Reusable lens molds and methods of use thereof

Patent metadata

Field	Value
Publication number	US-9981435-B2
Application number	US-201514970808-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Dec 17, 2014
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

The present invention general related to a method and a reusable mold for making a contact lens, comprising a first mold half having a first mold surface in contact with a silicone containing lens forming composition and a second mold half having a second mold surface in contact with the lens forming composition. The first mold half and the second mold half are configured to receive each other such that a cavity is formed between the first mold surface and the second mold surface. The cavity defines the shape of a contact lens to be molded. The lens forming composition is polymerizable and/or crosslinkable by actinic radiation. The reusable mold has at least one of the mold halves is made from chalcogenide glasses, Zinc Selenide or Zinc Sulfide.

First claim

I claim:

1. A method for producing a contact lens, comprising: the steps of:
(1) providing a contact lens reusable mold, wherein the mold comprising a first mold half having a first mold and a second mold half having a second mold surface, wherein the first mold half and the second mold half are configured to receive each other such that a cavity is formed between the first mold surface and the second mold surface, wherein the cavity defines the shape of a contact lens to be molded, wherein at least one of the mold halves is made from chalcogenide glasses or Zinc Sulfide,
(2) introducing a silicone-containing lens-forming composition into the cavity formed by the first and second molding surfaces, wherein the lens-forming material is crosslinkable and/or polymerizable by actinic radiation;
(3) crosslinking/polymerizing the lens-forming material in the mold to form a lens having a polymer matrix;
(4) opening the mold and removing the formed contact lens from the mold, wherein the formed contact lens is characterized by having a clean lens edge without flash.

2. The method for producing a contact lens according to claim 1 , wherein the mold half is made from Zinc Sulfide.

3. The method for producing a contact lens according to claim 1 , wherein the mold half has a UV transmission cut-off wavelength no less than 350 nm.

4. The method for producing a contact lens according to claim 1 , wherein the mold half single point diamond turned to produce optical quality surfaces.

5. The method for producing a contact lens according to claim 1 , wherein the lens-forming composition comprises at least one components selected from the group consisting of a silicone-containing vinylic monomer, a silicone-containing vinylic macromer, a silicone-containing prepolymer, a hydrophilic vinylic monomer, a hydrophobic vinylic monomer, a crosslinking agent, a free-radical initiator (photoinitiator or thermal initiator), a hydrophilic vinylic macromer/prepolymer, and combinations thereof.

6. The method for producing a contact lens according to claim 5 , wherein the lens-forming composition further comprises at least one UV-absorbing vinylic monomer that absorbs ultraviolet light.

7. The method for producing a contact lens according to claim 6 , wherein the lens-forming composition further comprises at least one germanium-based Norrish Type I photoinitiator.

8. The method for producing a contact lens according to claim 1 , wherein the lens-forming composition is crosslinked and/or polymerized by UV LED in a region from 380 nm to 550 nm.

9. The method for producing a contact lens according to claim 7 , wherein the lens-forming composition is crosslinked and/or polymerized by UV LED with a total intensity from about 10 to about 100 mW/cm 2 in the region from 380 nm to 550 nm.

10. The method for producing a contact lens according to claim 7 , wherein the lens-forming composition is crosslinked and/or polymerized by UV LED with a total intensity from about 20 to about 60 mW/cm 2 in the region from 380 nm to 550 nm.

11. The method for producing a contact lens according to claim 7 , wherein the lens-forming composition is crosslinked and/or polymerized by UV LED in less than 120 seconds.

Assignees

• Novartis Ag

Inventors

• Liu Alice Weimin

Classifications

• B29K2995/0027

  for light outside the visible spectrum · CPC title

• B29K2909/08

  Glass · CPC title

• B29D11/00038 Primary

  Production of contact lenses · CPC title

• B29C35/0888

  using transparant moulds · CPC title

• B29C2035/0827

  using UV radiation · CPC title