322 – Chlorobutyl (CIIR)

ASTM D2000 Classification: BA


Temperature Range:

Low Temp:    -55°C (-70°F)          Brittle -60°C (-80°F)

High Temp:   105°C (220°F)        Intermittent 120°C (250°F)



Chlorobutyl rubber is an isobutylene-isoprene copolymer derived from reacting butyl rubber with chlorine in a continuous process. Compared with regular butyl rubber, Chlorobutyl rubber provides an improved compression set and better resistance to heat, ozone and flex fatigue.

Low permeability to air, gases and moisture.

Vibration damping.

Low glass transition temperature, similar to regular butyl.

Wide vulcanization versatility.

Fast cure rates.

Processing safety: no nitrosamines or nitrosamines precursors.

Good adhesion and compatibility to other rubbers.


EMI ReferenceSpecificationShoreSGTensile Strength (MPa)Elongation at Break %Colour
322 – CIIR301 Good Commercial30°0.9314400
322 – CIIR401 Good Commercial40°1.387400
322 – CIIR402 Good Commercial40°0.9315400
322 – CIIR451 Good Commercial45°0.9315400
322 – CIIR501 Good Commercial50°0.935370
322 – CIIR501 Good Commercial50°1.37280
322 – CIIR601 Good Commercial60°1.48450
322 – CIIR601 Good Commercial60°1.447450

Full data sheets for all grades are available on request.

* The information above is supplied in good faith and believed to be correct. This information is supplied upon the condition that persons receiving this will make their own determination as to its suitability for their purposes prior to use. EMI makes no representations or warranties, either expressed or implied with respect to the information or the product to which this information refers.