Cork suberin as an additive in offset lithographic printing inks

Suberin oligomers, isolated from cork (Quercus suber L.), were used as addi tives in 'Waterless' and vegetable-oil ink formulations, in the range of 2- 10% w/w. The rheological behaviour of the suberin oligomers as well as of t he inks, with and without suberin, were investigated as a function of tempe rature. It was shown that the addition of suberin induces a decrease of vis cosity of both inks. The tack of pristine inks, suberin oligomers and their mixtures were determined at different temperatures: the variation of this parameter as a function of time provided information about the drying kinet ics of these formulations. The tack of the 'Waterless' ink was found to inc rease with the introduction of suberin, whereas that of vegetable-oil based counterparts decreased. All the trends observed were interpreted in terms of the differences in composition between the two types of inks. Preliminar y printing tests were carried out with the various suberin-containing inks. (C) 2000 Elsevier Science B.V. All rights reserved.