Stabilisers for polyurethane foams containing solid matter

Abstract

The invention relates to a composition for the production of polyurethane foam, comprising (A) a polyol component, (B) a polyisocyanate component, (C) at least one catalyst which catalyses the isocyanate-polyol, isocyanate-water and / or isocyanate trimerisation reactions, (D) at least one foam stabiliser, (E) at least one chemical and / or physical blowing agent, (F) at least one solid, wherein the at least one foam stabiliser is selected from the group of polyethersiloxanes of the general average composition according to formula 1: MaMb 1DcDd1.

Description

[0001] Stabilizers for polyurethane foams containing solid

[0002] The present invention lies in the field of polyurethanes, preferably polyurethane foams. In particular, it relates to a composition for producing polyurethane foam, preferably rigid polyurethane foam, comprising, among other things, solids and certain polyether siloxanes, as well as to a process for producing polyurethane foams, preferably rigid polyurethane foams, using solids, such as, in particular, powdered waste plastics, and certain polyether siloxanes. Furthermore, it relates to the resulting PU foams and their use.

[0003] The terms polyurethane and polyurethane foam are established technical terms and have long been known to those skilled in the art. For the purposes of the present invention, polyurethane (PU) is understood in particular to mean a product obtainable by reacting a polyisocyanate component with a polyol component. In addition to the polyurethane, other functional groups, such as uretdiones, carbodiimides, isocyanurates, allophanates, biurets, ureas, and / or uretimines, can also be formed. Therefore, polyurethane (PU) for the purposes of the present invention includes both polyurethanes and polyisocyanurates, polyureas, and polyisocyanate reaction products containing uretdione, carbodiimide, allophanate, biuret, and / or uretimine groups.Accordingly, polyurethane foam (PU foam) in the context of the present invention refers to a foam obtained as a reaction product of a polyisocyanate component and a polyol component. In addition to the eponymous polyurethane, other functional groups such as allophanates, biurets, ureas, carbodiimides, uretdiones, isocyanurates, and / or uretimines can also be formed.

[0004] Foams and PU foams are well known. Rigid polyurethane foam (rigid PU foam) is a well-established technical term. The known and fundamental difference between flexible and rigid foam is that flexible foam exhibits elastic behavior and, consequently, deformation is reversible. Rigid foam, on the other hand, is permanently deformed. Further information on rigid polyurethane foams can be found in "Kunststoffhandbuch, Volume 7, Polyurethane," Carl Hanser Verlag, 3rd edition 1993, Chapter 6. The terms "foam" and "foam" are used synonymously for the purposes of this invention. This also applies to related terms such as rigid foam or rigid foam, PU foam or PU foam, etc.

[0005] When it comes to producing PU foams, especially rigid PU foams, it is particularly important to produce them cost-effectively and to improve their properties. However, the liquid components typically used to produce polyurethane foam often reach their limits in this regard. Therefore, solids can be used to further improve, for example, flame resistance or thermal insulation properties. Another concern is to produce PU foams, especially rigid PU foams, in a particularly sustainable manner, e.g., through the use of bio-based and / or recycled solids. In the known prior art, such as in DE 19633891 A1, DE 4416749 A1, CN 107722601 A, WO 2021 116511 A1, ES 2526724 A1, JP 2020070410 A, EP 0 665 251 A2, Zhang, B., Feng, Z., Han, X. et al., J. Polym. Res.28, 407 (2021) or in Yang, Chunzhuang & Shao, Shuiyu, Frontiers in Materials 8, 712809m (2021) or in Zhu H, Xu S., ACS Omega, Apr 22;5 (17) 9658-9667 (2020) or in Heng Zhu and Shiai Xu ACS Omega 2020 5 (17), 9658-9667 or in Lu, W., Zeng, Z., He, Z., Liang, Y., Sun, Y., Song, S., Wang, L., Liu, R., J. Appl. Polym. Sci. 2022, e53546, corresponding solids are described which are suitable for use in PU, preferably in PU foam. For example, ground solids from used mattresses, PU-based insulation boards, PU insulation materials from refrigerators, other plastic-based waste streams, or bio-based materials such as lignin can be used to produce PU foams more sustainably. Solid flame retardants such as ammonium polyphosphate, red phosphorus, or melamine can be used to improve flame resistance.

[0006] The use of solids poses significant problems with regard to dispersion in the liquid starting materials and during processing. These include sedimentation, difficult redispersion after sedimentation, the resulting inhomogeneous distribution of solids in the PU foam, and, above all, the resulting inhomogeneous property profile of the polyurethane foams produced in this way.

[0007] In the production of polyurethane foams, especially corresponding rigid polyurethane foams, cell-stabilizing or foam-stabilizing additives (so-called foam stabilizers) are commonly used. These are intended to ensure a fine-cell, uniform, and low-interference foam structure and thus significantly positively influence the performance properties, such as the thermal insulation capacity of the rigid foam. Surfactants based on polyether-modified siloxanes are particularly effective in this regard and are therefore the preferred type of foam stabilizer. These so-called polyethersiloxane foam stabilizers (PES) are sufficiently known from the prior art and are described in detail, for example, in CN 103665385, CN 103657518, CN 103055759, CN 103044687, US 2008 / 0125503, US 2015 / 0057384, EP 1520870 A1, EP 1211279, EP 0867464, EP 0867465 and EP 0275563.

[0008] Against this background, the specific object of the present invention was to enable the provision of polyurethane foams, in particular rigid polyurethane foams, which contain solids and thereby overcome the above-mentioned problems of sedimentation, difficult redispersion after sedimentation, and inhomogeneous distribution in the material. This object is achieved by the subject matter of the invention. The subject matter of the invention is a composition for producing polyurethane foam, preferably rigid polyurethane foam, comprising

[0009] (A) a polyol component,

[0010] (B) a polyisocyanate component,

[0011] (C) at least one catalyst which catalyzes the isocyanate-polyol and / or isocyanate-water and / or isocyanate trimerization reactions,

[0012] (D) at least one foam stabilizer,

[0013] (E) at least one chemical and / or physical blowing agent,

[0014] (F) at least one solid, wherein the at least one foam stabilizer is selected from the group of polyether siloxanes of the general average composition according to formula 1,

[0015] MaMb 1 DcDd 1 (Formula 1) with

[0016] RR

[0017] M — R- Si- Oj / 2 M 1 — R 1 -Si-O 1 / 2

[0018] RR

[0019] RR

[0020] D = Oi / 2 _ Si _ Oi / 2 D 1 = Oi / 2 _ Si _ Oi / 2

[0021] RR 1a = 0 to 2, particularly preferably 1.5 to 2, b = 0 to 2, particularly preferably 0 to 0.5, c = 8 to 150, preferably 18 to 100, particularly preferably 18 to 70, d = 0 to 20, preferably 1 to 16, particularly preferably 1 to 13, where a + b = 2, and for b = 0, d > 1 and for d = 0, b = 1.5 to 2,

[0022] R = each independently of one another identical or different alkyl radicals having 1 to 16 carbon atoms, identical or different aryl radicals having 6 to 16 carbon atoms, H or -OR 2 , preferably methyl, ethyl, phenyl or H, particularly preferably methyl,

[0023] R 2 = each independently of one another, identical or different alkyl radicals having 1 to 16 carbon atoms, identical or different aryl radicals having 6 to 16 carbon atoms or H, R 1= each independently of one another identical or different polyether residues, preferably identical or different polyether residues with a general average composition according to formula 2,

[0024] (Formula 2)

[0025] R 3 = each independently of one another identical or different divalent alkyl radicals having 2 to 15 carbon atoms, preferably identical or different divalent alkyl radicals having 3-6 carbon atoms, particularly preferably -(CH2)3-,

[0026] R 4 = each independently of one another, identical or different alkyl radicals having 1 to 18 carbon atoms, which optionally have ether functions, or identical or different aryl radicals having 6 to 18 carbon atoms, which optionally have ether functions, or H, preferably H, ethyl or benzyl,

[0027] R 5 = each independently of one another identical or different residues selected from the group consisting of: R2 and C(O)R 2 , where methyl, butyl, H or C(O)Me are preferred, e = 0 to 100, preferably 0 to 80, particularly preferably 0 to 50, f = 0 to 100, preferably 0 to 80, particularly preferably 0 to 50, g = 0 to 100, preferably 0 to 80, particularly preferably 0 to 50, h = 0 to 100, preferably 0 to 40, particularly preferably 0, where at least one of the repeat units e, f, g or h is > 0, where it is very particularly preferred if at least one of the polyether radicals R 1 corresponds to at least one of the following categories 1 or 2

[0028] Category 1 , based on formula 2: e = 8 to 16, f = g = h = O, or e + f + g = 15 to 34,

[0029] (f + g) / (e + f + g) > 0 to 0.25, particularly preferably 0.1 to 0.2, h = 0,

[0030] Category 2, based on formula 2: e + f + g = 7 to 15,

[0031] (f + g) / (e + f + g) > 0.15 to 0.8, h = 0, or e + f + g = 13 to 32,

[0032] (f + g) / (e + f + g) > 0.25 to 0.8, particularly preferably 0.3 to 0.4, h = 0 and wherein polyether siloxanes according to formula 1 are used in a total amount of 0.1 to 15 parts by weight, preferably 0.5 to 10 parts by weight, particularly preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total polyol component. The polyether siloxanes usable according to the invention, in particular as characterized in one of the patent claims, can be obtained by the customary routes known to the person skilled in the art, for example by the known reaction of allyl polyethers and SiH-functional siloxanes using Pt catalysts. This is demonstrated in the experimental section using several examples.

[0033] The subject matter according to the invention is associated with numerous advantages. It enables the provision of PU foams, preferably rigid PU foams with high solids contents. This is advantageously achieved without compromising the other properties of the material, in particular its mechanical properties. With regard to the provision of rigid PU foams, particularly fine-cell, uniform, and low-defect foam structures are also enabled. This makes it possible to provide corresponding polyurethane foams with particularly good performance properties and a homogeneous property profile. Overall, the invention enables simple processing of the solids during production. The solids can, for example, be introduced into the reaction mixture via one of the two reaction components (polyol component or polyisocyanate component). Introduction via the polyol component is preferred.Sedimentation problems during storage of the dispersion of reaction component and solid can be significantly reduced or even eliminated by the present invention. The invention also enables very good redispersibility of the solid in the event of sedimentation after very long storage, so that, for example, constant stirring or mixing during storage is no longer necessary. The invention also enables a more homogeneous distribution of the solid in the polyurethane foam, leading to a more uniform property profile.

[0034] It corresponds to a particularly preferred embodiment of the invention if the composition according to the invention contains at least one polyether siloxane according to formula (1), which contains at least two polyethers of the general formula (2), wherein at least one of these polyethers must satisfy category 1 and at least one of these polyethers must satisfy category 2 and the preferred ratio of polyethers of category 1 and polyethers of category 2 in the polyether siloxane in question corresponds to 10:90 to 90:10 wt.%, particularly preferably 20:80 to 80:20 wt.%, in particular 30:70 to 70:30 wt.%.

[0035] If the composition according to the invention contains at least two polyether siloxanes according to formula (1), wherein at least one of these polyether siloxanes contains at least one polyether of the general formula (2) which satisfies category 1 and at least one of these polyether siloxanes contains at least one polyether of the general formula (2) which satisfies category 2 and wherein the preferred ratio of polyether siloxanes of the formula (1) containing at least one polyether of category 1 and polyether siloxanes of the formula (1) containing at least one polyether of category 2 is 10:90 to 90:10 wt.%, particularly preferably 20:80 to 80:20 wt.%, in particular 30:70 to 70:30 wt.%, then a further particularly preferred embodiment of the invention is present.

[0036] In the context of the present invention, a solid is understood to mean in particular a substance which is in the solid state at 25 °C and 101,325 kPa.

[0037] A further particularly preferred embodiment of the invention is when the composition according to the invention is characterized in that the at least one solid is used in a total amount of 5 to 100 parts by weight, preferably 5 to 80 parts by weight, particularly preferably 10 to 50 parts by weight, based on 100 parts by weight of the total polyol component.

[0038] If a composition according to the invention is characterized in that the at least one solid is selected from the group consisting of

[0039] (a) solid flame retardants, preferably ammonium polyphosphate, melamine, melamine-coated ammonium polyphosphate, melamine microencapsulated ammonium polyphosphate, melamine-formaldehyde resin microencapsulated ammonium polyphosphate, melamine cyanurate, red phosphorus, zinc borate, melamine polyphosphate, expandable graphite and / or antimony trioxide,

[0040] (b) plastic powder, and

[0041] (c) calcium carbonate, graphite, graphene, lignin and / or lignocellulose, this is a further particularly preferred embodiment of the invention.

[0042] The at least one solid is preferably in powder form. Preferred particle sizes are specified below.

[0043] If the plastic powder usable according to the invention consists of at least one plastic selected from the group consisting of polyethylene, polypropylene, polyamide (such as in particular PA6, PA6.6, PA10, PA11 and / or PA12), polyesters (such as in particular polyethylene terephthalate, polybutylene terephthalate and / or poly-e-caprolactone), polystyrene, polyacrylate, polymethyl methacrylate, polycarbonate, styrene-acrylonitrile copolymers, polyethers, polylactic acid, polyurethane, polysulfones, polyethersulfone, polyetherimide and polyimide or mixtures thereof, wherein the plastic powder can particularly preferably be formed from waste plastics, then again a further particularly preferred embodiment of the invention is present. A waste plastic is in particular a plastic which

[0044] (i) results from production waste obtained during plastics production, such as cutting residues, sawing waste or material that does not pass quality control, and / or

[0045] (ii) results from plastics that have reached the end of their service life, such as plastics based on PU foams from used refrigerators, used insulation materials or insulation boards, used sealing foams, used mattresses, used furniture, used sound absorption materials, used packaging foams, foams from used vehicles, used packaging, pipes or other used plastic components and / or semi-finished plastic products.

[0046] Again, a further particularly preferred embodiment of the invention is present when the composition according to the invention contains, as a solid, one or more plastic powders made from waste plastics, preferably from recycled polyurethanes, particularly preferably from recycled polyurethane foams.

[0047] The terms "waste plastics" and "recycled plastics" are used synonymously within the meaning of this invention. The terms "recycled polyurethane" and "PU recyclate" are used synonymously within the meaning of this invention. A "recycled polyurethane" or "PU recyclate" is therefore a waste polyurethane, preferably in powder form, which in particular

[0048] (i) results from production waste obtained during PU production, such as cutting residues, sawing waste or material that does not pass quality control, and / or

[0049] (ii) results from polyurethanes that have reached the end of their life.

[0050] Recycled polyurethane foams are therefore waste polyurethane foams, preferably in powder form.

[0051] A further particularly preferred embodiment of the invention is when the composition according to the invention is characterized in that the solid is a powder with an average diameter of < 500 pm, preferably < 200 pm, particularly preferably < 80 pm. The average diameter of the particles is determined by laser diffraction spectroscopy in accordance with ISO 13320:2020. Data on the average diameter correspond to the volume-based median value, i.e., indicate the diameter of a volume-equivalent sphere, compared to which 50% of the particles are smaller and 50% of the particles are larger. When the composition according to the invention is used as a blowing agent

[0052] (i) hydrocarbons having 3, 4 or 5 carbon atoms, preferably cyclo-, iso- and / or n-pentane, and / or

[0053] (ii) hydrofluoroolefins and / or hydrohaloolefins, preferably 1234ze, 1234yf, 1224yd, 1233zd(E) and / or 1336mzz and necessarily water, then a further preferred embodiment of the invention is present.

[0054] A preferred PU foam formulation, in particular PU rigid foam formulation within the meaning of this invention has the composition stated in Table 1.

[0055] Table 1 : Composition of a preferred PU foam formulation

[0056] A further object of the present invention is a process for producing PU foam, preferably rigid polyurethane foam, based on a reaction mixture containing a composition as described above, in particular as defined in one of claims 1 to 9.

[0057] The process according to the invention for producing PU foam, preferably rigid polyurethane foam, can be carried out by all known methods, e.g. by hand mixing or preferably with the aid of foaming machines. If the process is carried out using foaming machines, high-pressure or low-pressure machines can be used. The process according to the invention can be carried out both batchwise and continuously, and e.g. 1K, 1.5K or 2K systems as described in EP 3717538 A1, US 7776934 B2, EP 1400547 B1 or EP 2780384 B2 can be used. For further preferred embodiments and configurations of the process according to the invention, reference is also made to the statements already made above in connection with the composition according to the invention.

[0058] Yet another subject of the present invention is a PU foam, in particular a PU rigid foam, produced according to the above-mentioned process according to the invention, in particular using a composition according to the invention.

[0059] If the PU foam according to the invention, in particular PU rigid foam, has a density of 5 to 900 kg / m 3 , preferably 5 to 350 kg / m 3 , especially 8 to 200 kg / m 3 This is a preferred embodiment of the invention.

[0060] A further object of the present invention relates to the use of PU foam according to the invention, in particular PU rigid foam, as an insulating material and / or as a construction material, in particular in construction applications, in particular in spray foam and / or 1- & 1.5-component canned foam or in the refrigeration sector, as a sound absorption material, as packaging foam, as wood imitation, as model foam, as a headliner for automobiles, as automobile interior paneling, as a sealing foam or pipe sheathing for pipes.

[0061] A preferred composition according to the invention contains the following components:

[0062] A) Polyol component

[0063] B) Polyisocyanate component

[0064] C) Catalyst that catalyzes the reactions isocyanate-polyol and / or isocyanate-water and / or isocyanate trimerization

[0065] D) Foam stabilizer

[0066] E) Propellant

[0067] F) Solid according to the invention

[0068] G) Optional additional additives, liquid flame retardants, etc.

[0069] The polyol component (A) consists of at least one polyol and optionally at least one organic compound containing at least two isocyanate-reactive groups, preferably selected from the group consisting of OH, NH, and NH2 groups. Polyols are organic compounds containing multiple hydroxyl groups (-OH).

[0070] If one of the aforementioned organic compounds of the polyol component contains at least two OH groups, then it is exclusively classified as a polyol for the purposes of the invention. This means that if an organic compound of the polyol component is considered both a polyol and an organic compound containing at least two isocyanate-reactive groups selected from the group consisting of OH, NH, and NH2 groups, it is exclusively classified as a polyol for the purposes of the invention.

[0071] Based on its total weight, the polyol component preferably contains at least 50 wt.% of polyols which contain only hydroxyl groups (-OH) as isocyanate-reactive groups.

[0072] Based on the total number of isocyanate-reactive groups in the polyol component, it is preferred that at least 50% of these are hydroxyl groups (-OH).

[0073] Corresponding compounds that can typically be used in the production of PU foams are known to those skilled in the art and are described, for example, in "Kunststoffhandbuch, Volume 7, Polyurethane," Carl Hanser Verlag, 3rd edition 1993, Chapter 3.1. Compounds with OH numbers in the range of 10 to 1200 mg KOH / g are typically used.

[0074] Particularly preferred compounds are all polyether polyols and / or polyester polyols commonly used for the production of polyurethane systems, in particular polyurethane foams. Polyether polyols can be obtained, for example, by reacting polyhydric alcohols or amines with alkylene oxides. Polyester polyols that are preferably used are usually based on esters of polybasic carboxylic acids (which can be either aliphatic, for example, adipic acid, or aromatic, for example, phthalic acid or terephthalic acid) with polyhydric alcohols (usually glycols).

[0075] In addition, polyether polycarbonate polyols, 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), filler polyols, prepolymer-based polyols and / or recycling polyols can be used.

[0076] Recycling polyols are polyols obtained from the chemical recycling of polyurethanes, for example, by solvolysis, such as glycolysis, hydrolysis, acidolysis, or aminolysis. The use of recycling polyols represents a particularly preferred embodiment of the invention.

[0077] The polyisocyanate component (B) consists of at least one polyisocyanate having two or more isocyanate groups. Suitable polyisocyanates for the purposes of this invention are all organic isocyanates having two or more isocyanate groups, in particular the known aliphatic, cycloaliphatic, arylaliphatic, and preferably aromatic polyfunctional isocyanates.

[0078] Examples which may be mentioned here are alkylene diisocyanates having 4 to 12 carbon atoms in the alkylene radical, such as 1,12-dodecane diisocyanate, 2-ethyl-tetramethylene-1,4-diisocyanate, 2-methyl-pentamethylene-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, 4,4'-methylenedicyclohexyl diisocyanate (H12MDI), isophorone diisocyanate (IPDI), 2,4- and 2,6-methylcyclohexyl diisocyanate and the corresponding isomer mixtures and preferably aromatic di- and polyisocyanates such as 2,4- and 2,6-Toluene diisocyanate (TDI) and the corresponding isomer mixtures, naphthylene diisocyanate, diethyltoluene diisocyanate, 4,4'- or 2,2'- or 2,4'-diphenylmethane diisocyanate (MDI) and polymethylene polyphenyl polyisocyanate (PMDI, “polymeric MDI”).The organic polyisocyanates can be used individually or in the form of mixtures. Corresponding "oligomers" of diisocyanates can also be used, such as the IPDI trimer based on isocyanurate, biuret, or urethdione. Furthermore, the use of prepolymers based on the above-mentioned isocyanates is possible. Particularly suitable is the mixture known as "polymeric MDI" (also called "crude MDI"), consisting of MDI and more highly condensed analogues with an average functionality of 2 to 4, as well as the various isomers of TDI in pure form or as a mixture of isomers. It is also possible to use isocyanates modified by the incorporation of urethane, uretdione, isocyanurate, allophanate, and other groups, so-called modified isocyanates. Examples of particularly suitable isocyanates include:in EP 1712578, EP 1161474, WO 00 / 58383, US 2007 / 0072951 , EP 1678232 and WO 2005 / 085310, which are incorporated herein by reference.

[0079] A preferred ratio of isocyanate groups and isocyanate-reactive groups, expressed as an index of the formulation (isocyanate index), ie as a stoichiometric ratio of isocyanate groups to isocyanate-reactive groups (e.g. OH groups, NH groups) multiplied by 100, is in the range from 10 to 1000, preferably 40 to 400. An index of 100 represents a molar ratio of the reactive groups of 1 to 1.

[0080] Suitable catalysts (C) for the production of polyurethanes, especially PU foams, are known to the person skilled in the art. For the purposes of the present invention, in particular, all compounds capable of catalyzing the reaction of isocyanate groups with OH, NH, or other isocyanate-reactive groups and / or the reaction of isocyanate groups with one another are suitable.

[0081] The usual catalysts known from the prior art can be used here, e.g. 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, mixtures of several such compounds can be used as catalysts. Suitable amounts used depend on the type of catalyst and can, for example, in the case of amine catalysts, preferably be in the range of 0.05 to 5 pphp (= parts by weight based on 100 parts by weight of polyol component) or, for example, in the case of potassium salts, preferably in the range of 0.1 to 10 pphp.

[0082] Foam stabilizers (D) and their use in the production of PU foams are known to the person skilled in the art as described above. According to the invention, at least one of the polyethersiloxane foam stabilizers according to the invention is used. In addition to the polyethersiloxane foam stabilizers according to the invention, further polyethersiloxane foam stabilizers as well as 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. Further 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 5236961.

[0083] Blowing agents (E) and their use in the production of PU foams are known to those skilled in the art. The use of blowing agents is optional; preferably, blowing agents are used. The use of one or a combination of several blowing agents depends fundamentally on the type of foaming process used, the type of system, and the application of the resulting PU foam. Both chemical and / or physical blowing agents or a combination of both can be used. Depending on the amount of blowing agent used, a foam with a high or low density is produced. For example, foams with densities of 5 kg / m 3 up to 900 kg / m 3 , preferably 5 to 350 kg / m 3 , particularly preferably 8 to 200 kg / m 3 , especially 8 to 150 kg / m 3 be manufactured.

[0084] As optional physical blowing agents, one or more of the corresponding compounds with suitable boiling points, such as hydrocarbons with 3, 4 or 5 carbon atoms, preferably cyclo-, iso- or n-pentane, fluorocarbons (HFC), preferably HFC 245fa, HFC 134a or HFC 365mfc, chlorofluorocarbons (HCFC), preferably HCFC 141b, hydrofluoroolefins (HFO) or hydrohaloolefins, preferably 1234ze, 1234yf, 1224yd, 1233zd(E) or 1336mzz, esters, preferably methyl formate, ketones, preferably acetone, ethers preferably dimethoxymethane, or chlorinated hydrocarbons, preferably dichloromethane or 1,2-dichloroethane and mixtures thereof can be used.

[0085] As optional chemical blowing agents, one or more compounds can be used that either react with NCO groups to release gases, such as water or formic acid, or release gases due to the temperature increase during the reaction, such as sodium bicarbonate. A particularly preferred embodiment is when the composition according to the invention contains water as a blowing agent in combination with hydrocarbons having 5 carbon atoms, HFO, hydrohaloolefins or HFC, or mixtures thereof.

[0086] The usable solids (F) have already been described above. The mean particle diameter is determined using laser diffraction spectroscopy in accordance with ISO 13320:2020. Data on the mean particle diameter correspond to the volume-based median value, i.e., the diameter of a volume-equivalent sphere, compared to which 50% of the particles are smaller and 50% of the particles are larger.

[0087] As optional further additives (G), one or more of the substances known from the prior art which are used in the production of polyurethanes, in particular PU foams, such as crosslinkers, chain extenders, stabilizers against oxidative degradation (so-called antioxidants), flame retardants, biocides, cell-refining additives, nucleating agents, cell openers, antistatic additives, thickeners, dyes, color pastes, fragrances and / or emulsifiers, etc.

[0088] As an optional flame retardant, the composition according to the invention may contain one or more of the known flame retardants suitable for the production of PU foams, such as halogen-containing or halogen-free organic phosphorus-containing compounds, such as triethyl phosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(2-chloroethyl) phosphate (TCEP), dimethyl methanephosphonate (DMMP) or dimethylpropanephosphonate (DMPP), or halogenated compounds. Mixtures of different flame retardants may also be used.

[0089] Unless otherwise apparent from this description, any preferred or particularly preferred embodiment of the invention may be combined with one or more of the other preferred or particularly preferred embodiments of the invention.

[0090] The subject matters according to the invention are described below by way of example, without the invention, the scope of which emerges from the entire description and the claims, being intended to be limited to these exemplary embodiments. If ranges, general formulas or classes of compounds are specified, these are intended to include not only the corresponding ranges or groups of compounds that are explicitly mentioned, but also all sub-ranges and sub-groups of compounds that can be obtained by removing individual values ​​(ranges) or compounds. If documents are cited within the scope of this description, their content, particularly with regard to the facts in connection with which the document was cited, is intended to be fully incorporated into the disclosure of the present invention. Percentages are, unless otherwise stated, percentages by weight.Unless otherwise stated, mean values ​​are numerical averages. Unless otherwise stated, parameters determined by measurement are stated at a temperature of 23 °C and atmospheric pressure.

[0091] Examples:

[0092] Synthesis of polyethersiloxane foam stabilizers (PES)

[0093] A xylene solution of the Karstedt catalyst (platinum(O)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (CAS 68478-92-2)) was used as the Pt catalyst for the preparation of the polyethersiloxanes. The Pt content of the solution was 2 wt%. The catalyst was purchased from Merck and used without further processing.

[0094] To synthesize the polyethersiloxanes, allyl polyether and SiH-functional siloxane according to the composition given in Table 2 were placed in a three-necked flask equipped with a precision glass stirrer and reflux condenser. The ratio of allyl polyether to SiH-functional siloxane was chosen such that 1.4 mol of double bonds from the allyl polyether were present per mol of SiH functions. The apparatus was inertized with nitrogen, and the mixture was heated to 80 °C. Subsequently, 10 ppm of Pt, based on the total weight, was added in the form of the Pt catalyst described above. An exothermic reaction began. The temperature was kept below 110 °C by cooling. The reaction mixture was then stirred at 100 °C for 3 h. Clear to slightly cloudy products were consistently obtained.

[0095] PES 14 and PES 15 were prepared by mixing the respective foam stabilizers in a weight ratio of 1:1.

[0096] The polyether siloxanes shown in Table 2 according to Formula 1 and Formula 2 were prepared and subjected to application-related tests. For PES 1 to 15, R = methyl, R 3 = -(CH2)3- and h = 0. PES 1 to 3 are considered non-inventive comparative examples.

[0097] Table 2: Composition of polyethersiloxane foam stabilizers (PES)

[0098] * non-inventive comparative example

[0099] Application example 1 : Polyurethane rigid foam (PUR)

[0100] The formulations shown in Table 3 were used for the application-related comparison. The comparative foamings were carried out using a hand-mixing method. Polyol, catalysts, water, foam stabilizer, solids, and blowing agent were weighed into a beaker and mixed using a 6 cm diameter plate stirrer at 1000 rpm for 30 seconds. The amount of blowing agent evaporated during the mixing process was determined by reweighing and then replenished. MDI was then added, and the reaction mixture was stirred using the described stirrer for 5 seconds at 3000 rpm. The mold was then immediately transferred to a 145 cm x 14 cm x 3.5 cm aluminum mold thermostatted to 45 °C, tilted at an angle of 10° (along the 145 cm side) and lined with polyethylene film.The foam formulation was applied to the lower side so that the expanding foam fills the mold in the pouring area and rises towards the higher side. The amount of foam formulation used was calculated so that it was approximately 10% higher than the minimum amount required for the mold filling. After 10 minutes, the foams were demolded. One day after foaming, the foams were analyzed. Surface and internal defects were assessed subjectively using a scale of 1 to 10, with 10 representing an (idealized) undisturbed foam and 1 representing extremely severely disturbed foam. The thermal conductivity (A-value in mW / mK) was measured on 2.5 cm thick panes using a Hesto Lambda Control device, model HLC X206, at an average temperature of 10 °C in accordance with the specifications of the EN12667:2001 standard.

[0101] Table 3: PUR formulation. Quantities in parts by weight.

[0102] *Daltolac® R 471 from Huntsman, OH number 470 mg KOH / g

[0103] **Amine catalysts from Evonik Operations GmbH

[0104] *** Used PU insulation boards ground using a pin mill (cryogenic grinding with liquid nitrogen, peripheral speed 120 m / s)

[0105] ****Polymeric MDI, 200 mPa s, 31.5% NCO, functionality 2.7.

[0106] Application example 2: Polyisocyanurate rigid foam (PIR)

[0107] The formulations shown in Table 4 were used for the application-related comparison. The comparative foamings were carried out using a hand-mixing method. Polyol, catalysts, water, foam stabilizer, solids, and blowing agent were weighed into a beaker and mixed with a 6 cm diameter plate stirrer for 30 seconds at 1000 rpm (batch size 500 g). The amount of blowing agent evaporated during the mixing process was determined by reweighing and then replenished. The MDI was then added, the reaction mixture was stirred with the described stirrer for 5 seconds at 3000 rpm, and immediately transferred to a 25 cm x 50 cm x 7 cm aluminum mold lined with polyethylene film and thermostatted to 60 °C.

[0108] After 10 minutes, the foams were demolded. One day after foaming, the foams were analyzed. Surface and internal defects were subjectively assessed on a scale of 1 to 10, with 10 representing an (idealized) undisturbed foam and 1 representing extremely severely disturbed foam. The thermal conductivity (A-value in mW / mK) was measured on 2.5 cm thick panes using a Hesto Lambda Control device, model HLC X206, at an average temperature of 10 °C in accordance with the specifications of standard EN 12667:2001.

[0109] Table 4: PIR formulation. Quantities in parts by weight.

[0110] * Stepanpol® PS 2412 from Stepan, OH number 240 mg KOH / g

[0111] **Amine catalyst from Evonik Operations GmbH

[0112] ***Trimerization catalyst from Evonik Operations GmbH

[0113] **** Used PU insulation boards ground using a pin mill (cryogenic grinding with liquid nitrogen, peripheral speed 120 m / s)

[0114] *****p0|ymeric MDI, 200 mPa*s, 31.5% NCO, functionality 2.7.

[0115] The results are summarized in Tables 5 to 14. For formulations C to E and H to J, the foam stabilizers selected were those that showed the most promising results in formulations B and G. Table 5: Foam properties for foams of formulation A

[0116] * non-inventive comparative example

[0117] Table 6: Foam properties for foams of formulation B

[0118] * non-inventive comparative example Table 7: Foam properties for foams of formulation C

[0119] * non-inventive comparative example Table 8: Foam properties for foams of formulation D Non-inventive comparative example Table 9: Foam properties for foams of formulation E

[0120] * non-inventive comparative example Table 10: Foam properties for foams of formulation F non-inventive comparative example

[0121] Table 11 : Foam properties for foams of formulation G

[0122] * non-inventive comparative example Table 12: Foam properties for foams of formulation H Non-inventive comparative example Table 13: Foam properties for foams of formulation I

[0123] * non-inventive comparative example Table 14: Foam properties for foams of formulation J

[0124] * non-inventive comparative example

[0125] The results show that the non-inventive polyethersiloxanes lead to a significantly poorer property profile when used as solids, in particular higher thermal conductivity and a poorer surface. However, the polyethersiloxanes according to the invention can significantly improve the property profile compared to non-inventive polyethersiloxanes. Application Example 3: Dispersibility

[0126] For the application-related comparison, the formulations shown in Table 15 were used. Polyol and polyethersiloxane were weighed (batch size 250 g) and mixed with a plate stirrer (6 cm diameter) at 1000 rpm for 30 s. The solid was then added while the plate stirrer continued running (2000 rpm) and mixed for a further 45 s. The formulations were then poured into glass containers, sealed, and the time until complete sedimentation was measured.

[0127] After upright storage for 14 days at room temperature, all samples were redispersed, and their redispersibility was assessed on a scale of 1 to 3. A grade of 1 indicates that the sample could be redispersed by manually shaking the glass container for 30 seconds. A grade of 2 indicates that the sample could not be redispersed by manually shaking the glass container, but could be redispersed by using an electric laboratory stirrer (500 rpm for 60 seconds). A grade of 3 was awarded to samples in which a very solid, compact sediment formed that could not be redispersed by either of the two methods mentioned.

[0128] Table 15: Formulation for testing the dispersing behavior

[0129] *Daltolac® R 471 from Huntsman, OH number 470 mg KOH / g

[0130] “ Stepanpol® PS 2412 from Stepan, OH number 240 mg KOH / g

[0131] *** Used PU insulation boards ground using a pin mill (cryogenic grinding with liquid nitrogen, peripheral speed 120 m / s)

[0132] The results are summarized in Tables 16 and 17: Table 16: Sedimentation stability

[0133] * Non-inventive comparative example ** Due to the lower density of the ground PU recyclate, it floats to the top instead of settling. Therefore, the time required for the solution below to become almost clear was specified.

[0134] Table 17: Redispersibility

[0135] * Comparative example not according to the invention ** The PU recyclate settles on the surface. By inserting the stirrer (for the evaluation

[0136] 2) the upper phase is already disturbed to such an extent that no information on redispersibility could be given.

[0137] In the cases investigated, an improvement in sedimentation stability and redispersibility was achieved compared to formulations without polyether siloxanes or compared to formulations without polyether siloxanes according to the invention.

[0138] In particular, the formation of a solid, compact sediment was avoided. The invention therefore enables very good redispersibility of the solid in the event of sedimentation after very long storage, so that, for example, constant stirring or mixing during long storage periods is no longer necessary.

Claims

Patent claims 1 . Composition for the production of polyurethane foam, preferably polyurethane Rigid foam, comprising (A) a polyol component, (B) a polyisocyanate component, (C) at least one catalyst which catalyzes the isocyanate-polyol and / or isocyanate-water and / or isocyanate trimerization reactions, (D) at least one foam stabilizer, (E) at least one chemical and / or physical blowing agent, (F) at least one solid, characterized in that the at least one foam stabilizer is selected from the group of polyether siloxanes of < an average composition according to Formula 1, MaMb 1 DcDd 1 (Formula 1) with RR M — R- Si- Oj / 2 M 1 = R 1 -Si-O 1 / 2 RR a = 0 to 2, particularly preferably 1.5 to 2, b = 0 to 2, particularly preferably 0 to 0.5, c = 8 to 150, preferably 18 to 100, particularly preferably 18 to 70, d = 0 to 20, preferably 1 to 16, particularly preferably 1 to 13, where a + b = 2, and for b = 0, d > 1 and for d = 0, b = 1.5 to 2, R = each independently of one another identical or different alkyl radicals having 1 to 16 carbon atoms, identical or different aryl radicals having 6 to 16 carbon atoms, H or -OR 2 , preferably methyl, ethyl, phenyl or H, particularly preferably methyl, R 2 = each independently of one another identical or different alkyl radicals having 1 to 16 carbon atoms, identical or different aryl radicals having 6 to 16 carbon atoms or H, R 1= each independently of one another identical or different polyether residues, preferably identical or different polyether residues with a general average composition according to formula 2, (Formula 2) R 3 = each independently of one another identical or different divalent alkyl radicals having 2 to 15 carbon atoms, preferably identical or different divalent alkyl radicals having 3 to 6 carbon atoms, particularly preferably -(CH2)3- R 4 = each independently of one another, identical or different alkyl radicals having 1 to 18 carbon atoms, which optionally have ether functions, or identical or different aryl radicals having 6 to 18 carbon atoms, which optionally have ether functions, or H, preferably H, ethyl or benzyl, R 5 = each independently identical or different residues selected from the group consisting of: R 2 and C(O)R 2, where methyl, butyl, H or C(O)Me are preferred, e = 0 to 100, preferably 0 to 80, particularly preferably 0 to 50, f = 0 to 100, preferably 0 to 80, particularly preferably 0 to 50, g = 0 to 100, preferably 0 to 80, particularly preferably 0 to 50, h = 0 to 100, preferably 0 to 40, particularly preferably 0, where at least one of the repeat units e, f, g or h is > 0, where it is very particularly preferred if at least one of the polyether radicals R 1 corresponds to at least one of the following categories 1 or 2 Category 1 , based on formula 2: e = 8 to 16, f = g = h = O, or e + f + g = 15 to 34, (f + g) / (e + f + g) > 0 to 0.25, particularly preferably 0.1 to 0.2, h = 0, Category 2, based on formula 2: e + f + g = 7 to 15, (f + g) / (e + f + g) > 0.15 to 0.8, h = 0, or e + f + g = 13 to 32, (f + g) / (e + f + g) > 0.25 to 0.8, particularly preferably 0.3 to 0.4, h = 0 and wherein polyether siloxanes according to formula 1 are used in a total amount of 0.1 to 15 parts by weight, preferably 0.5 to 10 parts by weight, particularly preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total polyol component.

2. Composition according to claim 1, characterized in that at least one polyether siloxane according to formula (1) is present, which contains at least two polyethers of the general formula (2), wherein at least one of these polyethers must satisfy category 1 and at least one of these polyethers must satisfy category 2 and the preferred ratio of polyethers of category 1 and polyethers of category 2 in the polyether siloxane in question corresponds to 10:90 to 90:10 wt.%, particularly preferably 20:80 to 80:20 wt.%, in particular 30:70 to 70:30 wt.%.

3. Composition according to claim 1 or 2, characterized in that at least two polyether siloxanes according to formula (1) are present, wherein at least one of these polyether siloxanes contains at least one polyether of the general formula (2) which satisfies category 1 and at least one of these polyether siloxanes contains at least one polyether of the general formula (2) which satisfies category 2 and wherein the preferred ratio of polyether siloxanes of the formula (1) containing at least one polyether of category 1 and polyether siloxanes of the formula (1) containing at least one polyether of category 2 is 10:90 to 90:10 wt.%, particularly preferably 20:80 to 80:20 wt.%, in particular 30:70 to 70:30 wt.%.

4. Composition according to one of claims 1 to 3, characterized in that the at least one solid is used in a total amount of 5 to 100 parts by weight, preferably 5 to 80 parts by weight, particularly preferably 10 to 50 parts by weight, based on 100 parts by weight of the total polyol component.

5. Composition according to one of claims 1 to 4, characterized in that the at least one solid is selected from the group consisting of (a) solid flame retardants, preferably ammonium polyphosphate, melamine, melamine-coated ammonium polyphosphate, melamine microencapsulated ammonium polyphosphate, melamine-formaldehyde resin microencapsulated ammonium polyphosphate, melamine cyanurate, red phosphorus, zinc borate, melamine polyphosphate, expandable graphite and / or antimony trioxide, (b) plastic powder, and (c) calcium carbonate, graphite, graphene, lignin and / or lignocellulose.

6. Composition according to claim 5, characterized in that the plastic powder consists of at least one plastic selected from the group consisting of polyethylene, polypropylene, polyamide, such as in particular PA6, PA6.6, PA10, PA11 and / or PA12, polyester, such as in particular polyethylene terephthalate, polybutylene terephthalate and / or poly-e- Caprolactone, polystyrene, polyacrylate, polymethyl methacrylate, polycarbonate, styrene-acrylonitrile copolymers, polyether, polylactic acid, polyurethane, polysulfone, polyethersulfone, polyetherimide and polyimide or mixtures thereof, wherein the plastic powder can particularly preferably be formed from waste plastics, especially preferably from PU waste plastics.

7. Composition according to one of claims 1 to 6, characterized in that one or more plastic powders made from waste plastics, preferably from recycled polyurethanes, are contained as solid.

8. Composition according to one of claims 1 to 7, characterized in that the solid is a powder with an average diameter of < 500 pm, preferably < 200 pm, particularly preferably < 80 pm.

9. Composition according to one of claims 1 to 8, characterized in that the composition contains as propellant (i) hydrocarbons having 3, 4 or 5 carbon atoms, preferably cyclo-, iso- and / or n-pentane, and / or (ii) hydrofluoroolefins and / or hydrohaloolefins, preferably 1234ze, 1234yf, 1224yd, 1233zd(E) and / or 1336mzz and necessarily water.

10. Process for producing PU foam, preferably rigid polyurethane foam, based on a reaction mixture containing a composition as defined in any one of claims 1 to 9.

11. PU foam, in particular PU rigid foam, produced according to the process of claim 10.

12. Use of PU foam, in particular PU rigid foam, according to claim 11 as insulating material and / or as construction material, in particular in building applications, in particular in spray foam and / or 1- & 1.5-component canned foam or in the refrigeration sector, as sound absorption material, as packaging foam, as wood imitation, as model foam, as headliner for automobiles, as automobile interior paneling, as sealing foam or pipe sheathing for tubes.

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