SHAPED FLEXIBLE PU FOAM ARTICLES

Abstract

A shaped flexible hot-cure PU foam article, preferably mattress and/or cushion, may be obtained by reaction of at least one polyol component and at least one isocyanate component in the presence of at least one blowing agent and one or more catalysts that catalyze the isocyanate-polyol and/or isocyanate-water reactions and/or isocyanate trimerization, foam stabilizer, and further additives. The foam stabilizer may include at least one compound of formula (1)

[R.sup.1.sub.2R.sup.2SiO.sub.1/2].sub.a[R.sup.1.sub.3SiO.sub.1/2].sub.b[R.sup.1.sub.2SiO.sub.2/2].sub.c[R.sup.1R.sup.2SiO.sub.2/2].sub.d[R.sup.3SiO.sub.3/2].sub.e[SiO.sub.4/2].sub.fG.sub.g(1).

Claims

1. A shaped flexible hot-cure PU foam article, obtained by a process comprising reacting a mixture comprising a polyol component and a isocyanate component in the presence of a component comprising a blowing agent, a catalyst suitable to catalyze an isocyanate-polyol and/or isocyanate-water reactions and/or isocyanate trimerization, a foam stabilizer, and optionally, a further additive, wherein the foam stabilizer comprises a compound of formula (1):
[R.sup.1.sub.2R.sup.2SiO.sub.1/2].sub.a[R.sup.1.sub.3SiO.sub.1/2].sub.b[R.sup.1.sub.2SiO.sub.2/2].sub.c[R.sup.1R.sup.2SiO.sub.2/2].sub.d[R.sup.3SiO.sub.3/2].sub.e[SiO.sub.4/2].sub.fG.sub.g(1), wherein a is in a range of from 0 to 12, b is in a range of from 0 to 8, c is in a range of from 15 to 300, d is in a range of from 0 to 40, e is in a range of from 0 to 10, f is in a range of from 0 to 5, g is in a range of from greater than 0 to 3, a+b+c+d+e+f+g>23, a+b?2, a+d?1 wherein G is independently a bridging group of formula (2) ##STR00003## wherein R.sup.x is independently a linear organic, branched organic, an Si containing radical, m is independently 1 or 2, n is independently 1 or 2, n+m=3, y1, y2, and y3 are independently 0 or 1, y1+y2+y3>0 to 3, wherein R.sup.1 is independently a C1 to C16 alkyl radical, C6 to C16 aryl radical, H, R.sup.2 is independently a polyether of formula (3), obtained by polymerizing at least one alkylene oxide, or an organic radical of formula (4)
R.sup.4O[C.sub.2H.sub.4O].sub.i[C.sub.3H.sub.6O].sub.j[CR.sup.6.sub.2CR.sup.6.sub.2O].sub.kR.sup.7(3),
O.sub.hR.sup.8(4), wherein h is 0 or 1, i is in a range of from 0 to 150, j is in a range of from 0 to 150, k is in a range of from 0 to 80, p in a range of from 1 to 18, i+j+k?3, R.sup.3 is independently an alkyl radical or aryl radicals, either or which is optionally substituted with one or more hetero atoms, R.sup.4 is a divalent organic radical, R.sup.5 is independently a C1 to C16 alkyl radical or C6 to C16 aryl radical, R.sup.6 is independently a C1 to C16 alkyl radical, optionally comprising an ether or halogen substitution, a C6 to C18 aryl radical, optionally comprising an ether, or H, R.sup.7 is independently H, alkyl, C(O)R.sup.9, C(O)OR.sup.9 or C(O)NHR.sup.9, optionally comprising a hetero atom substitution, R.sup.8 is independently an alkyl radical or aryl radical, optionally comprising an OH, ether, epoxide, ester, amine or/and halogen, R.sup.9 is independently a C1 to C16 alkyl radical or C6 to C16 aryl radical.

2. The article of claim 1, which is a standard flexible PU foam, a viscoelastic PU foam, or a hypersoft PU foam.

3. The article of claim 1, in the form of a shaped article having a height in a range of from 1 cm to 50 cm and a width in a range of from 20 cm to 300 cm.

4. The article of claim 1, which, based on its starting volume, is compressed by at least 20?% and kept in compressed form by an auxiliary.

5. The article of claim 1, which is in a compressed state.

6. The article of claim 1, comprising the compound of formula (1) in a total in a range of from 0.05 to 3.0 wt. %, based on an entire flexible hot-cure PU foam weight.

7. The article of claim 1, obtained using one or more recycled polyols.

8. The article of claim 1, wherein the compound of formula (1) comprises at least 1 wt. % of high molecular weight product proportion with a molecular weight of ?100 000 g/mol, determined by gel permeation chromatography.

9. The article of claim 1, wherein the compound of formula (1) is made by catalyzed addition reaction of a siloxane comprising a silane hydrogen atom with a linear polyoxyalkylene oxide polyether, wherein a linear chain of the linear polyoxyalkylene oxide polyether is blocked at one end by an alkyleneoxy group and bears a hydrogen atom or has been capped.

10. The article linear polyoxyalkylene oxide polyether, wherein G comprises a (O1/2).sub.nSiR.sup.1.sub.m-groups that is connected by an organic or Si-comprising radical, and when a difunctional crosslinker is used, G is independently (i), (ii), or (iii)
(O.sub.1/2).sub.nSiR.sup.1.sub.mCH.sub.2CHR.sup.10R.sup.11CHR.sup.10CH.sub.2SiR.sup.1.sub.m(O.sub.1/2).sub.n(i)
(O.sub.1/2).sub.nSiR.sup.1.sub.mCH.sub.2CHR.sup.10R.sup.11CR.sup.10?CH.sub.2(ii)
(O.sub.1/2).sub.nSiR.sup.1.sub.mCH.sub.2CHR.sup.10R.sup.11CR.sup.10?CR.sup.10CH.sub.3(iii) with the proviso that the radical (i) is present, wherein R.sup.10 is independently a C1 to C16 alkyl radical, C6 to C16 aryl radical or H, R.sup.11 is independently a divalent organic radicals, optionally comprising an ether, ester, or amide interruption and optionally comprising an OH or (SiR.sup.1.sub.2O).sub.xSiR.sup.1.sub.2, x is in a range of from 1 to 50.

11. A process of improving dimensional recovery of a shaped flexible hot-cure PU foam article after compression over a period of at least 20 hours, the method comprising polymerizing components of the shaped flexible hot-cure PU foam article of claim 1 to obtain the shaped flexible hot-cure PU foam article.

12. A process for storing and/or transporting a shaped flexible hot-cure PU foam article, the process comprising: (a) reacting at least one polyol and at least one isocyanate to form the shaped flexible hot-cure PU foam article of claim 1; (b) optionally, further processing the shaped flexible hot-cure PU foam article; and (c) finally, compressing the shaped flexible hot-cure PU foam article by at least 20%, optionally vacuum packing and keeping in compressed form by an auxiliary.

13. The process of claim 12, further comprising: adding a sufficient amount of compound(s) of formula (1) in the reacting (a) so that a mass proportion of the compound(s) of formula (1) in a finished polyurethane foam is in a range of from 0.05 to 3.0 wt. %.

14. A process for producing a flexible hot-cure polyurethane foam of claim 1, the process comprising: reacting a mixture comprising a polyol component and a isocyanate component in the presence of a component comprising a blowing agent, a catalyst suitable to catalyze an isocyanate-polyol and/or isocyanate-water reactions and/or isocyanate trimerization, a foam stabilizer, and optionally, a further additive, wherein the foam stabilizer comprises a compound of formula (1):
[R.sup.1.sub.2R.sup.2SiO.sub.1/2].sub.a[R.sup.1.sub.3SiO.sub.1/2].sub.b[R.sup.1.sub.2SiO.sub.2/2].sub.c[R.sup.1R.sup.2SiO.sub.2/2].sub.d[R.sup.3SiO.sub.3/2].sub.e[SiO.sub.4/2].sub.fG.sub.g(1), wherein a is in a range of from 0 to 12, b is in a range of from 0 to 8, c is in a range of from 15 to 300, d is in a range of from 0 to 40, e is in a range of from 0 to 10, f is in a range of from 0 to 5, g is in a range of from greater than 0 to 3, a+b+c+d+e+f+g>23, a+b?2, a+d?1, wherein G is independently a bridging group of formula (2) ##STR00004## wherein R.sup.x is independently a linear organic, branched organic, or an Si containing radical, m is independently 1 or 2, n is independently 1 or 2, n+m=3, y1, y2, and y3 are independently 0 or 1, y1+y2+y3>0 to 3, wherein R.sup.1 is independently a C1 to C16 alkyl radical, C6 to C16 aryl radical, H, or OR.sup.5, R.sup.2 is independently a polyether of formula (3), obtained by polymerizing at least one alkylene oxide, or an organic radical of formula (4)
R.sup.4O[C.sub.2H.sub.4O].sub.i[C.sub.3H.sub.6O].sub.j[CR.sup.6CR.sup.6.sub.2O].sub.kR.sup.7(3),
O.sub.hR.sup.8(4), wherein h is 0 or 1, i is in a range of from 0 to 150, j is in a range of from 0 to 150, k is in a range of from 0 to 80, p in a range of from 1 to 18, i+j+k?3, R.sup.3 is independently an alkyl radical or aryl radicals, either or which is optionally substituted with one or more hetero atoms, R.sup.4 is a divalent organic radical, R.sup.5 is independently a C1 to C16 alkyl radical or C6 to C16 aryl radical, R.sup.6 is independently a C1 to C16 alkyl radical, optionally comprising an ether or halogen substitution, a C6 to C18 aryl radical, optionally comprising an ether, or H, R.sup.7 is independently H, alkyl, C(O)R.sup.9, C(O)OR.sup.9 or C(O)NHR.sup.9, optionally comprising a hetero atom substitution, R.sup.8 is independently an alkyl radical or aryl radical, optionally comprising an OH, ether, epoxide, ester, amine or/and halogen, R.sup.9 is independently a C1 to C16alkyl radical or C6 to C16 aryl radical.

15. A flexible hot-cure polyurethane foam, obtainable by the process of claim 14.

16. A mattress or cushion comprising the flexible hot-cure PU foam of claim 14.

17. The article of claim 1, which is a mattress.

18. The article of claim 1, which is a cushion.

19. The article of claim 1, wherein, in the compound of formula (1), a+b+c+d+e+f+g>40.

Description

EXAMPLES

GPC Measurements of Foam Stabilizers

[0215] The polydispersity and the molar mass averages M.sub.n and M.sub.w of the non-inventive and inventive foam stabilizers were determined by gel permeation chromatography (GPC) based on ISO 13885-1:2020 under the following conditions: separation column combination SDV 1000/10000 ? with precolumn (length: 65 cm, column temperature: 30? C.), THF as mobile phase, flow rate: 1 ml/min, sample concentration: 10 g/L, injection volume 20 ?l, refractive index (RI) detector (30? C.), calibration with polystyrene (162-2520000 g/mol). The obtained values are polystyrene molar mass equivalents.

Physical Properties of the Flexible PU Foams:

[0216] The flexible PU foams produced were assessed according to the following physical properties a) to g): [0217] a) Rise time: The period of time between the end of mixing of the reaction components and the blow-off of the polyurethane foam. [0218] b) Rise height or foam height: the height of the free-risen foam formed after 3 minutes. Foam height is reported in centimetres (cm). [0219] c) Settling of the foam at the end of the rise phase: The settling is calculated from the difference of the foam height after direct blow-off and 3 minutes after foam blow-off. The foam height is measured at the maximum in the middle of the foam crest by means of a needle secured to a centimetre scale. A negative value here describes settling of the foam after blow-off; a positive value correspondingly describes further rise of the foam. [0220] d) Number of cells per cm (cell count): This is determined visually on a cut surface (measured according to DIN EN 15702). [0221] e) Foam density (FD): Determined as described in ASTM D 3574-11 under Test A by measuring the core density. Foam density is reported in kg/m. [0222] f) Porosity determined by the airflow method: In the airflow method in accordance with ASTM D 3574 (2011-00), the volume of air that flows through a defined foam specimen in a particular period of time on application of a pressure differential is determined. For this purpose, 12 test specimens having dimensions of 5 cm?5 cm?2.5 cm were cut out of each of the finished foams transverse to the direction of rise of the foam, and successively inserted into an analytical instrument constructed for this method. The construction of this instrument is described in ASTM D 3574 (2011-00). The analytical instrument generates an air pressure differential of 125 Pa between the inside of the instrument and the surrounding atmosphere by sucking just enough air in through the test specimen for the differential to be kept constant. The air flow through the test specimen is thus a measure of the porosity of the foam. Values in the range from 0-6.5 scfm (standard cubic feet per min) were measured, with lower values within the interval characterizing a more tight foam and higher values a more open foam. [0223] g) Result of the rolling test: This specific test is described in detail below.

[0224] For the sake of completeness, the measurement principle of DIN EN ISO 16000-9:2008-04 is also elucidated hereinafter.

[0225] The materials are characterized here regarding the type and the amount of the organic substances outgassable therefrom. The analysis method serves to ascertain emissions from materials that are used in furniture and mattresses. This is done by using test chambers to measure the emissions.

Analysis:

Test Specimen: Sample Preparation, Sampling and Specimen Dimensions

[0226] The reaction mixture is introduced into a PE plastic bag which is open at the top. After the foam has risen and blown off, the PE bag is closed 3 min after the blow-off. The foam is stored in this way at room temperature for 12 hours in order to enable complete reaction, but simultaneously in order to prevent premature escape of VOCs. Subsequently, the PE bag is opened and a 7 cm?7 cm?7 cm cube is taken from the centre of the foam block and immediately wrapped in aluminium foil and sealed airtight in a PE bag. It was then transported to the analytical laboratory, and the foam cube was introduced into a cleaned 30 l glass test chamber. The conditions in the test chamber were controlled climatic conditions (temperature 21? C., air humidity 50%). Half the volume of the test chamber is exchanged per hour. After 24 hours, samples are taken from the test chamber air. Tenax adsorption tubes serve to absorb the VOCs. The Tenax tube is then heated, and the volatile substances released are cryofocused in a cold trap of a temperature-programmable evaporator with the aid of an inert gas stream. After the heating phase has ended, the cold trap is rapidly heated to 280? C. The focused substances vaporize in the process. They are subsequently separated in the gas chromatography separation column and detected by mass spectrometry. Calibration with reference substances permits a semi-quantitative estimate of the emission, expressed in ?g/m.sup.3. The quantitative reference substance used for the VOC analysis (VOC value) is toluene. Signal peaks can be assigned to substances using their mass spectra and retention indices. The following equipment is used for the analysis: Gerstel, D-45473 M?hlheim an der Ruhr, Eberhard-Gerstel-Platz 1, Germany, TDS-3/KAS-4, Tenax? desorption tubes, Agilent Technologies 7890A (GC)/5975C (MS), column: HP Ultra2 (50 m, 0.32 mm, 0.52 ?m), carrier gas: helium. More specific procedural instructions can be taken from DIN EN ISO 16000-9:2008-04.

[0227] The analytical principles of VDA 278 are also described hereinbelow for the sake of completeness.

VDA 278 Analytical Principles:

[0228] The materials are characterized regarding the type and the amount of the organic substances outgassable therefrom. To this end, two semi-quantitative empirical values are determined to estimate the emission of volatile organic compounds (VOC value) and also the proportion of condensable substances (fogging value). Individual substances of the emission are also determined. In the analysis, the samples are thermally extracted and the emissions are separated by gas chromatography and detected by mass spectrometry. The overall concentrations thus obtained for the VOC fraction are arithmetically converted into toluene equivalents and provide the VOC value as a result; the FOG fraction is represented in hexadecane equivalents and provides the FOG value.

[0229] The analytical method serves to determine emissions from non-metallic materials used for moulded parts in motor vehicles; they also include foams.

[0230] In thermal desorption analysis (TDS), small amounts of material are heated up in a desorption tube in a defined manner and the volatile substances which are emitted in the course of heating are cryofocused by means of an inert gas stream in a cold trap of a temperature-programmable vaporizer. After the heating phase has ended, the cold trap is rapidly heated to 280? C. The focused substances vaporize in the process. They are subsequently separated in the gas-chromatographic separation column and detected by mass spectrometry. Calibration with reference substances permits a semi-quantitative estimate of the emission, expressed in ?g/g. The quantitative reference substances used are toluene for the VOC analysis (VOC value) and n-hexadecane for the fogging value. Signal peaks can be assigned to substances using their mass spectra and retention indices. Source: VDA 278/10.2011, www.vda.de

[0231] Described below is the rolling deformation test which makes it possible to test dimensional recovery after compression in the context of the present invention.

Rolling Deformation Test (Rolling Test for Short)

Objective:

[0232] The test has for its object to simulate the conditions of rolled mattresses in the laboratory. Since there is no meaningful industry standard for this a novel test was developed which simulates the rolling-up of mattress foams on a small scale.

Sample Preparation:

[0233] Test specimens having dimensions of 12 cm (width), 16 cm (length) and 2.5 cm (thickness) are cut out of the flexible PU foam blocks as obtained from manual foaming for example, using a band saw. A central position in the foam blocks from manual foaming is selected. The test specimen is cut out such that the rise direction of the foam during production is at right angles to the length and width of the test specimen. Test specimens are marked with a felt pen.

Test Procedure:

[0234] The test specimen is compressed with a thin metal rod of diameter 5-8 mm (e.g. metal ballpoint pen) at a 12 cm edge. The foam test specimen is then rolled up around this metal rod by hand. This significantly compresses the foam, forming a roll having a diameter of about 3-4 cm. This roll is held manually in this compressed state and pushed completely into a cardboard tube. The cardboard tube has an internal diameter of 4 cm and a length of at least 13 cm. As soon as the rolled-up foam is fully inserted in the tube the metal rod is removed. To minimize friction during removal the metal rod may be lightly greased before the rolling of the foam. The foam then fills the volume of the tube. The compression of the foam in the centre is much more severe than at the edge of the tube. The roll is then stored under controlled, constant conditions (temperature: 21? C., atmospheric humidity: 60%) for 7 days. After 168 hours the foam is manually removed from the tube and placed on an even surface, and the unrolling of the foam is observed. The expansion of the foam must not be disturbed or influenced.

Evaluation:

[0235] The shaped flexible PU foam article is left to expand for 10 minutes. The test specimens are then evaluated. The most important criterion is whether the foam has completely recovered its original thickness orespecially at the more severely compressed edgestill has compression zones. In some cases, a groove from the compression is also apparent on the surface of the test specimen. Very poor test specimens remain rolled up at one end. A slight bend in the test specimen after expansion is normal and is not considered in the assessment. The following grades were used for the evaluation: [0236] +++: Test specimen has fully unrolled, no compression lines or compressions apparent whatsoever, expansion occurs rapidly and is already complete after 5 min. [0237] ++: The test specimen has regained a thickness of 2.5 cm at all sites. No indentations and grooves remain visible at the surface after 10 minutes (particularly at the more severely compressed end). [0238] +: The test specimen has regained a thickness of 2.5 cm at all sites. However, slight indentations and grooves remain visible at the surface (particularly at the more severely compressed end). [0239] 0: The test specimen exhibits a slight compression at the more severely compressed end. The thickness there is more than 2.0 cm but less than 2.5 cm. An indentation is clearly visible at this end. [0240] ?: Test specimen exhibits a slight compression at the more severely compressed end. The thickness of the sample there is more than 1 cm but still considerably less than 2.0 cm. [0241] ??: Test specimen exhibits a severe compression at the more severely compressed end. The thickness of the sample there is less than 1 cm. The sample is still partly rolled up at this end. [0242] ???: Test specimen remains rolled up and compressed at the more severely compressed end.

[0243] The evaluation is preferably performed by at least two people. The results are documented. In the context of the present invention the evaluation was carried out by four people who arrived at consistent results.

Deficiencies and Constraints of the Test:

[0244] Correct dimensions of the test specimen and uniform rolling must be ensured in the test. The foam test specimen must have constant cell structure parameters, i.e. in particular a constant cell size and a constant air permeability. The metal rod must not be excessively greased so that no grease penetrates into the sample. Constant storage conditions must be maintained. Test specimens given the various evaluation grades must be kept available for comparison.

Precision of the Test:

[0245] Performance of the test with two or more people for evaluation regularly results in consistent assessments. Additionally, in duplicate measurements the same result was regularly confirmed. The test has thus proven reliability.

Hot-Cure Flexible PU FoamFoaming Examples:

Example 1: Production of Hot-Cure Flexible PU Foams (Flexible Slabstock Foam)

[0246] For the performance testing of the inventive compounds of the formula (1), the hot-cure flexible PU foam formulation specified in Table 1 was used.

TABLE-US-00002 TABLE 1 Formulation 1 for hot-cure flexible PU foam production. Formulation 1 Parts by mass (pphp) Polyol 1.sup.1) 100 water 4.00 Tin catalyst.sup.2) 0.20-0.28 TEGOAMIN? DMEA.sup.3) 0.15 FOAM STABILIZER.sup.4) 0.45 Desmodur? T 80.sup.5) 50.0 1) Polyol 1: Voranol? CP 3322 available from Dow Chemical, this is a glycerol-based polyether polyol having an OH number of 48 mg KOH/g and predominantly secondary OH groups, average molar mass = 3500 g/mol. 2) KOSMOS? T9, available from Evonik Industries: tin(II) salt of 2-ethylhexanoic acid. 3) TEGOAMIN? DMEA: dimethylethanolamine, available from Evonik Industries. Amine catalyst for production of polyurethane foams. 4) Foam stabilizer: non-inventive polyether-modified polysiloxane or inventive polyether-modified polysiloxanes, according to formula (1). The polyether-modified polysiloxanes were obtained by the following synthesis procedures:

Foam Stabilizer 1 (Non-Inventive):

[0247] A 1 three-neck flask having a jacketed coil condenser and precision glass stirrer was initially charged with 225 g of a siloxane of the general formula [Me.sub.3SiO.sub.1/2].sub.2 [SiMe.sub.2O.sub.2/2].sub.70[SiMeHO.sub.2/2].sub.4 together with 289 g of an allyl functional polyether of the general formula CH.sub.2?CHCH.sub.2O [C.sub.2H.sub.4O].sub.37[C.sub.3H.sub.6O].sub.38Me and 87 g of a allyl polyether of the general formula CH.sub.2?CHCH.sub.2O [C.sub.2H.sub.4O].sub.14Me. The mixture was stirred and heated to 90? C. Then 0.3 g of a solution of the Karstedt catalyst in toluene (w (Pt)=2%) was added. An exothermic reaction set in. The reaction mixture was then stirred at 90? C. for four hours. After this reaction time, the SiH functions had been fully converted.

GPC Results

[0248] M.sub.n: 6197 g/mol, M.sub.w: 16690 g/mol, M.sub.w/M.sub.n: 2.69, content (RI)<100 000 g/mol: 99.9%.

Foam Stabilizer 2 (Inventive):

[0249] A 1 l three-neck flask having a jacketed coil condenser and precision glass stirrer was initially charged with 238 g of a siloxane of the general formula [Me.sub.3SiO.sub.1/2].sub.2 [SiMe.sub.2O.sub.2/2].sub.70[SiMeHO.sub.2/2].sub.4 together with 278 g of an allyl functional polyether of the general formula CH.sub.2?CHCH.sub.2O [C.sub.2H.sub.4O].sub.37[C.sub.3H.sub.6O].sub.38Me, 82 g of a allyl polyether of the general formula CH.sub.2?CHCH.sub.2O [C.sub.2H.sub.4O].sub.14Me and 1.2 g 1,7-Octadiene. The mixture was stirred and heated to 90? C. Then 0.3 g of a solution of the Karstedt catalyst in toluene (w (Pt)=2%) was added. An exothermic reaction set in. The reaction mixture was then stirred at 90? C. for four hours. After this reaction time, the SiH functions had been fully converted.

GPC Results

[0250] M.sub.n: 6298 g/mol, M.sub.w: 25216 g/mol, M.sub.w/M.sub.n: 4.00, content (RI)<100 000 g/mol: 95.2%.

Foam Stabilizer 3 (Inventive):

[0251] A 1 l three-neck flask having a jacketed coil condenser and precision glass stirrer was initially charged with 238 g of a siloxane of the general formula [Me.sub.3SiO.sub.1/2].sub.2 [SiMe.sub.2O.sub.2/2].sub.70[SiMeHO.sub.2/2].sub.4 together with 278 g of an allyl functional polyether of the general formula CH.sub.2?CHCH.sub.2O [C.sub.2H.sub.4O].sub.37 [C.sub.3H.sub.6O].sub.38Me, 82 g of a allyl polyether of the general formula CH.sub.2?CHCH.sub.2O [C.sub.2H.sub.4O].sub.14Me and 2.3 g Trimethylolpropane Diallyl Ether 90 from Perstorp (CAS Number-682-09-7). The mixture was stirred and heated to 90? C. Then 0.3 g of a solution of the Karstedt catalyst in toluene (w (Pt)=2%) was added. An exothermic reaction set in. The reaction mixture was then stirred at 90? C. for four hours. After this reaction time, the SiH functions had been fully converted.

GPC Results

[0252] M.sub.n: 6341 g/mol, M.sub.w: 20887 g/mol, M.sub.w/M.sub.n: 3.29, content (RI)<100 000 g/mol: 98.0%.

Foam Stabilizer 4 (Inventive):

[0253] A 1 l three-neck flask having a jacketed coil condenser and precision glass stirrer was initially charged with 238 g of a siloxane of the general formula [Me.sub.3SiO.sub.1/2].sub.2 [SiMe.sub.2O.sub.2/2].sub.70[SiMeHO.sub.2/2].sub.4 together with 278 g of an allyl functional polyether of the general formula CH.sub.2?CHCH.sub.2O [C.sub.2H.sub.4O].sub.37[C.sub.3H.sub.6O].sub.38Me, 82 g of a allyl polyether of the general formula CH.sub.2?CHCH.sub.2O [C.sub.2H.sub.4O].sub.14Me and 2.0 g 1,1,3,3-Tetramethyl-1,3-divinyl-disiloxan (CAS Number: 2627-95-4). The mixture was stirred and heated to 90? C. Then 0.3 g of a solution of the Karstedt catalyst in toluene (w (Pt)=2%) was added. An exothermic reaction set in. The reaction mixture was then stirred at 90? C. for four hours. After this reaction time, the SiH functions had been fully converted.

GPC Results

[0254] M.sub.n: 6373 g/mol, M.sub.w: 24371 g/mol, M.sub.w/M.sub.n: 3.82, content (RI)<100 000 g/mol: 95.7%.

[0255] .sup.5) tolylene diisocyanate T 80 (80% 2,4 isomer, 20% 2,6 isomer) from Covestro, 3 mPa-s, 48% NCO, functionality 2.

[0256] 400 g of polyol was used in each foaming operation; the other formulation constituents were recalculated accordingly. 1.00 part of a component denoted 1.00 g of this substance per 100 g of polyol for example.

[0257] The foaming was carried out by what is called manual mixing. Formulation 1 as specified in table 1 was used. To this end, a paper cup was charged with polyol, the respective amine catalyst mixture, the tin catalyst tin(II) 2-ethylhexanoate, water and a foam stabilizer, and the contents were mixed at 1000 rpm for 60 seconds with a disc stirrer. After the first stirring the isocyanate (TDI) was added to the reaction mixture and stirred at 2500 rpm for 7 s and then immediately transferred into a paper-lined box (30 cm?30 cm base area and 30 cm height). After being poured in, the foam rose in the foaming box. In the ideal case, the foam blew off on attainment of the maximum rise height and then fell back slightly. This opened the cell membranes of the foam bubbles and an open-pore cell structure of the foam was obtained. To assess the properties, the following characteristic parameters were determined: rise time, rise height and settling of the foam after the end of the rise phase.

[0258] Defined foam bodies were cut out of the resulting hot-cure flexible PU foam blocks and were analysed further. The following physical properties were determined on the test specimens: cell count, porosity by the air flow method, foam density (FD) and rolling deformation at room temperature.

[0259] The results of the influence of the compounds according to the invention regarding foaming and the physical properties of the resulting hot-cure flexible PU foams are compiled in the following tables. Hot-cure flexible PU foams were produced with a standard flexible foam stabilizer (foam stabilizer 1) and with the inventive flexible foam stabilizers 2, 3 and 4.

TABLE-US-00003 TABLE 2 Reference foams (obtained using foam stabilizer 1) and foams with foam stabilizer 2. #1 #2 #3 Foam Foam Foam stabilizer 1 stabilizer 1 stabilizer 1 #4 #5 #6 (non- (non (non Foam Foam Foam inventive) inventive) inventive) stabilizer 2 stabilizer 2 stabilizer 2 Amount of Sn 0.20 pphp 0.24 pphp 0.28 pphp 0.20 pphp 0.24 pphp 0.28 pphp catalyst Amount of 0.45 pphp 0.45 pphp 0.45 pphp 0.45 pphp 0.45 pphp 0.45 pphp stabilizer Rise time (s) 108 99 91 109 99 92 Rise height 33.8 34.4 36.8 34.3 34.4 35.2 (cm) Settling (cm) ?0.5 ?0.2 0.0 ?0.2 ?0.1 0.0 Cells (per cm) 13 13 13 13 13 13 Density 23.6 23.1 22.8 23.4 23.1 22.5 (kg/m.sup.3) Porosity 3.58 2.23 1.37 3.12 2.01 1.67 (SCFM) Roll + ? ? ? ? ? + + + + ? deformation (7 d, 21? C.)

TABLE-US-00004 TABLE 3 Foams with foam stabilizers 3 and 4. #7 #8 #9 #10 #11 #12 Foam Foam Foam Foam Foam Foam stabilizer 3 stabilizer 3 stabilizer 3 stabilizer 4 stabilizer 4 stabilizer 4 Amount of Sn 0.20 pphp 0.24 pphp 0.28 pphp 0.20 pphp 0.24 pphp 0.28 pphp catalyst Amount of 0.45 pphp 0.45 pphp 0.45 pphp 0.45 pphp 0.45 pphp 0.45 pphp stabilizer Rise time (s) 108 99 92 108 98 92 Rise height 33.5 34.9 36.2 34.1 34.3 35.6 (cm) Settling (cm) ?0.2 0.0 0.0 ?0.2 ?0.1 0.0 Cells (per cm) 13 13 13 13 13 13 Density 23.5 23.2 22.9 23.1 23.0 22.4 (kg/m.sup.3) Porosity 3.20 2.12 1.45 3.35 2.08 1.75 (SCFM) Roll + + + 0 ? + + + 0 0 deformation (7 d, 21? C.)

[0260] In the evaluation of the results, it must be taken into account that the result of the rolling test depends significantly on the porosity of the foam. For foams having a more closed cell structure generally worse results are obtained than for those foams those having an open cell structure. To obtain complete information about the rolling deformation test performance of the inventive foam stabilizers the screening was performed after adjustment of the foam porosity to different levels. This was achieved by variation of the use level of tin catalyst (KOSMOS? T9) between 0.20 and 0.28 pphp. Foams obtained using the same use level of tin catalyst were compared with each other.

[0261] While the usage of the inventive foam stabilizers 2, 3 and 4 does not show any significant impact on general foam properties like porosity, cell structure or hardness, compared to the non-inventive foam stabilizer 1, it was surprisingly found that the foams obtained using the inventive foam stabilizers show significantly improved results in the recovery after compression over the whole investigated porosity range, as tested by the rolling test. The recovery of the original shape of the test specimens after rolling deformation was improved to a quite crucial degree when comparing foams with similar porosities: e.g. foam #1 and foam #4 were both obtained using 0.20 pphp KOSMOS? T9 and show comparable foam properties, but while foam #1 (using non-inventive foam stabilizer 1) was rated with +in the rolling test (recovery of original sample height, but remaining indentations and grooves after 10 minutes), foam #4 using the inventive foam stabilizer 2 was surprisingly rated significantly better as +++(fully recovered after less than 5 minutes). This improvement stands for a significantly better recovery of the rolled and compressed foam samples. The same significant improvement is also found for the tighter foams obtained using a higher level of KOSMOS? T9 and for the foams obtained using foams stabilizers 3 and 4.

[0262] The hot-cure flexible PU foams according to the invention are also found to have low emissions. This can be seen in the VOC tests according to DIN EN ISO 16000-9:2008-04. It is found here, in a low-emissions formulation, that total emissions are well below the typical limits for TVOC of 500 ?g/m.sup.3. The hot-cure flexible PU foams according to the invention are also suitable to meet the requirements of the VOC and FOG tests according to VDA 278. It is found here, in a low-emissions formulation, that the total emissions found in the VOC and FOG are not increased compared to the reference foams and well below the typical limits for the VOC (100 ?g/g) and FOG (250 ?g/g) values. The foam stabilizers 2, 3 and 4 are thus also highly suitable for use in low-emissions formulations. The results are summarized in table 4.

TABLE-US-00005 TABLE 4 Results of chamber tests according to DIN EN ISO 16000-9: 2008-04 and VDA 278 for a reference hot-cure flexible PU foam obtained using foam stabilizer 1 and a foam using the inventive foam stabilizer 2 based on a low emission formulation. Method Foam stabilizer TVOC DIN EN ISO Foam stabilizer 1 20 ?g/m.sup.3 16000-9: 2008-04 (non-inventive) Foam stabilizer 2 21 ?g/m.sup.3 VDA 278 (VOC) Foam stabilizer 1 <10 ?g/g (non-inventive) Foam stabilizer 2 <10 ?g/g VDA 278 (FOG) Foam stabilizer 1 22 ?g/g (non-inventive) Foam stabilizer 2 17 ?g/g

[0263] The overall advantageousness of the invention has also been confirmed in the case of viscoelastic and hypersoft flexible foams.