Process for recovering and recycling organic binder components from a coatings slurry

US5281629A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Wieland Hovestadt · Leichlingen, DE
• Lothar Kahl · Bensberg, DE
• Juergen Meixner · Krefeld, DE
• Christian Wamprecht · Neuss, DE
• Volker Schneider · Sinsheim, DE
• Manfred Schoenfelder · Leverkusen, DE

Key dates

• Filing date: Feb 10, 1993
• Grant date: Jan 25, 1994
• Expiry date: Feb 10, 2013

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D7/71
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for recovering and recycling the organic binder components accumulating during the spraying of a solvent-containing, two-component polyurethane coating or a solvent-containing, moisture-curing one-component polyurethane coating by PA1 i) forming a coatings slurry containing the organic binder components, water and a coagulating agent, PA1 ii) mixing the coatings slurry, optionally after removing a portion of the water, with an organic solvent which is inert towards isocyanate groups, PA1 iii) reacting the free isocyanate groups present in the mixture obtained in step (ii) with a compound containing one isocyanate-reactive group which is more reactive with isocyanate groups than both water and the isocyanate-reactive component of the two-component polyurethane coating, if present, and PA1 iv) removing any remaining water and insoluble components from the organic phase accumulating in step (iii) and recovering the organic phase containing the organic binder components.