DE19648724A1 - Lignin containing poly:hydroxy compound used to give polyurethane - Google Patents

Abstract

Lignin containing polyhydroxy compounds are claimed which are prepared by reacting a solution, comprising lignin of salt content, based on Na and K ions, of 5000-15000 ppm, a polyalkylene glycol(s) from polyethylene glycols and/or polypropylene glycols giving a total OH functionality of at least 2 and optionally an OH, NH or NH2 functional compound(s) of H functionality at least 2, with an alkylene oxide(s). Also claimed are the preparation of the above compounds, the preparation of compact or flexible polyurethanes by reacting high mol wt. compounds with at least two reactive H atoms, preferably polyhydroxy compounds, and lignin containing polyhydroxy compounds with optionally modified organic polyisocyanates, optionally in the presence of chain extenders and/or crosslinkers, propellants, catalysts and aids and the obtained compact or cellular polyurethanes. Preferably the polyalkylene glycols have a mol. wt. of 400-4000, preferably 600-1500 and a polypropylene glycol content of 0-50, especially 0-10%. The lignin has a salt content of 5000-12000 ppm. The functional compound is an at least diol, sugar alcohol, saccharide, amino alcohol or aliphatic or aromatic amine. The high mol wt. compounds have a functionality of 2-8 and an OH number of 25-500, preferably from polythioether polyols, polyester amides, OH containing polyacetals and polycarbonates, polyester polyols, polyether polyols and/or polymer-modified polyether polyols. The propellant is water and/or 3-7C alkanes.

Description

The present invention relates to lignin-containing polyhydroxyl links. The invention also relates to methods of manufacture such lignin-containing polyhydroxyl compounds. After all, is the subject the invention also the use of the lignin-containing polyhydroxylver Bonds according to the invention for the production of polyurethanes, ins special of foamed moldings based on polyurethane, and Ver drive for this.

The production of polyurethanes by reacting diisocyanates with bifunctional or polyfunctional polyols have long been known and have been described many times. This includes the use of lignin-containing Polyols for the production of rigid, semi-hard or elastic poly urethane (PUR) foams known.

Lignins are a by-product of wood pulp production instruct and are mostly under energy and chemical return extraction burned. Lignin, which is obtained for technical use and is isolated, almost exclusively becomes lignosulfonates processed. Pure lignin is only used to a small extent technically.  

Lignin can be isolated using various methods, the extraction method having a major influence especially on the molecular weight of the crosslinked polyaromatic lignin (1000 to 6000). Organosolvlignins have a low molecular weight as Kraft lignins, functionality and breadth of the molecular weight distribution are comparable. The fractionation of Kraft lignin gives <50% with M _n <2000 and M _w / M _n <2 and <40% with M _n <3800 and M _w / M _n = 20 to 30. About number and type (aliphatic or phenolic) of the hydroxyl groups is mainly determined by the type of wood processed (hard or soft wood). An average of 1.3 OH groups per "C9 basic unit" of lignin with a molecular weight of 186 can be assumed, in each case approximately half aliphatic and phenolic OH groups. Lignin serves to strengthen and stabilize in nature (also against biodegradation) and has good thermal stability with T _g approx. 180 ° C.

Poly produced with lignin and tannin as starter molecules are known oxyalkylene polyols. According to US-A-3,546,199 and US-A-3,654,194 can lignin or tannin in the presence or absence of solution means with alkylene oxides, such as. B. 1,2-propylene oxide, at temperatures alkoxylated from 20 to 250 ° C and optionally increased pressure. The polyoxyalkylene polyols produced have hydroxyl numbers in the range from 50 to 1000, preferably from 200 to 800, and are suitable Reaction with organic polyisocyanates for the production of flexible to hard PUR foams.

EP-A-0 342 781 describes the use of lignin in the PUR-Her position. Solutions of lignin in tetrahydrofuran (THF) or polyoxy ethylene glycol (PEG) with diphenylmethane diisocyanate (MDI) at 60 ° C or reacted at room temperature. The ones obtained from it Films have good mechanical strength, foams have good elasticity  act according to the information in the publication. There will be no comparison games listed without lignin. The lignin forms the hard phase, the PEG the Soft phase.

Lignin can also be dissolved in and from polyoxyethylene glycols (PEG) Solution be implemented with isocyanates to polyurethane parts, such as it is described in US-A-3,519,581. The lignin is used in one Polyoxyethylene glycol (PEG) or a mixture of PEG and Polyoxypro pylene-glycol (PPG) dissolved and if necessary at temperatures above 100 ° C treated for the esterification of the carboxyl groups of the lignin. The received Lignin-polyoxyalkylene-glycol solutions are advantageously applied to one Let the temperature cool below 100 ° C before using the Polyisocya be reacted to form polyurethanes. The Reaction always takes place in the presence of a surface-active compound instead of.

US-A-3,577,358 describes the lignin for reaction either in PEG or to dissolve in dioxane. The curing takes place during several Hours at room temperature or at an elevated temperature (<80 ° C). Polyurethane insulation is done by removing the solvent. lignin and isocyanate react when mixed at 120 ° C. The IR Spectrum shows that all OH and -N = C = O groups have reacted.

However, the direct use of lignin in polyurethane systems is available in addition to the lack of reactivity of the solid but also dissolved lignin, e.g. B. Lignin dissolved in tetrahydrofuran or dioxane, compared to isocyanates under the conditions of polyurethane production still a number of other disadvantages in the way. Their high salt content affects the sensitive che catalysis of the PUR systems very strong, especially when the lignins be used as a solution and not as a solid. Lignins are indu  Striell mainly used as a "thickener", correspondingly increasing viscosity in higher concentrations they also affect water-containing poly etherol components. There is also often an intolerance to the lignin with other PUR polyol components, which has the consequence that the very fine lignin particles after the poly coalesce ole-chemical so that it can no longer be processed. From the reasons listed could lignin polyurethanes in their processing and also do not satisfy product properties. Generally, through Installation of the lignin itself in polyurethane foams the mechanical properties shaft deteriorated. To make PUR parts with good properties at all , specially fractionated lignins are often used or lignins, which were obtained using a special process (e.g. Orga nosolvlignine).

The usual disadvantages of lignin in the production of PUR are the lack of reactions vity, lack of incorporation of the lignin in the PUR matrix. Are lignin solutions usually highly viscous and poor with organic polyisocyanates miscible; in addition, the foams have poor mechanical properties create. The high molecular weight portions of the lignin are separated and the reaction is carried out in solution, you get PUR parts for which one A number of advantages are reported. E.g. a lower index is needed tigt, cf. CA-A-2,052,487. With Kraft lignin itself, the PUR Polyaddi can tion reaction in a PEG solution. The molecule Larign weight of the lignin and the viscosity of the lignin solution in PEG are too high, the miscibility with the isocyanate component is too poor. With special modified lignin, e.g. B. such with a low molecule Lar weight from 300 to 2000 and better solubility, become more homogeneous Obtain foams with good mechanical properties. It can be a one shot or a prepolymer procedure can be used. In the latter In this case, a prepolymer is made from lignin / polyols / isocyanates  then cast into films or by mixing with water / Kataly sators / stabilizers can also be foamed.

To those listed associated with the direct processing of the lignin The oxalkylation of lignin will also overcome difficulties suggested. However, this is expensive. Generally find lignins or Lignin derivatives due to the (processing) difficulties listed currently no use on an industrial scale for the production of polyurethanes.

WO-A-86/07070 describes a process for the production of polyurethanes by polymerizing polyisocyanates, polyol and kraft lignin or another type of technical lignin, the reactivity and the Properties of the lignin can be improved in that the high molecular weight Ren portions of the lignin are separated and the reaction between Isocyanate and lignin is carried out in solution. DE-A-42 26 327 open bears binders based on furan resins and lignin for manufacture of curable molding compounds, high temperature resistant molding materials and refractory products, in particular foundry cores and molds. The Binders contain a furan resin and 5 to 50 wt .-% lignin from the Organosolv process, as well as organic and / or inorganic acids Harder.

Lignin has been used in the past as a solid, in reactive or unreactive ven solvents, in water or in suspension in toluene and as hydroxypropyllignin (HPL) or chain-extended HPL (CEHPL) Precipitation isolated. Both Kraft lignins and lignosulfonates have been oxyalkylated. In several publications (W.G. Glasser et al., In: Ency clopedia of Polymer Science & Engineering, Wiley, 1987, Vol. 8, 795-852, "Lignin"; W.G. Glasser et al., ACS Symposium Series 397, ACS, 1989, "Lignin - Properties and Materials") become synthesis and the implementations  described the HPL to polyurethanes, usually in the form of PUR Films that were poured out of a THF solution. The implementation Lignin with alkylene oxides in aqueous solution leads to products with a very high molar excess of polyoxyalkylene diols, so that the product mix is very limited for the production of polyurethane suitable. Isolation of the lignin alkoxylates as HPL or CEHPL on the other hand is complex and large-scale for the production of polyu basic rethane products not feasible. Alkoxylated lignins can then in Contrary to lignins, which still contain free phenolic OH groups also bleached to give the very dark color of the lignins remove. Hydroxy propyl lignins are also used to make prepolymers suitable. Because of complex production, poor processability, unbe peaceful product properties and poor tolerance of lignin-hal term polyols with other polyurethane components become lignin-containing Polyols currently not on an industrial scale for the production of polyu Rethane shares used.

US-A-3,476,795 describes hydroxy esters of phenolic acids from Tree bark described from the implementation of sodium salts phenolic acid from tree bark with an alkylene oxide, such as. B. Ethylene oxide, propylene oxide can be obtained. These hydroxy esters can be further processed with polyurethanes to react with isocyanates. The patent does not mention lignin.

US-A-3,672,817 describes a lignosulfonate adduct as a dispersant, that reduces the particle size of the dye in dye compositions. The lignosulfonate adduct is hydroxyalkylated and is reacted of lignosulfonate with z. B. alkylene oxide formed. US-A-4,184,845 a two-step process for lightening sulfonated alkali metal lignins and lignosulfonates. In the first stage of the process, at least  90% of the phenolic OH groups of the lignin by reaction with a Blocking agents, e.g. As propylene oxide, blocked, and then that blocked lignin oxidized with air, oxygen or hydrogen peroxide. Of the Blocking step is done by simply dissolving the lignin in water and Mixing with the blocking agent, if appropriate in the presence of a catalyst, such as B. sodium hydroxide. The disadvantage here is that the alkoxylation in Water leads to compounds of little use in polyurethane.

US-A-4,918,167 relates to a process for the preparation of prepolymers from Hydroxyalkyl lignin. Lignin is used to produce the hydroxyalkyl lignin 1,2-oxides, e.g. B. propylene oxide, in the presence or absence of a catalyst sators implemented, with this patent all phenolic OH groups be saturated. The hydroxyalkylation of the lignin is carried out the poor solubility of the lignin and other adverse effects overcome mechanical properties of solid polymers, however they are complex and technically impractical.

US-A-3,546,199 and US-A-3,654,194 describe how solid, powdery or lignin dissolved in reactive or unreactive solvents catalyst-free and with KOH-aniline catalysis to lignin polyetherols can be set. From the OH numbers of the polyols obtained, the Back calculated OH numbers of the lignins. They are approximately 600 to 1300. Tannin can be used as well as lignin. The OH numbers of the lignin Polyether polyols are 50 to 1000. In the case of using one Catalyst such. B. alkali or alkaline earth metal hydroxides, it is proposed the resulting inorganic salts from the polyol product remove what happens that the polyol formed in a liquid Solvents such as methanol or ethanol are dissolved, the inorganic Salts are precipitated, the polyol solution is filtered and finally the resulting polyol solution is treated with ion exchange resins. US-A-3,546,199  and US-A-3,654,194 say nothing about the purity of the used lignins.

The object of the present invention was to process new ones well To provide bare lignin-containing polyhydroxyl compounds. Another The object of the invention was to provide such lignin-containing polyhydroxyl Specify connections in their further processing to polyurethane products, especially for polyurethane foams, result in products that improved processing properties such as faster curing with ver better flow behavior and more uniform density distribution with a short Setting time and improved physical properties, especially what In terms of heat resistance and thermal conductivity. A Another object of the present invention was to create Process for the preparation of such lignin-containing polyhydroxyl compounds and of processes for the production of polyurethanes with the improved Characteristics.

This problem is solved by lignin-containing polyhydroxyl compounds, as defined in the claims. The method according to the invention for the production of such lignin-containing polyhydroxyl compounds and the Use for the production of polyurethanes and polyurethane products and methods therefor are also defined in the claims. Preferred Embodiments of the invention result from the following description exercise and the subclaims.

According to the invention, a natural substance, namely lignin, is advantageously used used as a renewable polyhydroxyl compound.

Surprisingly, it was found that lignin-containing solutions obtained from lignins with a high salt content and polyalkylene glycols, in particular from lignin at least partially esterified with polyethylene glycols, with alkylene oxides, optionally in the presence of OH, NH or NH ₂ -functional compounds as Coinitiators can be implemented and that this oxyalkylation leads to homogeneous, low-viscosity, stable, with other components well compatible products. In particular, it was found that the oxyalkylation also takes place when no catalysts are added. As a result of the presence of lignin (and thus the ingredients present in the lignin), the oxyalkylation is catalyzed so selectively that lignin-containing polyhydroxyl compounds can be produced in a very wide molecular weight range, which leads to the production of hard and soft polyurethane foams which cure quickly, with improved performance Flow of the systems are particularly suitable.

The natural product lignin, e.g. B. the commercially available Kraft lignin indulin AT from Westvaco or the sodium lignin sulfonate 220 Zewa EF from Lignotech, contains residual salt contents as the residue of the lignin production of usually <1000 ppm, in particular <5000 ppm, measured as Na and K ion content. In general, the residual salt content of the lignin depends on the wood used and the manufacturing technology. According to the invention becomes lignin with a high salt content, preferably with a salt content between 5000 and 15,000 ppm.

The lignin-containing polyhydroxyl compounds provided according to the invention result from the reaction

• b1) a solution that contains
• b11) Lignin with a salt content, measured as Na and K ions content, between 5000 and 15 000 ppm and
• b12) at least one polyoxyalkylene glycol selected from polyox ypropylene glycols, polyoxypropylene polyoxyethylene glycols and mixtures thereof, and mixtures thereof with Polyhy  droxyl compounds with an OH functionality of ≧ 2, and possibly.
• b13)) at least one OH, NH and / or NH ₂ -functional compound with an H functionality of ≧ 2, with
• b2) at least one alkylene oxide.

The lignin-containing solution b1) preferably contains 5 to 99% by weight, in particular 15 to 85 wt .-%, preferably 30 to 70 wt .-% polyoxyalky lenglycol b12) and optionally 0 to 94% by weight, in particular 0 to 60% by weight, preferably 0 to 40% by weight of compound b13), while the amount of lignin is 1 up to 95% by weight, in particular 15 to 85% by weight, especially 30 to 70 % By weight that makes up the solution. According to the invention, this is preferred Ratio of lignin-containing solution b1) to the at least one alkylene oxide b2) 1 to 95 wt .-% solution b1) and 5 to 99 wt .-% b2), ins special 1 to 85% by weight of solution b1) and 15 to 99% by weight of alkylene oxides b2), preferably 1 to 70% by weight of solution b1) and 30 to 99% by weight Alkylene oxides b2).

According to the invention, a lignin with a Salinity, measured as Na and K ion content, between 5000 and 15,000 ppm, preferably between 5000 and 12,000 ppm, in particular between 5000 and 10,000 ppm. Lignin suitable according to the invention are commercially available usual Kraft lignin such as the Indulin AT from Westvaco, Charleston, SC, USA, or lignin isolated by any other method.

It is also possible to use hydroxyalkyllignins, e.g. B. hydroxypropyllignine, as Component b11) to use.

Suitable polyoxyalkylene glycols b12) are polyoxypropylene-polyoxyethylene glycols, especially those with a molecular weight of 400 to 4000,  preferably from 600 to 1500. Their polypropylene oxide content is preferably 0 to 50%, in particular 0 to 20% and preferably 0 to 10%.

Further suitable polyoxyalkylene glycols b12) selected from polyoxypropy len- and polyoxypropylene-polyoxyethylene glycols, preferably have one Functionality from 2 to 8 and hydroxyl numbers from 25 to 500, where for flexible PUR foams polyoxyalkylene glycols with one functionality from 2 to 3 and a hydroxyl number from 30 to 80 and for semi-hard and hard PUR foams polyoxyalkylene glycols with a functionality of 3 to 8 and a hydroxyl number of 100 to 500 are preferably used and suitable polyoxytetramethylene glycols have a hydroxyl number of 30 have up to about 280.

In a preferred embodiment of the invention, the lignins in Polyethylene glycols as component b12) dissolved and under alkaline Catalysis anhydrous oxyalkylated. The solubility of the lignins increases increasing molecular weight and is in PEG 600 <40%, in PEG 1500 <30% and in PEG 4000 <20%. Compared to oxyalkylation There are clear advantages of aqueous lignin solutions with an oxal kylation in polyethylene glycols. So is the proportion of difunctional Low polyetherols, the lignin alkoxylate-containing polyol mixture is directly for Production of polyurethane parts usable and a complex and It is not technically feasible to isolate hydroxyalkyl lignins necessary. It can be clearly demonstrated using chromatographic methods that under the conditions of the present invention, the lignin itself and even preferred over the polyethylene glycol, which here as Coinitiator b13) and solvent b12) acts, is alkylated. Here a high molecular weight lignin alkoxylate is formed. Polyetherols high molecular weights are usually only more specific Complex catalysts (cyanide complexes of double metals) and under high  Costs producible. Another advantage is that the invention lignin-containing polyols in the usual workup steps are easier to clean than known lignin-containing polyols. Doing so the reaction conditions are chosen so that poly is not preferred ether diols are formed.

In a preferred embodiment of the invention, OH, NH and / or NH ₂ -functional compounds b13) are incorporated as coinitiators of solution b1). Suitable coinitiators b13) are OH, NH and / or NH ₂ -functional compounds with a functionality of 2 to 8, advantageously two and / or higher functional alcohols, sugar alcohols and / or saccharides, in particular ethylene or propylene glycol, Glycerin, sorbitol and / or sucrose. In addition, aliphatic and / or aromatic amines or amino alcohols, in particular ethylenediamine, tolylene diamine and / or alkanolamines such as ethanolamines or propanolamines, are also suitable.

Suitable alkylene oxides b2) are, for example, ethylene oxide, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide and tetrahydrofuran. Preferably 1,2-propylene oxide used. Especially at the beginning of the alkoxylation reaction tion are more substituted alkylene oxides with at least 3 carbon atoms, such as e.g. B. propylene oxide, butylene oxide, styrene oxide used. Most before is propylene oxide. It is less preferred to use the highly reactive ethylene oxide, as this is preferred with the reactive primary OH groups of the polyoxyalkylene glycol reacted less with OH groups pen of the lignin. The alkylene oxides b2) used are preferably more than 50% more substituted alkylene oxides, especially propylene oxide.

In the process according to the invention for producing the lignin-containing Polyhydroxyl compound, the above-mentioned components lignin,  at least one polyoxyalkylene glycol and at least one alkylene oxide under Formation of the lignin-containing polyhydroxyl compound reacted with one another.

Are preferred when carrying out the method according to the invention for the preparation of the lignin-containing polyhydroxyl compounds at the beginning of Alkoxylation reaction as long as only higher substituted alkylene oxides, in particular propylene oxide, reacted with solution b1) until at least 50% of the total amount of alkylene oxide used are implemented. Preferential solution b1) is wise before the reaction with the alkylene oxides b2) at a temperature of 80 to 130 ° C, preferably under pressure by Max. 30 mbar over a period of 1 to 8 hours. The reaction of solution b1) with the alkylene oxides b2) is described in Ab presence or in the presence of acidic or basic catalysts, e.g. As potassium hydroxide, sodium hydroxide or Lewis acids performed. There the oxalkylation reaction also takes place in the absence of catalysts, is preferably carried out without the addition of catalysts.

When carrying out the alkoxylation reaction, it is advantageous to use water to remove from the reaction mixture in the course of the reaction. In particular other water, but also from it in the course of the alkoxylation reaction Low-molecular glycols formed interact with lignin to a significant increase in the viscosity of the lignin-containing polyhydroxy yl compounds. In the course of this drainage, there is also a at least partial esterification of the lignin carboxyl groups with the Solvent and the polyalkylene glycol.

The invention further relates to a process for the production of compact or flexible polyurethanes, preferably PUR foams, by reacting

• a) High molecular weight compounds with at least two reactive water atoms of matter, preferably polyhydroxyl compounds, and
• b) Lignin-containing polyhydroxyl compounds
• c) organic polyisocyanates and / or modified organic polyiso cyanates,
  in the presence or absence of
• d) chain extenders and / or crosslinking agents,
• e) blowing agents,
• f) catalysts and
• g) auxiliaries.

According to the invention, there is the lignin-containing polyhydroxyl compound b) from a lignin-containing polyhydroxyl compound as defined above has been.

In the process according to the invention for the production of Polyurethanes that the higher molecular weight compounds a) functionality from 2 to 8 and an amine or hydroxyl number from 25 to 500 and are expediently selected from the group of polyoxyalkylene polyamines and / or the polyhydroxyl compounds, especially the polyhy droxyl compounds with a functionality of 2 to 8 and a hydrox yl number from 25 to 500, which in turn are preferably selected from the Group of polythioether polyols, polyesteramides, hydroxyl-containing Polyacetal, hydroxyl-containing aliphatic polycarbonates, polyester polyols, polyether polyols, polymer-modified polyether polyols, preferred as polyether polyols and mixtures of at least two of the above Polyhydroxyl compounds.

Suitable higher molecular weight polyhydroxyl compounds, as ver in a) have, as has already been stated, expediently  a functionality of 2 to 8 and a hydroxyl number of 25 to 500, poly is preferred for the production of flexible PUR foams hydroxyl compounds with a functionality of preferably 2 to 3 and a hydroxyl number of preferably 30 to 80 and for the preparation of hard PUR foams prefer polyhydroxyl compounds with a Functionality of preferably 3 to 8 and in particular 3 to 6 and one Hydroxyl number of preferably 100 to 500 suitably use Find. Linear and / or are preferably used as polyhydroxyl compounds branched polyester polyols and in particular linear and / or branched Polyoxyalkylene polyols are used, being made from polyhydroxyl compounds renewable natural substances and / or chemically modified regrowth natural products are particularly preferred. As lignin-free polyhydroxy yl compounds a) are also polymer-modified polyoxy alkylene polyols, polyoxyalkylene polyol dispersions and other hydroxyl groups Pen-containing polymers and polycondensates with the above-mentioned functionality ten and hydroxyl numbers, for example polyester amides, polyacetals and / or Polycarbonates, especially those made from diphenyl carbonate and hexane diol-1,6 are prepared by transesterification, or mixtures of at least two of the said higher molecular weight polyhydroxyl compounds a).

Suitable polyester polyols can, for example, from organic Dicarboxylic acids with 2 to 12 carbon atoms, preferably aliphatic Dicarboxylic acids with 4 to 6 carbon atoms and polyhydric alcohols, preferably alkanediols having 2 to 12 carbon atoms, preferably 2 up to 6 carbon atoms, dialkylene glycols and / or alkanetriols with 3 to 6 carbon atoms can be produced. As dicarboxylic acids come in Examples include: succinic acid, glutaric acid, adipic acid, suberic acid, Azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, Phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can can be used both individually and in a mixture. Instead of  Dicarboxylic acids can also the corresponding carboxylic acid derivatives, such as. B. Dicarboxylic acid esters of alcohols with 1 to 4 carbon atoms or Dicarboxylic anhydrides can be used. Preferably used Dicarboxylic acid mixtures of succinic, glutaric and adipic acids in Ratios of amounts of, for example, 20 to 35: 35 to 50: 20 to 32 Parts by weight, and in particular adipic acid. Examples of two and polyhydric alcohols, especially alkanediols and dialkylene glycols, are: Ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, glycerin and Trimethylolpropane. Ethanediol is preferably used, Diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerin or Mixtures of at least two of the alkane polyols mentioned, in particular e.g. B. Mixtures of 1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol. Polyester polyols made from lactones, e.g. B. ε-caprolactone or hydroxycarboxylic acids, e.g. B. ω-hydroxycaproic acid.

To produce the polyester polyols, the organic, for. B. aromatic and preferably aliphatic dicarboxylic acids and / or their Derivatives and the polyhydric alcohols and / or alkylene glycols catalyst free or preferably in the presence of esterification catalysts moderately in an atmosphere of inert gases, such as. B. nitrogen, Helium, argon and the like. a. in the melt at temperatures from 150 to 250 ° C, preferably 180 to 220 ° C, optionally under reduced pressure to to the desired acid number, which is advantageously less than 10, preferably is less than 2, be polycondensed. According to a preferred Embodiment is the esterification mixture in the above Temperatures up to an acid number of 80 to 30, preferably 40 to 30, under normal pressure and then under a pressure of less than 500 mbar, preferably 50 to 150 mbar, polycondensed. As Vereste tion catalysts come, for example, iron, cadmium, cobalt, lead,  Zinc, antimony, magnesium, titanium and tin catalysts in the form of Metals, metal oxides or metal salts into consideration. The polycondensation can, however, also in the liquid phase in the presence of diluent and / or Entraining agents such. As benzene, toluene, xylene or chlorobenzene azeotropic distillation of the condensation water can be carried out.

Organic dicarboxylic acids are used to produce the polyester polyols and / or their derivatives and the polyhydric alcohols advantageously in a molar ratio of 1: 1 to 1.8, preferably 1: 1.05 to 1.2, polycon densifies.

The polyester polyols obtained preferably have a functionality of 2 to 4, in particular 2 to 3, and a hydroxyl number of 240 to 30, preferably 180 to 40.

However, poly are used in particular as polyhydroxyl compounds oxyalkylene polyols, which are prepared by known processes, at for example by anionic polymerization with alkali metal hydroxides, such as Sodium or potassium hydroxide, or with alkali alcoholates such as sodium methylate, sodium or potassium ethylate or potassium isopropylate, as Kataly catalysts and with the addition of at least one starter molecule which contains 2 to 8, preferably contains 2 to 3 reactive hydrogen atoms bound, for Production of polyoxyalkylene polyols for flexible PUR foams, and preferably contains 3 to 8 reactive hydrogen atoms bound for forth Provision of polyoxyalkylene polyols for semi-hard and hard PUR foam substances, or by cationic polymerization with Lewis acids, such as Antimony pentachloride, boron fluoride etherate and the like. a. or bleaching earth as Catalysts of one or more alkylene oxides with 2 to 4 Carbon atoms in the alkylene radical.  

Suitable alkylene oxides are, for example, tetrahydrofuran, 1,3-propylene oxide, 1,2- or 2,3-butylene oxide and preferably ethylene oxide and 1,2-propylene oxide. The alkylene oxides can be used individually, alternately can be used in succession or as mixtures. As starter molecules For example, water, organic dicarboxylic acids, such as Succinic acid, adipic acid, phthalic acid and terephthalic acid, aliphatic and aromatic, optionally N-mono-, N, N- and N, N'-dialkyl substituted Diamines with 1 to 4 carbon atoms in the alkyl radical, such as optionally mono- and dialkyl-substituted ethylenediamine, diethylenetriamine, Triethylenetetramine, 1,3-propylenediamine, 1,3- or 1,4-butylenediamine, 1,2-, 1,3-, 1,4-, 1,5- and 1,6-hexamethylenediamine, phenylenediamines, 2,3-, 3,4-, 2,4- and 2,6-toluenediamine and 4,4'-, 2,4'- and 2,2'-diamino-diphenyl methane.

Other suitable starter molecules are: alkanolamines, such as, for. B. Ethanolamine, N-methyl and N-ethylethanolamine, dialkanolamines, such as. B. Diethanolamine, N-methyl- and N-ethyldiethanolamine and trialkanolamines, such as B. triethanolamine, and ammonia. Preferably used polyvalent, in particular two to eight, alcohols and / or Alkylene glycols such as B. ethanediol, 1,2-propanediol and 1,3, diethylene glycol, Dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerol, trimethylolpropane, Pentaerythritol, sorbitol and sucrose and mixtures of at least 2 polyhydric alcohols.

Suitable polyoxyalkylene polyols are polyoxyalkylene glycols, as described above have been described for the lignin-containing polyhydroxyl compounds, and furthermore polymer-modified polyoxyalkylene polyols, preferably graft poly oxyalkylene polyols, especially those based on styrene and / or acrylonitrile, by in-situ polymerization of acrylonitrile, styrene or preferably Mixtures of styrene and acrylonitrile, e.g. B. in a weight ratio of 90:10  to 10:90, preferably 70:30 to 30:70, suitably in the aforementioned polyoxyalkylene polyols analogous to the information in the German Patents 11 11 394, 12 22 669 (US 3 304 273, 3 383 351, 3 523 093), 11 52 536 (GB 10 40 452) and 11 52 537 (GB 9 87 618) as well as polyoxyalkylene-polyol dispersions, which are in the form of a disperse phase, usually in an amount of 1 to 50% by weight, preferably 2 to 25 % By weight, contain: e.g. B. polyureas, polyhydrazides, tert-amino groups bound containing polyurethanes and / or melamine and the z. B. Described are described in EP-B-011 752 (US-A-4,304,708), US-A-4,374,209 and DE-A-32 31 497.

Like the polyester polyols, the polyoxyalkylene polyols can be used individually or used in the form of mixtures. You can also use the graft polyoxyalkylene polyols or polyester polyols and the hydroxyl-containing polyester amides, polyacetals and / or Polycarbonates are mixed.

As polyacetals containing hydroxyl groups such. B. from glycols, such as Diethylene glycol, triethylene glycol, 4,4'-dihydroxyethoxy-diphenyldimethyl Compounds that can be prepared from methane, hexanediol and formaldehyde. Suitable poly can also be obtained by polymerizing cyclic acetals Produce acetals.

Polycarbonates containing hydroxyl groups are those of themselves known type into consideration, for example by reacting diols, such as B. propanediol (1,3), butanediol (1,4) and / or hexanediol (1,6), Diethylene glycol, triethylene glycol or tetraethylene glycol with Diaryl carbonates, e.g. B. diphenyl carbonate, or phosgene can.  

The polyester amides include e.g. B. from polyvalent, saturated and / or unsaturated carboxylic acids or their anhydrides and polyvalent saturated and / or unsaturated amino alcohols or Mi creations from polyhydric alcohols and amino alcohols and / or poly amine-derived, predominantly linear condensates.

The higher molecular weight polyhydroxyl compounds (a) can, depending on Ver intended use wholly or preferably partially by low molecular weight Chain extenders and / or crosslinking agents are replaced. In the Manufacture of flexible PUR foams can be modified the mechanical properties of the PUR foams, e.g. B. the hardness of Addition of chain extenders, crosslinking agents or given if mixtures of them also prove to be advantageous. In the manufacture of Rigid PUR foams can usually be due to the use of chains extenders and / or crosslinking agents are dispensed with. As chains extenders can be difunctional compounds, as crosslinking agents trifunctional and higher functional compounds each with molecular weights less than 400, preferably from 62 to about 300 may be used. Alkanediols, e.g. B. those with 2 to 6 carbon atoms in the alkylene radical, such as. B. ethane, 1,3-propane, 1,4-butane, 1,5-pentane and 1,6-hexanediol, and dialkylene glycol le, such as As diethylene, dipropylene and dibutylene glycol, and as Vernet agents alkanolamines, e.g. B. ethanolamine, dialkanolamine, e.g. B. Diethanol amine, and trialkanolamines, e.g. B. triethanolamine and triisopropanolamine, and trihydric and / or higher alcohols, such as. B. glycerin, trimethylolpropane and pentaerythritol. Suitable as chain extenders or crosslinking agents the low molecular weight ethoxylation and / or propoxylation products, e.g. B. those with molecular weights up to about 400, the front mentioned polyhydric alcohols, alkylene glycols, alkanolamines and aliphatic and / or aromatic diamines.  

Suitable lignin-containing polyhydroxyl compounds b) according to the invention the lignin-containing polyhydroxyl compounds as described above were.

Polyisocyanates c) which are suitable according to the invention are: alkylene diisocyanates with 4 to 12 carbon atoms in the alkylene radical, such as. B. 1,12-Dodecane diisocya nat, 2-ethyl-tetramethylene-1,4-diisocyanate, 2-methyl-pentamethylene-diisocya nat-1,5, 2-ethyl-2-butyl-pentamethylene-diisocyanate-1,5, tetramethylene diisocyanate nat-1,4 and preferably hexamethylene-diisocyanate-1,6; cycloaliphatic Diisocyanates such as B. cyclohexane-1,3- and 1,4-diisocyanate and any Mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane (isophorone diisocyanate), 2,4- and 2,6-hexahydrotoluylene diisocya nat and the corresponding isomer mixtures, 4,4'-, 2,2'- and 2,4'-dicyclohexylmethane diisocyanate and the corresponding Mixtures of isomers, and preferably aromatic di- and polyisocyanates, such as B. 2,4- and 2,6-tolylene diisocyanate and the corresponding Mixtures of isomers, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate and the corresponding mixtures of isomers, mixtures of 4,4'- and 2,4'-diphenylmethane diisocyanates, polyphenyl polymethylene polyisocyanates, Mixtures of 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates and Polyphenyl polymethylene polyisocyanates (raw MDI) and mixtures of Crude MDI and tolylene diisocyanates. The organic di and poly isocya nates can be used individually or in the form of their mixtures.

Mixtures of have proven particularly useful as organic polyisocyanates Diphenylmethane diisocyanates and polyphenyl polymethylene polyisocyanates, preferably those with a diphenylmethane diisocyanate content of min at least 35% by weight, e.g. B. from 45 to 95 wt .-% and in particular from 48 to 60 wt .-%, so that such raw MDI compositions in particular preferred application.  

Preferred chain extenders d) are alkanediols, in particular 1,4-butanediol and / or 1,6-hexanediol, alkylene glycols, especially ethylene glycol and propylene glycol, and as a crosslinking agent trihydric alcohols, especially glycerin and trimethylolpropane, Dialkanolamines, especially diethanolamine, and trialkanolamines, especially triethanolamine.

The chain extenders and / or crosslinking agents d), which are preferred be used for the production of flexible PUR foams, can for example in amounts of 2 to 60 wt .-%, preferably of 10 to 40 wt .-%, based on the weight of the higher molecular weight Ver bindings a), are used.

Suitable blowing agents e) for producing the cellular polyurethanes Water and / or gases present in liquid form at room temperature and liquids which are compared to mixtures of components a), b) and c) are inert and boiling points below 50 ° C, especially between -50 ° C and 30 ° C at atmospheric pressure, and mixtures of gaseous and liquid blowing agents. Examples of such preferably usable gases and liquids are alkanes, such as. B. propane, n- and iso-butane, n- and iso-pentane, preferably technical mixtures of n- and iso-pentane, and cycloalkanes, such as. B. cyclopentane, alkyl ethers such as. B. Dimethyl ether, diethyl ether and methyl isobutyl ether, carboxylic acid alkyl esters, such as As methyl formate, and halogenated hydrocarbons, such as. B. Dichlorofluoromethane, trifluoromethane, 1,1-dichloro-1-fluoroethane, monochlor trifluoroethane, monochlorodifluoroethane, difluoroethane, dichlorotrifluoroethane, Monochlorotetrafluoroethane, pentafluoroethane, tetrafluoroethane and dichloromono fluoroethane. For the production of cellular polyurethanes, preferably PUR Foams are used, in particular water, linear and cyclic Alkanes with 5 to 7 carbon atoms and mixtures thereof. The exemplary  blowing agents mentioned can be used individually or as mixtures the. Chlorofluorocarbons are not used as blowing agents, that damage the ozone layer.

Used in a mixture with liquids with boiling points below 50 ° C can also be (cyclo) alkanes, such as. B. hexane and cyclohexane and Carboxylic acid alkyl esters, such as. B. ethyl formate, with boiling points above 50 ° C, if the blowing agent mixture expediently has a boiling point below 38 ° C. having. The required amount of blowing agent or mixture can depending on the type of blowing agent or blowing agent mixture and the mixing ratios experimentally determined in a simple manner will. The blowing agents are usually used in an amount of 0.1 to 30 parts by weight, preferably from 1 to 25 parts by weight, based on 100 Parts by weight of components a-c used.

Catalysts f) which can be used in the production of PUR, are preferably compounds that react the hydroxyl groups containing components a) and b) with the organic polyisocyanate accelerate component c) strongly. Possible catalysts e.g. B. organic metal compounds, preferably organic tin compounds gene, such as tin (II) salts of organic carboxylic acids, e.g. B. tin (II) diacetate, Tin (II) dioctoate, tin (II) diethylhexoate and tin (II) dilaurate and the dialkyl Tin (IV) salts of organic carboxylic acids, e.g. B. dibutyltin diacetate, Dibutyltin dilaurate, dibutyltin maleate, dioctyltin diacetate, and dibutyltin dimercaptid and strongly basic amines, for example amidines, such as. B. 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines, such as. B. Triethyl amine, tributylamine, dimethylbenzylamine, N-methyl, N-ethyl, N-cyclo hexylmorpholine, dimorpholino-diethyl ether, N, N, N ', N'-tetramethylethylene diamine, N, N, N ', N'-tetramethylbutane diamine, N, N, N', N'-tetramethylhexane diamine-1,6, di- (4-N, N-dimethylaminocyclohexyl) methane, pentamethyldiethy  lentriamine, tetramethyldiaminoethyl ether, bis (dimethylaminopropyl) urea, Dimethylpiperazine, 1,2-dimethylimidazole, 1-azabicyclo [3.3.O] octane, Alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyl and N-ethyl-diethanolamine and dimethylethanolamine, tris- (N, N-dialkylamino alkyl) -s-hexahydrotriazines, especially tris- (N, N-dimethylaminopropyl) -s-hexa hydrotriazine, tetraalkylammonium hydroxides, such as tetramethylammoni umhydroxide and preferably 1,4-diaza-bicyclo [2.2.2] octane. Preferably 0.001 to 5% by weight, in particular 0.05 to 2% by weight, are used Catalyst or catalyst combination, based on the total weight of the Components a) to g).

The reaction mixture for the production of the compact or cellular poly Urethanes, preferably PUR foams, can also be used if necessary Aid g) are incorporated. Surfaces are mentioned, for example active substances, foam stabilizers, cell regulators, flame retardants, Fillers, dyes, pigments, antistatic agents, hydrolysis inhibitors, fungi static and bacteriostatic substances.

As surface-active substances such. B. connections into consideration which may be suitable, the cell structure of the PUR foams to regulate. Examples include emulsifiers such as Natri salts of castor oil sulfates or of fatty acids, and salts of fat acids with amines, e.g. B. oleic acid diethylamine, stearic acid diethanolamine, ricinoleic acid diethanolamine, salts of sulfonic acids, e.g. B. alkali or Ammonium salts of dodecylbenzene or dinaphthylmethane disulfonic acid, and Ricinoleic acid; Foam stabilizers, such as siloxane-oxalkylene copolymers and other organopolysiloxanes, ethoxylated alkylphenols, ethoxylated Fatty alcohols, paraffin oils, castor oil or ricinoleic esters, Turkish red oil and Peanut oil and cell regulators such as pyrogenic silica, paraffins, fatty alcohols and dimethylpolysiloxanes. To improve the emulsifying effect, the cell  Structure and / or stabilization of the foam are also suitable for oligomers Polyacrylates with polyoxyalkylene and fluoroalkane residues as side groups. The Surfactants are usually used in amounts from 0.01 to 5 parts by weight, based on 100 parts by weight of components a) to g), applied.

Suitable flame retardants are, for example, diphenyl cresyl phosphate, Tricresyl phosphate, tris (2-chloroethyl) phosphate, tris (2-chloropropyl) phosphate, Tris (1,3-dichloropropyl) phosphate, tris (2,3-dibromopropyl) phosphate and tetra kis (2-chloroethyl) ethylene diphosphate.

In addition to the halogen-substituted phosphates mentioned, inorganic cal flame retardants such. B. alumina hydrate, antimony trioxide, Arsenic oxide, ammonium polyphosphate, expandable graphite and calcium sulfate, or Cyanuric acid derivatives, such as. B. melamine, or mixtures of at least two flame retardants such as B. ammonium polyphosphates and melamine and / or expanded graphite, and optionally starch for flame retardancy of the PUR foams produced according to the invention are used. in the in general, it has proven to be expedient to use 5 to 50 parts by weight, preferably 10 to 40 parts by weight of said flame retardants or Mixtures for 100 parts by weight of components a) to c) use.

As fillers, in particular reinforcing fillers, they are per se known, conventional organic and inorganic fillers and Understand reinforcing agents. The following are examples: inorganic fillers such as B. silicate minerals, for example Layered silicates such as antigorite, serpentine, hornblende, amphibole, chrysotile, Zeolites, talc; Metal oxides such as B. kaolin, aluminum oxides, Aluminum silicate, titanium oxides and iron oxides, metal salts such as. B. chalk,  Heavy spar and inorganic pigments such as cadmium sulfide, zinc sulfide, as well as glass particles. Organic fillers come in, for example Consideration: carbon black, melamine, rosin, cyclopentadienyl resins and Graft polymers.

The inorganic and organic fillers can be used individually or as Mixtures are used and are the reaction mixture advantageously in amounts of 0.5 to 50% by weight, preferably 1 to 10 % By weight, based on the weight of components a) to c), is incorporated.

Details of the other usual aids mentioned above g) are the specialist literature, for example the monograph by J.H. Saunders and K.C. Fresh "High Polymers" Volume XVI, Polyurethanes, Parts 1 and 2, Verlag Interscience Publishers 1962 or 1964, or the plastic hand book, Polyurethane, Volume VII, Carl-Hanser-Verlag, Munich, Vienna, 1. and 2nd edition, 1966 and 1983.

By using the lignin with a high salt content, a lignin containing polyhydroxy compound are produced, the optimal cocatalytic Possesses properties and the production of PUR foams, in particular rigid PUR foams with excellent processing and material properties properties such as reduced thermal conductivity and better heat retention ability. Here, a not inconsiderable proportion of the catalytic converter goal quantity can be saved. Especially in the manufacture of insulation Foam systems can be set to keep at constant tener setting time faster curing with improved flowability enable. With a short setting time, higher core densities or a more uniform density distribution in foams can be achieved. It is also continuous processing, e.g. B. Continuous isolation of District heating pipes possible with short setting times. The invention  PUR foams are particularly suitable as insulating and Support foam in sandwich elements with flexible or rigid cover layers, as insulating foams in the cooling or heating area and as spray and spray foam in construction.

Further preferred features and embodiments of the invention result from the following examples.

In the examples, all viscosities were determined using a rotation viscometer determined at 25 ° C.

Examples

By mixing a polyol component (component A) with a Isocyanate mixture (component B), PUR foams were produced and examined their properties. Experiments were carried out with Lignin-containing polyhydroxyl compounds in component A (fiction according to examples) and those without lignin-containing polyhydroxyl compounds (Comparative examples).

In the preparation of component A in Examples 1 to 8, the following constituents were used in accordance with Tables 1 and 2 below:

A is a 4.5-functional sorbitol-propylene glycol-propylene oxide-polyether rol with a hydroxyl number of 490 mg KOH / g sample and a viscosity at 25 ° C of 4200 mPas
B is a 2-functional propylene glycol propylene oxide polyetherol with a hydroxyl number of 180 mg KOH / g sample and a viscosity at 25 ° C of 115 mPas
A 4.5-functional sucrose-glycerol-propylene oxide polyether ol with a hydroxyl number of 410 mg KOH / g sample and a viscosity at 25 ° C of 6700 mPas
C a polyol based on Zewa lignin and propylene oxide, which was produced as indicated below, with a hydroxyl number of 439 mg KOH / g sample and a viscosity of 1004 mPas (preparation as indicated below)
D a polyol based on Zewa lignin and propylene oxide with a hydroxyl number of 408 mg KOH / g sample and a viscosity of 563 mPas (production as indicated below)
F chain extender, a mixture of 1,4-butanediol with trimethylpropane,
Stabilizer Foam stabilizer based on silicone (Tegostab® B 8409 from Goldschmitt AG, Essen)
Catalyst N, N-dimethyl-cyclohexylamine.

The polyol C was prepared from 800 parts by weight of Zewa lignin (natri um-Ligninsulfonat 220 Zewa EF from Lignotech) with a salt content of 6700 ppm, measured as Na and K ion content, 200 parts by weight a polyethylene glycol with a hydroxyl number of 185 mg KOH / g, 100 Parts by weight of glycerin and 800 parts by weight of propylene oxide.  

Polyol D was made from 600 parts by weight of Zewa lignin (such as defined under polyol C) with a salt content of 9500 ppm, measured as Na and K ion content, 200 parts by weight of a polypropylene glycol a hydroxyl number of 100 mg KOH / g, 50 g parts by weight of glycerol, 400 Parts by weight of ethylene oxide and 400 parts by weight of propylene oxide.

As component B was a polyisocyanate containing urethane groups mixture of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates (raw MDI) with an NCO content of 31.5 percent by weight used.

For preparation of the PU foams, components A and B by means of a stirrer Vollrath the number of revolutions 1800 min ^-1 (the tables below to the invention) mixed at an index of 133 and 118 were intensively, wherein

Index = (mol [NCO] / mol [OH]) × 100, ie
Index <100 corresponds to an excess of [NCO];
Index <100 corresponds to an excess of [OH];
Index = 100 corresponds to an equivalent amount of [NCO] and [OH].

The reaction mixture was used to determine the pot, setting and Rise time in a paper cup with a content of 660 ml and one filled the upper diameter of 9 cm and let it foam there.

The results are shown in Tables 1 and 2 below, the determination methods used in the tests being defined in more detail below.

Table 1

Table 2

free density ¹ density determination according to DIN 53420
Boltzest ² Measurement of the maximum impression force in the freshly foamed foam with a pin of 20 mm diameter and a spherical cap (radius 10 mm) as an impression surface at 10 mm feed depending on the time after mixing the components to foam. Higher impression forces indicate better curing.
Mold foaming ³ Entry of the reacting mixture into a mold at 45 ° C with dimensions of 300 mm × 400 mm × 80 mm. The molded body has a total density of 70 ± 1 kg / m ³ .
Core density ⁴ density inside the molded body in kg / m ³ , measured according to DIN 53420
WLZ ⁵ thermal conductivity at 23 ° C mean temperature (Ana con) immediately (24 h) after foaming and after 7 days of storage
WFB ⁶ heat resistance according to DIN 18 164 24 h at 150 ° C and 0.04 N / mm ²
Open cell ⁷ according to ASTM 2856, uncorrected
Hose test ⁸ Immediately after the components had been mixed, 100 g of the reacting mixture were placed in an endless hose made of a plastic film with a diameter of 4.5 cm. The hose was clamped on one side and the foam length achieved in cm was taken as a measure of the flowability, with a longer foam length meaning better flow.

The results in the tables show that the inventive Lignin-containing polyhydroxyl compounds for the production of PUR foam bodies that have improved properties. especially the increased impression power, better heat resistance, higher core density and lower thermal conductivity are remarkable.

Claims (15)

1. Lignin-containing polyhydroxyl compound, characterized in that it is obtainable from the reaction

• b1) a solution that contains
• b11) Lignin with a salt content, measured as Na and K ion content, between 5000 and 15000 ppm and
• b12) at least one polyoxyalkylene glycol, selected from the group of the polyoxypropylene-polyoxyethylene glycols, poly oxypropylene glycols, mixtures thereof, and mixtures thereof with polyhydroxyl compounds with an OH functionality of, 2, and if appropriate
• b13) at least one OH, NH and / or NH ₂ -functional compound with an H functionality of ≧ 2 with
• b2) at least one alkylene oxide.

2. Lignin-containing polyhydroxyl compound according to claim 1, characterized ge indicates that polyoxyalkylene glycols b12) with a molecular Ge important from 400 to 4000, preferably from 600 to 1500, used whose polypropylene oxide content is 0 to 50%, preferably 0 to 20% and in particular 0 to 10%.   3. Lignin-containing polyhydroxyl compound according to claim 1 or 2, characterized characterized in that the alkylene oxide b2) used is <50% Alkylene oxide with at least 3 carbon atoms, in particular propylene oxide. 4. Lignin-containing polyhydroxyl compound according to one of claims 1 to 3, characterized in that the lignin b11) used a Salinity, measured as Na and K ion content, between 5000 and Has 12,000 ppm. 5. Lignin-containing polyhydroxyl compound according to one of the preceding Claims, characterized in that the compound b13) is a two or higher functional alcohol, a sugar alcohol, saccharide, aminoal is alcohol or an aliphatic or aromatic amine. 6. Use of the lignin-containing polyhydroxyl compound according to one of the claims directed to lignin-containing polyhydroxyl compounds the production of polyurethane. 7. Process for the preparation of a lignin-containing polyhydroxyl compound for one of the lignin-containing polyhydroxyl compounds Claims characterized by the implementation of the on lignin-hal term polyhydroxyl compounds defined claims Solution b1) and the alkylene oxides b2). 8. The method according to claim 7, characterized in that at the beginning of Alkoxylation reaction as long as at least 50% of the total used amount of alkylene oxide were implemented, only alkylene oxides with at least 3 carbon atoms, in particular propylene oxide, with the Solution b1) are implemented.   9. The method according to claim 7 or 8, characterized in that the solution b1) before the reaction with the alkylene oxides b2) a temperature of 80 to 130 ° C, preferably under a pressure from a maximum of 30 mbar over a period of 1 to 8 hours delt. 10. The method according to any one of claims 7 to 9, characterized in that the reaction with the alkylene oxides b2) without or in the presence acidic and / or basic catalysts, preferably without additives of catalysts. 11. Process for the production of compact or flexible polyurethanes, preferably polyurethane foams, by reacting

• a) higher molecular weight compounds with at least two reactive hydrogen atoms, preferably polyhydroxyl compounds, and
• b) Lignin-containing polyhydroxyl compounds
• c) organic polyisocyanates and / or modified organic polyisocyanates,
  in the presence or absence of
• d) chain extenders and / or crosslinking agents,
• e) blowing agents,
• f) catalysts and
• g) aids,
  characterized in that the lignin-containing polyhydroxyl compounds b) are the lignin-containing polyhydroxyl compounds according to one of the claims directed to the lignin-containing poly hydroxyl compounds.

12. The method according to claim 11, characterized in that the higher mo lecular connections a) a functionality of 2 to 8 and one  Have hydroxyl number from 25 to 500, preferably made of polyhydroxy yl compounds exist which are selected in particular from the Group of polythioether polyols, polyester amides, hydroxyl groups containing polyacetals, hydroxyl-containing aliphatic polycarbonates, Polyester polyols, polyether polyols, polymer-modified polyethers polyols, preferably polyether polyols and mixtures of at least two of the polyhydroxyl compounds mentioned. 13. The method according to claim 11 or 12, characterized in that one as blowing agent e) water, linear and cyclic alkanes with 3 to 7 C- Atoms or mixtures thereof are used. 14. The method according to one of the dishes on the production of polyurethane ten claims, characterized in that the polyurethane by Implementation of the high molecular compounds a) and the lignin halti gene polyhydroxyl compounds b) with the polyisocyanate together settlements c) in the presence of a blowing agent e) and with training of a polyurethane foam body is obtained in a mold. 15. Compact or cellular polyurethanes, especially polyurethane foams obtainable according to one of the claims 11 to 14 described method.