Process for producing flame-retardant pu foams

Abstract

The present invention describes a process for producing flame-retardant polyurethane foams. The process of the invention includes the use of hyperbranched, nitrogen-containing polymers for providing flame retardancy to polyurethane foams. The amounts used of the hyperbranched compounds are preferably from 5 to 20% by weight, based on the polyol component. The N content of preferred nitrogen-containing compounds is at least 2% by weight. The N content of the polyurethane foams of the invention is from 1 to 8% by weight from the hyperbranched polymer. Compounds in particular used are hyper-branched polyureas, hyperbranched polyamides, and in particular hyperbranched polylysines, hyperbranched polyisocyanurates, and hyperbranched polyesteramides. An advantage of the use of the compounds of the invention is that the polyurethane foams can be rendered flame-retardant without the use of, or by using markedly reduced amounts of, halogen-containing flame retardants. It is likewise possible to achieve a marked reduction in, or to avoid, the use of additive, halogen-free flame retardants. The processing profile and the mechanical properties of the polyurethane foams are thus significantly improved. The compounds of the invention are preferably used in such a way that the foams are rendered flame-retardant without use of halogen. The hyperbranched polymers of the invention can provide flame retardancy either to flexible polyurethane foam or to rigid polyurethane foam.

Dependencies are inferred from the claim text.