Solvent-free, organoclay-filled asphaltic polyurethane dispersion and

Abstract

An organoclay in which a quaternary long chain fatty amine is ionically bonded to clay platelets is found to function both as a filler or thickener as well as a compatibilizer in an asphaltic polyurethane (PUR) dispersion. When a PUR prepolymer is mixed into a homogenized blend of asphalt and organoclay under high shear, a phase inversion occurs the result of which is that a microdispersion of asphalt particles (preferably 1 .mu.m-44 .mu.m) becomes the dispersed phase which is uniformly scattered throughout the PUR prepolymer (the continuous phase). This dispersion is found to be an excellent adhesive, particularly for roofing components which can be secured without using conventional fasteners, and it is stable and moisture-curable to afford, when cured, an elastomer having excellent adhesion to surfaces exposed outdoors. It is also user-friendly because it is solvent-free. The asphalt is treated to react all functional groups it may have because they may react with a functional group of the PUR prepolymer. The organoclay compatibilizer may be supplemented with a compatibilizer used in the parent case where the viscosity of the dispersion is to be lowered, and to save on the cost of making the dispersion. A sprayable adhesive dispersion may be formed by diluting the organoclay compatibilized dispersion with a plasticizer which, together with the asphalt and organoclay, becomes an integral part of the elastomer when the PUR is cured.