50 years of HDI hexamethylene diisocyanate production by Bayer MaterialScience
Bayer MaterialScience, which will operate under the new name Covestro from September 1, is celebrating a major anniversary: 50 years of hexamethylene diisocyanate (HDI) production in Leverkusen. Today, the site is home to the world’s largest production facility for this coating raw material and the company’s other coating polyisocyanates. HDI from Leverkusen is used primarily for high-quality automotive and industrial coatings. They protect car bodywork and the cars of Germany’s ICE high-speed trains, and can withstand even the harsh climate conditions to which aircraft such as the Airbus A380 are subjected
“As mobility increases, this calls for high-performance and durable coatings that are also environmentally friendly,” said Daniel Meyer, Head of the Coatings, Adhesives, Specialties Business Unit at Bayer MaterialScience and Covestro. “Polyurethane coatings fulfil these requirements precisely and have established a firm place, particularly in glossy topcoats.”
Thanks to their good weathering, abrasion and impact resistance, polyurethane coatings can be found in many different applications. Thus it is no surprise that demand has continued to rise over the years. “In line with market development, we have repeatedly expanded production in Leverkusen, and have invested over EUR 80 million in new capacities over the last twelve years alone,” Meyer explained.
And the journey continues. At the European Coatings Show 2015, Bayer MaterialScience unveiled two new polyurethane hardeners based on pentamethylene diisocyanate (PDI) and xylylene diisocyanate (XDI), some of which will be produced in Leverkusen by its successor company, Covestro. The PDI product is the first plant-based coating and adhesive hardener, with approximately 70 percent of its carbon content provided by biomass.
XDI was developed for the innovative polyurethane adhesives used in high-performance packaging, among other things. Because the raw material hardens quickly at room temperature, it helps make packaging production more flexible and efficient.
Sustainability and efficiency also play an important role in the manufacturing of coating raw materials at Bayer MaterialScience. One example is the gas phase technology designed in Leverkusen. It was originally developed for HDI production and helps to considerably reduce energy and solvent consumption. “By investing in cutting-edge technologies and expanding capacities, we are further boosting the competitiveness of the Leverkusen site and will thus continue to safeguard jobs in the region also in the future,” said NRW site manager Klaus Jaeger.
The HDI story began back in 1958, when Kuno Wagner, who was employed by Bayer AG at the time, laid the foundation for an unparalleled success story with the first patents for the production of HDI derivatives. An HDI variant with the brand name Desmodur® N quickly became the key product among the well-known DD coatings. The acronym stands for the two main components Desmodur® and Desmophen®, which are stored separately and then mixed immediately before the coating is applied.
Two-component polyurethane coatings unleashed a completely new degree of freedom. They cure at room temperature, and the coating applicator can modify the curing time to suit the application in question, only mixing the coating as and when it is needed. DD coatings quickly caught on for use in many applications. The main aim of later developments was to reduce the solvent content.
The new company Covestro will continue this pioneering line of work with ongoing further development of HDI derivatives to meet changing market requirements in the coatings field and by tapping into new applications. Covestro will also be working on an expanded isocyanate portfolio incorporating PDI and XDI.