PROCESS FOR PRODUCING HIGH-PURITY HYDROSILYLATION PRODUCTS

Abstract

The present invention relates to a process for producing high-purity hydrosilylation products, and also to the products that may be produced by this process and to the use thereof as surfactants.

Claims

1-15. (canceled)

16. A process for producing organically modified polysiloxanes and/or silanes by hydrosilylation, comprising the following steps: a) reacting at least one SiH-functional siloxane and/or silane with at least one unsaturated organic compound in the presence of a noble metal catalyst and optionally in the presence of water; b) optionally performing a distillation; c) performing a separation of solids; wherein magnesium oxide is added as a separate component before, during, and/or after completion of the hydrosilylation reaction.

17. The process of claim 16, wherein the unsaturated organic compound is a terminally unsaturated polyether.

18. The process of claim 16, wherein the unsaturated organic compound is a terminally unsaturated alkene compound, optionally comprising a least one substituent.

19. The process of claim 18, wherein the unsaturated organic compound is selected from the group consisting of: allyl glycidyl ether; glycerol monoallyl ether; allyl glycol; allyloxyethanol; allylanisole; allylphenol; eugenol; hexenol; C6-C20-alkene; undecylenic acid; and vinylcyclohexene monoxide.

20. The process according of claim 16, wherein the unsaturated organic compound comprises one or more internal double bonds.

21. The process of claim 16, wherein the noble metal catalyst is a compound or complex comprising a metal selected from the group consisting of: platinum; palladium; rhodium; ruthenium; iridium; and osmium.

22. The process of claim 16, wherein the magnesium oxide has a purity of >85%.

23. The process of claim 22, wherein the magnesium oxide comprises a bulk density of <1 g/cm.sup.3.

24. The process of claim 22, wherein the particle size of the magnesium oxide is <10 mesh.

25. The process claim 16, wherein the magnesium oxide is present at 0.01% to 5% by weight based on the entirety of the reaction mass, and wherein the magnesium oxide is added before, during and/or after the noble metal-catalyzed hydrosilylation.

26. The process of claim 16, wherein the hydrosilylation is carried out under an inert atmosphere.

27. The process of claims 16, wherein the hydrosilylation is carried out in the presence of water which is removed by distillation after the reaction, and wherein the amount of water is 0.05% to 50% by weight based on the total reaction mass.

28. A hydrosilylation product, obtained by the process of claim 16.

29. The hydrosilylation product of claim 28, comprising an organically modified polysiloxane and/or silane.

30. The hydrosilylation product of claim 28, comprising a polyether siloxane.

31. The hydrosilylation product of claim 28, comprising the structure of formula (I):
M.sub.aM′.sub.bM″.sub.cD.sub.dD′.sub.eD″.sub.fT.sub.gQ.sub.h   formula (I) wherein: M=[R.sup.1.sub.3SiO.sub.1/2]; M′=[R.sup.2R.sup.1.sub.2SiO.sub.1/2]; M″=[R.sup.3R.sup.1.sub.2SiO.sub.1/2]; D=[R.sup.1.sub.2SiO.sub.2/2]; D′=[R.sup.2R.sup.1SiO.sub.2/2]; D″=[R.sup.3R.sup.1SiO.sub.2/2]; T=[R.sup.1SiO.sub.3/2]; Q=[SiO.sub.4/2]; a=0-20; b=0-20; c=0-20; d=0-1000; e=0-30; f=0-30; g=0-20; h=0-20; with the proviso that the sum of a+b+c+d+e+f+g+h≥3; and the sum of b+c+e+f must be ≥1; and wherein: R.sup.1=independently identical or different hydrocarbon radicals having 1-7 carbon atoms or H; R.sup.2=independently identical or different polyether radicals; R.sup.3=independently identical or different hydrocarbon radicals having 8-20 carbon atoms and which may also comprise heteroatoms and may have further substitution.

32. The hydrosilylation product of claim 28, wherein: a=0-10; b=0-10; c=0-10; d=0-500; e=1-15; f=0-15; g=0-10; h=0-15.

33. The hydrosilylation product of claim 28, wherein: a=2; b=0 or 2; c=0 or 2; d=0-200; e=1-10; f=0-10; g=0-5; h=0-5.

34. The hydrosilylation product of claim 28, wherein R.sup.3 is a SiC-bonded radical resulting from alkynediol and alkoxylates thereof.

35. A cleaning and/or care formulation suitable for cleaning and/or care of hard surfaces and/or suitable for cleaning, treatment and post-treatment of textiles, or cosmetic products, comprising the hydrosilylation product of claim 28.

Description

EXAMPLES

Example 1a: Synthesis of an HMTS-Based Polyether Siloxane (Comparative Example)

[0102] In a 1 L flange flask provided with a dropping funnel with pressure equalization tube, thermometer, jacketed coil condenser and Sigma stirrer, 226.6 g of an allyl polyether (ethoxylate of allyl alcohol having an IV of 63 g iodine/100 g) is initially charged and the mixture heated to 90° C. with stirring and argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=4 ppm Pt). Subsequently, heptamethyltrisiloxane with a mass of 100 g (HMTS with SiH=4.50 mol/kg) is added dropwise over ca. 30 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion specified in Table 1, determined by the sodium butoxide method. The mixture is then distilled for 1 h at 120° C. and p<10 mbar in order to remove volatile product constituents and then filtered through a layer filter.

Example 1b: Synthesis of an HMTS-Based Polyether Siloxane (Comparative Example)

[0103] The example was carried out analogously to Example 1a with the difference that, after addition of the allyl polyether, the amount of adsorbent (I) (based on the total mixture) specified in Table 1 was added.

Example 1c: Synthesis of an HMTS-Based Polyether Siloxane (Comparative Example)

[0104] The example was carried out analogously to Example 1a with the difference that, after addition of the allyl polyether, the amounts of adsorbent (I) and water (each based on the total mixture) specified in Table 1 were also added.

Example 1d: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0105] The example was carried out analogously to Example 1a with the difference that, after addition of the allyl polyether, the amount of adsorbent (II) (based in each case on the total mixture) specified in Table 1 was also added.

Example 1e: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0106] The example was carried out analogously to Example 1a with the difference that, after addition of the allyl polyether, the amount of adsorbent (III) (based in each case on the total mixture) specified in Table 1 was also added.

Example 1f: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0107] The example was carried out analogously to Example 1a with the difference that, after addition of the allyl polyether, the amount of adsorbent (IV) (based in each case on the total mixture) specified in Table 1 was also added.

Example 1g: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0108] The example was carried out analogously to Example 1a with the difference that, after addition of the allyl polyether, the amounts of adsorbent (II) and water (each based on the total mixture) specified in Table 1 were also added.

Example 1h: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0109] The example was carried out analogously to Example 1a with the difference that, after addition of the allyl polyether, the amounts of adsorbent (III) and water (each based on the total mixture) specified in Table 1 were also added.

Example 1i: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0110] The example was carried out analogously to Example 1a with the difference that, after addition of the allyl polyether, the amounts of adsorbent (IV) and water (each based on the total mixture) specified in Table 1 were also added.

Example 1 j: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0111] In a 1 L flange flask provided with a dropping funnel with pressure equalization tube, thermometer, jacketed coil condenser and Sigma stirrer, 367.9 g of an allyl polyether (ethoxylate of allyl alcohol having an IV of 63 g iodine/100 g) is initially charged and the mixture heated to 90° C. with stirring and argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=4 ppm Pt). Subsequently, heptamethyltrisiloxane with a mass of 150 g (HMTS with SiH=4.87 mol/kg) is added dropwise over ca. 30 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion specified in Table 1, determined by the sodium butoxide method. Subsequently, 0.65 g of adsorbent (II) is fed to the mixture and is then distilled for 1 h at 120° C. and p<10 mbar in order to remove volatile product constituents and is then filtered through a layer filter.

Example 1k: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0112] The example was carried out analogously to Example 1j with the difference that, after hydrosilylation was complete, the amounts of adsorbent (II) and water (each based on the total mixture) specified in Table 1 were added.

Example 1l: Synthesis of an HMTS-Based Polyether Siloxane (Inventive)

[0113] In a 1 L flange flask provided with a dropping funnel with pressure equalization tube, thermometer, jacketed coil condenser and Sigma stirrer, 367.9 g of an allyl polyether (ethoxylate of allyl alcohol having an IV of 63 g iodine/100 g) is initially charged and the mixture heated to 90° C. with stirring and argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=4 ppm Pt). Subsequently, heptamethyltrisiloxane with a mass of 75 g (HMTS with SiH=4.87 mol/kg) is added dropwise over ca. 15 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 0.5 h and then the SiH conversion is determined. This gave the SiH conversion (1) specified in Table 1, determined by the sodium butoxide method. Subsequently, 0.65 g of adsorbent (II) is fed to the mixture. Subsequently, heptamethyltrisiloxane with a mass of 75 g (HMTS with SiH=4.87 mol/kg) is added dropwise over ca. 15 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 1.0 h and then the SiH conversion (2) is determined. This gave the SiH conversion specified in Table 1, determined by the sodium butoxide method. The mixture is then distilled for 1 h at 120° C. and p<10 mbar in order to remove volatile product constituents and then filtered through a layer filter.

TABLE-US-00001 TABLE 1 Additives and analytical data for Examples 1a-l SiH conversion Adsorbent Water Hazen Pt content Example [%] [%] [%] value [ppm] 1a 99.2 0 0 80 4.0 1b 99.8 0.5 0 48 2.0 1c 99.8 0.5 0.5 30 1.6 1d 99.9 0.125 0 14 0.4 1e 99.8 0.125 0 48 1.8 1f 99.5 0.125 0 32 1.0 1g 99.9 0.125 0.5 13 0.4 1h 99.9 0.125 0.5 65 3.0 1i 99.9 0.125 0.5 16 0.5 1j 99.7 0.125 0 19 0.5 1k 99.9 0.125 0.125 15 0.5 1l   99.9 (1) 0.125 0 17 0.4   99.9 (2)

Example 2a: Synthesis of a C16-Alpha-Olefin-Based Polyalkylsiloxane (Comparative Example)

[0114] In a flange flask provided with a dropping funnel with pressure equalizing tube, thermometer and Sigma stirrer, 250 g of a comb-positioned SiH siloxane

[0115] (SiH=6.88 mol/kg, M.sub.2D.sub.5.4D.sup.H.sub.6.6) are initially charged and the mixture is heated with stirring and argon supply to 90° C. The Karstedt catalyst (c (batch)=3 ppm Pt) is then added using a micropipette. Subsequently, the C16 alpha-olefin with a mass of 443.9 g is added dropwise over ca. 40 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion specified in Table 2, determined by the sodium butoxide method.

Example 2b: Synthesis of a C16-Alpha-Olefin-Based Polyalkylsiloxane (Inventive)

[0116] The example was carried out analogously to Example 2a with the difference that, after addition of the siloxane, the amounts of adsorbent (IV) and water (each based on the total mixture) specified in Table 2 were also added.

Example 2c: Synthesis of a C16-Alpha-Olefin-Based Polyalkylsiloxane (Inventive)

[0117] The example was carried out analogously to Example 2a with the difference that, after addition of the allyl polyether, the amount of adsorbent (III) (based in each case on the total mixture) specified in Table 1 was also added.

Example 2d: Synthesis of a C16-Alpha-Olefin-Based Polyalkylsiloxane (Inventive)

[0118] The example was carried out analogously to Example 2a with the difference that, after addition of the siloxane, the amounts of adsorbent (III) and water (each based on the total mixture) specified in Table 2 were also added.

TABLE-US-00002 TABLE 2 Additives and analytical data for Examples 2a-d SiH conversion Adsorbent Water Hazen Pt content Example [%] [%] [%] value [ppm] 2a 95.9 0 0 38 2.0 2b 93.8 0.25 0.25 10 0.6 2c 93.0 0.125 0 7 0.5 2d 94.8 0.125 0.5 26 1.0

Example 3a: Synthesis of a Comb-Positioned Polyether Siloxane (Comparative Example)

[0119] In a 1 L flange flask provided with a dropping funnel with pressure equalization tube, thermometer, jacketed coil condenser and Sigma stirrer, 202.3 g of a methylated allyl polyether (ethoxylate of allyl alcohol having an IV of 63.5 g iodine/100 g, the terminal OH group of which was methylated) is initially charged and the mixture heated to 90° C. with stirring and argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=4 ppm Pt). Subsequently, the comb-positioned SiH siloxane with a mass of 250 g (SiH=1.50 mol/kg, M.sub.2D.sub.6D.sup.H.sub.1) is added dropwise over ca. 30 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 5 h and then the SiH conversion is determined. This gave the SiH conversion specified in Table 3, determined by the sodium butoxide method. The mixture is then distilled for 2 h at 120° C. and p<10 mbar in order to remove volatile product constituents and then filtered through a layer filter.

Example 3b: Synthesis of a Comb-Positioned Polyether Siloxane (Inventive)

[0120] The example was carried out analogously to Example 3a with the difference that, after addition of the allyl polyether, the amounts of adsorbent (III) and water (each based on the total mixture) specified in Table 3 were also added.

Example 3c: Synthesis of a Comb-Positioned Polyether Siloxane (Inventive)

[0121] The example was carried out analogously to Example 3a with the difference that, after addition of the allyl polyether, the amounts of adsorbent (IV) and water (each based on the total mixture) specified in Table 3 were also added.

Example 3d: Synthesis of a Comb-Positioned Polyether Siloxane (Inventive)

[0122] The example was carried out analogously to Example 3a with the difference that, after addition of the allyl polyether, the amounts of adsorbent (IV) and water (each based on the total mixture) specified in Table 3 were also added.

Example 3e: Synthesis of a Comb-Positioned Polyether Siloxane (Inventive)

[0123] The example was carried out analogously to Example 3a with the difference that, after addition of the allyl polyether, the amount of adsorbent (IV) (based in each case on the total mixture) specified in Table 3 was also added.

Example 3f: Synthesis of a Comb-Positioned Polyether Siloxane (Inventive)

[0124] In a 1 L flange flask provided with a dropping funnel with pressure equalization tube, thermometer, jacketed coil condenser and Sigma stirrer, 202.3 g of a methylated allyl polyether (ethoxylate of allyl alcohol having an IV of 63.5 g iodine/100 g, the terminal OH group of which was methylated) is initially charged and the mixture heated to 90° C. with stirring and argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=4 ppm Pt). Subsequently, the comb-positioned SiH siloxane with a mass of 250 g (SiH=1.50 mol/kg, M.sub.2D.sub.6D.sup.H.sub.1) is added dropwise over ca. 30 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion specified in Table 1, determined by the sodium butoxide method. Subsequently, 0.57 g of adsorbent (IV) is fed to the mixture and the mixture is then distilled for 1 h at 120° C. and p<10 mbar in order to remove volatile product constituents and is then filtered through a layer filter.

Example 3g: Synthesis of a Comb-Positioned Polyether Siloxane (Inventive)

[0125] In a 1 L flange flask provided with a dropping funnel with pressure equalization tube, thermometer, jacketed coil condenser and Sigma stirrer, 202.3 g of a methylated allyl polyether (ethoxylate of allyl alcohol having an IV of 63.5 g iodine/100 g, the terminal OH group of which was methylated) is initially charged and the mixture heated to 90° C. with stirring and argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=4 ppm Pt). Subsequently, the comb-positioned SiH siloxane with a mass of 250 g (SiH=1.50 mol/kg, M.sub.2D.sub.6D.sup.H.sub.1) is added dropwise over ca. 30 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion specified in Table 1, determined by the sodium butoxide method. Subsequently, 0.57 g of adsorbent (III) is fed to the mixture and the mixture is then distilled for 1 h at 120° C. and p<10 mbar in order to remove volatile product constituents and is then filtered through a layer filter.

Example 3h: Synthesis of a Comb-Positioned Polyether Siloxane (Inventive)

[0126] In a 1 L flange flask provided with a dropping funnel with pressure equalization tube, thermometer, jacketed coil condenser and Sigma stirrer, 202.3 g of a methylated allyl polyether (ethoxylate of allyl alcohol having an IV of 63.5 g iodine/100 g, the terminal OH group of which was methylated) is initially charged and the mixture heated to 90° C. with stirring and argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=4 ppm Pt). Subsequently, the comb-positioned SiH siloxane having a mass of 125 g (50% of the siloxane total mass) (SiH=1.50 mol/kg, M.sub.2D.sub.6D.sup.H.sub.1) is added dropwise over ca. 15 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion (1) specified in Table 1, determined by the sodium butoxide method. Subsequently, 0.57 g of adsorbent (III) is fed to the mixture and then the comb-positioned SiH siloxane having a mass of 125 g (50% of the siloxane total mass) (SiH=1.50 mol/kg, M.sub.2D.sub.6D.sup.H.sub.1) is added dropwise over ca. 15 minutes via the dropping funnel such that the temperature of the reaction mixture does not exceed 115° C. After addition is complete, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion (2) specified in Table 1, determined by the sodium butoxide method. The mixture is then distilled for 1 h at 120° C. and p<10 mbar in order to remove volatile product constituents and then filtered through a layer filter.

TABLE-US-00003 TABLE 3 Additives and analytical data for Examples 3a-h SiH conversion Adsorbent Water Hazen Pt content Example [%] [%] [%] value [ppm] 3a >99% 0 0 22 1.1 3b >99% 0.125 0.5 16 0.8 3c 98.8%  0.125 0.5 16 0.7 3d >99% 0.025 0.5 15 0.7 3e >99% 0.025 0 8 0.2 3f >99% 0.125 0 14 0.2 3g >99% 0.125 0 11 0.2 3h  .sup. >99.9% (1) 0.125 0 12 0.2  .sup. 98.4% (2)

Example 4a: Synthesis of a Linear Polyether Siloxane (Comparative Example)

[0127] In a 1 L flange flask provided with a dropping funnel with pressure equalizing tube, thermometer, jacketed coil condenser and Sigma stirrer, 381.8 g of an allyl polyether (copolymer of EO (60%) and PO (40%) on allyl alcohol having an IV of 49 g iodine/100 g) and 300 g of siloxane (SiH value=1.82 mol/kg, M.sub.2.sup.HD.sub.13) are successively initially charged and heated to 55° C. with stirring and under argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=6 ppm Pt). The mixture is heated to 90° C. and where appropriate counter-cooled such that a temperature of 110° C. is not exceeded. Subsequently, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion specified in Table 4, determined by the sodium butoxide method. The mixture is then distilled for 1 h at 120° C. and p<10 mbar in order to remove volatile product constituents and then filtered through a layer filter.

Example 4b: Synthesis of a Linear Polyether Siloxane (Inventive)

[0128] The example was carried out analogously to Example 4a with the difference that, after addition of the allyl polyether and siloxane, the amount of adsorbent (II) and water (each based on the total mixture) specified in Table 4 were also added.

Example 4c: Synthesis of a Linear Polyether Siloxane (Inventive)

[0129] The example was carried out analogously to Example 4a with the difference that, after addition of the allyl polyether and siloxane, the amount of adsorbent (III) and water (each based on the total mixture) specified in Table 4 were also added.

Example 4d: Synthesis of a Linear Polyether Siloxane (Inventive)

[0130] The example was carried out analogously to Example 4a with the difference that, after addition of the allyl polyether and siloxane, the amount of adsorbent (IV) and water (each based on the total mixture) specified in Table 4 were also added.

Example 4e: Synthesis of a Linear Polyether Siloxane (Inventive)

[0131] The example was carried out analogously to Example 4a with the difference that, after addition of the allyl polyether and siloxane, the amounts of adsorbent (II) and water (each based on the total mixture) specified in Table 4 were also added.

Example 4f: Synthesis of a Linear Polyether Siloxane (Inventive)

[0132] The example was carried out analogously to Example 4a with the difference that, after addition of the allyl polyether and siloxane, the amounts of adsorbent (III) and water (each based on the total mixture) specified in Table 4 were also added.

Example 4g: Synthesis of a Linear Polyether Siloxane (Inventive)

[0133] The example was carried out analogously to Example 4a with the difference that, after addition of the allyl polyether and siloxane, the amounts of adsorbent (IV) and water (each based on the total mixture) specified in Table 4 were also added.

Example 4h: Synthesis of a Linear Polyether Siloxane (Inventive)

[0134] In a 1 L flange flask provided with a dropping funnel with pressure equalizing tube, thermometer, jacketed coil condenser and Sigma stirrer, 381.8 g of an allyl polyether (copolymer of EO (60%) and PO (40%) on allyl alcohol having an IV of 49 g iodine/100 g) and 300 g of siloxane (SiH value=1.82 mol/kg, M.sub.2.sup.HD.sub.13) are successively initially charged and heated to 55° C. with stirring and under argon supply. The Karstedt catalyst is then added using a micropipette (c (batch)=6 ppm Pt). The mixture is heated to 90° C. and where appropriate counter-cooled such that a temperature of 110° C. is not exceeded. Subsequently, the mixture is further stirred at 110° C. for 1 h and then the SiH conversion is determined. This gave the SiH conversion specified in Table 4, determined by the sodium butoxide method. The adsorbent (II) is then added in the amount as can be found in Table 4. The mixture is then distilled for 1 h at 120° C. and p<10 mbar in order to remove volatile product constituents and then filtered through a layer filter.

TABLE-US-00004 TABLE 4 Additives and analytical data for Examples 4a-h SiH conversion Adsorbent Water Hazen Pt content Example [%] [%] [%] value [ppm] 4a 99.9 0 0 91 4.0 4b 99.9 0.125 0 13 0.6 4c 99.9 0.125 0 35 1.9 4d 99.9 0.125 0 23 1.0 4e 99.9 0.125 0.5 18 0.9 4f 99.9 0.125 0.5 23 1.2 4g 99.9 0.125 0.5 15 0.8 4h 99.9 0.125 0 18 1.0

Conclusion

[0135] On consideration of the Hazen colour numbers and Pt contents specified in Tables 1-4, it is evident to a person skilled in the art that the best products having the lowest Hazen colour numbers and lowest Pt contents were obtained by the process according to the invention.

[0136] Carrying out the process in the presence of magnesium oxide results in higher quality products or products of comparable quality than when a combination of water and magnesium oxide is used.

[0137] Since water possibly present after completion of the reaction has to be distilled off, it is preferably processed without addition of water.

[0138] The addition of magnesium oxide before, during or after completion of the hydrosilylation results in comparable product qualities which enables the user flexible use of the adsorbent in the respective specific application.