POLYSILOXANE COMPOSITION, HARDENED MATERIAL AND OPTICAL DEVICE

摘要

Disclosed is a polysiloxane composition which exhibits high heat-resistance and light-resistance, and excellent gas barrier properties. The disclosed polysiloxane composition includes: a polyhedral polysiloxane modified product (A) formed by modifying an alkenyl group-containing polyhedral polysiloxane compound (a) with a compound (b) having a hydrosilyl group; and an organopolysiloxane (B) having at least two alkenyl groups in a molecule. The composition is characterised in that: the post-hardening water-vapour permeability is not more than 30g/m2/24 h, the organopolysiloxane in component (B) is an organopolysiloxane (B1) containing an aryl group, and/or a component (C) is included, which is an organosilicon compound (C1) having one hydrosilyl group or alkenyl group in a molecue, or a cyclic olefin compound (C2) having one carbon-carbon double bond in a molecule.