Curable organopolysiloxane composition and method for manufacturing the same

1. A curable organopolysiloxane composition comprising:

(A) an organopolysiloxane having at least two silicon-bonded alkenyl groups and having an average unit formula (I):

(R 1 2 SiO 2/2 ) a (R 2 3 SiO 1/2 ) b (R 3 SiO 3/2 ) c (SiO 4/2 ) d (CH 2 CH 2 ) e   (I);

wherein R 1 , R 2 and R 3 are independently a substituted or unsubstituted mono-valent hydrocarbon group, each of R 1 is the same with or different from each other, each of R 2 is the same with or different from each other, and a>0, b>0, c≧0, d≧0, and e>0, wherein c+d>0;

(B) a branched organopolysiloxane having at least one silicon-bonded alkenyl group and having a siloxane unit of formula R 4 SiO 3/2 wherein R 4 is a substituted or unsubstituted mono-valent hydrocarbon group, and wherein the amount of component (B) is about 1 part by weight to about 9900 parts by weight, based on 100 parts by weight of component (A);

(C) an organopolysiloxane having an average unit formula (II) being capped with H:

(R 5 2 SiO 2/2 ) f (R 6 3 SiO 1/2 ) g (R 7 SiO 3/2 ) h (SiO 4/2 ) i (CH 2 CH 2 ) j   (II):

wherein R 5 , R 6 and R 7 are independently H or a substituted or unsubstituted mono-valent hydrocarbon group, wherein each of R 5 is the same with or different from each other, each of R 6 is the same with or different from each other, f>0, g>0, h≧0, i≧0, j≧0, and the amount of component (C) is about 1 parts by weight to about 300 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B); and

(D) a catalyst.

2. The curable organopolysiloxane composition of claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently an alkyl or aryl group.

3. The curable organopolysiloxane composition of claim 1 , wherein about 0.1 percent by mole to about 40 percent by mole of R 1 , R 2 and R 3 are alkenyl groups, and at least about 10 percent by mole of R 1 , R 2 and R 3 are aryl groups, based on the total amount of R 1 , R 2 and R 3 .

4. The curable organopolysiloxane composition of claim 1 , wherein:

a is an integer ranging from about 1 to about 200;

b is an integer ranging from about 1 to about 200;

c is an integer ranging from 0 to about 10;

d is an integer ranging from 0 to about 5; and

e is an integer ranging from about 1 to about 100, wherein c+d>0.

5. The curable organopolysiloxane composition of claim 1 , wherein component (A) is prepared by an addition reaction of a siloxane having at least two alkenyl groups and a siloxane having at least two H.

6. The curable organopolysiloxane composition of claim 5 , wherein:

the siloxane having at least two alkenyl groups has an average unit formula (III):

(R 1′ 2 SiO 2/2 ) a′ (R 2′ 3 SiO 1/2 ) b′ (R 3′ SiO 3/2 ) c′ (SiO 4/2 ) d′   (III);

and

the siloxane having at least two H has an average unit formula (IV):

(R 5′ 2 SiO 2/2 ) f′ (R 6′ 3 SiO 1/2 ) g′ (R 7′ SiO 3/2 ) h′ (SiO 4/2 ) i′   (IV),

wherein R 1′ , R 2′ , R 3′ , R 4′ , R 5′ , R 6′ and R 7′ are independently a substituted or unsubstituted mono-valent hydrocarbon group, each of R 1′ is the same with or different from each other, each of R 2′ is the same with or different from each other, each of R 5′ is the same with or different from each other, and each of R 6′ is the same with or different from each other, and a′>0, b′>0, c′≧0, d′≧0, f′>0, g′>0, h′≧0 and i′≧0.

7. The curable organopolysiloxane composition of claim 1 , wherein component (B) has at least one silicon-bonded alkenyl group and at least one silicon-bonded aryl group.

8. The curable organopolysiloxane composition of claim 1 , wherein about 0.1 percent by mole to about 40 percent by mole of R 4 are alkenyl groups, and about at least 10 percent by mole of R 4 are aryl groups, based on the total amount of R 4 .

9. The curable organopolysiloxane composition of claim 1 , wherein component (B) has an average unit formula (V):

(R 4 SiO 3/2 ) k [(CH 2 ═CH)(R 8 ) 2 SiO 1/2 ] 1-k   (V),

wherein R 4 is as defined in claim 1 , R 8 is independently a substituted or unsubstituted mono-valent hydrocarbon group, each of R 8 is the same with or different from each other, and k ranges from about 0.5 to about 0.95.

10. The curable organopolysiloxane composition of claim 9 , wherein R 4 is a aryl group, R 8 is independently an alkyl group with 1 to 8 carbon atoms and k ranges from about 0.6 to about 0.9.

11. The curable organopolysiloxane composition of claim 1 , wherein the amount of component (B) is about 200 parts by weight to about 3000 parts by weight, based on 100 parts by weight of component (A).

12. The curable organopolysiloxane composition of claim 11 , wherein the amount of component (B) is about 300 parts by weight to about 2500 parts by weight, based on 100 parts by weight of component (A).

13. The curable organopolysiloxane composition of claim 1 , wherein about 0.1 percent by mole to about 50 percent by mole of R 5 , R 6 and R 7 are H, and at least about 10 percent by mole of R 5 , R 6 and R 7 are aryl groups, based on the total amount of R 5 , R 6 and R 7 .

14. The curable organopolysiloxane composition of claim 1 , wherein:

f is an integer ranging from about 1 to about 50;

g is an integer ranging from about 1 to about 50;

h is an integer ranging from 0 to about 10;

i is an integer ranging from 0 to about 5; and

j is an integer ranging from 0 to about 30.

15. The curable organopolysiloxane composition of claim 1 , wherein the amount of component (C) is about 10 parts by weight to about 250 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B).

16. The curable organopolysiloxane composition of claim 15 , wherein the amount of component (C) is about 15 parts by weight to about 200 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B).

17. The curable organopolysiloxane composition of claim 1 , wherein the catalyst of component (D) is selected from the following group: Pt, Rh, Pd, compounds and complexes of the above, and combinations thereof.

18. The curable organopolysiloxane composition of claim 1 for use as a packaging material for light emitting diodes.

19. The curable organopolysiloxane composition of claim 5 for use as a packaging material for light emitting diodes.