Aryl group-containing siloxane compositions including alkaline earth metal

1. An aryl group-containing siloxane composition comprising the reaction product of:

(A) an organopolysiloxane having at least two alkenyl groups per molecule;

(B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule; and

(C) a heat stabilizing composition comprising an alkaline earth metal;

in the presence of (D) a hydrosilylation catalyst;

wherein at least one of the ingredients (A) or (B) includes at least one aryl group, and

wherein the heat stabilizing composition comprises the reaction product of:

(i) an alkaline earth metal hydroxide or alkaline earth metal hydroxide hydrate comprising the formula: M(OH) 2 .pH 2 O, wherein M represents the alkaline earth metal and p ranges from 0 to 8; and

(ii) at least one silicon-containing compound having functional groups reactive with component (i);

wherein the alkaline earth metal M is present in an amount ranging from 0.1 to 25 weight percent of the total weight of the heat stabilizing composition.

2. The siloxane composition of claim 1 , wherein the at least one silicon-containing compound is selected from a silanol-functional siloxane, a silanol-functional silane, an alkoxy-functional silane, an alkoxy-functional siloxane, or any combination thereof.

3. The siloxane composition of claim 1 , wherein the at least one silicon-containing compound is selected from a chloro-functional siloxane, a chloro-functional silane, or any combination thereof.

4. An aryl group-containing siloxane composition comprising the reaction product of:

(A) an organopolysiloxane having at least two alkenyl groups per molecule;

(B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule; and

(C) a heat stabilizing composition comprising an alkaline earth metal;

in the presence of (D) a hydrosilylation catalyst;

wherein at least one of the ingredients (A) or (B) includes at least one aryl group, and wherein the heat stabilizing composition comprises the reaction product of:

(i) an alkaline earth metal oxide; and

(ii) at least one chloro-functional silicon-containing compound comprising a chloro-functional silane or a chloro-functional siloxane or a combination thereof.

5. An aryl group-containing siloxane composition comprising the reaction product of:

(A1) an alkaline earth metal-containing organopolysiloxane comprising M, D, T and/or Q units and having at least two alkenyl groups per molecule, wherein the at least two alkenyl groups are attached only via the M units and/or via the D units;

(B1) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule;

in the presence of (C1) a hydrosilylation catalyst;

wherein at least one of components (A1) or (B1) includes at least one aryl group.

6. The siloxane composition of claim 5 , wherein at least 20 mole % of the at least two alkenyl groups are attached via the M units and the remainder of the at least two alkenyl groups are attached via the D units.

7. The siloxane composition of claim 5 , wherein component (A1) comprises the reaction product of:

(i) an alkaline earth metal hydroxide or alkaline earth metal hydroxide hydrate comprising the formula: M(OH) 2 .pH2O, wherein M represents an alkaline earth metal and p ranges from 0 to 8; and

(ii) at least one silicon-containing compound according to the formula:

R 11 n (X 2 ) y SiO ((4-n-y/2) ;

wherein

the subscript n ranges from 0.8 to 2.2;

the subscript y ranges from 0.01 to 3;

each X 2 individually represents a hydrolysable group;

each R 11 individually represents hydrogen atoms or univalent hydrocarbon groups free of aliphatic unsaturated carbon-carbon bonds or univalent hydrocarbon groups having aliphatic unsaturated carbon-carbon bonds, with the proviso that any R 11 comprising an aliphatic unsaturated carbon-carbon bonds is attached via an M unit and/or via a D unit.

8. The siloxane composition of claim 5 , wherein component (A1) comprises the reaction product of:

(i) an alkaline earth metal oxide; and

(ii) at least one silicon-containing compound according to the formula:

R 11 n (X 2 ) y SiO ((4-n-y/2) ;

wherein

the subscript n ranges from 0.8 to 2.2;

the subscript y ranges from 0.01 to 3;

each X 2 individually represents a hydrolysable group and wherein at least one X 2 comprises Cl;

each R 11 individually represents hydrogen atoms or univalent hydrocarbon groups free of aliphatic unsaturated carbon-carbon bonds or univalent hydrocarbon groups having aliphatic unsaturated carbon-carbon bonds, with the proviso that any R 11 comprising an aliphatic unsaturated carbon-carbon bonds is attached via an M unit and/or via a D unit.

9. The siloxane composition according to claim 1 having a SiH/Vi molar ratio from 1:1 to 3:1.

10. A method for forming an aryl group-containing siloxane composition, the method comprising:

co-reacting the heat stabilizing composition of claim 1 with (A) an organopolysiloxane having at least two alkenyl groups per molecule and (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule in the presence of a hydrosilylation catalyst, wherein at least one of components (A) or (B) includes at least one aryl group.

11. A method for forming an aryl group-containing siloxane composition, the method comprising:

(a) forming an alkaline earth metal-containing organopolysiloxane comprising an alkaline earth metal and comprising M, D, T and/or Q units and having at least two alkenyl groups per molecule, wherein the at least two alkenyl groups are attached only via the M units and/or via the D units; and

(b) reacting component (a) with (i) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule in the presence of (ii) a hydrosilylation catalyst,

wherein at least one of components (a) or (i) includes at least one aryl group.

12. A light emitting device comprising an encapsulating layer comprising the aryl group-containing siloxane composition of claim 1 .

13. A light emitting device comprising an encapsulating layer comprising the aryl group-containing siloxane composition of claim 5 .

14. A method for forming an aryl group-containing siloxane composition, the method comprising:

co-reacting the heat stabilizing composition of claim 2 with (A) an organopolysiloxane having at least two alkenyl groups per molecule and (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule in the presence of a hydrosilylation catalyst, wherein at least one of components (A) or (B) includes at least one aryl group.

15. A method for forming an aryl group-containing siloxane composition, the method comprising:

co-reacting the heat stabilizing composition of claim 3 with (A) an organopolysiloxane having at least two alkenyl groups per molecule and (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule in the presence of a hydrosilylation catalyst, wherein at least one of components (A) or (B) includes at least one aryl group.

16. A method for forming an aryl group-containing siloxane composition, the method comprising:

co-reacting the heat stabilizing composition of claim 4 with (A) an organopolysiloxane having at least two alkenyl groups per molecule and (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule in the presence of a hydrosilylation catalyst, wherein at least one of components (A) or (B) includes at least one aryl group.

17. The siloxane composition according to claim 5 having a SiH/Vi molar ratio from 1:1 to 3:1.

18. A light emitting device comprising an encapsulating layer comprising the aryl group-containing siloxane composition of claim 4 .