Diamond Shamrock Corporation

Charles J Hora

Andrew D Babinsky

Kevin J O'Leary

Donald L DeRespiris

Thomas G Strempel

Joseph P Tiefenbach

Charles L Sieglaff

Edward J Peters

Nancy J Drake

Wayne P Zeman

Soft contact lenses resistant to opacification in use

In an electrolytic cell of the membrane type wherein the anolyte and catholyte are separated by a hydraulically impermeable membrane, the improvement comprising limiting the hydraulically impermeable membrane portion of the divider between anolyte and catholyte chambers to that area which is between the active areas of the anode and cathode while all other areas between catholyte and anolyte chambers are nonpermeable so as to minimize back-migration of undesirable ions which decrease overall current efficiency. Specifically, in a chlor-alkali cell an electrode would be enclosed in a fluorinated ethylene propylene enclosure having window-like openings therein made from Nafion type hydraulically impermeable cation exchange membrane, said window-like openings exposing only active electrode areas.

Membrane assembly for electrolytic cells

An alkali metal carbonate substantially free of alkali metal chloride is efficiently produced by electrolyzing an alkali metal chloride in an electrolytic cell having anolyte and catholyte compartments separated by a cation-exchange hydraulically impermeable membrane comprised of a thin film of a fluorinated polymer having pendant carboxylic acid or alkali metal carboxylate groups and a cathode spaced apart from the membrane, injecting into the catholyte compartment of the cell carbon dioxide in a quantity sufficient to convert substantially all the alkali metal hydroxide forming therein to the alkali metal carbonate salt, and utilizing a magnitude of electrolyzing current that reduces alkali metal chloride in the catholyte solids to less than 400 ppm.

Production of alkali metal carbonates in a cell having a carboxyl

Disclosed are a sulfonyl group containing fluorocarbon polymer cation-exchange membrane which has been fabric reinforced and, on one side of which has been treated, after the fabric reinforcing has been applied in a heat-pressure application, to a depth of at least 10 microns with a primary amine or a secondary amine or mixtures thereof to aminate a majority of said sulfonyl groups.

Reverse-side treatment of fabric reinforced membranes

Polymer hydrogels adapted for use as soft contact lenses are treated to provide at least on the surfaces thereof a modified, less hydrophilic polymeric structure inhibiting penetration by bacteria and proteins, whereby development of clouding and discoloration of the lens material is significantly retarded in use.

Surface-treated soft contact lenses

Disclosed is an improved wafer electrode for use in an electrolytic cell, having an access tube to direct a fluid across the electrode plate or to remove fluid from near the electrode plate within the cell. Cells employing the subject wafer electrode in an electrolytic cell can be used for various electrochemical processes such as for the production of alkali metal carbonates.

Wafer electrode for an electrolytic cell

Polymer hydrogels adapted for use as soft contact lenses are treated to provide at least on the surfaces thereof a modified, less hydrophilic polymeric structure inhibiting penetration by bacteria and proteins, whereby development of clouding and discoloration of the lens material is significantly retarded.

Disclosed are a sulfonyl group containing fluorocarbon polymer cation-exchange membrane, one side of which has been amine treated to a depth of at least 10 microns, as well as a chlor-alkali electrolytic cell employing same.

Polyamine modified membranes and chlor-alkali electrolysis cells

An alkali metal carbonate substantially free of alkali metal chloride is efficiently produced by electrolyzing an alkali metal chloride in an electrolytic cell having anolyte and catholyte compartments separated by a cation-exchange hydraulically impermeable membrane comprised of a thin film of a fluorinated polymer having pendant sulfononate groups and a cathode spaced apart from the membrane, injecting into the catholyte compartment of the cell carbon dioxide in a quantity sufficient to convert substantially all of the alkali metal hydroxide forming therein to the alkali metal carbonate salt, and utilizing a magnitude of electrolyzing current that reduces alkali metal chloride in the carbonate salt to less than 400 ppm.

Production of alkali metal carbonates in a membrane cell

Cation-exchange membranes for use in the electrolysis of alkali metal chloride solutions are treated in order to introduce hydrated alkali metal ions throughout the membrane and are subsequently installed in a cell and subjected to an applied voltage not in excess of about 6.5 to 8.5, passage of current and electrolysis occurring immediately.

Growing community of inventors

Willoughby Hills, OH, United States of America

Charles J Hora