Importance

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Abstract

The invention relates to a method for the recovery of secondary polyols from paint sludge coagulate, formed from paint overspray which has first been dewatered by mass action, by chemical treatment in a manner such that the recovered product can be reused in the manufacture of paints. According to the recovery method, the organic components contained in the paint coagulate are glycolytically split at an elevated temperature into reusable polyols. Preferably, a mixture of different glycols is used, preferably in an amount of about 20 to 50% by weight based on the dewatered paint coagulate. The addition of glycol dilutes the paint coagulate and makes it flowable. The water contained in the paint coagulate is evaporated and removed during the glycolytic splitting because of the increase in temperature. The impurities contained in the paint coagulate, such as pigments, coagulants or flocculants, can be comminuted and finely dispersed by intensive shearing of the paint coagulate. At the end of the process, these impurities can also be filtered out from the polyols formed.

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First Claim