APP (Ammonium Polyphosphate)

Product Name: APP (Ammonium Polyphosphate)
CAS No.: 68915-31-1
Category: Halogen-Free Intumescent Flame Retardant / Acid-Source Component
Note: Type-I (low polymerization degree, relatively high water solubility); Type-Ⅱ (high polymerization degree, low water solubility, mainstream flame-retardant grade)
Brief Introduction
Ammonium Polyphosphate (APP) is the most widely used halogen-free phosphorus-nitrogen intumescent flame retardant and classic acid source for intumescent systems. Upon heating, it releases phosphoric acid species to catalyze carbon-source dehydration and char formation. Together with carbon sources (e.g. pentaerythritol) and gas sources (e.g. melamine), it builds a dense intumescent char layer that blocks heat and oxygen. TypeⅡ APP features high polymerization degree, extremely low water solubility and improved weather resistance. 

Key Advantages
- High phosphorus & nitrogen content, high flame-retardant efficiency
- Type Ⅱ grade: low water solubility, low migration, good outdoor stability
- Halogen-free, low smoke, heavy-metal-free, meets RoHS / REACH
- Excellent synergism with pentaerythritol, melamine, MPP, PAP
- Good dispersion in coatings, resins and polymer systems
- Cost‑effective standard acid source for intumescent formulations
Applications
- Steel-structure intumescent fire-retardant coatings
- Water-based & solvent-based fireproof paints
- Intumescent flame-retardant masterbatch & polyolefin compounds
- Epoxy, polyurethane, powder coatings
- General-purpose P-N synergistic flame retardant systems
Packing
25kg kraft paper bag / PE lined bag, palletized packaging