Water-Based Anionic Polycarbodiimide Crosslinker for Coating

Water-based anionic polycarbodiimide crosslinker which the storage stability is more than 6 months was synthesized by isophorone diisocyanate(IPDI), sodium hydroxyethyl sulfonate(SHES), 3-methyl-1-phenyl-2-phosopholene-1-oxide(MPPO). Polycarbodiimide crosslinker was characterized by Fourier transform infrared spectroscopy (FTIR) and was applied to aqueous polyurethane resin coating agents which containing carboxyl groups. The mechanical properties, the swelling ratio of the film in water, 0.05mol/L Sodium hydroxyl and butyl acetate and the dry and wet rub and abrasion resistance were tested. The infrared spectrogram shows the characteristic peak of -N=C=N- appeared at 2200～2100cm-1 and the characteristic peak of -SO3-appeared at 1105cm-1.The results of application indicated that: WAPC was applied to polyurethane resin, tensile strength of the film increased from 1.485MPa to 3.752 MPa. The swelling rate in water，0.05mol/L Sodium hydroxyl，butyl acetate decreased from 444.9% to 126.1%，181.9% to 92.5%，351.2% to 186.4% respectively; WPAC was added to top coating of coating agent, it was founded that the dry and wet rub resistance were both increased.