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US 4,048,104 AGranted
Polyisocyanate prepolymers from scrap polyester and polyurethane foam products obtained therefrom
AssigneeFreeman Chemical Corporation
InventorsGlenn R. Svoboda, John T. Suh, William L. Carlstrom, Gary L. Maechtle
Life of this patent
Estimating the term…
Abstract
Polyisocyanate prepolymers for use in preparing polyurethane products elastomers, adhesives and foams, are prepared by combining (1) organic polyisocyanate with (2) polyols which are the hydroxyl-terminated digestion products of (a) waste or scrap polyalkylene terephthalate polymers and (b) organic polyols. Polyurethane products resulting from the polyisocyanate prepolymers exhibit useful and unexpected properties.
Claims14
The method of preparing a polyisocyanate prepolymer comprising
- A. digesting polyalkylene terephthalate having a molecular weight greater than 15,000 in a reactive solvent selected from the class consisting of organic diols and triols having a molecular weight from 62 to 500 until the digestion product is soluble in acetone at room temperature;
- B. reacting the said digestion product with an organic polyisocyanate to produce a polyisocyanate-terminated prepolymer substantially free of unreacted hydroxyl radicals.
Dependencies are inferred from the claim text.