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CR
Material Type
Rubber
Material Full Name
Chloroprene Rubber
Process Compatibility
Injection Molding, Compression Molding
Basic Properties
Property |
Parameter/Performance |
Remarks |
|---|---|---|
| Chemical Name | Chloroprene Rubber | Polymerized from 2-chloro-1,3-butadiene (polar chlorine atoms) |
| Molecular Structure | Crystalline elastomer | Self-reinforcing in raw state (high green strength) |
| Density | 1.23~1.30 g/cm³ | 30% heavier than NR/SBR |
| Color | Milky white to light yellow (colorable) | Opaque, darkens with aging |
| Mechanical Properties | ||
| – Tensile Strength | 20-35 MPa (cured) | Green strength: 10-15 MPa (superior to most rubbers) |
| – Elongation at Break | 300-800% | Moderate elasticity (rebound: 50-65%) |
| – Wear Resistance | Better than NR (abrasion loss 0.4-1.0 cm³/1.61 km) | Ideal for dynamic seals |
| Thermal Properties | ||
| – Service Temperature | -40℃~120℃ (short-term 150℃) | Inferior low-temp performance vs NR (Tg: -40℃) |
| – Flammability | LOI 26-32% (self-extinguishing) | UL94 HB without additives |
| Chemical Properties | ||
| – Ozone Resistance | Excellent (>500h @ 100pphm ozone) | Outdoor service life >10 years |
| – Chemical Resistance | Resists oils/solvents/acids/alkalis (better than NR/SBR) | Fuel resistance between NBR and NR |
Processing Characteristics
Mastication Required:
- Open mill mixing (40-50℃) to reduce Mooney viscosity
Curing Systems:
- Metal oxide vulcanization (4-5 phr ZnO + 5 phr MgO)
- Avoid sulfur (scorches easily)
Molding Processes:
- Compression (150-170℃×10-20 mins)
- Extrusion (die temp: 70-90℃)
Common Application Areas
-
Automotive: Engine mounts, AC hoses
-
Industrial: Conveyor belt covers, oil-resistant seals
-
Construction: Bridge bearings, seismic pads
-
Electrical: Cable jackets, insulation layers
EPDM Modified Types
Type |
Characteristics |
Typical Applications |
|---|---|---|
| General-Purpose CR | Balanced mechanical/weathering properties | Seals, hoses |
| Adhesive CR | Contains methacrylic acid (bonds to metal/fabric) | Rubber-metal composites, conveyor belts |
| Flame-Retardant CR | LOI >30% (with antimony trioxide) | Mining cable sheaths, fire seals |
| Low-Crystallinity CR | Better low-temp flexibility (soft at -50℃) | Cold-resistant hoses, freezer gaskets |
| Pre-crosslinked CR | Partially vulcanized (improves dimensional stability) | Complex molded parts |
Advantages & Disadvantages
Advantages |
Disadvantages |
|---|---|
| Outstanding weather/ozone resistance (>10 years outdoor) | High density (heavy parts) |
| Inherent flame retardancy (self-extinguishing) | Poor low-temp elasticity |
| Better oil/solvent resistance vs NR/SBR | Releases HCl during curing (ventilation needed) |
Other Elastomer & Rubber Material Selection
NR Rubber
PU Rubber
IIR Rubber
FKM Rubber
TPU Rubber
FAQ Of CR Materials
Visit our FAQ center for more questions.
What are the fundamental properties of CR rubber?
CR rubber (Chloroprene/Neoprene), polymerized from chloroprene, exhibits outstanding weather resistance, flame retardancy (self-extinguishing) and moderate oil resistance, while maintaining good mechanical strength with an operating temperature range of -40℃ to 120℃.
How does CR differ from NBR in performance?
Compared to NBR, CR offers superior weather resistance, UV stability and flame retardancy, though with slightly inferior oil resistance. CR also surpasses most general-purpose rubbers in mechanical strength and dynamic fatigue resistance.
What are typical industrial applications of CR rubber?
- Automotive timing belts/weatherstrips
- Cable sheathing
- Corrosion-resistant linings
- Seismic isolation bearings
- Specialty products like wetsuits/protective clothing