The wettability effect of branched polyglycerols used as performance additives for water-based printing inks

Abstract

The aim of this work was to study the influence of primary and secondary hydroxyl groups in the branched polyglycerol on the selected properties of water-based printing ink and copies printed with waterbased flexographic printing inks. The branched polyglycerols were synthesized through anionic ring-opening polymerization using trimethylolpropane as a starting material. Obtained polyglycerol exhibited an irregular structure containing primary and secondary or predominantly primary hydroxyl groups in the macromolecule. The analysis (FTIR, 1 H NMR, 13 C NMR) confirmed the structure of polyglycerols. Obtained polyglycerols were then used as a performance additive in a water-based flexographic printing ink. The contact angles of the printing inks on the printing base were measured. The impact of a small amount of branched polyglycerol on the printing ink color was examined by studying the optical density of a full-tone area, the color values (CIELAB), the total color difference DE Ã ab , and gloss of the dried ink film. In general, the addition of branched polyglycerol containing only primary hydroxyl groups improved the wettability of the plastic film and gloss of printing ink with an acceptable total color difference DE Ã ab in contrast to branched polyglycerol with primary and secondary hydroxyl groups.

Surface Properties of Poly(Hydroxyurethane)s Based on Five-Membered Bis-Cyclic Carbonate of Diglycidyl Ether of Bisphenol A

“…Moreover, the absorption of water into the coating was observed, while the water contact angle measurements were performed. This effect was also observed for other NIPU layers [ 14 , 24 , 29 ] and it is directly related to the structure of the PHUs where pendant hydroxyl groups and urethane groups are built into the macromolecule. The pendant hydroxyl group improves the adhesion of PHUs with various substrates and influences the appearance of hydroxyl bonds [ 31 ].…”

“…Furthermore, there is growing attention of researchers concentrated on replacing petroleum-derived chemicals with renewable sources or using less harmful PU, for example as waterborne polyurethane materials instead of solvent-based materials [ 14 , 15 ]. PHUs are not a novel group of polymers; many studies on their synthesis from bio-based renewable sources have already been presented in the literature [ 11 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Additionally, some hybrid PHUs have already been described [ 11 , 26 , 32 , 33 , 34 , 35 ].…”

Usability of cellulose‐based binder in water‐based flexographic ink

“…The obtained Δ E 00 values give the difference between a displayed or printed colour and the original colour [42]. A Δ E 00 value that is low indicates that the difference between the colours is low, and if it is too high indicates a large difference between the colours [43]. The Δ E is measured on a scale from 0 to above 100, the actual upper limit being determined by the reference illuminant.…”

Effects on print quality of varying acrylic binder types in water‐based flexographic ink formulations

“…A low ΔE value indicates that the colours are very close to each other, while a very high value indicates a difference between the colours. 29,30 A ΔE ≤ 1 indicates a colour difference that cannot be perceived by the human eye. A ΔE value between 1 and 2 indicates a colour difference that can only be detected with close observation with a measuring device, ΔE difference between 2 and 3 indicates a colour difference that cannot be easily distinguished from the standard colour by most observers.…”