| 摘要 |
<p>699,415. Microporous rubber sheeting. DUNLOP RUBBER CO., Ltd. Oct 29, 1951 [Nov. 16, 1950], No. 28017/50. Classes 70 and 87 (ii). Microporous rubber sheeting is produced by casting a heat vulcanizable unfoamed rubber latex composition containing a gelling agent into the form of a sheet with solid ribs, gelling the sheet under conditions which prevent escape of water, permitting access of a fluid heating medium to the surface, and vulcanizing the gelled sheet by contact with a fluid heating medium under conditions preventing escape of water therefrom. In a preferred embodiment for the manufacture of microporous hard rubber battery separators a latex mix containing 30 to 40 parts of sulphur and 2 to 3 parts of calcium formate to every 100 parts of rubber is added from a jacketed tank 11 (Fig.l) onto a grooved belt 1 of rubber covered fabric which had pieviously been treated with an aqueous solution of coagulant such as aluminium sulphate. from tank 9. The latex layer is carried under spreader 12 and through gelling chamber 14 which is filled with saturated steam after which the sheet may be sprayed with water from means 26. The gelled sheet 28 after passing roll 3 is delivered onto preshrunk porous fabric 17 and the two together wound onto a stock reel 18, which is then vulcanized in an autoclave by steam at 40-80 lbs. pressure. For separators, the sheets may be 0.03 to 0.05 inches in thickness. Specification 698,613 is referred to.</p> |
