No halogens, but plenty of rich color

are said to help overcome concerns sometimes voiced about such masterbatches’ effects on a part’s colors and mechanical characteristics. Unlike many other non-halogen flame retardants, which are based on organo-metallic chemistry, the flame retardant additives in these masterbatches do not contain solid particles that can make coloring difficult or expensive, and that can diminish physical properties.

They were developed specifically for use by processors of polyester, polypropylene (PP), and thermoplastic urethane (TPU). The masterbatches are marketed under the company’s CESA-flam brand. CESA-f/flam 5525NH is a halogen-free, flame-retardant masterbatch for polyesters.

It was designed to pass tests such as NFPA 701, MVSS 302, and UL 94 V-0. Potential applications include monofilaments, films, and injection molded parts. Typical dosage of the masterbatch is 6-8%. Some halogen-free masterbatches that rely on organo-metallic chemistry need to be dosed at very high levels, even above 20%. At the lower addition rates of these new masterbatches, it contributes only a slight yellow-gray coloration, claims the supplier, so that bright colors can be achieved in the end product more easily than with a more conventional non-halogen flame retardant.

The other new grade, CESA-flam CT-1629NH, is being marketed to processors of PP and TPU applications. This masterbatch is specifically designed to pass California’s TB 133 regulation for public seating and motor vehicle standard MVSS 302. Typical addition rates again are 6-8%. The masterbatch does not affect the color of the base resin in the part so, in most cases, coloring costs do not change. It is also inherently UV stable, says Clariant, so no additional UV additives are needed. —[email protected]