Water-dispersible cationically modified diisocyanates TIb and TId blocked by n-butanol (BAO) and 3,5-dimethylpyrazole (DMP) for cathode electrodepositing (CED) coating curing were synthesized by introducing cationic triethanolamine (TEOA) into isophorone diisocyanate (IPDI). The crosslinkers TIb and TId were characterized with FTIR, gel permeation chromatography, dynamic light scattering for size distribution, differential scanning calorimeter, and thermogravimetry techniques. The emulsion for CED coating made of TIb or TId and cationic acrylic copolymer showed a high stability with narrow particle diameter distribution because of the ionization of the crosslinker. TG and DSC indicated that the deblocking and crosslinking temperatures of TId and TId containing CED film were always lower than the corresponding temperatures of the TIb and TIb containing CED film. With 0.5 wt % of catalyst dibutyltin dilaurate (DBTL) in TId-CED emulsion and cured at 140 degrees C for 40 min, 90% of the gel content in the TId-CED film was realized. Hence, TId can meet the requirement of low-temperature curing for the CED coating. (c) 2007 Wiley Periodicals, Inc.