Rubber Silica

Since the 1940s, research had been conducted on silica as a substitute for carbon black as an active filler for tires. The success story began in March 1951 when chemist Dr. Hans Verbeek (1908 – 1996) and his laboratory assistant, Peter Nauroth, created precipitated silica for the first time. The new reinforcing filler was initially named Ultra-Siltec VN.

From 1953 on, the product was sold as ULTRASIL® VN 3 – with the initials of the two inventors also incorporated in the brand name, while the number 3 refers to the month of March. Within just a few years, it started to substitute the filler carbon black and made the creation of colored rubber compounds possible.

Sports footwear paved the way for the development of today’s high-performance tires. After all, ULTRASIL® VN 3 initially proved itself in pale and colored shoe soles that no longer left black marks on the floor.

In the early 1970s, tire manufacturers began testing the first versions of super-wet-grip winter tires that used silica as active reinforcing filler. The aim was to replace spiked tires that cause significant damage to the road; however, as the technology was not mature and the results did not meet expectations, research on these early models was stopped.

1972/73: Silica/Silane system

Our silanes are key to the development of modern high-performance tires, as these components enable hydrophilic silica to be chemically coupled to the rubber polymer. Degussa (later Evonik) made the first lab syntheses with the coupling reagent Si 69® in 1971. The Silica/Silane system revolutionized the tire industry. Silica/Silane system is the benchmark for passenger car tire tread performance, i. e. to reduce the rolling resistance and improve the wet traction behavior.

Even today, Evonik is the only chemical company in the world that manufactures both silica and silanes – and has the research expertise required to continue developing these products so that they are ideally matched to each other. The tire industry in particular is able to benefit from our vast portfolio of custom fillers for various requirements, such as those used in winter tires with improved traction in rainy, snowy and icy conditions.

In the 1990s, saving energy was a prevalent topic and ULTRASIL® also played a key role here: Using silica as a filler in place of carbon black can lower fuel consumption – and therefore also CO₂ emissions – by up to eight percent.

In 1992, a large tire manufacturer launched its pioneering green tire technology on the market. S-SBR/BR rubber blends combined with highly dispersible silica and silanes form the basis for tires with low rolling resistance, while simultaneously guaranteeing very good traction in rainy, snowy and icy conditions.

Today, almost no tires in Western Europe are manufactured without silica in the tread surface. In some models, the ratio of filler to polymer in the tread surface is even 1:1. And the levels of silica filler will continue to increase. In May 2021, a new EU tire label was launched which has had the effect of increasing competition amongst tire manufacturers, as every one of them is striving to attain best ratings. 

A low rolling resistance is also important when it comes to the success of the switch to green mobility. Due to their batteries, electric vehicles are significantly heavier than vehicles with combustion engines. Currently, the low ranges of 300 to 400 km are a major disadvantage. This makes tires with low rolling resistance even more attractive: the easier the electric car rolls, the further its range will be.