An epoxy resin (NPES-904, epoxy equivalent weight is 815) with a repeating unit, n > 4 was selected as a polymer backbone of polymeric dye. Water-reducible epoxy resin was prepared by a semiesterification of its secondary hydroxy group with succinic anhydride and then dispersed to aqueous phase after it was neutralized with triethylamine. An aqueous polymeric dye was obtained from a ring opening reaction of that epoxy resin with amino group of a direct dye (soluble dye such as C. I. Acid Blue 62, C. I. Direct Orange 39 or C. I. Direct Red 2). These aqueous polymeric dye dispersions carried the average particle sizes between 50 and 90 nm. A polyaziridine was added as a latent curing agent and forming a self-curable system of aqueous polymeric dye solution, which was stable in aqueous phase when its pH remained above 8.0. This aqueous polymeric dye was self-cured on drying at ambient temperature and results in the formation of waterproof and solvent-resistant polymeric dye. These self-curable polymeric dyes had potential for jet ink printing and dyeing applications.
Journal of Applied Polymer Science 100(3), pp.1919-1931