High purity recycling of paints, lacquers or solvents contg. impurity - is by adjusting solid content, sedimenting coarse, particles, basifying supernatant, acidifying, pptn., etc.

摘要

Paints or lacquers or (in)organic solvents contg. some paint or lacquer are worked up by (A) adjusting the solid content of the liqs. to be worked up to 10-20, pref. 15%, (B) allowing coarse particles to sediment and decanting the supernatant, (C) adjusting the pH of the supernatant to about 8 with a lye within 30, pref. 10 mins., (D) adjusting the pH to 5.5-7.5, pref. 6.0 with H3PO4, (E) sepg. the ppte. obtd. in known manner and (F) distilling the soln. left to recover binder. - The lye is pref. aq. NaOH. A flocculating agent such as Al2(SO4)3, FeCl3 and/or a polyelectrolyte is added before or together with the H3PO4.