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AssigneeShirley Institute
InventorsJames R. Holker, Roy Jeffries, George R. Lomax
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Clothing weatherproofed by being coated with plastics material of low permeability to water vapor is uncomfortable to wear. The present invention provides a breathable polyurethane film for coating on fabrics to make them waterproof. The film comprises a hard segment formed by reaction of a low molecular weight difunctional compound with excess diisocyanate to form a prepolymer and a soft segment provided by polyethylene glycol with which the prepolymer is reacted in a stoichiometric amount. If desired the film can be formed by reacting the polyethylene glycol with excess diisocyanate to form a prepolymer which is then reacted with a stoichiometric amount of a low molecular weight difunctional compound. The mechanical properties of the film can be improved by cross linking with a cross linking agent such as a triisocyanate.
A breathable non-porous polyurethane film consisting of a block copolymer consisting of a low molecular weight difunctional compound to provide hard segments in the film, a polyethylene glycol to provide soft segments in the film and a diisocyanate, the polyethylene glycol being present in the amount of from 25 to 45% by weight based on the total weight of the film forming constituents, and said polyethylene glycol having an average molecular weight not exceeding 2000.
A breathable non-porous polyurethane film consisting of a block copolymer consisting of a low molecular weight difunctional compound to provide hard segments in the film, a polyethylene glycol to provide soft segments in the film and a diisocyanate,
A process for preparing a fabric consisting of a breathable non-porous polyurethane film comprising
A process for preparing a fabric coated with a breathable non-porous polyurethane film comprising
Dependencies are inferred from the claim text.