Silanes used in the rubber industry are generally bifunctional organic silicon compounds with two reactive groups. They are used in high-quality rubber compounds together with silanol group-carrying fillers and are especially effective in combination with reinforcing precipitated silicas.
As opposed to mixtures containing only carbon black fillers, the use of precipitated silicas without silane additives produces improved dynamic properties; however, mixture viscosity, vulcanization time and cross linking density all suffer. Organosilanes, on the other hand, help the silica to bond to the polymer, improve processability and produce very good static and dynamic rubber technological properties.
Evonik Degussa GmbH has been active in the field of sulfur-functional organosilanes since the early 1970s. The first and still most important of these products Si 69® was developed as far back as 1971. It was first used in adhesive mixtures for steel reinforced conveyor belts and soon proved to be eminently suitable for a range of other applications. In particular, the manufacture of tires was revolutionized by the introduction of silica/silane technology. The three important properties such as rolling resistance, improved wet grip and abrasion resistance, which in conventional systems of the past could each be optimized only conditionally and to the diminishment of the remaining properties, could now be comprehensively improved. The new generation of “silica tires” has a significantly improved level of performance in all important properties. In the history of tire manufacture, the only other comparable development leap was the invention of the radial tire. In the meantime, thanks to further processing advances in tire manufacturing, the new generation of disulfanes the most important representative being Si 75®has developed beyond the tetrasulfidic Si 69® and has asserted itself in the tire industry.
Our new development, VP Si 363, is an innovative silane designed specifically for tire manufacturers to improve key tire performance characteristics. Tires made using VP Si 363 provide a reduced rolling resistance and lower fuel consumption by up to 8% over conventional types.
Moreover we have added some experimental products, e.g. VP Si 163 and VP Si 263, to our program which get very good results in mechanical rubber goods and shoe soles.
All sulfur-functional silanes from Evonik Degussa GmbH are available in liquid form, some are also available as dry blend with carbon black or as a prereacted silica compound (COUPSIL®). Monofunctional silanes round off the product range due to their hydrophobising properties, these facilitate processing with mixtures containing silica.
Our Division Aerosil & Silanes also supplies a wide range of chlorosilanes and other organosilanes for applications outside the rubber industry, also under the roof of Evonik Degussa GmbH .
Evonik Degussa GmbH produces silanes at four locations in western Europe, the US and China.