Robustness of surfactant-laden latex films

Despite the growing popularity of latex inks in the inkjet printing industry, little is known about the influence of additives present in the ink mixtures on the robustness of the latex films. Scientists have now investigated the influence of a non-ionic surfactant, Dynol 607, on the abrasion robustness of a water-based latex film. For fixation temperature below the minimal film formation temperature (MFFT), they observed an improvement of robustness of the film with increasing surfactant concentration due to the improved film coalescence. However, for temperatures exceeding the MFFT, Dynol clearly has a negative impact on the abrasion robustness.

Robustness of latex films is affected by surfactant in various ways

The surfactant forms ultra-thin surfactant layers at the top of the latex film. These layers can increase the adhesion between the film and abrasive material leading to decreased abrasion robustness. However, other effects such as: macroscopic corrugation of the film or the surfactant layer between latex film and the substrate that may have influence on the mechanical performance of the film, were also identified. According to the researchers, the study shows that mechanical robustness of latex films is affected by surfactant in various ways, which are poorly understood, even though surfactants are commonly used in latex ink formulations.

The study has been published in Progress in Organic Coatings, Volume 160, November 2021.