Process for preparing a photochromic lens

US6367930B1 · kind B1 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Pia I. Santelices · Portland, US
• James N. Rieck · Wheeling, US
• Jack C. Chan · Peachtree City, US
• Sivaram Krishnan · Pittsburgh, US
• William G. Curtis · Dorpsstraat, US
• Robert A. Pyles · Bethel Park, US

Key dates

• Filing date: Dec 30, 1999
• Grant date: Apr 9, 2002
• Expiry date: Dec 30, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B5/23
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A process for making a photochromic optical lens is disclosed. In a first embodiment of the process a multi-plied laminate, containing a ply of photochromic thermoplastic polyurethane (herein “TPU”) and a ply containing thermoplastic polycarbonate, is first placed in the cavity of a suitable mold. The ply that contains polycarbonate resin is placed facing the cavity. Thermoplastic polycarbonate resin is then injected into the cavity. In a second embodiment, referred to as an over-mold method, polycarbonate is first injection molded into a molding cavity to form a substrate. Photochromic TPU is, in a subsequent step, injected into the cavity to form a superstrate overlay. In both embodiments, the articles thus molded are suitable for the preparation of optical lenses.