Patent GB-523451-A (GB)
Title: Stabilization of organic materials in the presence of copper
IPC: C10L1/14
Filed: 1938-12-29
Abstract: 523,451. Preserving food. DU PONT DE NEMOURS & CO., E..I. Dec. 29, 1938. No. 37753. Convention date, Dec. 29, 1937. [Classes 14 (ii) and 49 [Also in Groups IV and III] The deterioration of organic compounds particularly mineral hydrocarbons due to the action of oxygen in the presence of copper and its compounds is retarded by the addition of an arylidene amine prepared by condensing an aromatic, ortho-hydroxy substituted aldehyde with a polyamine which is an aliphatic amine containing at least two primary amino groups attached to different carbon atoms of the same open chain, and which may contain aromatic or other cyclic groups substituted on the chain. The aldehyde is used in such a proportion that each amine group of the polyamine is condensed with an aldehyde group. The compounds of the present invention are essentially " copper deactivators" and are not specific to any particular type of organic material but are independent of the organic substance provided it is not so strongly acid as to destroy the copper deactivator compound. The aldehyde may contain as substituents alkoxy, aryloxy, halogen, heterocyclic, amino, nitro, cyano, carboxyl and sulphonic groups as well as hydroxy, alkyl and aryl radicals. The polyamine may also be substituted but is preferably unsubstituted. Aldehydes mentioned include 2-hydroxybenzaldehyde, 2-hydroxy 5-chlorbenzaldehyde, 2- hydroxy-3:5-dibromobenzaldehyde 2-hydroxy- 3-nitrobenzaldehyde, 2-hydroxy-6-methylbenzaldehyde, 2-hydroxy-3-methoxybenzaldehyde, 2:4-dihydroxybenzaldehyde, 2:6-dihydroxybenzaldehyde, 2-hydroxy-3-cyanobenzaldehyde, 2- hydroxy-3-carboxybenzaldehyde, 2-hydroxybenzaldehyde-3-sulphonic acid, 2-hydroxynaphthaldehyde-1, 1-hydroxynaphthaldehyde-2, anthrol-2-aldehyde-1, 4-hydroxydiphenyl-aldehyde-3, 3-hydroxyphenanthrene-aldehyde-4, 1:3-dihydroxy- 2:4-dialdehydebenzene, 4-hydroxyquinoline - aldehyde - 3, 4 - hydroxyquinoline-aldehyde-8. Amines mentioned include methylene diamine, ethylenediamine, 1:2-propylenediamine, 1:3 propylenediamine, 1:10- decylenediamine, diethylenetriamine, triethylenetetramine, tetra (aminomethyl) methane. The reaction may take place without a solvent or in the presence of a solvent such as water, methyl, or ethanol. The preferred compound is di-(2-hydroxybenzal)-ethylenediamine. The copper deactivators are added in amounts which depend on the amount of copper present in the organic compound to be treated usually from 0.0002 per cent. to 0.01 per cent. The compounds are used in addition to the normal antioxidants and their function appears to be to keep the copper from rendering the antioxidant inoperative, and to make unnecessary the use of large amounts of antioxidant. The compounds of the present invention may be added to a number of different organic materials of which there are mentioned petroleum products and mineral hydrocarbons such as petrol, kerosene, fuel oil, transformer oil and lubricating oil ; fats ; waxes ; animal and vegetable oils and fats, and derivatives obtained therefrom such as soap ; sulphonated and sulphated oils, including alcohol sulphates ; fruit and vegetable juices ; essential oils ; perfumes such as natural and synthetic irone, neroli oil and jasmine oil; cotton ; silk ; paper ; wool ; cellulose acetates ; and regenerated cellulose products.