Phosphorus-containing flame retardants

Abstract

To provide a phosphorus-containing polyol that gives polyurethane flame retardancy.SOLUTION: The present invention relates to a phosphorus-containing polyol obtained by a process comprising the reaction of at least one polyol with a phosphorus-containing compound of a specific structure, the phosphorus-containing polyol containing at least one phosphorus-containing group of the general formula (II) [Y represents O or S, t is 0 or 1, R1 and R2 independently represent alkyl, alkenyl, alkoxy, cycloalkyl, aryl, aryloxy or the like], wherein the polyol is selected from the group consisting of a polyether polyol, a polyester polyol, and a mixture thereof; the phosphorous-containing polyol has an OH-functionality of from 2 to 4 and a molecular weight of from 100 to 700 g / mol; a phosphorus content of the phosphorous-containing polyol is at least 7 mass%; and the phosphorous-containing polyol is free of halogen.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to phosphorus-containing polyols obtained or obtained by a process comprising the reaction of at least one polyol with a phosphorus-containing compound of general formula (I) as defined herein, and a process for preparing phosphorus-containing polyols comprising the reaction of at least one polyol with a phosphorus-containing compound of general formula (I).Furthermore, the present invention relates to the use of the phosphorus-containing polyols disclosed herein as flame retardants, to a process for preparing polyurethanes, and to the polyurethanes themselves. [Background technology]

[0002] There are many different ways to make polymers, specifically polyurethanes, and more specifically polyurethane foams, flame retardant. The first way is the formation of a crust to prevent the flame from reaching the combustible material. The pyrohydrolysis products remove oxygen from the polymer matrix, causing the formation of a carbon layer on the surface of the polymer. This carbon layer prevents the flame from causing either thermal or oxidative degradation of the plastic located below the layer. The term used is intumescence. Phosphorus-containing compounds and these organophosphorus compounds together are widely used because they form a charred crust in the event of a fire. Organophosphorus flame retardants are mainly based on phosphates, phosphonates, or phosphites.

[0003] Halogen compounds are also used as flame retardants. In contrast to phosphorus-containing flame retardants, they act in the gas phase of the flame. Here, the less reactive free halogen radicals scavenge the various more reactive free radicals resulting from the decomposition products of the polymer, thus inhibiting flame propagation by the free radicals. Here, bromine-containing flame retardants are particularly effective. Another effective flame retardant is trichloroisopropyl phosphate (TCPP), which contains not only phosphoric acid but also the halogen chlorine, and thus acts by both of the above mechanisms.

[0004] However, halogen-based flame retardants, especially bromine-containing flame retardants, are undesirable for toxicological, environmental, and regulatory reasons. Halogen-containing flame retardants also increase smoke density during a fire. Thus, attempts are being made to achieve a total avoidance of halogen-containing flame retardants.

[0005] Examples of known halogen-free flame retardants are solid flame retardants such as melanin or ammonium polyphosphate. These solid particles have a negative effect on the properties of polymers, especially polyurethane foams. Solid flame retardants also cause problems, especially during the production of polyurethanes. By way of example, the production of polyurethanes preferably uses liquid starting materials, including those in the form of solutions. The use of solid particles leads to separation phenomena in the mixtures normally used in the production of polyurethanes, so that the shelf life of the batches is about one day. Furthermore, solid flame retardant particles wear out metering units, for example in foaming plants. The flame retardants also have a negative effect on the chemical processes during the foaming process and on the properties of the foam.

[0006] Many liquid flame retardants, such as triethyl phosphate (TEP) or diethyl ethane phosphonate (DEEP), for example, impart these unpleasant odors and contribute to emissions from plastics. Furthermore, liquid flame retardants have a negative effect on the foaming reaction during the production of polyurethane foams and on the properties of the foam, such as the mechanical properties. Known liquid flame retardants often also act as plasticizers.

[0007] To address the issues related to emissions, incorporateable flame retardants have been developed for polyurethanes. Incorporable flame retardants, such as Exolit® OP560 (Clariant), generally have a functionality of 2 or less relative to the isocyanate and often reduce the crosslink density in polyurethane foams, thereby compromising foam properties, especially in rigid polyurethane foams.

[0008] WO2003 / 104374A1, WO2004 / 076509A2, and WO2005 / 052031A1 describe the use of phosphonic acid-reacted hyperbranched polyacrylonitrile polyacrylamides, polyamides, and polyamines as rust inhibitors, lubricants, fiber additives, and flame retardants. The nitrogen-containing structures severely affect the catalytic reaction of the foam-forming process, so the compounds are not suitable for use in polyurethanes, and in particular polyurethane foams.

[0009] WO2010 / 080425A1 discloses a method for making hydroxymethyl phosphonate, comprising the steps of heating paraformaldehyde in a solvent to a desired reaction temperature, the solvent being present in at least an amount necessary to dissolve or suspend the paraformaldehyde; adding at least one alkyl phosphite to the heated paraformaldehyde to provide hydroxymethyl phosphonate, the alkyl phosphite being added to the heated paraformaldehyde at a rate that avoids or suppresses significant heat generation and resulting high / significant levels of acid by-products, and in the reaction medium, there is present at least one hindered amine catalyst, in which the nitrogen in the amine is directly bonded to the secondary and / or tertiary carbon of an organic group; and optionally, after the completion of the addition, heating the reaction mixture to an elevated temperature. The use of the obtained product for the preparation of polyurethane is also disclosed. The obtained polyurethane shows problems related to formaldehyde emissions.

[0010] In EP 474076 B1, Bayer AG describes highly branched polyphosphates, made with aromatic dihydroxy compounds and with phosphonic acid esters or polyphosphorus compounds, as flame retardants for polycarbonates. The structure of these substances gives them low solubility in the polyols used in polyurethane production, which makes it difficult to process this type of compound in polyurethanes.

[0011] WO2007 / 066383 describes hyperbranched polyesters reacted with phosphorus compounds, such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide, and their use as flame retardants for resins. The low thermal and hydrolytic stability of the ester groups is a disadvantage. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] WO2003 / 104374A1 [Patent Document 2] WO2004 / 076509A2 [Patent Document 3] WO2005 / 052031A1 [Patent Document 4] WO2010 / 080425A1 [Patent Document 5] EP474076B1 [Patent Document 6] WO2007 / 066383 Summary of the Invention [Problem to be solved by the invention]

[0013] It was therefore an object of the present invention to provide a halogen-free flame retardant which can also be used in the production of polyurethanes.

[0014] Another object of the present invention was to provide a flame retardant, the use of which in polymers, in particular polyurethanes, in particular polyurethane foams, does not lead to emissions and the use of which in polymers, in particular polyurethanes, in particular polyurethane foams, does not lead to impairment of the properties, in particular the mechanical properties. [Means for solving the problem]

[0015] The object of the present invention is to provide a process for the preparation of a polyol comprising at least one polyol and a polyol of general formula (I): [ka] [In the formula, X represents Cl, Br, I, alkoxy, or hydrogen; Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] This is accomplished by a phosphorus-containing polyol obtained or obtained by a process comprising reacting the phosphorus-containing compound of

[0016] The phosphorus-containing polyol according to the present invention comprises at least one polyol and a polyol having the general formula (I): [ka] [In the formula, X represents Cl, Br, I, alkoxy, or hydrogen; Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] with a phosphorus-containing compound, which may also be prepared by the process of the present invention.

[0017] As a solution, the phosphorus-containing polyol according to the present invention is found based on the partial phosphorylation of polyalcohol.The synthesis is a simple one-step reaction based on cheap raw materials.Due to the variety of polyols that can be used as starting materials, a wide range of phosphorus-containing polyols can be easily obtained in order to adjust the performance and processing as desired.

[0018] The phosphorus-containing polyols according to the invention act as flame retardants and can simultaneously improve mechanical properties (or prevent the deterioration of properties observed in association with non-reactive flame retardants), which are influenced not only by the phosphorus content but also by the OH-functionality and the type of polyalcohol which shows synergistic effects.

[0019] By varying the degree of partial phosphorylation, the hydroxyl value of the hyperbranched molecule can be adjusted to the OH value typical for either flexible or rigid foams. Thus, the phosphorus-containing polyol can be easily mixed with common polyols and presents minimal blowing hindrance. Thus, tailor-made flame retardants for flexible and rigid polyurethane foams are provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The phosphorus-containing polyol of the present invention comprises at least one phosphorus-containing group. The at least one phosphorus-containing group preferably has the general formula (II): [ka] [In the formula, Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] is the basis.

[0021] R1 and R2 are the same or different and are preferably C1-C16-alkyl, C1-C16-alkoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, or aryloxy. Y is preferably O and t is preferably 1.

[0022] It is particularly preferred that R1 and R2 are the same and are each phenyl, methoxy-phenyl, tolyl, furyl, cyclohexyl, phenoxy, benzyl, benzyloxy, ethoxy, or methoxy.

[0023] The phosphorus-containing polyol may also contain two or more different phosphorus-containing groups, preferably two or more different groups of general formula (II), said phosphorus being preferably present in the form of a phosphate or phosphinate group.

[0024] Thus, according to a further embodiment, the present invention is directed to a phosphorus-containing polyol as disclosed above, wherein said phosphorus is present in the form of a phosphate group or a phosphinate group.

[0025] To prepare the phosphorus-containing polyols according to the present invention, which contain at least one phosphorus-containing group, preferably at least one polyol is selected from the group consisting of polyols represented by the general formula (I): [ka] [In the formula, X represents Cl, Br, I, alkoxy, or hydrogen; Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] The phosphorus-containing compound is reacted with the phosphorus-containing compound.

[0026] Compounds of formula (I) are known, commercially available or can be prepared by using synthetic routes well known in the literature, for example as described in Science of Synthesis 42 (2008); Houben Weyl E1-2 (1982); Houben Weyl 12 (1963-1964).

[0027] The reaction of at least one polyol and the phosphorus-containing compound of general formula (I) may be carried out in the presence of a base.

[0028] Examples of suitable bases are metal hydrides such as sodium hydride, or non-nucleophilic amine bases such as triethylamine or Hunig's base, bicyclic amines such as DBU, N-methylimidazole, or substituted pyridines such as N-methylmorpholine, N-methylpiperidine, pyridine, or lutidine. Triethylamine and N-methylimidazole are particularly preferred. Here, the amount of base that can be used is generally equimolar. However, the base can also be used in excess or, where appropriate, as a solvent.

[0029] The polyol used for the preparation of the phosphorus-containing polyol according to the invention can generally be any suitable polyol having at least two reactive hydrogen atoms, for example having a functionality of 3 to 8, preferably 3, 4 or 5, and preferably having a molecular weight of 100 to 700. Thus, for example, a polyol selected from the group of polyether polyols, polyester polyols, and mixtures thereof can be used.

[0030] The phosphorus-containing polyols of the present invention therefore preferably have an OH-functionality of 0 to 8, preferably 1 to 5, in particular 2, 3 or 4. Thus, according to a further embodiment, the present invention is directed to the phosphorus-containing polyols disclosed above, wherein said phosphorus-containing polyols have an OH-functionality of 0 to 8.

[0031] Furthermore, the phosphorus-containing polyol of the present invention preferably has a molecular weight of 100 to 700 g / mol.Accordingly, according to a further embodiment, the present invention is directed to the phosphorus-containing polyol disclosed above, wherein said phosphorus-containing polyol has a molecular weight of 100 to 700 g / mol.

[0032] By way of example, polyetherols are prepared from epoxides such as propylene oxide and / or ethylene oxide or from tetrahydrofuran by using starting compounds containing active hydrogen, such as aliphatic alcohols, phenols, amines, carboxylic acids, water, or compounds based on natural substances, such as sucrose, sorbitol, or mannitol, with the use of catalysts. Preferably, polyetherols prepared from propylene oxide and / or ethylene oxide are used as polyols.

[0033] The polyol preferably has an OH number in the range of 2 to 800 mg KOH / g, in particular in the range of 25 to 250 mg KOH / g, more particularly in the range of 100 to 150 mg KOH / g.

[0034] The reacted amount of starting material is generally stoichiometric with respect to the desired degree of functionalization. It may be advantageous to use an excess of phosphorus component with respect to the hydroxyl functionality of polyol. Random partial phosphorylation can be achieved by using less than stoichiometric amount of phosphorus component. The ratio of starting materials used is such that the phosphorus content of the phosphorus-containing polyol of the present invention that contains at least one phosphorus-containing group is preferably at least 3% by weight, particularly preferably at least 5% by weight, in particular at least 7% by weight.

[0035] The phosphorus content of the phosphorus-containing polyol of the invention, which preferably comprises at least one phosphorus-containing group, is at least 3% by weight, particularly preferably in the range of 4-12% by weight, and even more preferably in the range of 6-9% by weight.Accordingly, according to a further embodiment, the present invention is directed to the phosphorus-containing polyol disclosed above, wherein said phosphorus-containing polyol has a phosphorus content of 3-12% by weight, based on the total weight of the phosphorus-containing polyol.

[0036] In parallel with the amount of the compound of formula (I), another prerequisite for the phosphorus content defined herein is the presence of sufficient OH groups in the phosphorus-containing polyol.These amounts can be adjusted through the appropriate implementation of the reactions during the preparation of the phosphorus-containing polyol, in particular through the ratio of at least trifunctional polyols and reaction time, which control the conversion and thus the molecular weight of the resulting polyol.Here, all or part of the OH groups in the polyol can be reacted with the phosphorus component.

[0037] Here, the reaction for preparing the phosphorus-containing polyols of the invention containing at least one phosphorus-containing group is preferably carried out in the presence of a solvent. Suitable solvents for the phosphorylation reaction are inert organic solvents such as DMSO, halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane or chlorobenzene. Further suitable solvents are ethers such as diethyl ether, methyl tert-butyl ether, dibutyl ether, dioxane or tetrahydrofuran. Further suitable solvents are hydrocarbons such as hexane, benzene or toluene. Further suitable solvents are nitriles such as acetonitrile or propionitrile. Further suitable solvents are ketones such as acetone, butanone or tert-butyl methyl ketone. It is also possible to use mixtures of said solvents or to operate without solvent.

[0038] The reaction is usually carried out at a temperature of from 0°C to the boiling point of the reaction mixture, preferably from 0 to 110°C, particularly preferably from room temperature to 110°C.

[0039] The reaction mixture is worked up in the usual way, for example by filtration, mixing with water, separation of the phases and, if appropriate, chromatographic purification of the crude product. The product may take the form of a thick oil which is freed of volatile components or purified at reduced pressure and slightly elevated temperature. To the extent that the resulting product is a solid, purification methods can also use recrystallization or digestion.

[0040] The phosphorus-containing polyols of the present invention, which contain at least one phosphorus-containing group, are used as flame retardants. The phosphorus-containing polyols of the present invention can be used in crosslinked polymers, for example polyurethanes, such as polyurethane foams.

[0041] When the phosphorus-containing polyol of the present invention containing at least one phosphorus-containing group is used in thermoplastics, including thermoplastic polyurethanes, the phosphorus-containing polyol of the present invention containing at least one phosphorus-containing group in each case contains less than 10%, particularly preferably less than 2% of free OH groups, more particularly no free OH groups, based on the total of phosphorus-containing groups and OH groups.This is achieved through the reaction of the phosphorus-containing polyol of the present invention with a compound of general formula (II) in a suitable ratio.

[0042] For the purposes of the present invention, polyurethanes include all known polyisocyanate polyaddition products. These include adducts of isocyanates and alcohols, and they may contain isocyanurate structures, allophanate structures, urea structures, carbodiimide structures, uretonimine structures, and biuret structures, and also modified polyurethanes that may contain isocyanate adducts. These polyurethanes of the present invention include in particular solid polyisocyanate polyaddition products, such as thermosets, and foams based on polyisocyanate polyaddition products, such as flexible foams, semi-rigid foams, rigid foams, or integral foams, as well as polyurethane coatings and binders. For the purposes of the present invention, the term polyurethane also includes polymer blends containing polyurethanes and further polymers, and foams made of said polymer blends. It is preferred that the phosphorus-containing polyols of the present invention, which contain at least one phosphorus-containing group, are used to produce polyurethane foams.

[0043] For the purposes of the present invention, polyurethane foams are foams according to DIN 7726. The compressive stress values ​​for flexible polyurethane foams according to the present invention at 10% compression, or the compressive strength of these foams, according to DIN 53421 / DIN EN ISO 604 are below 15 kPa, preferably between 1 and 14 kPa, in particular between 4 and 14 kPa. The compressive stress values ​​for semi-rigid polyurethane foams according to the present invention at 10% compression according to DIN 53421 / DIN EN ISO 604 are greater than 15 kPa to less than 80 kPa. The open-cell factor according to DIN ISO 4590 of the semi-rigid polyurethane foams according to the present invention and of the flexible polyurethane foams according to the present invention is preferably greater than 85%, particularly preferably greater than 90%. Further details regarding the flexible polyurethane foams of the invention and the semi-rigid polyurethane foams of the invention can be found in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapter 5.

[0044] The compressive stress values ​​for the rigid polyurethane foams of the invention at 10% compression are greater than 80 kPa, preferably greater than 120 kPa, particularly preferably greater than 150 kPa. Furthermore, the closed-cell factor of the rigid polyurethane foams according to DIN ISO 4590 is greater than 80%, preferably greater than 90%. Further details regarding the rigid polyurethane foams of the invention can be found in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapter 6.

[0045] For the purposes of the present invention, elastic polyurethane foams are polyurethane foams according to DIN 7726 which, after 10 minutes of a brief deformation to 50% of their thickness, do not exhibit a residual deformation of more than 2% of their initial thickness according to DIN 53577. The foams may be rigid, semi-rigid or flexible polyurethane foams.

[0046] Integral foams are polyurethane foams according to DIN 7726 that have a peripheral zone with a higher density than the center as a result of the molding process, where the overall density averaged over the center and peripheral zone is preferably greater than 100 g / L. For the purposes of the present invention, integral polyurethane foams can also be rigid, semi-rigid or flexible polyurethane foams. Further details regarding the integral polyurethane foams of the present invention can be found in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapter 7.

[0047] Here, the polyurethanes are obtained by mixing an isocyanate (a), a polyol (b), a phosphorus-containing polyol (c) according to the invention and, where appropriate, a blowing agent (d), a catalyst (e) and other auxiliaries and additives (f), preparing a reaction mixture and completing the reaction.

[0048] The present invention is therefore directed to a process for the preparation of a polyurethane comprising the reaction of at least one isocyanate (a), at least one polyol (b), and at least one phosphorus-containing polyol as disclosed above or obtainable or obtained according to the process disclosed above.

[0049] The polyisocyanate component (a) used to prepare the polyurethanes of the invention includes all polyisocyanates known for preparing polyurethanes. These also include the aliphatic, cycloaliphatic and aromatic di- or polyfunctional isocyanates known from the prior art, and any desired mixtures thereof. Examples are diphenylmethane 2,2"-, 2,4"- and 4,4"-diisocyanate, mixtures of monomeric diphenylmethane diisocyanates and mixtures of diphenylmethane diisocyanate homologues with multiple rings (polymeric MDI), isophorone diisocyanate (IPDI) and its oligomers, tolylene 2,4- or 2,6-diisocyanate (TDI) and mixtures thereof, tetramethylene diisocyanate and its oligomers, hexamethylene diisocyanate (HDI) and its oligomers, naphthylene diisocyanate (NDI), and mixtures thereof.

[0050] It is preferred to use tolylene 2,4- and / or 2,6-diisocyanate (TDI) or mixtures thereof, monomeric diphenylmethane diisocyanate and / or diphenylmethane diisocyanate homologues with multiple rings (polymeric MDI) and mixtures thereof. Other possible isocyanates are listed by way of example in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapters 3.2 and 3.3.2.

[0051] The polyisocyanate component (a) may be used in the form of a polyisocyanate prepolymer, which may be obtained by reacting an excess of the above polyisocyanate (component (a-1)) with a polyol (component (a-2)) at, for example, 30 to 100°C, preferably about 80°C, to produce a prepolymer.

[0052] Polyol (a-2) is known to those skilled in the art and is described, for example, in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapter 3.1. Thus, for example, the polyol used may also include the polyol described below under (b). Here, in a specific embodiment, the polyisocyanate prepolymer may also include the phosphorus-containing polyol of the present invention, which contains at least one phosphorus-containing group.

[0053] Polyols that can be used are known for polyurethane production and include all compounds (b) having at least two reactive hydrogen atoms, for example those having a functionality of 2 to 8 and a molecular weight of 400 to 15 000. Thus, by way of example, it is possible to use polyols selected from the group of polyether polyols, polyester polyols, and mixtures thereof.

[0054] By way of example, polyetherols are prepared from epoxides such as propylene oxide and / or ethylene oxide or from tetrahydrofuran by using starting compounds containing active hydrogen, such as aliphatic alcohols, phenols, amines, carboxylic acids, water or compounds based on natural substances, such as sucrose, sorbitol or mannitol, together with the use of catalysts, whereby reference may be made, by way of example, to basic catalysts or double metal cyanide catalysts, as described in PCT / EP2005 / 010124, EP90444 or WO05 / 090440.

[0055] For example, polyesterols are prepared from aliphatic or aromatic dicarboxylic acids and from polyfunctional alcohols, from polythioether polyols, from polyesteramides, from polyacetals containing hydroxyl groups, and / or from aliphatic phosphorus-containing polyols containing hydroxyl groups, preferably in the presence of an esterification catalyst. Other possible polyols are described, for example, in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapter 3.1.

[0056] Polyol (b) also comprises chain extenders and crosslinkers, the molar mass of which is less than 400 g / mol, the term used here for molecules having two hydrogen atoms reactive towards isocyanates being chain extenders, while the term used here for molecules having more than two hydrogen atoms reactive towards isocyanates being crosslinkers. Although it is possible here to exclude chain extenders or crosslinkers, the addition of chain extenders or crosslinkers, or, if appropriate, mixtures thereof, has proven to be advantageous for improving mechanical properties, such as, for example, hardness.

[0057] When chain extenders and / or crosslinkers are used, it is possible to use chain extenders and / or crosslinkers known for the production of polyurethanes. These are preferably low molecular weight compounds with functional groups reactive towards isocyanates, examples being glycerol, trimethylolpropane, glycols and diamines. Other possible low molecular weight chain extenders and / or crosslinkers are described, for example, in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapters 3.2 and 3.3.2.

[0058] The phosphorus-containing polyol of the present invention containing at least one phosphorus-containing group is used as component (c), where the proportion of the phosphorus-containing polyol (c) containing at least one phosphorus-containing group (hereinafter also referred to as phosphorus-containing polyol (c)) is not limited and is mainly determined by the degree of flame retardancy to be achieved.

[0059] Furthermore, according to the present invention, it is possible to adapt the phosphorus-containing polyol to the polyol (b) used for preparing polyurethane, for example by selecting a suitable molecular weight.Therefore, it is possible to improve, for example, the mechanical properties of the polyurethane prepared.According to the present invention, it is also possible to use a mixture of two or more different phosphorus-containing polyols.

[0060] The proportion of phosphorus-containing polyol here can vary, for example, from 0.1 to 50% by weight, preferably from 1 to 40% by weight and particularly preferably from 2 to 30% by weight, in each case based on the total weight of components (a) to (e), whereby the phosphorus content in the finished polyurethane is preferably from 0.01 to 10% by weight, particularly preferably from 0.05 to 5% by weight and in particular from 0.1 to 5% by weight, in each case based on the total weight of the polyurethane.

[0061] Based on the total amount of polyol used, the ratio of phosphorus-containing polyol used can be adjusted. For example, for the preparation of flexible foam, the ratio of phosphorus-containing polyol based on the total amount of polyol is in the range of 1-30%, preferably in the range of 5-20%. For example, for the preparation of rigid foam, the ratio of phosphorus-containing polyol based on the total amount of polyol is in the range of 2-50%, preferably in the range of 10-40%.

[0062] According to a further embodiment, the present invention is directed to a process for the preparation of polyurethanes as disclosed above, wherein at least one phosphorus-containing polyol is used in an amount of 1-30% of the total amount of all polyols used, or in an amount of 2-50% of the total amount of all polyols used.

[0063] The reaction mixture of the present invention preferably also contains a blowing agent (d) if the polyurethane is intended to be in the form of a polyurethane foam. Here, it is possible to use any blowing agent known for producing polyurethanes. These may include chemical and / or physical blowing agents. These blowing agents are described by way of example in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapter 3.4.5. Here, the term “chemical blowing agent” is used for compounds which generate gaseous products via reaction with isocyanates. Examples of these blowing agents are water and carboxylic acids. Here, the term “physical blowing agent” is used for compounds which are dissolved or emulsified in the starting materials for polyurethane production and which evaporate under the conditions of polyurethane formation. By way of example, these are hydrocarbons, halogenated hydrocarbons, and perfluoroalkanes such as perfluorohexane, fluorochlorocarbons, and other compounds such as ethers, esters, ketones, acetals, and / or liquid carbon dioxide. The amount of blowing agent used here can be as desired, preferably such that the density of the resulting polyurethane foam is 10 to 1000 g / L, particularly preferably 20 to 800 g / L, in particular 25 to 200 g / L.

[0064] The catalyst (e) used may include any catalyst normally used for polyurethane production. These catalysts are described, for example, in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapter 3.4.1. Examples of those used here are organometallic compounds, preferably organotin compounds, for example tin salts of organic carboxylic acids, such as tin acetate, tin octanoate, tin ethylhexanoate, and tin laurate, and dialkyltin(IV) salts of organic carboxylic acids, such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and dioctyltin diacetate, or bismuth carboxylates, such as bismuth(III) neodecanoate, bismuth 2-ethylhexanoate, and bismuth octanoate, or mixtures. Other possible catalysts are basic amine catalysts. Examples of these are amidines such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine, N-methyl- and N-ethyl-N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylbutanediamine, N,N,N',N'-tetramethylhexanediamine, pentamethyldiethylenetriamine, tetramethyldiaminoethyl ether, bis(dimethylaminopropyl)urea, dimethylpiperazine, 1,2-dimethylimidazole, 1-aza-bicyclo[3.3.0]octane, and preferably 1,4-diazabicyclo[2.2.2]octane, and alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyl- and N-ethyl-diethanolamine, and dimethylethanolamine. The catalyst (e) used includes a mixture of metal catalysts and of basic amine catalysts.

[0065] Other catalysts which may be used, especially when a relatively large excess of polyisocyanate is used, are tris(dialkylaminoalkyl)-s-hexahydrotriazines, preferably tris(N,N-dimethylaminopropyl)-s-hexahydrotriazine, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, alkali metal hydroxides such as sodium hydroxide, and alkali metal alcoholates such as sodium methoxide, potassium isopropoxide, and alkali metal or ammonium salts of carboxylic acids such as potassium formate, or ammonium formate, or the corresponding acetates or octanoates.

[0066] Examples of concentrations of catalyst (e) that can be used are from 0.001 to 5% by weight, in particular from 0.05 to 2% by weight, in the form of catalyst or catalyst combination, based on the weight of component (b).

[0067] It is also possible to use auxiliaries and / or additives (f). Here, any auxiliaries and additives known for producing polyurethanes can be used. As examples, mention may be made of surface-active substances, foam stabilizers, cell regulators, release agents, fillers, dyes, pigments, flame retardants, hydrolysis stabilizers, as well as fungistatic and bacteriostatic substances. These substances are described, for example, in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapters 3.4.4 and 3.4.6 to 3.4.11.

[0068] When preparing the polyurethanes of the invention, the amounts of polyisocyanate (a), polyol (b), phosphorus-containing polyol (c) and, where appropriate, blowing agent (d) reacted are generally such that the equivalent ratio of the NCO groups of the polyisocyanate (a) to the total number of reactive hydrogen atoms in components (b), (c) and, where appropriate, (d) is 0.75 to 1.5:1, preferably 0.80 to 1.25:1. When the cellular plastic contains at least some isocyanurate groups, the equivalent ratio used of the NCO groups of the polyisocyanate (a) to the total number of reactive hydrogen atoms in components (b), (c) and, where appropriate, (d) is usually 1.5 to 20:1, preferably 1.5 to 8:1. Here, a ratio of 1:1 corresponds to an isocyanate index of 100.

[0069] When the polyurethane produced by the present invention is a thermoplastic polyurethane, a flexible foam, a semi-rigid foam, a rigid foam, or an integral foam, there are only a few quantitative and qualitative differences between the specific starting materials (a) to (f) used to produce the polyurethane of the present invention. Thus, for example, solid polyurethane does not use a blowing agent, and for thermoplastic polyurethane, the starting materials used are mainly strictly difunctional. For example, it is also possible to use the functionality and chain length of a relatively high molecular weight compound having at least two reactive hydrogen atoms to change the elasticity and hardness of the polyurethane of the present invention. The type of modification is known to those skilled in the art.

[0070] By way of example, starting materials for the preparation of solid polyurethanes are described in EP 0989146 or EP 1460094, starting materials for the preparation of flexible foams are described in PCT / EP2005 / 010124 and EP 1529792, starting materials for the preparation of semi-rigid foams are described in “Kunststoffhandbuch, Band 7, Polyurethane” [Plastics handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition, 1993, chapter 5.4, starting materials for the preparation of rigid foams are described in PCT / EP2005 / 010955, and starting materials for the preparation of integral foams are described in EP 364854, US Pat. No. 5,506,275, or EP 897402. In each case, a phosphorus-containing polyol (c) is also added to the starting materials described in the abovementioned documents.

[0071] In another embodiment of the present invention, the phosphorus-containing polyol (c) has OH groups. Here, the phosphorus-containing polyol (c) is preferably adapted in terms of functionality and OH value so that there is little impairment or actually improvement in the mechanical properties of the resulting polymer. At the same time, the change in the processing profile is minimized. This type of adaptation can be achieved, for example, in that the OH value and functionality of compound (c) are within the range of the OH value and functionality of the polyol used for polyurethane production.

[0072] When the phosphorus-containing polyol (c) has OH groups, the production of flexible polyurethane foams preferably uses as phosphorus-containing polyol (c) a compound having an OH value of 2 to 200 mg KOH / g, particularly preferably 10 to 180 mg KOH / g, in particular 20 to 100 mg KOH / g, preferably an OH functionality of 2 to 4, particularly preferably 2.1 to 3.8, in particular 2.5 to 3.5.

[0073] When the phosphorus-containing polyol (c) has OH groups, the production of rigid polyurethane foams preferably uses as phosphorus-containing polyol (c) a compound having an OH value of 2 to 800 mg KOH / g, particularly preferably 50 to 600 mg KOH / g, in particular 100 to 400 mg KOH / g, preferably an OH functionality of 2 to 8, particularly preferably 2 to 6.

[0074] If the phosphorus-containing polyol (c) has OH groups, then the production of the thermoplastic polyurethane (TPU) preferably uses as phosphorus-containing polyol (c) a compound having an OH value of 2 to 600 mg KOH / g, particularly preferably 10 to 400 mg KOH / g and in particular 20 to 200 mg KOH / g, preferably having an OH functionality of 1.8 to 2.2, particularly preferably 2.9 to 2.1 and in particular 2.0.

[0075] If polyisocyanurate foams are produced using a ratio of NCO groups of polyisocyanate (a) to the total number of reactive hydrogen atoms in compounds (b), (c) and, where appropriate, (d) and (f) of 1.5 to 20:1, the OH functionality of component (c) is preferably 2 to 3, preferably having an OH value of 20 to 800 mg KOH / g, particularly preferably 50 to 60 mg KOH / g and in particular 100 to 400 mg KOH / g.

[0076] In all cases, however, it is also possible to use any phosphorus-containing polyol (c).

[0077] Here, the phosphorus-containing polyol (c) containing at least one phosphorus-containing group is preferably soluble in the polyol (b), where "soluble" means that in a mixture of the polyol components (b) and (c) in a ratio corresponding to the amount subsequently used to prepare a polyurethane, no second phase visible to the naked eye is formed after standing at 50°C for 24 hours, whereby the solubility can be improved, for example, via functionalization of the component (c) or of the phosphorus-containing polyol of the invention, respectively, for example by using alkylene oxides.

[0078] The present invention is also directed to the use of the phosphorus-containing polyol disclosed above or obtained or obtained according to the method disclosed above as a flame retardant.Furthermore, the present invention is directed to the use of the phosphorus-containing polyol disclosed above or obtained or obtained according to the method disclosed above for the preparation of polyurethanes having improved flammability properties.

[0079] The present invention is also directed to a polyurethane obtained or obtained by the above disclosed method for preparing a polyurethane. According to a further embodiment, the present invention is directed to a polyurethane as disclosed above, wherein said polyurethane is a polyurethane foam.

[0080] The present invention includes the following embodiments, which include specific combinations of the embodiments as indicated by their respective interdependencies defined therein.

[0081] 1. At least one polyol and a polyol of general formula (I): [ka] [In the formula, X represents Cl, Br, I, alkoxy, or hydrogen; Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] with a phosphorus-containing compound.

[0082] 2. The phosphorus-containing polyol of embodiment 1, wherein the phosphorus is present in the form of a phosphate group or a phosphinate group.

[0083] 3. The phosphorus-containing polyol according to embodiment 1 or 2, wherein the phosphorus-containing polyol has an OH-functionality of 0 to 8.

[0084] 4. The phosphorus-containing polyol according to any one of embodiments 1 to 3, wherein the phosphorus-containing polyol has a phosphorus content of 3 to 12% by weight, based on the total weight of the phosphorus-containing polyol.

[0085] 5. The phosphorus-containing polyol according to any one of embodiments 1 to 4, wherein the phosphorus-containing polyol has a molecular weight of 100 to 700 g / mol.

[0086] 6. At least one polyol and a compound of general formula (I): [ka] [In the formula, X represents Cl, Br, I, alkoxy, or hydrogen; Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] with a phosphorus-containing compound.

[0087] 7. The method of embodiment 6, wherein the phosphorus is present in the form of a phosphate group or a phosphinate group.

[0088] 8. The method of any one of embodiments 6 to 7, wherein the phosphorus-containing polyol has an OH-functionality of 0 to 8.

[0089] 9. The method of any of embodiments 6-8, wherein the phosphorus-containing polyol has a phosphorus content of 3 to 12 wt. %, based on the total weight of the phosphorus-containing polyol.

[0090] 10. The method of any of embodiments 6-9, wherein the phosphorus-containing polyol has a molecular weight of 100 to 700 g / mol.

[0091] 11. Use of the phosphorus-containing polyol according to any one of embodiments 1 to 5, or obtained or obtained according to the method according to any one of embodiments 6 to 10, as a flame retardant.

[0092] 12. Use of the phosphorus-containing polyol according to any one of embodiments 1 to 5 or obtainable or obtained according to the method according to any one of embodiments 6 to 10 for the preparation of a polyurethane having improved flammability properties.

[0093] 13. A process for preparing a polyurethane comprising the reaction of at least one isocyanate (a), at least one polyol (b), and at least one phosphorus-containing polyol according to any of embodiments 1 to 5, or obtainable or obtained according to the process according to any of embodiments 6 to 10.

[0094] 14. The method of embodiment 13, wherein the at least one phosphorus-containing polyol is used in an amount of 1 to 30% of the total amount of all polyols used.

[0095] 15. A polyurethane obtainable or obtained by the method according to embodiment 13 or 14.

[0096] 16. The polyurethane of embodiment 15, wherein the polyurethane is a polyurethane foam. EXAMPLES

[0097] To explain the invention, an example is used.

[0098] 1. Synthesis of phosphorus-containing polyol In a 6 L mini plant reactor, polyol (ethoxylated glycerol (>1<6.5 mol EO); 787 g, 2.5 mol) was dissolved in methylene chloride (3 L) and triethylamine (323 g, 3.2 mol) under inert atmosphere (N2-inerted). Diphenyl chlorophosphate (839 g, 3.1 mol) was added in 45 min (addition rate: 1119 g / h). The reaction temperature did not exceed 33° C. during the addition of diphenyl chlorophosphate. After the addition was complete, the reaction mixture was stirred at reflux conditions (internal temperature: 42° C.) and then at room temperature for a further 12 h.

[0099] The reaction mixture was then extracted successively with water (1×1.5 L), NaOH (1×1.0 L, 5% w / w), and water (2×1.0 L), respectively. The aqueous phase was discarded. The resulting organic phase was dried over MgSO4 (1.5 kg) overnight and filtered using a glass filter frit (D3). The filter cake was washed with additional methylene chloride (0.5 L). The aqueous phases were combined and the methylene chloride was quantitatively removed by distillation in vacuum (final conditions: 700 Pa (7 mbar), 80° C.).

[0100] The product was isolated as a clear, colorless oil (1087 g).

[0101] OH number: 100mgKOH / g according to DIN53240; Acid number: <0.5 mg KOH / g according to DIN EN ISO 2114. Phosphorus content: 7.4% (elemental analysis).

[0102] 2. Polyurethane synthesis 2.1 Synthesis of flexible polyurethane foam Polyurethane foams were prepared by first mixing all the components except the metal catalyst and isocyanate as shown in Tables 1 and 2. The metal catalyst was then added, if appropriate, and similarly incorporated by stirring. The isocyanate was weighed out separately and then added to the polyol component. The mixture was mixed until the reaction started and then poured into a metal box lined with plastic film. The total batch weight in each case was 1800 g. The foams were allowed to complete their reaction overnight and then cut with a saw to prepare test specimens.

[0103] [Table 1]

[0104] The following compounds were used: Polyol 1: Glycerin based polyoxypropylene polyoxyethylene polyol; OH number: 35 mg KOH / g; Functionality: 2.7 Polyol 2: graft polyol based on styrene-acrylonitrile; solids content: 45%; polyoxypropyleneoxyethylene polyol based on glycerin; OH number: 20 mg KOH / g; functionality: 2.7 Catalytic system 1: Standard catalytic system consisting of a metal catalyst and an amine catalyst Catalytic system 2: Amine catalyst partially capped with formic acid Isocyanate 1: A mixture of toluene 2,4- and 2,6-diisocyanate P-Polyol 1: Condensation product of diphenyl chlorophosphate and polyol 3; OH value: 8 mg KOH / g; P content: 7.9% P-Polyol 2: Condensation product of diphenyl chlorophinate and polyol 4; OH value: 137 mg KOH / g; P content: 7.3% P-Polyol 3: Condensation product of diphenyl chlorophosphate and polyol 4; OH value: 112 mg KOH / g; P content: 7.3% TCPP: Tris(chloroisopropyl)phosphate, a commercially available halogen-containing flame retardant, P content 9.46% Polyol 3: Propoxylated glycerin; OH number: 400 mg KOH / g. Polyol 4: ethoxylated serine; OH value: 535 mg KOH / g.

[0105] The following methods were used to measure the properties:

[0106] Density (kg / m 3 ): DIN EN ISO845 Compressive strength (kPa): DIN EN ISO3386 Rebound resilience (%): DIN EN ISO8307 Air permeability (dm 3 / s):DIN EN ISO7231 Flame Retardant: California TB117A.

[0107] California TB117A is a vertical small scale burner test for flexible PU foam. The specimen dimensions are 30.5 x 7.5 x 1.3 cm. The foam is ignited with a 3.8 cm flame for 12 seconds.

[0108] The test is (a) The maximum average burn length of all test specimens is less than 15 cm. (b) The maximum burning length of each test specimen is less than 20 cm. (c) The average afterburn time is 5 seconds or less. (d) The individual afterburn time of each test specimen is 10 seconds or less. (e) The average afterglow time is 15 seconds or less. (f) Tests are performed before and after conditioning at 104°C for 24 hours. If so, the test is passed.

[0109] If the test is passed for all specimens or if one specimen fails and an additional five specimens pass, the specification is met. Table 1 shows that the halogen-free flexible polyurethane foams of the present invention exhibit excellent flame retardancy, similar to or better than that of the comparative foams prepared using commercial TCPPs with similar or higher phosphorus content.

[0110] It is also found that despite the presence of the flame retardant according to the invention, the mechanical properties of the foam are improved rather than impaired.

[0111] 2.2 Synthesis of rigid polyurethane foam Rigid polyurethane foams were prepared as summarized in Table 2.

[0112] The following formulations were used: 46.5 parts of polyester polyol based on terephthalic acid and DEG, OH value: 243 mg KOH / g 25 parts of propoxylated sorbitol, OH value: 495 mg KOH / g 6 parts polyethylene glycol, OH value: 190 20 parts flame retardant 2.5 parts stabilizer Niax L-6635 (obtained from Momentive) 0.7 parts potassium acetate 0.4-0.7 parts Niax A1 (obtained from Momentive) 1.3 to 1.6 parts water 7 parts n-pentane Lupranat M50 (polymeric MDI from BASF with an NCO content of 31.5%) in an amount giving an NCO-index of 190.

[0113] Polyol, stabilizer, flame retardant, catalyst and blowing agent are mixed and stirred. The isocyanate is then added with stirring and the whole mixture is foamed into a rigid polyurethane foam. By adjusting the amount of catalyst, the curing time is 45 seconds in each case. The density is adjusted to a constant 45 g / L via the amount of blowing agent.

[0114] [Table 2]

[0115] The following flame retardants were used: P-Polyol 4: Condensation product of diphenyl chlorophenate and Polyol 4; OH value: 127 mg KOH / g; P content: 6.9% P-Polyol 5: Condensation product of diphenyl chlorophenate and polyol 4; OH value: 75 mg KOH / g; P content: 7.9% DPK: diphenylcresyl phosphate

[0116] The tack free time is defined as the time from the start of stirring to the time when the foam, when in contact with the rod, is almost free of any tacky effect. The tack free time is an indicator for the effectiveness of the polymerization.

[0117] Bolt: 3, 4 and 5 minutes after mixing the components, a steel bolt with a spherical cap of 10 mm radius is pressed 10 mm into the formed foam by a tension-compression fatigue test device. The maximum force (N) required to achieve this is an indication of the degree of effectiveness of the foam. As an indication of the fragility of the foam, the time at which the surface of the foam shows a visible fracture zone in the bolt test is measured. The earlier the fracture zone appears, the more fragile the foam is.

[0118] The flaming test is carried out according to EN ISO 11925-2.

[0119] The compressive strength and the E-module were determined according to DIN 53421 / DIN EN ISO 604.

[0120] The examples in Table 2 demonstrate that the halogen-free rigid polyurethane foams according to the invention exhibit excellent flame protection properties similar or equal to those of the halogen-containing comparative foams. Additionally, improved mechanical properties and lower flame heights are observed.

[0121] 2.3 Synthesis of PIR rigid foam Polyisocyanurate rigid foams were prepared as summarized in Table 3.

[0122] The following formulations were used: 65 parts of polyester polyol based on phthalic anhydride and DEG, OH value: 215 mg KOH / g 8 parts polyethylene glycol, OH value: 190mgKOH / g 25 parts flame retardant 2 parts stabilizer Tegostab B8462 (obtained from Evonik) 0.7 parts potassium formate 1.4 to 1.6 parts Niax A1 (obtained from Momentive) 1.5 to 1.7 parts formic acid, 85% 9 parts n-pentane Lupranat M50 (polymeric MDI from BASF with an NCO content of 31.5%) in an amount giving an NCO-index of 330.

[0123] Polyol, stabilizer, flame retardant, catalyst and blowing agent are mixed and stirred. The isocyanate is then added with stirring and the whole mixture is foamed into a rigid polyurethane foam. By adjusting the amount of catalyst, the curing time is 45 seconds in each case. The density is adjusted to a constant 45 g / L via the amount of blowing agent.

[0124] [Table 3]

[0125] The following flame retardants were used: P-Polyol 6: Condensation product of diphenyl chlorophenate and polyol 4; OH value: 123 mg KOH / g; P content: 7.1% TEP: Triethyl phosphate

[0126] BKZ5-Test: In the flame test according to the Swiss norm BKZ / V, the flame height is measured in cm.

[0127] Flexural strength: Determined according to DIN 53423. Bending is performed in the direction of foam growth.

[0128] The examples in Table 3 demonstrate that halogen-free rigid polyurethane foams according to the present invention exhibit excellent flame protection combined with improved compressive and flexural strength.

Claims

1. At least one polyol and a polyol of general formula (I): [Formula 1] [In the formula, X represents Cl, Br, I, alkoxy, or hydrogen, Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] with a phosphorus-containing compound, The phosphorus-containing polyol has at least one general formula (II): [chemical 2] [In the formula, Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] containing a phosphorus-containing group of the formula the polyol is selected from the group consisting of polyether polyols made from epoxides; At least one of R1 and R2 represents C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, aryl, C6-C10-aryl-C1-C16-alkyl, or C1-C16-alkyl-C6-C10-aryl; the phosphorus-containing polyol has an OH-functionality of 2 to 4 and a molecular weight of 100 to 700 g / mol; and The phosphorus content of the phosphorus-containing polyol is 7 to 12 mass %, The phosphorus-containing polyol is halogen-free; The phosphorus-containing polyol is a flame retardant. Phosphorus-containing polyols.

2. 2. The phosphorus-containing polyol of claim 1, wherein the phosphorus is present in the form of a phosphate group or a phosphinate group.

3. 3. The phosphorus-containing polyol according to claim 1, wherein the phosphorus-containing polyol has a phosphorus content of 7 to 12% by weight, based on the total weight of the phosphorus-containing polyol.

4. At least one polyol and a polyol of general formula (I): [C3] [In the formula, X represents Cl, Br, I, alkoxy, or hydrogen, Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] with a phosphorus-containing compound, comprising the steps of: The phosphorus-containing polyol has at least one general formula (II): [C4] [In the formula, Y represents O or S; t is 0 or 1; R1 and R2 independently represent C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C1-C16-alkoxy, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, C3-C10-cycloalkoxy, aryl, aryloxy, C6-C10-aryl-C1-C16-alkyl, C6-C10-aryl-C1-C16-alkoxy, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryl, C1-C16-alkyl-C6-C10-aryloxy.] containing a phosphorus-containing group of the formula the polyol is selected from the group consisting of polyether polyols made from epoxides; At least one of R1 and R2 represents C1-C16-alkyl, C2-C16-alkenyl, C2-C16-alkynyl, C2-C16-alkenoxy, C2-C16-alkynoxy, C3-C10-cycloalkyl, aryl, C6-C10-aryl-C1-C16-alkyl, or C1-C16-alkyl-C6-C10-aryl; the phosphorus-containing polyol has an OH-functionality of 2 to 4 and a molecular weight of 100 to 700 g / mol; and The phosphorus content of the phosphorus-containing polyol is 7 to 12 mass %, The phosphorus-containing polyol is halogen-free; The phosphorus-containing polyol is a flame retardant. method.

5. Use of the phosphorus-containing polyol according to any one of claims 1 to 3 or obtainable or obtained according to the process according to claim 4 as a flame retardant.

6. Use of the phosphorus-containing polyol according to any one of claims 1 to 3 or obtainable or obtained according to the process according to claim 4 for the preparation of polyurethanes with improved flammability properties.

7. 5. A process for the preparation of a polyurethane comprising the reaction of at least one isocyanate (a), at least one polyol (b) and at least one phosphorus-containing polyol according to any one of claims 1 to 3 or obtainable or obtained according to the process according to claim 4.

8. The method of claim 7, wherein said at least one phosphorus-containing polyol is used in an amount of from 1 to 30% of the total amount of all polyols used.

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