Composition for hard type contact lens with wettable surface

• US 3,948,871 A
• Filed: 02/04/1974
• Issued: 04/06/1976
• Est. Priority Date: 04/21/1972
• Status: Expired due to Term

• Current Assignee: George H Butterfield and Son
• Original Assignee: George H Butterfield and Son
• Inventors: Butterfield, deceased, George H. Sr., Gordon, executor, by David, Butterfield, George H. Jr.
• Primary Examiner(s): Wong, Jr., Harry
• Application Number:
  US05/439,407
• Time in Patent Office: 792 Days
• Field of Search: 260/86.1 E, 264/1
• US Class Current: 526/240
• CPC Class Codes: C08L 33/12 Homopolymers or copolymers of methyl methacrylate
• CPC Class Codes: G02B 1/043 Contact lenses

Abstract

A contact lens of the hard type, but exhibiting wettable surface characteristics, is produced from a polymer composition consisting essentially of about 90% by weight methyl methacrylate and about 10% by weight of neutralized hydroxy ethyl methacrylate.

Claims

1. A contact lens composition consisting essentially of the polymerization product of from about 85% to about 95% by weight of methyl methacrylate and from about 5% to about 15% by weight of hydroxy ethyl methacrylate, the hydroxy ethyl methacrylate being substantially neutralized to a pH of between about 6.5 and about 8.5 prior to combining with the methyl methacrylate.

2. The contact lens composition of claim 1 wherein neutralization of said hydroxy ethyl methacrylate is achieved by reaction with at least one of the materials selected from the group consisting of alkali metal hydroxides and alkaline earth bases.

3. The contact lens composition of claim 1 wherein the polymerization product contains about 90% by weight of methyl methacrylate and about 10% by weight of hydroxy ethyl methacrylate.

4. The contact lens composition of claim 3 wherein the hydroxy ethyl methacrylate is neutralized with calcium hydroxide to a pH of between about 6.5 and 8.5 prior to combining with the methyl methacrylate.