Leverkusen, Germany – Buna CB PBR 4076 and PBR 4065 are two new neodymium polybutadiene rubber grades (NdBR) from LANXESS for making particularly fuel-efficient tires. Despite their high molar masses, both these variants are exceptionally easy to process – without any compromises when it comes to their dynamic mechanical properties.
“The higher a tire rubber’s molar mass, the better the product’s end properties normally are – rolling resistance, for instance,” explains Dr. Heike Kloppenburg, an expert on tires and synthetic rubber at LANXESS’ site in Dormagen, Germany. “However, high molar masses normally go hand in hand with high Mooney viscosities, which makes the rubber difficult to process,” she continues.
Although it is possible to solve this problem by slowing down the extrusion process, reducing processing temperatures or adding processing aids, this increases production costs and can have a negative impact on the compound’s end properties. LANXESS’ new NdBR rubber grades can help tackle this challenge. These variants of the LANXESS tire rubber grades Buna CB 24 and Buna CB 22 have been optimized using LANXESS technology with the specific objective of making them easier to process without any compromises in terms of the tires’ end properties. As Kloppenburg explains, “PBR 4076 matches the tire performance of the high-Mooney grade Buna CB 22 but can be processed in the same way as Buna CB 24, which has a far lower viscosity. For example, we have significantly increased the rubber’s tackiness on the roller and have done so without adding any processing aids.” P
BR 4065, on the other hand, is roughly equivalent to Buna CB 24 in terms of performance but is as easy to process as a cobalt-polybutadiene rubber. “In addition to these benefits, both new grades produce the same good rolling resistance values as Buna CB 22 and 24 in the laboratory. This enables tire manufacturers to take their products’ performance to the next level. Companies that previously specialized in processing Buna CB 24 can now make products with the impressive end properties of Buna CB 22 compounds with a comparable outlay,” says Kloppenburg.
Source: Rubber World
