Solvent drying of cellulose ester membranes
AssigneeE. I. Du Pont de Nemours and Company
InventorPhilip Manos
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Abstract
Process for drying a water-wet permselective cellulose ester membrane by contacting the membrane with a single water replacement liquid and vaporizing the liquid from the membrane.
Claims9
A process for drying water-wet, semipermeable cellulose ester membrane by contacting the membrane at a temperature of about from 0.degree. to 50.degree. C with volatile solvent having a boiling point below about 175.degree. C to substantially completely remove water from the membrane, the volatile solvent (a) being inert to the membrane and the membrane wetting liquid and having (b) a solubility parameter not greater than about 8.4 cal. .sup.1/2 cc..sup.-3/2 and (c) a hydrogen bonding component of the solubility parameter not greater than about 2.5 cal. .sup.1/2 cc..sup.-3/2 ;
- and vaporizing the volatile solvent from the membrane.
Dependencies are inferred from the claim text.