| 摘要 |
Cellular synthetic resin-metal compositions are produced from a mixture of a powdered metal and two incompatible thermoplastic resins, the mixture being shaped and then treated with a solvent which dissolves one of the resins but does not affect the other resin. The soluble thermoplastic resins are preferably water soluble such as polyethylene oxide, polyethylene glycol or polyvinyl pyrrolidone and the insoluble resins are polyethylene, polypropylene, polystyrene or polyvinyl chloride. The metal powders specified are silver, nickel, a mixture of nickel and silver, copper, a mixture of silver and palladium or a mixture of nickel and hydrated nickel oxide. The soluble resin is present in a proportion of 1/2 to 2 parts by weight of the insoluble resin and the mixing of the resins and metal is effected at about 275 DEG F. under pressure in a mixer, extruder or roll rubber mill. The mixture is shaped by extrusion or calendering at 225 DEG F., treated with water to dissolve the soluble resin and dried at below 180 DEG F. Specification 946,306 is referred to.ALSO:Sintered porous electrodes are produced from a mixture of a powdered metal and two incompatible thermoplastic resins, the mixture being shaped and then treated with a solvent which dissolves one of the resins but does not affect the other resin and finally sintered to remove the other resin. The soluble thermoplastic resins are preferably water soluble such as polyethylene oxide, polyethylene glycol or polyvinyl pyrrolidone and the insoluble resins are polyethylene, polypropylene, polystyrene or polyvinyl chloride. The metal powders specified are silver, nickel, a mixture of nickel and silver, copper, a mixture of silver and palladium or a mixture of nickel and hydrated nickel oxide. The soluble resin is present in a proportion of 1/2 -2 parts by weight of the insoluble resin and the mixing of the resins and metal is effected at about 275 DEG F. under pressure in a mixer, extruder or roll rubber mill. The mixture is shaped by extrusion or calendering at 225 DEG F., treated with water to dissolve the soluble resin, dried at below 180 DEG F., preheated in stages at 375-450 DEG F. and 450-550 DEG F. and finally sintered at 1100-1400 DEG F. For extruded tubes the preheating is effected on heated rollers which rotate the extruded tube. Specification 946,306 is referred to. |
