E.i. Dupont De Nemours and Company

Thomas C Bissot

Stephen Li

Paul R Resnick

James T Keating

Raimund H Silva

William E Grigsby

Walter G Grot

A barrier resin composition is disclosed is which contains 50 to 95 weight percent ethylene/vinyl alcohol copolymer having a melt flow of 0.1 to 100 g/10 minutes as measured at 210.degree. C. and 50 to 5 weight percent mica having a particle size of less than 74 microns and an aspect ratio of from 10 to 150. The composition can be prepared by melt blending a mixture of the ethylene/vinyl alcohol copolymer and the mica. Alternatively, the composition can be prepared by forming a dispersion of this mica in a solution of the ethylene/vinyl alcohol copolymer followed by precipitating the ethylene/vinyl alcohol copolymer.

Ethylene vinyl alcohol copolymers containing platelet-type mica fillers

A barrier resin composition is disclosed which contains 50 to 95 weight percent ethylene/vinyl alcohol copolymer having a melt flow of 0.1 to 100 g/10 minutes as measured at 210.degree. C. and 50 to 5 weight percent mica having a particle size of less than 74 microns and an aspect ratio of from 10 to 150. The composition can be prepared by melt blending a mixture of the ethylene/vinyl alcohol copolymer and the mica. Alternatively, the composition can be prepared by forming a dispersion of this mica in a solution of the ethylene/vinyl alcohol copolymer followed by precipitating the ethylene/vinyl alcohol copolymer.

Ethylene vinyl alcohol copolymers containing platelet-type mica fillers,

A presoaked perhalogenated polymer cation exchange membrane containing at least one type of acid groups, carboxyl or sulfonyl, is bonded to other articles such as edge-reinforcing tape, gasket, electrolytic cell frame, etc., by means of a pressure-sensitive adhesive material from the group of butyl rubber, styrene-butadiene rubber, and polyacrylate rubber. Presoaking of the membranes is done either in water or in an aqueous alkaline solution.

Edge reinforcement of membranes for chlor-alkali cells

In an improved process for the electrolysis of sulfate-containing brine in a membrane cell, the thickness of the membrane, the concentration of sodium sulfate in the brine and the current density through the membrane in the operating cell are controlled to prevent sulfate damage to the membranes.

Process for electrolysis of sulfate-containing brine

In an improved process for the electrolysis of silica-containing brine in a membrane cell, the thickness of the membrane, the concentration of silica, aluminum and calcium in the brine and the current density through the membrane in the operating cell are controlled to prevent silica damage to the membranes.

Process for electrolysis of silica-containing brine

Pre-swelled ion exchange membranes formed from one or more layers of fluorinated polymer having carboxylic or sulfonic acid functional groups and which polymer contains about 8 to 30% by weight of a swelling agent of the formula HO(CH.sub.2 CHYO).sub.n H where Y=H or CH.sub.3 and n=2, 3 or 4 are disclosed. Also disclosed are processes for preparing these membranes, electrochemical cells utilizing these membranes, and methods of preparing said cells for use in chloralkali processes.

Ion exchange membranes pre-expanded with di- and poly ether-glycols

Process for electrolysis of brine with iodide impurities

A reinforced ion exchange membrane which comprises fluorinated polymer which has carboxylic functional groups, which has a hydrogen bubble release layer on the cathode-facing side thereof, and which has channels open to the outer surface of the anode-facing side thereof, is described. Precursor membrane, which may contain partially embedded sacrificial members, and from which the reinforced ion exchange membrane is made, is also described. The reinforced ion exchange membrane can be used to separate the compartments of a chloralkali cell, and such a cell operates at low voltage, high current efficiency, and low power consumption.

Reinforced membrane, electrochemical cell and electrolysis process

An unreinforced ion exchange membrane which comprises fluorinated polymer which has carboxylic functional groups, which has a hydrogen bubble release layer on the cathode-facing side thereof, and which has channels open to the outer surface of the anode-facing side thereof, is described. Precursor membrane, which may contain partially embedded sacrificial members, and from which the unreinforced ion exchange membrane is made, is also described. The unreinforced ion exchange membrane can be used to separate the compartments of a chloralkali cell, and such a cell operates at low voltage, high current efficiency, and low power consumption.

Unreinforced membrane, electrochemical cell and electrolysis process

A membrane assembly which comprises a layer of perfluorinated polymer which has carboxylate functional groups, a layer of perfluorinated polymer which has ion exchange functional groups, and a water-containing or water-soluble stratum which lies between these two layers and joins them together, is described. Such a multilayered composite membrane is more simply made than conventional multilayered membranes having adherent layers, and provides for easy recovery of the component parts thereof. The membrane assembly is useful for separating the compartments of an electrochemical cell, especially a chloralkali cell.

Membrane assembly, electrochemical cell, and electrolysis process using

A fluorocarbon cation exchange membrane containing a sacrificial reinforcement for tear resistance which, in use as a cation exchange membrane for alkali metal chloride electrolysis, degrades to provide low voltage operation of the electrolytic cell.

Sacrificial reinforcements in cation exchange membrane

An ion exchange membrane which comprises a layer of fluorinated polymer which has carboxylic functional groups, a second layer of fluorinated polymer which has sulfonic or carboxylic functional groups at a surface layer, and a web of support material therein, and which has channels in the membrane which extend from window areas of the membrane to blind areas of the membrane occluded by members of the support material, is described. Precursor membrane which contains both reinforcement members and sacrificial members, and from which the ion exchange membrane is made, is also described. The ion exchange membrane can be used to separate the compartments of a chloralkali cell, and such a cell operates at low voltage, high current efficiency, and low power consumption.

Membrane, electrochemical cell, and electrolysis process

The invention provides an improved process for making an iron-activated cathode for a chloralkali cell, and an improved method for lowering the operating voltage of a chloralkali electrolysis cell, which comprises adding to the cathode compartment of the cell a solution of a water-soluble or caustic-soluble ferrite and passing an electric current through the cell. By virtue of the invention, the hydrogen overvoltage in the cell is lowered, and considerable operating improvement thereby attained.

Method for making a cathode, and method for lowering hydrogen

A surface impregnated catalyst consisting essentially of a catalyst support, a palladium-gold alloy distributed in a surface layer of the catalyst support extending less than about 0.5 millimeter from the surface, and alkali metal acetate are provided. The catalyst has substantially higher specific activity than prior art catalysts used for the production of vinyl acetate.

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Newark, DE, United States of America

Thomas C Bissot