Production of flame-retardant polyurethane foams

Abstract

The invention relates to a composition for producing PU foams, preferably rigid PU foams, comprising at least one halogen-free polyester polyol and at least one halogenated polyol, at least one physical blowing agent, at least one flame retardant selected from (a) the group of phosphoric acid esters, preferably TCPP, TEP and / or TCEP, in particular TCPP and / or TEP, and / or (b) the group of phosphonic acid esters, preferably DMMP and / or DMPP, red phosphorus, and at least one flame retardant selected from the group of phosphoric acid esters, preferably TCPP, TEP and / or TCEP, in particular TCPP and / or TEP, and / or (b) the group of phosphonic acid esters, preferably DMMP and / or DMPP. And at least one polyisocyanate component, wherein the composition has an index of at least 200.

Description

[0001] The present invention is in the field of polyurethanes, preferably polyurethane foams, especially rigid polyurethane foams. It particularly relates to the production of flame-retardant polyurethane foams, preferably flame-retardant rigid polyurethane foams, using a combination of synergistic active ingredients, as well as compositions for the production of such foams and also the use of these foams.

[0002] Polyurethane (PU) in the context of the present invention is particularly understood to mean the product that can be obtained by the reaction of polyisocyanate component and polyol component or compound with isocyanate reactive groups.Except polyurethane, other functional groups can also be formed in the reaction, such as isocyanate dimer, carbodiimide, diisocyanate trimer, allophanate, biuret, urea and / or uretonimine.Therefore, for purposes of the present invention, PU is not only understood to mean polyurethane, but also means polyisocyanurate, polyurea and the polyisocyanate reaction product containing isocyanate dimer, carbodiimide, allophanate, biuret and uretonimine groups.In the context of the present invention, polyurethane foam (PU foam) is understood to mean the foam obtained as the reaction product of polyisocyanate component and polyol component or compound with isocyanate reactive groups. Besides the polyurethanes of the same name, other functional groups can likewise form here, examples being allophanates, biuret, urea, carbodiimides, isocyanate dimers, diisocyanate trimers or uretonimines.

[0003] Rigid PU foam is an established technical term. The known basic difference between flexible foam and rigid foam is that flexible foam displays elastic properties, so deformation is reversible. In contrast, rigid foam deforms permanently.

[0004] A particularly important problem in connection with the provision of PU foams, in particular rigid PU foams, is the provision of PU foams having good flame retardant properties. For this reason, flame retardants are used. Flame retardants are substances known per se for limiting, slowing down or preventing the spread of fire. In the known prior art, for example in the Plastics Flammability Handbook, Carl Hanser Verlag, 3rd edition, 2004, corresponding flame retardants having flame retardant properties and suitable for PU foams are described.

[0005] Due to a large number of fire incidents, the global requirements for building materials in the construction industry, especially for insulation materials, have increased dramatically in recent years with regard to flame retardancy. This has led to the fact that conventional rigid polyurethane foams can no longer be used even in countries with particularly high requirements, such as Japan or South Korea, because they do not meet the current new standards. For example, according to KS F ISO 5660-1:2015-03, South Korea stipulates that no more than 8MJ / m2 The total heat release does not exceed 200kW / m 2 The heat release rate is very high, so the requirements for rigid polyurethane foam there are the most stringent in the world.

[0006] In order to improve the flame retardant properties of polyurethane foams, in particular rigid polyurethane foams, it is common practice to increase the amount of flame retardant used. However, the effect that can be achieved and the maximum possible amount of use are limited by the fact that the flame retardant has a negative impact on the overall properties of the foam, such as its mechanical strength and / or the processing and production of the polyurethane foam. For example, the use of triethyl phosphate (TEP), tris(2-chloroethyl) phosphate (TCEP) or tris(1-chloro-2-propyl) phosphate (TCPP) usually has a strong plasticizing effect, which reduces the mechanical load-bearing capacity and therefore limits the amount used. Other flame retardants, first of all those used as solids, can cause considerable problems in terms of dispersion in liquid starting materials and lead to an increase in viscosity, which makes processing significantly more difficult or even impossible. Since many flame retardants also have ecological and toxicological disadvantages, people try to minimize their use while meeting all requirements.

[0007] In this context, a specific object of the present invention is to be able to provide PU foams, in particular rigid PU foams, which meet the increased requirements for flame retardancy, preferably according to KSF ISO 5660-1:2015-03, i.e. preferably at 50 kW / m 2 The total heat release does not exceed 8 MJ / m at a heating rate of 1000 Nm and a test duration of 600 s. 2 And the heat release rate does not exceed 200kW / m 2 , but has only little effect, if any, on processing and foam properties.

[0008] In this respect, it has surprisingly been found that, in the context of the present invention, the objects can be achieved using a specific combination of compounds as claimed in claim 1 in a composition for producing PU foams, preferably rigid PU foams, in particular rigid PU foams having an index of more than 200. The processing and foam properties are affected only to a minor extent, if at all.

[0009] The above objects are achieved by the subject matter of the present invention. The subject matter of the present invention is a composition for producing PU foam, preferably rigid PU foam, comprising

[0010] at least one halogen-free polyester polyol and at least one halogenated polyol,

[0011] at least one physical blowing agent,

[0012] At least one flame retardant selected from the following

[0013] (a) the group of phosphoric acid esters, preferably tris(1-chloro-2-propyl) phosphate (TCPP), triethyl phosphate (TEP) and / or tris(2-chloroethyl) phosphate (TCEP), in particular TCPP and / or TEP,

[0014] and / or

[0015] (b) the group of phosphonates, preferably dimethyl methylphosphonate (DMMP) and / or dimethyl propylphosphonate (DMPP),

[0016] Red phosphorus,

[0017] and at least one polyisocyanate component, wherein the composition has an index of at least 200. The upper limit of the index may be, for example, preferably 1000, preferably 500.

[0018] The subject matter of the invention is associated with a wide range of advantages. For example, it enables the provision of PU foams, preferably rigid PU foams, which meet particularly high requirements in terms of flame retardancy, in particular as defined in KS F ISO 5660-1:2015-03. Advantageously, this is possible without adversely affecting the other properties of the foam, in particular its mechanical properties. In providing PU foams, preferably rigid PU foams, particularly fine-pored, homogeneous and low-defect foam structures are also made possible. Thus, the provision of corresponding PU foams with particularly good use properties is achieved. Overall, the invention enables simple processing in the context of foam production.

[0019] When the red phosphorus (CAS No.: 7723-14-0) used according to the invention is microencapsulated, this is a particularly preferred embodiment of the invention. The microencapsulation of red phosphorus is well known from the prior art. For example, a possible variant is described in EP 1 262 453 A2.

[0020] It is a particularly preferred embodiment of the present invention when the composition according to the invention additionally contains at least one smoke suppressant, which is preferably selected from the group consisting of antimony trioxide, zinc stannate, zinc hydroxystannate, zinc borate, calcium borate, zinc pyrophosphate, aluminum orthophosphate and aluminum phosphite, with antimony trioxide and / or zinc borate being most preferred.

[0021] For the purposes of the present invention, when a component or at least one component, such as a chemical compound, is selected from a group consisting of two or more components, such as two or more chemical compounds, this for the purposes of the present invention means that each individual component of the group of components mentioned can be selected, or a mixture from the group can be selected. Using the smoke suppressant mentioned above as an example, this means that for example zinc stannate or for example antimony trioxide, etc. can be selected, or for example antimony trioxide and zinc hydroxystannate or for example other mixtures can be selected.

[0022] The solid flame retardants used, such as red phosphorus or smoke suppressants, can be introduced into the reaction mixture, for example, via one of the two reaction components, ie via the polyol component or via the polyisocyanate component. In this case, introduction via the polyol component is preferred.

[0023] It is a particularly preferred embodiment of the present invention when in the composition of the present invention at least one halogenated polyol is selected from the group consisting of:

[0024] (i) brominated and / or chlorinated aliphatic or aromatic polyether diols and / or polyether triols, preferably brominated aliphatic or aromatic polyether diols and / or polyether triols,

[0025] and

[0026] (ii) a polyester polyol based on tetrabromophthalate, preferably compound 1

[0027]

[0028] Compound 1 (CAS 77098-07-8),

[0029] Among them, compound 1 is the most preferred.

[0030] This is a further particularly preferred embodiment of the present invention when the composition according to the invention contains compound 1 and TCPP and / or TEP and additionally antimony trioxide and / or zinc borate.

[0031] The composition according to the invention further preferably contains at least one catalyst, preferably at least one trimerization catalyst, in particular selected from the group consisting of ammonium salts and metal salts of 2-ethylhexanoic acid, formic acid, acetic acid, propionic acid, neodecanoic acid and neopentanoic acid. This also corresponds to another particularly preferred embodiment of the present invention.

[0032] At least one physical blowing agent is also preferably selected from the group consisting of dimethoxymethane, methyl formate, HFC-245fa, 1233zd, 1336mzz, cyclopentane, isopentane and n-pentane, particularly preferably selected from the group consisting of HFC-245fa, 1233zd, cyclopentane, isopentane and n-pentane. This also corresponds to another particularly preferred embodiment of the present invention.

[0033] It is likewise a particularly preferred embodiment of the invention when the composition according to the invention has the following specific features: based on 100 parts by weight of the total halogen-free polyol component, there are

[0034] 1 to 80 parts by weight, preferably 1.5 to 50 parts by weight, particularly preferably 2 to 40 parts by weight, of halogenated polyols,

[0035] a total amount of 2 to 60 parts by weight, preferably 5 to 50 parts by weight, particularly preferably 5 to 40 parts by weight, of a flame retardant selected from (a) the group of phosphoric esters, preferably TCPP, TEP and / or TCEP, and / or from (b) the group of phosphonic esters, preferably DMMP and / or DMPP,

[0036] a total amount of 1 to 45 parts by weight, preferably 2 to 35 parts by weight, particularly preferably 5 to 30 parts by weight, of red phosphorus,

[0037] A total amount of 0 to 40 parts by weight, preferably 1 to 35 parts by weight, particularly preferably 1.5 to 25 parts by weight, of an optionally present smoke suppressant, preferably selected from the group consisting of antimony trioxide, zinc stannate, zinc hydroxystannate, zinc borate, calcium borate, zinc pyrophosphate, aluminum orthophosphate and aluminum phosphite.

[0038] It is another particularly preferred embodiment of the present invention when the composition according to the invention has the following specific features: based on 100 parts by weight of the total halogen-free polyol component, there is

[0039] 1 to 80 parts by weight, preferably 1.5 to 50 parts by weight, particularly preferably 2 to 40 parts by weight of compound 1,

[0040] a total amount of 2 to 60 parts by weight, preferably 5 to 50 parts by weight, particularly preferably 5 to 40 parts by weight of TCPP and / or TEP,

[0041] a total amount of 1 to 45 parts by weight, preferably 2 to 35 parts by weight, particularly preferably 5 to 30 parts by weight, of red phosphorus,

[0042] Antimony trioxide and / or zinc borate in a total amount of 1 to 40 parts by weight, preferably 1.5 to 35 parts by weight, particularly preferably 1.5 to 25 parts by weight.

[0043] In addition, the composition according to the invention particularly preferably additionally contains at least one foam stabilizer, preferably a foam stabilizer based on polyether siloxanes, in particular in an amount of 0.1 to 4 parts, based on 100 parts of the total polyol component. This corresponds to a particularly preferred embodiment of the present invention. Foam stabilizers, preferably foam stabilizers based on polyether siloxanes, which can be used for the production of PU foams are known per se. Suitable foam stabilizers are also described below.

[0044] It is a further particularly preferred embodiment of the present invention when the composition according to the invention comprises water and / or formic acid.

[0045] Of course, if desired, the composition according to the invention may also contain further optional additives, such as are commonly used and known from the prior art in connection with the production of polyurethanes, in particular PU foams.

[0046] The present invention further provides a process for producing PU foam, preferably rigid PU foam, using a foamable reaction mixture containing a composition according to the invention, in particular as defined in any one of claims 1 to 10 or as described above, especially in a preferred embodiment. The foamable reaction mixture may also preferably consist of a composition according to the invention.

[0047] In the context of the present invention, particularly preferred PU foam formulations, especially rigid PU foam formulations, have the composition given in Table 1:

[0048] Table 1: Composition of preferred rigid polyurethane foam formulations

[0049]

[0050] The present invention further provides a PU foam, preferably a rigid PU foam, which is produced by the above-described method according to the invention, in particular using the composition according to the invention.

[0051] When the PU foam according to the present invention, especially the rigid PU foam, has a mass of 5 to 900 kg / m 3 , preferably 5 to 350 kg / m 3 , especially 10 to 200 kg / m 3 This is a preferred embodiment of the present invention.

[0052] As mentioned above, the present invention further provides the use of the PU foam according to the invention, in particular the rigid PU foam, as an insulating material and / or building material, in particular in construction applications, in particular as a spray foam or in the refrigeration industry, or as pipe insulation for pipes.

[0053] Thus, the present invention has been described in detail and the skilled person is familiar with the production of PU, in particular PU foam, using at least one polyol component and at least one polyisocyanate component.

[0054] According to a particularly preferred embodiment of the present invention, the composition according to the invention contains in particular the following ingredients:

[0055] a) a polyol component comprising at least one halogen-free polyester polyol and at least one halogenated polyol,

[0056] b) Polyisocyanate component (at least one polyisocyanate and / or polyisocyanate prepolymer)

[0057] c) Catalysts which catalyze the reaction of isocyanate groups with OH groups, NH groups or other isocyanate-reactive groups and / or with one another

[0058] d) optional foam stabilizer

[0059] e) Foaming agent

[0060] f) Flame retardant

[0061] g) Optionally, other additives.

[0062] The polyol component (a) used may be one or more polyols having OH groups, SH groups, NH groups and / or NH 2 The polyol component comprises at least one organic compound having at least two isocyanate-reactive groups selected from OH groups, SH groups, NH groups and / or NH 2 Groups, especially OH groups.

[0063] Non-integer functionalities, i.e., for example, 1.8, may result from the mixing of at least one compound having a relatively high functionality (e.g., greater than or equal to 2) with at least one compound having a functionality of, for example, 1. This may occur in particular when polyisocyanate components (b) having a functionality of greater than 2 or additional crosslinkers are used as optionally present additives (g).

[0064] Suitable compounds which can usually be used in the production of PU are known to the person skilled in the art and are described, for example, in "Kunststoffhandbuch, Band 7, Polyurethane [Plastics Handbook, volume 7, Polyurethanes]", Carl Hanser Verlag, 3rd Edition 1993, Chapter 3.1. Compounds having an OH number in the range of 10 to 1200 mg KOH / g are usually used.

[0065] Particularly preferred compounds are all polyether polyols and polyester polyols which are usually used for producing polyurethane systems, in particular polyurethane foams.

[0066] The polyether polyols can be prepared by known methods, for example by polymerization of alkylene oxides, preferably ethylene oxide, 1,3-propylene oxide, 1,2- or 2,3-butylene oxide and / or tetrahydrofuran.

[0067] Preferred polyester polyols are esters based on aliphatic or aromatic polycarboxylic acids preferably having 2 to 12 carbon atoms. Examples of aliphatic carboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid and fumaric acid. Examples of aromatic carboxylic acids are phthalic acid, isophthalic acid, terephthalic acid and isomeric naphthalenedicarboxylic acids. Preferred polyester polyols can be obtained in particular by the condensation of these polycarboxylic acids with polyols, which are preferably diols or triols having 2 to 12 carbon atoms, particularly preferably having 2 to 6 carbon atoms, preferably trimethylolpropane, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and / or glycerol.

[0068] Furthermore, polyether polycarbonate polyols, polyols based on natural oils (natural oil based polyols, NOPs; described in WO 2005 / 033167, US 2006 / 0293400, WO 2006 / 094227, WO 2004 / 096882, US 2002 / 0103091, WO 2006 / 116456, EP 1678232), filled polyols, prepolymer based polyols and / or recycled polyols may be used.

[0069] Recycled polyols are polyols obtained by chemical recovery of polyurethanes, for example by solvolysis, such as glycolysis, hydrolysis, acidolysis or aminolysis. The use of recycled polyols constitutes a particularly preferred embodiment of the present invention.

[0070] In the context of the present invention, the polyol component must comprise at least one halogen-free polyester polyol and at least one halogenated polyol, as already described above.

[0071] The polyisocyanate component (b) used may generally be one or more polyisocyanates having two or more isocyanate groups. Suitable polyisocyanates for the purposes of the present invention are all organic isocyanates having two or more isocyanate groups, in particular the aliphatic, cycloaliphatic, arylaliphatic and preferably aromatic polyfunctional isocyanates known per se.

[0072] Examples which may be mentioned here are alkylene diisocyanates having 4 to 12 carbon atoms in the alkylene group, for example dodecane-1,12-diisocyanate, 2-ethyltetramethylene 1,4-diisocyanate, 2-methylpentamethylene 1,5-diisocyanate, tetramethylene 1,4-diisocyanate, pentamethylene diisocyanate (PDI) and preferably hexamethylene 1,6-diisocyanate (HMDI), cycloaliphatic diisocyanates such as cyclohexane 1,3- and 1,4-diisocyanate and the corresponding isomer mixtures, methylenedicyclohexyl 4,4'-diisocyanate and the corresponding isomer mixtures. -diisocyanates (H12MDI), isophorone diisocyanate (IPDI), methylcyclohexyl 2,4- and 2,6-diisocyanates and the corresponding isomer mixtures, and preferably aromatic diisocyanates and polyisocyanates such as toluene 2,4- and 2,6-diisocyanates (TDI) and the corresponding isomer mixtures, naphthalene diisocyanate, diethyltoluene diisocyanate, diphenylmethane 4,4'- or 2,2'- or 2,4'-diisocyanate (MDI) and polymethylene polyphenyl polyisocyanate (PMDI, "polymeric MDI"). The organic polyisocyanates can be used alone or in the form of mixtures thereof. It is likewise possible to use the corresponding "oligomers" of the diisocyanates, such as IPDI trimers based on diisocyanate trimers, biuret or isocyanate dimers. In addition, it is possible to use prepolymers based on the above-mentioned isocyanates. Mixtures of MDI and more highly condensed analogs having an average functionality of 2 to 4, which are known as polymeric MDI (also known as "crude MDI"), and the various isomers or isomer mixtures of TDI in pure form are particularly suitable. Isocyanates modified by incorporation of urethane, isocyanate dimer, diisocyanate trimer, allophanate and other groups (known as modified isocyanates) may also be used. Examples of particularly suitable isocyanates are also described in detail, for example, in EP 1712578, EP 1161474, WO 00 / 58383, US 2007 / 0072951, EP 1678232 and WO 2005 / 085310, which are incorporated herein by reference in their entirety.

[0073] The preferred ratio of the total polyisocyanate component and the total polyol component, expressed as the index of the formulation, i.e. the stoichiometric ratio of isocyanate groups to isocyanate-reactive groups (e.g. OH groups, NH groups) multiplied by 100, is in the range of 200 to 1000 and preferably 200 to 500. An index of 100 means a molar ratio of reactive groups of 1:1. According to the invention, the claimed composition has an index of at least 200.

[0074] Suitable catalysts (c) that can be used for producing polyurethanes, in particular PU foams, are known to those skilled in the art from the prior art. In the context of the present invention, usable compounds are all compounds that can catalyze the reaction of isocyanate groups with OH groups, NH groups or other isocyanate-reactive groups and / or the reaction of isocyanate groups with each other. Compounds that catalyze the reaction of isocyanate groups with each other, in particular trimerization reactions, are also referred to as trimerization catalysts by those skilled in the art and are described in, for example, EP 1 745 847 A1.

[0075] Conventional catalysts known from the prior art can be used here, including, for example, amines (cyclic, acyclic; monoamines, diamines, oligomers with one or more amino groups), ammonium compounds, organometallic compounds and / or metal salts, preferably those of tin, iron, bismuth, potassium and / or zinc. In particular, the catalyst used may be a mixture of two or more such compounds.

[0076] Foam stabilizers (d) and their use in the production of PU foams are known to those skilled in the art. The use of foam stabilizers is optional; preferably one or more foam stabilizers are used. The foam stabilizers that can be used are in particular surface-active compounds (surfactants). Preferably, foam stabilizers are used in the production of PU foams. They can be used to optimize the desired cell structure and foaming process. In the context of the present invention, in particular one or more known Si-containing compounds that assist foam generation (stabilization, cell regulation, cell opening, etc.) can be used. These compounds are well known from the prior art. Particularly preferably, at least one foam stabilizer based on polyether siloxane can be used. Corresponding siloxane structures that can be used in the context of the present invention are described, for example, in the following patent documents, although these documents describe the use only in conventional PU foams (e.g., as molded foams, mattresses, insulation materials, building foams, etc.): CN 103665385, CN 103657518, CN 103055759, CN 103044687, US 2008 / 0125503, US 2015 / 0057384, EP 1520870A1, EP 1211279, EP 0867464, EP 0867465, EP 0275563. In addition to surface-active silicon-containing compounds, Si-free surfactants can also be used. For example, EP 2295485 A1 describes the use of lecithin, and US 3746663 describes the use of vinylpyrrolidone-based structures as foam stabilizers for the production of rigid PU foams. Other Si-free foam stabilizers are described, for example, in EP 2511328 B1, DE 1020011007479 A1, DE 3724716 C1, EP 0734404, EP 1985642, DE 2244350 and US Pat. No. 5,236,961.

[0077] Blowing agents (e) and their use in the production of PU foams are known to those skilled in the art. The use of a blowing agent (e) or a combination of two or more blowing agents (e) depends in principle on the nature of the foaming method used, the nature of the system and the use of the PU foam obtained. According to the invention, at least one physical blowing agent is used. Chemical blowing agents can also be used in addition. Depending on the amount of blowing agent used, foams with high or low density are produced. For example, a foam with a density of 5 kg / m 3 Up to 900kg / m 3 , preferably 5 to 350 kg / m 3 , particularly preferably 8 to 200 kg / m 3 , especially 8 to 150 kg / m 3 of bubbles.

[0078] Physical blowing agents which can be used are one or more suitable compounds having a suitable boiling point and mixtures thereof. The physical blowing agents which can preferably be used have already been mentioned.

[0079] The chemical blowing agents used may be one or more compounds which react with NCO groups and release gases, for example water or formic acid, or compounds which release gases during the reaction due to the increase in temperature, for example sodium bicarbonate. It is a particularly preferred embodiment of the invention when, in addition to a physical blowing agent, the composition according to the invention contains water and / or formic acid as chemical blowing agents.

[0080] As flame retardant (f), as mentioned above, preference is given to at least one compound from the group of phosphoric esters, preferably TCPP, TEP and / or TCEP, and / or a compound from the group of phosphonic esters, preferably DMMP and / or DMPP, and additionally red phosphorus, preferably microencapsulated red phosphorus.

[0081] As optional additives (g), one or more substances known in the prior art and used for the production of polyurethanes, especially PU foams, such as crosslinking agents, chain extenders, stabilizers against oxidative degradation (called antioxidants), biocides, cell-refining additives, nucleating agents, cell openers, solid fillers, antistatic additives, thickeners, dyes, pigments, color pastes, fragrances and / or emulsifiers, etc. can be used.

[0082] The composition according to the invention may additionally optionally contain so-called smoke suppressants. Smoke suppressants that can preferably be used have already been mentioned. These advantageously have the specific feature that they do not have any direct effect on the flame retardancy when used alone, but in certain cases can significantly enhance the effect of other flame retardants and / or reduce the generation of smoke. Smoke suppressants are known to those skilled in the art and include, for example, antimony trioxide, zinc hydroxystannate, zinc stannate, zinc borate, calcium borate or antimony pentoxide. These are also described, for example, in Weil, Edward D. Levchik, Sergei V. (2016) Flame Retardants for Plastics and Textiles—Practical Applications (2nd Edition); Carl Hanser Verlag, chapter 4 or WO 2009109318 A1 or Su et al., Polymer degradation and stability, 2012; 97(11): 2128-2135 or Horrocks et al., Journal of Fire Sciences, 2010; 28(3): 217-248.

[0083] Unless something obviously contrary is apparent from the description, any preferred or particularly preferred embodiment of the invention may be combined with one or more other preferred or particularly preferred embodiments of the invention.

[0084] The method for producing PU foam according to the invention can be carried out by any known method, for example by manual mixing or preferably by means of a foaming machine. If the method is carried out using a foaming machine, a high pressure or low pressure machine can be used. The method according to the invention can be carried out intermittently or continuously and can use, for example, 1K, 1.5K or 2K systems as described in EP3717538 A1, US7776934B2, EP1400547 B1 or EP2780384B2.

[0085] The subject matter of the invention is described below by way of example, without any intention to restrict the invention to these exemplary embodiments, the scope of applicability of the invention being apparent from the entire description and the claims.

[0086] In the case of a range, general formula or class of specified compounds, these are intended to include not only the corresponding range or group of compounds explicitly mentioned, but also all subranges and subgroups of compounds that can be obtained by removing individual values ​​(ranges) or compounds. In the case of citing documents in the context of this specification, their entire contents, especially with respect to the subject matter forming the context in which the document is cited, are intended to form part of the disclosure of the present invention. Unless otherwise stated, percentages are by weight. In the case of stating average values, these are numerical average values ​​unless otherwise stated. Unless otherwise stated, in the case of stating parameters that have been determined by measurement, the measurements have been carried out at a temperature of 23°C and standard pressure. Example:

[0087] The formulations shown in Tables 2 and 3 were used for performance comparison. Comparative foaming operations were performed by manual mixing. To this end, the polyol component, catalyst, water, foam stabilizer, flame retardant, physical foaming agent and other optional additives were weighed into a beaker and mixed for 30 seconds (batch size 500 g) at 1000 rpm with the aid of a disk stirrer (6 cm in diameter). The beaker was reweighed to determine the amount of foaming agent evaporated during the mixing operation and to replenish it. pMDI ("polymeric MDI") was then added and the mixture was stirred at 3000 rpm for 5 seconds with the stirrer and immediately transferred to a 25 cm x 50 cm x 7 cm aluminum mold lined with polyethylene film and thermostated to 60 ° C. After 10 minutes, the foam was demoulded. After one day of foaming, the foam was analyzed. The surface and internal defects of the upper and lower sides were subjectively evaluated on a scale of 1 to 10, with 10 representing (idealized) defect-free foam and 1 representing very obviously defective foam.

[0088] The fire characteristics were determined using a cone calorimeter according to KS F ISO 5660-1:2015-03. For this purpose, 3 specimens (each measuring 10 x 10 x 5 cm) were cut from each foam and the total heat release (THR, MJ / m 2 ), peak heat release rate within 600 seconds (PHRR, kW / m 2 ), mass loss during the burning time (%) and burning time (s), more precisely, the time between the ignition and extinction of the flame. The heating rate is 50 kW / m 2 The arithmetic mean is determined by the values ​​of 3 samples. When THR < 8 MJ / m 2 and PHRR<200kW / m 2 The test is considered to have passed when . The results are shown in Tables 4 and 5.

[0089] Table 2: Rigid PU foam formulation (composition by weight)

[0090]

[0091] Table 3: Rigid PU foam formulation (composition by weight)

[0092]

[0093] *Diethylene glycol phthalic anhydride based polyester polyol with a hydroxyl value of 315 mg KOH / g

[0094] **Foam stabilizer based on polyether siloxane from Evonik Operations GmbH

[0095] ***Amine catalyst from Evonik Operations GmbH

[0096] ****Trimerization catalyst from Evonik Operations GmbH

[0097] *****Brominated aliphatic polyether triol having a hydroxyl value of 330 mg KOH / g and 31.5 wt% bromine

[0098] Table 4: Physical properties and fire characteristics

[0099] Preparation 1 2 3 4 5 6 7 8 9 10 11 <![CDATA[Density (kg / m 3 )]]> 39.7 38.4 38.1 40.6 41.2 39.1 40.8 40.6 40.5 41.2 39.8 upper side 6.5 6.0 6.5 6.0 6.0 6.0 5.5 6.5 6.0 6.0 6.0 Lower side 6.0 5.5 5.5 5.5 5.0 5.5 5.5 5.5 5.0 5.5 5.5 Internal defects 7.0 7.0 7.0 6.5 6.5 6.5 6.0 6.5 6.5 6.0 6.5 <![CDATA[THR(MJ / m 2 )]]> >8.0 >8.0 >8.0 >8.0 >8.0 6.3 4.9 6.1 4.2 4.5 4.9 <![CDATA[PHHR(kW / m 2 )]]> 56.7 57.0 60.5 52.1 55.2 31.5 24.8 26.1 22.5 24.2 27.1 Mass loss (%) 40.9 35.1 39.7 18.1 19.4 6.6 3.2 5.1 3.8 4.9 6.1 Burning time(s) 89 52 67 34 38 13 7 14 9 9 12

[0100] Table 5: Physical properties and fire characteristics

[0101] Preparation 12 13 14 15 16 17 18 19 20 21 <![CDATA[Density (kg / m 3 )]]> 39.2 40.2 40.0 40.7 38.4 39.3 44.1 46.0 41.5 41.7 upper side 5.5 5.5 6.5 6.0 6.0 6.0 6.5 6.5 2.0 2.0 Lower side 5.5 5.0 6.0 6.0 5.5 5.5 5.0 5.0 2.0 2.0 Internal defects 6.5 6.5 7.0 7.0 6.5 6.5 7.0 7.0 2.0 2.0 <![CDATA[THR(MJ / m 2 )]]> 6.2 5.4 6.4 5.5 6.4 4.8 7.8 7.6 - - <![CDATA[PHHR(kW / m 2 )]]> 42.0 35.9 32.1 26.9 34.1 31.0 74.4 68.5 - - Mass loss (%) 10.1 7.9 9.1 9.2 7.9 7.6 25.0 22.1 - - Burning time(s) 21 13 21 18 15 15 88 80 - -

[0102] The results show that the foams based on the composition according to the invention meet the flame retardancy requirements compared to the selected reference material not according to the invention and that the relevant foam properties are less affected, if at all, by the use of the composition according to the invention. The significantly reduced mass loss and the shorter burning time of the composition according to the invention are additionally indicators of significantly reduced smoke production, since less material enters the gas phase. Tests 20 and 21 produced very coarse, unusable foams, and therefore it was not possible to carry out the combustion test.

Claims

1. A composition for producing PU foam, preferably rigid PU foam, comprising - at least one halogen-free polyester polyol and at least one halogenated polyol, - at least one physical blowing agent, - At least one flame retardant selected from the following (a) the group of phosphoric acid esters, preferably tris(1-chloro-2-propyl) phosphate, triethyl phosphate and / or tris(2-chloroethyl) phosphate, in particular tris(1-chloro-2-propyl) phosphate and / or triethyl phosphate, and / or (b) the group of phosphonates, preferably dimethyl methylphosphonate and / or dimethyl propylphosphonate, - red phosphorus, and at least one polyisocyanate component, wherein the composition has an index of at least 200.

2. The composition according to claim 1, characterized in that It additionally contains at least one smoke suppressant, which is preferably selected from the group consisting of antimony trioxide, zinc stannate, zinc hydroxystannate, zinc borate, calcium borate, zinc pyrophosphate, aluminum orthophosphate and aluminum phosphite, with antimony trioxide and / or zinc borate being most preferred.

3. The composition according to any one of claims 1 and 2, characterized in that The at least one halogenated polyol is selected from the group consisting of: (i) brominated and / or chlorinated aliphatic or aromatic polyether diols and / or polyether triols, preferably brominated aliphatic or aromatic polyether diols and / or polyether triols, and (ii) a polyester polyol based on tetrabromophthalate, preferably compound 1 Compound 1 (CAS 77098-07-8), Among them, compound 1 is the most preferred.

4. A composition according to any one of the preceding claims, characterized in that It contains compound 1 and tri(1-chloro-2-propyl) phosphate and / or triethyl phosphate, and further contains antimony trioxide and / or zinc borate.

5. The composition according to any one of claims 1 to 4, characterized in that It contains at least one catalyst, preferably at least one trimerization catalyst, in particular selected from the group consisting of ammonium and metal salts of 2-ethylhexanoic acid, formic acid, acetic acid, propionic acid, neodecanoic acid and pivalic acid.

6. The composition according to any one of claims 1 to 5, characterized in that The at least one physical blowing agent is selected from the group consisting of dimethoxymethane, methyl formate, HFC-245fa, 1233zd, 1336mzz, cyclopentane, isopentane and n-pentane, and is particularly preferably selected from the group consisting of HFC-245fa, 1233zd, cyclopentane, isopentane and n-pentane.

7. The composition according to any one of claims 1 to 6, characterized in that Based on 100 parts by weight of the total halogen-free polyol component, there is - a total amount of 1 to 80 parts by weight, preferably 1.5 to 50 parts by weight, particularly preferably 2 to 40 parts by weight, of halogenated polyols, a total amount of 2 to 60 parts by weight, preferably 5 to 50 parts by weight, particularly preferably 5 to 40 parts by weight, of flame retardants selected from the group of (a) phosphoric acid esters, preferably tris(1-chloro-2-propyl) phosphate, triethyl phosphate and / or tris(2-chloroethyl) phosphate, and / or from the group of (b) phosphonic acid esters, preferably dimethyl methylphosphonate and / or dimethyl propylphosphonate, a total amount of 1 to 45 parts by weight, preferably 2 to 35 parts by weight, particularly preferably 5 to 30 parts by weight, of red phosphorus, The optional smoke suppressants are preferably selected from the group consisting of antimony trioxide, zinc stannate, zinc hydroxystannate, zinc borate, calcium borate, zinc pyrophosphate, aluminum orthophosphate and aluminum phosphite in a total amount of 0 to 40 parts by weight, preferably 1 to 35 parts by weight, particularly preferably 1.5 to 25 parts by weight.

8. A composition according to any one of the preceding claims, characterized in that Based on 100 parts by weight of the total halogen-free polyol component, there is - a total amount of 1 to 80 parts by weight, preferably 1.5 to 50 parts by weight, particularly preferably 2 to 40 parts by weight of compound 1, - tris(1-chloro-2-propyl) phosphate and / or triethyl phosphate in a total amount of 2 to 60 parts by weight, preferably 5 to 50 parts by weight, particularly preferably 5 to 40 parts by weight, a total amount of 1 to 45 parts by weight, preferably 2 to 35 parts by weight, particularly preferably 5 to 30 parts by weight, of red phosphorus, Antimony trioxide and / or zinc borate in a total amount of 1 to 40 parts by weight, preferably 1.5 to 35 parts by weight, particularly preferably 1.5 to 25 parts by weight.

9. The composition according to any one of claims 1 to 8, characterized in that It contains at least one foam stabilizer, preferably a foam stabilizer based on polyether siloxane, especially in an amount of 0.1 to 4 parts, based on 100 parts of the total polyol component.

10. The composition according to any one of claims 1 to 9, characterized in that It contains water and / or formic acid.

11. Process for producing PU foams, preferably rigid PU foams, using a foamable reaction mixture containing a composition as defined in any one of claims 1 to 10.

12. PU foam, preferably rigid PU foam, produced by the process according to claim 11.

13. Use of a PU foam, preferably a rigid PU foam, according to claim 12 as an insulating material and / or as a building material, in particular in construction applications, in particular as a spray foam or in the refrigeration industry, or as pipe insulation for pipes.

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