IIR

Butyl Rubber (IIR)

Butyl rubber is composed by copolymerizing isobutylene which is with small amount of isoprene. It is like EPDM possessing excellent resistance to chemical and polar fluid, outstanding electrical insulation and good ozone resistance. The special properties of butyl rubber are low gas and moisture permeability and high shock absorption. These properties have made butyl rubber the polymer choice in a variety of applications.


Cure system - Sulfur-Cured

Standard IIRs are sulfur-cured.


Other Common Variations

IIRs can be formulated with only “white list” ingredients as specified in 21.CFR 177.2600 for use in applications where the elastomer will be in contact with food or beverages, ex. bottle top seal for alcohol or medical.


General Information

ASTM D 1418 Designation: IIR, CIIR, BIIR
ISO/DIN 1629 Designation: IIR, CIIR, BIIR
ASTM D2000 / SAE J 200 Codes: AA, BA
Standard Color(s): Black
Hardness Range: 50 to 80 Shore A
Relative Cost: Low


Service Temperatures

Standard Low Temperature: -55°C / -67°F
Standard High Temperature: 100°C / 212°F

Performs Well In...

Doesn't Perform Well In...

  • Alcohols
  • Ketones
  • Dilute acids and alkalis
  • Silicone oils & greases
  • Water and Steam
  • Phosphate ester based hydraulic fluids - Skydrol® 
  • Ozone, aging & weathering
  • Aliphatic & aromatic hydrocarbons
  • Halogenated solvents
  • Petroleum based oils & greases