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US 5,391,343 AGranted
Thin-walled articles of polyurethaneurea
AssigneeE. I. Du Pont de Nemours and Company
InventorsRichard L. Dreibelbis, Nathan E. Houser, Jacob Lahijani
Life of this patent
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Abstract
Certain polyether-based or polyester-based polyurethaneureas in solutions of organic solvent at a 12 to 20% concentration are particularly suited for use in a mandrel-dipping process for producing thin-walled elastic articles, such as surgical gloves, which are more resistant to puncture and tear than conventional surgical gloves made from rubber latex.
Claims2
A process for fabricating a thin-walled elastic article comprising
- preparing a polyetherurethaneurea by reacting methylene-bis(4-phenylisocyanate) with a polyether diol derived from a homopolymer of tetrahydrofuran or a copolymer of tetrahydrofuran and 3-methyltetrahydrofuran in a weight ratio in the range of 96/4 to 80/20, said polyether diol having a number average molecular weight in the range of 3,000 to 6,000, to form an isocyanate-capped prepolymer having an isocyanate group content in the range of 1.4 to 2.0 weight %, and
- then chain-extending the isocyanate-capped prepolymer with ethylenediamine or 1,3-diaminocyclohexane to form the polyetherurethaneurea,
- forming a solution of the polyetherurethaneurea in an organic solvent that is substantially free of metal chlorides, the polyetherurethaneurea being present in the solution at a concentration in the range of 12% to 20% by total solution weight, and the solution having a viscosity, measured at 30.degree. C., in the range of 25 to 125 poise,
- degassing the thusly formed polyetherurethaneurea solution,
- dipping a mandrel into the solution and then
- removing the mandrel therefrom to form a solution-coated mandrel,
- drying the coated mandrel and
- removing the resulting dried thin-walled article from the mandrel.
5 more elements
Dependencies are inferred from the claim text.