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US 5,104,693 AGranted
Polyurethane carpet-backing process based on soft segment prepolymers of diphenylmethane diisocyanate (MDI)
AssigneeThe Dow Chemical Company
InventorRandall C. Jenkines
Life of this patent
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Abstract
Polyurethane-backed substrates such as attached cushion carpeting are prepared from a polyurethane forming composition based on a soft segment prepolymer of MDI or an MDI derivative. The use of the prepolymer provides a backing having good strength properties and good resiliency.
Claims7
In a process for preparing a polyurethane-backed substrate wherein an uncured polyurethane-forming composition is applied to a surface of the substrate, gauged and cured to form an adherent backing thereto, the improvement comprising employing a polyurethane-forming composition containing
- (A) at least one isocyanate-reactive material having an average equivalent weight of about 1000 to about 5000,
- (B) an effective amount of a blowing agent, and
- (C) a polyisocyanate in an amount to provide an isocyanate index of about 90 to about 130, wherein at least 30% by weight of such polyisocyanate is a soft segment prepolymer which is the reaction product of a stoichiometric excess of diphenylmethane diisocyanate (MDI) or a derivative thereof and an isocyanate-reactive organic polymer having an equivalent weight from about 500 to about 5000, said prepolymer having an NCO content of about 10 to about 30% by weight.
Dependencies are inferred from the claim text.