Abstract: Disclosed is an aliphatic polyisocyanate composition, wherein the molar ratio of an iminooxadiazinedione structure to an isocyanurate structure is 0.01-0.8:1, and the molar ratio of an iminooxadiazinedione structure in a polymer larger than three molecules to the iminooxadiazinedione structure in the composition is 0.2-0.8:1. Provided are a method for preparing the aliphatic polyisocyanate composition, and a coating composition. The aliphatic polyisocyanate composition has both a lower viscosity and a better crosslinking property. The composition can significantly reduce the usage amount of a solvent when used in a coating composition, is more environmentally friendly and also has a better paint film property. The preparation method has a simple process and mild conditions, is easy to operate and control, and is suitable for industrial scale production.

Abstract: Preparation method for a polyurethane optical resin and applications thereof. The preparation method for the polyurethane optical resin comprises: a raw material composition comprising isocyanate and a polythiol compound undergoes a polymerization to produce the polyurethane optical resin. The turbidity value of the isocyanate used in the raw material composition is controlled at ?2 NTU. The polyurethane optical resin produced is applicable in manufacturing optical products.