Silicon dioxide which bears partially or fully silylated polysilicic acid chains on its surface
AssigneeWacker Chemie AG
InventorsHerbert Barthel, Mario Heinemann
Life of this patent
Estimating the term…
Abstract
The invention relates to silicon dioxide which bears partially or fully silylated polysilicic acid chains on its surface, wherein the sum of silanol groups of the silicon dioxide surface (SiOH) and grafted-on silylating agent radicals (SiRa) is greater than the number of silanol groups on the surface of untreated silicon dioxide, where a can be 1, 2 or 3 and R can be identical or different and are each a substituted or unsubstituted hydrocarbon radical.
Claims17
Treated silicon dioxide which bears partially or fully silylated polysilicic acid chains on its surface, wherein the sum of silanol groups of the treated silicon dioxide surface (SiOH) and grafted-on silylating agent radicals (SiRa) is greater than the number of silanol groups on the surface of untreated silicon dioxide, where a can be 1, 2 or 3 and R can be identical or different and are each a substituted or unsubstituted hydrocarbon radical.
A process for preparing silicon dioxide which bears partially or fully silylated polysilicic acid chains on its surface, comprising reacting a silylating agent in molar excess based on silanol groups present on the silicon dioxide, said reacting taking place in the presence of an equimolar amount of water based on the amount of silylating agent, and in the presence of at least one base, for a period of minimally 15 minutes wherein the sum of silanol groups of the silicon dioxide surface (SiOH) and grafted-on silylating agent radicals (SiRa) is greater than the number of silanol groups on the surface of untreated silicon dioxide, where a can be 1, 2 or 3 and R can be identical or different and are each a substituted or unsubstituted hydrocarbon radical.
Dependencies are inferred from the claim text.