Clariant Launches Antimony Trioxide-Free Flame Retardant for the High-Voltage Electric Mobility Sector

For formulation R&D companies in the electric mobility sector focused on flame-retardant modified PBT materials, two newly launched Exolit OP series flame retardants from Clariant are currently available for evaluation. Both products will be exhibited at the 2025 K Fair in Germany. This product series is developed for high-voltage electrical and electronic systems, where electrical insulation performance and long-term stability are the key material selection criteria.

Clariant has completed a CHF 100 million expansion investment at its Daya Bay production base, and the second production line was put into operation in November last year. The new production capacity is primarily aimed at meeting the growing demand for flame retardant solutions in the Asia-Pacific region and the new energy electric vehicle sector.

No need to pair with PTFE, simplifying formulation development.

Clariant introduced Exolit OP 1242 (TP), which is designed for hydrolysis resistance, and Exolit OP 1266 (TP), which can maintain a comparative tracking index (CTI) of 600 V even after long-term storage. The manufacturer stated that, at an addition level of 15%–20%, both products can achieve a UL 94 V-0 rating on thin specimens of 0.4 mm.

The above performance is compatible with equipment on 800V and higher high-voltage platforms, for which insulation and durability under long-term operating conditions are key design challenges.

Both new products are halogen-free flame retardants that can replace traditional antimony trioxide (ATO)-based synergistic flame-retardant systems. In recent years, antimony raw material prices have fluctuated significantly and supply has been unstable. In addition, this product series does not require the use of fluoropolymer additives such as polytetrafluoroethylene (PTFE). Formulation engineers may evaluate and select the appropriate option based on their specific application conditions, OEM standards, and certification requirements.

In addition, Clariant has expanded its Exolit AP product line by launching Exolit AP 422 A, a halogen-free ammonium polyphosphate flame retardant suitable for insulation materials, composites, and intumescent fire-protection coatings.

Melamine is listed as a substance of very high concern (SVHC) under the EU REACH Regulation; Clariant states that Exolit AP 422 A contains less than 0.1% melamine, complies with Article 31 of the REACH Regulation, and is not subject to SVHC control.

In the field of polyurethane foam, this product can replace TCPP (tris(1-chloro-2-propyl) phosphate) and TEP (triethyl phosphate), without the plasticizing side effects associated with the aforementioned phosphates. Additionally, it has better powder flowability, making it easier for industrial production and processing.