Acid efficient membrane for use in electrodialysis for recovery of acid

Claim 2

The process for preparing a aliphatic, weak base anion exchange polymeric membrane of low void volume, high ion exchange capacity and low electrical resistance having a woven or non-woven cloth reinforcing structure, the polymer of said membrane prepared by the process comprising copolymerizing in the absence of non-polymerizable solvents about 50 to 90 mol percent of at least one multiple-ethylenic cross-linking monomer compound selected from the group consisting of ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tri methylol propane trimethacrylate, methylene bismethacrylamide, neopentyl glycole dimethacrylate, bis-phenol A dimethacrylate, pentaerythritol trimethacrylate and penta erythritol tetra methacrylate with about 50 to about 1 mol percent respectively of a methacrylate ester salt monomer compound of the formula: ##STR4## Where R is an ion exchange moeity of a non-quarternized ammonium group selected from primary, secondary and tertiary amines, said resulting solvent free polymer having substantially no inherent voids due to the absence of non-polymerized solvents in the monomers during manufacture.

Claim 3

An electrodialysis apparatus for recovering acid values comprising at least one aliphatic, weak base anion exchange polymeric membrane of low void volume, high ion exchange capacity and low electrical resistance having a woven or non-woven cloth reinforcing structure, the polymer of said membrane prepared by the process comprising copolymerizing in the absence of non-polymerizable solvents about 50 to 99 mol percent of at least one multiple-ethylenic cross-linking monomer compound selected from the group consisting of ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tri methylol propane trimethacrylate, methylene bismethacrylamide, neopentyl glycol dimethacrylate, bis-phenol A dimethacrylate, pentaerythritol trimethacrylate and penta erythritol tetra methacrylate with about 50 to about 1 mol percent respectively of a methacrylate ester salt monomer compound of the formula: ##STR5## Where R is an ion exchange moeity of a non-quaternized ammonium group selected from primary, secondary and tertiary amines, said resulting solvent free polymer having substantially no inherent voids due to the absence of non-polymerized solvents in the monomers during manufacture.

Claim 4

An electrodialysis apparatus for recovering acid values comprising at least one aliphatic, weak base anion exchange polymeric membrane of low void volume, high ion exchange capacity and low electrical resistance having a woven or non-woven cloth reinforcing structure, the polymer of said membrane prepared by the process comprising copolymerizing in the absence of non-polymerizable solvents about 50 to 99 mol percent of at least one multiple-ethylenic cross-linking monomer compound selected from the group consisting of ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tri methylol propane trimethacrylate, methylene bismethacrylamide, neopentyl glycol dimethacrylate, bis-phenol A dimethacrylate, pentaerythritol trimethacrylate and penta erythritol tetra methacrylate with about 50 to about 1 mol percent respectively of a methacrylate ester salt monomer compound of the formula: ##STR5## Where R is an ion exchange moeity of a non-quaternized ammonium group selected from primary, secondary and tertiary amines, said resulting solvent free polymer having substantially no inherent voids due to the absence of non-polymerized solvents in the monomers during manufacture.