Aqueous inkjet inks and uses thereof

Abstract

The present invention provides an aqueous ink comprising one or more film formers wherein the assembly film concentration in the aqueous ink is from 0.1 to 30 wt.%, and optionally one or more emulsifiers, preferably wherein the total emulsifier concentration in the aqueous ink is from 0.1 to 10 wt.%. The one or more emulsifiers, if any, are fatty acid esters of polyalkoxylated sorbitan, and / or the one or more film formers satisfy at least one of the following properties: a Young's modulus of at least 2 GPa, and a nanohardness of at least 0.08 GPa. Also provided is the use thereof for inkjet printing, preferably on corrugated cardboards or on liners used for producing corrugated cardboards.

Description

technical field [0001] The present application relates to the field of inks for ink jet printing. Background technique [0002] Corrugated board is produced by gluing at least one corrugated paper sheet and one or two flat paper sheets. Corrugated board can be produced using up to seven paper sheets (resulting in so-called triple-layer corrugated board). Corrugated board is generally characterized by the following most critical properties: Lightweight paper achieves extraordinary stability / rigidity when corrugated and bonded to flat paper, resulting in a hollow structure. In this way, stable, lightweight materials made of paper can be produced for various applications, especially packaging applications. [0003] Today, corrugated cardboard is used as packaging material in different fields. In addition to the packaging of different commodities, primary or secondary packaging is the main use of corrugated cardboard. [0004] A major portion of corrugated cardboard for pack...

AI Technical Summary

Problems solved by technology

When prior art inkjet inks are set to have low static surface tension (e.g. 25°C When measured at 23-30mN / m), it is observed that the surface tension of the ink gradually increases with time, resulting in changes in the wetting properties of the ink on the substrate and the instability of the ink

Ink instability can cause serious damage to the press, especially the printhead and ink supply system

The reason for the instability of the static surface tension required for ink compositions during storage or continuous recycling is not fully understood, but is believed to be due to modified, especially polyether-modified polysiloxanes in slightly alkaline aqueous solutions caused by poor long-term stability of polyether-modified polysiloxanes, or due to the adsorption of polyether-modified polysiloxanes to the pigment surface, polysiloxanes cannot be used as free surfactants for the required substrate wetting

[0027] On the other hand, prints obtained from aqueous inkjet inks in corrugators have poor abrasion resistance due to the removal of applied prints (e.g. primers, color Inks, clear inks (varnishes), through abrasion), resulting in unacceptable / poor image quality, or even worse, corrugator stoppages due to jamming, so cannot be used for in-line digital printing in corrugators or in corrugated board lines application

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