Interview: “The high pH approach is not suitable for some water-borne coatings“

What significant developments do you expect in water-based coatings until 2030?

Thomas Bernhofer: Synthomer is active in binder technology for water-borne coatings in the segments architectural coatings (interior and exterior wallpaints, trim-paints) and industrial coatings (wood and metal). We expect a significant growth in these segments to 2030 driven by following global trends: VOC reduction: Although some VOC reduction has been achieved in the past, mainly through solvent-free interior paints, the trend towards lower VOCs continues. This is being addressed by low MFFT binders, even in applications where higher hardness and blocking resistance are required. To achieve the somewhat contradictory properties of low MFFT with high hardness, multi-phase binders and crosslinking are the preferred options.

Improved functionalities: The demands on the property profile of water-borne binders are increasing. We are addressing this with improved functionalities in mechanical properties (higher hardness, resistance), chemical resistance ( stain and dirt pick up resistance) and ease of application (longer open time and extended application window).

Sustainability: The market is demanding binders with a reduced Product Carbon Footprint (PCF) and we currently offer ISCC+ certified mass balance (bio, bio-circular and circular) products to enable our customers to take advantage of biogenic carbon and the resulting reduction in carbon footprint. In addition, we offer partially C14 renewable raw materials, as well as extended service life for exterior coatings through improved durability, which helps to reduce the carbon footprint of products. We are also seeing increasing demand for the replacement of solventborne coatings with water-borne coatings, as this reduces our customers’ carbon footprint from the VOCs in solvent systems.

What regulatory obstacles and external factors might accelerate the advancement of water-based systems?

Bernhofer: The most significant impact in terms of regulatory barriers is in the area of biocides (BPR). In our view, the availability of reliable, long lasting in-can preservation is key for water-borne coatings. Unfortunately, the high pH approach known from the wall paints segment is not suitable for some water-borne coatings, e.g. waterborne trim paints. More recently, other classes of raw materials for waterborne coatings have come into focus, such as coalescents (e.g. butyl glycol) or additives (e.g. PFAS and DPOS). Some cross-linking agents such as benzophenone, isocyanates and ADH are also being restricted. Eliminating or replacing raw materials requires a lot of reformulation work on the customer’s side, and worse, the replacements do not always have the same performance.
On the other hand, any further regulatory restrictions on VOCs in general or on the use of solvent-based products by professionals only could accelerate progress.
External factors that could accelerate the development of water-borne systems are the availability of renewable C14-based raw materials in sufficient quantities and at affordable prices.

Event tip

Thomas Bernhofer will speak at the EC Conference Bio-based & Water-based Coatings 2024. Discover the future of sustainable coatings at the event in Cologne, Germany, on November 5th – 6th, 2024! Join leading experts to explore the latest trends and innovations in water-based and bio-based coatings.

Reading tip

This interview is part of our “Expert Voice” section in the European Coatings Journal. You can read the other expert interview with David Dominguez, Strategic Planning Director at Briolf, here.