Hydrophilic silicones
AssigneeMinnesota Mining and Manufacturing Company
InventorsThomas T. Bryan, Harvey L. Anderson
Life of this patent
Estimating the term…
Abstract
Curable silicon prepolymers are made hydrophilic after cure by mixing the prepolymer with ethoxylated nonionic surface active agent or cationic or amphoteric fluorochemical surface active agent. The cured silicones have semipermanent hydrophilicity and are especially useful as dental impressions.
Claims18
A curable silicone composition comprising a mixture of (a) curable silicone prepolymer and (b) surfactant selected from the group consisting of (i) ethoxylated nonionic surface active agents containing one or more siloxane or perfluoroalkyl solubilizing groups and (ii) cationic or amphoteric fluorochemical surface active agents, said surfactant being present in sufficient amount and said ethoxylated nonionic surface active agent, if present, containing sufficient ethyleneoxy groups so that said composition, when cured, has a three minute water contact angle below about 65.degree..
A cured silicone composition, comprising polysiloxane polymer having dissolved or dispersed therein surfactant selected from the group consisting of (a) ethoxylated nonionic surface active agents containing one or more siloxane or perfluoroalkyl solubilizing groups and (b) cationic or amphoteric fluorochemical surface active agents, said surfactant being present in sufficient amount and said ethoxylated nonionic surface active agent, if present, containing sufficient ethyleneoxy groups so that said composition has a three minute water contact angle below about 65.degree., said composition having semipermanent hydrophilicity.
A method for making a dental impression, comprising the step of making a negative mold or orgal tissue using as said mold a curable silicone composition comprising a mixture of (a) RTV addition cure or condensation cure polysiloxane prepolymer and (b) surfactant selected from the group consisting of (i) ethoxylated nonionic surface active agents containing one or more siloxane or perfluoroalkyl solubilizing groups and (ii) cationic or amphoteric fluorochemical surface active agents, said surfactant being present in sufficient amount and said ethoxylated nonionic surface active agent, if present, containing sufficient ethyleneoxy groups so that said composition, when cured, has a three minute water contact angle below about 65.degree..
Dependencies are inferred from the claim text.