| 摘要 |
1,113,942. Primary cell depolarizer mixture. GESELLSCHAFT ZUR FORDERUNG DER FORSCHUNG DER EIDGENOSSISCHEN TECHNISCHEN HOCHSCHULE. 25 May, 1965 [26 May, 1964], No. 22177/65. Heading H1B. A depolarizer body for a primary cell is prepared by precipitating silver oxide from aqueous silver nitrate solution with aqueous sodium hydroxide, reducing it with formaldehyde to form silver particles of 0À01-0À04 mm. size, washing and drying the powder and mixing 5 weight per cent of it with 95 weight per cent of a mercuric oxide depolarizer mixture in benzene, evaporating the benzene and pressing the mixture into the desired shape. A primary cell contains such a depolarizer body and a porous zinc anode separated by a diaphragm. Zinc having a pore volume over 50% is preferred for the anode. Suitable separators may be prepared by stretching flat over a smooth horizontal plate, e.g. of glass, a thin fleece or fabric of 1000/2000 mesh/square inch, e.g. of cellulose, synthetic fibre, or glass fibre, and impregnating this with a 10% solution of acetyl cellulose in 90/10 methylene dichloride/ethanol, optionally adding plasticizer, e.g. dimethyl phthalate, then drying and saponifying for 50 hours at 90‹ C. in 30% NaOH; alternatively the fabric may be treated with 10% polyvinyl alcohol in water, followed by 10% formaldehyde and 1% HCl in water. In the example the depolarizer mixture comprises 94.2 p.b.w. HgO and 0.8 p.b.w. polystyrene binder. |
