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Exolit® AP 423

Micronized APP (phase II) with extremely low water solubility

Edition Date :
August 19, 2021

Exolit AP 423 is a very fine-particle ammonium polyphosphate produced by a special method. The crystal modification is phase II. The product is largely insoluble in water and completely insoluble in organic solvents. It is a white powder, halogen free and non-flammable. 

Benefits

  • Low solubility in water, low viscosity in aqueous suspensions and a low acid number
  • Imparts a good flame-retardant effect to adhesives and sealants when incorporated into the base formulation at the rate of 10 - 20%
  • Particularly suitable as an ”acid donor” for intumescent coatings thanks to its low water solubility. Steel structures coated with intumescent paints can meet the requirements of fire resistance classes specified in EN, DIN, BS, ASTM and others
  • The application of Exolit® AP 423 based intumescent coatings on wood or plastics enables these materials to qualify for Building Material Class B (DIN EN 13501-1)
  • Can be used in transport applications to obtain good fire, smoke and toxicity results (EN 45545)
  • (Bio-)degradable by breaking down to naturally occurring phosphate and ammonia
  • Non-halogenated flame retardant with favorable environmental and health profile

 

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Safety

For regulatory details such as the classification and labelling as dangerous substances or goods please refer to our corresponding Material Safety Data Sheet.

Specifications

Characteristics  Unit   Target value   DS¹)    TD²)  Test method 
Chemical Formula  [NH4PO3]n
n > 1000  

Phosphorus  %(w/w)   31.0 - 32.0  

Photometry after oxidizing dissolution; (11/17)  
Water / Moisture  %(w/w)   max. 0.5  

Thermogravimetry at 130 °C; (11/03)  
Nitrogen  %(w/w)   14.0 - 15.0  

Elemental analysis; (11/07)  
Density  g/cm³   1.9  

at 25 °C  
Bulk Density  g/cm³   approx. 0.7  

Viscosity  mPa*s   max. 100  

at 25 °C in 10 % aqueous suspension  
pH Value  5.0 - 7.5  

Potentiometry in 10 % aqueous suspension; (11/12)  
Solubility in Water  %(w/w)   max. 1.0  

Gravimetry after filtration of a 10 % aqueous suspension at 25°C; (11/41)  
Decomposition Temperature  °C   > 275  

initial evolution of ammonia  
Average Particle Size (D50)  µm   approx. 8  

 
Particle Size Distribution  %(w/w)  

Air jet sieving; (11/02)  
< 24 µm   min. 97 (TD)    
> 50 µm   max. 0.1 (DS)    
-  
-    
-    
¹) Delivery specification: The product is monitored on a regular basis to ensure that it adheres to the specified values. Test methods: Clariant method numbers 11/xx in brackets.
²) Technical data: The technical data are used solely to describe the product and are not subject to regular monitoring.  

Applications

Intumescent coatings
On account of its low water solubility, Exolit AP 423 is particularly suitable as an ”acid donor” for intumescent coatings. Other essential compo­nents of intumescent systems include a binder, a carbon donor (e.g. pentaerythritol) and a blowing agent (e.g. mela­mine).    

On exposure to flame, intumescent coatings form a carbonaceous foam which effectively shields the underlying material from temperature increases.

Steel structures coated with intumescent paints can meet the requirements of fire resistance classes specified in DIN, BS or ASTM.    

The application of Exolit AP 423 based intumescent coatings on wood or plastics enables these materials to qualify for Building Material Class B (DIN EN 13501-1).

Exolit AP 423 imparts a good flame-retardant effect to adhesives and sealants when it is incorporated into the base formulation at the rate of 10 - 20 %.

 

Other applications
In composites for transport applications it can be used to control fire, smoke and toxicity. Especially in railway (EN 45545-2) and aviation (FAR 25.853) applications low smoke density and toxicity is a key requirement.

Due to the fine particles it can be used for infusion processing technics.

Packaging and Handling

Delivery form
White powder

Packaging
Exolit AP 423 is packed in 25 kg bags. The standard supply unit is a shrink-wrapped pallet with 40 bags weig­hing 1000 kg net.

Storage
Minimum shelf life is 6 months from the date of shipping when stored according to the said conditions.

EcoTain®

Products that offer outstanding sustainability advantages are awarded Clariant’s EcoTain® label. EcoTain® products significantly exceed sustainability market standards, have best-in-class performance and contribute overall to sustainability efforts of the company and our customers. Find out more about: EcoTain®.
PeoplePEOPLE
People
    Non hazardous, studies on life cycle data available.
People
    Saves lives and assets as a (halogen free) flame retardant.
    PeoplePLANET
    People
      Phosphorus is on the EU list of critical raw materials but recycling is possible and actively investigated.
    People
      Supports the attainability of eco-labels for customer products.

     

      PeoplePERFORMANCE   
      People
        Joint developments with customers on formulations.
      People
        Constant high quality and hydrolytic stability.