Solvent-free, organoclay-filled asphaltic polyurethane dispersion and method of making and using it
First Claim
1. A substantially solvent-free adhesive dispersion of asphalt microdispersed in a liquid polyurethane prepolymer, comprising, a substantially anhydrous, stable, moisture-curable blend of asphalt microdispersed as a dispersed phase within a continuous phase of a liquid polyurethane prepolymer, said dispersed phase consisting of asphalt particles in the size range from 1 μ
- m to 100 μ
m having essentially no functional groups reactive with a functional group of said liquid prepolymer, said particles comprising asphalt and an organoclay having platelets which have a quaternary ammonium ion ionically bonded to their surfaces, said organoclay being present in an amount in the range from 0.05 to 10 parts per 100 parts of said asphalt blend, whereby said adhesive dispersion is stable without being cured when stored under essentially anhydrous conditions at a temperature in the range from about -20°
C. to 75°
C., and after storage is flowable at ambient conditions.
2 Assignments
0 Petitions
Accused Products
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 μm-44 μm) 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.
68 Citations
11 Claims
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1. A substantially solvent-free adhesive dispersion of asphalt microdispersed in a liquid polyurethane prepolymer, comprising, a substantially anhydrous, stable, moisture-curable blend of asphalt microdispersed as a dispersed phase within a continuous phase of a liquid polyurethane prepolymer, said dispersed phase consisting of asphalt particles in the size range from 1 μ
- m to 100 μ
m having essentially no functional groups reactive with a functional group of said liquid prepolymer, said particles comprising asphalt and an organoclay having platelets which have a quaternary ammonium ion ionically bonded to their surfaces, said organoclay being present in an amount in the range from 0.05 to 10 parts per 100 parts of said asphalt blend, whereby said adhesive dispersion is stable without being cured when stored under essentially anhydrous conditions at a temperature in the range from about -20°
C. to 75°
C., and after storage is flowable at ambient conditions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- m to 100 μ
Specification