| 摘要 |
This invention relates to a natural oil based poly-urethane dispersion of water-based anionic polyurethane/urea polymer of high molecular weight by forming a water dispersible NCO-terminated polyurethane pre-polymer, consisting essentially of the reaction product of a polyol component and a polyisocyanate component, at a reduced temperature, which is then dispersed in solvent-free water after applying a neutralizing agent, and then reacted with a chain extender. The polyol component used in this invention comprises of a mixture of (a) ricinoleated natural ester based mono blocked polyol; and (c) carboxylic group-containing polyols. The polyisocyanate component used is an aromatic diisocyanate such as an isomer of toluene diicocyanate and/or methylene diphenyl diisocyanate. The dispersion produced as a result of the process described herein is biodegradable in nature and non-plastic. The dispersion is also free of volatile organic chemicals and/or leachable contaminants. On account of the superior characteristics of the dispersion produced in this invention, it can be widely applied in industry for, among others, direct food contact applications. |
