Thermoplastic lens blocking material

US5754269A · 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: May 19, 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 thermoplastic ophthalmic lens blocking compositions that have many advantages over traditional metal alloy materials. Preferred compositions comprise a homopolymer or copolymer of epsiloncaprolactone, have a number average molecular weight between 3,000 and 100,000, and a polydispersity less than 10. The composition may also comprise one or more modifiers, fillers or heat absorbing materials. In one embodiment, the composition is used to fill the cavity between a preformed lens block and a lens. In another embodiment the composition is used to form a lens block. Methods of holding a lens blank are taught. Tapes that provide a receptive surface against which the composition may be adhered are disclosed.