ENVIRONMENT-FRIENDLY PRINTING INK ON POLYESTER FILM FOR PACKAGING APPLICATION

Abstract

In this thesis, the water-based acrylic-co-resins were first synthesized using MMA, BA, AA, and DAAM monomers by solution polymerization in a set of four different formulations by varying the weight % of DAAM, taking the motivation from the literature review. Characterizations result of all formulations for resins were discussed and suitable resin was selected for the preparation of water-based cyan and black ink. Developed WB cyan and black inks had desirable ink properties i.e., particle size of 306nm and 215nm, viscosity value 70cp and 80cp, pH value of 8.5 and 8.2, surface energy of 32 dynes/cm3 and 30 dynes/cm respectively. Further characterization of printed ink film from WB cyan and black inks on corona treated film was performed, pigment particle distribution was found to be homogeneous, and printed in film thickness was found to be approximate 4.6µm, drying of printed ink was also in just 7 and 8 seconds respectively. Adhesion values for cyan and black ink were 70% and 51%, respectively, which needed improvement. Rub resistance and gloss values for both inks were found to be optimum. All the ink and printed ink film properties had optimal values, but both inks showed poor adhesion, which could be increased by adding a suitable cross-linker. Secondly, the adhesion value of developed water-based ink using selected acrylic-co-resin was improved using an ADH crosslinker, DAAM and ADH form a ketone-hydrazide crosslinking, and thus, adhesion values for the synthesized water-based ink increased from 0.1% to 0.3% (weight % of resin) of ADH and then decreases at 0.4% (weight % of resin) as the excessive concentration of ADH will not react with the DAAM molecules and will exist as free molecules, thus crosslinking density will decrease, and adhesion properties will reduce. Four ink were developed using different concentration of ADH (0.1%, 0.2%, 0.3%, and 0.4% of weight of acrylic-co-resin) and all the properties of ink and printed ink film had optimal values, and adhesion was increased from 70% to 95%. Thirdly, DetA (diethanolamine) was used as an alternative neutralizer to ammonia to reduce ammonia's harmful effect on the environment and human health and make the working condition suitable for workers in printing plants. Storage stability also needs to be calculated by observing the change in pH and Viscosity of ink. Storage environment have a tendency to affect the properties of the ink. Here the difference in pH and Viscosity was monitored for 30 days for different formulations of resin and W-IPA solution.