DE302792C - - Google Patents

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JVe 302792 CLASS 22 d. GROUP

FARBENFABRIKEN vorm. FRIE_DR. BAYER & CO.

in LEVERKUSEN b. CÖLN a. Rh. Process for the preparation of yellow sulfur dyes.

Addition to patent 292148 *).

Patented in the German Empire on August 22, 1916. Longest duration: December 10, 1929.

By fusing m- and o-toluidine with benzidine and sulfur at higher temperatures, only dull and worthless sulfur dyes can be obtained.
The remarkable observation has now been made that the primulin-like intermediates which are obtainable from a molecule of a tolidine and a molecule of o- or p-toluidine, when fused with benzidine and sulfur, give valuable clear greenish yellow sulfur dyes with good fastness properties, which are known before the products of the main patent 292148 obtainable at higher temperatures by fusing primary diamines of the diphenyl series methylated in the core or their halogen substitution products, with or without the addition of benzidine, with more than one molecule of sulfur, are characterized by greater abundance.

Example 1.

15.5 parts of p-toluidine, 15.5 parts of o-tolidine and 18.5 parts of sulfur are heated to 180 to 210 "for 15 to 20 hours until the evolution of hydrogen sulfide has subsided.

The ground melt is insoluble in most organic solvents. from This body is absorbed with a yellow-brown color by hot nitrobenzene, as well as by Sulfuric acid monohydrate or fuming sulfuric acid, but it lets itself through Do not convert high-percentage oleum into a sulfonic acid like dehydrothiotoluidine and the primulin. It does not dissolve in alkaline sulfur, so it is not yet a sulfur dye represent.

To convert into such, the entire finely ground melt is heated with 27 parts of benzidine and 80 parts of sulfur at 180 °, beginning with a gradual increase in temperature to 230 to 250 °, until the evolution of hydrogen sulfide subsides, which is the case after about 15 hours. The melt is dissolved in finely ground state in 300 parts of sodium hydroxide solution or 80 parts of sodium sulphide in concentrated aqueous solution in 3 to 4 hours at 110 to 120 ⁰ like by conventional methods. The dye is a yellow powder, which turns out of the sulfur-sodium bath in very clear yellow tones.

*) Former additional patents 293187 and 293558.

To produce the dye described, it is not absolutely necessary first to show the primulin-like intermediate of p-toluidine and o-tolidine in a special way; one can rather the representation of the intermediate product with that of the sulfur dye effect in one operation.

Example 2.

15.5 parts of p-toluidine, 15.5 parts of o-tolidine, 27 parts of benzidine and 100 parts of sulfur are given in Example 1 (paragraph 2) Way merged and processed. It becomes such a dye from those described above Properties preserved. Instead of p-toluidine one can also use its isomers and instead of o-tolidine other nuclear methy-

• Use lated diamines of the diphenyl series. The dyes show similar tones "and Properties. ■

The specified proportions of the individual components, as well as those in the Amounts of sulfur to be used ■ can be changed within wide limits will.

Claims (1)

Patent claim: Modification of patent 292148 and its additions 293187 and 293558 Protected process for the preparation of yellow sulfur dyes, consisting of that instead of the simple nuclear methylated diamines of the diphenyl series or their derivatives used in the main patent and the earlier additional patents, here either by merging of the diamino compounds mentioned with ο-, m-, or p-toluidine in equimolecular proportions Amounts and sulfur available primulin-like intermediates or directly Mixtures of the nuclear methylated diamines or their derivatives and Toluidines fused with benzidine and sulfur at higher temperatures.