyzed with water, neutralized with phosphoric acid and then subjected to distillation under reduced pressure and filtered. The polyetherol obtained had a proportion of the average number of hydroxyl groups per mole of combination of initiators with respect to the number of ethoxy structures in the polyetherol of 1: 1.4 and a proportion of the amounts by weight of the ethoxy structures with respect to the average molecular weight of polyetherol of 1: 2. The following characteristics were determined: OH number 402 mg KOH / g Viscosity at 25 ° C 2050 mPas PH 8.02 Water content 0.03% by weight Example 6 (according to the invention) 127 g of monoethylene glycol and 9 g of 45% potassium hydroxide solution in concentration were initially introduced into an autoclave in the form of Example 1, and 480 g of sucrose was added while stirring at the same time. The mixture was then heated to 110 ° C. 1175 g of propylene oxide were then measured at a reaction temperature of 110 to 115 ° C and a pressure of 3 to 6 bar. After a subsequent reaction for 2 hours at 110 ° C, the unpurified polyeterol was cooled, hydrolyzed with water, neutralized with phosphoric acid and then subjected to distillation under reduced pressure and filtered. The polyetherol obtained had a ratio of the average number of hydroxyl groups per mole of combination of initiators with respect to the number of ethoxy structures in the polyetherol of 1: 1.5 and a proportion of the amounts by weight of the ethoxy structures with respect to the average molecular weight of polyetherol of 1: 5.6. The following characteristics were determined: OH number 491 mg KOH / g Viscosity at 25 ° C 12080 mPas pH 7.85 Water content 0.03% by weight Example 7 (according to the invention) 307 g of triethylene glycol and 8 g of 45% strength potassium hydroxide solution were initially introduced into an autoclave in the form of Example 1, and 500 g of sucrose were added while stirring at the same time. The mixture was then heated to 110 ° C. 1000 g of propylene oxide were then measured at a reaction temperature of 110 to 115 ° C and a pressure of 3 to 6 bar. After a subsequent reaction for 2 hours at 110 ° C, the unpurified polyeterol was cooled, hydrolyzed with water, neutralized with phosphoric acid and then subjected to distillation under reduced pressure and filtered. The obtained polyetherol had a ratio of the average number of hydroxyl groups per mole of combination of initiators with respect to the number of ethoxy structures in the polyetherol of 1: 0.9 and a proportion of the amounts by weight of the ethoxy structures with respect to the average molecular weight of polyetherol of 1: 4. The following characteristics were determined: OH number 481 mg KOH / g Viscosity at 25 ° C 9570 mPas pH 9.71 Water content 0.03% by weight Example 8 (according to the invention) 190 g of diethylene glycol and 8.5 g of potassium hydroxide solution at 45% concentration were initially placed in an autoclave in the form of Example 1, and 440 g of sucrose were added while stirring at the same time. . The mixture was then heated to 110 ° C. Then 450 g of propylene oxide were added at a reaction temperature of 110 to 115 ° C and a pressure of 3 to 6 bar. After a subsequent reaction for 2 hours at 110 ° C, this prepolymer having the following characteristics: Viscosity at 75 ° C about 1000 mPas Total alkalinity about 0.34% KOH Reacted with an additional 690 g of propylene oxide. The unpurified polyetherol was cooled, and hydrolyzed with water, neutralized with phosphoric acid and subjected to a distillation under reduced pressure and filtered. The polyetherol obtained had a ratio of the average number of hydroxyl groups per mole of initiator combination with respect to the number of ethoxy structures in the polyetherol of 1: 0.8 and a proportion of the amounts by weight of the ethoxy structures with respect to the average molecular weight of polyetherol of 1: 3.6. The following characteristics were determined: OH number 442 mg KOH / g Viscosity at 25 ° C 6520 mPas pH 7.96 Water content 0.01% by weight (The prepolymer was able to be stored and could be used as an initial material for the additional final synthesis in the main reactor).

Example 9 (according to the invention) 176 g of diethylene glycol and 10 g of 45% potassium hydroxide solution in concentration were initially placed in an autoclave in the form of Example 1, and 406 g of sucrose were added while stirring at the same time. The mixture was then heated to 110 ° C. 230 g of ethylene oxide and 450 g of propylene oxide, as a mixture, were then measured at a reaction temperature of 110 to 115 ° C and a pressure of 3 to 6 bar. After a subsequent reaction for one hour at 115 ° C, an additional 530 g of propylene oxide was added. After a subsequent reaction for 2 hours at 110 ° C, the unpurified polyeterol was cooled, hydrolyzed with water, neutralized with phosphoric acid and then subjected to distillation under reduced pressure and filtered. The polyetherol obtained had a ratio of the average number of hydroxyl group per mole of combination of initiators with respect to the number of ethoxy structures in the polyetherol of 1: 1.6 and a proportion of the amounts by weight of the ethoxy structures with respect to the average molecular weight of polyetherol of 1: 2. The following characteristics were determined: OH number 404 mg KOH / g Viscosity at 25 ° C 2280 mPas PH 8.95 Water content 0.02% by weight Example 10 (comparison) A polyol component consisting of 54 parts by mass (pbm) of a polyeterol according to Example 1, having an OH number of 432 mg KOH / g, 4.2 pbm of glycerol, 21.1 pbm of a polyetherol based on a monoethylene glycol and propylene oxide, OH number of 105 mg KOH / g , 1 pbm of silicone stabilizer B 8409 (from Goldschmidt), 1.8 pbm of dimethylcyclohexylamine, 2.4 pbm of water and 15.5 pbm of R 141 b, was mixed thoroughly with 125 pbm of unpurified MDI, NCO content at 31.5 mass% ( feature 110). When subjected to free foam lifting in foam beaker, the resulting foam had a density of 29.2 kg / m3 Example 11 (comparison) A polyol component according to Example 10, but containing 54 parts by mass (pbm) of a polyetherol according to Example 2, having an OH number of 437 mg KOH / g (instead of the polyetherol according to Example 1), was mixed thoroughly with 125 pbm of MDI, without purification, NCO content of 31.5% by mass (characteristic 110). The resulting foam had a density of 30.0 kg / m3.

Example 12 (comparison) A polyol component according to Example 10, but containing 54 parts by mass (pbm) of a polyetherol according to Example 3, having an OH number of 493 mg KOH / g (instead of the polyetherol according to Example 1), was mixed thoroughly with 125 pbm of MDI, without purification, NCO content of 31.5% by mass (characteristic 110). The resulting foam had a density of 30.5 kg / m3.

Example 13 (according to the invention) A polyol component according to Example 10, but containing 54 parts by mass (pbm) of a polyetherol according to Example 4, having an OH number of 435 mg KOH / g (instead of of the polyether according to Example 1), was mixed thoroughly with 125 pbm of MDI, without purification, NCO content of 31.5% by mass (characteristic 110). The resulting foam had a density of 31.0 kg / m3.

Example 14 (according to the invention) A polyol component according to Example 10, but containing 54 parts by mass (pbm) of a polyetherol according to Example 5, having an OH number of 422 mg KOH / g (instead of the polyether according to Example 1), was mixed thoroughly with 125 pbm of unpurified MDI, NCO content of 31.5% by mass (characteristic 110). The resulting foam had a density of 30.2 kg / m3.

Example 15 (according to the invention) A polyol component according to Example 10, but containing 54 parts by mass (pbm) of a polyetherol according to Example 6, having an OH number of 491 mg KOH / g (instead of of the polyether according to Example 1), was mixed thoroughly with 125 pbm of unpurified MDI, NCO content of 31.5% by mass (characteristic 110). The resulting foam had a density of 31.5 kg / m3.

Example 16 (according to the invention) A polyol component according to Example 10, but containing 54 parts by mass (pbm) of a polyetherol according to Example 7, having an OH number of 481 mg KOH / g (instead of the polyether according to Example 1), was mixed thoroughly with 125 pbm of unpurified MDI, NCO content of 31.5% by mass (characteristic 110). The resulting foam had a density of 31.0 kg / m3.

Example 17 (according to the invention) A polyol component according to Example 10, but containing 54 parts by mass (pbm) of a polyetherol according to Example 8, having an OH number of 442 mg KOH / g (instead of of the polyether according to Example 1), was mixed thoroughly with 125 pbm of MDI, without purification, NCO content of 31.5% by mass (characteristic 110). The resulting foam had a density of 30.0 kg / m3.

Example 18 (comparison) A polyol component according to Example 10, but containing 54 parts by mass (pbm) of a polyetherol according to Example 9, having an OH number of 404 mg KOH / g (instead of the compliant polyetherol to Example 1), was mixed thoroughly with 125 pbm of MDI, without purification, NCO content of 31.5% by mass (characteristic 110). The resulting foam had a density of 29.5 kg / m3. The foams obtained were investigated by means of the screw test with respect to their curing and by means of the tube test with respect to their flowability. Screw test Using a standardized 20 mm diameter screw, the penetration force within the foam is measured at specific time intervals after preparation. The screw penetrates 10 mm into the foam.

Tube Test Immediately after mixing the components, 100 g of reaction mixture is poured into a continuous tube comprising a plastic film having a diameter of 4.5 cm. The tube is then clamped and the length of the foam achieved is taken as a measure of the flowability. The results obtained are shown in Table 1.

Table 1 tttitcttn ittii iYAJ The new rigid polyurethane foams based on novel polyols presented better curing and better flow behavior compared to those based on comparative polyols.

Claims (8)

1. A process for the preparation of polyetherols based on solid and liquid initiator substances, hydroxyl-containing coinitiators by a catalyzed addition reaction of alkylene oxides, wherein the combination of initiators contains ethoxy structures, the ratio of the average number of hydroxyl groups per mole of combination of initiators with respect to the number of ethoxy structures in the polyetherol being from 1: 0.2 to 1: 1.8 and the proportion of the weight amounts of the ethoxy structures relative to the average molecular weight of the polyetherol being from 1: 2 to 1 :fifteen.

2. The process as claimed in claim 1, wherein difunctional coinitiators are used that carry ethoxy structures and, if water is required.

3. The process as claimed in claim 1 or 2, wherein the coinitiators used are diols and / or are di- or tricondensed.

4. The process as claimed in any of claims 1 to 3, wherein the coinitiator used is ethylene glycol.

5. The process as claimed in any one of claims 1 to 4, wherein it contains sucrose in the initiator mixture is from 35 to 90% by weight.

6. The process as claimed in any of claims 1 to 5, wherein, the functionality of the primers are mixed in 3.5 to 6. The preparable polyetherol as claimed in any of claims 1 to 6, which has a number of hydroxyl of 300 to 650 mg KOH / g. 8. The use of a polyetherol as claimed in claim 7, for the preparation of polyurethanes, in particular rigid polyurethane foams.