Investigation Of The Hardener With Latent And Rapid Curing Based On Phenol-Amine Salts For Applications To Cyanate Ester Resins

We have developed the curing agents that have good storage stability for cyanate ester resins. It should be noted that these agents can be given rapid and efficient curing at low temperatures around 100 degrees C. Even though the nucleophilicity was reduced by a phenol-amine salts consisting of basic aliphatic amines and weakly acidic phenols, the curing reaction with the cyanate ester occurred immediately. It means that the control of the curing reaction with cyanate esters is not easy due to the equilibrium between phenol and amine. In order to overcome this difficultly cyanate esters reactivity, the molecular motions suppression by polymer was applied in addition to the phenol-amine salts. The effect of the suppression for hardeners was studied in terms of the storage stability and reactivity to cyanate esters. It has been found out that PSM-EPEDA composed of ethylenediamine-epoxy adducts and novolac phenolic resin exhibits a large storage stability against cyanate esters by its effective suppression of molecular motions accompanied with efficient and rapid curing around 100 degrees C.