Mercapto derivatives of 1 : 3 : 5-triazine applicable as anti-agers and vulcanization accelerators for rubber are obtained by reaction of compounds of the type <FORM:0363690/IV/1> in which at least one x is a replaceable halogen atom, with sulphur compounds in which the sulphur is contained in a residue capable of conversion by saponification or reduction into the mercapto group, and subjecting the product to such saponification or reduction. Suitable sulphur compounds are thiosulphates, sulphocyanides, xanthates, disulphides, and polysulphides. If the product from the primary reaction still contains replaceable halogen atoms it may be caused to react prior to the saponification or reduction with compounds containing replaceable hydrogen, such as water, ammonia, aliphatic and aromatic amines, alcohols, mercaptans, phenols, and thiophenols. Alternatively mercapto-1 : 3 : 5-triazines containing as nuclear substituent an aromatic residue free from sulphonic or carboxylic groups are obtainable by reaction of monoaryl derivatives of 1 : 3 : 5-triazine containing not more than two replaceable chlorine atoms with soluble hydrosulphides. The products may be purified by separation in the form of their ammonium, alkali metal, or alkaline-earth metal salts which are sparingly soluble or capable of being salted out. The following examples are specified: (1) The condensation product from 1 mol. of cyanuric chloride and 1 mol. of aniline is warmed with a concentrated solution of sodium hydrosulphide (4 mols.); the sparingly soluble sodium salt separates on cooling, and is converted into the free dimercaptoanilino-1 : 3 : 5-triazine by means of acetic acid; mercaptoaminoanilino-1 : 3 : 5-triazine is similarly obtained from the condensation product from 1 mol. of cyanuric chloride, 1 mol. of ammonia, and 1 mol. of aniline. (2) The condensation product from 1 mol. of cyanuric chloride and 1 mol. of a -naphthylamine, is heated with a concentrated solution of sodium hydrosulphide (4 mols.) and the dimercapto-a -naphthylamino - 1 : 3 : 5-triazine is precipitated with acetic acid; mercaptoamino-a -naphthylamino-1 : 3 : 5-triazine is similarly obtainable from the condensation product from 1 mol. of cyanuric chloride, 1 mol. of ammonia, and 1 mol. of a -naphthylamine. (3) Dichloroamino-1 : 3 : 5-triazine is heated with a concentrated solution of sodium hydrosulphide; the sodium salt which separates on cooling is converted into the free dimercaptoamino-1 : 3 : 5-triazine by means of acetic acid; the mercaptodiamino-1 : 3 : 5-triazine may be obtained similarly from the chlorodiamino-1 : 3 : 5-triazine. (4) The condensation product from 1 mol. of cyanuric chloride and 2 mols. of aniline is heated with a solution of sodium disulphide (2 mols.) and further heated with addition of sodium sulphide (2 mols.); the precipitate which separates on cooling is recrystallized from hot caustic soda solution and converted into the free mercaptodianilino-1 : 3 : 5-triazine by means of acetic acid. (5) The condensation product from 1 mol. of cyanuric chloride, 1 mol. of aniline, and 1 mol. of ammonia is heated with a solution of sodium disulphide; the precipitate obtained on cooling, with addition of potassium carbonate, is suspended in caustic soda solution at 60 DEG C. and reduced by addition of zine dust; the solution is then filtered hot and the mercaptoaminoanilino-1 : 3 : 5-triazine is precipitated from the filtrate by addition of acetic acid. (6) The condensation product from 1 mol. of cyanuric chloride, 1 mol. of aniline, and 1 mol. of ammonia is introduced into an ice-cooled solution of sodium disulphide, the precipitate is filtered off and dissolved in warm water and the sodium salt salted out from the solution is decomposed with dilute acetic acid. (7) 3 Mols. of sodium thiosulphate are introduced into an ice-cooled aqueous suspension of 1 mol. of cyanuric chloride; on adding acetic acid and boiling the trimercapto-1 : 3 : 5-triazine separates. (8) 1 Mol. of sodium thiosulphate is condensed with 1 mol. of cyanuric chloride in cold aqueous solution, and 2 mols, of aniline in acetic acid solution are added while keeping the solution neutral by addition of sodium carbonate throughout the reaction; on adding acetic acid and boiling the mercaptodianilino-1 : 3 : 5-triazine separates; mercaptoaminoanilino-1 : 3 : 5-triazine is similarly obtained if 1 mol. of aniline is replaced by 1 mol. of ammonia. (9) An aqueous suspension of the condensation product from 1 mol. of cyanuric chloride, 1 mol. of aniline, and 1 mol. of ammonia is warmed with potassium xanthate, the product is boiled with caustic soda solution, and the mercaptoamino-anilino-1 : 3 : 5-triazine is precipitated from the solution obtained. (10) An aqueous solution of potassium sulphocyanide (1 mol.) is added to an ice-cooled solution of cyanuric chloride (1 mol.) in acetone and subsequently aniline (2 mols.) is added at 25-40 DEG C. and the mixture poured into water; the condensation product is filtered off and boiled with sodium sulphide or hydrosulphide to form the mercaptan. (11) A mixture of raw rubber, zinc oxide, sulphur, diphenylguanidine, purified kaolin, and the mercaptan obtained according to (4) above vulcanized in the usual manner has better ageing properties than those of a vulcanized similar mixture from which the mercaptan is omitted. Specification 318,275, [Class 2 (iii), Dyes &c.], is referred to.ALSO:Mercapto derivatives of 1 : 3 : 5-triazine applicable as anti-agers and vulcanization accelerators for rubber are obtained by reaction of compounds of the type <FORM:0363690/V/1> in which at least one #c is a replaceable halogen atom, with sulphur compounds in which the sulphur is contained in a residue capable of conversion by saponification or reduction into the mercapto group, and subjecting the product to such saponification or reduction. Suitable sulphur compounds are thiosulphates, sulphocyanides, xanthates, disulphides and polysulphides. If the product from the primary action still contains replaceable halogen atoms it may be caused to react prior to the saponification or reduction with compounds containing replaceable hydrogen, such as water, ammonia, aliphatic and aromatic amines, alcohols, mercaptans, phenols, and thiophenols. Alternatively mercapto,1 : 3 : 5-triazines containing as nuclear substituent an aromatic residue free from sulphonic or carboxylic groups are obtainable by reaction of monoaryl derivatives of 1 : 3 : 5-triazine containing not more than two replaceable chlorine atoms with soluble hydrosulphides. The products may be purified by separation in the form of their ammonium, alkali metal, or alkaline earth salts which are sparingly soluble or capable of being salted out. The products specified in the examples are the dimercaptoanilino-, mercaptoaminoanilino-, dimercapto-a -naphthylamino-, mercaptoamino-a -naphthylamino-, dimercaptoamino-, mercaptodiamino-, mercaptodianilino-, and trimercapto-1 : 3 : 5-triazines, and as an example of their use a mixture of raw rubber, zinc oxide, sulphur, diphenylguanidine, purified kaolin, and mercaptodianilino-1 : 3 : 5-triazine vulcanized in the usual manner has better ageing properties than those of a vulcanized similar mixture from which the mercaptan is omitted. Specification 318,275, [Class 70, India-rubber &c.], is referred to.