AMINE-QUINONE POLYURETHANES AS BINDERS FOR METAL-PARTICLE TAPE

Two new polyurethanes were prepared by condensation polymerization from the new diol monomer 2,5-bis(N-2-hydroxyethyl-N-methylamino)-1,4-benzoquinone, AQM-1. One aminequinone polyurethane, AQPU-4, was made from AQM-1, polycaprolactone diol and isophorone di- isocyanate. The other, AQPU-8 was made from AQM-1, poly(l,2-butylene glycol), and tolylene-2,4-diisocyanate. Three different MP formulations were prepared and films cast onto polyester base film by hand draw-down; i) a generic MP formulation containing a commercial polyvinylchloride wetting binder and commercial polyurethane binder, ii) a formulation where the polyvinylchloride was replaced with AQPU-4, and iii) a formulation where the polyvinylchloride was replaced with AQPU-8. In a comparative corrosion study, the samples were soaked in pH 2.00 buffer solution and the degree of corrosion measured. The iron pigments in the generic MP formulation completely corroded after two hours exposure. The formulations containing the amine-quinone binders showed less than 10% corrosion after more than 160 hours exposure.