Effect of Printing Ink Binder Composition on Emulsification of Fountain Solutions, 1996 International Printing & Graphic Arts Conference Proceedings
Marie Wickman and Karin Hallstensson
Institute for Surface Chemistry
Göran Strom
Stora Corporate Research AB
This paper discusses the effect of alkyd resin composition on the emulsification of fountain solution into heat-set printing ink oil. Data on interfacial tension and initial droplet size are reported. The initial droplet size of emulsions formed by mixing fountain solution and printing ink oil, containing alkyd resin, is strongly dependent on concentration and type of alkyd resin. Addition of non-ionic surfactant to the aqueous solution decreased the foun-tain solution -oil interfacial tension but had no significant effect on droplet size. Addition of isopropyl alcohol to the aqueous phase resulted in successively smaller droplets. Higher concentrations of isopro-pyl alcohol gave smaller droplets. The interfacial tension between water and alkyd resin-containing oil decreased with alkyd resin concentration and polarity. This suggests that the alkyd resin orients itself at the interface with polar groups in the water and apolar segments in the oil. The alkyd resin then acts as an emulsifier and stabilises the emulsion. KEYWORDS Alkyd resin, Fountain solutions, Offset printing, Emulsions, Interfacial tension, Printing ink,