| 摘要 |
Compositions for cleaning metal prior to painting, enamelling, or the like contain a rust-removing agent, a solvent of oil or grease, and a wetting agent containing a sodium salt of the acid sulphates of multiple carbon saturated branched chain secondary alcohols of the formula <FORM:0484571/III/1> in which R and R1 are aliphatic hydrocarbon radicals and R + R1 have a total content of 6-17 C. atoms. A suitable composition is 15-70 vol. of 75 per cent ortho-phosphoric acid, 15-30 vol. of mono-butyl ether of ethylene glycol, 1/8 -2,0 vol. of a 25 per cent solution in water of the sodium salts having 14 or 17 carbon atoms in the molecule and water; for use this is diluted with water to the strength desired. Molasses or other sugary material may be added to raise the viscosity. Up to 80 per cent of the above butyl ether may be replaced by methyl-ethyl ketone or similar solvent of grease, and all or part may be replaced by the mono-ethyl or other ether of ethylene glycol or by an acetate of ethylene glycol.
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