| 摘要 |
The present invention is directed to provide a curable composition for encapsulating an optical semiconductor, which has excellent impact resistance and cracking resistance and provides a cured product having low gas permeability, and an optical semiconductor device using the cured product of the composition. The curable composition comprises: (A) a linear polyfluoro compound having at least two alkenyl groups per molecule and further having a perfluoropolyether structure in the backbone; (B) an organohydrogenpolysiloxane represented by chemical formula (1); (C) a platinum-group metal catalyst; and (D) an organopolysiloxane having a hydrogen atom bound directly to a silicon atom, monovalent perfluoroalkyl group or monovalent perfluoroxyalkyl group, and epoxy or trialkoxysilyl group or both thereof. The cured product of the composition has a hardness of 30-70 as determined by a type A durometer. In addition, the cured product of the composition having a thickness of 1 mm has a water permeation ratio of 10.0 g/m^2.day or less. |
