As formulators of coatings, paints and inks explore using more raw materials that address sustainability benefits and reduce environmental impact, they must balance this growing demand for bio-based ingredients with performance needs.
Using bio-based, renewable raw materials (that is, ingredients derived from renewable resources like trees, plants or agricultural waste) in place of fossil-fuel based ingredients can greatly reduce a product’s carbon footprint and improve its sustainability, but can create some issues to consider, such as:
- finding bio-based ingredients that function similarly to traditional ingredients
- the need to consider all components in the system to understand the interactions that may occur by altering its composition
- accounting for the impact changes could have on the suitability of existing dispersants used in formulations
- determining how the processing behavior of the coating could change
The biggest impact on sustainability can be achieved by moving to resins, solvents, and waxes derived from renewables because they make up the largest portion of a formulation. In some cases, formulators can avoid the challenges mentioned above by moving to biologically derived resins or solvents that are chemically the same as fossil-fuel based polymers, and function identically. But in most cases, existing systems have been designed and formulated to work with all components in the formulation. As soon as one or more components are changed, compatibility with the new components can be affected, causing the system’s characteristics to change.
Well Beyond a System Tweak
Altering a coating or ink formulation by switching to one or more bio-based ingredients goes beyond merely tweaking it, and it can become an outright overhaul of the system. When making bio-based changes, the two components that are primarily replaced are the resin and the solvent system.
For resins, compatibility with the color concentrate is key. If the color concentrate is dropped into a new resin system, it will fall apart and could become unstable, leading to a loss of gloss, color strength and hue. Instability can also negatively impact the shelf life of the final product.
On the solvent side, materials are often petrochemical based. Changing to a bio-based solvent could lead to total failure of a system as a result of a change in polarity and a different impurity profile. However, formulators may be able to use bio-based solvents that are chemically the same as the existing solvent, in which case there may be little impact.
Dispersants and Compatibility
Dispersants can play a critical role in these redesigned, bio-based systems. In order to function effectively, the stabilizing chains in dispersants need to be compatible with the new renewable resins and solvents used in the formulations, so if these are different, the dispersant needs to operate across a range of materials. Alternatively, a new dispersant may be required.
Good dispersants enable the properties of the other components to be optimized and properly perform their functions. For example, dispersants enable pigments to deliver their best color, but aren’t providing the color itself. In addition, dispersants enable the resin to deliver optimized gloss or hardness, among other properties. Dispersants themselves can also have bio-based content, but because they are such a small component of an overall formulation (2-4%), their direct contribution to the bio-content is minimal. They can, however, have a much larger impact by enabling bio-based ingredients to be used as a larger portion of the formulation. That means that designing the dispersant to remain compatible with any formulation changes is critical.
Supporting Formulation Shifts for Decades
With decades of expertise in dispersion, an extensive range of dispersants, and the commitment to continue developing new dispersant technologies, Lubrizol can support formulators in overcoming the challenges associated with moving to bio-based components and the formulation shifts that come with them. Through carefully designed dispersants and working in close collaboration with customers to address their issues, Lubrizol’s technical service team can help make the switch to bio-based easier.
Additionally, for formulators seeking dispersants with bio-based content, Lubrizol offers a selection of dispersing agents designed for use in a range of applications which are fully or partially based on raw materials from plant-based sources. One of the newest technologies in this area is Solsperse™ 29000 Hyperdispersant, a 100% active polymeric dispersant with 50-55% bio-based content that will improve pigment dispersion and stability in liquid organic media.
Contact us to learn more about how Lubrizol dispersants can maintain compatibility as formulations change to more bio-based ingredients.
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