Therban (HNBR) for Hose Applications
|Date Published||January 1, 2007|
Therban® (Hydrogenated Nitrile Butadiene Rubber) is a high performance specialty elastomer having a combination of unique properties important to hose applications such as: excellent mechanical and dynamic properties, low compression set, retention of properties at elevated temperatures, excellent heat resistance with a service temperature from -40 to 165°C, resistance to ozone, aggressive fluids and oils, abrasion, as well as very good low temperature properties. HNBR is used in a wide variety of demanding hose applications including: power steering, hydraulics, oil coolers, automotive air conditioning, turbo charger, diesel, as well as for the fuel, oil well service, and chemical industries. The paper will also discuss the unique properties of Therban® AT, a portfolio of low Mooney viscosity HNBR grades and their potential use in hose applications. These grades have unprecedented low Mooney viscosity (ML 1+4@100°C approximately 39) combined with a narrower molecular weight distribution which provides optimum mechanical properties. The grades are sulfur- or peroxide-curable and are available in a wide range of acrylonitrile levels for different degrees of oil and fuel resistance. These new products offer all of the advantages of regular HNBR while providing improved processing characteristics: easier mixing, faster extrusion rates, and smoother surfaces/edges of extruded parts. In addition, these grades can be compounded with reduced levels of plasticizers thereby improving physical properties, compression set, heat aging, fluid extraction and adhesion to various substrates. Higher filler levels can also be used to decrease swell in fluids/fuels, improve permeation resistance, and decrease the cost.