COMPOSITIONS OF RESIN-LINEAR ORGANOSILOXANE BLOCK COPOLYMERS

摘要

Curable compositions of “resin-linear” organosiloxane block copolymers comprising a nanoparticulate filler are disclosed. In some instances, even at high loading levels, curable and solid compositions comprising “resin linear” organosiloxane block copolymers and a nanoparticulate filler exhibit melt flow and cure behavior. In addition, the nanoparticulate filler present in the curable and solid compositions comprising “resin linear” organosiloxane block copolymers have the effect of significantly in creasing the refractive index of the curable and solid compositions.

主权项

1. A curable composition comprising:
i) an organosiloxane block copolymer comprising:
40 to 90 mole percent disiloxy units of the formula [R12SiO2/2],10 to 60 mole percent trisiloxy units of the formula [R2SiO3/2];
wherein:
each R1, at each occurrence, is independently a C1 to C30 hydrocarbyl,each R2, at each occurrence, is independently a C1 to C20 hydrocarbyl;wherein:the disiloxy units [R12SiO2/2] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R12SiO2/2] per linear block,the trisiloxy units [R2SiO3/2] are arranged in non-linear blocks having a molecular weight of at least 500 g/mole, and at least 30% of the non-linear blocks are crosslinked with each other, each linear block is linked to at least one non-linear block; and ii) a nanoparticulate filler.