Silicon oxide bearing on its surface partially or completely sylilated polysilicic acids chains

摘要

The silicon dioxide is treated by addition of a molar excess of a silylating agent with respect to surface silanol groups. A silicon dioxide (I) having partially or fully silylated polysilicic acid chains on its surface is characterized in that the sum of the silanol (SiOH) groups of the silicon dioxide surface and the grafted silylating agent residue of formula SiRa (2) is greater than the number of silanol groups on the surface of untreated silicon dioxide. Independent claims are included for: (i) a process for producing (I) by addition of a molar excess (with respect to silanol groups) of a silylating agent; (ii) toner containing (I); and (iii) crosslinkable silicone compositions and elastomers containing (I). R = hydrocarbon, optionally substituted; a = 1-3