Surface treatment of fluorinated contact lens materials
AssigneeBausch & Lomb Incorporated
InventorGeorge L. Grobe III
Life of this patent
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Abstract
Hydrogen-plasma modification of a contact lens made from a fluorinated polymer reduces the surface chemistry of by removing fluorine, leaving behind a carbon-enriched surface that is further plasma processed into a hydrophilic surface for a lens material to be inserted into the ocular environment.
Claims23
A method for treating the surface of a fluorinated contact-lens surface comprising the following steps:
- (a) plasma treating the surface of the lens with a hydrogen-containing atmosphere for a total time period of at least 2 minutes, at a wattage of greater than 25 watts and a pressure of 0.1 to 1.0 torr, to reduce the fluorine content or C—F bonding content by at least 25 percent over the first 74 angstroms of the surface as determined by XPS analysis;
- (b) oxidizing the surface with an oxygen or nitrogen-containing gas or gaseous mixture.
A fluorinated contact lens containing a surface coating, which when the lens is in the unhydrated state, is characterized by a fluorine content or a C—F bonding content within a depth of about 74 angstroms that is at least 25 percent depleted relative to the bulk material and an oxygen or nitrogen content within a depth of about 74 angstroms that is at least 2 percent enriched relative to the bulk material, as determined by XPS analysis, which enriched oxygen or nitrogen content provides the contact lens with improved wettability or biocompatibility.
A fluorinated contact lens containing a surface coating, which when the lens is in the unhydrated state, is characterized by a fluorine content or C—F bonding content within a depth of about 74 angstroms that is at least 25 percent depleted relative to the bulk material, as determined by XPS analysis, and which conact lens is further characterized by hydrophilic polymers attached to the surface of the contact lens though oxygen or nitrogen containing moieties to provide the contact lens with improved wettability or biocompatibility.
Dependencies are inferred from the claim text.