Silicon stabilisers for polyurethane or polyisocyanurate rigid foams

The invention relates to polyether siloxanes and their use as foam stabilizers in the production of polyurethane foams or polyisocyanurate foams, in particular rigid foams, which exhibit particularly advantageous performance properties, such as low thermal conductivity and in particular good surface quality.

[0002] In the production of rigid polyurethane and polyisocyanurate foams, cell stabilizing additives are introduced that should provide a small cellular, even and undisturbed foam structure and thus have a significant positive effect on performance, in particular on insulating properties. Surfactants based on siloxane modified with polyethers, which are therefore a preferred type of foam stabilizers, are particularly effective.

[0003] Because there are many different rigid foam compositions, polyether siloxanes with different structures are used for different applications that require separate foam stabilizers. One of the criteria for choosing a foam stabilizer is the blowing agent (German: Treibmittel) contained in the rigid foam composition.

[0004] Many reports have recently been published regarding polysiloxane foam stabilizers for rigid foam applications. EP 0 570 174 B1 describes a polyether siloxane with the structure (CH3) 3SiO [SiO (CH3) 2] x [SiO (CH3) R] ySi (CH3) 3, whose R residues consist of polyethylene oxide connected to siloxane via SiC bond, which at the other end of the chain is terminated with a C1-C6 acyl group. This foam stabilizer is suitable for the production of rigid polyurethane foams using organic blowing agents, in particular fluorohydrocarbons such as CFC-11.

[0005] The next generation of fluorochlorohydrocarbons are so-called hydrochlorofluorocarbons, such as, for example, HCFC-123. When using these blowing agents for the production of rigid polyurethane foams, polyether siloxanes of EP 0 533 202 A1 having the structure type (CH3) 3SiO [SiO (CH3) 2] x [SiO (CH3) R] ySi (CH3) 3 are suitable. R residues consist of SiC-linked polyacylene oxides, which consist of propylene oxide and ethylene oxide, and may contain a hydroxyl, methoxy or acyloxy functional group at the end of the chain. The minimum ethylene oxide content of the polyether is 25 percent by mass.

[0006] EP 0 877 045 B1 describes analogous structures to those of this production method which differ from previous foam stabilizers by a relatively higher molecular weight and a combination of two polyether substituents on the siloxane chain.

[0007] In the production of rigid polyurethane foams with a pure fluorocarbon such as e.g. freon, mixtures of different stabilizers can also be used as blowing agent in accordance with EP 0 293 125 B1, for example a combination of a purely organic (silicon-free) surfactant with polyether siloxane.

[0008] Progress in the production of rigid polyurethane foams consists in completely abandoning halogenated hydrocarbons as blowing agents and introducing substitutes for hydrocarbons such as pentane. As also described in EP 1 544 235, the preparation of rigid polyurethane foams and the use of hydrocarbon blowing agents and polyether siloxanes with the known structure (CH3) 3SiO [SiO (CH3) 2] x [SiO (CH3) R] ySi (CH3) 3 with a minimum siloxane chain length of 60 monomers and various R polyether substituents, resulting in a mixed molecular weight of 450 to 1000 g / mol with 70 to 100 mol% related to the proportion of ethylene oxide.

[0009] DE 10 2006 030 531 describes the use of a foam stabilizer polyether siloxane in which the polyether end group is a free OH group, an alkylether (in particular methyl) group or an ester. Polyether siloxanes which contain free OH functions are particularly preferably used. The use of special polyether siloxanes should in particular have a positive effect on flammability.

[0010] US 4,014,825 describes organically modified siloxanes for the production of polyurethane foams which, in addition to alkyl and polyether substituents, have side chains with tertiary OH groups. Additional substituents have also been introduced. The polyethers used here are mostly terminated with methyl. In general, the polyethers do not show any special ordering of alkylene units so that in the absence of termination no fixed OH group occurs.

[0011] US 4,746,683 describes the improvement of the cellular openness of highly flexible soft foams by using polyethersiloxanes, with a high proportion of secondary or tertiary OH groups in the polyether. Siloxanes contain a maximum of 10 Si atoms and the polyether consists of 3 to 13 oxyalkylene units.

[0012] US 5,169,872 discloses a method for producing rigid polyurethane and polyisocyanurate foams wherein (I) a composition should be mixed which (i) contains at least one reactive diisocyanate, (ii) at least one active polyol, (iii) at least one catalyst , (iv) organic blowing agent, (v) water (vi) one specific addition of polyurethane foam, whereby this addition meets the general formula (CH3) 3SiO {SiO (CH3) 2} x {SiO (CH3) R} ySi (CH3) 3 wherein R is the residue (CnH2n) aO (CH2CH2O) in {CH2 (CH3) -CHO} zR ', wherein R' was selected from (C = O) R ", hydrogen and alkyl residues with 1 to 6 carbon atoms and R "wherein R" is selected from alkyl residues with 1 to 6 carbon atoms and where n is a value from 3 to 6; where x is a value from 27 to 33 and y is a value from 3 to 5, z is a value from 0 up to 1 and w is a value from 6 to 100 and whose ratio x to y is in the range 5: 1 to 12: 1; wherein the amount of organic blowing agents (iv) does not exceed the amount of water (v) in the initial mixture and (II) the initial mixture is allowed to react and cure, whereby hard polyurethane and polyisocyanurate foams with improved system flow and improved K value are obtained.

[0013] The foam stabilizers described in this text, however, do not offer the full range of different rigid foam compositions with optimal properties, and patches for foam stabilizers relative to the prior art are desirable for many areas of application to further optimize rigid foam application properties, in particular regarding thermal conductivity and surface defects of the foam.

[0014] The main attention is increasingly directed to foam surface defects. For example, for refrigerators and metal composite elements (building wall elements) in the processing of polyurethane foam with a steel sheet surface coating, shrinkage cavities located directly under the surface coating may mark on the foam in the form of bubbles or bumps on the surface of the coating and lead to an observer's low impression quality. In addition to the optical sensations, these foam defects also reduce the physical properties: surface layer adhesion and thermal insulation generally deteriorate from initial values ​​and may also undergo more severe changes and further deterioration. This problem is also known for polyurethane, e.g. polyisocyanurate insulation boards.

[0015] The number of shallow foam defects can be very efficiently influenced by the choice of foam stabilizer. Polyether siloxanes with so-called terminated polyether side groups, i.e. polyethers which instead of an OH group contain an alkylether or ester end group, are known for comparatively undisturbed surface quality. Unfortunately, these foam stabilizers are less soluble in the polyol composition than products with an OH function. The use of insoluble foam stabilizer in pre-formulated polyol systems, which are ubiquitously used on the market in the insulation of refrigerators and metal-connected components, is ruled out because of the threat of separation of formulation phases during prolonged storage prior to processing. For this reason, the use of foam finishers with completely closed ends to improve the surface quality in particular for refrigeration applications, but also for many other applications is not possible or is only possible to the limited extent.

[0016] This therefore contributes to the development of alternative foam stabilizers that allow obtaining high quality surface polyurethane or polyisocyanurate foams - in particular small amounts of shrinkage cavities and compaction in the area of ​​contact with the layers of the coating, without showing one or more defects according to the state techniques such as poor system solubility.

[0017] A further object of the invention was to provide rigid polyurethane or polyisocyanurate foams and underlying compositions which exhibit particularly advantageous performance properties such as, for example, good surface quality and / or low thermal conductivity.

[0018] Surprisingly, it has been found that the polyether siloxanes of formula (I) as described below and in the claims that hardly contain primary and, above all, secondary and / or tertiary OH groups, solve one or more of the above tasks. This was particularly surprising, as US 4,746,683 describes improving the openness of soft foam cells with high elasticity by using polyether siloxanes mainly with secondary or tertiary OH groups, while very high cell closure in rigid foams was achieved for the compound of formula (I).

[0019] The invention therefore relates to polyether siloxanes of formula (I) as described below and in the claims which hardly contain primary and, above all, secondary or tertiary OH groups, and the use of the polyether siloxanes of the invention for the production of polyurethane and polyisocyanurate foams.

[0020] Another object of the invention is a composition intended for the production of rigid polyurethane or polyisocyanurate foams containing at least one isocyanate component, at least one polyol component, at least one foam stabilizer, at least one urethane and / or isocyanurate catalyst, water and / or blowing agent, and optionally at least one flame retardant and / or other additives which is characterized by that as a foam stabilizer it contains at least one polyether siloxane according to the invention, a method for obtaining rigid polyurethane or polyisocyanurate foams by reacting this composition as well as rigid polyurethane or polyisocyanurate foams obtained in this way.

[0021] In addition, the invention relates to the use of rigid polyurethane or polyisocyanurate foams as insulation boards, insulating agents and in the form of metal composite elements as structural elements for the construction of buildings, cold stores, refrigerated containers and trucks as well as cooling apparatuses that contain polyurethane or polyisocyanurate rigid foam as insulating material.

[0022] The polyether siloxanes according to the invention have the advantage that they can be used to produce polyurethane or polyisocyanurate foams, in particular rigid foams, which have good fine-cellularity and good insulating properties and at the same time have few foam defects. In particular, problematic foam defects (shrinkage cavities, compaction) on the surface bordering the coating layer can be effectively minimized with the help of the polyether siloxanes of the invention relative to the state of the art, in particular with composite systems with flexible or rigid coating layers.

[0023] The polyether siloxanes, compositions and polyurethane foams of the invention as well as their uses are described below by way of example, the invention not being limited to these embodiments. If ranges, general formulas or classes of compounds are given, they are not intended to contain only the respective ranges or groups of classes of compounds that are mentioned in detail, but also all partial and partial ranges of groups of compounds that could be obtained by removing single values ​​(ranges) or relationships. As part of the following description, documents are cited whose content entirely belongs to the disclosure of this invention in particular with reference to the facts cited. If the mean values ​​are given below, then it refers to the numerical average unless stated otherwise.

[0024] The polyether siloxane according to the invention corresponds to formula (I),

R¹-Si (CH3) 2-O - [- Si (CH3) 2-O-] n - [- Si (CH3) RO-] m-Si (CH3) 2- R² (I) according to claim 1.

R '' 'can preferably be

- an alkyl residue of 1 to 40, preferably of 1 to 24 carbon atoms or

- an acyl residue of 1 to 40, preferably of 1 to 24 carbon atoms.

[0025] In formula (I) n + m + 2 may preferably be 12 to 100, more preferably 15 to 50 and most preferably 20 to 40.

Preferably in formula (I) at least 50%, particularly preferably 100% of the R "'residues are hydrogen, wherein all polyether R residues having an R" "= H end group, preferably at least 70%, contain a secondary or tertiary OH group, i.e. the terminal constituent alkyl oxide of R 'and / or R' 'is not -H.

[0027] According to the invention, the polyether siloxanes of formula (I) are copolymers which, for production reasons, are usually polydisperse compounds, so only average values ​​can be given for the parameters n, m, x and y.

[0028] The ratio of primary OH to secondary / tertiary groups can be influenced by the polyether used in the preparation and by the amount of capping reagent introduced. The ratio of primary OH groups to secondary and tertiary can be determined using NMR. Preferably, the assay is carried out as described below using an NMR spectrometer with a unit of calculation and an autosampler with a Bruker Type 400 MHz, 10 mm QNP tube head, and using both 5 mm tubes and plastic plugs from Norell Inc. Samples were taken using Brand's pastoral pipettes. The following reagents were introduced: deuterated chloroform (CDCl3) from Deutro, (99.8% deuteration rate), Merck A3 molecular sieve (to remove residual water from the solvent).

[0029] Measurements were carried out using the measurement parameters given in Table A.

Table A: Measurement parameters for NMR measurements

<td></td><td>¹1 H NMR</td><td>¹³C NMR</td>

<td>amount of sample</td><td>approx. 20 mg</td><td>approx. 1 g</td>

<td>volume of CDCl₃</td><td>approx. 1.25 ml</td><td>about 5 ml</td>

<td>frequency transmitter</td><td>399.87 MHz</td><td>100.565 MHz</td>

<td></td><td>¹1 H NMR</td><td>¹³C NMR</td>

<td>impulse</td><td> 8</td><td> 10</td>

<td>relaxation time</td><td>0 sec</td><td>10 seconds</td>

<td>shift frequency transmitter</td><td>1350.0 Hz</td><td>11000 Hz</td>

<td>measurement time</td><td> 16</td><td> 512</td>

<td>line width</td><td>0.1 Hz</td><td>1 Hz</td>

[0030] To this end, a specified amount of sample was introduced into a clean NMR tube and mixed with the specified amount of CDCl3. The test tube was closed with a plastic stopper and the sample was homogenised by shaking. After all the air bubbles had settled on the upper surface, the samples were measured on an NMR spectrometer. The assignment of individual signals is known to the person skilled in the art and can optionally take place by comparison with the signals for a particular exemplary substance. The evaluation in relation to the molar ratios of free OH groups (R '' = H) to OH groups terminally encapsulated (R '' does not mean H) is achieved by the fact that the appropriate signal integrals are placed in the ratio, which are assigned to the respective groups. It is known to those skilled in the art to include a so-called sample accelerator so as to ensure signal comparability. By measuring the model substance for which the molar ratio is known, the skilled person can determine the appropriate accelerator. A suitable accelerator is one for which the measured ratio from the actual ratio deviates by a maximum of 5%. As an accelerator, for example, chromoacetylacetonate can be used in a concentration of approx. 0.8% by mass based on the amount of sample.

[0031] The polyether substituents may advantageously be oriented on the siloxane chain in the comb (opposite) position (m equal to 0). In addition, polyether substituents may be available on the terminal silicon atoms of the siloxane chain (R¹ and R² = R).

[0032] The final group of polyether residues is either a free OH group, an alkylether (preferably methyl) group or an ester formed by esterifying OH groups with any carboxylic acid (preferably acetic acid). Part of the R '' residue may preferably be an alkyl residue, preferably only a methyl residue, however, it is important for the invention that on average (number average, averaged for all compounds of formula (I)) at least 25% of the polyethers contain terminal OH groups (i.e. R '' '= -H) and these OH groups mainly (at least 50%) were secondary or tertiary OH groups.

[0033] The alkylene oxide units described by the index y preferably relate to ethylene oxide, propylene oxide, n-butylene oxide, iso-butylene oxide and styrene oxide. The molar part of ethylene oxide is at least 45 mol-%. particularly preferably at least 65 mol-%.

[0034] The sequence of the different constituents of alkylene oxides can be arbitrary, apart from the terminal block with ethers with OH functional groups, i.e. they can be random or undergo a special block structure. For OH polyether residues, a two-block structure consisting of a pure ethylene oxide component and an alkylene oxide terminal component other than ethylene oxide may be particularly advantageous [0035] The polyether in one molecule may be similar or different, provided that the mixture polyether meets the above definition. In addition, mixtures of different polyether siloxanes are included, provided that the average value of the mixtures falls within the above range or the ingredient meets the above definition.

[0036] Particularly preferred polyether siloxanes according to the invention are those for which the average n + m + 2 is 15 to 100, x is 3 and y is 5 to 25 and R1 and R2 are type R polyether residues.

[0037] The polyether siloxanes of the invention can generally be obtained by methods of preparation of polysiloxanes known in the art.

[0038] The synthesis of the polyether siloxanes according to the invention preferably takes place in a reaction catalyzed by platinum from Si-H functional groups with unsaturated terminal polyethers. A detailed description is found in EP 1 520 870, which is incorporated by reference and is included in the disclosure of this invention. EP 0 493 836 describes the production of polyether modified siloxanes which are used in soft foams. Further examples of siloxane production are described e.g. in US 4,147,847 and US 4,855,379.

[0039] The precursors used in the so-called hydrosilylation reaction are available using a specific chemical method:

[0040] Siloxanes with Si-H functionalities can be obtained by reacting siloxanes free of Si-H functional groups, preferably e.g. hexamethyldisiloxane and decamethylcyclopentasiloxane with siloxanes with Si-H functional groups, preferably linear polyether ethylhydrosiloxanes such as HMS-993 by Gelest inc. And optionally linear α, ω-dihydrogenpolydimethylsiloxanes, such as 1,1,3,3-tetramethyldisiloxane, in an acid-catalyzed equilibrium reaction. The average product structure was determined by the ratio of raw materials introduced.

[0041] Terminal unsaturated polyethers can be obtained by reacting terminal unsaturated starting alcohols, preferably such as allyl alcohol, with various alkylene oxides, preferably with alkaline catalysis, for example with alkali hydroxides or with dimethyl cyanide catalysis (DMC). The sequence of the resulting polyether is therefore controlled by the dosage of the alkyl oxide. Thanks to this, block structures can be obtained in such a way that the alkyl oxide A binds to the starting alcohol and when complete conversion is achieved, the alkyl oxide B is added and it binds. By introducing the alkylene oxide A and B into the mixture, a statistical sequence can be obtained. When the desired sequences and molar masses are developed, the polyethers can, if desired, be subjected to either direct water treatment, whereby products with OH end groups will be obtained, or optionally undergo an additional reaction step for final capping, for example by reaction with methyl chloride during formation methyl ether end group using Williamson reaction. Thus, for example, EP 1 360 223 and the documents cited therein describe the preparation of olefin polyethers with and without derivatization of OH functional groups.

[0042] Various methods can be used to obtain the proportion of secondary or tertiary OH end groups of the invention. One possibility is, for example, that in the preparation of the polyether, a block consisting of on average 0.5 to 5, preferably 1 to 3, alkylene oxide segments per polyether molecule R 'and / or R' 'denoting -H is attached. Specific alkylene oxides for these end blocks are, for example, propylene oxide, butylene oxide, iso-butylene oxide and styrene oxide. [0043] In addition to the described end element, a variety of alkylene oxides can be used in addition to the polyethers with OH functionalities to obtain polyether residues, preferably ethylene oxide , propylene oxide, optionally butylene oxide and optionally styrene oxide. The components of the ethylene oxide raw materials averaged for all polyether residues for all molecules of formula (I) are preferably at least 45 mol-%, particularly preferably at least 65%. The sequence of the different constituents of alkylene oxides can be any, except for the terminal block with ethers with OH functional groups, i.e. they can be random or undergo a special block structure. This can be particularly advantageous for polyether residues with OH functional groups when a two-block structure is achieved, whereby a pure ethylene oxide element is first obtained and then an end element is attached to which an alkylene oxide other than ethylene oxide is then introduced.

[0044] The polyether siloxanes of the invention can be used for all known applications where polyether siloxanes can be incorporated. Preferably, the polyether siloxanes of the invention are used to prepare polyurethane foams, polyisocyanurate foams, in particular to obtain rigid polyurethane foams or rigid polyisocyanurate foams.

The composition according to the invention (usually divided into two components), suitable for the production of rigid polyurethane or polyisocyanurate foams, comprises at least one isocyanate component, at least one polyol component, at least one foam stabilizer, at least one urethane catalyst and / or isocyanurate, optionally water and / or blowing agent, and optionally at least one flame retardant and / or further additives, and is characterized by that as a foam stabilizer it contains at least one polyether siloxane according to the invention or also a polyether siloxane mixture which contains or consists of the polyether siloxane according to the invention. The composition according to the invention is divided into two or more components before processing, in such a way that the polyether siloxane according to the invention or also the mixture of polyether siloxanes is preferably not included in the component which contains isocyanate components.

[0046] The composition according to the invention relates to the mass parts of the polyether siloxane of the invention (as a foam stabilizer) with respect to 100 parts by mass of polyol components (pphp) preferably from 0.1 to 10 pphp, more preferably 0.5 to 5 pphp and particularly preferably from 1 to 3 pphp.

[0047] The composition of the invention may contain all isocyanate compounds suitable for making rigid polyurethane or polyisocyanurate foams. Preferably the composition of the invention contains one or more organic isocyanates with two or more isocyanate functional groups, such as, for example, 4,4'-diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI). Particularly suitable is a mixture known as "polymeric MDI" (crude MDI) from MDI and higher condensed analogues with an average functionality of 2 to 4, as well as various TDI isomers in pure form or as an isomeric mixture.

[0048] Suitable polyols within the meaning of this invention may be all organic substances with more isocyanate-reactive groups as well as their raw materials. Preferred polyols are all commonly used polyether polyols and polyester polyols for making polyurethane foams. Polyether polyols can be obtained by reaction with polyvalent alcohols or amines with alkylene oxides. Polyester polyols based on polyvalent carboxylic acid esters (which may be either aliphatic, for example adipic acid or aromatic for example phthalic acid or terephthalic acid) with polyvalent alcohols (mainly glycols).

[0049] The corresponding ratio of isocyanates and polyols, expressed as the formulation index, i.e. the stoichiometric ratio of isocyanate groups compared to reactive isocyanate groups (e.g. OH groups, NH groups) multiplied by 100 is in the range from 10 to 1000, preferably from 80 up to 350.

[0050] The composition of the invention as a urethane and / or isocyanuric catalyst preferably contains one or more catalysts for the polyol isocyanate and / or water isocyanate reaction and / or di- or trimerization of isocyanates. Typical examples of amines are triethylamine, dimethylcyclohexylamine, tetramethylethylenediamine, tetrametyloheksanodiamina, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, triethylenediamine, dimethylpiperazine, 1,2dimetyloimidazol, N-ethylmorpholine, tris (dimethylaminopropyl) hexahydro-1,3,5-triazine, dimethylaminoethanol, dimethylaminoethoxyethanol, and bis (dimethylaminoethyl ) tin compounds such as dibutyltin dilaurate or tin (II) 2-ethylenehexanoate and potassium salts such as potassium acetate and potassium 2-ethylenehexanoate.

[0051] Preferably the amounts of catalysts in the composition according to the invention depend on the type of catalyst and range from 0.05 to 5 pphp (= mass parts based on 100 mass parts polyol) or also 0.1 to 10 pphp for potassium salts .

[0052] The specific water content within the meaning of this invention depends on whether one or more blowing agents are additionally added to the water. For foams obtained from clean water, the values ​​are usually from 1 to 20 pphp, when with the addition of additional blowing agents, this value is usually reduced to from 0 to 5 pphp.

[0053] Additional blowing agents, which may be physical blowing agents or chemical blowing agents, are present in the composition of the invention. Preferably the composition contains physical blowing agents. Specific physical blowing agents within the meaning of this invention are gases, e.g. liquid CO2 and volatile liquids, e.g. hydrocarbons with 3 to 5 carbon atoms, preferably cyclo, iso-, and n-petnane, fluorocarbons, preferably HFC 245fa, HFC 134a and HFC 365mfc, fluorochlorohydrocarbons, preferably HCFC 141b, oxygen-containing compounds such as methyl formate, dimethoxymethane or chlorohydrocarbons, preferably 1,2-dichloroethane.

[0054] In addition to or in place of water and / or physical blowing agents, other chemical blowing agents that react with isocyanates with gas formation, such as formic acid, may also be introduced.

[0055] The composition of the invention as flame retardant may contain all flame retardant compounds suitable for preparing rigid polyurethane or polyisocyanurate foams. Suitable flame retardants in the context of this invention are preferably liquid organic phosphorus compounds such as halogen-free organic phosphates, e.g. triethyl phosphate (TEP), halogenated phosphates, e.g. tris (1-chloro-2-propyl) phosphate (TCPP) and tris (2-chloroethyl) phosphate (TCEP) and organic phosphonates, e.g. dimethylmethane phosphonate (DMMP), dimethylpropane phosphonate (DMPP), or solids such as ammonium phosphonate (APP ) or red phosphorus. Further suitable halogenated flame retardant compounds are, for example, halogenated polyols as well as solids such as porous graphite and melamine.

[0056] The method according to the invention for the production of rigid polyurethane or polyisocyanurate foams is distinguished in that the composition according to the invention described above is used. A summary of the state of the art, the raw materials used and the methods used can be found in Oertel (Hrsg.): "Kunststoffhandbuch", vol. VII, C. Hanser Verlag, Miinchen, 1983, in Houben-Weyl: "Methoden der organischen Chemie", volume E20, Thieme Verlag, Stuttgart 1987, (3), pages 1561 to 1757, and in "Ullmann's Encyclopedia of Industrial Chemistry" vol. A21, VCH, Weinheim, 4th Edition 1992, pages 665 to 715.

[0057] Rigid polyurethane or polyisocyanurate foams can be obtained by the composition according to the invention or also the method according to the invention.

[0058] A preferred composition, in particular a formulation for rigid polyurethane or polyisocyanurate foams in the context of this invention leads to rigid polyurethane or polyisocyanurate foam with a volumetric weight of 5 to 200 kg / m³, preferably from 5 to 50 kg / m³ and has the following composition:

Table 1: Typical rigid foam formulation

<td>Ingredient</td><td>Weight share</td>

<td>polyol</td><td> 100</td>

<td>amine catalyst</td><td>0.05 to 5</td>

<td>potassium trimerization catalyst</td><td>0 to 10</td>

<td>polyether siloxane of formula (AND)</td><td>0.5 to 5</td>

<td>water</td><td>0 to 20</td>

<td>blowing agent</td><td>0 to 40</td>

<td>flame retardant</td><td>0 to 50</td>

<td></td><td></td>

<td>isocyanate index: 80 to 350</td><td></td>

[0059] The composition according to the invention with a few exceptions is divided into two parts before processing, which must be mixed together for reacting. This can be achieved using all methods known to the person skilled in the art, for example, by means of a manual mixing process or preferably by means of a vacuum or overpressure foaming machine. Subsequently, discontinuous methods can be used, for example for the production of molded foams, refrigerators and panels, or continuous methods, for example, through insulation boards and metal composite components (in so-called dual-band processes), by blocks or by spraying methods.

[0060] A special case is 1- and 1.5-component cans. The composition according to the invention for this application is reacted already during the filling of the aerosol can, thereby forming a polyol prepolymer as well as from other reactive isocyanate-reactive components. This prepolymer is extracted from the aerosol can with propellants and cured by secondary crosslinking under the influence of humidity (from air). The polyether siloxanes of the invention can be used as foam stabilizers in this application.

[0061] The rigid polyurethane or polyisocyanurate foams of the invention can be made by the process of the invention. Preferably, rigid polyurethane foams or rigid polyisocyanurate foams contain from 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass and particularly preferably from 1 to 3 parts by mass with respect to 100 parts by mass of polyether siloxane polyol components of the invention in bound form and / or unbound.

[0062] Rigid polyurethane or polyisocyanurate foams can be used for the production of insulation boards and insulation agents or also insulation materials. In this way, refrigeration apparatuses, such as e.g. refrigerators or freezers, are available which are characterized in that the insulating material is rigid polyurethane or polyisocyanurate foam according to the invention.

[0063] Particularly preferred uses are described below which should not be limiting on the subject of the invention.

[0064] In a preferred embodiment of the invention, the compositions of the invention were used as PUR compositions (index below 200), which are used for foaming during a discontinuous process for the molds. Often these forms are dimensioned in such a way that the foaming mixture has a long flow path which increases the susceptibility to foam disturbances. By using this composition according to the invention, susceptibility to foam disturbances can be minimized.

[0065] It is preferred to use the compositions of the invention for the production of refrigerators or other refrigeration equipment. Therefore, in a discontinuous process, the foaming mixture is injected into the walls of the so-called cabinet (and separately in the door) and must fill the available space between the outer layer and the inner layer (inliner). Thus, the foam is subjected to flow stress, which increases the risk of defect formation. In addition, the materials used play an important role. The inliner consists mainly of plastic, and the outer shell of the refrigerator consists of a metal shell. At this point, there should be no foam defects that lead to interactions between materials or any contaminants originating therefrom. The composition according to the invention has a higher ability to prevent foam defects under these conditions. As a result, smooth surfaces of the refrigerator are also obtained by using thin outer layers, such as e.g. metal outer layers and / or outer plastic layers, for which the tendency to develop defects is limited to the boundary layer. The outer plastic layers can be outer polypropylene, polyethylene or high impact polystyrene HIPS (High Impact Polystyrene) layers.

[0066] In another preferred embodiment of the invention, the composition according to the invention is used to prepare composite elements. Thus, in this continuous process, the foam composition (PUR and PIR formulations are used) is injected between the two outer layers. Various materials are considered as coating layers. Metal coating layers are used to obtain metal composite elements, which are then used in the construction industry. They may also have plastic coatings on one or two sides. The composite elements obtained in this way, also called panels, can be used in various areas such as the construction industry (facades), in the automotive industry (motorhome industry), exhibition constructions (light walls) or for the production of furniture. Especially with double-sided plastic layers, very light composite materials can be obtained. For example, the following materials can be used as coating layers: PMMA (polymethylmethacrylate), HIPS (High Impact Polystyrene), PP (polypropylene), Resopal, fiber reinforced paper grades. Special problems may arise from coatings on metal layers or from auxiliary permeability (separation agents) in the processing of plastic surfaces, which can negatively affect the formation of foams. In general, the compositions of the invention show advantages in terms of the quality of the outer surfaces, where there are fewer foam defects than when using the prior art siloxanes. In addition to the aesthetic aspects, you can also improve the adhesion of the foam outer layers.

[0067] In further preferred embodiments, the compositions of the invention (or also the polyether siloxanes of the invention) were used to continuously prepare polyurethane or polyisocyanurate based on metal panels. The foam mixture was applied to the lower metal layer using a dual band laminator at a maximum band speed of 25 m / min through a traverse mixing head. Often, metal outer layers are also profiled. The laminator then reaches a mixture of the above outer layer, in which way a continuous metal panel is formed, which at the outlet end of the laminator is cut to the desired length.

[0068] The foam mixture must completely cover frequently profiled outer layers and completely fill the space between the layers. In most cases, the foam mixture is dosed from the mixing head, on which there are so-called casting harps. Using a founding harp, the mixture is applied from more holes along the direction of the strand. To achieve an even distribution of foam across the width of the panel, the mixing head moves in a traverse manner across the entire width of the panel. Another task is to avoid surface defects that can arise from metal layers (coil coating) because they often contain anti-foaming agents that can be detrimental to foam or foaming. In general, the compositions of the invention show advantages in terms of the quality of the outer surfaces, where there are fewer foam defects than when using the prior art polyether siloxanes.

[0069] In further preferred embodiments, compositions of the invention (siloxanes) have been used to continuously prepare panels based on polyurethane or polyisocyanurate with flexible outer layers. The foam mixture was applied to the outer layer using a dual-band laminator at a band speed of up to 50 m / min through one or more mixing heads. The laminator then achieves a growing mixture of the above outer layer, in which way a continuous panel is formed, which at the outlet end of the laminator is cut to the desired length.

[0070] It can therefore be applied to many different coating layers, such as, for example, paper, aluminum, bitumen, leveled fibers, multilayer films of various materials, etc.

[0071] Thus, the foam mixture must be distributed as evenly as possible as soon as possible due to its high bandwidth speed, so that a homogeneous foam can be formed without the densities and irregular cell size distribution. Due to the high amounts of application required here, devices with more than one head can also be used, in which case the foam mixture is applied in a greater number of strands in the laminator. This process is also referred to as "finger lay down".

[0072] The very diverse properties of the outer layer materials pose an additional challenge that may occur depending on the material, such as, for example, anti-foaming effects due to contamination on the outer coatings, poor adhesion, increased flow stress on very rough surfaces. Here, the prevention of surface defects comes first. In general, the compositions of the invention show advantages in terms of the quality of the outer surfaces, where there are fewer foam defects than when using the prior art polyether siloxanes.

[0073] This invention is explained in more detail on the basis of the figures without being limited thereto. Figures 1a to 1c show the formation of foams which were produced by using the polyether siloxanes of the invention (Figure 1a) or by using prior art polyether siloxanes (Figures 1b and 1c).

[0074] In the examples given below, the invention is described by means of examples, however, the invention, the fields of application of which are given throughout the description and in the claims, should not be limited to the so-called embodiments specified in the examples.

<a name="caption1"></a>Examples:

Example 1: Preparation of the polyether siloxanes of the invention [0075] The polyether siloxanes listed in Table 2 were obtained. The information in Table 2 is based on formula (I). The structural description of the polyether R residue gives the sequence of the resulting alkylene oxide segments corresponding to the sequential addition of alkylene oxide during the production of polyether controlled block sequences.

Table 2: Polyether siloxanes prepared according to the invention

<td>name</td><td>n + m + 2</td><td>m</td><td>R¹, R²</td><td>polyether residues R</td>

<td>PES I *</td><td> 40</td><td> 5</td><td>CH3</td><td>- (CH₂) 3-O- (CH₂CH₂O) 10 (CH₂-CH (CH3) -O)₂-H</td>

<td>PES II</td><td> 40</td><td> 3</td><td>-R</td><td>- (CH2) 3-O- (CH2-CH (CH3) -O) 4- (CH2-CH2-O) 12- (CH2CH (CH3) -O) 2-H</td>

<td>PES III</td><td> 40</td><td> 3</td><td>-R</td><td>- (CH2) 3-O- (CH2-CH2-O) 10- (CH2-C (CH3) 2-O) 1,5-H</td>

<td>name</td><td>n + m + 2</td><td>m</td><td>R¹, R²</td><td>polyether residues R</td>

<td>PES IV *</td><td> 60</td><td> 8</td><td>CH3</td><td>60 mole%: - (CH₂&gt; - O- (CH₂CH₂O) 10 (CH₂CH (CH3) O) 2 -H 40 mole%: - (CH₂) 3-O- (CH2-CH₂O) 12-CH3</td>

<td>PES V *</td><td> 30</td><td> 3</td><td>CH3</td><td>- (CH2) 3-O- (CH2-CH (CH3) -O) 4- (CH2-CH2-O) 12- (CH2-CH (CH3) -O) 2-H</td>

<td colspan="5">* not according to the invention</td>

[0076] The following examples 1a to 1c describe an exemplary preparation of PES polyethersiloxane. All other polyethersiloxanes from table 2 were obtained by reactions in analogous methods.

Example 1a: Synthesis of PES I, production of Si-H functional siloxanes [0077] Mixture with 244.7 g decamethylcyclopentasiloxane (D5), 31.7 g poly (methyl) hydrogen siloxane PTF1 (SiH content 15.75 Val / kg) and 14.5 g hexamethyldisiloxane (HMDS) was reacted analogously to example 1 of EP 1439200 (0.66 mole D5: 0.0104 mole PTF1: 0.0896 mole HMDS).

Example 1b: PES I Syneza, production of unsaturated polyethers [0078] Preparation of allyl polyethers is analogous to the method described in example 1 of document DE 19940797, where 58.0 g (1 mol) of alkyl alcohol as starter and 7.0 g (0.1 mole) potassium methylate, and 440.5 g (10 moles) of ethylene oxide were measured and after complete conversion a further 116.2 g (2 moles) of propylene oxide. For further processing, the procedure was analogous to Example 1 of DE 19940797.

Example 1c: PES I synthesis, hydrosilylation [0079] The hydrosilylation reaction (reaction of siloxanes with Si-H functional groups of siloxanes with allyl polyethers) was carried out according to example 1 of EP 1 520 870. To this end, 291.0 g (0.1 mol) The siloxanes of example 1a were reacted with 430.3 g (0.7 mol) of the polyether of example 1b.

Example 2: Embodiments [0080] Technical and application advantages with respect to the prior art that allow the use of the polyether siloxanes of the invention in rigid foam formulations are set out below based on embodiments.

[0081] Comparative foaming was carried out by manual mixing methods. For this purpose, a polyol, a flame retardant, catalysts, water, conventional or foam foam stabilizers and a blowing agent were introduced into the beaker and mixed with a disk mixer (diameter 6 cm) 30 s at 1000 rpm. When weighed again, the amount of blowing agent which was evaporated during the mixing process was determined. Then added

MDI, the reaction mixture was stirred with the described stirrer for 5 s at 3000 rpm and immediately transferred to a thermostated aluminum mold covered with polyethylene film. The temperature and geometry of the mold varied depending on the foam formulation. The amount of foam formulation used was estimated so that the necessary amount was 15% above the minimum filling capacity.

[0082] The foam was analyzed one day after foaming. The outer surface and internal disorders were subjectively assessed on a scale of 1 to 10, with 10 being undisturbed foam and 1 being strongly disturbed foam. The pore structure (average number of cells per 1 cm) was optically evaluated on the cut surface by comparison with comparative foams. The thermal conductivity coefficient was measured on 2.5 cm thick slices in a Hesto Lambda control apparatus at a temperature of 10 to 36 ° C on the lower and upper test side. The percent volume of closed cells was determined using AccuPyc 1330 devices from Micrometrics. The compressive strength of the foams was measured on cube-shaped test specimens with a side length of 5 cm in accordance with DIN 53421, up to 10% upset (it is given in this measuring range for the maximum compressive stress).

Example 2a: PUR rigid foam system for insulation of refrigerators [0083] For this application, a specific formulation (see Table 3) was used, which was foamed with three polyether siloxane foam stabilizers (PES I, PES II and PES III) respectively and two polyether siloxane foam stabilizers not subject of this invention (Tegostab B 1048, polyethersiloxane with a butyl-tipped tip without free OH groups and Tegostab B 8408, polyethersiloxane with OH functions, which are only primary OH groups in over 60%, both from Evonik Goldschmidt GmbH). The reaction mixture was introduced into an aluminum mold measuring 145 cm x 14.5 cm x 3.5 cm thermostated at 45 ° C.

Table 3: Formulation of Example 2a

<td>Ingredient</td><td>Weight share</td>

<td>Daltolac R 471 *</td><td>100 parts</td>

<td>N, N-dimethylcyclohexylamine</td><td>1.5 parts</td>

<td>water</td><td>2.6 parts</td>

<td>cyclo-pentane</td><td>13.1 parts</td>

<td>polyether siloxane</td><td>1.5 parts</td>

<td></td><td></td>

<td>Desmodur 44V20L **</td><td>198.5 parts</td>

<td>* Huntsman polyether polyol</td><td></td>

<td colspan="2">** polymeric MDI from Bayer, 200 mPa * s, 31.5 wt. NCO, functionality 2.7</td>

[0084] The results given in Table 4 show that the polyether siloxanes of the invention without exception lead to rigid foams with a lower thermal conductivity than those obtained from the prior art polyether siloxanes. For PES II and PES III, the disturbance of the external foam surface is much lower than when using comparative stabilizers.

<td colspan="2">Table 4: Results</td><td colspan="3">for insulation of refrigerators</td>

<td>stabilizer</td><td>defects up / down / inside (110)</td><td>cell / cm</td><td>λ value [mW / m * K]</td><td>Closure of cells [%]</td>

<td>PES I *</td><td> 7/6/6</td><td> 40-44</td><td> 22,1</td><td> 94</td>

<td>PES II</td><td> 8/7/6</td><td> 40-44</td><td> 22,3</td><td> 91</td>

<td>PES III</td><td> 8/7/6</td><td> 40-44</td><td> 22,2</td><td> 90</td>

<td>B 1048 *</td><td> 7/6/6</td><td> 35-39</td><td> 22,7</td><td> 92</td>

<td>B 8408 *</td><td> 7/6/5</td><td> 35-39</td><td> 23,2</td><td> 89</td>

<td colspan="5">* comparative examples not according to the invention; TEGOSTAB B 1048 and TEGOSTAB B 8408 are polyether siloxane foam stabilizers from Evonik Goldschmidt GmbH</td>

Example 2b: PUR rigid foam system for metal-related components [0085] A specific formulation (see Table 5) was used for this application, which was foamed respectively with the polyether siloxane foam stabilizer (PES IV) according to the invention and two polyether siloxane foam stabilizers not being the subject of this invention (Tegostab B 8443, polyether siloxane with a completely capped end without free OH groups and Tegostab B 8486, polyether siloxane with OH functions, which are only primary OH groups, both from Evonik Goldschmidt GmbH). The reaction mixture was introduced into an aluminum mold measuring 50 cm x 50 cm x 5 cm thermostated at 40 ° C, which was previously lined on a steel sheet. The next day, the foam sheet was removed and the foam was then evaluated.

<td>Table 5: Formulation for metal cellular components</td><td>pozytowych</td>

<td>Ingredient</td><td>Weight share</td>

<td>blend of polyether polyols</td><td>70 parts</td>

<td>tris (1-chloro-2-propyl) phosphate</td><td>30 parts</td>

<td>N, N, N ', N ", N" -pentametylodietylenotriamina</td><td>0.2 parts</td>

<td>N, N-dimethylcyclohexylamine</td><td>2.0 parts</td>

<td>Ingredient</td><td>Weight share</td>

<td>water</td><td>2.5 parts</td>

<td>n-pentane</td><td>6.0 parts</td>

<td>polyether siloxane</td><td>2.0 parts</td>

<td>Desmodur 44V20L **</td><td>140 parts</td>

<td colspan="2">** polymeric MDI from Bayer, 200 mPa * s, 31.5 wt. NCO, functionality 2.7</td>

[0086] The results presented in Table 6 show that the PES IV polyether siloxane gives even lower thermal conductivity than the other two comparative stabilizers not subject to the invention. After removing the top layer of foam, foam defects below were visible from the bottom of the foam. Fig. 1a is a photograph of the upper surface obtained by using PES IV polyether siloxanes. FIG. 1b and 1c show photos of the upper surface obtained by using polyether siloxanes B 8443 (Fig. 1b) and B 8486 (Fig. 1c) which are not examples of the invention.

[0087] Polyether siloxane PES IV gives a clear reduction in the formation of shrinkage cavities and therefore gives a better surface quality than comparative products.

<td colspan="2">Table 6: Results of d</td><td colspan="3">la metal composites</td>

<td>stabilizer</td><td>defects up / down / inside (110)</td><td>cell / cm</td><td>λ value [mW / m * K]</td><td>Closure of cells [%]</td>

<td>PES IV *</td><td> 7/**/8</td><td> 45-50</td><td> 22,0</td><td> 91</td>

<td>B 8443 *</td><td> 7/**/8</td><td> 45-50</td><td> 22,3</td><td> 94</td>

<td>B 8486 *</td><td> 7/**/7</td><td> 40-44</td><td> 23,0</td><td> 93</td>

<td colspan="5">* comparative examples not according to the invention; TEGOSTAB B 8443 and TEGOSTAB B 8486 are polyether siloxane foam stabilizers from Evonik Goldschmidt GmbH</td>

<td colspan="2">** foam quality from the bottom side after pictures</td><td colspan="3">and the sheets are shown in Figures 1a to 1c.</td>

Example 1c: PIR rigid foam system for insulation board [0088] For this application, a specific formulation (see Table 7) was used, which was foamed with polyether siloxane foam stabilizer (PES V) and two polyether siloxane foam stabilizers not subject of this invention, respectively (Tegostab B 1048, polyether siloxane end capped butyl without free OH groups and Tegostab B 8466, polyether siloxane with OH functional groups, which are only primary OH groups, both from Evonik Goldschmidt GmbH). The reaction mixture was introduced into an aluminum mold measuring 50 cm x 25 cm x 5 cm thermostated at 50 ° C.

Table 7: Formulation for insulation board

<td>Ingredient</td><td>Weight share</td>

<td>Stepanpol PS 2352 *</td><td>100 parts</td>

<td>tris (1-chloro-2-propyl) phosphate</td><td>15 parts</td>

<td>N, N, N ', N ", N" pentamethylenediyl enetriamine</td><td>0.2 parts</td>

<td>potassium octoate (75% by weight in diethylene glycol)</td><td>4.0 parts</td>

<td>water</td><td>0.4 parts</td>

<td>n-pentane</td><td>20 parts</td>

<td>polyether siloxane</td><td>2.0 parts</td>

<td>Desmodur 44V20L **</td><td>200 parts</td>

<td colspan="2">* Stepan polyester polyol ** polymeric MDI from Bayer, 200 mPa * s, 31.5 wt. NCO, functionality 2.7</td>

[0089] The results presented in Table 8 show once again that when using PES V polyether siloxanes, the foams obtained show lower thermal conductivity and better foam quality on the underside than foams obtained using comparative products not of the invention.

Table 8: Results for insulation boards

<td>stabilizer</td><td>defects up / down / inside (110)</td><td>cell / cm</td><td>λ value [mW / m * K]</td><td>Closure of cells [%]</td>

<td>PES V *</td><td> 6/8/8</td><td> 45-50</td><td> 22,5</td><td> 94</td>

<td>B 1048 *</td><td> 6/7/8</td><td> 45-50</td><td> 23,0</td><td> 92</td>

<td>B 8466 *</td><td> 6/7/8</td><td> 45-50</td><td> 22,8</td><td> 94</td>

<td colspan="5">* comparative examples not according to the invention; TEGOSTAB B 1048 and TEGOSTAB B 8466 are polyether siloxane foam stabilizers from Evonik Goldschmidt GmbH</td>

Magdalena Pietrosiuk Patent Attorney