IIR (isobutylene-isoprene rubber or butyl rubber, bucar, PIB)

This is a synthetic rubber, obtained by copolymerization of isobutylene with 1-3 % of isoprene. It is gas-tight, so it is usually used in airtight products. Its most noticeable characteristics are extremely high ozone resistance and good wear resistance.


car and bicycle inner tubes, gaskets, membranes, anti-vibration components.


  • resistant to weather, oxygen, ozone, UV, water, alcohols, heat, alkaline solution, acid, animal and vegetable oils,
  • wear resistance,
  • good electrical properties.


  • poor resistance to fuels, mineral oil and kerosene.

Temperature resistance: from – 60 °C to 130 °C.

Hardness: 30 to 80 Shore A.