Calling VP Si 363!

New Degussa Product: a Further Development of Silica-Silane Technology and a Weapon to Help Combat Climate Change

For many decades now, carbon blacks, which are customized industrial blacks, have been the secret stars of tire production. They allow desired new properties to be generated within the bounds of the "magic triangle" of (wet) grip, abrasion resistance, and rolling resistance. The early 1990s saw the advent of a new component heralding the spectacular progression of silica. With the help of organosilanes (bifunctional organic silicon compounds) it became possible to chemically "couple" rubber and silica, and a new star was born: silica-silane technology, also known as “green tire” technology. Today, nearly all car tires in Europe are equipped with treads consisting of such materials. These tires save on gas, are as durable as the older versions, and have significantly better grip, particularly in wet conditions. A disadvantage here is that the use of triethoxysilanes in the tire manufacturing process produces volatile organic compounds (VOCs) that are environmentally harmful.

VOC reduced by more than 80 percent

But there's help at hand, in the form of a brand new organosilane that allows novel reinforcing fillers to couple more effectively in rubber compounds. This rubber silane has been developed by Degussa, the specialty chemicals group that is a wholly owned subsidiary of Essen-based RAG. It carries the name VP Si 363, and is a logical successor to a classic of silica-silane technology, the organosilane once marketed—also by Degussa—as Si 69®. Using VP Si 363 reduces VOC emissions by more than 80 percent during the manufacturing process, so costly waste gas treatment is no longer necessary. This not only saves costs for tire producers but also allows them to satisfy the stricter ecological and economic requirements.

The Kyoto Protocol and the European Commission's proposed Euro-5 standard are also based on the assumption of a further reduction in carbon dioxide emissions. The vision of government officials is to have "low-emissions vehicles" or even "zero-emissions vehicles." In the case of passenger vehicles, this could be realized only through lower gas consumption, for which rolling resistance must be significantly reduced. Tests with rubber compound containing VP Si 363 reveal that the rolling resistance is reduced by over 10 percent. When compared with carbon-black filled compounds, the reduction is in the region of 38 percent. And with the new generation of tires, fuel consumption falls by 3 to 8 percent. In other words, with an average mileage of 30,000 kilometers (about 19,000 miles) per year, the cost of a new set of tires will have been recouped within just one year.

Comparable with the introduction of silica technology

Degussa compares the current leap in development with the introduction of silica technology of the 1990s. The technological advantage over competitors is thought to be “significant.” The final tests before industrial-scale production are currently under way. Almost all the major tire manufacturers have been sent samples of VP Si 363. Industry heavyweights plan to launch products on the market by 2008 at the latest.

In view of the high prices of gas, consumers will welcome the new tires. And many government officials all over the world will be convinced that they have come an important step closer to their goal of sustainable minimization of CO2 emissions. EU Industry Commissioner Günter Verheugen sees another possibility in addition to engine technology: “By 2012 emission will have to be limited to a maximum of 120 grams of CO2 per kilometer. This can't be achieved by engine technology alone¬; we'll need a contribution from tires, for example.” Top-of-the-range German cars currently "burn" upward of 180 to 190 grams. The Commission of European Communities is even more specific: In a communication of February 2007 to the Council and the European Parliament, it recommends “introduction of upper limits for rolling resistance of tires.”

Carbon dioxide emissions worldwide are currently of the order of 25 billion metric tons. Very recently, United Nations researchers predicted a climate change for the year 2020. According to UN estimates, the number of passenger and commercial vehicles worldwide will double between 2015 and 2030 to 1.5 billion.

Degussa is among the most important international producers of reinforcing components (which are normally mixed with the rubber in a proportion of about 30 percent) for the tire industry. The company is the only manufacturer worldwide to offer from a single source all the three products important for tire manufacture: rubber silicas, organosilanes, and carbon blacks. Technical service facilities are available across three continents, in Europe, North America, and Asia.