CIIR - Chlorobutyl rubber

Clwyd reference CIIR
ASTM classification CIIR
Typical applications
  • ‘O’ Rings
  • Vacuum seals and membranes
  • Steam hoses
  • Pharmaceutical closures
  • Tire inner tubes
  • High impermeability
  • Better heat resistance
  • Addition of bromine results in faster curing and better adhesion to unsaturated polymers
Lower resilience
Available hardness range (Shore A) 35 - 90
Upper continuous service temp. 130°C
Min. temp. for sealing applications -50°C
Minimum non-brittle  temp.  -70°C
Tensile strength (up to) 18 MPa
Elongation at break (up to) 650%
Price Bracket Very low
ASTM 1 Oil None
ASTM 2 Oil None
ASTM 3 Oil None
Kerosene None
Liquid B None
Liquid 101 None
Phosphate ester Good
Ketone Good
Toluene None
Iso-octane None
Methanol Excellent
Acid (weak) Good
Acid (strong) None
Base (weak) Excellent
Base (strong) Good
Hydrogen sulphide Excellent
Steam Good
Ozone Excellent
Radiation Good