Silicone gel composition and use thereof

1. A light-emitting semiconductor device having a light-emitting semiconductor element encapsulated by a silicone gel-cured material, wherein the silicone gel-cured material is produced by curing a silicone gel composition, is substantially transparent, and has 10 to 120 of direct reading value of ¼ consistency defined by JIS K 2220, and wherein the silicone gel composition comprises:

(A) branched organopolysiloxane in an amount of 100 parts by mass, having, on average, at least two alkenyl groups bonded to silicon atoms in a molecule, and a viscosity ranging from 10 to 10,000 mPa·s at 25° C.;

(B) organohydrogenpolysiloxane in an amount so that an amount of hydrogen atoms bonded to silicon atoms is 0.7 to 1.2 per one alkenyl group bonded to silicon atom in a total amount of the silicone gel composition, having at least two hydrogen atoms bonded to silicon atoms in a molecule, and a viscosity ranging from 2 to 1,000 mPa·s at 25° C.;

(C) a platinum-based addition reaction catalyst in an amount so that an amount of platinum-based metal is from 0.01 to 1,000 ppm in the total amount of the silicone gel composition; and

(D) a reaction product, in an amount of 0.2 to 10.0 parts by mass, of (d1) alkali metal silanolate with (d2) at least one ceric salt selected from cerium chloride and a carboxylic acid salt of cerium.

2. The light-emitting semiconductor device according to claim 1 , wherein the silicone gel composition further comprises (A2) linear organopolysiloxane, in an amount of 2 to 150 parts by mass per 100 parts by mass of the component (A), having at least two alkenyl groups bonded to silicon atoms in a molecule, and a viscosity ranging from 1.0 to 10,000 mPa·s at 25° C.

3. The light-emitting semiconductor device according to claim 1 , wherein, among total siloxane units constituting the branched organopolysiloxane (A) molecule, from 80.0 to 99.8 mol % of the units are R 2 SiO 2/2 units, from 0.1 to 10.0 mol % of the units are RSiO 3/2 units, and from 0.1 to 10.0 mol % of the units are R 3 SiO 1/2 units, wherein all the R groups represent monovalent hydrocarbon groups bonded to a silicon atom.

4. The light-emitting semiconductor device according to claim 3 , wherein, in the total monovalent hydrocarbon groups bonded to the silicon atoms in the branched organopolysiloxane (A), from 0.25 to 4.00 mol % are alkenyl groups.

5. The light-emitting semiconductor device according to claim 1 , wherein the component (D) comprises from 0.5 to 5.0 mass % of cerium metal.

6. The light-emitting semiconductor device according to claim 1 , wherein the component (d1) is an alkali metal silanolate compound obtained by subjecting (d1-1) at least one cyclic organopolysiloxane to a ring opening reaction using (d1-2) an alkali metal hydroxide, and then subjecting the resulting product to a further reaction with (d1-3) organopolysiloxane having a viscosity ranging from 10 to 10,000 mPa·s at 25° C.

7. The light-emitting semiconductor device according to claim 1 , wherein the compounded amount of the component (D) is such that a content of cerium metals in the component (D) is from 0.005 to 0.15 mass % based on the total amount of the composition.

8. The light-emitting semiconductor device according to claim 1 , wherein the silicone gel-cured material is substantially transparent and has 30 to 100 of direct reading value of ¼ consistency defined by JIS K 2220.

9. A general lighting device, optical substrate, or photoelectric substrate having a silicone gel-cured material, wherein the silicone gel-cured material is produced by curing a silicone gel composition, is substantially transparent, and has 10 to 120 of direct reading value of ¼ consistency defined by JIS K 2220, and wherein the silicone gel composition comprises:

(A) branched organopolysiloxane in an amount of 100 parts by mass, having, on average, at least two alkenyl groups bonded to silicon atoms in a molecule, and a viscosity ranging from 10 to 10,000 mPa·s at 25° C.;

(B) organohydrogenpolysiloxane in an amount so that an amount of hydrogen atoms bonded to silicon atoms is 0.7 to 1.2 per one alkenyl group bonded to silicon atom in a total amount of the silicone gel composition, having at least two hydrogen atoms bonded to silicon atoms in a molecule, and a viscosity ranging from 2 to 1,000 mPa·s at 25° C.;

(C) a platinum-based addition reaction catalyst in an amount so that an amount of platinum-based metal is from 0.01 to 1,000 ppm in the total amount of the silicone gel composition; and

(D) a reaction product, in an amount of 0.2 to 10.0 parts by mass, of (d1) alkali metal silanolate with (d2) at least one ceric salt selected from cerium chloride and a carboxylic acid salt of cerium.

10. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , wherein the silicone gel composition further comprises (A2) linear organopolysiloxane, in an amount of 2 to 150 parts by mass per 100 parts by mass of the component (A), having at least two alkenyl groups bonded to silicon atoms in a molecule, and a viscosity ranging from 1.0 to 10,000 mPa·s at 25° C.

11. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , wherein, among total siloxane units constituting the branched organopolysiloxane (A) molecule, from 80.0 to 99.8 mol % of the units are R 2 SiO 2/2 units, from 0.1 to 10.0 mol % of the units are RSiO 3/2 units, and from 0.1 to 10.0 mol % of the units are R 3 SiO 1/2 units, wherein all the R groups represent monovalent hydrocarbon groups bonded to a silicon atom.

12. The general lighting device, optical substrate, or photoelectric substrate according to claim 11 , wherein, in the total monovalent hydrocarbon groups bonded to the silicon atoms in the branched organopolysiloxane (A), from 0.25 to 4.00 mol % are alkenyl groups.

13. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , wherein the component (D) comprises from 0.5 to 5.0 mass % of cerium metal.

14. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , wherein the component (d1) is an alkali metal silanolate compound obtained by subjecting (d1-1) at least one cyclic organopolysiloxane to a ring opening reaction using (d1-2) an alkali metal hydroxide, and then subjecting the resulting product to a further reaction with (d1-3) organopolysiloxane having a viscosity ranging from 10 to 10,000 mPa·s at 25° C.

15. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , wherein the compounded amount of the component (D) is such that a content of cerium metals in the component (D) is from 0.005 to 0.15 mass % based on the total amount of the composition.

16. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , wherein the silicone gel-cured material is substantially transparent and has 30 to 100 of direct reading value of ¼ consistency defined by JIS K 2220.

17. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , further defined as the general lighting device.

18. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , further defined as the optical substrate.

19. The general lighting device, optical substrate, or photoelectric substrate according to claim 9 , further defined as the photoelectric substrate.