Tailor-made crosslinkers for high performance PUR coatings: Hyperbranched polyisocyanates

摘要: The introduction of Self-Crosslinking Isocyanates (SCI) as AB 2 -building blocks makes it possible to synthesize hydroxyl- or isocyanate-group terminated dendrimers. Furthermore, inherent reactivity differences non equivalent NCO-groups specific diisocyanates (such isophorone diisocyanate [IPDI] toluylene [TDI]) can be used build up hyperbranched polyurethane structures in a one pot synthesis without the need arduous protection/deprotection steps. This synthetic approach allows construction tailor-made molecular architectures which are end-functionalized with either hydroxyl isocyanate groups. These products were then tested crosslinkers 2-component coating formulations where they displayed better hardness than any other aliphatic raw material.