Apparatus and method for precision coating of ophthalmic lenses with photochromic coatings
A method of manufacturing an optical article ( 10 ) includes supplying a first coating composition (A) and supplying one or more additional coating compositions (B) to an ultrasonic discharge nozzle ( 102 ) of a coating apparatus ( 100 ). At least one of the first coating composition (A) and the one or more additional coating compositions (B) is a photochromic coating composition. The method includes mixing the first coating composition and the one or more additional coating compositions at the ultrasonic discharge nozzle ( 102 ) of the coating apparatus ( 100 ), and applying the mixture (C) of the first coating composition (A) and the one or more additional coating compositions (B) to at least a portion of the optical article ( 10 ) so as to provide a pattern ( 24 ) on the optical article upon exposure to actinic radiation. The mixture (C) of the first coating composition (A) and the one or more additional coating compositions (B) is applied from the ultrasonic discharge nozzle ( 102 ) as a controlled, predetermined pattern of atomized droplets.
1. A method of manufacturing an optical article, the method comprising:
supplying a first coating composition comprising a first curable resin composition in liquid form to an ultrasonic discharge nozzle of a coating apparatus;
supplying one or more additional coating compositions comprising one or more additional curable resin compositions in liquid form to the ultrasonic discharge nozzle of the coating apparatus, at least one of the first coating composition and the one or more additional coating compositions is a photochromic coating composition;
mixing and atomizing the first coating composition and the one or more additional coating compositions at an atomizing surface of the ultrasonic discharge nozzle of the coating apparatus to form an atomized mixture of the first coating composition and the one or more additional coating compositions; and
applying the atomized mixture of the first coating composition and the one or more additional coating compositions to at least a portion of the optical article so as to provide a gradient pattern on the optical article upon exposure to actinic radiation,
wherein the atomized mixture of the first coating composition and the one or more additional coating compositions is applied from the ultrasonic discharge nozzle as a controlled, predetermined gradient pattern of atomized droplets,
wherein the gradient pattern is formed by controlling a flow rate of the first coating composition in liquid form relative to a flow rate of the one or more additional coating compositions in liquid form supplied to the atomizing surface of the nozzle, and
wherein the first curable resin composition and the one or more additional curable resin compositions comprise an epoxide functional polymer or an active hydrogen functional polymer.
2. The method of claim 1 , wherein the gradient pattern is linear, curvilinear, radial, or a combination thereof.
3. The method of claim 1 , wherein controlling the flow rate of the first coating composition relative to the flow rate of the one or more additional coating compositions varies a concentration of the photochromic coating composition in the atomized mixture.
4. The method of claim 1 , wherein the atomized mixture of the first coating composition and the one or more additional coating compositions is applied on the optical article as a coating having uniform thickness.
5. The method of claim 1 , wherein the atomized mixture of the first coating composition and the one or more additional coating compositions is applied on the optical article as a coating having non-uniform thickness.
6. The method of claim 1 , wherein the atomized mixture of the first coating composition and the one or more additional coating compositions is applied on the optical article in a single pass or multiple passes.
7. The method of claim 1 , wherein when the first curable resin composition or the one or more additional curable resin compositions comprise the epoxide functional polymer, the first curable resin composition or the one or more additional curable resin compositions further comprise an epoxide reactive crosslinking agent comprising active hydrogens, or
wherein when the first curable resin composition or the one or more additional curable resin compositions comprise the active hydrogen functional polymer, the first curable resin composition or the one or more additional curable resin compositions further comprise a capped isocyanate functional crosslinking agent.
8. The method of claim 1 , wherein the optical article is selected from the group consisting of optical lenses, optical filters, windows, visors, mirrors, displays, and ophthalmic lenses.
9. The method of claim 1 , wherein the ultrasonic discharge nozzle has a frequency of 48-120 kHz.