Krynac® | Krynac® is the trade name of a series of oil-resistant acrylonitrile-butadiene rubbers (NBR) manufactured by emulsion polymerization. The product range consists of several grades of varying acrylonitrile content between 26% and 50% and varying Mooney viscosity of between 30 and 110. Some special grades, Krynac® X grades, are terpolymers of acrylonitrile, butadiene and an unsaturated carboxylic acid and are intended for applications that are subject to extreme stress and wear. In addition, a terpolymer of acrylonitrile, butadiene and styrene is available. A further range of special grades are ground or spray dried grades for thermoplastic modification and friction linings (Baymod® N). The acrylonitrile content primarily influences the swelling properties: with increasing acrylonitrile content the resistance to swelling, oils, greases and fuels is improved.
Krynac® NBR polymers are suitable for various applications in industrial equipment and machinery: Krynac® is used for hydraulic hoses, fuel and oil supply hoses, seals, rollers, drive belts, fabric linings and gaskets. Other applications are shoe soles (sport shoes and safety footwear) and flooring. In addition, Krynac® (or Baymod® N) is the base polymer for several automotive applications, such as hoses, oil seals and friction linings.
Most Krynac® grades meet the legal requirement for food grade articles intended for repeated use. Therefore food supply hoses, milking inflation tubes or conveyor belts for foodstuffs (fats and greases) are based on Krynac®.
Key Properties
- very good resistance to mineral oils, greases and fuels
- good resistance to aging
- high resistance to wear and abrasion (especially Krynac® X)
- low permeability to gases
- good dynamic fatigue resistance
- good low temperature properties
- reasonable cost level
- good ozone resistance (Krynac/PVC blends)
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