Molds for making contact lenses

Patent metadata

Field	Value
Publication number	US-10160141-B2
Application number	US-201514941716-A
Country	US
Kind code	B2
Filing date	Nov 16, 2015
Priority date	Nov 25, 2014
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

The present invention general related to a mold for making a contact lens comprises a first mold half having a first mold surface in contact with a polymerizable and/or crosslinkable silicone containing lens forming composition and a second mold half having a second mold surface in contact with the lens-forming composition, and 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. At least one of the mold halves is made from a sulfur containing polymer having a refraction index greater than 1.5. The dimension stability of the plastic mold can be improved.

First claim

What we claim is:

1. A 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 silicone containing lens-forming composition, 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 the silicone containing lens forming composition is polymerizable and/or crosslinkable by actinic radiation or thermal energy, wherein at least one of the mold halves is made from a sulfur containing polymer having a refraction index greater than 1.5, wherein the sulfur containing polymer is thiourethane or episulfide.

2. The mold for making a contact lens according to claim 1 , wherein the thiourethane or episulfide having a refraction index greater than 1.6.

3. The mold for making a contact lens according to claim 1 , wherein thiourethane or episulfide having a refraction index greater than 1.7.

4. The mold for making a contact lens according to claim 1 , wherein the sulfur containing polymer is episulfide.

5. The mold for making a contact lens according to claim 1 , wherein the sulfur containing polymer is thiourethane.

6. The mold for making a contact lens according to claim 1 , wherein the mold is prepared by single point diamond turning.

7. A method for producing a contact lens, comprising: the steps of:
(1) providing a contact lens 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 a sulfur containing polymer having a refraction index greater than 1.5, wherein the sulfur containing polymer is thiourethane or episulfide,
(2) introducing a silicone containing lens-forming composition into the cavity formed by the first and second molding surfaces, material, wherein the silicone containing lens-forming material is crosslinkable and/or polymerizable by actinic radiation or thermal energy;
(3) crosslinking/polymerizing the silicone containing 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.

8. The method for making a contact lens according to claim 7 , wherein the thiourethane or episulfide having a refraction index greater than 1.6.

9. The method for making a contact lens according to claim 7 , wherein the thiourethane or episulfide having a refraction index greater than 1.7.

10. The method for making a contact lens according to claim 7 , wherein the mold is prepared by single point diamond turning.

Assignees

• Novartis Ag

Inventors

• Liu Alice Weimin
• Herron Gregory L

Classifications

• B29C33/38 Primary

  characterised by the material or the manufacturing process (B29C33/44 takes precedence) · CPC title

• B29D11/005

  having means for aligning the front and back moulds · CPC title

• B29D11/00134

  Curing of the contact lens material · CPC title

• B29K2881/00

  Use of polymers having sulfur, with or without nitrogen, oxygen, or carbon only, in the main chain, as mould material · CPC title

• B29K2995/0031

  Refractive · CPC title