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Send EmailButyl Rubber, Isobutylene Isoprene Rubber, IIR, 9010-85-9
BUTYL RUBBER (IIR)
Butyl Rubber / Isobutylene Isoprene Rubber / IIR / Poly(isobutylene-co-isoprene)
CAS Number: 9010-85-9
EINECS: 618-368-0
1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY
| Parameter | Description |
|---|---|
| Product Name | Butyl Rubber (IIR) |
| Other Names | Isobutylene-Isoprene Rubber, IIR, Poly(isobutylene-co-isoprene) |
| CAS Number | 9010-85-9 |
| EINECS | 618-368-0 |
| Chemical Formula | −[CH₂–C(CH₃)₂]ₘ−[CH₂–C(CH₃)=CH–CH₂]ₙ− |
| Monomers | Isobutylene (~98%) and Isoprene (~2%) |
| Chemical Class | Synthetic elastomer (copolymer) |
| Appearance | White to light yellow solid (bales) |
| Odor | Characteristic rubber odor |
| Density | 0.91 - 0.93 g/cm³ |
| Glass Transition Temperature (Tg) | ~ -65°C |
| Service Temperature Range | -50°C to +120°C |
Butyl Rubber (IIR) is a copolymer produced by the cationic polymerization of isobutylene (~98%) and a small amount of isoprene (~2%) monomers. The isoprene provides a limited number of double bonds (unsaturation) in the polymer chain, enabling crosslinking (vulcanization) with sulfur or other vulcanizing agents. Butyl Rubber has the lowest gas permeability among all elastomers (approximately 1/10th of natural rubber). It is also known for excellent ozone, weather, and chemical resistance, high damping (vibration absorption) properties, and a wide service temperature range. It is widely used in automotive (inner tubes, tire inner liners), pharmaceutical (vial stoppers, syringe plungers), construction (roofing membranes, sealing profiles), and adhesive industries. It should not be confused with Polyisobutylene (PIB), which is a fully saturated polymer without isoprene and cannot be vulcanized.
2. HALOGENATED BUTYL RUBBER TYPES
| Type | Description | Advantages | Applications |
|---|---|---|---|
| Bromobutyl (BIIR) | Bromine-halogenated butyl rubber | Faster vulcanization, better adhesion to other elastomers | Tire inner liners, inner tubes, industrial products |
| Chlorobutyl (CIIR) | Chlorine-halogenated butyl rubber | Good adhesion, good heat resistance | Tire liners, pharmaceutical stoppers, adhesives |
| Halogenated Butyl | General term | Improved processability and adhesion | Specialty applications, blends |
3. TECHNICAL SPECIFICATIONS
Typical Properties of Butyl Rubber:
| Parameter | Value |
|---|---|
| Isobutylene Content | ~98% |
| Isoprene Content | ~2% |
| Unsaturation (Double Bonds) | Low (~2%) |
| Mooney Viscosity (ML 1+4, 100°C) | 40-80 MU (grade dependent) |
| Density | 0.91 - 0.93 g/cm³ |
| Glass Transition Temperature (Tg) | ~ -65°C |
| Service Temperature Range | -50°C to +120°C |
| Tensile Strength (vulcanized) | 15-20 MPa |
| Elongation at Break (vulcanized) | 400-600% |
| Gas Permeability (Air) | ~1/10th of natural rubber |
| Ozone Resistance | Excellent |
| Weather Resistance | Excellent |
| Aging Resistance | Excellent |
| Water Vapor Permeability | Very low |
| Damping | Excellent |
| Oil Resistance | Poor |
| Abrasion Resistance | Low |
| Electrical Insulation | Good |
4. PHYSICAL AND CHEMICAL PROPERTIES
| Property | Value |
|---|---|
| Density | 0.91 - 0.93 g/cm³ |
| Glass Transition Temperature (Tg) | ~ -65°C |
| Service Temperature Range | -50°C to +120°C |
| Tensile Strength (vulcanized) | 15-20 MPa |
| Elongation at Break (vulcanized) | 400-600% |
| Gas Permeability | ~1/10th of natural rubber |
| Ozone Resistance | Excellent |
| Weather Resistance | Excellent |
| Aging Resistance | Excellent |
| Oil Resistance | Poor |
| Abrasion Resistance | Low |
| Water Resistance | Excellent |
| Acid Resistance | Good |
| Alkali Resistance | Good |
| Electrical Insulation | Good |
| Damping | Excellent |
| Solubility | Soluble in aliphatic and aromatic hydrocarbons; insoluble in oils and polar solvents (swells) |
5. ADVANTAGES OF BUTYL RUBBER
| Advantage | Description |
|---|---|
| Lowest Gas Permeability | Lowest air, nitrogen, and oxygen permeability among all elastomers |
| Excellent Ozone Resistance | Much more resistant to ozone and weathering than natural rubber |
| High Chemical Resistance | Resistant to acids, bases, and many chemicals |
| Excellent Damping | High energy absorption and vibration damping properties |
| Wide Temperature Range | Usable from -50°C to +120°C |
| Low Toxicity | Suitable for medical applications |
| Low Water Vapor Permeability | Excellent barrier against water vapor |
| Good Electrical Insulation | Suitable for electrical insulation applications |
6. LIMITATIONS
| Limitation | Description |
|---|---|
| Poor Oil and Fuel Resistance | Swells and degrades when in contact with oils and fuels |
| Low Abrasion Resistance | Lower than natural rubber and SBR |
| Slow Vulcanization | Halogenated derivatives (BIIR, CIIR) vulcanize faster |
| High Cost | More expensive than natural rubber and SBR |
| Adhesion Issues with Other Elastomers | Improved by halogenation |
| Thermal Degradation | Degrades above 200°C, releasing toxic gases |
7. APPLICATIONS AND INDUSTRIAL USES
7.1. Automotive Industry (Largest Application)
| Application | Description |
|---|---|
| Inner Tubes | Bicycle, motorcycle, and automobile inner tubes |
| Tire Inner Liners (Tubeless) | Air-tight layer inside the tire |
| Tire Inner Liners | Halogenated butyl used for tire inner liners |
| Vibration Dampers | Engine mounts and suspension components |
| O-Rings | Chemical resistance applications |
| Hoses | Chemical transfer hoses |
7.2. Pharmaceutical and Medical Industry
| Application | Description |
|---|---|
| Vial Stoppers | Rubber stoppers for injectable drug vials |
| Syringe Plungers | Syringe piston seals |
| Dropper Bulbs | Eye and nasal droppers |
| Medical Tubes | Medical tubing and hoses |
| Sterile Packaging | Sterilization-resistant closures |
7.3. Construction and Building Materials
| Application | Description |
|---|---|
| Roofing Membranes | Flat roof coverings (not to be confused with EPDM) |
| Waterproofing Tapes | Joint and waterproofing tapes |
| Window Sealing Profiles | Window and door seals |
| Expansion Joints | Building expansion joint seals |
7.4. Adhesives and Sealants
| Application | Description |
|---|---|
| Pressure-Sensitive Adhesives (PSA) | Tape and envelope adhesives |
| Sealing Tapes | HVAC systems, automotive sealing |
| Self-Adhesive Tapes | Industrial and consumer tapes |
7.5. Industrial Applications
| Application | Description |
|---|---|
| Vacuum Seals | High-vacuum applications |
| Vibration Dampers | Industrial machinery |
| Chemical Hoses | Acid and base transfer hoses |
| Shoe Soles | Chemical protective boots |
7.6. Specialty Applications
| Application | Description |
|---|---|
| Chewing Gum Base | Low molecular weight PIB |
| Explosive Carriers | Inertness and flexibility |
| Radiation Shielding | Neutron absorption (high hydrogen content) |
8. COMPARISON WITH OTHER RUBBER TYPES
| Property | Butyl Rubber (IIR) | Natural Rubber (NR) | SBR | EPDM |
|---|---|---|---|---|
| Gas Permeability | Lowest | High | High | Moderate |
| Ozone Resistance | Excellent | Poor | Poor | Excellent |
| Oil Resistance | Poor | Poor | Poor | Poor |
| Abrasion Resistance | Low | Excellent | Excellent | Good |
| Damping | Excellent | Good | Moderate | Good |
| Temperature Range | -50°C to +120°C | -50°C to +80°C | -40°C to +90°C | -40°C to +130°C |
| Cost | High | Moderate | Low | Moderate |
9. HALOGENATED BUTYL RUBBER ADVANTAGES
| Property | BIIR (Bromobutyl) | CIIR (Chlorobutyl) |
|---|---|---|
| Vulcanization Speed | Fast | Moderate |
| Adhesion | Excellent | Good |
| Heat Resistance | Good | Good |
| Gas Permeability | Very low | Very low |
| Applications | Tire inner liners, tubes | Pharmaceutical stoppers, adhesives |
10. PACKAGING AND SHIPPING
| Packaging Option | Details |
|---|---|
| Bale Weight | 33.33 kg or 35 kg |
| Bale Dimensions | ~70 cm x 35 cm x 18 cm |
| Pallet Configuration | 36 bales/pallet = 1.26 MT |
| Pallet Type | Wooden pallet, shrink-wrapped |
| Container Capacity (20-ft) | 16 pallets = 20.16 MT |
| Container Type | Standard 20-ft container |
11. STORAGE AND HANDLING
| Parameter | Information |
|---|---|
| Storage Conditions | Cool, dry, well-ventilated area; away from direct sunlight |
| Recommended Temperature | Below 25°C |
| Humidity | Avoid high humidity to prevent mold growth |
| Shelf Life | 12-24 months under proper storage conditions |
| Handling | Avoid contamination with oils, solvents, and dirt |
| Protection | Keep bales covered and protected from moisture and dust |
| Stacking | Maximum 4-5 pallets high for stable storage |
12. SAFETY AND HEALTH INFORMATION
| Parameter | Information |
|---|---|
| Toxicity | Non-toxic |
| Skin Irritation | Non-irritant |
| Eye Irritation | Mild irritant (dust) |
| Inhalation | May cause respiratory irritation (dust) |
| Flammability | Combustible (produces dense black smoke when burning) |
| Fire Extinguishing Media | Water spray, foam, CO₂, dry chemical powder |
| Special Hazards | Degrades above 200°C, releasing toxic gases (CO, hydrocarbons) |
13. FIRST AID MEASURES
| Exposure Route | Action |
|---|---|
| Inhalation | Move person to fresh air. If irritation persists, seek medical attention. |
| Skin Contact | Wash with soap and water. Remove contaminated clothing. |
| Eye Contact | Rinse with plenty of water for at least 15 minutes. Seek medical attention if irritation persists. |
| Ingestion | Rinse mouth. Do NOT induce vomiting. Seek medical attention if large amounts are swallowed. |
14. REGULATORY INFORMATION
| Region | Status |
|---|---|
| EU | REACH registered |
| Turkey (KKDİK) | Mandatory compliance; requires registration |
| USA (TSCA) | Listed |
| Canada (DSL) | Listed |
| Australia (AICS) | Listed |
| Japan (ENCS) | Listed |
| Korea (KECL) | Listed |
| China (IECSC) | Listed |
Regulatory Status:
| Status | Information |
|---|---|
| HS Code | 40023100 |
| CAS Number | 9010-85-9 |
| EINECS | 618-368-0 |
| IARC Classification | Not classified |
| WGK Germany | 1 (slight hazard to water) |
15. OTHER NAMES AND DATABASE IDENTIFIERS
| Category | Names / Identifiers |
|---|---|
| Product Names | Butyl Rubber, Butyl, IIR, Isobutylene-Isoprene Rubber |
| Halogenated Derivatives | BIIR (Bromobutyl), CIIR (Chlorobutyl) |
| Trade Names | Exxon Butyl, Lanxess Butyl, Nipol Butyl |
| Common Names | Butyl, Butyl Rubber, IIR |
Database Identifiers:
| Database | Identifier |
|---|---|
| CAS | 9010-85-9 |
| EINECS | 618-368-0 |
| HS Code | 40023100 |
16. BUTYL RUBBER VS. POLYISOBUTYLENE (PIB)
| Property | Butyl Rubber (IIR) | Polyisobutylene (PIB) |
|---|---|---|
| Isoprene Content | ~2% | None (fully saturated) |
| Vulcanization | Vulcanizable with sulfur | Not vulcanizable |
| Molecular Structure | Copolymer | Homopolymer |
| Applications | Tires, stoppers, seals | Adhesives, grease thickeners, films |
17. INDUSTRY SUITABILITY TABLE
| Industry | Applications | Recommended Type | Suitability |
|---|---|---|---|
| Automotive | Inner tubes, tire inner liners, vibration dampers | IIR, BIIR, CIIR | High |
| Pharmaceutical/Medical | Vial stoppers, syringe plungers | IIR, CIIR | High |
| Construction | Roofing membranes, waterproofing tapes, window seals | IIR, BIIR | High |
| Adhesives | PSA tapes, sealing tapes | IIR, PIB | High |
| Industrial | Vacuum seals, chemical hoses | IIR, BIIR | High |
18. STRENGTHS AND WEAKNESSES OF BUTYL RUBBER
| Strengths | Weaknesses |
|---|---|
| Lowest gas permeability | Poor oil and fuel resistance |
| Excellent ozone and weather resistance | Low abrasion resistance |
| High chemical resistance | Slow vulcanization |
| Excellent damping (vibration absorption) | High cost |
| Wide temperature range (-50°C to +120°C) | Adhesion issues with other elastomers |
| Low toxicity | Thermal degradation (above 200°C) |
| Low water vapor permeability |
19. ROLE OF BUTYL RUBBER IN TIRE APPLICATIONS
| Component | Function | Type Used |
|---|---|---|
| Inner Tube | Air sealing, pressure retention | IIR |
| Tubeless Tire Inner Liner | Air barrier | BIIR, CIIR |
| Tire Inner Liner | Air retention | BIIR |
| Vibration Damper | Comfort and ride quality | IIR |
20. SUMMARY AND CRITICAL WARNINGS
SUMMARY:
Butyl Rubber (IIR) is a synthetic elastomer produced by the cationic polymerization of isobutylene (~98%) and isoprene (~2%) monomers. It has the lowest gas permeability among all elastomers (approximately 1/10th of natural rubber). It is known for excellent ozone, weather, and chemical resistance, high damping, and a wide temperature range (-50°C to +120°C). Halogenated derivatives (BIIR, CIIR) offer faster vulcanization and better adhesion. It is used in automotive (inner tubes, tire inner liners), pharmaceutical (vial stoppers, syringe plungers), construction (roofing membranes, sealing profiles), and adhesives. Oil resistance is poor, and abrasion resistance is low. It should not be confused with Polyisobutylene (PIB). HS Code: 40023100.
Key Properties:
| Property | Value |
|---|---|
| Appearance | White to light yellow solid (bales) |
| CAS Number | 9010-85-9 |
| Density | 0.91 - 0.93 g/cm³ |
| Glass Transition Temperature | ~ -65°C |
| Gas Permeability | ~1/10th of natural rubber |
| Primary Types | IIR, BIIR, CIIR |
| Primary Use | Tire inner tubes, inner liners, pharmaceutical stoppers |
Major Application Areas:
| Industry | Applications |
|---|---|
| Automotive | Inner tubes, inner liners, vibration dampers |
| Pharmaceutical/Medical | Vial stoppers, syringe plungers |
| Construction | Roofing membranes, waterproofing tapes |
| Adhesives | PSA tapes, sealing tapes |
| Industrial | Vacuum seals, chemical hoses |
Key Safety Points:
-
NON-TOXIC: Generally safe for handling
-
COMBUSTIBLE: Can burn; keep away from ignition sources
-
STORAGE: Store in cool, dry, well-ventilated area; avoid direct sunlight and high humidity
-
PPE RECOMMENDED: Dust mask, safety goggles, protective gloves (for handling)
-
PROTECT: Keep away from oils, solvents, and contaminants
CRITICAL WARNINGS:
-
Butyl Rubber has the lowest gas permeability among all elastomers (approximately 1/10th of natural rubber). This property makes it indispensable for inner tubes and tubeless tire inner liners.
-
Halogenated derivatives (BIIR, CIIR) offer faster vulcanization and better adhesion to other elastomers.
-
Butyl Rubber swells and degrades when in contact with oils and fuels. Oil resistance is poor.
-
Abrasion resistance is lower than natural rubber and SBR. Therefore, it is used in inner tubes rather than tire treads.
-
Butyl Rubber should not be confused with Polyisobutylene (PIB). PIB is a fully saturated polymer without isoprene and cannot be vulcanized.
-
Butyl Rubber degrades above 200°C, releasing toxic gases (carbon monoxide, hydrocarbons).
-
Ozone, UV, and aging resistance is much better than natural rubber.
-
High damping properties make it ideal for vibration and noise insulation applications.
-
Low toxicity and sterilization resistance (autoclave) provide advantages in medical applications.
Important Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. The information provided is based on available data and is believed to be accurate. However, the user is solely responsible for determining the suitability of the product for their specific application and for complying with all applicable regulations and safety requirements. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier.
