Method for producing SiOC-linked linear polydialkylsiloxane-polyether block copolymers and use thereof

Abstract

The invention relates to a method for producing SiOC-linked linear polydialkylsiloxane-polyoxyalkylene block copolymers having repeating (AB) units, comprising the reaction of a linear alpha, omega-(SiH) functional polydialkylsiloxane (a) with a linear alpha, omega-(OH) functional polyoxyalkylene (b), one or more compounds of elements of the third main group and / or the third sub-group are used as catalyst (c), the two reactants (a) and (b) are preferably reacted in equimolar amounts and have a controlled hydrogen formation reaction up to a quantitative SiH conversion.

Description

[0001] The present invention belongs to the field of organosilicon chemistry and polyurethane chemistry and relates to a process for preparing SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymers containing repeating (AB) units, and their use in the preparation of polyurethanes (abbreviated as PU).

[0002] The principle of a process for producing SiOC-bonded polydialkylsiloxy-polyoxyalkylene block copolymers by reacting SiH-functional polyorganosiloxanes with alcohol / OH-functional polyoxyalkylene polymers using one or more compounds of elements of main group III and / or transition group III as catalysts is known in principle from EP 1 460 099 B1. The preferred reaction of at least an equimolar to 3-fold excess of alcohol groups with SiH groups is described therein. The process is used to react linear and / or branched polyorganosiloxanes with alcohols and / or OH-functional polyoxyalkylenes.

[0003] A process for preparing SiOC-bonded linear polydimethylsiloxane-polyether block copolymers containing repeating (AB) units is also known from EP 1935922 B1, wherein the polydimethylsiloxane-polyoxyalkylene block copolymers prepared in this way are used as interface-active additives for the preparation of polyurethane foams. EP 1935922 B1 describes the reaction of linear α,ω-(SiH)-functional polydimethylsiloxanes containing linear α,ω-(OH)-functional polyether diols using one or more compounds of elements of main group III and / or transition group III as catalysts. The process, which can be carried out in pure form or in the presence of a solvent, has the following essential features: the (SiH) functional groups of the polydimethylsiloxane are used in a molar excess of preferably 1.1 to 2.0 relative to the (OH) functional groups of the polyoxyalkylene, and the reaction is continued until the (SiH) groups can no longer be detected by a gas volume device.

[0004] However, the use of excess polysiloxanes which are much more expensive than the polyetherdiol component and the subsequent lengthy afterreaction for the quantitative reaction of the excess (SiH) groups are disadvantageous from an economic point of view.

[0005] The object of the present invention was therefore to provide a simple, economically viable and stable process which makes it possible to reproducibly produce SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymers comprising repeating (AB) units and having an improved property profile, preferably focusing on their use as interface-active additives for the production of polyurethane foams, in particular for the production of rigid polyurethane foams.

[0006] It has now been found that, surprisingly, the use of preferably equimolar amounts of (SiH) functional groups of linear α,ω-(SiH)-functional polydiorganosiloxanes relative to (OH) functional groups of linear α,ω-(OH)-functional polyoxyalkylenes in combination with controlled hydrogen release according to claim 1 makes it possible to provide particularly high molecular weight products, which represent a higher quality product than that obtainable by the process disclosed in EP 1 935 922 B1. Controlled hydrogen release can be achieved by controlled feed amounts. In addition, the process according to the invention is significantly more stable and less prone to failure.

[0007] The present invention provides a process for preparing SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymers comprising repeating (AB) units, which comprises reacting a linear α,ω-(SiH)-functional polydialkylsiloxane (a) with a linear α,ω-(OH)-functional polyoxyalkylene (b), optionally in the presence of a solvent (d), using one or more compounds of elements of main group III and / or of the third transition group as catalyst (c), wherein the two reactants (a) and (b) are preferably reacted in equimolar amounts and with controlled hydrogen release until the SiH conversion is quantitative.

[0008] In the context of the present invention, reactant (a) is: a linear α,ω-(SiH)-functional polydialkylsiloxane.

[0009] In the context of the present invention, reactant (b) is: a linear α,ω-(OH)-functional polyoxyalkylene.

[0010] In a particularly preferred embodiment of the present invention, the linear α,ω-(SiH)-functional polydialkylsiloxane used in the process according to the invention has an SiH value of 0.25 to 3.0 mol / kg, more preferably 0.5 to 2.0 mol / kg, in particular 0.75 to 1.5 mol / kg. The determination of the molar amount of SiH units of the linear α,ω-(SiH)-functional polydialkylsiloxane is based on the known method of base-catalyzed SiH value determination.

[0011] The present invention further provides SiOC-bonded linear polydialkylsiloxane-polyether block copolymers comprising repeating (AB) units prepared by the process according to the invention.

[0012] The expressions “SiOC-bonded linear polydialkylsiloxane-polyether block copolymer” and “SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymer” are used synonymously in the context of the present invention.

[0013] The invention also provides the use of SiOC-bonded linear polydialkylsiloxane-polyether block copolymers containing repeating (AB) units as interface-active additives, in particular as cell openers, which copolymers are prepared by the process of the invention for the preparation of polyurethane foams (PU foams), preferably rigid polyurethane foams, in particular rigid polyurethane foams with a high open cell content. Particularly preferred rigid polyurethane foams are one-component canned PU foams (building foams, assembly foams, one-component foams / OCF). Particularly preferred are rigid polyurethane foams in which a high cell content is advantageous, such as open-cell spray foams, packaging foams, roof lining foams, pipe insulation foams, flower-shaped foams and / or thermoformable rigid foams, etc.

[0014] The present invention also provides polyurethane foams, preferably rigid polyurethane foams, in particular rigid polyurethane foams with a high open cell content, produced using the SiOC-bonded linear polydialkylsiloxane-polyether block copolymers according to the invention comprising repeating (AB) units.

[0015] The present invention also provides the use of the polyurethane foams according to the invention, preferably rigid polyurethane foams, in particular rigid polyurethane foams with a high open-cell content, for producing foam moldings, spray foams, insulating foams, sealing compounds, adhesive compounds, insulation compounds, assembly compounds and / or filling compounds.

[0016] Attached Figures 1 to 6 A brief description:

[0017] Figure 1 Shown is the progression of the volume of gas released through the course of the reaction as a function of the mass of siloxane added from experimental example 1, in each case as target and actual conversion.

[0018] Figure 2 Shown is the progression of the volume of gas released through the course of the reaction as a function of the mass of siloxane added from experimental example 2, in each case as target and actual conversion.

[0019] Figure 3 Shown is the progression of the volume of gas released through the course of the reaction as a function of the mass of siloxane added from experimental example 3, in each case as target and actual conversion.

[0020] Figure 4 Shown is the progression of the volume of gas released through the course of the reaction as a function of the mass of siloxane added from experimental example 4, in each case as target and actual conversion.

[0021] Figure 5Shown is the progression of the volume of gas released through the course of the reaction as a function of the mass of siloxane added from experimental example 5, in each case as target and actual conversion.

[0022] Figure 6 The difference between the target conversion and the actual conversion (%) is shown as a function of the mass of added siloxane for Examples 1 to 5 from the experiments.

[0023] The linear α,ω-(SiH)-functional polydialkylsiloxanes used in the process according to the invention are known per se. They can be equilibrated in a known manner (preferably acidic) by any desired prior art methods.

[0024] They preferably have a weight-average molecular weight of about 650-7000 g / mol, preferably 1000-6000 g / mol, in particular about 1500-4500 g / mol. This corresponds to a preferred embodiment of the present invention. The determination of the average molecular weight is based on known GPC analysis methods.

[0025] Preference is given to using linear α,ω-(SiH)-functional polydialkylsiloxanes of the general formula (I):

[0026] M'-D a -M'Formula (I)

[0027] in

[0028] M'=[HR 1 2SiO 1 / 2 ]

[0029] D=[R 1 2SiO 2 / 2 ]

[0030] a=8-100, preferably 10-60, more preferably 20-50,

[0031] R 1 On each occurrence it is independently identical or different hydrocarbon radicals having 1 to 20 carbon atoms, preferably methyl, ethyl, propyl or butyl, particularly preferably methyl.

[0032] Linear α,ω-(OH)-functional polyoxyalkylenes (hereinafter also referred to as "polyether diols" for the purposes of the present invention) are likewise known per se. They can be produced by any desired prior art processes. They preferably conform to the general formula (II):

[0033] HO-(C n H( 2n-m )R 2 m O-) b -H formula (II)

[0034] b=1-200, preferably 10-100, particularly preferably 25-60,

[0035] n=2-4,

[0036] m = 0 or 1,

[0037] R 2 = is independently at each occurrence identical or different hydrocarbon radicals having 1 to 12 carbon atoms, preferably methyl, ethyl, propyl or butyl, particularly preferably methyl or ethyl.

[0038] It is preferred when the polyetherdiol is an addition product of at least one alkylene oxide selected from ethylene oxide, propylene oxide, butylene oxide, dodecene oxide and / or tetrahydrofuran onto a difunctional starter such as water, ethylene glycol or propylene glycol.

[0039] The polyetherdiol is preferably composed of at least two monomer units, particularly preferably of ethylene oxide and propylene oxide.

[0040] The polyether diols preferably consist essentially of ethylene oxide units or propylene oxide units, preference being given to mixed ethylene oxide and propylene oxide units, the ethylene oxide proportion being about 25 to 70% by weight and the propylene oxide proportion being 70 to 25% by weight, based on the total content of ethylene oxide units in the block.

[0041] Thus, the ethylene oxide units or propylene oxide units may have a random or block configuration, preferably a block configuration.

[0042] The weight average molecular weight M of each polyether diol w Preference is given to about 600 to 10,000 g / mol, preferably 1,000 to 5,000 g / mol, particularly preferably 1,500 to 3,500 g / mol. The determination of the average molecular weight is based on the known method for determining the OH number.

[0043] The molar ratio of linear α,ω-(SiH)-functional polydialkylsiloxane to linear α,ω-(OH)-functional polyoxyalkylene preferably used in the process according to the invention is in the equimolar range. This means that the (SiH)-functionality of the linear α,ω-(SiH)-functional polydialkylsiloxane is preferably used in an equimolar amount relative to the (OH)-functionality of the linear α,ω-(OH)-functional polyoxyalkylene.

[0044] When in the context of the present invention, reference is made to an equimolar ratio or equimolar amounts of the two reactants (a) and (b), this in the context of the present invention very specifically encompasses a range of 0.9 to 1.10, preferably 0.98 to 1.02, of α,ω-(SiH)-functional polydialkylsiloxane to linear α,ω-(OH)-functional polyoxyalkylene. The ratio is in particular very precisely equimolar, i.e. 1 to 1.

[0045] The total siloxane block (A) content in the SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymer having repeating (AB) units is preferably 20-60% by weight, in particular 40-50% by weight, and the proportion of polyoxyalkylene blocks (B) is preferably 80-40% by weight, preferably 60-50% by weight. When the block copolymer has an average weight average molecular weight M of at least 10,000 g / mol to about 250,000 g / mol, preferably 15,000 g / mol to about 225,000 g / mol, in particular 20,000 g / mol to about 200,000 g / mol, w The determination of the average molar mass is based on a known GPC analysis method.

[0046] Depending on the application and desired product properties, the process can be carried out in the presence or absence of a solvent as desired.

[0047] The use of solvents is particularly advantageous if SiOC-bonded copolymers of particularly high molecular weight and therefore particularly high viscosity are to be produced.

[0048] Advantageously usable solvents are, for example, alkanes, isoalkanes, cycloalkanes and / or alkylaromatics.

[0049] Advantageously, alkanes which can be used are, for example, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane and / or n-dodecane.

[0050] Advantageously, cycloalkanes which can be used are, for example, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane and / or decalin.

[0051] Advantageously, the alkylaromatic compounds which can be used are toluene, xylene, cumene, n-propylbenzene, ethylmethylbenzene, trimethylbenzene, solvent naphtha and / or any alkylbenzene which is available on an industrial scale.

[0052] High-boiling solvents which can preferably be used are those having a boiling point >120° C., particular preference being given to high-boiling alkylbenzenes.

[0053] The choice and amount of the optional solvent depends on the specific application and can vary within wide ranges.

[0054] For particularly good product quality and particularly good efficiency in a preferred embodiment of the invention, preference is given to using 40 to 75% by weight of solvent, based on the sum of the amounts of reactants (a), (b) and solvent (c), particularly preferably 55 to 65% by weight.

[0055] In the context of the preferred embodiments, the reaction temperature for the preparation of the block copolymers according to the invention is preferably from 60°C to 140°C, particularly preferably from 100°C to 120°C.

[0056] In the context of a preferred embodiment of the present invention, catalysts which are preferably usable in the process according to the invention are Lewis acid compounds of elements of main group III, in particular compounds containing boron and / or aluminum elements.

[0057] Preferred Lewis acid compounds of elements of the third transition group are in particular Lewis acids containing scandium, yttrium, lanthanum and / or lanthanide. Compounds of elements of main group III and / or the third transition group can more preferably be used in the form of halides, alkyl compounds, fluorinated, alicyclic and / or heterocyclic compounds.

[0058] Preferred embodiments of the present invention provide that fluorinated and / or non-fluorinated organoboron compounds are used as catalysts, in particular those selected from the group consisting of: (C5F4)(C6F5)2B; (C5F4)3B; (C6F5)BF2; BF(C6F5)2; B(C6F5)3; BCl2(C6F5); BCl(C6F5)2; B(C6H5)(C6F5)2; B(Ph)2(C6F5); [C6H4(mCF3)]3B; [C6H4(pOCF3)]3B; (C6F5)B(OH)2; (C6F5)2BOH; (C6F5)2BH; (C6F5)BH2; (C7H 11 )B(C6F5)2;(C8H 14 B) (C6F5); (C6F5)2B(OC2H5); (C6F5)2B-CH2CH2Si(CH3)3.

[0059]

[0060]

[0061] In particular, tris(perfluorotriphenylborane) [1109-15-5], boron trifluoride etherate [109-63-7], borane triphenylphosphine complex [2049-55-0], triphenylborane [960-71-4], triethylborane [97-94-9] and boron trichloride [10294-34-5], tris(pentafluorophenyl)cyclotriboroxane (9Cl) [223440-98-0], 4,4,5,5-tetramethyl-2-(pentafluorophenyl)-1,3,2-dioxaborolane (9Cl) )[3,2,2,4,2-81-2], 2-(pentafluorophenyl)-1,3,2-dioxaborolane (9Cl)[336880-93-4], bis(pentafluorophenyl)cyclohexylborane[24455-00-3], di-2,4-cyclopentadien-1-yl(pentafluorophenyl)borane(9Cl)[336881-03-9], (hexahydro-3a(1H)-pentacyclopentadienyl)bis(pentafluorophenyl)borane(9Cl)[336880-98-9], 1,3-[2-[bis(pentafluorophenyl)cyclohexylborane phenyl)boryl]ethyl]tetramethyldisiloxane [336880-99-0], 2,4,6-tris(pentafluorophenyl)borazine (7Cl,8Cl,9Cl) [1110-39-0], 1,2-dihydro-2-(pentafluorophenyl)-1,2-azaborole (9Cl) [336880-94-5], 2-(pentafluorophenyl)-1,3,2-benzodioxaborole (9Cl) [336880-96-7], tris(4-trifluoromethoxyphenyl)borane [336880- 95-6], tris(3-trifluoromethylphenyl)borane[2455-00-3], tris(4-fluorophenyl)borane[47196-74-7], tris(2,6-difluorophenyl)borane[14655-09-1], tris(3,5-difluorophenyl)borane[154735-09-8], methylium triphenyl tetrakis(pentafluorophenyl)borate[136040-19-2] and / or N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, and mixtures of the above catalysts can be preferably used.

[0062] In another preferred embodiment of the present invention, fluorinated and / or unfluorinated organoaluminum compounds are used as catalysts, in particular those selected from the group consisting of:

[0063] AlCl3 [7446-70-0], aluminum acetylacetonate [13963-57-0], AlF3 [7784-18-1], aluminum trifluoromethanesulfonate [74974-61-1], diisobutylaluminum chloride [1779-25-5], diisobutylaluminum hydride [1191-15-7] and / or triethylaluminum [97-93-8] and mixtures thereof.

[0064] In another preferred embodiment of the present invention, fluorinated and / or unfluorinated organoscandium compounds are used as catalysts, in particular those selected from the group consisting of:

[0065] Scandium (III) chloride [10361-84-9], scandium (III) fluoride [13709-47-2], scandium (III) hexafluoroacetylacetonate [18990-42-6], scandium (III) trifluoromethanesulfonate [144026-79-9] and / or scandium tris(cyclopentadienyl) [1298-54-0] and mixtures thereof.

[0066] In another preferred embodiment of the present invention, fluorinated and / or unfluorinated organoyttrium compounds are used as catalysts, in particular those selected from the group consisting of:

[0067] Yttrium tris(cyclopentadienyl)[1294-07-1], yttrium(III) chloride[10361-92-9], yttrium(III) fluoride[13709-49-4], yttrium(III) hexafluoroacetylacetonate[18911-76-7] and / or yttrium(III) naphthenate[61790-20-3] and mixtures thereof.

[0068] In a further preferred embodiment of the present invention, fluorinated and / or unfluorinated organolanthanide compounds are used as catalysts, in particular those selected from the group consisting of:

[0069] Lanthanum (III) chloride [10099-58-8], lanthanum (III) fluoride [13709-38-1], lanthanum (III) iodide [13813-22-4], lanthanum (III) trifluoromethanesulfonate [52093-26-2] and / or tri(cyclopentadienyl)lanthanum [1272-23-7] and mixtures thereof.

[0070] In another preferred embodiment of the present invention, fluorinated and / or unfluorinated organolanthanide compounds are used as catalysts, in particular those selected from the group consisting of:

[0071] Cerium (III) bromide [14457-87-5], Cerium (III) chloride [7790-86-5], Cerium (III) fluoride [7758-88-5], Cerium (IV) fluoride [60627-09-0], Cerium (III) trifluoroacetylacetonate [18078-37-0], Tri(cyclopentadienyl)cerium [1298-53-9], Europium (III) fluoride [13765-25-8], Europium (II) chloride [13769-20-5], Praseodymium (III) hexafluoroacetylacetonate [47814-20-0], Praseodymium (III) fluoride )[13709-46-1], praseodymium(III) trifluoroacetylacetonate[59991-56-9], samarium(III) chloride[10361-82-7], samarium(III) fluoride[13765-24-7], samarium(III) cyclohexaneate[61790-20-3], samarium(III) trifluoroacetylacetonate[23301-82-8], ytterbium(III) fluoride[13760-80-8], ytterbium(III) trifluoromethanesulfonate[54761-04-5] and / or ytterbium tris(cyclopentadienyl)[1295-20-1] and mixtures thereof.

[0072] The catalyst is preferably used in an amount of 0.01 to about 0.2% by weight, in particular 0.03 to 0.10% by weight, based on the sum of the amounts of reactants (a) and (b).

[0073] The catalyst can be used in the form of a homogeneous catalyst or a heterogeneous catalyst. The catalyst can be added in a dissolved or suspended form. The catalyst can be advantageously suspended or dissolved in a small portion of a solvent or polyether diol and added, and can particularly preferably be dissolved in a solvent and added.

[0074] In a preferred embodiment of the process according to the invention, the polyether glycol is first charged and dried under vacuum at elevated temperature, optionally in the presence of a solvent, to suppress potential side reactions of Si-H to Si-OH in the presence of water. This can be carried out, for example, by vacuum distillation. The dehydrogenative coupling can be promoted by establishing a weakly acidic medium. In order to convert the alcohol to a weak acid, diammonium phosphate (DAP; 100-500 ppm) can be added before, during or after the distillation.

[0075] In a preferred embodiment of the process according to the invention, the preferably dry polyetherdiol (reactant (b)) is heated to the reaction temperature, the catalyst is added and mixed. The linear α,ω-(SiH)-functional polydialkylsiloxane (reactant (a)) is then added with controlled release of hydrogen.

[0076] In a preferred embodiment of the process according to the invention, the preferably dry polyether diol (reactant (b)) is heated to the reaction temperature, the catalyst is added and mixed. The siloxane (reactant (a)) diluted with a solvent is added and hydrogen is released in a controlled manner.

[0077] In a preferred embodiment of the process according to the invention, the preferably dry polyether diol (reactant (b)) is heated to the reaction temperature, diluted with a solvent, the catalyst is added and mixed. The siloxane (reactant (a)) is added with controlled release of hydrogen.

[0078] In a preferred embodiment of the process according to the invention, the preferably dry polyether diol (reactant (b)) is heated to the reaction temperature, diluted with a solvent, the catalyst is added and mixed. The siloxane (reactant (a)) diluted with a solvent is added and the hydrogen is released in a controlled manner.

[0079] For the four above-mentioned preferred embodiments, the following applies: The addition is preferably carried out continuously, thereby allowing a controlled reaction progress, as shown by a corresponding continuous gas release. Once the gas release is complete, the reaction is complete, as can be demonstrated by external SiH value determination.

[0080] In another preferred embodiment, the addition of pure or solvent-diluted siloxane (reactant (a)) in the above four embodiments can also be performed at intervals rather than continuously. Therefore, siloxane (reactant (a)) is added at intervals. This means that there is a pause after each addition interval, which advantageously continues until the lack of hydrogen release indicates quantitative SiH conversion of the previously added portion. The next interval amount is then added. It is preferred when the addition amount and the time of each interval remain constant, but those skilled in the art can make adjustments in specific applications. Therefore, initially a larger amount of siloxane can be added per interval at the beginning of the synthesis, and a smaller amount of siloxane can be added near the end, and vice versa.

[0081] It is always beneficial to ensure effective mixing during addition.

[0082] According to the present invention, the reaction of reactants (a) and (b) is carried out under controlled release of hydrogen until the SiH conversion is quantitative. In the context of the present invention, this should be understood to mean that the difference between the actual conversion and the target conversion is as low as possible, preferably in the range of 0% to 10%, preferably 0% to 7.5%, more preferably 0% to 5%. The term target conversion should be understood to refer to the amount of releasable hydrogen after the quantitative SiH conversion of the amount of hydrogen siloxane present in the reaction system at a specific time. The term actual conversion should be understood to refer to the amount of hydrogen actually released at a specific time. This controlled release of hydrogen can be achieved by controlled addition of component (a) to component (b). For example, if the difference between the target conversion and the actual conversion is too high, the addition rate of component (a) can be limited. The preferred method for controlling the release of hydrogen is described in detail in the embodiments.

[0083] The SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymers with repeating (AB) units produced by the process according to the invention can be used particularly advantageously as surface-active additives, in particular as cell openers, for the production of polyurethanes, preferably polyurethane foams, in particular for the production of rigid polyurethane foams; particularly preferably one-component canned PU foams (construction foams, assembly foams, one-component foams / OCF) and / or other rigid polyurethane foams in which a high open cell content is advantageous (e.g. open-cell spray foams, packaging foams, roof lining foams, pipe insulation foams, pattern foams and / or thermoformable rigid foams, etc.). These uses likewise form part of the subject matter of the present invention.

[0084] For the above-mentioned preferred applications, it is particularly desirable that the finished PU foam, preferably a rigid PU foam, shows small changes in geometric dimensions during and especially after the curing process. As a result of the high open cell content foam, this desired dimensional stability, i.e. low shrinkage, despite the post-expansion, can preferably be achieved. At the same time, it is desirable that due to this open cell content the PU foam will not have any major foam defects in the form of cavities: the foam cells should preferably still be fine and without any coarsening.

[0085] Therefore, it may be advantageous to use polyol-isocyanate prepolymers in the production of such PU foams. In particular, however, it is advantageous to add not only the foam stabilizers usually present (usually polyether siloxanes) but also cell openers, for which the use of the SiOC-bonded linear polydialkylsiloxane-polyether block copolymers according to the invention has been found to be very particularly effective.

[0086] The SiOC-bonded linear polydialkylsiloxane-polyether block copolymers having repeating (AB) units obtainable by the process according to the invention can therefore be used particularly advantageously as cell openers in the production of polyurethane foams, in particular rigid polyurethane foams.

[0087] The term "cell opener" is known per se to the person skilled in the art in the production of PU foams. Cell openers are understood to mean substances which are able or have the function of causing an increase in the open cell content during the production of polyurethane foams, preferably rigid polyurethane foams, whereas polyurethane foams generally have closed cells in most cases (i.e. in the case of rigid PU foams, generally have less than 30%, preferably less than 20%, more preferably less than 10% open cells, based on the total number of cells). The inventive use of the SiOC-bonded linear polydialkylsiloxane-polyether block copolymers with repeating (AB) units obtainable by the process according to the invention as cell openers enables a high open cell content of the resulting PU foams, especially rigid PU foams. The term "high open cell content" is further defined below.

[0088] In the polyurethane foam to be produced, preferably rigid polyurethane foam, the SiOC-bonded linear polydialkylsiloxane-polyether block copolymers with repeating (AB) units according to the invention are preferably used as surface-active additives, in particular as cell openers, in a concentration of 0.01 to 10% by weight, preferably 0.05 to 7% by weight, more preferably 0.1 to 5% by weight, in each case based on the total formulation of the polyurethane foam.

[0089] The term polyurethane foam itself is known to the person skilled in the art (see, for example, Adam et al., “Polyurethanes”, Ullmann's Encyclopedia of Industrial Chemistry—Section 7”, 2012, Wiley VCH-Verlag, Weinheim).

[0090] Preferred compositions according to the invention of PU foams, preferably rigid polyurethane foams, comprise the following components:

[0091] a) SiOC-bonded linear polydialkylsiloxane-polyether block copolymers according to the invention having repeating (AB) units

[0092] b) Polyol component

[0093] c) (Poly)isocyanate component

[0094] d) Catalyst

[0095] e) Optional foam stabilizer

[0096] f) Foaming agent

[0097] g) other additives which may be present, preferably fillers, liquid or solid flame retardants, dispersing aids, etc.

[0098] The SiOC-bonded linear polydialkylsiloxane-polyether block copolymers according to the invention having repeating (AB) units are used here as interface-active additives, preferably as cell openers.

[0099] The terms "polyurethane" and "polyurethane foam" are established technical terms that have been known to the person skilled in the art for a long time.

[0100] In the context of the present invention, polyurethane (PU) is understood in particular to mean products obtainable by reaction of polyisocyanate components with polyol components.

[0101] In addition to polyurethanes, further functional groups may also be formed in the reaction, for example uretdione, carbodiimide, isocyanurate, allophanate, biuret, urea and / or uretonimine. Therefore, for the purposes of the present invention, PU is to be understood as meaning not only polyurethanes, but also polyisocyanurate, polyurea and polyisocyanate reaction products containing uretdione, carbodiimide, allophanate, biuret and / or uretonimine groups.

[0102] Therefore, in the context of the present invention, polyurethane foam (PU foam) is understood to mean a foam obtained as a reaction product of a polyisocyanate component and a polyol component. In addition to the polyurethane of the same name, further functional groups may also be formed here, for example allophanates, biuret, urea, carbodiimide, uretdione, isocyanurate or uretonimine.

[0103] Rigid PU foam (rigid polyurethane foam) is an established technical term. The known and fundamental difference between flexible foams and rigid foams is that flexible foams display elastic properties and deformations are therefore reversible. In contrast, rigid foams deform permanently. More details about rigid polyurethane foams can also be found in "Kunststoffhandbuch, Band 7, Polyurethane [Plastics Handbook, volume 7, Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, Chapter 6. The terms "foam" and "foam material" are treated synonymously in the context of the present invention. This then also applies correspondingly to compound terms based thereon, such as rigid foam or rigid foam material etc.

[0104] Particularly preferred PU foams in the context of the present invention are rigid polyurethane foams, such as, in particular, one-component pot foams, open-cell spray foams, packaging foams, roof lining foams, pipe insulation foams, floral foams, thermoformable rigid foams and / or other rigid polyurethane foams, in which a high open-cell content is particularly advantageous.

[0105] The polyol component (b) used may be one or more organic compounds having OH groups, SH groups, NH groups and / or NH2 groups with a functionality of 1.8 to 8. The polyol component comprises at least one compound having at least two isocyanate-reactive groups selected from OH groups, SH groups, NH groups and / or NH2 groups, especially OH groups.

[0106] For example, a functionality of 1.8 can result from mixing at least one compound having a relatively high functionality, for example greater than or equal to 2, with at least one compound having a functionality of, for example, 1. This can occur in particular when polyisocyanate components (c) having a functionality of greater than 2 or further crosslinkers are used as optional additives.

[0107] Suitable compounds which can generally be used when producing PU foams are known to the person skilled in the art and are described, for example, in "Kunststoffhandbuch, Band 7, Polyurethane [Plastics Handbook, volume 7, Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1. Compounds having an OH value of 10 to 1200 mg KOH / g are generally used.

[0108] Particularly preferred compounds are all polyether polyols and polyester polyols which are customarily used for producing polyurethane systems, in particular polyurethane foams.

[0109] Furthermore, polyether polycarbonate polyols, polyols based on natural oils (natural oil-based polyols, NOPs; described in WO2005 / 033167, US2006 / 0293400, WO2006 / 094227, WO2004 / 096882, US2002 / 0103091, WO2006 / 116456, EP 1678232), filled polyols, prepolymer-based polyols and / or recycled polyols may be used.

[0110] Recycled polyols are polyols obtained from the chemical recycling of polyurethanes, for example by solvolysis, such as glycolysis, hydrolysis, acidolysis or aminolysis. The use of recycled polyols constitutes a particularly preferred embodiment of the present invention.

[0111] When the polyol component comprises a polyol-isocyanate prepolymer, this is a preferred embodiment of the present invention.

[0112] The isocyanate or polyisocyanate component (c) used may generally be one or more polyisocyanates having two or more isocyanate groups. Suitable polyisocyanates for the purposes of the present invention are all organic isocyanates having two or more isocyanate groups, in particular the aliphatic, cycloaliphatic, arylaliphatic and preferably aromatic polyfunctional isocyanates known per se.

[0113] Examples which may be mentioned here are alkylene diisocyanates having 4 to 12 carbon atoms in the alkylene group, for example dodecane 1,12-diisocyanate, 2-ethyltetramethylene 1,4-diisocyanate, 2-methylpentamethylene 1,5-diisocyanate, tetramethylene 1,4-diisocyanate, pentamethylene diisocyanate (PDI) and preferably hexamethylene 1,6-diisocyanate (HMDI), cycloaliphatic diisocyanates such as cyclohexane 1,3- and 1,4-diisocyanate and the corresponding isomer mixtures, methylenedicyclohexyl 4,4'-diisocyanate. Diisocyanates (H12MDI), isophorone diisocyanate (IPDI), methylcyclohexyl 2,4- and 2,6-diisocyanate and the corresponding isomer mixtures, and preferably aromatic diisocyanates and polyisocyanates, for example toluene 2,4- and 2,6-diisocyanate (TDI) and the corresponding isomer mixtures, naphthalene diisocyanate, diethyltoluene diisocyanate, diphenylmethane 4,4'- or 2,2'- or 2,4'-diisocyanate (MDI) and polymethylene polyphenyl polyisocyanate (PMDI, "polymeric MDI"). The organic polyisocyanates can be used alone or in the form of mixtures thereof. It is likewise possible to use the corresponding "oligomers" of the diisocyanates, for example IPDI trimers based on isocyanurates, biuret or uretdione. In addition, prepolymers based in particular on the above-mentioned isocyanates can be used. Mixtures of MDI with an average functionality of 2 to 4 and of more highly condensed analogs known as polymeric MDI (also known as "crude MDI") and the various isomers of TDI in pure form or as isomer mixtures are particularly suitable. It is also possible to use isocyanates that have been modified by the introduction of carbamates, uretdiones, isocyanurates, allophanates and other groups, which are known as modified isocyanates. Examples of particularly suitable isocyanates are also described in detail, for example, in EP 1 712 578, EP 1 161 474, WO 00 / 58383, US 2007 / 0072951, EP 1 678 232 and WO 2005 / 085310, which are incorporated herein in their entirety by reference.

[0114] The preferred ratio of the polyisocyanate component and the polyol component is expressed as a formulated index, i.e. the stoichiometric ratio of isocyanate groups to isocyanate reactive groups (e.g. OH groups, NH groups) multiplied by 100, in the range of 10 to 1000, preferably 40 to 500. An index of 100 means that the molar ratio of the reactive groups is 1:1.

[0115] Suitable catalysts (d) which can be used for the production of polyurethanes, in particular PU foams, are known to the person skilled in the art from the prior art; compounds which can be used in the context of the present invention are all those which catalyze the reaction of isocyanate groups with OH, NH or other isocyanate-reactive groups and / or the reaction of isocyanate groups with one another. Conventional catalysts known from the prior art can be used here, including, for example, amines (cyclic, acyclic; monoamines, diamines, oligomers with one or more amino groups), ammonium compounds, organometallic compounds and / or metal salts, preferably those of tin, iron, bismuth, potassium and / or zinc. In particular, the catalyst used can be a mixture of two or more such compounds.

[0116] Foam stabilizers (e) and their use in the production of PU foams are known to those skilled in the art. The use of foam stabilizers is optional; preferably one or more foam stabilizers are used. Foam stabilizers that can be used are in particular surface-active compounds (surfactants). They can be used to optimize the desired cell structure and foaming process. In the context of the present invention, in particular Si-containing compounds that assist foam generation (stabilization, cell regulation, cell opening, etc.) can be used. These compounds are well known from the prior art. More preferably, at least one foam stabilizer based on polyether siloxanes (polydialkylsiloxane-polyether copolymers) can be used. Corresponding siloxane structures that can be used in the context of the present invention are described, for example, in the following patent specifications: CN 103665385, CN 103657518, CN 103055759, CN 103044687, US 2008 / 0125503, US 2015 / 0057384, EP 152087A1, EP 1211279, EP 0867464, EP 0867465, EP 0275563. In addition to surface-active Si-containing compounds, Si-free surfactants can also be used. For example, EP 2295485 A1 describes the use of lecithin, and US 3746663 describes the use of structures based on vinylpyrrolidone as foam stabilizers for the production of rigid PU foams. Further Si-free foam stabilizers are described, for example, in EP 2511328 B1, DE 1020011007479 A1, DE 3724716 C1, EP 0734404, EP 1985642, DE 2244350 and US Pat. No. 5,236,961.

[0117] Blowing agents and their use in the production of PU foams are known to those skilled in the art. The use of blowing agents is optional; preferably, blowing agents are used. The use of a blowing agent (f) or a combination of two or more blowing agents (f) depends in principle on the nature of the foaming process used, the nature of the system and the purpose of the PU foam obtained. Chemical and / or physical blowing agents can be used, as well as combinations of both. Depending on the amount of blowing agent used, foams with high or low density can be produced. For example, a foam with a density of 3 kg / m 3 Up to 900kg / m 3 , preferably 5 to 350 kg / m 3 , more preferably 8 to 200 kg / m 3 , especially 8 to 250 kg / m 3 of bubbles.

[0118] Physical blowing agents that can preferably be used are one or more suitable compounds with a suitable boiling point and mixtures thereof, for example hydrocarbons with 3, 4 or 5 carbon atoms, preferably cyclo-, iso-, n-pentane, hydrofluorocarbons (HFCs), preferably HFC245fa, HFC134a or HFC365mfc, hydrochlorofluorocarbons (HCFCs), preferably HCFC141b, hydrofluoroolefins (HFOs) or hydrohaloolefins, preferably 1234ze, 1234yf, 1224yd, 1233zd(E) or 1336mzz, esters, preferably methyl formate, ketones, preferably acetone, ethers, preferably dimethoxymethane, or chlorinated hydrocarbons, preferably dichloromethane or 1,2-dichloroethane.

[0119] Likewise preferably, it is also possible to use gaseous blowing agents in pressurized tanks, useful examples of which include all gases suitable for this purpose under pressure or in pressure liquefied form, for example hydrocarbons, such as butane isomers and propane isomers, dimethyl ether, nitrogen, air and other suitable gases.

[0120] The chemical blowing agent used may preferably be one or more compounds which react with NCO groups and release a gas, such as water or formic acid, or which release a gas during the reaction as a result of the temperature increase, for example sodium bicarbonate.

[0121] The optional additives (g) used may be one or more substances known in the prior art and used for the production of polyurethanes, in particular PU foams, such as crosslinkers, chain extenders, stabilizers against oxidative degradation (called antioxidants), flame retardants, biocides, cell densification additives, nucleating agents, other cell openers, solid fillers, antistatic additives, thickeners, dyes, pigments, color pastes, fragrances and / or emulsifiers, etc.

[0122] As optional flame retardants, the composition according to the invention may contain one or more known flame retardants suitable for the production of PU foams, for example halogen-containing or halogen-free organic phosphorus-containing compounds, for example triethyl phosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(2-chloroethyl) phosphate (TCEP), dimethyl methanephosphonate (DMMP), dimethyl propanephosphonate (DMPP), ammonium polyphosphate or red phosphorus, chlorinated paraffins, nitrogen-containing compounds such as melamine, melamine cyanurate or melamine polyphosphate, or halogenated compounds, for example chlorinated and / or brominated polyether polyols and / or polyester polyols. Mixtures of different flame retardants can also be used.

[0123] Unless a description to the contrary is apparent, any preferred or particularly preferred embodiment of the present invention may be combined with one or more other preferred or particularly preferred embodiments of the present invention.

[0124] The process for producing PU foam can be carried out by any known method, for example by manual mixing or preferably by a foaming machine. If a foaming machine is used for the process, a high-pressure or low-pressure foaming machine can be used. The process for producing PU foam can be carried out batchwise or continuously and can use, for example, a one-component, 1.5-component or two-component system as described in EP 3717538 A1, US 7776934 B2, EP1400547 B1 or EP 2780384 B2.

[0125] One-component canned PU foams are well known to the person skilled in the art from the prior art. Throughout the context of the present invention, the term "one-component canned PU foam" comprises polyurethane foams which are preferably characterized by the presence of a polyol-isocyanate prepolymer which can be foamed from a pressurized tank by means of a gas as blowing agent and thus foams.

[0126] Suitable polymers which are preferred for this purpose can be obtained, for example, by reacting polyols and (poly)isocyanates with one another with the aid of suitable catalysts (for example blowing catalysts such as 2,2'-dimorpholinyl diethyl ether), or in the absence of a catalyst. The final curing of these prepolymers then takes place under the action of moisture, for example from the environment. Fields of use of foams of this type are the assembly, bonding and sealing of windows, door frames, pipes, bushings, etc., and the filling of gaps in bricks, cavities, cracks and joints.

[0127] Spray foam is a free-rising foam that is applied to a substrate by spraying a liquid reaction component onto the substrate. The process is usually achieved by a spray foaming machine, which can be implemented as a high-pressure or low-pressure machine and combines and mixes two components (polyol mixture and (poly)isocyanate). The foam is usually discharged by a static mixer in the form of a spray gun. In principle, similar to the principle of canned foam, the raw material or foam can be discharged from a larger container by gas pressure instead. The foam is used for the purpose of isolation, as well as for structural purposes in walls, roofs, floors, and can be open-cell or closed-cell depending on the application.

[0128] Packaging foams are used for packaging, protection and cushioning of sensitive goods. Low-density open-cell foams are usually used, which are intended to tightly enclose the goods to be protected and protect them from damage, impacts, etc. For this purpose, the foam is also optionally foamed directly into the gap between the packaging and the goods.

[0129] Thermoformable rigid polyurethane foams are rigid polyurethane foams that are mechanically deformed after production, for example by applying heat, water / steam and pressure. Foams that are first in block form and optionally cut to size are used to produce shaped articles. Examples are headliner foams and hood liner foams (foams for tailgates and cladding).

[0130] Flower-like foams, such as are used for arranging flowers etc., are polyurethane foams which, due to their low density, mechanical properties and high open cell content, are suitable for accommodating flowers and other objects by inserting them into the foam.

[0131] Pipe insulation foams are polyurethane foams used for pipe insulation. They protect the pipe or the pipe contents firstly from heat or cooling losses and secondly from mechanical influences. Especially in the field of pipelines laid in water bodies, offshore and deep sea, a high open cell content is required in some cases for mechanical reasons.

[0132] SiOC-bonded linear polydialkylsiloxane-polyether block copolymers with repeating (AB) units can preferably be used as interface-active additives, in particular as some cell openers, especially in all other PU foams, in particular rigid PU foams, in which a high open cell content is desired, which has a direct positive effect on, for example, the dimensional stability of the foam.

[0133] The determination of the open cell content / closed cell content of rigid polyurethane foams is a trivial matter for the person skilled in the art and can preferably be carried out according to DIN ISO 4590:2016-12 “Rigid cellular plastics—Determination of the volume percentage of open cells and of closed cells”, for example using a gas pycnometer.

[0134] In the context of the present invention, "high open cell content" is understood to mean that the cells of the PU foam, in particular the rigid PU foam, have a content of open cells of preferably ≥30%, further preferably ≥50%, in particular ≥70%. Possible upper limits in the open cell content may be, for example, 90% of cells, or, for example, 80% of cells, or, for example, 100% of cells.

[0135] The dimensional stability of one-component canister PU foams can preferably be measured by method TM1004:2013 of FEICA-Association of the European Adhesive & Sealant Industry (“Determination of the Dimensional Stability of an OCF Canister Foam”, Brussels, 19.02.2013).

[0136] experiment:

[0137] Test method:

[0138] In the context of the present invention, it is preferred to use the methods described below to determine parameters or measured values. In particular, these methods are used in the embodiments of this intellectual property.

[0139] The SiH conversion rate of dehydrogenation coupling is determined by the release of (residual) Si-H present in the sample as elemental hydrogen catalyzed by butoxide salt and its quantitative determination. In order to determine the SiH value, a limited amount of sample to be analyzed (between 0.3 and 10g sample according to the expected SiH value) is weighed into a reaction vessel with a magnetic stirring bar on an analytical balance. The reaction vessel is equipped with a dropping funnel containing about 25ml sodium butoxide solution (5% in n-butanol). The reaction vessel is connected to a 50ml water-filled burette via a frosted glass joint with a three-way tap, and the water-filled burette is provided with a water-filled balance container via a hose. The reaction vessel is erected on a magnetic stirring plate at about eye level. The three-way tap should be set at the beginning of the analysis so that all three paths are open. The balance container is taken out of its holder and moved toward the burette. The purpose is to make the two liquid levels (burette & balance container) zero straight line. Once this is the case, the three-way tap is set so that only the path between the burette and the reaction vessel is open. After a waiting time of 60 seconds, in order to check the integrity of the apparatus, the liquid level is made straight at zero again. In the event of a leak, the ground glass joint should be checked and re-oiled, if necessary, in order to create a leak-free apparatus. If a leak has been found and remedied, a zero level balancing should be carried out again. If the test apparatus is leak-free, the magnetic stirrer is set at a low stirring speed and the butoxide solution is added dropwise so that the falling column in the burette is not broken. Time and again, the liquid level becomes straight again. As soon as the volume of liquid discharged remains stable, that is, the volume does not change, the liquid level becomes straight and the volume obtained is recorded as the maximum gas volume released. Taking into account the maximum gas volume released according to The SiH value can be calculated from the weighed amount using the universal gas equation.

[0140] In the context of the present invention, the weight-average and number-average molecular weights of the prepared SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymers and for linear α,ω-(SiH)-functional polyalkylsiloxanes were determined by gel permeation chromatography (GPC) and calibration against polystyrene standards. In the following examples, the polydispersity index (PDI) is reported as a further characteristic parameter for describing the molecular weight distribution. At a temperature of 30° C. and a flow rate of 1 mL / min (mobile phase: THF), a SDV equipped with an RI detector and consisting of a 0.8×5 cm front column and two 0.8×30 cm main columns was used. GPC analysis was performed using a PSS SECurity 1260 (Agilent 1260) column combination. The sample concentration was 10 g / l and the injection volume was 20 μl.

[0141] Wet chemical analyses were performed according to international standard methods: iodine value (IV; DGF CV 11a (53); acid value (AV; DGF CV 2); OH value (OHV; ASTM D 4274C). DETAILED DESCRIPTION

[0142] A feature of the process according to the invention is that the two reactants (a) and (b) are preferably reacted in equimolar amounts with a controlled release of hydrogen until the SiH conversion is quantitative, in particular by metering reactant (a) into the initial charge of reactant (b). The term "controlled release of hydrogen" particularly envisages that the addition rate of components (a) to (b) is such that the difference between the actual conversion and the target conversion is preferably in the range of 0% to 10%, preferably 0% to 7.5%, more preferably 0% to 5%.

[0143] The preferred method of controlling the release of hydrogen is as follows:

[0144] In the equipped with stainless steel Sigma The reaction was carried out in a 1000 ml ground glass four-necked flask with an internal thermometer and a reflux cooler with a gas discharge hose. The heating medium was a standard heating mantle controlled with PID fuzzy logic to establish the target temperature. The siloxane to be added (=component (a)) was sucked in via a storage container placed on a tared balance using a peristaltic pump and transferred to the ground glass flask.

[0145] The gas discharge hose of the ground glass flask enters via a transition piece with an olive into a hermetically sealed 4-liter two-necked flask filled with boiling gas-free water with zero dead volume. The two-necked flask is also provided with a gas inlet tube with an olive extending to just above the bottom of the column. The two-necked flask is placed on a tared balance.

[0146] Immediately starting the siloxane addition caused the reaction to set in and the resulting gas, which produced a volume expansion throughout the system, was transferred to the two-necked flask. This in turn caused the water content to be discharged from the flask via the inlet tube and collected in another collection container.

[0147] Continuous data capture of individual substances via the differential weight of the siloxane and the two-necked flask allows identification of the reaction rate of the two reactants (a) and (b) to provide the product. This is done by plotting the data pair of the mass of the siloxane storage flask and the mass of the two-necked flask. The mass of the added siloxane can be used to calculate the theoretical gas volume that will be occupied by the hydrogen (byproduct) released by the condensation reaction at this time. Therefore, the target conversion rate of the corresponding reaction system can be calculated over the entire process of the reaction. This is in Figures 1 to 5 Shown as a dotted line.

[0148] Using the mass of water released at a specific temperature with the aid of the density of water, the actual volume of gas released can be determined. The gas volume is calculated using the gas law for ideal gases converted to standard conditions. Thus, the actual conversion of the corresponding reaction system can be determined over the entire course of the reaction. This is done in Figures 1 to 5 Shown as a solid line.

[0149] The quotient of the actual gas volume released and the theoretical gas volume describes the degree of conversion of the reaction at this time.

[0150] As can be seen from the following invention embodiments and Figure 6 As can be clearly seen, it is very particularly preferred according to the invention when the siloxane addition rate is selected such that the difference between the "actual conversion" and the "target conversion" is preferably in the range of 0% to 10%, preferably 0% to 7.5%, more preferably 0% to 5%. This provision applies when the siloxane addition amount is above 10% of the total amount to be added and more preferably above 5% of the total amount to be added. In this way, the person skilled in the art will be able to quickly establish the optimal siloxane addition rate by simple manual experiments, thereby achieving an optimal controlled hydrogen release.

[0151] Example 1 (according to the present invention):

[0152] First, 115.8g of dried polyoxyalkylene glycol with a water content of <0.02% was charged into a 1000ml ground glass four-necked flask equipped with a stainless steel Sigma stirrer, an addition unit with a peristaltic pump, an internal thermometer, and a reflux cooler with a gas discharge hose. The weight-average molar mass of the polyoxyalkylene glycol was 2800g / mol and the ethylene oxide / propylene oxide ratio was about 1:1. The linear alkylbenzene with a boiling range of about 240°C to 314°C was combined with 198.0g. The mixture was heated to a temperature of 105°C. Then 123.0mg of tris(pentafluorophenyl)borane (600ppm, based on the total amount of reactants) dissolved in 20g of the above-mentioned alkylbenzene was added. After a stirring time of 5 minutes, 180.0g of α,ω-hydrogensiloxane (average chain length N=30) and a 1:1 mixture of the above-mentioned alkylbenzene were added in an equimolar ratio with the polyoxyalkylene glycol used. The amount added and the rate of addition were adjusted using a programmable peristaltic pump so that the total amount of hydrogen siloxane was divided into about 18 individual intervals of 10 g each. The actual addition period of 2 minutes was immediately followed by a pause for 10 minutes. The process was repeated in the same manner for all 18 intervals. After the addition of the stoichiometric amount of siloxane, a significant viscosity increase was observed. The end of the reaction was clearly discernible from the weakened gas evolution. The gas volume SiH determination showed complete conversion. A viscosity of 41950 mPa s, M w A colorless, high viscosity product with a weight average molecular weight of 171400 g / mol and a PDI of 3.214.

[0153] Example 2 (according to the present invention):

[0154] First, 210.9g of dried polyoxyalkylene glycol was loaded into a 1000ml ground glass four-necked flask equipped with a stainless steel Sigma stirrer, an addition unit with a peristaltic pump, an internal thermometer and a reflux cooler with a gas discharge hose, and its water content was <0.02%. The weight-average molar mass was 2800g / mol and the ethylene oxide / propylene oxide ratio was about 1:1. The polyoxyalkylene glycol was combined with 536.4g of a linear alkylbenzene with a boiling range of about 240°C to 314°C. The mixture was heated to a temperature of 105°C. Then 260.0mg of tris(pentafluorophenyl)borane (700ppm, based on the total amount of reactants) dissolved in 20g of the above-mentioned alkylbenzene was added. After 5 minutes of stirring time, 160.0g of α, ω-hydrogensiloxane (average chain length N=30) was added in an equimolar ratio with the polyoxyalkylene glycol used. A programmable peristaltic pump was used to adjust the addition amount and rate so that the entire amount of hydrogen siloxane was added continuously within 120 minutes. After the addition of the stoichiometric amount of siloxane, a significant viscosity increase was observed. The end of the reaction was clearly discernible from the weakened gas evolution. The gas volume SiH determination showed complete conversion. A viscosity of 8786 mPa s, M w A colorless, high viscosity product with a weight average molecular weight of 101800 g / mol and a PDI of 2.465.

[0155] Example 3 (according to the present invention):

[0156] First, 135.4g of dried polyoxyalkylene glycol with a water content of <0.02% was loaded into a 1000ml ground glass four-necked flask equipped with a stainless steel Sigma stirrer, an addition unit with a peristaltic pump, an internal thermometer, and a reflux cooler with a gas discharge hose. The weight-average molar mass of the polyoxyalkylene glycol was 2800g / mol and the ethylene oxide / propylene oxide ratio was about 1:1. The linear alkylbenzene with a boiling range of about 240°C to 314°C was combined with 234.4g. The mixture was heated to a temperature of 105°C. Then 167.0mg of tris(pentafluorophenyl)borane (700ppm, based on the total amount of reactants) dissolved in 20g of the above-mentioned alkylbenzene was added. After a stirring time of 5 minutes, a 1:1 mixture of 205.4g of α,ω-hydrogensiloxane (average chain length N=30) and the above-mentioned alkylbenzene was added in an equimolar ratio with the polyoxyalkylene glycol used. The amount added and the rate of addition were adjusted using a programmable peristaltic pump so that the total amount of hydrogen siloxane was divided into about 18 individual interval amounts of 11.4 g each. The actual addition period of 2 minutes was immediately followed by a pause for 15 minutes. The process was repeated in the same manner for all 18 interval amounts. After the addition of the stoichiometric amount of siloxane, a significant viscosity increase was observed. The end of the reaction was clearly discernible from the weakened gas evolution. The gas volume SiH determination showed complete conversion. A viscosity of 6197 mPa s, M w A colorless, high-viscosity product with a weight average molecular weight of 91212 g / mol and a PDI of 2.341 was obtained.

[0157] Example 4 (according to the present invention):

[0158] First, 160.9g of dried polyoxyalkylene glycol was loaded into a 1000ml ground glass four-necked flask equipped with a stainless steel Sigma stirrer, an addition unit with a peristaltic pump, an internal thermometer, and a reflux cooler with a gas discharge hose, and its water content was <0.02%. The weight-average molar mass was 2800g / mol and the ethylene oxide / propylene oxide ratio was about 1:1. The polyoxyalkylene glycol was combined with 410.6g of linear alkylbenzene with a boiling range of about 240°C to 314°C. The mixture was heated to a temperature of 105°C. Then 201.0mg of tris(pentafluorophenyl)borane (700ppm, based on the total amount of reactants) dissolved in 20g of the above-mentioned alkylbenzene was added. After 5 minutes of stirring time, 160.0g of α, ω-hydrogen siloxane (average chain length N=30) was added in an equimolar ratio with the polyoxyalkylene glycol used. A programmable peristaltic pump was used to adjust the addition amount and rate so that the entire amount of hydrogen siloxane was added continuously within 221 minutes. After the addition of the stoichiometric amount of siloxane, a significant viscosity increase was observed. The end of the reaction was clearly discernible from the weakened gas evolution. The gas volume SiH determination showed complete conversion. A viscosity of 60210 mPa s, M wA colorless, high-viscosity product with a weight average molecular weight of 173,600 g / mol and a PDI of 3.095 was obtained.

[0159] Example 5 (not according to the invention):

[0160] First, 115.8g of dried polyoxyalkylene glycol with a water content of <0.02% was loaded into a 1000ml ground glass four-necked flask equipped with a stainless steel Sigma stirrer, an addition unit with a peristaltic pump, an internal thermometer, and a reflux cooler with a gas discharge hose. The weight-average molar mass was 2800g / mol and the ethylene oxide / propylene oxide ratio was about 1:1. The polyoxyalkylene glycol was combined with 198.0g of a linear alkylbenzene with a boiling range of about 240°C to 314°C. The mixture was heated to a temperature of 105°C. Then 123.0mg of tris(pentafluorophenyl)borane (600ppm, based on the total amount of reactants) dissolved in 20g of the above-mentioned alkylbenzene was added. After 5 minutes of stirring time, 180g of α,ω-hydrogensiloxane (average chain length N=30) and a 1:1 mixture of the above-mentioned alkylbenzene were added in an equimolar ratio with the polyoxyalkylene glycol used. A programmable peristaltic pump was used to adjust the addition amount and rate so that the entire amount of hydrogen siloxane was added continuously within 17 minutes. After the addition of the stoichiometric amount of siloxane, a significant viscosity increase was observed. The end of the reaction was clearly discernible from the weakened gas evolution. The gas volume SiH determination showed complete conversion. A viscosity of 13780 mPa*s, M w A colorless, high viscosity product with a weight average molecular weight of 145100 g / mol and a PDI of 2.689.

[0161] Attached photos Figures 1 to 6 :

[0162] Attached photos Figures 1 to 6 Embodiments 1 to 5 of the present invention are shown. Figures 1 to 5 Each shows the volume of hydrogen released as a function of the amount of hydrogen siloxane added for Examples 1 to 5. The experiments differed in the manner of addition (continuous or intermittent) and / or the rate of addition as described above. The dashed line in each case represents the target conversion. The solid line in each case represents the actual conversion.

[0163] Figure 6 A summary of the effect of reaction management on the difference between target conversion and actual conversion as a function of the mass of siloxane added for Examples 1 to 5 is shown.

[0164] Example of using SiOC-bonded linear polydialkylsiloxane-polyether block copolymers as cell openers in polyurethane formulations:

[0165] As a cell opener, the SiOC-bonded linear polydialkylsiloxane-polyether block copolymer obtained in the above-mentioned Inventive Examples (Examples 1 to 4) and Non-Inventive Example (Example 5) was used.

[0166] Rigid polyurethane foam is produced using the following raw materials:

[0167] G1000: Polyether polyol from Rokita

[0168] D1002: Polyether polyol from Rokita

[0169] DE10WF15: Polyether polyol from Covestro

[0170] CP3322: Polyether polyol from Dow

[0171] PEG600: Polyethylene glycol

[0172] Stabilizer: from Evonik Operations GmbH Stabilizers,

[0173] B 84728 (single component canned PU foam)

[0174] B 8870(Packaging foam)

[0175] TCPP: Tris(2-chloroisopropyl) phosphate (flame retardant) from Fyrol

[0176] DMDEE: Amine-based catalysts from Evonik Operations GmbH

[0177] dimethyl ether

[0178] Propane

[0179] n-Butane

[0180] Isobutane

[0181] MDI: From Covestro 44V20L, diphenylmethane 4,4'-diisocyanate (MDI) with isomeric and higher functionality homologues

[0182] Production of polyurethane foam:

[0183] For testing in one-component canned PU foams, all components of the formulation (see Table 1) except the blowing agent were introduced into an empty aerosol can. Subsequently, the can was sealed with its corresponding valve and, finally, the specified amount of blowing agent (LPG, DME) was metered in via a pressurized gas titrator. The can was then shaken manually for 1 minute and then rotated in a rotary mixer for 30 minutes to obtain a homogeneous mixture and to enable the formation of a homogeneous prepolymer.

[0184] For the test of pore structure or internal defects, the contents of the can are discharged after 24 h through a conventional foam gun. This involves discharging a stream of foam onto paper and assessing the foam quality of the visually cured foam after 24 h on a scale from 1 to 10. For this purpose, the foam is cut in the middle. The value 10 here represents perfect foam without internal defects or very fine cells; in contrast, the number 1 represents collapsed foam or very coarse cells.

[0185] In order to determine the dimensional stability of the one-component canned PU foam in terms of the shrinkage tendency of the expansion characteristics, the dimensional stability test (DMS test) according to the method TM 1004:2013 of the FEICA-Association of the European Adhesive & Sealant Industry ("Determination of the Dimensional Stability of an OCF Canister Foam", Brussels, 19.02.2013) was adopted. For this purpose, two wooden panels were immersed in water for 30 seconds to allow the substrate to absorb a defined amount of water. Before applying the foam, the foam can was manually shaken for 1 minute and the initial part of the contents of the can was first discarded (activating the spray gun for about 3-5 seconds). Subsequently, 15g of foam was applied between the wooden panels. The wooden panels were fixed with spacers and wooden clamps so that they had a constant distance of 2 cm from each other. After 24h, the spacers and wooden clamps were removed and the width between the two wooden panels was determined using a slide rule. The measurement of the width is repeated after 2, 3, 7 and 14 days and the percentage change compared to 2 cm as the starting point is determined and recorded. In this case, minimal shrinkage or post-expansion is expected, which is associated with the high open cell content of the foam.

[0186] In the case of packaged foam formulations, the test was carried out by the manual mixing method. For this purpose, all components according to the formulation in Table 2 except the polyisocyanate (MDI) were weighed in a beaker and mixed for 30 s at 1000 rpm by means of a disk stirrer (diameter 6 cm). The polyisocyanate (MDI) was subsequently added and the reaction mixture was stirred with the stirrer at 3000 rpm for 5 s and then applied to a 27x27 cm floor area. 2 The foam moldings were demoulded after 10 minutes. After 24 h, the shrinkage properties of the foam moldings were visually evaluated. Also after 24 h, cut surfaces in the foam were used to visually evaluate the degree of internal defects and the cell structure on a scale of 1 to 10, where 10 represents a flawless foam and 1 represents a foam with very significant defects.

[0187] Table 1 (Formula of one-component canned PU foam)

[0188]

[0189]

[0190] Table 2 (Formula of two-component canned PU foam)

[0191]

[0192] The results of the foaming tests in the one-component canned PU foams of the examples are summarized in Table 3. Foam bundles were prepared and subjected to DMS testing as described above. Internal defects or cell fineness were graded on a scale of 1-10. Dimensional stability (DMS) was reported as shrinkage % (negative values) or expansion % (positive values) based on the original thickness of the foam. Measurements were made after 1, 2, 3, 7 and 14 days.

[0193] Table 3: Foaming test results in one-component canned PU foam

[0194]

[0195] It is evident from the experiments that the cell openers according to the invention (Examples 1-4) achieve a significantly improved dimensional stability compared to the non-inventive product from Example 5. No adverse effects on the cell structure and internal defects were observed here.

[0196] The results of the foaming tests in the packaging foams of the examples are summarized in Table 4. Similar to the tests in the one-component potted PU foams, the internal defects and cell structure were rated on a scale of 1-10.

[0197] Table 4: Results of the foaming test in two-component packaging foam

[0198]

[0199] It is obvious from the experiment that the cell opener according to the present invention effectively prevents cell shrinkage without showing any adverse effect on the cell structure and internal defects (Example 11). In non-inventive Example 12, slight shrinkage of the foam molding after 24 hours is obvious, which is caused by insufficient cell opening. At the same time, compared with Example 11, the cell structure and internal defects are deteriorated.

Claims

1. A process for preparing SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymers comprising repeating (AB) units, comprising reacting a linear α,ω-(SiH)-functional polydialkylsiloxane (a) with a linear α,ω-(OH)-functional polyoxyalkylene (b) using one or more compounds of elements of main group III and / or of the third transition group as catalyst (c), optionally in the presence of a solvent (d), characterized in that The two reactants (a) and (b) are preferably reacted in equimolar amounts with controlled hydrogen release until the SiH conversion is quantitative.

2. The method according to claim 1, characterized in that The linear α,ω-(SiH)-functional polydialkylsiloxanes have an SiH value of 0.25 to 3.0 mol / kg, preferably 0.5 to 2.0 mol / kg, in particular 0.75 to 1.5 mol / kg.

3. The method according to claim 1 or 2, characterized in that The linear α,ω-(SiH)-functional polydialkylsiloxane conforms to the general formula (I): M'-D a -M'Formula (I) in M’=[HR 1 2SiO 1 / 2 ] D=[R 1 2SiO 2 / 2 ] a=8-100, preferably 10-60, particularly preferably 20-50, R 1 = is independently at each occurrence the same or different hydrocarbon radicals having 1 to 20 carbon atoms, preferably methyl, ethyl, propyl or butyl, particularly preferably methyl.

4. The method according to any one of claims 1 to 3, characterized in that The linear α,ω-(OH)-functional polyoxyalkylene conforms to formula (II): HO-(C n H( 2n-m )R 2 m O-) b -H formula (II) b=1-200, preferably 10-100, particularly preferably 25-60, n＝2-4， m = 0 or 1, R 2 = is independently at each occurrence identical or different hydrocarbon radicals having 1 to 12 carbon atoms, preferably methyl, ethyl, propyl or butyl, particularly preferably methyl or ethyl.

5. The method according to any one of claims 1 to 4, characterized in that The oxyalkylene units in the linear α,ω-(OH)-functional polyoxyalkylenes consist essentially of oxyethylene and / or oxypropylene units, preferably of mixed oxyethylene and oxypropylene units, in particular with an oxyethylene proportion of 25 to 70% by weight and a oxypropylene proportion of 70 to 25% by weight, based on the total content of oxyalkylene units.

6. The method according to any one of claims 1 to 5, characterized in that The molar ratio of the two reactants (a) to (b) is in the range of 0.9 to 1.10, preferably 0.98 to 1.02, in particular 1 to 1.

7. The method according to any one of claims 1 to 6, characterized in that This is carried out in the presence of a solvent, wherein the reactants (a) and / or (b) are mixed with a solvent, wherein the total solvent proportion, based on the total amount of reactants (a) and (b) and solvent, is preferably 40% to 75% by weight of solvent, in particular 55% to 65% by weight of solvent.

8. The method according to any one of claims 1 to 7, characterized in that The reaction of reactants (a) and (b) is carried out such that reactant (b) is initially charged and reactant (a) is added, wherein the addition is carried out continuously or at intervals, in particular as follows: (i) heating reactant (b) to reaction temperature, adding a catalyst and mixing, then adding reactant (a) and controlled release of hydrogen, (ii) heating the reactant (b) to the reaction temperature, adding a catalyst and mixing, then adding the reactant (a) diluted with a solvent, and controlled release of hydrogen, (iii) heating reactant (b) to reaction temperature, diluting with solvent, adding catalyst and mixing, then adding reactant (a) and controlled release of hydrogen, or (iv) The reactant (b) is heated to the reaction temperature, diluted with a solvent, a catalyst is added and mixed, and then the reactant (a) diluted with a solvent is added with controlled release of hydrogen.

9. The method according to any one of claims 1 to 8, characterized in that The reaction temperature for preparing the SiOC-bonded linear polydialkylsiloxane-polyoxyalkylene block copolymer having repeating (AB) units is 60 to 140°C, in particular 100 to 120°C.

10. The method according to any one of claims 1 to 9, characterized in that The catalyst is used in an amount of 0.01-0.2 wt. %, preferably 0.03-0.10 wt. %, based on the total amount of reactants (a) and (b), wherein the compound of the element of the main group III used is preferably a boron-containing and / or aluminum-containing catalyst, and / or the compound of the element of the third transition group used is preferably a scandium-containing, yttrium-containing, lanthanum-containing and / or lanthanide-containing catalyst.

11. The method according to any one of claims 1 to 10, characterized in that The release of hydrogen is controlled by adjusting the addition rate of component (a) relative to (b) so that the difference between the actual conversion and the target conversion is 0% to 10%, preferably 0% to 7.5%, more preferably 0% to 5%.

12. SiOC-bonded linear polydimethylsiloxane-polyether block copolymer comprising repeating (AB) units, prepared by the process of any one of claims 1 to 11.

13. The block copolymer according to claim 12, characterized in that The content of the total siloxane blocks (A) is 20-60% by weight, in particular 40-50% by weight, and the proportion of the polyoxyalkylene blocks (B) is 80-40% by weight, preferably 60-50% by weight, based on the total block copolymers, wherein the average weight average molecular weight M of the block copolymers is w Preferably, it is at least 10,000 g / mol to 250,000 g / mol, preferably 15,000 g / mol to 225,000 g / mol, in particular 20,000 g / mol to 200,000 g / mol, the weight average molecular weight being able to be determined by GPC.

14. Use of the SiOC-bonded linear polydialkylsiloxane-polyether block copolymers comprising repeating (AB) units according to claim 12 or 13 as interface-active additives, in particular as cell openers, for producing polyurethane foams, preferably for producing rigid polyurethane foams, in particular for producing rigid polyurethane foams with a high open cell content.

15. Polyurethane foam, preferably rigid polyurethane foam, in particular rigid polyurethane foam with a high open cell content, produced using SiOC-bonded linear polydialkylsiloxane-polyether block copolymers comprising repeating (AB) units according to claim 12 or 13.

16. Use of the polyurethane foam, preferably rigid polyurethane foam, according to claim 15 for producing foam moldings, spray foams, insulating foams, sealing compounds, adhesive compounds, insulation compounds, assembly compounds and / or filling compounds.

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