New flame retardants for NOP-based foams

Clariant says it is supporting the use of green chemistry to create fire retarded polyurethane foams for the upholstery sector. The Muttenz-based Swiss supplier of speciality chemicals cites research carried out by Green Urethanes Ltd confirming that manufacturers can use Clariant’s halogen-free flame retardant Exolit OP 560 with this technology to develop low emission flexible foams that meet internationally accepted flammability standards such as Cal TB 117. Clariant says that reactice phosphonate liquid flame retardant addresses concerns by eliminating unwanted emissions. The grade chemically reacts into the PU foam polymer and therefore does not migrate and remains fixed within a foam formulation, also resulting in reduced amounts of volatile organic compounds (VOCs).

The phosphonate’s high effectiveness and high polymer compatibility allows it to be used at low dosage in the foam matrix, which adds to its overall sustainability. By applying Green Urethanes’ unique processing characteristics, the amount of flame retardant required for flexible foam to pass the smolder and open flame tests in California TB 117 is reduced by 80 %. Further benefits for PU applications include very good ageing stability, low smoke density and smoke gas corrosivity, and good recyclability.
Green Urethane’s Technology is already available in the US market and uses natural oil polyols (NOP) to produce a range of standard foams for the North American bedding and furniture industries. These foams have a total bio-renewable content of approximately 35 % by weight.

Jeff Rowlands, Director of Green Urethanes Limited comments: “By using these advances in Green Chemistry, the original safety objectives of Cal TB 117 are still being met; but now with the added assurance that it comes with long-term environmental protection from undesirable emissions. These are positive developments for the upholstery sector and also provide a route to reducing the environmental impact of all foam types, including those made for uses which do not need to meet the Cal TB 117 test criteria.”