Kontinuierliche Herstellung von thermoplastisch verarbeitbaren Polyurethanen

• Main Authors: BRAEUER, WOLFGANG, PEERLINGS, HENRICUS, HEIDINGSFELD, HERBERT, TRABERT, LUDWIG
• Format: Patent
• Language: German
• Published: 22.04.2004
• Edition: 7
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

Die Erfindung betrifft ein mehrstufiges Verfahren zur kontinuierlichen Herstellung von thermoplastisch verarbeitbaren Polyurethanen mit verbessertem Verarbeitungsverhalten auf Basis verschiedener Polyole. Multistage continuous production of thermoplastically-processable polyurethane elastomers (TPU) with EN ISO 527-3 tensile strength above 30 MPa involves catalytic reaction of an organic polyisocyanate with a first polyol, followed by reaction of the resulting prepolymer with a second polyol, the resulting prepolymer then being reacted in a high-shear high-viscosity reactor with a low molecular polyol chain-extender. Continuous production of thermoplastically-processable polyurethane elastomers (TPU) with EN ISO 527-3 tensile strength above 30 MPa involves (1) reacting an organic polyisocyanate with a polyol (I) with 1.8-3 Zerewitinoff hydrogens and average M n450-10,000; (2) reacting the resulting prepolymer with a different polyol (II) with 1.8-3 Zerewitinoff hydrogens and average M n60-10,000, the polyisocyanate, (I) and (II) having an NCO : reactive groups equivalent ratio of 1.2-10 : 1; and (3) completely reacting this resulting prepolymer in a high-shear high-viscosity reactor with a low molecular polyol (III) chain-extender with 1.8-3 Zerewitinoff hydrogens and average M n60-400, the steps (1) - (3) being in presence of a catalyst and optionally also 0-20 wt.% (based on the TPU) additives and the overall equivalent ratio NCO : reactive groups in steps (1) - (3) being 0.9-1.2 : 1.