Plasma surface treatment of silicone hydrogel contact lenses with a flexible carbon coating
First Claim
1. A method for treating the surface of a silicone hydrogel contact lens, which method comprises the sequential steps of:
- (a) subjecting the surface of the lens to a plasma oxidation reaction;
(b) subjecting the oxidized surface of the lens to a plasma polymerization reaction in a hydrocarbon atmosphere comprising a diolefin having four to eight carbon atoms in the effective absence of oxygen, to form a carbon layer having a thickness of at least 50 to 500 Angstroms; and
(c) rendering the carbon layer of step (b) hydrophilic by either subjecting the surface to a plasma oxidization or by a secondary coating of a hydrophilic polymer.
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Abstract
The present invention is directed to the surface treatment of silicone hydrogel contact lenses. In particular, the present invention is directed to a method of modifying the surface of a contact lens to increase its hydrophilicity by coating the lens with a carbon-containing layer made from a diolefinic compound having 4 to 8 carbon atoms. In one embodiment, an optically clear, hydrophilic coating is provided upon the surface of a silicone hydrogel lens by sequentially subjecting the surface of the lens to: a plasma oxidation reaction, followed by a plasma polymerization reaction in a the presence of a diolefin in the absence of air. Finally, the resulting carbon layer is rendered hydrophilic by a further plasma oxidation reaction or by the attachment of a hydrophilic polymer chains.
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Citations
6 Claims
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1. A method for treating the surface of a silicone hydrogel contact lens, which method comprises the sequential steps of:
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(a) subjecting the surface of the lens to a plasma oxidation reaction;
(b) subjecting the oxidized surface of the lens to a plasma polymerization reaction in a hydrocarbon atmosphere comprising a diolefin having four to eight carbon atoms in the effective absence of oxygen, to form a carbon layer having a thickness of at least 50 to 500 Angstroms; and
(c) rendering the carbon layer of step (b) hydrophilic by either subjecting the surface to a plasma oxidization or by a secondary coating of a hydrophilic polymer. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification