OFFSET PRINTING INKS BASED ON RAPESEED OIL AND SUNFLOWER OIL .2. VARNISH AND INK FORMULATION

Two sets of variable oil length, alkyd resins modified by sunflower oi l (SOA) and by rapeseed oil (ROA), were evaluated in offset formulatio ns with mineral oils as diluent. The more suitable alkyds for this kin d of application were determined. In a second experiment, hydrocarbon solvents were substituted by the fatty acid methyl esters derived from rapeseed oil or sunflower oil to produce ecologically friendly offset printing inks. Finally, the ROA and the SOA were associated with the methyl esters derived from the same vegetable oil. New properties of t he varnishes composed of a vegetable diluent were evaluated. The quick set formulations with the methyl esters do not need important modifica tions, as opposed to the heatset formulations.