Common Names: Butyl
Chemical Name: Isobutylene Isoprene
ASTM D1418 Designation: IIR
ISO/DIN 1629 Designation: IIR
ASTM D2000/SAE J200 Type, Class: AA,BA
Description: An all-petroleum product, Butyl is a copolymer of isobutylene and isoprene and has largely been replaced by Ethylene Propylene since its introduction.
Key Use(s): Highly effective in vacuum sealing applications. Good seal for hydraulic systems.
Standard Compound: -50°C (-50°F) to +121°C (250°F)
Hardness (Shore A): 40 to 90
Features: With outstanding low permeability to gases, Butyl is especially effective in vacuum sealing applications. It also features good to excellent resistance to ozone and sunlight aging.
Limitations: Because it is a petroleum product, Butyl has poor resistance to hydrocarbon solvents and oils, and diester-based lubricants.