METHOD FOR PRODUCING AQUEOUS POLYURETHANE DISPERSIONS BY MEANS OF FLASH EVAPORATION

• Main Authors: ORSCHEL, MATTHIAS, SASSE, WOLFGANG
• Format: Patent
• Language: English; French; German
• Published: 23.07.2008
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

The invention relates to a novel method for producing aqueous polyurethane dispersions from aqueous polyurethane dispersions or solutions containing solvents, by means of flash evaporation of the organic solvent or organic solvent mixtures. The invention also relates to a method for producing aqueous polyurethane dispersions by transforming hydrophilically modified NCO prepolymers or polyurethanes in an optionally aqueous organic solvent or solvent mixture into an aqueous dispersion or aqueous solution, and then removing the same from the organic solvent or solvent mixture.