High ethanol tolerance and Ca2+ stability polyacrylate latex binder for universal water-based inks constructed by active emulsifier and low acid value alkali soluble resin

Abstract

With the increasingly strict requirements for water-based ink printing quality and the expansion of application scenarios, dryness, adhesion, and levelling property have gradually become the printing industry's focus. This paper successfully synthesized a self-crosslinking polyacrylate latex stabilized by low acid value alkali soluble resins (ASR) and reactive emulsifier by pre-emulsification semi-continuous seed emulsion polymerization. Moreover, polyaryl polyoxyethylene sulfate ammonium salt (MORS-10) was used as an anionic reactive emulsifier, and crosslinking structure was constructed by diacetone acrylamide (DAAM) and adipic acid dihydrazide (ADH). The influence of reactive emulsifiers and low acid value ASR on the properties of polyacrylate latex was studied in detail. Compared to latex stabilized by ASR alone, and latex co-stabilized by ASR and sodium dodecyl sulfate (SDS), the latex stabilized by ASR and MORS-10 has better ethanol and Ca²⁺ stability, in particular, when MORS-10 accounts for 3 % of the monomer and ASR solids, there is no coagulum generated when diluted with anhydrous ethanol at the mass ratio of 1:1, and the resulting coagulum after mixed with 2 % CaCl₂ to 40 % of the latex mass is negligible. Meanwhile, the adhesion of inks made of it all achieves 100 % on biaxially oriented polypropylene (BOPP), polyethylene terephthalate (PET), and aluminum foil. In addition, with the introduction of small molecule emulsifier, the redissolution of the ink is slightly improved, and SDS has a greater impact than MORS-10. The above findings provide a creative design idea and inspiration for the design of water-based ink binders with high stability and strong versatility.