Curable organopolysiloxane composition and optical semiconductor device

1. A curable organopolysiloxane composition comprising at least the following components:

(A) an alkenyl-containing organopolysiloxane that comprises 40 to 70 wt. % of constituent (A-1) and 30 to 60 wt. % of constituent (A-2), wherein

constituent (A-1) comprises an organopolysiloxane of the following average compositional formula:

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

where R 1 designates phenyl groups, methyl groups, or alkenyl groups having 2 to 10 carbon atoms; 0.1 to 50 mole % of all R 1 groups are alkenyl groups having 2 to 10 carbon atoms; methyl groups constitute 90 mole % or more of the sum of methyl and phenyl groups contained in R 1 ; “a”, “b”, “c”, and “d” are numbers that satisfy the following conditions: 0≦a≦0.05; 0.9≦b≦1; 0≦c≦0.03; 0≦d≦0.03; and a+b+c+d=1;

constituent (A-2) comprises an organopolysiloxane of the following average compositional formula:

(R 2 3 SiO 1/2 ) e (R 2 2 SiO 2/2 ) f (R 2 SiO 3/2 ) g (SiO 4/2 ) h (HO 1/2 ) i

where R 2 designates phenyl groups, methyl groups, or alkenyl groups having 2 to 10 carbon atoms; 5 to 10 mole % of all R 2 groups are alkenyl groups having 2 to 10 carbon atoms; methyl groups constitute 90 mole % or more of the sum of methyl and phenyl groups contained in R 2 ; “e”, “f”, “g”, “h” and “i” are numbers that satisfy the following conditions: 0.4≦e≦0.6; 0≦f≦0.05; 0≦g≦0.05; 0.4≦h≦0.6; 0.01≦i≦0.05; and e+f+g+h=1;

(B) an organopolysiloxane that contains silicon-bonded hydrogen atom and comprises 10 to 50 wt. % of constituent (B-1), 50 to 90 wt. % of constituent (B-2), and 0 to 30 wt. % of constituent (B-3); in an amount that the silicon-bonded hydrogen atoms in component (B) are in the range of 0.5 to 2.0 moles per 1 mole of the total content of alkenyl groups in component (A), wherein

constituent (B-1) comprises an organopolysiloxane that contains at least 0.5 wt. % of silicon-bonded hydrogen atoms and that is represented by the following average molecular formula:

R 3 3 SiO(R 3 2 SiO) j (R 3 HSiO) k SiR 3 3

where R 3 designates phenyl groups or methyl groups; methyl groups constitute 90 mole % or more of all groups contained in R 3 ; “j” is a number in the range of 0 to 35; and “k” is a number in the range of 5 to 100;

constituent (B-2) comprises an organopolysiloxane that contains at least 0.5 wt. % of silicon-bonded hydrogen atoms and that is represented by the following average compositional formula:

(HR 4 2 SiO 1/2 ) l (R 4 3 SiO 1/2 ) m (R 4 2 SiO 2/2 ) n (R 4 SiO 3/2 ) o (SiO 4/2 ) p (R 5 O 1/2 ) q

where R 4 designates phenyl groups or methyl groups; methyl groups constitute 90 mole % or more of all groups contained in R 4 ; R 5 designates hydrogen atoms or alkyl groups having 1 to 10 carbon atoms; and “l”, “m”, “n”, “o”, “p” and “q” are numbers that satisfy the following conditions: 0.4≦l≦0.7; 0≦m≦0.2; 0≦n≦0.05; 0≦o≦0.5; 0.3≦p≦0.6; 0≦q≦0.05; and l+m+n+o+p=1;

constituent (B-3) is an organopolysiloxane represented by the following average molecular formula:

HR 6 2 SiO(R 6 2 SiO) r SiR 6 2 H

where R 6 represents phenyl or methyl groups; methyl groups constitute at least 90% of all groups contained in R 6 ; and “r” is a number in the range of 10 to 100; and

(C) a hydrosilylation-reaction catalyst, in an amount sufficient for curing the composition.

2. The curable organopolysiloxane composition of claim 1 , further comprising (D) fumed silica having BET specific area of 20 to 200 m 2 /g and added in an amount of 1 to 10 parts by weight per 100 parts by weight of the sum of components (A) to (C).

3. A cured body of the curable organopolysiloxane composition of claim 1 , wherein the cured body has a type A durometer hardness in the range of 70 to 90 according to JIS K 6253.

4. The curable organopolysiloxane composition of claim 1 , further comprising a sealant or a bonding agent for optical semiconductor elements.

5. The curable organopolysiloxane composition of claim 4 , wherein the optical semiconductor elements are light emitting diodes.

6. An optical semiconductor device, comprising at least one optical semiconductor element, wherein the at least one optical semiconductor element is sealed and/or bonded with a cured body of the curable organopolysiloxane composition of claim 1 .

7. The optical semiconductor device of claim 6 , wherein the at least one optical semiconductor element is a light emitting diode.

8. An optical semiconductor device, comprising a plurality of optical semiconductor elements, wherein each optical semiconductor element is sealed and/or bonded with a cured body of the curable organopolysiloxane composition of claim 1 .

9. The curable organopolysiloxane composition of claim 1 , wherein constituent (A-1) has a viscosity at 25° C. in the range of 3 to 1,000,000 mPa·s.

10. The curable organopolysiloxane composition of claim 1 , wherein component (A) has a viscosity at 25° C. in the range of 100 to 5,000,000 mPa·s.

11. The curable organopolysiloxane composition of claim 1 , wherein constituent (B-1) has a viscosity at 25° C. in the range of 3 to 10,000 mPa·s.

12. The curable organopolysiloxane composition of claim 1 , wherein component (B) has a viscosity at 25° C. in the range of 5 to 100,000 mPa·s.

13. The curable organopolysiloxane composition of claim 1 , wherein constituent (B-1) is an interfacial bonding improver.

14. The curable organopolysiloxane composition of claim 1 , further comprising a pot life extender in an amount of 0.0001 to 5 parts by weight of the sum of components (A), (B) and (C).

15. The curable organopolysiloxane composition of claim 1 , further comprising an adhesion promoter that does not contain active nitrogen atoms.

16. A curable organopolysiloxane composition comprising at least the following components:

(A) an alkenyl-containing organopolysiloxane that comprises constituent (A-1) and constituent (A-2), wherein

constituent (A-1) comprises an organopolysiloxane of the following average compositional formula:

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

where R 1 designates phenyl groups, methyl groups, or alkenyl groups having 2 to 10 carbon atoms; 0.1 to 50 mole % of all R 1 groups are alkenyl groups having 2 to 10 carbon atoms; methyl groups constitute 90 mole % or more of the sum of methyl and phenyl groups contained in R 1 ; “a”, “b”, “c”, and “d” are numbers that satisfy the following conditions: 0≦a≦0.05; 0.9≦b≦1; 0≦c≦0.03; 0≦d≦0.03; and a+b+c+d=1;

constituent (A-2) comprises an organopolysiloxane of the following average compositional formula:

(R 2 3 SiO 1/2 ) e (R 2 2 SiO 2/2 ) f (R 2 SiO 3/2 ) g (SiO 4/2 ) h (HO 1/2 ) i

where R 2 designates phenyl groups, methyl groups, or alkenyl groups having 2 to 10 carbon atoms; 5 to 10 mole % of all R 2 groups are alkenyl groups having 2 to 10 carbon atoms; methyl groups constitute 90 mole % or more of the sum of methyl and phenyl groups contained in R 2 ; “e”, “f”, “g”, “h” and “i” are numbers that satisfy the following conditions: 0.4≦e≦0.6; 0≦f≦0.05; 0≦g≦0.05; 0.4≦h≦0.6; 0.01≦i≦0.05; and e+f+g+h=1;

(B) an organopolysiloxane that contains silicon-bonded hydrogen atom and comprises constituent (B-1) and constituent (B-2; in an amount that the silicon-bonded hydrogen atoms in component (B) are in the range of 0.5 to 2.0 moles per 1 mole of the total content of alkenyl groups in component (A), wherein

constituent (B-1) comprises an organopolysiloxane that contains at least 0.5 wt. % of silicon-bonded hydrogen atoms and that is represented by the following average molecular formula:

R 3 3 SiO(R 3 2 SiO) j (R 3 HSiO) k SiR 3 3

where R 3 designates phenyl groups or methyl groups; methyl groups constitute 90 mole % or more of all groups contained in R 3 ; “j” is a number in the range of 0 to 35; and “k” is a number in the range of 5 to 100;

constituent (B-2) comprises an organopolysiloxane that contains at least 0.5 wt. % of silicon-bonded hydrogen atoms and that is represented by the following average compositional formula:

(HR 4 2 SiO 1/2 ) l (R 4 3 SiO 1/2 ) m (R 4 2 SiO 2/2 ) n (R 4 SiO 3/2 ) o (SiO 4/2 ) p (R 5 O 1/2 ) q

where R 4 designates phenyl groups or methyl groups; methyl groups constitute 90 mole % or more of all groups contained in R 4 ; R 5 designates hydrogen atoms or alkyl groups having 1 to 10 carbon atoms; and “l”, “m”, “n”, “o”, “p” and “q” are numbers that satisfy the following conditions: 0.4≦l≦0.7; 0≦m≦0.2; 0≦n≦0.05; 0≦o≦0.5; 0.3≦p≦0.6; 0≦q—0.05; and l+m+n+o+p=1; and

(C) a hydrosilylation-reaction catalyst, in an amount sufficient for curing the composition.

17. A curable organopolysiloxane composition of claim 16 , wherein component (A) comprises 45 to 65 wt. % of constituent (A-1) and 35 to 55 wt. % of constituent (A-2).

18. A curable organopolysiloxane composition of claim 16 , wherein component (B) comprises 15 to 35 wt. % of constituent (B-1) and 65 to 85 wt. % of constituent (B-2).