| 摘要 |
PROBLEM TO BE SOLVED: To provide a curable polyorganosiloxane enabling a cured product to be formed, the cured product having good transparency, excellent light resistance, heat yellowing resistance and thermal shock resistance and no tackiness, to provided a curable resin composition using the same, and to provided luminous parts and an optical semiconductor device.SOLUTION: The polyorganosiloxane is represented by the average composition formula (1): RSiOand contains (A) a siloxane unit having at least a fluorine-substituted phenyl group as a substituent as Rin the average composition formula (1) and (B) a siloxane unit having in one molecule at least one curable functional group selected from the group consisting of an organic group containing a carbon-carbon double bond, an epoxy group, an episulfide group, a thiocarbonate group, a dithiocarbonate group and a trithiocarbonate group as a substituent as Rin the average composition formula (1), wherein the ratio between the contents of the components (A) and (B) is in a predetermined range. In the formula, Rs each independently represent a hydrogen atom, a halogen atom, a hydroxyl group or a monovalent organic group comprising one or more structures selected from the group of unsubstituted or substituted chain, branched and cyclic structures, and n is a positive number satisfying 1≤n<2. |
