USRE11491E - To the farbenfabriken - Google Patents

Description

UNITED STATES PATENT OFFICE.

KARL PATHE AND OSCAR DRESSEL, or ELBERFELD, GERMANY, ASSIGNORS.

To run FARBENFABRIKEN, VORMALS FR. BAYER & 00., or SAME PLACE.

RED DYE. I

SPECIFICATION forming part of Beissued Letters Patent No. 11,491, dated April 30, 1895.

Original No. 532,479. dated January 15 1895. Application for reissue filed March 25, 1895- Serial No. 543,164.

France December 22, 1893, No. 228,125.

. To all whom, it may concern:

,Be it known that we, KARL PATHE and OSCAR DRESSEL, chemists, doctors of philosophy,'and subjects of the Emperor of Germany,

residing at Elberfeld, Prussia, Germany, (assignors to the FARBENFABRIKEN, VORMALS FR. BAYER 8:: (30., of Elberfeld,) have invented certain new and useful Improvements in the Manufacture of Red Azo Dye, (for which the IO aforesaid FARBENFABRIKEN, VORMALS FR. BAYER & .Co., has alreadyobtained Letters Patent. in France, No. 928,125, dated December 22, 1893;) and we do hereby declare the following to be an exact and clear description of our invention.

Our invention relates to the production of red substantive dye-stuffs by combining one .molecular proportion of diazotized dehydrothio-para-toluidin (or the corresponding quan- 2o tity of the diazo compound oiYthe homologous dehydroi hiomeia-xylidin or dehydrothio pseudo-cumidin) with one molecular proportion of amidonaphtholdisulfo acid.

The aforesaid aniidonaphtholdisulfo acid is, for, example, obtained in the following manner: parts, by weight, of beta naphthyl'amin sulfo acid (NII :SO l-I:-'2:5) are gradually stirred into ninety parts, by weight, of fuming sulfuric acid containing forty per cent. of sulfuric anhydride and the mix-. ture is heated at about 100 centigrade,while' small tests from time to timeare taken out from the sulfonation mixture and diazotized in a suitable manner. Heating is continued until such diazo compouud when combined in an alkaline solution with the so-called R salt, yields .a e-stuit' soluble with great 40 readiness in water. At this'stage the whole sulfuric mixture is poured into ice-water and the resulting liquid is neutralized with limewater. After filtering off the calcium sulfate a filtrate is obtained which contains the.

calcium salt of the so formed naphthylamintrisulfo acid This calcium salt is transformed in the well known manner into the potassium salt and Patented in the resulting, solution of the potassium salt is evaporated until the addition of hydrochloric acid to a test portion effects the separation of the acid potassium salt of the above naphthylamiu trisulto acid in crystals. Then this stage is arrived at the whole evaporated solution is acid ulated by means of hydrochloric acid (21 Bauin) and cooled down, and tinallythe crystalline precipitate is filtered off, pressed and dried; The thus obtained acid 50 potassium salt of the naphthylamin trisulfo acidis melted with alkalies,'for instance, as follows: Thirty-six parts, byweight, of the acid potassium salt of the above naphthylamin trisuli'o acid are heated with sixty-nine parts, by weight, of caustic potassa and thirty-four parts, by weight, of water, in a closed vessel capable 'of withstanding pressure and provided with stirring apparatus, at about 180 centigrade. This operation is prolonged until a test portion taken out from the melted mass and combined with a suitable diazo compound no longer shows any increase of the sotormed dye-stuff. Ihis will be after from about eight to ten hours. The melted mass is then diluted with a'small quantity of water and acidulated with'hydrochloric acid. The acid potassium salt of the new amido-naphtholdisulto acid then separates as a crystalline mass which is filtered off, pressed and dried. In order topurify, this acid salt is redissolved in hot water and precipitatedby means of potassium chlorid. Thus it forms white needles. The solution of this acid potassium salt'in Water 0 shows a violet-blue fluorescence, which turns into green on adding alkali.

In carryingoutthe preparation of the aforesaid dye-stuifs we can, for example, proceed as follows: Twenty-four parts, by weight, of 95. dehydro-thiotolnidin are mixed in a very fine condition with water and forty parts, by Weight, of hydrochloric acid (containing thirty-three per cent. of pure hydrochloric acid are added to the above mixture which is well too i ate or dilute soda-lye. 5

-- cooled. 0n adding seven parts, byweighhof gradually into a solution prepared by dissolvmg 35.7 parts, by weight, of the acid potassium salt of the above described -am-idonaphtholdisnlfo acid in water with the addition of one hundred and ten parts, by weight, of sodium carbonate. After about twelve hours themixture is heated at about centigrade and mixed with a suitable quantity of common salt, in order to separate the dye-stud. If necessary, the dye may be purified once more by redissolving the samein water and salting out. After filtering ompre'ssing anddrying, the dye-stulflforms a brown powder easily sol nble in water with red color, almost insoluble in alcohol and concentrated sodalye. The color of thewatery solution of the dyestuff is not altered by the addition of dilute ammonia liquor, a solution ofsodium carbon- By concentrated sulfuric acid (66 Baume') the dye-stud is dissolved with a bluish-red color.- On adding icewater to this sulfuric acid solution reddishbrown flakes are precipitated, which represent the free sulfo acid of the dye-stuff.

The dye produces on unmordanted cotton clear red shades fast to the action of alkali and acid. When fixed on the fiber it can be rediazotized and coupled with so-called developers, as, for example, beta naphthol, new shades of great fastness to soaping and milling being produced in this manner.

Analogous orsi milar dye-studs a re obtained if in the last described processthe dehydrothio para toluidin is replaced by thecorrcspending quantity of the homologous dehydrothio-meta xylidin or dehydrothio-pseudo cumidin.

Tlheprocess of producing dyes can also be carried out in an acid solution instead of using an alkaline solution as hereinbefore described.

Of course, the well known sulfo derivatives of the above named thio bases can also be em ployedin the above process, dye-stuffs be ing thus produced which in general show the same properties asthose derived from the aforesaid thio bases; butowing to the greater cheapness of such .thio bases, compared with that of the sulfo derivatives thereof, we prefer to use the thio bases'instead of the sulfo derivatives thereof for the production of the dyes hereinbefore defined.

When, in the claims, of this specification, we refer-to diazotized dehydrothio-para-toluidin base, we mean to include as equivalents thereof the corresponding quantity of the d-iazo compound of the homologous dehydrothio-meta-xylidin, or dehydrothio pseudo-ctr molecular proportion of the hereinbeforo described amidonaphtholdisulfo acid (nn,=on;so,n=so,n=2can in an alkaline or acid solution.

2. As a new article of manufacture, the dye which is producible from one molecnlarproportion of diazotized dehydrothio-para-toluidin, having the formula:

' SO Na forming a brown powder, easily soluble in water with a red color, almost insoluble in concentrated soda-lye and alcohol, being d is solved by concentrated sulfuric acid with a bluish-red color, reddish-brown flakes being separated on the addition of icewvater to the above sulfuric acid solution, producing on nnmortlauted cottonclear red shades of great fastness to the action of alkali and acid being rediazotizable when fixed on the fiber and producing new shades of great fastness to soaping and milling when, after previous diazotization on the fiber, being coupled with any dye-stuff component for developers, as, for instance, beta naphthol.

In testimony whereof we have signed our names in the presence of two subscribing witnesses.

KARL PATHE. OSCAR DRESSEL.

.Witnesses:

T. H. STRAUSS, A. STRAUSS.