Organosilicon copolymer composites, method of manufacture, and articles formed therefrom

1. An organosilicon composite, comprising:

30 to 90 vol. % of a cured organosilicon copolymer derived by curing an organosilicon polymer having, in the same copolymer, silicon-containing repeating units comprising a silicon hydride and silicon-containing repeating units comprising a C 1-10 ethylenically unsaturated group; and

10 to 70 vol. % of a dielectric filler having a hydrophobically-treated surface; wherein the treated filler has a hydrophobicity such that a time to sink in water of the composite is greater than 10 minutes at 23° C.; and/or wherein the composite has a water absorption of less than 0.2% over 24 hours at 23° C.

2. The organosilicon composite of claim 1 , having a UL94 flammability rating of V-0.

3. The organosilicon composite of claim 1 , having a dielectric loss of less than 0.005, measured over 1 to 10 GHz.

4. The organosilicon composite of claim 1 , derived from the crosslinking of a organosilicon of the formula

H—[SiH 2 CH 2 ] xn [SiH(R 1 )CH 2 ] yn [SiH(R 2 )CH 2 ] zn —H

wherein

R 1 is, independently at each occurrence, a C 1-6 alkyl, C 1-6 alkoxy, C 6-10 aryl, or C 1-6 aryloxy, each of which can be substituted with one or more fluorine atoms;

R 2 is, independently at each occurrence, a C 1-6 ethylenically unsaturated group capable of crosslinking with a silicon hydride group;

x+y+z=1 with the proviso that x, y, and z are not 0 or 1; and

n has a value from about 10 to about 140.

5. The organosilicon composite of claim 4 , wherein R 1 is methyl, phenyl, methoxy, ethoxy, or butoxy; and R 2 is allyl, propargyl, or ethynyl.

6. The organosilicon composite of claim 5 , where R 1 is methyl and R 2 is allyl.

7. The organosilicon composite of claim 1 , derived from the crosslinking of a organosilicon of the formula

—[Si(˜)(R)(C(˜)(H))] xn [SiR 1 R 2 CH 2 ] yn —

wherein:

R is, independently at each occurrence, a hydrogen, C 1-6 alkyl, C 1-6 alkoxy, C 6-10 aryl, or C 1-6 aryloxy, each of which can be substituted with one or more fluorine atoms;

R 1 and R 2 are, independently at each occurrence, a hydrogen, C 1-6 alkyl, C 1-6 alkoxy, C 6-10 aryl, C 1-6 aryloxy, or C 1-6 unsaturated group capable of crosslinking with a silicon hydride group;

at least of fraction of the R, R 1 , and R 2 is hydrogen, and at least a fraction of the R 1 , and R 2 groups is unsaturated;

n is the degree of polymerization of each unit in the polymer, and 0.1<x<0.8, 0.2≦y<0.9, and x+y=1; and

“˜” represents a polymer branch point, wherein one branch point is connected to the silicon atom and one to the carbon atom.

8. The organosilicon composite of claim 7 , wherein R is a hydrogen or methyl, and R 1 and R 2 are, independently at each occurrence, a hydrogen, methyl, phenyl, allyl, vinyl, or propargyl group.

9. The organosilicon composite of claim 1 , derived from the crosslinking of a organosilicon of the formula

—[SiHRC(˜)H] xn [SiR 1 R 2 CH 2 ] yn [SiR 3 R 4 CH 2 ] zn —

wherein

R is, independently at each occurrence, a hydrogen, C 1-6 alkyl, C 1-6 alkoxy, C 6-10 aryl, or C 1-6 aryloxy, each of which can be substituted with one or more fluorine atoms;

R 1 and R 2 are, independently at each occurrence, a hydrogen, C 1-6 alkyl, C 1-6 alkoxy, C 6-10 aryl, or C 1-6 aryloxy;

R 3 and R 4 , are, independently at each occurrence, a C 1-6 alkyl, C 1-6 alkoxy, C 6-10 aryl, C 1-6 aryloxy, or C 1-6 unsaturated group capable of crosslinking with a silicon hydride group;

at least of fraction of the R, R 1 , and R 2 groups is hydrogen, and at least a fraction of the R 3 and R 4 groups are unsaturated;

n is the degree of polymerization of each unit in the polymer, and 0.1<x<0.8, 0<y<0.8, 0.2<z<0.8 and x+y+z=1; and

“˜” represents a polymer branch point, wherein one branch point is connected to the silicon atom and one to the carbon atom.

10. The organosilicon composite of claim 9 , wherein R is a hydrogen or methyl, and R 1 and R 2 are, independently at each occurrence, a hydrogen, methyl, or phenyl, and R 3 and R 4 are, independently at each occurrence, a methyl, phenyl, vinyl, allyl, or propargyl group.

11. The organosilicon composite of claim 1 , derived from the crosslinking of a organosilicon of the formula

—[Si(H)(R)O] xn —[Si(R 1 )(R)O] yn —

wherein

R is, independently at each occurrence, a C 1-6 alkyl, C 1-6 alkoxy, C 6-10 aryl, or C 1-6 aryloxy, each of which can be substituted with one or more fluorine atoms;

R 1 is, independently at each occurrence, a C 1-10 group capable of crosslinking with a silicon hydride group; and

n is the degree of polymerization of each unit in the polymer, and x+y=1, with the proviso that x and y are not 1 or 0.

12. The organosilicon composite of claim 11 , wherein each R is methyl, R 1 is derived from a compound having at least two unsaturated carbon-carbon bonds, preferably dicyclopentadiene, isoprene, 4-vinyl-1-cyclohexene, and x is 0.6 to 0.9, and y is 0.1 to 0.4.

13. The organosilicon composite of claim 1 , derived from the crosslinking of a organosilicon of the formula

—[Si(Ph)(R′)O] xn —[Si(vinyl)(R″)O] yn [Si(H)(R′″)O] zn —

wherein

each R′, R″, and R′″ is independently hydrogen, methyl, vinyl, or phenyl;

n is 1 to 600, and

x+y+z=1, with the proviso that x, y, and z are not 1 or 0.

14. The organosilicon composite of claim 13 , wherein R′ is vinyl or methyl, R″ is hydrogen or methyl, R′″ is hydrogen or methyl, x=0.05 to 0.8, y=0.05 to 0.5, and z=0.05 to 0.8.

15. The organosilicon composite of claim 13 , wherein R′ is methyl, R″ is methyl, R′″ is methyl, and x=0.05 to 0.8, y=0.05 to 0.5, and z=0.05 to 0.8.

16. The organosilicon composite of claim 1 , derived from the crosslinking of a organosilicon of the formula

—[Si(Ph)(R′)O] xn —[Si(vinyl)(R″)O] yn [Si(H)(R′″)O] zn —

wherein

R′, R″, and R′″ is independently hydrogen, methyl, vinyl, or phenyl;

n is 1 to 600; and

x+y+z=1, with the proviso that none of x, y, and z is one, and one of x, y, or z is zero.

17. The organosilicon composite of claim 16 , wherein R′ is vinyl or methyl, R″ is hydrogen or methyl, R′″ is hydrogen or methyl, x=0 or 0.05 to 0.8, y=0 or 0.05 to 0.5, and z=0 or 0.05 to 0.8.

18. The organosilicon composite of claim 16 , wherein x is zero, and R″ and R′″ are methyl.

19. The organosilicon composite of claim 1 , wherein the filler is titanium dioxide, barium titanate, strontium titanate, silica, fused amorphous silica; corundum, wollastonite, aramide fibers, fiberglass, Ba 2 Ti 9 O 20 , glass spheres, quartz, boron nitride, aluminum nitride, silicon carbide, beryllia, alumina, magnesia, mica, talcs, nanoclays, aluminosilicates, magnesium hydroxide, or a combination comprising at least one of the foregoing fillers.

20. The organosilicon composite of claim 1 , wherein the hydrophobic treatment comprises a silane treatment or a hydride-substituted diorganosiloxane treatment.

21. A circuit subassembly comprising:

a layer of the organosilicon composite of claim 1 , the layer having a first side and a second side; and

a conductive layer disposed on the first side of the organosilicon composite layer.

22. The circuit subassembly of claim 21 , further comprising an adhesive layer disposed between the conductive layer and the organosilicon composite layer, wherein the adhesive layer comprises a poly(arylene ether).

23. A composition for the formation of the organosilicon composite of claim 1 , comprising:

30 to 90 vol. % of an organosilicon copolymer having silicon-containing repeating units comprising a silicon hydride and silicon-containing repeating units comprising a C 1-10 ethylenically unsaturated group; and

10 to 70 vol. % of a dielectric filler having a hydrophobically-treated surface.

24. A method for making an organosilicon composite, comprising curing a composition comprising

30 to 90 vol. % of an organosilicon copolymer having silicon-containing repeating units comprising a silicon hydride and silicon-containing repeating units comprising a C 1-10 ethylenically unsaturated group; and

10 to 70 vol. % of a dielectric filler having a hydrophobically-treated surface; wherein the treated filler has a hydrophobicity such that a time to sink of the composite in water is greater than 10 minutes at 23° C. and/or the composite has a water absorption of less than 0.2% over 24 hours at 23° C.