Curable composition and method for manufacturing the same

1. A curable composition comprising:

(A) a branched polymer having an average unit formula (I′):

[(R″) 2 SiO 2/2 ] a″ [(CH 2 ═CH)(R″) 2 SiO 1/2 ] b″ [R″SiO 3/2 ] c″ [O 1/2 Si(R″) 2 (CH 2 CH 2 )(R″) 2 SiO 1/2 ] e″   (I′),

wherein

R″ is a substituted or unsubstituted mono-valent hydrocarbon group, each of R″ is the same with or different from each other,

a″ is an integer ranging from 0 to 200,

b″ is an integer ranging from 3 to 6,

c″ is an integer ranging from 1 to 4, and

e″ is an integer ranging from 2 to 200;

(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 composition of claim 1 , wherein R″ is C 1 -C 3 alkyl or aryl group.

3. The curable composition of claim 2 , wherein R″ is methyl or phenyl.

4. The curable composition of claim 1 , wherein the component (A) is selected from:

and

a combination thereof,

wherein

the repeated units, X, T, X′ and T′ are distributed in a random manner or in an alternative manner;

X is

X′ is

T is

T′ is

R″ is defined in claim 1 ;

p is an integer ranging from 1 to 4 and each of p is the same with or different from each other;

q is an integer ranging from 1 to 4 and each of q is the same with or different from each other;

r is an integer ranging from 1 to 3; and

t is an integer ranging from 0 to 50 and each of t is the same with or different from each other.

5. The curable composition of claim 4 , wherein about at least 10 percent by mole of R″ are aryl groups, based on the total amount of R″.

6. The curable composition of claim 4 , wherein r is 1.

7. The curable composition of claim 6 , wherein the component (A) has the following formula:

wherein X, T, R″, p and q are as defined in claim 4 , t 1 and t 2 are independently an integer ranging from 0 to 30 and t 1 +t 2 ranges from 0 to 50.

8. The curable composition of claim 7 for use as a packaging material for light emitting diodes.

9. The curable composition of claim 4 for use as a packaging material for light emitting diodes.

10. The curable composition of claim 1 , wherein component (A) is prepared by an addition reaction.

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

12. The curable composition of claim 1 , wherein about at least 10 percent by mole of R 4 are aryl groups, based on the total amount of R 4 .

13. The curable 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 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.

14. The curable composition of claim 13 , wherein R 4 is an aryl group or C 1 -C 3 alkyl, and R 8 is an aryl group or C 1 -C 8 alkyl.

15. The curable composition of claim 1 , wherein component (B) has an average unit formula (VI):

(R 4 SiO 3/2 ) x (SiO 4/2 ) y [(R 9 ) 3 SiO 1/2 ] 1-x-y   (VI),

wherein R 4 is as defined in claim 1 , R 9 is a substituted or unsubstituted mono-valent hydrocarbon group selected from aryl, C 1 -C 8 alkyl and C 2 -C 8 alkenyl, each of R 9 is the same with or different from each other, x>0, y>0, and x+y ranges from about 0.35 to about 0.85 and wherein about 0.1 percent to about 40 percent by mole of R 9 is C 2 -C 8 alkenyl.

16. The curable composition of claim 15 , wherein R 4 is an aryl group or C 1 -C 3 alkyl.

17. The curable 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).

18. The curable composition of claim 17 , 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).

19. The curable 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 .

20. The curable 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.

21. The curable 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).

22. The curable composition of claim 21 , 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).

23. The curable 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.

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

25. A semiconductor device, in which semiconductor elements are coated with a cured product of the curable composition according to claim 1 .

26. The semiconductor device according to claim 25 , wherein the semiconductor elements are light emitting diodes or light sensors.