New portfolio for a new era

It is now more than 40 years, since the first VESTOPLAST® product grades, used mainly in bitumen and asphalt applications, were launched on the market. Thanks to a new catalyst system, it is now possible to produce new grades of this amorphous poly(alpha-olefin) with superior properties. For this achievement the development team, from the Coating & Adhesive Resins and Catalysts Business Lines, has been nominated for the 2019 Evonik Innovation Award.

The application areas of VESTOPLAST® are diverse; it is used for bonding in diapers and carpets, and some of the hot melt adhesives are also used in furniture production. To produce these co- and terpolymers based on ethylene, propylene, and 1-butylene, Evonik relies on Ziegler-Natta catalysts and favors these also for the future.

The two chemists who give this widely used class of catalysts its name received the 1963 Nobel Prize in Chemistry for their work. But the world has since changed—and requirements on hot melt adhesives have increased. In a joint project, researchers from the Coating & Adhesive Resins and Catalysts Business Lines have therefore further developed what lies at the heart of VESTOPLAST® production: the catalyst system, which has been used virtually unchanged since production was first started. Using the RACEbox, a screening tool developed in-house, they searched for a Ziegler-Natta catalyst of the latest generation that could be used to produce new VESTOPLAST® product grades with superior properties—and found one!

In mid-2016, as a first step, a new catalyst system was successfully introduced in production, and selected customers were supplied with samples of the first new VESTOPLAST® product grades. Their feedback was overwhelmingly positive: They attested to significant improvements in quality and superior technical properties in the new material. Many of them were able to use VESTOPLAST® in new products or applications. Particularly advantageous is the fact that they are able to process the new VESTOPLAST® grades as a drop-in solution with existing equipment, which eases the changeover.

Some of the new product grades of the poly(alpha olefin) are now regularly available on the market with capacities of more than 1,000 metric tons. The next innovation steps for VESTOPLAST® are already planned. An additional catalyst system is to be introduced in the next year, and further newly developed product grades are expected to be launched on the market. An important aspect of the work is to address some entirely new applications outside of the traditional hot melt market. Currently, for example, topics in the areas of the circular economy, thermoplastic composites, and polymer additives are being evaluated, to set up VESTOPLAST® sustainably for the next 40 years.