Bill Tindall, E.Tn.
This stuff seems to be a 2 part finishing system. One part, the resin, is missing from the link you provided. There will be a resin, the film former. This component is not part of the MSDS you linked to. The second component is the crosslinker, the diisocyanate, described in the MSDS. When mixed the diisocyanate reacts with the resin to cross link it. The details of how this chemistry is initiated is not explained on your post. Can A and can B of this stuff? But how mixed?
Diisocyanates are highly reactive. That means they react with almost anything- finish resin, DNA, most every component of a cell, skin, etc. To make them safer the isocyanate is created on each end of a big non-volatile molecule that won't create much vapor pressure to create a breathing hazard from the vapors. But the aerosol is at least a sensitizer and may be deadly if enough is inhaled.