Model Reaction Studies and Crosslinking of Dimethyl-meta-isopropenylbenzyl Isocyanate Containing Ambient Crosslinkable Latex

The mechanism of TMI-induced crosslinking was studied using model reactions in a mixture of TMI, water and acetic acid. The hydrolysis of TMI was slow at room temperature, but could be enhanced by the incorporation of carboxylic acid groups. The formation of amide linkages via condensation between TMI and carboxylic acid groups did occur at room temperature, but was very slow. The crosslinking of a fully crosslinked latex film was also studied using a new type of latex. The degree of crosslinking of the core-crosslinked latex films was lower than theoretical values and the mechanical properties were poor, which was ascribed to insufficient interfacial crosslinking.