SeaSpen® IN: Sustainable Stabilizer For Coatings & Inks

Inks, paints, and coatings use pigments for aesthetic purposes and to display information on materials. Pigments are large particles that tend to settle with gravity and agglomerate together. This can result in an uneven appearance that may cause surface defects on the material that the coating, paint, or ink is applied to.

In general, a few characteristics determine the settling of particles in a liquid formulation: continuous phase rheology, particle density, and particle size. The density and size of pigment particles cannot be changed. Therefore, a stabilizing rheology-modifying agent must be used in coating, paint, and ink formulations to alter viscosity and provide sedimentation resistance.
 

SeaSpen® IN Stabilizing Agents and Rheology Modifiers

SeaSpen® IN is the ideal long-term stabilizing agent and rheology modifier for water-based coatings, inks, and paints. The three main reasons are presented below.
 

1. Sustainability, Biodegradability, and Solubility

SeaSpen® IN is a bio-based, natural stabilizing agent and rheology modifier based on iota-carrageenan sustainably harvested from red seaweed farms. It is designed to be biodegradable and readily soluble in cold water. This simplifies the blending process, making it compatible with a wide variety of water-based formulations.
 

2. Pigment Stability

Titanium dioxide (TiO2) is one of the most frequently used materials in the creation of coatings and paints. The benefits of using this pigment are the brightness, white coloration, and protection from UV degradation it provides. The drawbacks are the water insolubility and extreme density at around 4 g/cm3, which negatively impact formula stability.

A stability test was prepared using samples with and without SeaSpen® IN to evaluate dispersions for long-lasting properties. The sample with SeaSpen® IN had 0.15% wt stored and aged for two weeks at 54°C. The resulting viscosity was analyzed and noted visually below.
 

On the left, the TiO2 dispersion control developed noteworthy hardening, and at the bottom of the container, a dried layer of pigment formed on the surface that was not redispersible and could not be blended. On the right, the formula with SeaSpen® IN additive maintained stable and homogenous pigment dispersion.

A Turbiscan LAB stability analyzer was used to evaluate the samples at 25°C for long-term stability. A lower Turbiscan Stability Index (TSI) indicates better long-term stability.
 

The control shows increasing TSI values over time. In comparison, the SeaSpen® IN sample resulted in lower TSI values over time. This result shows that the formula with the SeaSpen® additive conclusively increased formula stability.
 

3. Shear-Thinning Rheology

The carrageenan polymer within SeaSpen® IN functions as a stabilizing agent that can form a three-dimensional matrix, which provides associative thickening in water-based formulations.
At low to no shear, SeaSpen® IN imparts high viscosity to formulations. The three-dimensional matrix helps suspend large solid particles, such as fillers and pigments, so they do not settle or agglomerate on any surfaces.

The formula quickly loses viscosity at high shear and quickly recovers when shear is removed. This is called shear-thinning and is significant when developing inks, paints, and coatings. To allow leveling onto substrates and even material spread, lower viscosity is necessary when paints are subjected to high shear during application. After the paint is applied, higher viscosity is necessary to prevent sagging and dripping, particularly for overhead or vertical surfaces.

A three-interval thixotropy test was conducted on the TiO2 dispersion samples to show the thixotropic effect of SeaSpen® IN for paint applications, shown below.

 

At 0.15%, SeaSpen® IN significantly decreased viscosity at high shear. When shear was removed, the sample rapidly increased to approximately the same viscosity as prior to shear. Even at a low use level, SeaSpen® IN demonstrates that thixotropic and shear-thinning rheology can be accomplished, which is important to achieving smooth paint and coating applications.

Summary

SeaSpen® IN is a natural rheology modifier and stabilizing agent. Formulators of water-based coatings, paints, and inks can use this material for long-term stabilization. Harvested from renewable seaweed farms, this carrageenan is sustainable and biodegradable. SeaSpen® IN is exceptionally effective at low use rates as a thickener, emulsion stabilizer, pigment dispersant, and provider of shear-thinning rheology. Click below for more information or to request a sample of SeaSpen® IN for your application.