Reference

Composition and method for simultaneously removing iron and copper scales from ferrous metal surfaces

Composition and method for simultaneously removing iron and copper scales from ferrous metal surfaces. Lawson, Michael Beau; Martin, Larry Dale (Halliburton Co., USA). Eur. Pat. Appl. EP 104012 A2 28 Mar 1984, 18 pp. DESIGNATED STATES: R: DE, FR, GB, IT, NL. (English). (European Patent Organization). CODEN: EPXXDW. CLASS: IC: C23G001-08. APPLICATION: EP 83-304969 26 Aug 1983. PRIORITY: US 82-420998 21 Sep 1982. DOCUMENT TYPE: Patent CA Section: 55 (Ferrous Metals and Alloys) Cleaning compns. for boiler tubes encrusted with Fe3O4, Fe2O3, CuO, and Cu contain org. chelating acids which dissolve Fe (hydroxyacetic acid (I) [79-14-1] and formic acid (II) [64-18-6]), reducing agents such as erythorbic acid and its alkali metal and NH4 salts, and a Cu-complexing compd. such as thiourea [62-56-6] or hexahydropyrimidine-2-thione (III) [2055-46-1]. The soln. is used at 24-66°. Thus, a cleaning soln. contained I 2 wt.%, II 1 wt.%, 0.1 vol.% of a corrosion inhibitor contg. naphtha 15, ethylene glycol [107-21-1] 40, dibutylthiourea [109-46-6] 8, acetic acid [64-19-7] 12, alkyl pyridine 10, ethoxylated alc. 10, and ethoxylated amine 5 wt.%, Na erythorbate (IV) [6381-77-7] 2 wt.%, and 1% of a Cu complexer contg. III 60 and thiourea 40 wt.%. Magnetite 2 and Cu powder 0.1 g and an AISI 1020 [12725-36-9] mild steel coupon are added and the soln. is heated at 60° for 6 h. The magnetite dissoln. was 18.15% and the Cu dissoln. was 0.0247%, compared to 1.45 and 0.0010%, resp. in a soln. with no IV and no Cu complexer.

Rapid analysis of lubricating oil additives by normal-phase and adsorption high performance liquid chromatography

Rapid analysis of lubricating oil additives by normal-phase and adsorption high performance liquid chromatography. Musha, Kiyoshi; Nagata, Chikakiyo; Tanaka, Shigeyuki (Asahi Denka Kogyo K. K., Tokyo 116, Japan). Bunseki Kagaku, 34(3), T40-T44 (Japanese) 1985. CODEN: BNSKAK. ISSN: 0525-1931. DOCUMENT TYPE: Journal CA Section: 51 (Fossil Fuels, Derivatives, and Related Products) Section cross-reference(s): 80 Normal-phase and adsorption high-performance liq. chromatog. (gradient elution, with iso-PrOH and hexane on Zorbax NH2 and Zorbax SIL columns) of lubricating oil additives are described. Additives studied are 16 alkyl- and arylphenols, 6 arom. amine derivs., 5 benzothiazole, benzimidazole, and benzotriazole derivs., 1,3-diethylthiourea [105-55-5], 1,3-dibutylthiourea [109-46-6], 1,3-didodecylthiourea [7505-51-3], diphenylguanidine [102-06-7], 6 phthalate derivs., ditridecyl 3,3'-thiodipropionate [10595-72-9], tetramethylthiuram disulfide [137-26-8], tetraethylthuram disulfide [97-77-8], tetrabutylthiuram disulfide [1634-02-2], Ni dithiocarbamate [13985-94-9], and di-m-sulfidobis[oxo(di-2-ethylhexyldithiocarbamato)Mo(V)] [90901-24-9]. The results were compared with those obtained by reversed-phase high-performance liq. chromatog.