| 摘要 |
770,730. Fibre board battery - separators. UNITED STATES RUBBER CO. May 31, 1955 [Aug. 31, 1954], No. 15532/55. Class 96. A separator for an electric accumulator is made from a bibulous sheet 1 of uniform formation, e.g. 0.015 to 0.06 in. thick, embossed &c. with ridges 2, and having an air permeability (Gurley 5 oz. cylinder) of 4 to 19 secs., and having at least 90 per cent of alpha cellulose fibres, e.g. cotton linters impregnated with a C-stage phenol-formaldehyde resin mixed with a non-ionic surface-active agent which is either a polypropylene glycol of mol. weight 1250 or an up to 60/40 product of condensation of ethylene oxide with a polyoxypropylene base and having a mol. weight of 890 to 3600. The resin may be applied at the A-stage and cured. Specifications 700,665, 700,666 and 770,241 are referred to. |
