Abstract: An adhesive system for preparing lignocellulosic composites comprising a) an aqueous primer composition and, b) a polyurethane adhesive composition, wherein said aqueous primer composition comprises: from 0 to 25 wt. %, by weight of the composition, of polyol selected from the group consisting of water soluble polyols, water dispersible polyols, water emulsifiable polyols and mixtures thereof, wherein said polyols have a molecular weight less than 5000 daltons; and, up to 10 wt. %, by weight of the composition, of surfactant selected from the group consisting of water soluble surfactants, water emulsifiable surfactants and mixtures thereof, with the proviso that the aqueous primer composition must comprise at least one of said polyol or a surfactant having hydroxyl functionality and a molecular weight of less than 5000 daltons.

Abstract: An adhesive system for preparing lignocellulosic composites comprising: a) a primer composition; and, b) a polyurethane adhesive composition, wherein said primer composition comprises: 1 to 100% by weight of the composition of at least one compound having a hydroxyl number of less than or equal to 30 mg KOH/g and being selected from the group consisting of polyalkylene glycols, polyalkylene glycol mono-ethers or polyalkylene glycol di-ethers; 0 to 99% by weight of the composition of solvent; and, 0 to 5% by weight of the composition of surfactant selected from the group consisting of water soluble surfactants, water emulsifiable surfactants and mixtures thereof. The adhesive system has particular applicability to wooden substrates characterized by high levels of water soluble extractives and, in particular, arabinogalactan.

Abstract: An adhesive system for preparing lignocellulosic composites comprising a) an aqueous primer composition and, b) a polyurethane adhesive composition, wherein said aqueous primer composition comprises: from 0 to 25 wt. %, by weight of the composition, of polyol selected from the group consisting of water soluble polyols, water dispersible polyols, water emulsifiable polyols and mixtures thereof, wherein said polyols have a molecular weight less than 5000 daltons; and, up to 10 wt. %, by weight of the composition, of surfactant selected from the group consisting of water soluble surfactants, water emulsifiable surfactants and mixtures thereof, with the proviso that the aqueous primer composition must comprise at least one of said polyol or a surfactant having hydroxyl functionality and a molecular weight of less than 5000 daltons.