Frothable polyurethane composition and a cellular foam produced therefrom suitable for use in joints between wallboards
AssigneeUnion Carbide Corporation
InventorsBruce P. Barth, Robert N. Johnson, Walter P. Mayer
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Abstract
Described herein is a frothable thermosetting polyurethane-forming composition, a process for producing a curable froth from said composition, a process for applying the curable froth to a substrate and a cured cellular polyurethane produced from the curable froth.
Claims38
A frothable thermosetting polyurethane-forming composition in which the density of the cured foam therefrom is essentially the same as the density of the uncured froth composition when cured such that at least one surface of the froth is exposed to the atmosphere, which composition comprises:
- (a) a polyol,
- (b) a polyisocyanate,
- (c) a thixotroping agent,
- (d) an inert gas, and
- (e) an amount of moisture available for reaction with the polyisocyanate that is less than that amount which would cause the composition to cure to a cellular polyurethane having a density which is not essentially the same density as that of the frothed composition.
A process for preparing a curable polyurethane froth which comprises adding separately and in fixed proportions an isocyanate and a polyol containing a thixotrope to a mixer, adding a gaseous material under pressure to the mixer to produce a froth, allowing the froth to expand in volume and to a density of from about 18 to about 45 lbs./ft..sup.3 by passing it from the mixer into a tube, which dispenses it onto a suitable substrate whereupon the froth is cured under ambient conditions.
A cured cellular polyurethane having an essentially closed cell structure, wherein the cells are essentially spherical and less than about 300 microns in diameter, and wherein the cells forming the surface of the polyurethane have a dimension which is essentially equivalent to the size in the mid-interior of the foam.
A process for concealing the joints between adjacent wallboard panels which comprises applying a curable polyurethane froth to said joint, whereupon the froth is cured, said froth having a density of from about 18 to about 45 lbs/ft.sup.3.
A monolithic appearing wall comprising at least two wallboard panels erected in substantially edge abutting relationship forming a joint therebetween, said joint being filled with a resilient cellular polyurethane having a density of from about 18 to about 45 lbs./ft..sup.3.
Dependencies are inferred from the claim text.