US Patent 7736702 Method of making a coated airbag

Coating compositions, which are used as a monolithic coating layer for airbags. The coating compositions include a combination of urethanes which are blended together. At least one of the urethane components provides gas-retaining properties and the other provides the aging stability. The gas-retaining urethane may be characterized as having high tensile strength at break, high elongation at break, and a 100% modulus less than 1,200 psi. The aging stability urethane has a polycarbonate backbone as result of a manufacturing process in which a polycarbonate diol is reacted with an isocyanate. The resulting coating compositions, when applied as a single layer to an airbag fabric, result in an airbag with good gas retention and aging stability.