Method of holding an ophthalmic lens blank

US5827390A · kind A · utility

Assignee

• Minnesota Mining and Manufacturing Company · US

Inventors

• Sharon R. Benjamin · Oakdale, US
• Michael Govek · Lakeville, US
• Patrick D. Hyde · Mendota Heights, US
• John H. Ko · Woodbury, US
• Philip G. Martin · Forest Lake, US
• Joel D. Oxman · Minneapolis, US
• William L. Parish · Maplewood, US
• Carole Sedlock · Minneapolis, US
• Richard L. Severance · Stillwater, US
• F. Andrew Ubel, III · Windom, US
• Todd R. Williams · Lake Elmo, US

Key dates

• Filing date: Sep 13, 1996
• Grant date: Oct 27, 1998
• Expiry date: Sep 13, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2891
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The present invention provides methods of holding ophthalmic lens blanks using thermoplastic lens blocking compositions. Preferred compositions either comprise a homopolymer or copolymer of epsilon-caprolactone, have a number average molecular weight between 3,000 and 100,000, or have a polydispersity less than 10. The composition may also comprise one or more modifiers, fillers or heat absorbing materials. In one method, the composition is injected into the cavity between a preformed lens block and a lens. In another method, the surface of a lens block comprising the thermoplastic lens blocking composition is heated and formed against the lens blank. Tapes that provide a receptive surface against which the composition may be adhered are disclosed.