Mold for casting contact lenses utilizing and electron beam to polymerize the resin lens

• US 4,017,238 A
• Filed: 04/21/1975
• Issued: 04/12/1977
• Est. Priority Date: 04/21/1975
• Status: Expired due to Term

• Current Assignee: CIBA Vision Corporation (Novartis Ag)
• Original Assignee: American Optical Corporation
• Inventors: Robinson, Charles C.
• Primary Examiner(s): Shore, Ronald J.
• Assistant Examiner(s): Brown, John S.
• Application Number:
  US05/570,042
• Time in Patent Office: 722 Days
• Field of Search: 427/135, 29/196.9, 29/199, 249/116, 425/174.6, 425/808, 425/174.8 R, 425/174.8 E, 164/19, 164/46, 264/22, 264/337, 264/219, 264/232, 264/1
• US Class Current: 425/174.6
• CPC Class Codes: B29C 2035/0877 using electron radiation, e.g. beta-rays
• CPC Class Codes: B29C 33/60 Releasing, lubricating or separating agents in general C10M
• CPC Class Codes: B29C 35/0888 using transparant moulds
• CPC Class Codes: B29D 11/00038 Production of contact lenses
• CPC Class Codes: B29K 2083/00 Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
• CPC Class Codes: B29K 2909/08 Glass
• CPC Class Codes: Y10S 425/808 Lens mold

Abstract

A mold for casting contact lenses from an unpolymerized resin such as silicone gum wherein the resin is polymerized by high energy radiation such as an electron beam. One part of the mold is a cap capable of transmitting such radiation. The male section of the mold is gold plated to minimize reaction between the resin and the male section under the influence of the electron beam.

Claims

1. A mold including a thin-walled cap member and a base member for casting contact lenses and the like by forming the lens within the mold from unpolymerized resin and subsequently polymerizing the resin while it is within the mold by the action of an electron beam directed against the thin-walled mold member and passing therethrough to act upon the resin, wherein said base member comprises:

a stainless steel member having a surface shaped to conform with one surface of the lens being cast within the mold and being susceptible to pitting when acted on by an electron beam in the presence of a resin; and

a layer of inert metal covering said surface to protect the surface from the pitting resulting from the action of the electron beam.

2. The mold defined in claim 1 wherein the inert metal is gold.

3. The mold defined in claim 2, wherein:

the stainless steel member has a nickel chromium layer deposited on the surface to form an underlayer whereon the layer of gold is deposited.