IIR (Isobutylene-Isoprene Rubber)

Butyl rubber (IIR)

• IIR is also commonly referred to as butyl rubber, which is obtained by polymerizing isobutylene and a small amount of isoprene at approximately -100°C. It has excellent weather resistance, thus not requiring any special antioxidants, has good heat and aging resistance, ozone resistance, and chemical resistance, particularly being resistant to oxidants.
• It has excellent electrical properties, especially electrical insulation, corona resistance, and water resistance, and excellent properties, tear resistance, abrasion resistance, and bending and crack resistance. Although it has a weakness of low rebound resilience, it has high shock absorption, inversely, and thus it is effective a shock-resistant material, and as the elastomers are not crystallized, it remains flexible at very low temperatures (-50℃ or less).

Application

• Although it is used for tire tubes, leveraging its property of not passing through gas, other excellent properties are also utilized, gradually being applied to cable sheath, industrial goods, and rubber-coated fabric, therefore being known as a general type of rubber, rather than a special type of rubber. It is used to preserve gas (inner tubes of tires, vacuum seals, etc.) steam hoses, gaskets, printing rolls, medical stoppers, etc.

Property table of INEM materials (ASTM D2000)