Testing the Effect of Dispersants on the Storage Stability of Water-Based Inkjet Inks

Anjeka Experimental Report

(No.: 2025051003)

Testing the Effect of Dispersants on the Storage Stability of Water-Based Inkjet Inks

Experiment Item: Testing the Storage Stability of Water-Based Inkjet Inks

Experiment Category: Dispersant Testing

Experimenter: Shan Chen, Technical Department

Submission Date: May 15, 2025

Abstract

Water-based inkjet inks were prepared using Anjikang dispersants. The stability of the inks was evaluated by measuring the particle size and viscosity of the colorant in the inks, as well as the particle size, viscosity, and centrifugal color development after thermal storage. The experimental results indicate that the water-based inkjet ink prepared with Anjeka 6612 dispersant exhibits the best storage stability.

Keywords: dispersant; particle size; viscosity

1. Experimental Objective

To prepare inks using Anjeka dispersants for dye dispersion, and to evaluate the stability of the prepared inks by testing particle size, viscosity, filtration residue, and centrifugal color development.

2. Experimental Protocol

Materials:
Dyes (60 Red, 54 Yellow, 360 Blue), Anjeka dispersants, purified water, co-solvent, wetting agent.

Instruments:
Nano bead mill, high-speed disperser, nanoparticle size analyzer, rotational digital viscometer, oven, centrifuge, filtration equipment (Büchner funnel, vacuum pump).

Preparation of Dye Paste:
Purified water, co-solvent, wetting agent, and dispersant were mixed in a certain proportion until homogeneous. The dye was then added and dispersed uniformly, followed by grinding using a nano bead mill.

Preparation of Ink:
Purified water, co-solvent, wetting agent, and the dye paste were mixed in a certain proportion until homogeneous, followed by dispersion using a high-speed disperser.

Thermal Storage:
The inks were stored in an oven at 60°C for 14 days.

Particle Size Measurement:
The ground slurry was diluted 10,000 times with purified water. The particle size distribution of the dye in the diluted ink was measured using a nanoparticle size analyzer.

Viscosity Measurement:
The viscosity of the inks was measured at 25°C using a rotational viscometer.

Filtration Test:
A 1 μm pore size filter membrane was placed tightly on a Büchner funnel, and vacuum filtration was performed. Residue on the filter membrane was observed.

Centrifugation Test:
The inks were centrifuged at 3000 rpm for 30 minutes, and the color development difference between the upper and lower layers was compared.

3. Experimental Formulations and Methods

Table 1. Dye Paste Formulation

The dye paste was prepared according to the formulation in Table 1 above and ground using a nano bead mill at 2800 rpm for 6 hours.

Table 2. Ink Formulation

The inks were prepared according to the formulation in Table 2 above and dispersed using a high-speed disperser at 1000 rpm for 10 minutes.

3.1.1 Experimental Results and Discussion
Particle Size Distribution Comparison of Dye Pastes

As shown in the table above, the particle size of the dye pastes prepared with Anjeka 6612 showed almost no change before and after thermal storage.

Particle Size Distribution Comparison of Inks

As shown in the table above, the particle size of the inks prepared with Anjeka 6612 showed almost no change before and after thermal storage.

Ink Viscosity Comparison During Storage

As shown in the table above, the viscosity of the inks prepared with Anjeka 6612 showed little change before and after thermal storage.

Filtration Test

100 g of ink was poured into a Büchner funnel and vacuum filtration was performed. The time required for the funnel to run dry was recorded.

The ink exhibited a fast filtration rate after thermal storage, and no residue was observed on the filter membrane following filtration. This indicates that no flocculation or agglomeration leading to the formation of large particles occurred in the ink.
 

After the inks were subjected to thermal storage at 60°C for 14 days and then centrifuged at 3000 rpm for 30 minutes, the color development of the upper layer and the bottom layer was consistent, indicating that the inks did not stratify.