Benzotriazoles and their production

摘要

Benzotriazoles of the general formula in which R is a straight- or branched-chain alkyl group containing 2-20 carbon atoms may be incorporated, as metal corrosion inhibitors in lubricants, hydraulic fluids, mineral oil compositions and anti-freeze mixtures such as aqueus ethylene glycol or other glycol-containing compositions. They may also be added to synthetic lubricant compositions which contain an antioxidant, e.g. dioctyl diphenylamine.ALSO:The invention comprises benzotriazoles of formula in which R is a straight or branched-chain alkyl group containing 2.20 carbon atoms. They may be produced by reacting a substituted 1,2-phenylenediamine of formula with nitrous acid or a compound capable of forming nitrous acid under the reaction conditions. The diamine used as starting material may be produced by the reduction of a nitroaniline of formula for example by catalytic hydrogenation. The nitroaniline, in turn, may be produced by nitration of a substituted aniline of formula for example, by treatment with nitric acid, preferably after protecting the amino group by converting it into an acylamino group.ALSO:Benzotriazoles of the general formula in which R is a straight or branched chain alkyl group containing 2-20 carbon atoms, may be used for treating metal surfaces to preserve them against corrosion or tarnishing. The compounds may be used in the vapour phase or as solutions, for example, in aqueous, glycol or polyglycol solvents and may be applied in any conventional manner, such as spraying on as a solution, immersing the metal in a solution or by wrapping the metal in packaging material containing the compound. Among the metals which may be treated are silver, iron and cadmium and thin alloys and, particularly, copper and its alloys. In addition the treatment of copper and its alloys with the benzotriazoles enable steam or other vapours to condense thereon as droplets and the compounds may thus be used to improve the heat transfer properties of copper and its alloys.ALSO:Benzotriazoles of the general formula in which R is a straight- or branched-chain alkyl group containing 2-20 carbon atoms may be used as metal deactivators to inhibit degradation of polymeric structures in contact with copper. For example, they may be incorporated into polypropylene material for use as covering material for copper wire or other copper articles.ALSO:A benzotriazole of formula in which R is an alkyl group containing 2-20 carbon atoms may be incorporated in paper.ALSO:Copper wire may be coated with polypropylene containing as stabiliser a benzotriazole of formula in which R is a straight- or branchedchain alkyl group containing 2-20 carbon atoms.