Polyurethane with polyether and polyester blocks and alkoxysilane end group

摘要

Preparation of a polyurethane with polyurethane-polyether and polyurethane-polyester blocks, comprises (i) reaction of a mixture of alcohols comprising a polyether polyol with a stoichiometric excess of an aliphatic diisocyanate, to form a polyurethane-polyether block possessing at least 2 isocyanate end groups, then (ii) reaction of the polyurethane from step (i) with a stoichiometric excess of a polyester polyol and then (iii) reaction of the polyurethane with the hydroxy end group from step (ii) with a stoichiometric amount of an isocyanatosilane. Preparation of a polyurethane with polyurethane-polyether and polyurethane-polyester blocks comprising at least 2 end blocks each consisting of a polyurethane-polyester block joined to an alkoxysilane end group, comprises (i) reaction of a mixture of alcohols comprising a polyether polyol with a stoichiometric excess of an aliphatic diisocyanate, to form a polyurethane-polyether block possessing at least 2 isocyanate end groups, then (ii) reaction of the polyurethane from step (i) with a stoichiometric excess of a polyester polyol, to form a polyurethane with polyurethane-polyether and polyurethane-polyester blocks comprising at least 2 end blocks each consisting of a polyurethane-polyester block joined to a hydroxy end group, and then (iii) reaction of the polyurethane with the hydroxy end group from step (ii) with a stoichiometric amount of an isocyanatosilane. Independent claims are included for: (1) the polyurethane with polyurethane-polyether and polyurethane-polyester blocks, obtained by the above method; (2) an adhesive composition comprising the polyurethane and 0.01-3% of a crosslinking catalyst; and (3) assembly of 2 substrates, comprising melting the adhesive composition by heating at 30-120[deg] C, then coating it, in the form of a layer of thickness of 0.3-5 mm, on at least one of the 2 surfaces belonging respectively to the 2 substrates to be assembled and which are intended to be brought into contact with one another during assembly on a faying surface, and then, without exceeding a period of time corresponding to the maximum open assembly time of the adhesive composition, bringing the 2 substrates into effective contact on their faying surface.