Colored contact lenses and method of making the same
The present invention generally relates to a method for making colored contact lenses, in particular to colored silicone hydrogel contact lenses. The present invention is also related to a method of a first high intensity UV curing the colored print on the mold and a second high intensity UV treating mold for making colored silicone hydrogel contact lenses. The present invention illustrates the right combination of the first high intensity UV exposure and the second high intensity UV exposure allows a lens that maintains good ion permeability (IP) value and a good print quality.
1. A method of making colored silicone-hydrogel contact lenses, comprising the steps of:
(a) providing a mold assembly comprising a female mold half having a molding surface and a male mold half having a molding surface;
(b) applying at least one color coat to at least a portion of at least one of the female molding surface and the male molding surface with an ink, wherein the ink comprises at least one colorant and a silicone-containing polymer binder;
(c) irradiating the color coat on the molding surface with a first high intensity UV light to at least partially cure the color coat; and then
(d) irradiating exposed surfaces of the female mold and the male mold with a second high intensity UV light prior to step (e);
(e) filling a lens-forming fluid material comprising at least one silicone-containing vinylic monomer or macromer and at least one hydrophilic vinylic monomer into the irradiated mold assembly from step d);
(f) exposing the mold assembly and the lens-forming fluid material to an energy source, wherein the energy source polymerizes the lens-forming fluid material;
wherein an emission spectrum of the first high intensity UV light has a higher intensity in wavelength range of 320-390 nm by at least 200 mW/cm 2 and a lower intensity in wavelength range of 250-260 nm by at least 10 mW/cm 2 than the second high intensity UV light.
2. The method of claim 1 , wherein the intensity of the first high intensity UV light is about 650-750 mW/cm 2 at a wavelength range of about 320-390 nm, and about 35-45 mW/cm 2 at a wavelength of about 250-260 nm.
3. The method of claim 1 , wherein the first high intensity UV light irradiates the molding surface having the color coat for about from 1 to 25 seconds.
4. The method of claim 1 , wherein the first high intensity UV light irradiates the molding surface having the color coat for about from 2 to 10 seconds.
5. The method of claim 1 , wherein the intensity of the second high intensity UV light is about 150-600 mW/cm 2 at a wavelength range of about 320-390 nm, and about 45-125 mW/cm 2 at a wavelength of about 250-260 nm.
6. The method of claim 5 , wherein the second high intensity UV light irradiates the exposed surfaces of the female mold and the male mold for about from 0.1 to 20 seconds.
7. The method of claim 6 , wherein the second high intensity UV light irradiates the exposed surfaces of the female mold and the male mold for about from 0.5 to 5 seconds.
8. The method of claim 1 , wherein an energy of the first high intensity UV light is about 400-800 mJ/cm 2 at a wavelength range of about 320-390 nm.
9. The method of claim 8 , wherein the energy of the second high intensity UV light is about 15-75 mJ/cm 2 at a wavelength range of about 250-260 nm.
10. The method of claim 1 , wherein the time between step (c) and (d) is between 0.5 to 96 hours in order to obtain a high-quality color print image on the lens.
11. The method of claim 1 , wherein the time between step (c) and (d) is between 20 to 26 hours in order to obtain a high-quality color print image on the lens.
12. The method of claim 1 , wherein the time between step (c) and (d) is between 2 to 4 hours in order to obtain a high-quality color print image on the lens.