| 摘要 |
<p>A solder component preformed to the shape of the joint to be soldered has an integral coating of flux dispersed in a thermoplastic material. The latter may be polymethyl methacrylate, which may be plasticized with dibutyl phthalate or dioctyl phthalate and applied in a solvent such as toluol or xylol with or without alcohol; or nitrocellulose, which may be plasicized with dibutyl oxalate, tributyl citrate or camphor, ethyl acetate being used as solvent; or polymethyl methacrylate and nitrocellulose together; or polybutyl methacrylate in toluol; or polystyrene in xylol. Butyl oleate and a colouring material such as fluorescein may also be present. The flux may be sodium or potassium fluoride mixed with borax or boric acid or both; or zinc chloride. The solder may comprise 30 per cent silver, 25 per cent zinc, 25 per cent copper and 20 per cent cadmium; or 96 per cent tin and 4 per cent silver. Specification 646,377, [Group XXII], is referred to. According to the Provisional Specification, a similar flux may be applied to the surfaces to be joined and may contain butyl borate.</p> |
