Specialty Additives for green tires
The products with “green” potential include Vulcuren®, a crosslinking and anti-reversion agent for the manufacture of eco-friendly tires. It forms much more thermally stable and flexible hybrid network points than “traditional” rubber crosslinking with sulfur bridges. As a result, the rubber retains its elastic properties much longer than conventional systems when exposed to heat. The vulcanization temperature therefore can be increased as needed to significantly boost productivity in the manufacture of large rubber components, such as truck or construction vehicle tires.
Vulcuren® is also an alternative to the secondary accelerator N,N’-diphenylguanidine (DPG), which is widely used to make fuel-saving silica tires, but unsuitable in combination with silanes, such as Si 363. Furthermore, Vulcuren® does not release aniline under vulcanization conditions as DPG does, which is undesirable to many customers. In road tests, Vulcuren® has proven that it counteracts abrasion in truck tires made of NR, BR and SBR rubber grades. Likewise, car tires are less susceptible to use-related aging if made with Vulcuren®.
Another LANXESS innovation for green mobility is the Vulkalink™ line of rubber additives. These help to reduce the rolling resistance of state-of-the-art tread mixes and optimize the behavior of tires in wet conditions. They are brand new additives that significantly improve the interaction between the polymers and the silica filler.
The Vulkalink™ products can very easily be added to the vulcanization process without causing compatibility problems with other “ingredients.” A second group of Vulkalink™ products includes Vulkalink™ 1871, an additive with one big advantage - manufacturers are able to cut the amount of filler without having to modify their production process and with no negative influence to the hardness of the rubber blend. Lowering the added amount of silica greatly improves the rolling resistance of passenger car tires, representing yet another step towards making future mobility one thing above all: more sustainable.
Curing bladders are used in tire manufacturing. Once the press is shut, the unvulcanized tire blank is forced against the internal wall of the mold by internal pressure. This is done using a butyl rubber bladder that is then inflated under high pressure and at high temperatures to give the tire its final shape. LANXESS subsidiary Rhein Chemie Rheinau GmbH makes bladders at three South American locations, then sold under the brand name Rhenoshape®.
The Rhenoshape® curing bladders ensure a smooth and efficient tire curing process. With cost-efficient production, the state-of-art bladders are designed to shorten the cure cycles and increase productivity with high conductive compounds. Due to better tire finish appearance, the innovative bladder venting design and surface finish reduce tire scrap.
The demand for bladders is expected to grow parallel to global tire production, which is expected to increase by five percent annually in the coming years. The megatrend of mobility is underpinning this growth, driven by a growing size of middle-class in countries such as Brazil, China and India.
Aflux® 37 is a processing promoter additive designed to improve processability of green tire compounds including silica & SSBR compounds. It helps to eliminate many of the negative aspects in gaining proper silica dispersion in tire tread compounds.
Aflux® 37 can be used in tires and technical rubber goods containing compounds based on white polar fillers. It enhances the processing of silica-based rubber compounds through the improvement of silica dispersion and the decrease of compound viscosity. It brings faster extrusion rates, thus greatly raising productivity, yet with less energy consumed and less waste generated.
While the economization on production cost constitutes a great strength of Aflux® 37, it is not achieved by compromising the tire performance. The physical properties of tires remain intact as ever. Moreover, it also helps optimize rolling resistance in order to improve fuel efficiency and reduce CO2 emission.