PRODUCTION OF HOMOGENEOUS THERMOPLASTIC POLYURETHANE

• Main Authors: KOGAME KUNIO, GOTO NOBUTAKA, YAMASHITA SADAO
• Format: Patent
• Language: English
• Published: 23.01.1987
• 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

PURPOSE:To obtain the titled polyurethane containing a small amount of gelatinous material mass with a small variation range of melt viscosity, by reacting a high polymer diol having a specific molecular weight and low-molecular diol with an organic diisocyanate continuously in an extruder while adjusting the molar ratio thereof. CONSTITUTION:A high-polymer diol having 500-3,000 average molecular weight and low-molecular diol having <500 molecular weigth are respectively melted and stored in storage tanks 1 and 2, and continuously fed to a storage tank 3, mixed and fed from a raw material feed port 9 to an extruder 10. On the other hand, an organic diisocyanate is fed from a storage tank 4 to a raw material feed port 9', mixed with the diols with a screw 12 in the extruder 10, stirred, controlled and reacted by adjusting the variation of the melt viscosity of the formed polyurethane within R(1+ or -2/1,000) range (R is the molar ratio of the total NCO groups to the total hydroxyl groups in the charged raw materials). The resultant formed polyurethane is then filtered through a filter 13 to remove gelatinous materials and the resultant polyurethane is extruded through a die 15 to afford the aimd polymer.