GB1328509A - Inhibition of corrosion - Google Patents

Abstract

1328509 Inhibiting corrosion NATIONAL RESEARCH DEVELOPMENT CORP 27 Nov 1970 [18 Dec 1969] 61748/69 Heading C7E [Also in Division C4] A composition for the inhibition of corrosion in a saline environment, e.g. the ballast tanks or bilges of ships, comprises a water-soluble polyphosphate or a mixture of polyphosphates, the greater part of which is water-soluble, and one or more surfactants selected from where R is a saturated or unsaturated C 8 -C 24 alkyl radical, R 1 is C 1 -C 6 alkyl, R 2 , R 3 , are H or C 1 -C 6 alkyl, X = a salt-forming radical, n = 2-10, a, b = 1-3 and a + b = 4, and c, d, e = 0 to 10, at least one of c, d, e, not being 0. A composition for reducing corrosion of motor vehicles when used as a de-icer or dust-laying agent for roads comprises a mixture of NaCl or CaCl 2 with the above composition; this latter must contain Ca or Zn ions, the normal Ca content of rock salt being sufficient without further Ca addition. The polyphosphates may be those of Na, K, NH 4 , or Ca, particularly (NaPO 3 ) n where n = 6-20. The group R in the surfactant may be derived from natural products such as tall oil or soyabean oil; salts of the above compounds I to III such as the hydrochloride or sulphate may be used. The weight ratio polyphosphate : surfactant is preferably 10:1 to 2:1, and in the de-icer there may be 0À1-10% w/w polyphosphate relative to the NaCl or CaCl 2 and 0À02-2% surfactant. Water, organic solvents, and/or wetting agents may be present.