Intumescent Additive
CAS Number: 68333-79-9
An intumescent additive based on ammonium polyphosphate (APP) chemistry that causes coatings to expand and form an insulating char layer when exposed to heat or flame. This expanding char significantly slows heat transfer to the underlying substrate, providing critical passive fire protection for structural steel and timber. Suitable for thin-film intumescent coatings targeting 30 to 120 minutes fire resistance ratings.
Technical Specifications
| pH | 5.5–7.0 |
| purity | ≥93% |
| appearance | White to off-white free-flowing powder |
Applications
- Structural steel fire protection coatings
- Load-bearing timber fire retardant finishes
- Cable tray and electrical conduit fire barriers
- Fireproof coatings for oil and gas processing equipment
- Building joint and penetration fire sealing systems
Key Features
- Rapid char expansion ratio exceeding 50:1 on ignition
- Excellent compatibility with waterborne and solvent-borne intumescent systems
- Provides 30 to 120-minute structural fire resistance ratings
- Low smoke and low toxicity combustion by-products