Ketone-amine condensation products and derivatives thereof.-The reaction product of a ketone and an aromatic amino compound, or derivatives of such reaction products, are used to retard the deterioration of rubber. The reaction product may be made with or without the aid of a dehydrating agent of which the following are specified: calcium chloride, iodine, sulphanilic acid, phosphorus pentoxide, sodium hydroxide, magnesium perchlorate, acetic acid, barium oxide, zinc chloride, sulphuric acid, or the zinc chloride double salt of the amine. It is stated that different compounds may be obtained by the reaction in relative amounts which may vary with the duration of heating and the dehydrating agent employed. Thus sulphanilic acid tends to give more highly condensed products than iodine or calcium chloride. The derivatives include aldehyde derivatives, sulphur derivatives such as are formed by the action of sulphur, carbon disulphide, sodium polysulphides or sulphur chlorides on the reaction product, nitroso derivatives, formic acid derivatives, and naphthol addition products. The preparation of the following products is either described in examples or otherwise referred to: (1) Ketone-amines: acetone-aniline, acetone-phenylhydrazine, acetone-p,p1-diaminodiphenylmethane, acetone-diphenylamine, acetone-diphenyl formamidine, mesityl oxide-aniline, diacetone alcohol-aniline, acetone-phenyla -, or b - naphthylamine, acetone - a - naphthylamine, acetophenone-aniline, cyclohexanone-aniline, formaldehyde acetone condensation product-aniline, mesityl oxide-phenyl-, a - or b -naphthylamine, acetone-triphenylmelamine, acetone - di - o - tolylguanidine, acetone-diphenylguanidine, acetone-p,p1-dinaphthylaminodiphenylmethane, acetone-monoethylaniline, tetramethyldiamidobenzophenone-aniline, acetone-o-tolylbiguanide, acetone-diphenyldiaminoethane, methylethyl-ketone-p,p1-diaminodiphenylmethane, ethylideneacetone-p,p1-diaminodiphenylmethane, acetone-mixture of b -naphthol and aniline, acetone-mixture of phenol and aniline, monochloroacetone-aniline, acetonetoluidines, acetaldolacetone-diphenylamine, acetonediphenylethylenediamine, methylethylketone-diphenylamine, methylethylketone-phenyl - a - naphthylamine, acetone-o-tolylguanidine. Instead of these ketones there may be used-phorone, diethylketone, benzophenone, dichloracetone, aldol acetone, allylacetone, benzalacetone, diacetyl, acetylacetone, acetonylacetone, salicaldehyde acetone, furfuralacetone. The term ketone also includes thioketones and ketone dihalides and is further defined as meaning compounds containing one or more keto groups but containing no carboxylic acid or ester groups. Instead of the amines mentioned there may be used monochloranilines, o-, m-, or p-toluidine, xylidines, b -naphthylamine, aminodiphenyls, dinaphthylamines, asymm - diphenylhydrazine, diaminodiphenyl sulphide, diaminodiphenyl polysulphides, diaminodinaphthyl sulphides, p-aminobenzylaniline, dinaphthyldiaminoethane, ditolyldiaminoethane, p-amino-p1-naphthylaminodiphenylmethane, p.p1-diaminodiphenyldimethylmethane, p.p1-dinaphthylaminodiphenyldimethylmethane, phenyl-b -naphthylguanidine, phenyl-o-tolylguanidine, di-o-tolylbiguanide, monophenylbiguanide, diphenylbiguanide, and diphenylacetamidine. (2) Aldehyde derivatives: formaldehyde, acetaldehyde aldol, butyraldehyde, crotonaldehyde, or heptaldehyde-acetone-aniline, formaldehyde-chloracetone-aniline, formaldehyde-acetone-diphenylamine, butyraldehyde-acetone-diphenylamine. (3) Sulphur derivatives: sulphur derivative of acetone-diphenylamine. (4) Nitroso derivatives: nitroso derivative of acetone-diphenylamine. (5) Formic acid derivatives: formic acid derivative of acetone-diphenylamine. (6) Naphthol addition products: the b -naphthol addition product of acetone-aniline, acetone p.p1-diaminodiphenylmethane, chloracetone-aniline, and acetone-diphenylamine. Instead of b -naphthol there may be used a -naphthol, methylene-di-b -naphthol, dihydroxynaphthalenes such as 1.5 dihydroxynaphthalene. p.p1-Di-(naphthylamino)-diphenylmethane is prepared by heating a mixture of p.p-diaminodiphenylmethane (1 mol.) and b -naphthol (2 mols.) in presence of calcium chloride or iodine. p.p1-Di-(naphthylamino)-diphenyldimethylmethane is prepared similarly to the foregoing compound.ALSO:Rubber is treated to retard deterioration, with the reaction product of a ketone and an aromatic amino compound, or with a derivative of such a reaction product. Thus aldehyde derivatives, sulphur derivatives such as of acetone diphenylamine, formed by the action of sulphur, carbon disulphide, sodium polysulphides or sulphur chlorides on the reaction product, nitroso derivatives as of acetonediphenylamine, formic acid derivatives as of acetonediphenylamine, or naphthol addition products may be used. Thioketones or the corresponding ketone dihalide may be used instead of the ketone to form the initial reaction product. The reaction product may be formed with or without the aid of a dehydrating agent such as calcium chloride, iodine, sulphanilic acid, phosphorus pentoxide, sodium hydroxide, magnesium perchlorate, acetic acid, barium oxide, zinc chloride, sulphuric acid, &c. Alternatively the zinc chloride double salt of the amine may be used. Numerous examples of the preparation of these reaction products are given.