| 摘要 |
<p>Method of manufacturing bladders for footballs or the like, comprising:… (a) applying a thin layer of a coating solution to one sinde of a polyurethane film capable of being formed into inflatible bladders, said film having a thickness of from 3 to 12 mils, said solution consisting essentially of a selected coating resin dissolved in an organic carrier solvent which does not dissolve or react with the polyyurethane film, said coating resin being selected from the class consisting of polyvinylidene polymers and copolymers of vinylidene chloride with other vinyl monomers ethylene vinyl alcohol polymers, and polyamide polymers, said coatin solution also containing from 3 to 18% by weight of an organic attack solvent miscible with said carrier solvent and which is capable of dissolving the polyurethane of said filing, said resin being present in a coating concentration;… (b) rapidly evaporating the solvent from said applied coating solution;… (c) optionally repeating said applying and evaporating steps, if required, the resulting dried coating comprising a resin layer fused with said polyurenthane film and having a thickness of from 0.3 to 1.2 mils; and… (d) forming said coated film into inflatible bladders with said coated layers on the outside thereof, whereby high air retention polyurethane bladders are provided which resist impact delamination.</p> |
