Method for preparation of 5-alkylsalicylaldoximes and application thereof

Abstract

Method for preparation of 5-alkylsalicylaldoximes with formula 1, where R is a C6-C16 alkyl group, consisting in that into a water-alcohol solvent system, p-alkylphenol, sodium hydroxide, chloroform and hydroxylamine are introduced, while in relation to the alkylphenol used, sodium hydroxide and chloroform are used in amounts from the stoichiometric amount to a 100% excess, and hydroxylamine is used in amounts from the stoichiometric amount to a 60% excess, and the reaction is carried out at a temperature of 60-75° C. for 1.5-4 h, and then, at a temperature of 20-30° C., the post-reaction mixture is acidified till the pH of the aqueous phase <7.0 is obtained, and next, an alcohol-water azeotrope is distilled off with an admixture of unreacted chloroform, the residue is mixed with a neutral C5-C10 hydrocarbon solvent, the layers are separated, and the solvent is distilled off from the organic phase.

What is claimed is: 
     
         1 . Use of a product as a corrosion inhibitor and a means of enhancing plasticity and adhesion of paint coatings, the product by a method for preparation of 5-alkylsalicylaldoximes with formula 1, 
       
         
           
           
               
               
           
         
         wherein R is a C 6 -C 16  alkyl group, using the Reimer-Tiemann reaction, wherein into a water-alcohol solvent system, p-alkylphenol, sodium hydroxide, chloroform and hydroxylamine are introduced, while in relation to the alkylphenol used, sodium hydroxide and chloroform are used in amounts from the stoichiometric amount to a 100% excess, and hydroxylamine is used in amounts from the stoichiometric amount to a 60% excess, and the reaction is carried out at a temperature of 60-75° C. for 1.5-4 h, and then, at a temperature of 20-30° C., the post-reaction mixture is acidified until the pH of the aqueous phase <7.0 is obtained, and next, an alcohol-water azeotrope is distilled off with an admixture of unreacted chloroform, the residue is mixed with a neutral C 5 -C 10  hydrocarbon solvent, the layers are separated, and the solvent is distilled off from the organic phase. 
       
     
     
         2 . The use according to  claim 1 , wherein a solution of the product in a concentration of 5-30% is used in a solvent selected from: C 2 -C 4  alcohols, ethers, ketones, aliphatic hydrocarbons, aromatic hydrocarbons, preferably in ethanol, isopropanol, toluene, xylene, chloroform, hexane or 1,1,1-trichloroethane, optionally in the mixture of the selected solvents mentioned above. 
     
     
         3 . The use according to  claim 2 , wherein the product is applied directly onto a metal surface after it has been cleaned from loose mineral impurities, the product being used as a prime coat before the application of a coating system.