As liquid as oil
Dramatic reduction in the viscosity of HNBR rubbers
Online PR News – 17-September-2009 – – Mumbai, September 17th – Specialty chemicals group LANXESS AG is expanding its portfolio of high-performance HNBR elastomers with a particularly easy-flowing grade. The hallmark of this new addition to the product range – Therban AT 3400 VP – is its viscosity of between 100 and 1,000 Pas (Pascal seconds) at conventional processing temperatures. This means it flows 1,000 to 10,000 times more easily than existing grades with Mooney viscosities of around 39 MU (MU = Mooney Units). The new ultra-low viscous (ULV) Therban has potential applications in liquid injection molding (LIM), the production of in-place gaskets (IPG) and the manufacture of particularly soft seals that achieve a hardness of under 40 Shore A without the addition of plasticizers. This HNBR elastomer, too, is distinguished by its exceptional dynamic properties and very good resistance to aging – both these qualities are valued highly by users of vulcanizates made of existing grades of Therban.
“Since the end of the 1970s, the hydrogenated nitrile rubber Therban has been bridging the gap between nitrile rubbers and fluororubbers such as Levatherm F”, says Dr. Matthias Soddemann, a Therban expert at LANXESS. “Due to its saturated molecular backbone, the HNBR elastomer is extraordinarily resistant to aging and chemicals and, thanks to its polarity, its oil resistance is equal to that of nitrile rubber. Although fluororubbers are distinguished by an even greater resistance to heat, Therban is more cost-effective and demonstrates better dynamic properties.” Recently, LANXESS has been undertaking ongoing development of this material. Examples of its latest successes include fully hydrogenated special grades with high nitrile content for contact with biodiesel and ethanol (ultra-high ACN Therban), and easy-flowing grades marketed under the name Therban AT. “When manufacturing these materials, we apply licensed state-of-the-art technology that Yves Chauvin, Robert H. Grubbs and Richard R. Schrock were awarded with the Nobel Prize in chemistry in 2005”, continues Soddemann. “Even very early on, it was clear to us that the potential of this technology was by no means exhausted with the development of the existing AT grades. In principle, it should be possible to develop grades with a viscosity similar to that of honey.”
Initially being manufactured by LANXESS as a trial product for sampling purposes, ULV Therban AT 3400 VP matches this description nicely. “Even the existing grades of Therban AT make it easier to process our HNBR elastomer more efficiently”, says Soddemann. “As large-volume molds can be filled more quickly, there is no need for the many flow additives that were often used previously. This system is also reliable when it comes to reaching even the most awkward corners of more intricate shapes. With our ultra-low viscous Therban, we are taking the AT concept to new heights – at typical processing temperatures of between 50 and 100 °C, ULV Therban AT 3400 VP is as liquid as oil.”
The new grade expands the potential of the existing AT grades with which it can be mixed very easily in order to reduce viscosity. But that’s not all – thanks to its extremely low viscosity, the HNBR material is also able to move into brand new areas of application, such as fuel cells and energy storage systems in the energy technology sector. Injection molding applications are just one of a very wide range of possibilities. “For the first time, it is now possible, for example, to apply resilient and highly oil-resistant Therban cords to complex molded sheets and plastic components. In continuous use at temperatures of between -40 and 160 °C, they then function as reliable seals”, explains Dr. Günther Weymans, head of the Technical Rubber Products business unit at LANXESS. “Until now, this role was often fulfilled by fluorinated silicones, but these were less able to cope with dynamic loads and were also considerably more expensive. With our new Therban grade, we are filling yet another important gap in the synthetic rubber market. In doing so, we are underlining our commitment to putting our decades of experience to good use by continuing to explore new potential for this important class of materials – one hundred years after the discovery of the first synthetic rubber.” One additional advantage of this Therban grade is its low level of permeation by gases and liquids. Other potential applications include elastic seals that demonstrate low hardness without the use of plasticizers. “The sheer range of possible applications for this new high-performance elastomer is really quite extraordinary, even for a high-end rubber”, adds Weymans, emphasizing the full potential of this development. “We are taking rubber to a whole new level – and one of our main reasons for doing so is to give our customers that all-important edge over the competition.”
LANXESS is a leading specialty chemicals company with sales of EUR 6.58 billion in 2008 and currently 14,335 employees in 23 countries. The company is represented at 46 production sites worldwide. The core business of LANXESS is the development, manufacturing and marketing of plastics, rubber, intermediates and specialty chemicals.
Leverkusen, September 11, 2009
This news release may contain forward-looking statements based on current assumptions and forecasts made by LANXESS AG management. Various known and unknown risks, uncertainties and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. The company assumes no liability whatsoever to update these forward-looking statements or to conform them to future events or developments.
Information for editors:
100 years of synthetic rubber – interesting information about the anniversary and the numerous application areas of the elastic all-rounder can be found at http://www.worldrubberday.com/.
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