ONE-COMPONENT, CURABLE SILICONE COMPOSITION THAT IS STABLE IN STORAGE

Abstract

The invention relates to a composition containing a) 30 to 99.799989 wt % of at least one linear or branched polyorganosiloxane, containing at least two alkenyl or alkinyl groups, as component A; b) 0.1 to 30 wt % of at least one linear or branched polyorganosiloxane containing at least 3 Si—H groups, as component B; c) 0.000001 to 1 wt % of a hydrosilylation catalyst chosen from the group comprising the platinum-1, 3-divinyl-1,1, 3, 3-tetramethyl disiloxane complex (Karstedt complex), the platinum-1,3-diallyl-1,1,3,3-tetramethyldisiloxane complex, the platinum-1,3-divinyl-1,3-dimethyl-1,3-diphenyldisiloxane complex, the platinum-1,1,3,3-tetraphenyl-disiloxane complex, and the platinum-1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane complex, as component C; d) 0.00001 to 5 wt % of tris(2,4-di-tert.-butylphenyl) phosphite, as component D; e) 0 to 69.899989 wt % of at least one possibly coated filler as component E; f) 0 to 69.899989 wt % of one or more linear or branched polyorganosiloxanes, containing two terminal Si—H groups or one terminal Si—H group and one terminal alkenyl group, as component F; g) 0 to 69.799989 wt % of one or more further linear or branched polyorganosiloxanes as component G; h) 0 to 10 wt % of one or more additives as component H; wherein the sum of the components A to H yields 100 wt %.

Claims

1. A composition comprising a) from 30 to 99.799989% by weight of at least one linear or branched polyorganosiloxane comprising at least two alkenyl or alkynyl groups, as component A; b) from 0.1 to 30% by weight of at least one linear or branched polyorganosiloxane comprising at least 3 Si—H groups, as component B; c) from 0.000001 to 1% by weight of a hydrosilylation catalyst selected from the group consisting of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (Karstedt complex), a platinum-1,3-diallyl-1,1,3,3-tetramethyldisiloxane complex, a platinum-1,3-divinyl-1,3-dimethyl-1,3-diphenyldisiloxane complex, a platinum-1,1,3,3-tetraphenyldisiloxane complex, and a platinum-1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane complex, as component C; d) from 0.00001 to 5% by weight of tris(2,4-di-tert-butylphenyl) phosphite as component D; e) from 0 to 69.899989% by weight of at least one optionally coated filler as component E; f) from 0 to 69.899989% by weight of one or more linear or branched poly-organosiloxanes comprising two terminal Si—H groups or one terminal Si—H group and one terminal alkenyl group, as component F; g) from 0 to 69.799989% by weight of one or more other linear or branched polyorganosiloxanes as component G; h) from 0 to 10% by weight of one or more additives as component H; where the entirety of components A to H gives 100% by weight.

2. The composition according to claim 1, characterized in that the hydrosilylation catalyst is the platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (Karstedt complex).

3. The composition according to claim 1, characterized in that the composition comprises, as component A, at least one linear polyorganosiloxane of the general formula (IV) ##STR00006## where R.sup.8 is selected independently from C.sub.1-C.sub.6-alkyl; and n is a number from 6 to 1000.

4. The composition according to claim 1, characterized in that the composition comprises, as component B, at least one linear polydimethylsiloxane comprising at least 3 Si—H groups, where the Si—H content of the polydimethylsiloxane is from 4 to 8 mmol/g.

5. The composition according to claim 1, characterized in that component F is one or more polyorganosiloxanes of the general formula (II) ##STR00007## where R.sup.4 is selected independently from C.sub.1-C.sub.6-alkyl; R.sup.5 is selected from H and C.sub.2-C.sub.6-alkenyl; and m is a number from 1 to 400.

6. The composition according to claim 1, characterized in that component G is one or more polyorganosiloxanes of the general formula (III) ##STR00008## where R.sup.6 is selected independently from C.sub.1-C.sub.6-alkyl; R.sup.7 is selected independently from C.sub.1-C.sub.6-alkyl; and p is a number from 1 to 2000.

7. A process for the application of a protective coating onto an electrical or electronic component or device, comprising: a) providing a composition according to claim 1; b) applying the composition onto an electrical or electronic component or device; and c) curing the applied composition via heating, thus forming the protective coating.

8. (canceled)

9. An electrical or electronic component or device with, applied thereon, a protective coating, obtained via the process according to claim 7.

Description

EXAMPLES

[0183] All parts data are parts by weight. A Speedmixer DAC 150.1 from Hauschild was used to mix the components. A TYP MCR 102 rheometer from Anton Paar was used for viscosity measurement at 25° C. Shore A hardness was measured with a commercially available Shore A measurement device. Penetration hardness was measured with a Petrotest PNR10 device.

Example 1

[0184] 290 parts of ground quartz, 10 parts of ground dolomite, 20 parts of a coated fumed silica, 630 parts of vinyl-terminated polydimethylsiloxane with viscosity 500 mPa.Math.s and vinyl content 0.15 mmol/g, 30 parts of polyhydropolydimethylsiloxane with Si—H content 7 mmol/g, 2.5 parts of methacryloxypropyltrimethoxysilane and 2.5 parts of 3-glycidoxypropyltrimethoxysilane are mixed at 3500 revolutions for 2 minutes. This increased the temperature of the mixture. After cooling, 0.5 part of a 20% solution of tris(2,4-di-tert-butylphenyl) phosphite in xylene was added and the mixture was mixed at 3500 revolutions for 15 seconds. 0.6 part of a 1% solution of Karstedt complex in 1,3-divinyltetramethyldisiloxane was then added and the mixture was mixed at 3500 revolutions for 15 seconds.

[0185] The mixture was then stored for 6 months at room temperature. No significant viscosity rise was observed. Hardening is successful in 10 minutes at 120° C. The highest Shore A hardness is reached after 30 minutes at the said temperature.

Example 2

[0186] 430 parts of ground quartz, 4 parts of a fumed silica, 40 parts of ground calcium carbonate, 500 parts of vinyl-terminated polydimethylsiloxane with viscosity 200 mPa.Math.s and vinyl content 0.25 mmol/g and 25 parts of polyhydropolydimethyl-siloxane with Si—H content 4 mmol/g are mixed at 3500 revolutions for 2 minutes. This increased the temperature of the mixture. After cooling, 0.5 part of a 20% solution of tris(2,4-di-tert-butylphenyl) phosphite in xylene was added and the mixture was mixed at 3500 revolutions for 15 seconds. 0.5 part of a 1% solution of Karstedt complex in 1,3-divinyltetramethyldisiloxane was then added and the mixture was mixed at 3500 revolutions for 15 seconds.

[0187] The mixture was then stored for 6 months at room temperature. No significant viscosity rise was observed. Hardening is successful in 10 minutes at 120° C. The highest Shore A hardness is reached after 30 minutes at the said temperature.

Example 3

[0188] 883 parts of vinyl-terminated polydimethylsiloxane with viscosity 800 mPa.Math.s and vinyl content 0.20 mmol/g, 13 parts of polyhydropolydimethylsiloxane with Si—H content 7 mmol/g, 100 parts of a dihydropolydimethylsiloxane, 2.5 parts of methacryloxypropyltrimethoxysilane and 2.5 parts of 3-glycidoxypropyltrimethoxy-silane are mixed at 3500 revolutions for 2 minutes. This increased the temperature of the mixture. After cooling, 0.5 part of a 20% solution of tris(2,4-di-tert-butylphenyl) phosphite in xylene was added and the mixture was mixed at 3500 revolutions for 15 seconds. 0.5 part of a 1% solution of Karstedt complex in 1,3-divinyltetramethyldisiloxane was then added and the mixture was mixed at 3500 revolutions for 15 seconds.

[0189] The mixture was then stored for 6 months at room temperature. No significant viscosity rise was observed. Hardening is successful in 10 minutes at 120° C. The highest Shore A hardness is reached after 30 minutes at the said temperature.

Example 4

[0190] 966 parts of vinyl-terminated polydimethylsiloxane with viscosity 1000 mPa.Math.s and vinyl content 0.12 mmol/g, 30 parts of polyhydropolydimethylsiloxane with Si—H content 0.9 mmol/g and 6 parts of polyhydropolydimethylsiloxane with Si—H content 4 mmol/g are mixed at 3500 revolutions for 2 minutes. This increased the temperature of the mixture. After cooling, 0.5 part of a 20% solution of tris(2,4-di-tert-butylphenyl) phosphite in xylene was added and the mixture was mixed at 3500 revolutions for 15 seconds. 0.5 part of a 1% solution of Karstedt complex in 1,3-divinyltetramethyldisiloxane was then added and the mixture was mixed at 3500 revolutions for 15 seconds.

[0191] The mixture was then stored for 6 months at room temperature. No significant viscosity rise was observed. Hardening is successful in 10 minutes at 120° C. The highest PEN hardness is reached after 30 minutes at the said temperature.