Polyurethane-containing materials, such as polyurethane-ureas, have been developed as useful polymers in the manufacture of optical articles because of their excellent properties, such as low birefringence, resilience, and chemical and impact resistance. They have been used in mold castings for lenses, glazings, and the like. Urea linkages in the polymers are particularly responsible for the superior thermal and mechanical properties, such as hardness and stiffness. Aromatic polyamines have been used to prepare these urea-functional polymers. However, cost concerns are prompting searches for and development of alternative starting materials. Aliphatic polyamines tend to be highly reactive with isocyanate, making processing very difficult. New reaction methodology is necessary to allow for the use of readily available and inexpensive materials while still providing products with superior properties.
It would be desirable to provide a cost-effective, straightforward method of preparing polyurethane-containing optical articles that demonstrate outstanding properties.
USPTO Backgrounds
USPTO Backgrounds