Primer composition, adhering method, and electric/electronic part
A primer composition is provided. The primer composition comprises: (A) an organosiloxane block copolymer represented by the average unit formula: (R 1 2 SiO 2/2 ) a (R 2 SiO 3/2 ) b , wherein each R 1 and R 2 is independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, “a” is a number in the range of 0.40 to 0.90, “b” is a number in the range of 0.10 to 0.60, and “a+b”=1.00, and having 0.5 to 35.0 mol % of silicon atom-bonded hydroxyl groups or silicon atom-bonded alkoxy groups, in which resinous siloxane blocks are connected by linear siloxane blocks; (B) a curing catalyst; and (C) an organic solvent. The primer composition improves the adhesion of silicone-cured products to base materials of optical semiconductor elements, package materials, substrates etc., and can suppress peeling or cracking caused by heat cycles.
1. An article comprising a base material, a silicone cured product, and a primer layer adhering the silicone cured product to the base material,
wherein the primer layer comprises the reaction product of a primer composition comprising:
(A) an organosiloxane block copolymer represented by the average unit formula:
(R 1 2 SiO 2/2 ) a (R 2 SiO 3/2 ) b
wherein each R 1 and R 2 is independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, “a” is a number in the range of 0.40 to 0.90, “b” is a number in the range of 0.10 to 0.60, and “a+b”=1.00, having 0.5 to 35.0 mol % of silicon atom-bonded hydroxyl groups or silicon atom-bonded alkoxy groups, in addition to being a solid at 25° C. and having a softening point of 200° C. or lower, in which resinous siloxane blocks represented by the formula:
[R 2 SiO 3/2 ]
wherein R 2 is the same as above, are connected by linear siloxane blocks represented by the formula:
—(R 1 2 SiO 2/2 ) n —
wherein R 1 is the same as above, and “n” is a number in the range of 10 to 400;
(B) a curing catalyst, in an amount to promote curing of this composition; and
(C) an organic solvent; and
wherein the silicone cured product comprises the reaction product of a curable silicone composition different from the primer composition.
2. The article according to claim 1 , wherein R 1 in component (A) is an alkyl group and/or an aryl group.
3. The article according to claim 1 , wherein R 2 in component (A) is an aryl group.
4. The article according to claim 1 , wherein component (B) is a condensation reaction catalyst.
5. The article according to claim 1 , wherein component (C) is an aromatic hydrocarbon based solvent, or a mixed solvent of the aromatic hydrocarbon based solvent and an aliphatic hydrocarbon based solvent.
6. The article according to claim 4 , wherein the primer composition is a condensation reaction curable silicone composition.
7. The article according to claim 6 , wherein the curable silicone composition is a hydrosilylation reaction curable silicone composition.
8. The article according to claim 1 , wherein the base material is an electric/electronic part.
9. A method of forming the article according to claim 1 , with the article comprising the base material, the silicone cured product, and the primer layer adhering the silicone cured product to the base material, the method comprising:
applying the primer composition onto the base material;
removing the organic solvent (C) to obtain the primer layer; and
subsequently applying the curable silicone composition onto the primer layer for curing to form the silicone cured product.
10. The method according to claim 9 , wherein the curable silicone composition and the primer layer are simultaneously cured.
11. The article according to claim 8 , wherein the electric/electronic part is an optical semiconductor apparatus.
12. The article according to claim 2 , wherein R 2 in component (A) is an aryl group.