LENS MOLDS HAVING ATMOSPHERIC PLASMA COATINGS THEREON
First Claim
1. A method for producing ophthalmic lenses, comprising the steps of:
- (1) obtaining a mold for cast-molding contact lenses from a lens formulation, wherein the mold comprises a first mold half having a first molding surface and a second mold half having a second molding surface, wherein when the first and second mold halves are configured to receive each other such that a lens forming cavity is formed between the first molding surface and the second molding surface;
(2) increasing the hydrophobicity of at least one of the first and second molding surfaces by air plasma treatment which is carried out by generating an atmospheric plasma flow from a working gas and introducing the atmospheric plasma flow to at least one of the first and second molding surfaces of the mold to form a plasma coating on the molding surface under treatment, wherein the coated molding surface has an average water contact angle greater than an untreated molding surface and has an average water contact angle of about 55 degrees or greater;
(3) introducing a lens formulation into the lens-forming cavity formed between the first and second molding surfaces at least one of which has the plasma coating thereon;
(4) curing the lens formulation in the cavity to form an ophthalmic lens; and
(5) opening the mold and removing the molded ophthalmic lens, wherein the method is characterized by having a reduction in mold separation force (Δ
F %) of at least about 40%, wherein Δ
F % is determined according to the formula of
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Accused Products
Abstract
The invention provides a method of making ophthalmic lenses with an enhanced quality and enhanced yield achieved by reducing mold separation force and lens-mold adhesion. The method comprises the steps of generating an atmospheric plasma flow from a working gas and controlling the continuity of the atmospheric plasma flow with a power generator, and, introducing the atmospheric plasma flow to a molding surface of a mold for making an ophthalmic lens (preferably contact lens, more preferably a silicone hydrogel contact lens) and increasing the surface hydrophobicity of the molding surface of the mold and thereby to reduce a mold separation force after molding a lens formulation in the mold.
11 Citations
20 Claims
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1. A method for producing ophthalmic lenses, comprising the steps of:
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(1) obtaining a mold for cast-molding contact lenses from a lens formulation, wherein the mold comprises a first mold half having a first molding surface and a second mold half having a second molding surface, wherein when the first and second mold halves are configured to receive each other such that a lens forming cavity is formed between the first molding surface and the second molding surface; (2) increasing the hydrophobicity of at least one of the first and second molding surfaces by air plasma treatment which is carried out by generating an atmospheric plasma flow from a working gas and introducing the atmospheric plasma flow to at least one of the first and second molding surfaces of the mold to form a plasma coating on the molding surface under treatment, wherein the coated molding surface has an average water contact angle greater than an untreated molding surface and has an average water contact angle of about 55 degrees or greater; (3) introducing a lens formulation into the lens-forming cavity formed between the first and second molding surfaces at least one of which has the plasma coating thereon; (4) curing the lens formulation in the cavity to form an ophthalmic lens; and (5) opening the mold and removing the molded ophthalmic lens, wherein the method is characterized by having a reduction in mold separation force (Δ
F %) of at least about 40%, wherein Δ
F % is determined according to the formula of - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification