Patent GB-911185-A (GB)
Title: Electrically conductive compositions
IPC: C09K23/00
Filed: 1958-12-30
Abstract: Aqueous emulsions or dispersions suitable for use as contact liquids in producing electrocardiograms or electroencephalograms comprise a water-insoluble surface active agent as dispersed phase, a water-soluble surface active agent as dispersing agent and a highly ionizable alkali metal salt in solution, the emulsion or dispersion being buffered to a pH of 4-8.  Specified waterinsoluble surface active agents are polyoxyalkylene derivatives of fatty acids having from 12-18 carbon atoms, fatty acid esters of sorbitol anhydrides (sorbitan monolaurate, monopalmitate and monooleate), glyceryl monostearate and methylene bis-stearamide which may form 10-11% of the composition. Specified watersoluble surface active agents are polyoxyalkylene sorbitan monolaurate, monopalmitate and monooleate, stearyl polyoxyethylamine and sodium lauryl sulphate which may form 1,6-1,7% of the composition.  In an example a blend of ethylene oxide derivatives of lanolin-higher fatty alcohols is used as a mixture of water-soluble and waterinsoluble surface active agent.  Specified salts are sodium chloride, potassium chloride and sodium sulphate which may be present in a concentration of 1-10% by weight.  In addition to the buffer (e.g. sodium phosphate/sodium acid phosphate or sodium citrate/citric acid), bacteria-, mould- or yeast-inhibitors such as esters of p-hydroxybenzoic acid, and preservatives e.g. acetic acid, glyceryl or cetyl alcohol, may be used.  In the examples sodium nitrite is also present and the compositions are pressurized with nitrogen.ALSO:Aqueous emulsions or dispersions suitable for use as contact liquids in producing electrocardiograms or electroencephalograms comprise a water-insoluble surface active agent as dispersed phase, a water-soluble surface active agent as dispersing agent and a highly ionisable alkali metal salt in solution, the emulsion or dispersion being buffered to a pH of 4-8. Specified water-insoluble surface active agents are polyoxyalkylene derivatives of fatty acids having from 12-18 carbon atoms, fatty acid esters of sorbitol anhydrides (sorbitan monolaurate, monopalmitate and mono-oleate), glyceryl monostearate and methylene bis-stearamide which may form 10-11% of the composition.  Specified water-soluble surface active agents are polyoxyalkylene sorbitan monolaurate, monopalmitate and mono-oleate, stearyl polyoxyethylamine and sodium lauryl sulphate which may form 1.6-1.7% of the composition.  In an example a blend of ethylene oxide derivatives of lanolin-higher fatty alcohols is used as a mixture of water-soluble and water-insoluble surface active agent.  Specified salts are sodium chloride, potassium chloride and sodium sulphate which may be present in a concentration of 1-10% by weight.  In addition to the buffer (e.g. sodium phosphate/sodium acid phosphate or sodium citrate/citric acid), bacteria-, mould- or yeast-inhibitors, such as esters of p-hydroxybenzoic acid, and preservatives, e.g. acetic acid, glycerol or cetyl alcohol, may be used.  In the examples sodium nitrite is also present and the compositions are pressurized with nitrogen.