Synergistic combinations of platinum compounds and rhodium compounds as catalysts in hydrosilylations

Abstract

Composition for use as catalyst in hydrosilylations, comprising at least one platinum compound selected from the group consisting of Pt[(Me.sub.2SiCH═CH.sub.2).sub.2O].sub.2 and Pt.sub.2[(Me.sub.2SiCH═CH.sub.2).sub.2O].sub.3 and at least one rhodium compound selected from the group consisting of Rh(acac)(CO).sub.2, Rh.sub.2(CO).sub.4Cl.sub.2, [Rh(cod)Cl].sub.2, Rh(acac)(cod), RhH(CO)(PPh.sub.3).sub.3, Rh(CO)(PPh.sub.3)(acac), RhCl(CO)(PPh.sub.3).sub.2, and Rh-2-ethylhexanoate at a molar ratio of Pt/Rh in the range of 0.1 to 100.

Claims

1. A composition comprising at least one platinum compound selected from the group consisting of Pt[(Me.sub.2SiCH═CH.sub.2).sub.2O].sub.2 and Pt.sub.2[(Me.sub.2SiCH═CH.sub.2).sub.2O].sub.3, and at least one rhodium compound selected from the group consisting of Rh.sub.2(CO).sub.4Cl.sub.2, [Rh(cod)Cl].sub.2, Rh(acac)(cod), RhH(CO)(PPh.sub.3).sub.3, Rh(CO)(PPh.sub.3)(acac), and Rh-2-ethylhexanoate at a molar ratio of Pt/Rh in the range of 0.1 to 100.

2. The composition of claim 1, whereby the molar ratio of Pt/Rh is in the range of 0.3 to 5.

3. The composition of claim 1, wherein the composition has a pot life ranging from 2 minutes to 10 hours.

4. The composition of claim 1, whereby the at least one rhodium compound is selected from the group consisting of Rh.sub.2(CO).sub.4Cl.sub.2 and [Rh(cod)Cl].sub.2.

5. The composition of claim 1, wherein the composition is in the form of an organic solution comprising at least one organic solvent in addition to the at least one platinum compound and the at least one rhodium compound.

6. The composition of claim 5, wherein the at least one organic solvent is selected from the group consisting of solvents that are reactive in a hydrosilylation reaction and solvents that are non-reactive in a hydrosilylation reaction.

7. The composition of claim 5, wherein the at least one organic solvent is an araliphatic compound.

8. The composition of claim 1, further comprising at least one inhibitor.

9. The composition of claim 1, further comprising one or more additives other than inhibitors.

10. The composition of claim 1, further comprising at least one compound that is reactive in a hydrosilylation reaction, and is selected from the group consisting of low-molecular, oligomeric, and polymeric compounds.

11. The composition of claim 10, wherein the at least one compound that is reactive in a hydrosilylation reaction is selected from the group consisting of: one or more compounds with at least one HSi group, one or more compounds with at least one olefinic double bond, and one or more compounds with at least one HSi group and at least one olefinic double bond.

12. The composition of claim 11, wherein the at least one compound that is reactive in a hydrosilylation reaction is one or more compounds with at least one HSi group and one or more compounds with at least one olefinic double bond, and/or one or more compounds with at least one HSi group and at least one olefinic double bond.

13. The composition of claim 12, wherein a precious metal fraction originating from the at least one platinum compound and the at least one rhodium compound is 10 to 1,000 wt.-ppm, relative to the total composition that is capable of hydrosilylation.

14. The composition of claim 1, wherein a precious metal fraction originating from the at least one platinum compound and the at least one rhodium compound of 10 wt.-ppm to 45 wt.-%, relative to the total composition.

15. A multicomponent system for production of a composition according to claim 1, the system comprising a component (i) in the form of an organic solution comprising at least one organic solvent and the at least one platinum compound without the at least one rhodium compound, and a separate component (ii) in the form of an organic solution comprising at least one organic solvent and the at least one rhodium compound without the at least one platinum compound.

16. The system of claim 15, further comprising at least one further separate component that differs from components (i) and (ii).

17. The system of claim 16, further comprising a component (i′) in the form of an organic solution comprising at least one organic solvent, wherein the at least one platinum compound, and the at least one rhodium compound, and at least one further separate component that differs from component (i′).

18. A method for performing a hydrosilylation reaction, the method comprising reacting a composition according to claim 1 with one or more hydrosilylation reaction precursors.

19. The method of claim 18, wherein the hydrosilylation reaction is a chemical synthesis of a low-molecular silane compound or a polymer network-forming poly-addition.

20. The method of claim 19, wherein the poly-addition serves for formation of an impression, a sealing, an embedding, a grouting, an impregnation, an elastomer moulded part or a coating on a substrate, or consists of the production thereof.

Description

EXAMPLES OF THE INVENTION AND REFERENCE EXAMPLES

(1) Example 1: A total of 2.07 g of a mixture of Karstedt Concentrate from HERAEUS (platinum fraction 20 wt %) and Polymer VS 500 from EVONIK, the mixture having a platinum fraction of 0.52 wt %, were mixed with 0.548 g of a xylene-containing Rh(acac)(CO).sub.2 solution having a rhodium fraction of 0.52 wt % to produce a catalyst composition.

(2) A total of 0.06 g 1-ethinylcyclohexanol, 79.9 g Polymer VS 500 from EVONIK, and 10.1 g Crosslinker 180 from EVONIK where mixed to produce a mixture that is capable of hydrosilylation.

(3) A total of 1.38 g of the catalyst composition were mixed with 90 g of the mixture that is capable of hydrosilylation and had been preheated to 40° C.

(4) The catalysed mixture thus produced that is capable of hydrosilylation was tested by means of DSC for the presence of an exothermic peak. The DSC test was an analysis of a hydrosilylation reaction by means of dynamic heat flux differential scanning calorimetry (measuring instrument: DSC 200 F3 Maia, manufacturer: Netzsch Gerätebau GmbH) in closed aluminium crucibles according to DIN 11357-5:2014, 3.1, 9.2, 10.1 under argon (10 L/min) using a heating rate of 10 K/min in the range from 30° C. to 200° C. The temperature listed in Table 1 corresponds to the tip of the exothermic peak. The reproducibility of the measurement was 1-2° C.

(5) Moreover, the pot life of the mixture was determined by rotational viscosimetry (Brookfield DV2Textra, Spindle LVT 4) at 40° C. The pot life corresponds to the time by which the initial viscosity has doubled. Typically, the mixture hardened thereafter within a few minutes.

(6) Example 2: The procedure was analogous to Example 1 with the difference being that 1.06 g of the mixture comprising a platinum fraction of 0.52 wt % and 0.290 g of the xylene-containing Rh(acac)(CO).sub.2 solution were added separately to the mixture that is capable of hydrosilylation.

(7) Examples 3 to 29: The procedure used in Examples 3 to 29 was analogous to Example 1.

(8) The results of Examples 1 to 29 are shown in the table below. Examples 3, 4, 6 to 8, 21-24, and 29 are reference examples.

(9) TABLE-US-00001 Pt + Exo- Ex- Molar Rh thermic am- ratio con- In- peak ple Rh compound Pt/Rh tent *.sup.) hibitor **.sup.) at ° C. Pot life 1 Rh(acac)(CO).sub.2 2 80 60 mg E ./. 1 h 2 Rh(acac)(CO).sub.2 2 80 60 mg E ./. 1 h 3 ./. n.a. 80 60 mg M 83 57 min 4 ./. n.a. 80 60 mg E ./. 1 h 25 min 5 Rh(acac)(CO).sub.2 2 80 60 mg M 69 36 min 6 ./. n.a. 30 120 mg E 109  1 h 47 min 7 ./. n.a. 30 60 mg E 99 11 h 8 ./. n.a. 30 ./. ./. 20 min 9 [Rh(CO).sub.2Cl].sub.2 10.0 30 60 mg E 98 ./. 10 [Rh(CO).sub.2Cl].sub.2 1.3 30 60 mg E 93 3 h 17 min 11 [Rh(COD)Cl].sub.2 2 30 60 mg E 92 ./. 12 Rh(acac)(CO).sub.2 2.6 30 120 mg E 100   1 h 5 min 13 Rh(acac)(CO).sub.2 1.3 30 120 mg E 106  52 min 14 Rh(acac)(CO).sub.2 0.3 30 60 mg E 85  1 h 7 min 15 Rh(acac)(CO).sub.2 1.75 30 60 mg E 85 ./. 16 Rh(acac)(CO).sub.2 0 30 60 mg E ./. 1 h 17 Rh(acac)(CO).sub.2 2 30 ./. ./. 18 min 18 Rh-2- 5 30 60 mg E 96 ./. ethylhexanoate 19 Rh(acac)(CO).sub.2 2 100 60 mg E 80 1 h 20 Rh(acac)(CO).sub.2 2 100 400 mg E 104  ./. 21 ./. n.a. 100 60 mg E 81 1 h 25 min 22 ./. n.a. 100 400 mg E 106  ./. 23 ./. n.a. 150 120 mg E 86 ./. 24 ./. n.a. 150 200 mg A ./. 8 min 25 [Rh(COD)Cl].sub.2 2 150 200 mg A ./. 6 min 26 Rh(acac)(CO).sub.2 2 150 120 mg E 84 ./. 27 Rh(acac)(CO).sub.2 2 150 200 mg A ./. 5 min 28 [Rh(COD)Cl].sub.2 2.1 450 60 mg E ./. 5 min 29 ./. n.a. 450 60 mg E ./. 6 min n.a., not applicable A = Aniline E = 1-Ethinylcyclohexanol M = Maleic acid dimethylester *.sup.) Content of the mixture that is capable of hydrosilylation, in wt.-ppm **.sup.) per 90 g of mixture that is capable of hydrosilylation