Specialty chemicals group LANXESS
AG has developed a polymer additive for plastics and rubber that is now
available for industrial application. These microgels, which consist of nanoscale
organic particles, can be used to improve the material properties of elastomer
and thermoplastic materials.
In the course of the product’s many years of development, the LANXESS
Technical Rubber Products and Rhein Chemie business units have worked together
closely and applied for numerous patents. These cover the processing method,
the use of nanoparticles in rubber mixtures and the impact on thermoplastic
and thermoset polymers. The Technical Rubber Products business unit markets
these nanoscale particles under the registered trademark Nanoprene, while Rhein
Chemie Rheinau GmbH sells the additive under the brand name Micromorph. After
close co-operation between Rhein Chemie company and the Japanese tire manufacturer
Toyo Tire & Rubber Co. Ltd., the first major series application of the rubber
additive is in the production of winter tires. These tires boast excellent dry
and wet road grip, without the tire rubber hardening on contact with snow or
ice.
Tire technology – improved performance
Different Nanoprene grades can be used to satisfy different requirement profiles
for tires (e.g. summer and winter tires) and various tire components (tread,
side wall, carcass, etc.) in line with their glass transition temperature.
The physical properties of rubber give rise to a conflict of objectives –
also known as the magic triangle of tire technology – between certain
parameters of the rubber. For example, improving wet grip in the past was only
achieved at the cost of higher rolling resistance and, therefore, greater fuel
consumption. Using the new nanoparticles as an additive can improve all three
properties of the magic triangle – wet grip, rolling resistance and service
life of tires – without having to make compromises.
In practice, comprehensive tests conducted by LANXESS have shown that using
Nanoprene in summer tires, for example, improves dry road grip by between 10
and 15 percent. What’s more, adding Nanoprene also improves the stiffness
of the tread blocks, which has a positive impact on the cornering properties
under aquaplaning conditions. The abrasion resistance of tire treads containing
Nanoprene is also much higher than those based on standard silica mixtures.
The test results show that Nanoprene increases the service life of tires significantly.
Manufacture and delivery forms
In principle, Nanoprene consists of pre-crosslinked rubber particles that are
manufactured by LANXESS in an innovative patented emulsion process. Different
conditions can be achieved during the synthesis process, e.g. in terms of the
degree of crosslinking (glass transition temperature) or polarity of the particles,
depending on the required application. With particle sizes ranging between 40
and 200 nanometers, Nanoprene has a large specific surface area, which leads
to improved distribution and joining of the silica filler to the polymer matrix.
After the manufacturing process, the rubber additive is available in the usual
delivery forms such as bales, granules, powders, pastes and master batches.
These additives are very similar to many other elastomers in terms of appearance
and consistency, and they can be processed in the usual way. Special processes
ensure that the particles disperse easily when used by customers.
Posted August 10th, 2009
|
