| 摘要 |
757,645. Ammunition cartridges. OLIN MATHIESON CHEMICAL CORPORATION. May 3, 1954 [May 25, 1953], No. 12772/54. Class 9(1) An aluminium cartridge case is provided having a non-metallic coating interposed between the case and the short charge. The coating may be a natural resin or synthetic resins such as ethyl cellulose, phenol formaldehyde, polystyrene, polyesters or epoxy may be used. Alternatively films of nitrocellulose lacquer or waxes such as paraffin wax, micro-crystalline wax, carnauba wax or ceresin wax may be applied by dipping or spraying. Preferably the coating has a melting point above 120‹F. Coatings of aluminium oxide or aluminium fluoride may be applied to the inner wall of the case, preferably by an anodic process. In one embodiment the lead shot are tumbled in a solution of microcrystalline wax dissolved in carbon tetrachloride until a wax film 10 to 20 microns thick is formed on the shot. In a second embodiment the aluminium case is immersed in a sodium hydroxide solution at 180‹F., then rinsed in water and anodized in a sulphuric acid solution. After rinsing in water, the case is then immersed in a nickel acetate solution at 200 ‹F. and again rinsed in water before being air dried.
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