Polyurethane adhesive composition comprising a flame retardant package

Abstract

A polyurethane adhesive composition comprising a flame retardant package, wherein the flame retardant package comprises no more than about 20 wt % of the polyurethane adhesive composition, preferably no more than about 15 wt %, more preferably no more than about 10 wt %. Preferably the flame retardant package comprises a liquid phosphate ester based on the 5 weight of the composition, the liquid phosphate ester comprises no more than about 15 wt %, preferably less than about 10 wt %, more preferably no more than about 5 wt %, further preferably no more than about 4 wt %, even more preferred no more than about 3 wt %, and a solid ammonium polyphosphate, the solid ammonium polyphosphate comprising “n” number of ammonium phosphate units wherein “n” comprises at least about 500, further preferably at 10 least about 750, more preferably at least about 1000, even more preferably at least about 1500. The composition may comprise a polyisocyanate component and a polyol component and a molar ratio of the polyisocyanate component to the polyol component comprises more than about 1:1, preferably at least about 2:1, further preferably at least about 5:1, even more preferably at least about 10:1, and most preferably up to about 20:1. An advantageous 15 application of the adhesive composition is a structural adhesive, preferably for one or more wood substrates or to produce an engineered wood article.

Dependencies are inferred from the claim text.