Method of making a contact lens material and a lens therefrom
OwnerJim I. Maininventor
Life of this patent
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Abstract
A new and improved contact lens is provided and is made by a process which uses a distillation step with an addition of a carbon decolorizing agent to the solution being distilled. The carbon decolorizing agent prevents curdling and removes impurities in the distillation step. The result is a contact lens with a very high water content and with good oxygen permeability characteristics.
Claims8
In a method of manufacturing a soft contact lens material from hydroxy-ethyl-methacrylate and a cross linking agent, the improvement comprising adding a carbon decolorizing agent to said hydroxy-ethyl-methacrylate to prevent it from curdling and gelling during distilling, and distilling the hydroxy-ethyl-methacrylate to leave a residue including the carbon decolorizing agent and to provide a hydroxy-ethyl-methacrylate distillate adapted for subsequent polymerization.
A method of manufacture of a contact lens blank having a water content of about 50% prior to hydration comprising the steps of:
- mixing and forming a solution having as a major component hydroxy-ethyl-methacrylate and having a substantially lesser amount of hydroxypropyl-methacrylate and having minor amounts of polyvinyl-acetate, polyvinyl-butyrol, ethyl-cellulose, and polypropylene-glycol;
- distilling the solution while it is heated and while the solution is kept moving to create a distillate;
- filtering the distillate;
- adding to the distillate minor amounts of cyclohexyl-methacrylate, ethylene-glycol-methacrylate, methacrylic-acid, and deperoxy-ethyl-hexoate and mixing the same to form a material for polymerizing and, polymerizing the last-formed material to form a lens blank.
A method of forming a contact lens blank comprising the steps of mixing a mixture for distillation having by volume a majority amount of hydroxy-ethyl-methacrylate, adding about 5.27% in volume of hydroxypropyl-methacrylate, adding about 0.75% in volume of polyvinyl-acetate, adding about 0.78% in volume of polyvinyl-butyrol, adding about 75% in volume of ethyl-cellulose, adding about 0.72% in volume of polypropylene-glycol, adding about 0.38% in volume of carbon-decolorizing-neutral-norit;
- while mixing maintaining in motion all of the above-mentioned materials, distilling the materials to leave behind a residue including the carbon decolorizing agent;
- collecting the distillate solution and adding thereto about 1.5% in volume of cyclohexyl-methacrylate, and about 0.50% in volume of ethylene-glycol-methacrylate, and about 4.88% in volume methacrylic-acid, and adding about 0.18% in volume of deperoxy-ethyl hexoate and then mixing these materials, and polymerizing the last-mentioned material to form a lens material.
Dependencies are inferred from the claim text.