Manufacture of polyurethane foam

Abstract

To provide a composition for producing rigid polyurethane foam.SOLUTION: There is provided a composition which comprises at least one isocyanate component, a polyol component and optionally a catalyst that catalyzes the formation of a urethane bond or an isocyanurate bond, wherein the composition has a hydrocarbon having 3, 4 or 5 carbon atoms, hydrofluorocarbon, hydrofluoroolefin (HFO), hydrohaloolefin, an oxygen-containing foaming agent and / or chlorohydrocarbon as a foaming agent and comprises an acrylate and / or methacrylate copolymer as a form stabilizer.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention belongs to the field of polyurethane foams. In particular, the present invention relates to the production of rigid polyurethane foams using a predetermined blowing agent and an acrylate and / or methacrylate copolymer as a foam stabilizer. The present invention further relates to the corresponding compositions and the use of the foams produced according to the present invention. The polyurethane foam is particularly a rigid polyurethane foam.

[0002] In the present invention, polyurethane (PU) is understood to particularly mean a product obtained by the reaction of a polyisocyanate with a polyol or a compound having an isocyanate-reactive group. Here, in addition to polyurethane, other functional groups such as uretdione, carbodiimide, isocyanurate, allophanate, biuret, urea and / or uretonimine can also be formed. Therefore, in the spirit of the present invention, not only polyurethane but also polyisocyanurate; polyurea; and polyisocyanate reaction products containing uretdione groups, carbodiimide groups, allophanate groups, biuret groups and uretonimine groups are understood to be PU. In the present invention, polyurethane foam (PU foam) is understood to mean a foam obtained as a reaction product based on a polyisocyanate and a polyol or a compound having an isocyanate-reactive group. Here, in addition to what is called polyurethane, other functional groups such as allophanate, biuret, urea, carbodiimide, uretdione, isocyanurate or uretonimine can also be formed. The most preferred foam in the present invention is a rigid polyurethane foam.

[0003] For the production of polyurethane and polyisocyanurate foams, especially the corresponding rigid foams, bubble stabilizers or foam stabilizers are used. These additives are intended to provide a foam structure that is uniform with fine bubbles and has few defects, and as a result, have a great positive impact on the use properties, such as especially the heat insulation performance of rigid foam materials. Surfactants based on polyether-modified siloxanes are particularly effective, and thus this is a preferred type of foam stabilizer.

[0004] Regarding the use of siloxane-based additives, various publications have already been published. In this case, mainly polyether siloxane foam stabilizers (PES) are used.

[0005] European Patent No. 0570174 describes polyether siloxanes suitable for the production of rigid polyurethane foams using organic blowing agents, especially chlorofluorocarbons such as CFC-11.

[0006] European Patent Application Publication No. 0533202 describes polyether siloxanes having SiC-bonded polyalkylene oxide groups, which are suitable when using hydrofluorocarbons such as HCFC-123 as blowing agents.

[0007] European Patent No. 0877045 describes a similar structure for this production method, which is different from the previously mentioned foam stabilizers in terms of a relatively high molecular weight and the combination of two polyether substituents on the siloxane chain.

[0008] European Patent Application Publication No. 1544235 describes typical polyether-modified siloxanes for rigid PU foam applications. Here, siloxanes having 60 to 130 Si atoms, different polyether substituents R, a mixed molar mass of 450 to 1000 g / mol, and an ethylene oxide ratio of 70 to 100 mol% are used.

[0009] Chinese Patent Application Publication No. 103055759 describes a polyether-modified siloxane for improving the bubble release degree. This siloxane contains at least 18 Si units, and various types of side chains are used for modification.

[0010] European Patent Application Publication No. 1873209 describes a polyether-modified siloxane for producing a rigid PU foam with improved fire resistance. Here, the siloxane contains 10 - 45 Si atoms, and at least 90% of the polyether side chains consist of ethylene oxide units.

[0011] European Patent Application Publication No. 2465891 describes a polyether-modified siloxane having an OH group in a part of the polyether side chain. Here, the siloxane contains at least 10 Si atoms.

[0012] European Patent Application Publication No. 2465892 describes a polyether-modified siloxane whose polyether side chain mainly has a secondary OH terminal group, and here too the siloxane contains at least 10 Si atoms.

[0013] German Patent Invention No. 3234462 describes a siloxane for use in soft foams, especially soft molded foams. Here, a combination of a polyether-modified siloxane (PES) and polydimethylsiloxane is described, and PES contains 4 - 15 Si units.

[0014] Nevertheless, there is still a need for a further foam stabilizer for PU foams, preferably rigid PU foams, especially a foam stabilizer that enables foam stabilization basically without using siloxanes.

[0015] A specific problem of the present invention was to enable the provision of a rigid PU foam that can achieve foam stabilization basically without using siloxanes.

[0016] Surprisingly, it has been found that by using a predetermined blowing agent in combination with an acrylate and / or methacrylate copolymer as a foam stabilizer, rigid PU foams can be produced with complete quality. Blowing agents that can be used in the present invention include hydrocarbons having 3, 4 or 5 carbon atoms, hydrofluorocarbons, hydrofluoroolefins (HFOs), hydrohaloolefins, oxygen-containing blowing agents, and / or chlorohydrocarbons.

[0017] By the combination of a blowing agent and an acrylate and / or methacrylate copolymer as a foam stabilizer according to the present invention, foam stabilization can be achieved basically without using siloxane, that is, siloxane-based additives such as known polyether siloxane foam stabilizers can be completely eliminated. However, it is also possible to use them in combination with siloxane-containing stabilizers known from the prior art. Both are included in the present invention.

[0018] Against this background, the present invention relates to a composition for producing a rigid polyurethane foam, the composition comprising at least one isocyanate component, a polyol component, and optionally a catalyst that catalyzes the formation of urethane bonds or isocyanurate bonds, the composition having, as a blowing agent, a hydrocarbon having 3, 4 or 5 carbon atoms, a hydrofluorocarbon, a hydrofluoroolefin (HFO), a hydrohaloolefin, an oxygen-containing blowing agent, and / or a chlorohydrocarbon, and comprising, as a foam stabilizer, an acrylate and / or methacrylate copolymer.

[0019] According to the subject matter of the present invention, it is possible to provide rigid PU foams without using known siloxane-containing stabilizers. Nevertheless, the resulting PU foams meet the known requirements. These are, advantageously, dimensionally stable, show hydrolysis resistance, and exhibit excellent long-term properties. These are, advantageously, very good thermal insulation properties, very high heat capacity, high mechanical strength, high rigidity, and high compressive strength. However, furthermore, according to the subject matter of the present invention, it is also possible to provide rigid PU foams in combination with siloxane-containing stabilizers known from the prior art.

[0020] Acrylate and / or methacrylate copolymers are already known from the prior art.

[0021] It is a particularly preferred embodiment of the present invention that the acrylate and / or methacrylate copolymers usable according to the present invention are based on at least one comonomer of the type H2C=CR 1 -COOR 2 and at least one comonomer of the type H2C=CR 1 -COOR 3 where R 1 is -H or -CH3, and different comonomers having different substituents R 1 can be present in one molecule, R 2 is, independently of one another, a group from the group of saturated or unsaturated, linear, cyclic or branched, aliphatic or aromatic hydrocarbons having 1 to 25 carbon atoms, preferably methyl, ethyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, isodecyl, cyclohexyl, benzyl, phenyl, isobornyl or allyl, and different comonomers having different substituents R 2 can be present in one molecule, R 3 is, independently of one another, a group from the group of polyethers based on structural formula 1, where different substituents R3 Different comonomers having [it] can be present within one molecule, [Chemical formula] Here, x is from 3 to 500, preferably >5, particularly 8 to 100, R 4 is, independently of one another, a hydrogen group or a group from the group of saturated or unsaturated, linear, cyclic or branched, aliphatic or aromatic hydrocarbons having 1 to 12 carbon atoms, particularly preferably -H, methyl, ethyl or styryl, where, in the group R 3 different substituents R 4 can be present in any order or arrangement, R 5 is -CH2-O-, -CH2-CH2-O-, -CH2-CH2-CH2-O-, -CH2-CH2-CH2-CH2-O-, or -CH2-CH2-CH2-CH2-CH2-O-, where R 5 may not be present, R 6 is, independently of one another, a hydrogen group; a group from the group of saturated or unsaturated, linear, cyclic or branched, aliphatic or aromatic hydrocarbons having 1 to 25 carbon atoms; an acyl group; a group of the structural formula -CH2-CH(OH)-CH2OH; or a group of the structural formula -CH2-C(CH2OH)2-CH2-CH3, particularly preferably -H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or t-butyl, where different comonomers having different substituents R 6 can be present within one molecule.

[0022] It is a further particularly preferred embodiment of the present invention that the acrylate and / or methacrylate copolymer usable according to the present invention has a number average molecular weight Mn in the range of 500 to 100,000 g / mol, particularly preferably 1,000 to 20,000 g / mol, as determined by gel permeation chromatography (eluent: THF, standard substance: PMMA) in accordance with DIN 55672-1:2016-03.

[0023] The acrylate and / or methacrylate monomers usable in the context of the present invention are also commercially available, for example, under the trade name VISIOMER from Evonik Operations GmbH.

[0024] Examples of these include, but are not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenylethyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, hydroxyalkyl (meth)acrylate, such as 3-hydroxypropyl methacrylate, 3,4-dihydroxybutyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2,5-dimethyl-1,6-hexanediol (meth)acrylate, 1,10-decanediol (meth)acrylate; glycol dimethacrylate, such as 1,4-butanediol methacrylate, 2-butoxyethyl methacrylate, 2-ethoxyethoxymethyl methacrylate, 2-ethoxyethyl methacrylate; methacrylate of ether alcohol, such as tetrahydrofurfuryl methacrylate, vinyloxyethoxyethyl methacrylate, methoxyethoxyethyl methacrylate, 1-butoxypropyl methacrylate, 1-methyl(2-vinyloxy)ethyl methacrylate, cyclohexyloxymethyl methacrylate, methoxymethoxyethyl methacrylate, benzyloxymethyl methacrylate, furfuryl methacrylate, 2-butoxyethyl methacrylate, 2-ethoxyethoxymethyl methacrylate, 2-ethoxyethyl methacrylate, allyloxymethyl methacrylate, 1-ethoxybutyl methacrylate, methoxymethyl methacrylate, 1-ethoxyethyl methacrylate, ethoxymethyl methacrylate, and ethoxylated or propoxylated (meth)acrylate having preferably 1 to 20, particularly 2 to 8 ethoxy groups or propoxy groups.

[0025] The notation (meth)acrylate in this specification means both methacrylates such as methyl methacrylate and ethyl methacrylate, and acrylates such as methyl acrylate and ethyl acrylate, as well as mixtures of both.

[0026] Furthermore, methods for producing usable acrylate and / or methacrylate copolymers are known from the prior art and are described, for example, in European Patent Application Publication No. 1070730 or U.S. Patent No. 9349500.

[0027] As initiators, in principle, compounds that decompose into radicals under polymerization conditions can be used, such as, for example, peroxides, hydroperoxides, hydrogen peroxide, persulfates, azo compounds, and so-called redox initiators. In some cases, it may be advantageous to use a mixture of different initiators, such as, for example, a mixture of hydrogen peroxide and sodium or potassium peroxodisulfate. Organic peroxides include, for example, acetylacetone peroxide, methyl ethyl ketone peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tert-amyl perpivalate, tert-butyl perpivalate, tert-butyl perneohexanoate, tert-butyl perisobutyrate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl perisononanoate, tert-butyl permaleate, tert-butyl perbenzoate, di(2-ethylhexyl) peroxydicarbonate, dicyclohexyl peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, dimyristyl peroxydicarbonate, diacetyl peroxydicarbonate, allyl peresters, cumyl peroxyneodecanoate, tert-butyl per-3,5,5-trimethylhexanoate, acetylcyclohexylsulfonyl peroxide, dilauryl peroxide, and tert-amyl peroxy-2-ethylhexanoate. Other initiators are azo compounds, such as, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile).

[0028] Surprisingly, in the present invention, it has been found that better results regarding the results required by the present invention can be obtained. Therefore, in the present invention, it is preferable to produce the acrylate and / or methacrylate copolymer according to the present invention using tert-butyl peroxy-2-ethylhexanoate (TBPEH), or tert-amyl peroxy-2-ethylhexanoate (APO), or a combination of TBPEH and APO as an initiator. However, it has been found that acrylate and / or methacrylate copolymers produced especially using dibenzoyl peroxide (BPO) as an initiator are rather harmful and unsuitable for the benefits of the present invention. Therefore, the fact that the acrylate and / or methacrylate copolymer usable according to the present invention is produced without using BPO as an initiator corresponds to a particularly preferred embodiment of the present invention.

[0029] Furthermore, the fact that the residual monomer content of the acrylate and / or methacrylate copolymer is <1% corresponds to a particularly preferred embodiment of the present invention. The residual monomer content can be determined by conventional methods, particularly by solids content, or using GC or HPLC. The corresponding composition enables a particularly advantageous foam according to the present invention, which is even lower in emissions.

[0030] In addition to the acrylate and / or methacrylate copolymer that can be used as a foam stabilizer according to the present invention, a predetermined blowing agent is used in the spirit of the present invention, which includes hydrocarbons having 3, 4 or 5 carbon atoms, hydrofluorocarbons, hydrofluoroolefins (HFO), hydrochlorofluoroolefins, oxygen-containing blowing agents, and / or chlorohydrocarbons.

[0031] As blowing agents, hydrocarbons having 3, 4 or 5 carbon atoms, preferably cyclo-, iso- and / or n-pentane; hydrofluorocarbons, preferably HFC 245fa, HFC 134a and HFC 365mfc; perfluorinated compounds such as perfluoropentane, perfluorohexane and / or perfluorohexene; hydrofluoroolefins or hydrohaloolefins, preferably 1234ze, 1234yf, 1224yd, 1233zd(E) and / or 1336mzz; oxygen-containing compounds such as methyl formate, acetone and / or dimethoxymethane; and / or chlorohydrocarbons, preferably dichloromethane and / or 1,2-dichloroethane are used, which is a further particularly preferred embodiment of the present invention.

[0032] It is also a preferred embodiment of the present invention that the mass ratio of the total amount of acrylate and / or methacrylate copolymer to 100 parts by mass of the polyol component is 0.1 to 10 pphp, preferably 0.5 to 5 pphp, particularly preferably 1 to 4 pphp.

[0033] In the present invention, the Si-containing foam stabilizer can be eliminated. In this regard, a composition according to the present invention containing the Si-containing foam stabilizer in an amount less than 15% by mass, preferably less than 10% by mass, more preferably less than 5% by mass, still more preferably less than 3% by mass, even more preferably less than 1% by mass, particularly less than 0.5% by mass, or not containing it at all corresponds to a preferred embodiment of the present invention.

[0034] However, as described above, in the present invention, it is further possible to use a Si-containing foam stabilizer in combination. In this regard, a composition according to the present invention containing a Si-containing foam stabilizer in an amount of more than 1% by mass, preferably more than 10% by mass, particularly more than 20% by mass based on the total amount of the foam stabilizer corresponds to a preferred embodiment of the present invention. In such an embodiment, for example, a 50% by mass:50% by mass mixture is also possible, that is, the composition contains, in the same part, an acrylate and / or methacrylate copolymer usable according to the present invention and a Si-containing foam stabilizer. Surprisingly, it has been found that the acrylate and / or methacrylate copolymer usable according to the present invention improves the emulsifying ability of the Si-containing foam stabilizer.

[0035] In addition to the acrylate and / or methacrylate copolymer usable according to the present invention, in principle, all foam stabilizing components known from the prior art can be additionally used.

[0036] The acrylate and / or methacrylate copolymer usable according to the present invention may be used in bulk or in a solvent. Here, all suitable substances that can be used in the production of PU foams can be used. Preferably, substances already used in conventional formulations, such as OH-functional compounds, polyols, flame retardants, etc., can be used as the solvent.

[0037] Preferred compositions according to the present invention have the following components: a) the acrylate and / or methacrylate copolymer according to the present invention as described above, b) at least one polyol component, c) at least one polyisocyanate and / or polyisocyanate prepolymer, d) optionally, a catalyst that promotes or controls the reaction between the polyol b) and the isocyanate c), e) optionally, a further foam stabilizer, particularly a corresponding silicon-containing compound, f) the blowing agent according to the present invention as described above, g) Optionally, further additives, fillers, flame retardants, etc. and preferably, component d) is essentially included.

[0038] In addition to the acrylate and / or methacrylate copolymer according to the present invention and the blowing agent according to the present invention, components having at least two isocyanate-reactive groups, preferably polyol components, catalysts, and polyisocyanates and / or polyisocyanate prepolymers are used to produce polyurethane foams, which also corresponds to a preferred embodiment of the present invention. In that case, the catalyst is introduced particularly via the polyol component. Suitable polyol components, catalysts, polyisocyanates and / or polyisocyanate prepolymers are well known to those skilled in the art and will be described in more detail below.

[0039] Suitable polyols as the polyol component b) in the spirit of the present invention are all organic substances having two or more isocyanate-reactive groups, preferably OH groups, and their blends. Preferred polyols are all polyether polyols and / or polyester polyols and / or hydroxyl group-containing aliphatic polycarbonates, particularly polyether polycarbonate polyols, and / or polyols of natural origin known as "natural oil-based polyols" (NOP), which are customarily used in the production of polyurethane systems, particularly polyurethane coatings, polyurethane elastomers, or even foams. The polyol usually has a functionality of 1.8 to 8 and a number average molecular weight in the range of 500 to 15000. Polyols having a hydroxyl value in the range of 10 to 1200 mgKOH / g are usually used.

[0040] For the production of rigid PU foams, preferably a polyol or a mixture thereof is used, provided that at least 90 parts by mass of the polyol contained, based on 100 parts by mass of the polyol component, has a hydroxyl value greater than 100, preferably greater than 150, particularly greater than 200. The basic difference between flexible foams and rigid foams is that flexible foams exhibit elastic behavior and are reversibly deformable. When a force is applied to a flexible foam to deform it, it immediately returns to its original shape when the force is removed. In contrast, rigid foams are permanently deformed. This is well known to those skilled in the art.

[0041] Polyether polyols can be produced by known methods, for example, by anionic polymerization of alkylene oxides in the presence of an alkali metal hydroxide, an alkali metal alkoxide or an amine as a catalyst, preferably by adding at least one starter molecule containing two or three reactive hydrogen atoms in bonded form, or by cationic polymerization of alkylene oxides in the presence of a Lewis acid, such as antimony pentachloride or boron trifluoride etherate, or by double metal cyanide catalysis. Suitable alkylene oxides contain 2 to 4 carbon atoms in the alkylene group. Examples include tetrahydrofuran, 1,3-propylene oxide, 1,2-butylene oxide, or 2,3-butylene oxide, with ethylene oxide and 1,2-propylene oxide being preferably used. Alkylene oxides can be used individually, cumulatively, in block form, continuously and alternately, or as a mixture. Styrene oxide is also suitable. As starter molecules, in particular, compounds having at least two, preferably 2 to 8 hydroxyl groups in the molecule or having at least two primary amino groups can be mentioned. As starter molecules, for example, water, dihydric, trihydric or tetrahydric alcohols such as ethylene glycol, propane-1,2-diol and propane-1,3-diol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol, castor oil, etc., higher polyfunctional polyols, especially sugar compounds such as glucose, sorbitol, mannitol and sucrose, polyhydric phenols, resols, such as oligomeric condensation products of phenol and formaldehyde, and Mannich condensates of phenol, formaldehyde and dialkanolamine, and melamine, or amines such as aniline, EDA, TDA, MDA and PMDA, particularly preferably TDA and PMDA can be used. The selection of suitable starter molecules depends on the respective application fields of the polyether polyols obtained in the production of polyurethanes.

[0042] The polyester polyol is preferably based on esters of polyvalent aliphatic or aromatic carboxylic acids having 2 to 12 carbon atoms. Examples of aliphatic carboxylic acids are succinic acid, glutaric acid, adipic acid, pimelic 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 isomers of naphthalenedicarboxylic acid. The polyester polyol is obtained by condensation of these polyvalent carboxylic acids with polyhydric alcohols, preferably diols or triols having 2 to 12, particularly preferably 2 to 6 carbon atoms, preferably ethylene glycol, diethylene glycol, trimethylolpropane and glycerin.

[0043] A polyether polycarbonate polyol is a polyol that contains carbon dioxide in a bound form as a carbonate. Since carbon dioxide is produced in large quantities as a by-product in many processes of the chemical industry, the use of carbon dioxide as a comonomer in alkylene oxide polymerization is of particular interest from a commercial perspective. Partially replacing the alkylene oxide in the polyol with carbon dioxide has the potential to significantly reduce the manufacturing cost of the polyol. Furthermore, the use of CO2 as a comonomer is highly advantageous from an environmental perspective since this reaction is a conversion from a greenhouse gas to a polymer. The production of polyether polycarbonate polyols by adding alkylene oxide and carbon dioxide to an H-functional starter substance using a catalyst has been known for a long time. Here, various catalyst systems can be used, and the first generation was heterogeneous zinc or aluminum salts as described, for example, in US Patent No. 3,900,424 or US Patent No. 3,953,383. Furthermore, success has been achieved in using mononuclear and dinuclear metal complexes for the copolymerization of CO2 and alkylene oxide (WO 2010 / 028362, WO 2009 / 130470, WO 2013 / 022932, or WO 2011 / 163133). The most important class of catalyst systems for the copolymerization of carbon dioxide and alkylene oxide is the class of double metal cyanide catalysts, also called DMC catalysts (US Patent No. 4,500,704, WO 2008 / 058913). Suitable alkylene oxides and H-functional starter substances are those used for the production of carbonate-free polyether polyols as described above.

[0044] "Natural oil-based polyol" (NOP), a polyol based on renewable raw materials for the production of polyurethane foams, is gaining importance in view of the long-term limitations in the availability of fossil resources, namely petroleum, coal, and gas, and against the backdrop of rising crude oil prices, and has already been described several times for such applications (WO 2005 / 033167, US 2006 / 0293400 A1, WO 2006 / 094227, WO 2004 / 096882, US 2002 / 0103091 A1, WO 2006 / 116456, and EP 1678232 A1). A series of these polyols are currently commercially available from various manufacturers (WO 2004 / 020497, US 2006 / 0229375 A1, WO 2009 / 058367). Depending on the base raw material (e.g., soybean oil, palm oil, or castor oil) and subsequent post-treatment, polyols with different properties can be obtained. Here, they can be substantially distinguished into two groups, namely, a) polyols based on renewable raw materials that have been modified to be 100% usable in the production of polyurethanes (WO 2004 / 020497, US 2006 / 0229375 A1), and b) polyols based on renewable raw materials that, due to their post-treatment and properties, can only replace petrochemical-based polyols at a specific ratio (WO 2009 / 058367).

[0045] A further class of polyols that can be used are the so-called filled polyols (polymer polyols). These are characterized in that the polyol contains a solid organic filler in a dispersed form until the solid content reaches 40% or more. In particular, SAN, PHD, and PIPA polyols can be used. SAN polyol is a highly reactive polyol that contains a copolymer based on styrene - acrylonitrile (SAN) in a dispersed form. PHD polyol is a highly reactive polyol that contains a polyurea in a similar dispersed form. PIPA polyol is a highly reactive polyol that contains, for example, a polyurethane formed by reacting an isocyanate and an alkanolamine in situ in a conventional polyol in a dispersed form.

[0046] A further class of polyols that can be used are advantageously obtained as prepolymers by reacting a polyol and an isocyanate at a molar ratio of 100:1 to 5:1, preferably 50:1 to 10:1. Such prepolymers are advantageously prepared in a form dissolved in the polyol, where the polyol preferably corresponds to the polyol used in the production of the prepolymer.

[0047] The preferred ratio of isocyanate to polyol, expressed as a formulation index, i.e., 100 multiplied by the stoichiometric ratio of isocyanate groups to isocyanate - reactive groups (e.g., OH groups, NH groups), is in the range of 10 to 1000, preferably 40 to 500, in the context of the present invention. This corresponds to a preferred embodiment of the present invention. An index of 100 represents a molar ratio of reactive groups of 1:1.

[0048] As the isocyanate component c), one or more organic polyisocyanates having preferably two or more isocyanate functional groups are used. As the polyol component, one or more polyols having preferably two or more isocyanate - reactive groups, preferably OH groups, are used.

[0049] In the context of the present invention, suitable isocyanates as the isocyanate component are all isocyanates containing at least two isocyanate groups. Generally, all aliphatic, cycloaliphatic, araliphatic, and preferably aromatic polyfunctional isocyanates known per se can be used. Particularly preferably, the isocyanate is used in the range of 60 to 200 mol% based on the total of the components consuming the isocyanate.

[0050] Here, by way of example, alkylene diisocyanates having 4 to 12 carbon atoms in the alkylene group, such as dodecane-1,12-diisocyanate, 2-ethyltetramethylene-1,4-diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, tetramethylene-1,4-diisocyanate, and preferably hexamethylene-1,6-diisocyanate (HMDI); cycloaliphatic diisocyanates such as cyclohexane-1,3- and cyclohexane-1,4-diisocyanate, and any mixture of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, or briefly IPDI), hexahydrotoluylene-2,4-diisocyanate and hexahydrotoluylene-2,6-diisocyanate, and the corresponding isomer mixtures; preferably aromatic diisocyanates and polyisocyanates such as tolylene-2,4-diisocyanate and tolylene-2,6-diisocyanate (TDI), and the corresponding isomer mixtures, naphthalene diisocyanate, diethyltoluene diisocyanate, diphenylmethane-2,4'-diisocyanate and diphenylmethane-2,2'-diisocyanate (MDI) and a mixture of polyphenylpolymethylene polyisocyanates (crude MDI), and a mixture of crude MDI and tolylene diisocyanate (TDI) can be mentioned. The organic diisocyanates and polyisocyanates can be used individually or in the form of mixtures thereof. Similarly, the corresponding "oligomers" of diisocyanates (isocyanurate, biuret, IPDI trimer based on uretdione) can also be used. Furthermore, prepolymers based on the above-mentioned isocyanates can be used.

[0051] It is also possible to use isocyanates modified by incorporating urethane groups, uretdione groups, isocyanurate groups, allophanate groups, and other groups, so-called modified isocyanates.

[0052] Accordingly, particularly suitable organic polyisocyanates which are particularly preferably used are the various isomers of tolylene diisocyanate (toluene-2,4-diisocyanate and toluene-2,6-diisocyanate (TDI) in pure form or as a mixture of isomers of various compositions), diphenylmethane-4,4'-diisocyanate (MDI), so-called "crude MDI" or "polymeric MDI" (including the 4,4'-isomer of MDI, as well as the 2,4'- and 2,2'-isomers, and polynuclear products), and a binuclear product called "pure MDI" which consists mainly of a mixture of 2,4'- and 4,4'-isomers or a prepolymer thereof. Examples of particularly suitable isocyanates are described, for example, in European Patent Application Publication No. 1712578, European Patent Application Publication No. 1161474, International Publication No. 00 / 58383, US Patent Application Publication No. 2007 / 0072951, European Patent Application Publication No. 1678232, and International Publication No. 2005 / 085310, which are hereby incorporated by reference in their entirety.

[0053] Suitable catalysts d) which can optionally be used in the context of the present invention are all compounds which can accelerate the reaction of isocyanates with OH functional groups, NH functional groups or other isocyanate-reactive groups. Here, for example, amines (cyclic, acyclic monoamines, diamines, oligomers having one or more amino groups), organometallic compounds and metal salts can be used, and preferably those of iron, bismuth and zinc, and the usual catalysts known from the prior art can be used. In particular, mixtures of a plurality of components can be used as catalysts.

[0054] It has been found that the compositions according to the invention which do not contain tin-containing catalysts are particularly advantageous for achieving the results aimed at by the present invention. Accordingly, compositions according to the invention which are substantially free of tin-containing catalysts correspond to a particularly preferred embodiment of the present invention. The same applies to the method for producing rigid polyurethane foams described below. Also there, the substantially non-use of tin-containing catalysts corresponds to a preferred embodiment of the present invention.

[0055] Component e) is an optionally applicable additional foam stabilizer which is not an acrylate and / or methacrylate copolymer according to the invention. This may advantageously be a surfactant silicon-containing compound for further optimizing the desired cell structure and the foaming process. In the present invention, all Si-containing compounds which promote the formation of the foam (stabilization, cell control, cell opening degree, etc.) can be used. These compounds are well known from the prior art. As surfactant Si-containing compounds, all known compounds suitable for the production of PU foams can be used.

[0056] Corresponding siloxane structures which can be used in the context of the present invention are described, for example, in the following patent documents, although these patent documents only describe their use in classical polyurethane foams such as molded foams, mattresses, insulation materials, building foams, etc.: Chinese Patent Application Publication No. 103665385, Chinese Patent Application Publication No. 103657518, Chinese Patent Application Publication No. 103055759, Chinese Patent Application Publication No. 103044687, US Patent Application Publication No. 2008 / 0125503, US Patent Application Publication No. 2015 / 0057384, European Patent Application Publication No. 1520870, European Patent Application Publication No. 1211279, European Patent Application Publication No. 0867464, European Patent Application Publication No. 0867465, European Patent Application Publication No. 0275563. These documents are incorporated by reference and form part of the disclosure of the present invention.

[0057] As already mentioned above, the use of blowing agent f) is essential. At least one blowing agent according to the invention must be used. Additionally, further blowing agents can be used in combination if necessary. It is possible to work with chemical blowing agents and physical blowing agents.

[0058] Depending on the total amount of blowing agent used, high-density or low-density foams are produced. For example, 5 kg / m 3 ~900 kg / m 3A foam having the density can be produced. Preferred densities are 8 to 800 kg / m 3 , particularly preferably 10 to 600 kg / m 3 , especially 30 to 150 kg / m 3 .

[0059] As the physical blowing agent, basically, the corresponding compound having an appropriate boiling point can be used. Similarly, basically, a chemical blowing agent that reacts with the NCO group to release gas, such as water or formic acid, can also be used. Examples of conventional blowing agents are liquefied CO2, nitrogen, air, and volatile liquids.

[0060] As optional additive g), all substances known from the prior art and used in the production of polyurethanes, preferably PU foams, particularly rigid polyurethane foams, can be used. For example, crosslinking agents and chain extenders, stabilizers against oxidative degradation (so-called antioxidants), flame retardants, surfactants, biocides, bubble refinement additives, bubble openers, solid fillers, antistatic additives, nucleating agents, thickeners, dyes, pigments, color pastes, fragrances, emulsifiers, etc. can be used.

[0061] As a flame retardant, the composition according to the invention can have all known flame retardants suitable for the production of polyurethane foams. Suitable flame retardants within the scope of the present invention are preferably liquid organic phosphorus compounds, such as halogen-free organic phosphates, such as triethyl phosphate (TEP); halogenated phosphates, such as tris(1-chloro-2-propyl) phosphate (TCPP), and tris(2-chloroethyl) phosphate (TCEP); and organic phosphonates, such as dimethylmethane phosphonate (DMMP), dimethylpropane phosphonate (DMPP); or solids, such as ammonium polyphosphate (APP), and red phosphorus. Furthermore, as flame retardants, halogenated compounds, such as halogenated polyols; and solids, such as exfoliated graphite, aluminum oxide, antimony compounds, and melamine are suitable. By using acrylate and / or methacrylate copolymers according to the invention, very large amounts of flame retardants can be used, and in particular, liquid flame retardants such as TEP, TCPP, TCEP, DMMP, etc. can also be used. However, this usually results in a formulation that is rather unstable.

[0062] The present invention further provides a method for producing a rigid polyurethane foam by reacting one or more polyol components with one or more isocyanate components, wherein the reaction is carried out in the presence of a hydrocarbon having 3, 4 or 5 carbon atoms, a hydrofluorocarbon, a hydrofluoroolefin (HFO), a hydrohaloolefin, an oxygen-containing blowing agent, and / or a blowing agent containing a chlorohydrocarbon, and an acrylate and / or methacrylate copolymer as a foam stabilizer, in particular using the composition according to the invention as described above. To avoid repetition, reference is hereby made to the above text. In particular, reference is made to the above text with respect to the preferred embodiments of the present invention. The acrylate and / or methacrylate copolymer according to the invention acts as a foam stabilizer.

[0063] The rigid PU foam that can be used according to the present invention preferably has a density of 5 kg / m 3 ~900 kg / m 3 Preferably 8~800 kg / m 3 Particularly preferably 10~600 kg / m 3 Especially 20~150 kg / m 3 and has a density of.

[0064] In particular, a closed-cell rigid PU foam can be obtained, and the closed-cell ratio is preferably >80%, more preferably >90%. This corresponds to a very particularly preferred embodiment of the present invention. In the context of the present invention, the determination of the closed-cell ratio is preferably carried out using a pycnometer in accordance with DIN EN ISO 4590:2016-12.

[0065] The method for producing the rigid PU foam according to the present invention can be carried out by known methods, for example, by hand mixing or preferably using a foaming machine. When the method is carried out using a foaming machine, high-pressure or low-pressure equipment can be used. The method according to the present invention can be carried out batchwise or continuously.

[0066] A preferred rigid polyurethane or polyisocyanurate foam formulation in the context of the present invention provides a density of 5~900 kg / m 3 and has the composition shown in Table 1.

[0067]

Table 1

[0068] For further preferred embodiments and configurations of the method according to the present invention, reference is further made to the detailed discussion already given above in connection with the composition according to the present invention, in particular the preferred embodiments mentioned therein.

[0069] The present invention further provides a rigid PU foam obtained by the above-described method.

[0070] According to a further preferred embodiment of the present invention, the rigid PU foam has a density of 5 to 900 kg / m 3 , preferably 8 to 750 kg / m 3 , particularly preferably 10 to 350 kg / m 3 , especially 20 to 150 kg / m 3 and the closed cell ratio is advantageously >80%, preferably >90%.

[0071] The rigid polyurethane foam according to the present invention is advantageously, as described above, characterized in that the rigid polyurethane foam contains at least one acrylate and / or methacrylate copolymer according to the present invention and is obtained using a blowing agent according to the present invention, preferably by a method according to the present invention.

[0072] The PU foam (polyurethane or polyisocyanurate foam) according to the present invention is a rigid PU foam and can be used as a heat insulating material, advantageously as a partition board, refrigerator, insulating foam, vehicle seat, especially an automobile seat, roof liner, mattress, filter foam, packaging foam, or spray foam, or for their manufacture.

[0073] Particularly in the refrigerated warehouse, refrigeration appliance, and household appliance industries, for example, in the manufacture of partition boards for roofs and walls, as a heat insulating material in containers for refrigerated products and storage warehouses, and in refrigerators and freezers, the PU foam according to the present invention, especially the rigid PU foam, can advantageously be used.

[0074] Further preferred application fields are the assembly of automobiles, especially the manufacture of automobile roof liners, body parts, interior trims, refrigerated trucks, large containers, transport pallets, packaging laminates, the furniture industry, for example furniture parts, doors, linings, and electronic equipment applications.

[0075] The cooling device according to the present invention has, as a heat insulating material, a rigid PU foam (polyurethane or polyisocyanurate foam) according to the present invention.

[0076] The present invention further provides for the use of the rigid PU foam as a heat insulating material, as a partition plate, as a spray foam, as a one-component foam in the cooling industry, cooling units, construction, automotive, shipbuilding and / or electronics fields.

[0077] The present invention further relates to the use of a composition according to the invention comprising an acrylate and / or methacrylate copolymer as a foam stabilizer as described above and a blowing agent according to the invention as described above for providing a rigid polyurethane foam having improved heat insulating properties.

[0078] The subject matter according to the invention is illustrated by way of example above or below, but the invention is not limited to these exemplary embodiments. If ranges, general formulas, or compound classes are shown above or below, these shall include not only the corresponding ranges or compound groups explicitly mentioned, but also all partial ranges and subgroups of compounds obtained by extracting individual values (ranges) or compounds. Further, if a document is cited herein, its content, in particular the content regarding the situation in the context in which the document is cited, shall form an integral part of the disclosure of the present invention. Unless otherwise specified, the numerical values of percentages are mass percentages. If an average value is shown above or below, it is a weight average unless otherwise specified. If a parameter determined by measurement is shown above or below, the measurement was carried out at a temperature of 25 °C and a pressure of 101,325 Pa unless otherwise specified.

[0079] The examples shown below illustrate the present invention by way of example. The scope of application of the present invention is clear from the entire specification and the claims, and the present invention is not limited to the embodiments listed in the examples.

[0080] Examples: Example 1: Synthesis of Copolymers A - F Copolymer A: A 500 mL four-necked flask equipped with a reflux condenser, an N2 conduit, a servo stirrer (200 rpm), and a Pt100 digital internal thermometer was charged with 30.01 g of n-butyl acetate, and the oil bath was heated to 145 °C. A mixture of 9.2 g of TBPEH (tert-butyl peroxy-2-ethylhexanoate), 56.18 g of isobutyl methacrylate (i-BMA), 67.29 g of MPEG500 methacrylate (MPEG500MA), and 2.21 g of 2-mercaptoethanol was fed using a tube pump over 4 hours. The mixture was stirred at this temperature for an additional 30 minutes. The mixture was cooled to 80 °C, and a solution of 0.13 g of TBPEH dissolved in 10 g of n-butyl acetate was fed for the post-reaction, and the mixture was stirred at 80 °C for 2 hours. An additional 5 g of n-butyl acetate was added, and the mixture was stirred for an additional 30 minutes without heating.

[0081] GPC (eluent: THF, standard substance: PMMA) conforming to DIN 55672-1:2016-03: Mw = 5630 g / mol, Mn = 2560 g / mol, PDI = 2.2

[0082] Copolymer B: A 500 mL four-necked flask equipped with a reflux condenser, an N2 conduit, a servo stirrer (200 rpm), and a Pt100 digital internal thermometer was charged with 30.01 g of n-butyl acetate, and the oil bath was heated to 145 °C. A mixture of 9.2 g of TBPEH, 54.69 g of isodecyl methacrylate (IDMA), 68.77 g of MPEG500MA, and 2.21 g of 2-mercaptoethanol was fed using a tube pump over 4 hours. The mixture was stirred at this temperature for an additional 30 minutes. The mixture was cooled to 80 °C, and a solution of 0.13 g of TBPEH dissolved in 10 g of n-butyl acetate was fed for the post-reaction, and the mixture was stirred at 80 °C for 2 hours. An additional 5 g of n-butyl acetate was added, and the mixture was stirred for an additional 30 minutes without heating.

[0083] GPC (eluent: THF, standard substance: PMMA) compliant with DIN 55672-1:2016-03: Mw = 5250 g / mol, Mn = 2410 g / mol, PDI = 2.2

[0084] Copolymer C: 30.01 g of n-butyl acetate was charged into a 500 mL four-necked flask equipped with a reflux condenser, an N2 conduit, a servo stirrer (200 rpm), and a Pt100 digital internal thermometer, and the oil bath was heated to 145 °C. A mixture of 20.75 g of BP-50-FT (BPO), 50.92 g of i-BMA, 60.99 g of MPEG500MA, and 2.21 g of 2-mercaptoethanol was fed using a tube pump over 4 hours. The mixture was stirred at this temperature for an additional 30 minutes. The mixture was cooled to 80 °C, and a solution of 0.13 g of BP-50-FT dissolved in 10 g of n-butyl acetate was fed for the post-reaction, and the mixture was further stirred at 80 °C for 2 hours. An additional 5 g of n-butyl acetate was added, and the mixture was further stirred for 30 minutes without heating.

[0085] GPC (eluent: THF, standard substance: PMMA) compliant with DIN 55672-1:2016-03: Mw = 6350 g / mol, Mn = 4080 g / mol, PDI = 1.6

[0086] Copolymer D: A 1000 mL four-necked flask equipped with a reflux condenser, an N2 conduit, a magnetic stirrer (100 rpm), and a Pt100 digital internal thermometer was charged with a mixture of 265.05 g of petroleum benzine (bp 100 - 120 °C) and 265.05 g of toluene, and the oil bath was heated to 135 °C. A mixture of 4.43 g of BP-50-FT, 90.59 g of C17.4MA (stearyl methacrylate), 55.02 g of MPEG350MA (MPEG350 methacrylate), and 19.06 g of i-BMA was fed using a tube pump over 5 hours. After the feeding was completed, 0.40 g of BP-50-FT was added for the post-reaction, and the mixture was stirred for an additional 2 hours. This was cooled to room temperature, and this batch was left in the flask overnight without stirring. The oil bath was heated to 130 °C again, 0.40 g of BP-50-FT was added again, and the mixture was stirred for 3 hours.

[0087] This mixture was concentrated using a rotary evaporator to completely remove the solvent mixture. 150 g of the solvent-free polymer was dissolved in 150 g of n-butyl acetate.

[0088] GPC (eluent: THF, standard substance: PMMA) conforming to DIN 55672-1:2016-03: Mw = 14900 g / mol, Mn = 8610 g / mol, PDI = 1.7

[0089] Copolymer E: Into a 500 mL four-necked flask equipped with a reflux condenser, an N2 conduit, a dropping funnel, a KPG stirrer (200 rpm), and a Pt100 digital internal thermometer, 29.9 g of n-butyl acetate was charged, and the oil bath was heated to 145 °C. A mixture of 9.8 g of APO, 56.0 g of i-BMA, 67.1 g of MPEG500MA, and 2.2 g of 2-mercaptoethanol was added dropwise over 4 hours. At that time, first, it was added dropwise over 1.5 hours at a dropping rate of 1 drop every 4 seconds, and then it was added dropwise over another 2.5 hours at a dropping rate of 1 drop every 2 seconds, and this mixture was stirred at this temperature for an additional 30 minutes. The mixture was cooled to 80 °C, and a solution of 0.14 g of APO dissolved in 10 g of n-butyl acetate was supplied for the post-reaction. Further, 15 g of isobutyl acetate was added, and the mixture was stirred for an additional 30 minutes without heating.

[0090] GPC (eluent: THF, standard substance: PMMA) conforming to DIN 55672-1:2016-03: Mw = 8474 g / mol, Mn = 2426 g / mol, PDI = 3.5

[0091] Copolymer F: Into a 550 mL four-necked flask equipped with a reflux condenser, an N2 conduit, a dropping funnel, a KPG stirrer (200 rpm), and a Pt100 digital internal thermometer, 29.9 g of n-butyl acetate was charged, and the oil bath was heated to 145 °C. A mixture of 9.8 g of APO, 56.0 g of i-BMA, 67.1 g of MPEG500MA, and 2.2 g of 2-mercaptoethanol was continuously added dropwise over 4 hours at a dropping rate of 1 drop every 2 seconds, and this mixture was stirred at this temperature for an additional 30 minutes. The mixture was cooled to 80 °C, and a solution of 0.14 g of APO dissolved in 10 g of n-butyl acetate was supplied for the post-reaction. Further, 15 g of isobutyl acetate was added, and it was stirred for an additional 30 minutes without heating.

[0092] GPC (eluent: THF, standard substance: PMMA) conforming to DIN 55672-1:2016-03: Mw = 6181 g / mol, Mn = 2276 g / mol, PDI = 2.7

[0093] Example 2: Rigid PUR Foam For comparative application technology, the following foam formulations were used: [Table 2]

[0094] The comparative foaming was carried out by the hand mixing method. For this purpose, polyol, catalyst, water, foam stabilizer, and blowing agent were weighed into a beaker and mixed at 1000 rpm for 30 seconds using a disk-type stirrer (diameter 6 cm). The amount of blowing agent evaporated during the mixing process was weighed again to obtain and replenished. Here, MDI was added, and the reaction mixture was stirred at 2500 rpm for 7 seconds with the described stirrer and immediately transferred to an open mold with a size of 27.5×14×14 cm (width×height×depth).

[0095] After 10 minutes, the foam was demolded. One day after foaming, the foam was analyzed. The pore structure was subjectively evaluated on a scale of 1 to 10. At this time, 10 represents a very fine foam without (ideal) defects, and 1 represents a coarse foam with very strong strength defects.

[0096] The results were summarized in the following table: [Table 3]

[0097] From these results, it can be seen that by using especially copolymers A, B, as well as E and F, pore structures and foam qualities comparable to or slightly exceeding those of silicone-based bubble stabilizers can be achieved.

[0098] None of the other foam properties related to use are affected by, or are only very slightly affected by, the copolymers according to the present invention.

[0099] Example 3: Rigid PIR Foam For comparative application technology, the following foam formulations were used: [Table 4]

[0100] The comparison foams were made by the hand mixing method. For this purpose, polyol, catalyst, water, foam stabilizer, and blowing agent were weighed into a beaker and mixed for 30 seconds at 1000 rpm using a disk-shaped stirrer (6 cm in diameter). The amount of blowing agent evaporated during mixing was weighed again to determine and replenished. Here, MDI was added, and the reaction mixture was stirred for 5 seconds at 3000 rpm using the described stirrer and immediately transferred to an open mold sized 27.5×14×14 cm (width × height × depth).

[0101] After 10 minutes, the foam was demolded. One day after foaming, the foam was analyzed. The pore structure was subjectively evaluated on a scale of 1 to 10, where 10 represents a very fine foam without (ideal) defects, and 1 represents a coarse foam with very strong strength defects.

[0102] The results were summarized in the following table:

Table 5

[0103] From these results, it can be seen that especially by using copolymers A, B, and E and F, pore structures and foam qualities comparable to or slightly better than those of siloxane-based foam stabilizers can be achieved.

[0104] None of the other foam properties related to use are affected by, or are only very slightly affected by, the copolymers according to the invention.

[0105] Example 4: Rigid PIR foam For comparative application technology, the following foam formulations were used:

Table 6

[0106] The comparison foaming was carried out by the hand mixing method. For this purpose, polyol, catalyst, water, foam stabilizer, flame retardant, and blowing agent were weighed into a beaker and mixed at 1000 rpm for 30 seconds using a disk-type stirrer (6 cm in diameter). The amount of the blowing agent evaporated during the mixing process was weighed again to obtain and replenished. Here, MDI was added, and the reaction mixture was stirred at 3000 rpm for 5 seconds using the described stirrer, and immediately transferred to an aluminum mold sized 25 cm × 50 cm × 7 cm with a temperature adjusted to 60 °C and lined with a polyethylene film.

[0107] After 10 minutes, the foam was demolded. One day after the foaming, the foam was analyzed. The surface and internal defects were subjectively evaluated on a scale of 1 to 10, where 10 represents a (perfect) defect-free foam and 1 represents a foam with very strong strength defects. Using a 2.5 cm thick sheet, the thermal conductivity (λ value (mW / m·K)) was measured at an average temperature of 10 °C in accordance with the provisions of Standard EN12667:2001 using a Hesto Lambda Control, HLC X206 type device.

[0108] The results were summarized in the following table:

Table 7

[0109] From these results, it can be seen that by using especially copolymers A and B, foam quality and thermal conductivity comparable to or slightly exceeding those of a siloxane-based foam stabilizer can be achieved.

[0110] None of the other foam properties related to use are affected by the copolymers according to the present invention, or are affected only very slightly.

[0111] Example 5: Rigid PIR foam For the purpose of application technology comparison, the following foam formulations were used:

Table 8

[0112] The comparison foaming was carried out by the hand mixing method. For this purpose, polyol, catalyst, water, foam stabilizer, flame retardant, and blowing agent were weighed into a beaker and mixed at 1000 rpm for 30 seconds using a disk-type stirrer (diameter 6 cm). The amount of blowing agent evaporated during the mixing process was weighed again to obtain and replenished. Here, MDI was added, and the reaction mixture was stirred at 3000 rpm for 5 seconds with the described stirrer and immediately transferred to an aluminum mold sized 25 cm × 50 cm × 7 cm, lined with a polyethylene film and temperature-controlled at 60°C.

[0113] After 10 minutes, the foam material was demolded. One day after foaming, the foam material was analyzed. The surface and internal defects were subjectively evaluated on a scale of 1 - 10. At this time, 10 represents a (perfect) foam without defects, and 1 represents a foam with very strong strength defects. Using a 2.5 cm thick sheet, the thermal conductivity (λ value (mW / m·K)) was measured at an average temperature of 10°C in accordance with the provisions of standard EN12667:2001 using a Hesto Lambda Control, HLC X206 type device.

[0114] The results were summarized in the following table:

Table 9

[0115] From these results, it can be seen that by using copolymers A and B in particular, foam quality and thermal conductivity comparable to those of a siloxane-based bubble stabilizer can be achieved.

[0116] None of the other foam properties related to use are affected by the copolymers according to the present invention or are affected only very slightly.

Claims

1. A composition for producing rigid polyurethane foam, said composition comprising: at least one isocyanate component; a polyol component; optionally, a catalyst that catalyzes the formation of urethane or isocyanurate bonds; and said composition has, as a blowing agent, a hydrocarbon having 3, 4 or 5 carbon atoms, a hydrofluorocarbon, a hydrofluoroolefin (HFO), a hydrohaloolefin, an oxygen-containing blowing agent, and / or a chlorohydrocarbon, and, as a foam stabilizer, an acrylate and / or methacrylate copolymer, wherein said acrylate and / or methacrylate copolymer is produced using TBPEH (tert-butylperoxy-2-ethylhexanoate) and / or APO (tert-amylperoxy-2-ethylhexanoate) as an initiator, or said acrylate and / or methacrylate copolymer is produced without using dibenzoyl peroxide (BPO) as an initiator, or the residual monomer content of said acrylate and / or methacrylate copolymer is <1%, a composition characterized thereby.

2. the acrylate and / or methacrylate copolymer is based on at least one comonomer of the type H ２ C═CR １ —COOR ２ and at least one comonomer of the type H ２ C═CR １ —COOR ３ wherein R １ is, independently of one another, -H or -CH ３ and, in this case, different comonomers having different substituents R １ can be present within one molecule R ２ is, independently of one another, a group from the group of saturated or unsaturated, linear, cyclic or branched, aliphatic or aromatic hydrocarbons having 1 to 25 carbon atoms, where different substituents R ２ having different comonomers can be present within one molecule, R ３ is, independently of one another, a radical from the group of polyethers based on structural formula 1, where different comonomers having different substituents R ３ can be present within one molecule, 【Chemical 1】 wherein x is from 3 to 500; R ４ is, independently of one another, a hydrogen radical or a radical from the group of saturated or unsaturated, linear, cyclic or branched, aliphatic or aromatic hydrocarbons having from 1 to 12 carbon atoms, where the radicals R ３ in which different substituents R ４ can be present in any order or arrangement, R ５ is -CH ２ -O-, -CH ２ -CH ２ -O-, -CH ２ -CH ２ -CH ２ -O-, -CH ２ -CH ２ -CH ２ -CH ２ -O-, or -CH ２ -CH ２ -CH ２ -CH ２ -CH ２ -O-, and in this case, R ５ may not exist. R ６ is, independently of one another, a hydrogen group; a group from the group of saturated or unsaturated, linear, cyclic or branched, aliphatic or aromatic hydrocarbons having 1 to 25 carbon atoms; an acyl group; a structural formula -CH ２ -CH(OH)-CH ２ OH group; or a structural formula -CH ２ -C(CH ２ OH) ２ -CH ２ -CH ３ group, where different comonomers having different substituents R ６ can be present in one molecule, the composition according to claim 1.

3. The composition according to claim 1 or 2, wherein a hydrocarbon having 3, 4 or 5 carbon atoms; a hydrofluorocarbon; a perfluorinated compound; a hydrofluoroolefin or hydrohaloolefin; water; an oxygen-containing compound; and / or a chlorohydrocarbon is used as the blowing agent.

4. The composition according to claim 1 or 2, wherein the acrylate and / or methacrylate copolymer has a number average molecular weight Mn in the range of 500 to 100,000 g / mol as determined by gel permeation chromatography (eluent: THF, standard substance: PMMA) in accordance with DIN 55672-1:2016-03.

5. The composition according to claim 1 or 2, wherein the mass ratio of the total amount of the acrylate and / or methacrylate copolymer to 100 parts by mass of the polyol component is 0.1 to 10 pp hp.

6. The composition according to claim 1 or 2, wherein the Si-containing foam stabilizer is contained in an amount of less than 15% by mass based on the total amount of the foam stabilizer, or is not contained at all.

7. The composition according to claim 1 or 2, wherein the Si-containing foam stabilizer is contained in an amount of more than 10% by mass based on the total amount of the foam stabilizer.

8. The composition according to claim 1 or 2, wherein the composition substantially does not contain a tin-containing catalyst.

9. The composition according to claim 1 or 2, wherein the acrylate and / or methacrylate copolymer is produced using TBPEH (tert-butylperoxy-2-ethylhexanoate) and / or APO (tert-amylperoxy-2-ethylhexanoate) as an initiator.

10. The composition according to claim 1 or 2, wherein the acrylate and / or methacrylate copolymer is produced without using dibenzoyl peroxide (BPO) as an initiator.

11. The composition according to claim 1 or 2, wherein the residual monomer content of the acrylate and / or methacrylate copolymer is <1%.

12. A method for producing a rigid polyurethane foam by reacting one or more polyol components with one or more isocyanate components, wherein the reaction is carried out using the composition according to claim 1 or 2.

13. A rigid polyurethane foam obtained by the method according to claim 12.

14. Use of the composition according to claim 1 or 2 for providing a rigid polyurethane foam having improved heat insulation properties.

15. Use of the rigid polyurethane foam according to claim 13 as a barrier board and / or a heat insulating material.

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