Epoxy resin compositions containing highly transparent silica-titania glass beads.

摘要

High transparency silica-titania glass beads are characterized by a linear transmittance of at least 70% as measured at a wavelength of 900 nm to 600 nm by a specific measurement method. Such beads are prepared by hydrolyzing and polycondensing a silicon alkoxide and a titanium alkoxide to form a silica-titania sol, converting the sol into a dry gel, and then grinding the gel followed by heating or heating the gel followed by grinding. A light transmission epoxy resin composition comprising a curable epoxy resin, a curing agent, and the high transparency silica-titania glass beads has crack resistance and high transparency in cured state. It is useful in encapsulating optical semiconductor devices.