17-01-2019 дата публикации
Номер: US20190016074A1
Принадлежит:
The invention is directed to a reusable mold for making a contact lens and the reusable mold has at least one of the mold halves is made from an oxide glass having a Knoop Hardness less than HK 350. The invention is also directed to a method for making an optical part by single point diamond turning an oxide glass having a Knoop Hardness HK less than 350. 18-. (canceled)9. A method for making a reusable mold for making a contact lens comprising the steps of:(a) selecting an oxide glass material having a Knoop Hardness less than 350 for the reusable mold for making a contact lens, (b) single point diamond turning the oxide glass with a neutral or negative rake angle to achieve an optical part having an optical quality surface.10. The method of claim 9 , wherein the optical part is a reusable mold for making contact lens.11. The method of claim 10 , wherein the Knoop Hardness is less than 340.12. The method of claim 11 , wherein the Knoop Hardness is less than 320.13. The method of claim 9 , wherein the rake angle is from 0° to −25°.14. The method of claim 9 , wherein the optical part has a surface roughness (Ra) less than 30 nm.15. The method of claim 14 , wherein the optical part has a surface roughness (Ra) less than 20 nm.16. The method of claim 15 , wherein the optical part has a surface roughness (Ra) less than 10 nm. This application claims the benefit under 35 USC 119 (e) of U.S. provisional application number 61/918,914 filed 20 Dec. 2013, incorporated by reference in its entirety.A great effort has been made to develop technologies for cast molding of hydrogel contact lenses with high precision, fidelity and reproducibility and at low cost. One of such manufacturing technologies is the so-called Lightstream Technology™ (Alcon) involving reusable molds and curing a lens-forming composition under a spatial limitation of actinic radiation (U.S. Pat. Nos. 5,508,317, 5,583,163, 5,789,464, 5,849,810 and 8,163,206). The Lightstream Technology™ for making contact ...
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