A dark-brown, medium viscosity polymethylene polyphenylisocyanate of high reactivity, a total isocyanate content of about 31% and an average functionality(1) of 2.8. The high functionality and viscosity of this makes it useful for the manufacture of PUR and PIR block foam, sandwich panels and PUR and PIR continuous laminates. The high viscosity of it aids in the development of a stable high viscosity mixture required for the production of continuous PUR and PIR foams. The increased functionality promotes improved foam cure, excellent strength properties and better dimensional stabilities.
Manufacture of PUR and PIR blockfoam, sandwich panels and PUR and PIR continuous laminates