(Hexamethylene diisocyanate (HDI)+Diphenylmethane diisocyanate (MDI)+Toluene diisocyanate (TDI)+Phthalic anhydride)
(hexamethylene diisocyanate (hdi)+diphenylmethane diisocyanate (mdi)+toluene diisocyanate (tdi)+phthalic anhydride)