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US 12,522,687 B2Granted
Low free polyurethane prepolymer composition
AssigneeUrethane Systems USA LLC
InventorsRonald M. Emanuel, Jr., Polina Ware, Gerald King
Life of this patent
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Abstract
A polyurethane prepolymer composition may include more than 0 wt. % and less than 1.0 wt. % free diisocyanate monomer. The polyurethane prepolymer may include less than 80 wt. % of a 2:1 stoichiometric adduct of diisocyanate and at least one polyol (perfect prepolymer). Curable compositions may include such polyurethane prepolymer compositions and the such polyurethane prepolymer compositions may be used as adhesives.
Claims19
A polyurethane prepolymer composition, comprising:
- (a) a polyurethane prepolymer comprising, as a reaction product, (a1) an excess of 4,4′-methylene diphenyl diisocyanate and (a2) a polyol;
- and
- (b) free diisocyanate monomer in a range of from more than 0 to less than 1.0 wt. %, based on total polyurethane prepolymer weight,
- wherein an NCO content of the polyurethane prepolymer is in a range of from 5 to 7 wt. %,
- wherein the polyurethane prepolymer comprises less than 75 wt. % of a 2:1 stoichiometric adduct of the diisocyanate and the polyol, based on the total polyurethane prepolymer weight,
- wherein the polyol (a2) comprises (a2a) a first polypropylene glycol, having a weight average molecular weight Mw in a range of from 200 to 800 g/mol, and (a2b) a second polypropylene glycol, having a weight average molecular weight Mw of 800 to 2.000 g/mol.
3 more elements
Dependencies are inferred from the claim text.