Process for the production of a semipermeable membrane on a porous conductive support by electrophoresis

Process for the production of a microfiltration, ultrafiltration or reverse osmosis element, constituted by a semipermeable mineral membrane on a porous conductive support, comprising the steps of:

• a) preparing a dispersion by finely dispersing in an aqueous or hydroorganic medium insoluble solid mineral products in the presence of an electrodepositable coating resin to coat the mineral products with the resin;
• b) utilizing the dispersion of a) as the electrophoretic medium of an electrophoresis bath;
• c) depositing, by electrophoresis, on the interior of a tubular porous conductive support subjected to the electrophoresis bath, at least a coating of electrodeposited solid mineral products with only slight penetration and imbrication of the solid mineral products layer with the porous conductive support;
• and
• d) heat treating the conductive support and its deposited coating to eliminate volatiles and sintering the coating of finely divided mineral solid products.

Microfiltration, ultrafiltration or reverse osmosis element, comprising a semipermeable mineral material on a porous conductive support, produced by a process comprising the steps of:

• a) dispersing one or more inert solid mineral products in a liquid medium comprising water or water mixed with at least partly hydrosoluble organic solvents and an electrodepositable, hydrosoluble coating resin to coat said mineral products with said resin;
• b) preparing an electrophoresis bath comprising the at least partly hydrosoluble organic solvents and said coating resin with said resin coated solid mineral product finely dispersed in the liquid medium;
• c) contacting the interior of a tubular porous conductive support with said electrophoresis bath with the porous conductive support as an electrode, said bath having a metal counterelectrode, over the entire surface of the porous conductive support in contact with the electrophoresis bath and depositing by electrophoresis on the porous support at least a layer of said electrodepositable resin-coated solid mineral products with only slight penetration and imbrication of the solid mineral products layer into the porous support;
• and
• d) heat treating said porous conductive support covered with the at least one layer of solid mineral product coated with an electro-coagulated resin to eliminate the water, the residual organic solvents and the organic materials, followed by the sintering of the mineral product layer until the desired pore fineness is obtained.