Process for preparing elastomeric polyurethane or polyurethane-urea polymers, and polyurethanes so prepared
AssigneeThe Dow Chemical Company
InventorsJames R. Porter, Robert B. Turner
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Abstract
A process is disclosed for preparing a polyurethane or polyurea elastomer by reacting in a closed mold a reaction mixture comprising a polyisocyanate and a relatively high equivalent weight polyether. The process is characterized by employing as said polyether a polymer or copolymer of propylene oxide having at least two hydroxyl groups per molecule, an equivalent weight from about 1000 to about 5000 and a monofunctional species content of about 0.04 milliequivalents/gram of polymer or less.
Claims26
A process for preparing a polyurethane and/or polyurea elastomer wherein a polyisocyanate is reacted with an isocyanate-reactive composition including a 1000-5000 equivalent weight material, wherein at least the major portion of the 1000-5000 equivalent weight material is a poly(propylene oxide) polymer nominally having at least two isocyanate-reactive groups per molecule or mixture thereof, said poly(propylene oxide) polymer or mixture thereof having about 0.04 milliequivalent per gram (meq/g) or less of monofunctional impurities.
A process wherein an isocyanate-terminated prepolymer or quasi-prepolymer is reacted with an isocyanate-reactive composition to form a polyurethane and/or polyurea elastomer, wherein
- (1) said prepolymer or quasi-prepolymer is the reaction product of an excess of a polyisocyanate and a composition containing a 1000-5000 equivalent weight isocyanate-reactive material or mixture thereof, wherein at least the major portion of said 1000-5000 equivalent weight isocyanate-reactive material is a poly(propylene oxide) polymer nominally having at least two isocyanate- reactive groups per molecule or mixture thereof, said poly(propylene oxide) polymer or mixture thereof having about 0.04 meq/g or less of monofunctional impurities:
- and
- (2) said poly(propylene oxide) polymer or mixture thereof constitutes at least about 15 percent of the combined weight of all 1000-5000 equivalent weight isocyanate-reactive materials employed in preparing said prepolymer or quasi-prepolymer and in the isocyanate-reactive composition with which said prepolymer or quasi-prepolymer is reacted.
Dependencies are inferred from the claim text.