Synergetic effect of cationic starch (ether/ester) and Pluronics for improving inkjet printing quality of office papers

Abstract

Improving the printability of paper is still a relevant challenge, despite the fast development of digital communications.While it is well-known that cationic starches enhance ink density, their commercial paper-grade forms are limited to ethers with low degree of substitution. This work addresses the underexplored potential of highly substituted cationic starch for paper coating and its combination with tri-block polymers, namely Pluronics (P123 and F127), taking advantage of their supramolecular interactions with amylose chains. For that purpose, cationic starch ether and ester (starch betainate), both with a degree of substitution of 0.3, were synthesized by alkaline etherification and by transesterification, respectively. Paper without any surface treatment was subjected to one-side bar coating with suspensions encompassing those products and Pluronics, besides other common components. Black, cyan, yellow and magenta inks were printed on all coated papers through an inkjet printer. Key properties of printing quality such as the gamut area, gamut volume, optical density, print-through, inter-color bleed and circularity were measured in a controlled temperature-humidity environment. For instance, a formulation with cationic starch (ether/ester) and P123 improved the gamut area by 16-18% in comparison to native starch-coated paper sheets. Interestingly, the individual assessment of each component showed that cationic starch ether, starch betainate and P123 only improved the gamut area by 5.6%, 8.9% and 6.8%, respectively. Finally, but not less importantly, starch betainate was found to quench optical brightening agents to a lesser extent than cationic starch ethers.

Micro-/Nanofibrillated Cellulose-Based Coating Formulations: A Solution for Improving Paper Printing Quality

“…It also decreased as the concentration of c-NFC increased. Similar findings were also reported in our prior investigation with the use of cationic starch ether in the coating formulation, as whiteness was reduced with the addition of said cationic starch [19].…”

“…Overall, the printing quality was evaluated as reported elsewhere [19]. Briefly, an inkjet printer (HP Officejet Pro 6230) was used to color-print all coated papers, besides BP as reference.…”

“…Recent research indicates that the use of cationic starch ether/ester in combination with Pluronics improves the inkjet printing quality of office paper, since a positive surface charge exhibits enhanced ink hold properties and establishes synergetic interactions with non-ionic tri-block surfactant polymers. Moreover, the cationic starch ester, SB, has certain advantages over the conventional cationic starch ether, at least in terms of maintaining the whiteness of coated paper in presence of a sulfonated optical brightening agent (OBA) [19]. A hypothesis that is worth considering is whether the direct use on paper of the zwitterionic amino acid used to synthesize SB, i.e., betaine, which is commercially available as betaine hydrochloride (BetHCl), could also attain positive results, saving the costs of the synthesis process.…”

Improving the Barrier Properties of Paper to Moisture, Air, and Grease with Nanocellulose-Based Coating Suspensions

“…Due to the variety of interactions between the very different and many components of multi-purpose formulations ( Multi ), a small amount of the non-ionic surfactant F-127 was added in some cases to ease interfacial compatibility [ 21 , 22 ]. Such amounts accounted for 0.5% of the total solid content for Multi 1 and 2 , 0.0% for Multi 3 , and 2.0% for Multi 4 .…”

Dynamic Penetration Profile of Starch Betainate, Pluronics and PCC Coated Papers

“…Some other factors such as sufficient positive charge on the surface and a more closed surface can also help to improve the printing quality by retaining the ink pigments on the paper surface [2][3][4] . In this sense, starch betainate (a cationic starch ester), Pluronics (triblock co-polymers) and precipitated calcium carbonate (PCC) were identified as good coating components to produce papers with superior printing quality [5,6] . In this study, paper sheets were coated with different concentrations of coating components, namely starch betainate, Pluronics and PCC.…”