Process for the preparation of an aqueous emulsion composition of asphalt-polyurethane

Claim 1

A process for the preparation of an aqueous asphalt-polyurethane emulsion composition, comprising the following steps: (A) preparing an emulsion of an asphalt composition from (a) an asphalt composition prepared by adding, at a temperature of 100° to 150° C., 20 to 90 parts of asphalt to 5 to 80 parts by weight of a polyurethane extender selected from the group consisting of a polyethyleneglycol, a polypropyleneglycol, the copolymers of polyethyleneglycol or polypropyleneglycol, polyester polyethers and a hydroxytelechelic polybutadiene and (b) an aqueous phase obtained by solution in water of 1 to 20% by weight of an emulsifier selected from the group consisting of polyamine hydrochloride, an amido-amine hydrochloride and a quaternary ammonium salt, by heating the asphalt composition (a) to a temperature of 120° to 150° C. and emulsifying it with the aqueous phase (b) at a temperature of 40° to 80° C.; (B) preparing an unstabilized aqueous polyisocyanate emulsion by mixing, under strong agitation, 20 to 50 parts by weight of an organic polyisocyanate made up to 100 parts with water or a stabilized aqueous polyisocyanate by adding to said aqueous polyisocyanate emulsion a stabilizing amount of aqueous phase (b); and (C) mixing emulsions (A) and (B) in an amount of from 4 to 50 parts of polyisocyanate emulsion (B) per 100 parts of asphalt emulsion (A), if said polyisocyanate emulsion (B) is unstabilized and from 15 to 120 parts of polyisocyanate emulsion (B) per 100 parts of asphalt emulsion (A), if said polyisocyanate emulsion (B) is stabilized.