Intumescent system based on APP for light weight composite and gel-coat applications where lower viscosity is required
Exolit™ AP 742
Fecha de edición :
febrero 06, 2026
Exolit AP 742 is a non-halogenated, additive flame retardant based on ammonium polyphosphate, which develops its effectiveness through a phosphorus/nitrogen synergism. Exolit AP 742 differs in its mode of action from other flame retardant technologies (e.g. chlorine- or bromine-containing flame retardants and minerals) by achieving its effect through intumescence and shows a reduced viscosity in unsaturated polyester resins. The flame retarded material foams on exposure to flame. The carbon foam layer so formed protects the polymer by its heat-insulating effect and reduces further oxygen access.
Product Information
Beneficios
- Non-halogenated, additive flame retardant based on ammonium polyphosphate, which develops its effectiveness through a phosphorus/nitrogen synergism
- Differs in its mode of action from other flame retardant technologies (e.g. chlorine- or bromine-containing flame retardants and minerals) by achieving its effect through intumescence
- May be used in a range of thermoset resins, especially unsaturated polyester resin where it shows a reduced viscosity compared to the AP 740 series
- Suitable for coatings, laminates and reinforced materials
- Can be used on its own to formulate intumescent polyester gel coats which meet construction and transportation standards
- In composites, it can be used either alone or in combination with filler flame retardants like aluminum trihydrate (ATH), which allows the substitution of a significant part of the ATH by using the higher performance Exolit AP 742 whilst maintaining the flammability rating. This effect is especially important where weight is a factor in the finished formulation or article (e.g. mass transportation or aerospace applications)
- Non-halogenated flame retardant with favorable environmental and health profile
For regulatory details such as the classification and labelling as dangerous substances or goods please refer to our corresponding Material Safety Data Sheet.
| Characteristics | Unit | Target value | DS¹) | TD²) | Test method |
| Appearance | white powder |
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visual evaluation | ||
| Phosphorus | % (w/w) | 21.0 - 23.0 |
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Photometry after oxidizing dissolution; (11/17) | |
|
Nitrogen |
% (w/w) |
19.0 - 22.0 |
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Elemental analysis; (11/07) | |
| Density | g/cm³ | approx. 1.8 |
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| Bulk Density | g/cm³ | approx. 0.6 |
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| Solubility in Water | % (w/w) | < 2.0 |
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(at 25 °C in 10 % suspension) | |
| Decomposition Temperature | °C | > 200 |
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||
| Average Particle Size (D50) | µm | approx. 16 |
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| Particle Size Distribution | % (w/w) |
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| > 100 µm | < 2 | ||||
| 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. |
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Exolit AP 742 may be used in a range of thermoset resins, especially unsaturated polyester resin and acrylic resins. It is suitable for coatings, laminates and reinforced materials. In addition to primary effects of fire such as spread of flames and residual length, secondary effects such as the reduction in smoke density and formation of toxic smoke is of interest.
Exolit AP 742 on its own can be used to formulate intumescent polyester gel coats which meet construction standards.
In composites Exolit AP 742 can be used either alone or in combination with filler flame retardants like aluminum trihydrate (ATH).
Formulations and achievable flame retardant effect
Exolit AP 742 can be used to achieve high flame retardant requirements in unsaturated polyester resins. Typical dosing rates for Exolit AP 742 are 25 – 75 phr UP resin, but depend heavily on resin used and flammability rating required. Exolit AP 742 can also be used together with other flame retardants. A good example is the combination of Exolit AP 742 with aluminum trihydrate (ATH), which allows the substitution of a significant part of the ATH by using the higher performance Exolit AP 742 whilst maintaining the flammability rating. This effect is especially important where weight is a factor in the finished formulation or article (e.g. mass transportation or aerospace applications).
Exolit AP 742 on its own can be used to formulate intumescent polyester gel coats which meet construction standards.
In composites Exolit AP 742 can be used either alone or in combination with filler flame retardants like aluminum trihydrate (ATH).
Formulations and achievable flame retardant effect
Exolit AP 742 can be used to achieve high flame retardant requirements in unsaturated polyester resins. Typical dosing rates for Exolit AP 742 are 25 – 75 phr UP resin, but depend heavily on resin used and flammability rating required. Exolit AP 742 can also be used together with other flame retardants. A good example is the combination of Exolit AP 742 with aluminum trihydrate (ATH), which allows the substitution of a significant part of the ATH by using the higher performance Exolit AP 742 whilst maintaining the flammability rating. This effect is especially important where weight is a factor in the finished formulation or article (e.g. mass transportation or aerospace applications).
Delivery form
White, free-flowing powder
Packaging
Exolit AP 742 is supplied in 25 kg net bags. The standard supply unit is a shrink-wrapped pallet with 40 bags weighing 1000 kg net.
Storage
Minimum shelf life is 12 months from the date of shipping when stored according to the said conditions.
White, free-flowing powder
Packaging
Exolit AP 742 is supplied in 25 kg net bags. The standard supply unit is a shrink-wrapped pallet with 40 bags weighing 1000 kg net.
Storage
Minimum shelf life is 12 months from the date of shipping when stored according to the said conditions.
