US 12,247,169 B2
Method for making photochromic contact lenses
Feng Jing, Alpharetta, GA (US); Frank Chang, Cumming, GA (US); and Houliang Tang, Cumming, GA (US)
Assigned to Alcon Inc., Fribourg (CH)
Filed by Alcon Inc., Fribourg (CH)
Filed on Apr. 25, 2024, as Appl. No. 18/645,497.
Application 18/645,497 is a division of application No. 17/335,628, filed on Jun. 1, 2021, granted, now 11,999,908.
Claims priority of provisional application 63/033,240, filed on Jun. 2, 2020.
Prior Publication US 2024/0287379 A1, Aug. 29, 2024
Int. Cl. B29D 11/00 (2006.01); C08F 230/08 (2006.01); C09K 9/02 (2006.01); G02B 1/04 (2006.01); B29K 83/00 (2006.01); B29K 105/00 (2006.01)
CPC C09K 9/02 (2013.01) [B29D 11/00134 (2013.01); C08F 230/085 (2020.02); G02B 1/043 (2013.01); B29K 2083/00 (2013.01); B29K 2105/0061 (2013.01); C09K 2211/14 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for producing photochromic silicone hydrogel contact lenses, the method comprising the steps of:
(1) obtaining a mold, wherein the mold has a first mold half with a first molding surface defining the anterior surface of a contact lens and a second mold half with a second molding surface defining the posterior surface of the contact lens, wherein said first and second mold halves are configured to receive each other such that a cavity is formed between said first and second molding surfaces;
(2) introducing a polymerizable composition into the cavity, wherein the polymerizable composition is a fluid composition which comprises
(a) from about 20% to about 40% by weight of at least one hydrophilic (meth)acrylamido monomer,
(b) from about 15% to about 30% by weight of at least one siloxane-containing (meth)acrylamido monomer,
(c) from about 15% to about 35% by weight of at least one polysiloxane vinylic crosslinker,
(d) from about 0.005% to about 1.0% by weight of at least one photochromic compound,
(e) from about 0.3% to about 1.5% by weight of at least one UV-absorbing vinylic monomer, and
(f) from about 0.05% to about 1.5% by weight of at least one an acyl germanium photoinitiator relative to the total weight of the polymerizable composition,
wherein the acyl germanium photoinitiator is capable of initiating a free-radical polymerization under irradiation with a light source including a light in the region of about 420 to about 500 nm, wherein the sum of the amounts of components (a) to
(f) is at least 96% by weight relative to total amount of all polymerizable components in the polymerizable composition, wherein the polymerizable composition has a curing time of about 50 seconds or less as determined in photo-rheology study using a LED light source which provide a visible light with a spectral centroid of about 452 nm and a total irradiance of about 54 mW/cm2; and
(3) irradiating the polymerizable composition in the mold for about 50 seconds or less with a visible light in a region of from 420 to 500 nm, so as to form the photochromic silicone hydrogel contact lens,
wherein the formed photochromic silicone hydrogel contact lens comprises an anterior surface defined by the first molding surface and an opposite posterior surface defined by the second molding surface and is capable of undergoing reversible change from a colorless or light-colored state to a colored state upon exposure to UV or HEVL irradiation.