Patent ID: 11884550
Assignee: 3M INNOVATIVE PROPERTIES COMPANY
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 0:
1. A shaped gel article comprising a polymerized product of a casting sol, wherein the casting sol is positioned within a mold cavity during polymerization and wherein the shaped gel article retains both a size and a shape identical to the mold cavity (except in a region where the mold cavity was overfilled) when removed from the mold cavity, the casting sol comprising:
a) 2 to 65 weight percent surface modified silica particles based on a total weight of the casting sol, wherein the surface modified silica particles comprise a reaction product of silica particles having an average particle size no greater than 100 nanometers and a surface modification agent composition comprising a silane modification agent having a radically polymerizable group and wherein the surface modified silica particles are 50 to 99 weight percent silica and wherein the casting sol contains no more than 50 weight percent silica;
b) 0 to 40 weight percent polymerizable material based on the total weight of the casting sol, wherein the polymerizable material does not contain a silyl group;
c) 0.01 to 5 weight percent radical initiator based on the total weight of the casting sol; and
d) 30 to 90 weight percent organic solvent medium based on the total weight of the casting sol, wherein the surface modification agent composition, the polymerizable material, and the radical initiator are soluble in the organic solvent medium.