IT1206427B - Porous support elements for reverse osmosis membranes - comprising cast hollow mouldings of granular filler with solvent-free liq. epoxy binder - Google Patents

Abstract

Supports are made by (A) forming a liq. catalysed mixt. of 100% potential solids comprising (1) 1 pt. liq. epoxy resin, (2) 0.75-1.55 pts. of a liq. organic acid anhydride curing agent, (3) 0.25 - 0.95 pts. of 1 liq. diepoxide diluent and (4) at latent catalyst comprising quaternary ammonium, phosphonium or arsonium salts, whereby the resin has a viscosity of 100 cP at 25 degrees C; (B) mixing the resin compsn. with a granular filler so that the filler particles are coated with the resin, such that the filler constitutes = 1-18 wt.% of the coated filler; (C) casting the fileld resin compsn. into a mould to give a cast structure with >=1 internal cavity; (D) heating the mould to cure the cast material, (E) cooling and removing the porous casting having >=1 axial cavity through it and having a bursting strength of >=17.2 x 105 Pa to water, and (F) casting a semi-permeable reverse osmosis membrane on the internal axial cavities of the moulding. The porous bodies have high strength and are made without the use of solvents which may become trapped in fissures in the prod., as in prior art units of this type. The castings are esp. useful for making appts. for extn. of fresh water from sea water.