A curing process of bisphenol-A diglycidyl ether using amine-carboxylic acid salts was studied with focusing on its small-volume shrinkage. The characteristic point of the curing process was the initial high-density created by strong interactions between the ionic species such as electro-statistic one and hydrogen-bonding, which disappeared on the consumption of these species by their reactions with the epoxide to give the low-density neutral polymers. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 836-842, 2009