| 摘要 |
1,182,332. Polyglycol-clay compositions. MAGNAFLUX CORP. 17 March, 1967 [26 Oct., 1966], No. 12764/67. Heading C3R. [Also in Division C4] A composition in powder form to be used as a wet developer for an oil- or a water-based surface testing dye-containing penetrant composition comprises water-wettable but non-waterswelling clay particles of not more than 7Á a film-forming water-soluble solid polyethylene glycol having a viscosity at 210‹ F. of at least 100 sees. Saybolt, and a surfactant. Preferred developers contain 79-88% by wt. of clay, 2À9-5À5% polyethylene glycol and 1À5-2À6% surfactant, together with sodium nitrite as anticorrosion agent, E.D.T.A. sodium salt as sequestering agent, and sodium benzoate which acts both as an anti-corrosion agent and to aid dispersion when the E.D.T.A. salt is omitted. Preferred surfactants are sulphur- and chlorine free, and non-ionic, e.g. polyalkoxy alcohols, but alkyl aryl sulphonates are also suitable. For use, the powder is dispersed in water, aqueous ethanol or propanol, or another aqueous medium, and applied to the surface under test after prior application of the liquid penetrant. The surface is then dried and inspected for the presence of visible or fluorescent dye.
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