COMPOSITION AND METHOD FOR MAKING POROUS POLYVINYLFORMAL-BASED FILTER Russian patent published in 2014 - IPC B01D39/00 C08L29/04 

FIELD: process engineering.

SUBSTANCE: invention relates to production of porous polyvinylformal-based filters for removal water, impurities and biological contaminants from fluids and gases. Proposed method consists in chemical modification of the following composition containing in wt %: polyvinyl alcohol - 50-20, pore-forming agent - 2-30, cross-linking agent - 2-15, catalyst - 3-15, water making the rest. This is effected by dissolving water-soluble preset-amount polyvinyl alcohol inorganic slat in aqueous solution at heating it to 75-95°C and continuous mixing. Plus adding preset amount of cross-linking agent thereto and mixing for 10-30 minutes. Plus adding preset amount of catalyst at 30-40°C to convert soluble salt into insoluble one and mixing for 10-20 minutes. Plus pouring produced reaction mix into moulds to be held in oven at 55-80°C for 5-20 hours. Now, produced element is extracted from the mould and cleaned of catalyst and pore-forming agent. Finally, it is dried, first, at 15-25°C for 24-48 h and, then, at 30-50°C to constant current.

EFFECT: efficient filter.

7 cl, 1 tbl, 3 ex