Butyl Rubber (IRR) Sheet Type 91

sheet rubber roll

Butyl Rubber (IIR) is a copolymer of isobutylene with isoprene.   IIR stands for Isobutylene Isoprene Rubber.

Butyl Rubber is impermeable to air and is often used in applications requiring an airtight seal.  In fact, butyl performs 70% better than most other rubber compounds in air permeability.   It’s high strength makes it an excellent choice for shock absorption and it has great resistance to oils and high vapor chemicals.  Additionally it resists heat aging, UV Rays and chemical erosion and is abrasion resistant with above average tear resistance.

Applications include seals, flange gaskets, tire inner tubes and liners, sportball bladders, marine and electrical.

Available by the sheet, roll or cut piece.


  • Outstanding impermeability to gases and vapor.
  • Good resistance to heat, oxygen, ozone, sunlight, alkalis, oxygenated solvents, water, and steam.
  • High energy absorption (damping).
  • Good hot tear strength.


  • Duro: 60
  • Tensile: 750 psi
  • Elongation: 300%
  • Temperature: -30° to 230°F
  • Color: Black