Process for forming clear, wettable silicone hydrogel articles
AssigneeJohnson & Johnson Vision Care, Inc.
InventorsDiana Zanini, Karen Altheim
Life of this patent
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Abstract
The present invention is a process for forming ophthalmic devices such as contact lenses, comprising the steps of curing a reactive mixture comprising at least one silicone-containing component, at least one hydrophilic component and at least one protonated diluent or protonatable diluent having a Hansen solubility parameter, δp between about 2 and about 7 to form an ophthalmic device having an advancing contact angle of less than about 80°; contacting the ophthalmic device with an aqueous solution which is capable of changing the Hansen solubility parameter, δp of the protonated or protonatable co-diluent to enhance water solubility and removing said diluent(s) with said aqueous solution.
Claims24
A process comprising the steps of curing a reactive mixture comprising at least one silicone-containing component, at least one hydrophilic component and a diluent comprising at least one protonated diluent or protonatable diluent having a Hansen solubility parameter, δp between about 2 and about 7 and at least one co-diluent having a Hansen solubility parameter, δp between about 2 and about 7 to form an ophthalmic device having a haze value of less than 100% and an advancing contact angle of less than about 80°;
- contacting the ophthalmic device with an aqueous solution which is capable of changing the Hansen solubility parameter, δp of the protonated or protonatable co-diluent to enhance water solubility, wherein said aqueous solution comprises at least about 70% water and (a) a pH of about 7 to about 10 when said diluent comprises at least one protonated diluent or (b) a pH of about 4 to about 7 when said diluent comprises at least one protonatable diluents and removing said diluent(s) with said aqueous solution.
A process comprising the steps of reacting a reactive mixture comprising at least one silicone-containing component, at least one hydrophilic component, and at least one protonated diluent or protonatable diluent and about 7 and at least one co-diluent having a Hansen solubility parameter, δp between about 2 and about 7, to form an ophthalmic device having a haze value of less than 100% and an advancing contact angle of less than about 80°;
- and contacting the ophthalmic device with an exchange solution which is capable of changing the Hansen solubility parameter, δp of the protonated or protonatable diluent above water solubility wherein said exchange solution comprises at least about 70% water and (a) a pH of about 7 to about 10 when said diluent comprises at least one protonated diluent or (b) a pH of about 4 to about 7 when said diluent comprises at least one protonatable diluents.
Dependencies are inferred from the claim text.