Volume 3

Chemistry, theoretical, practical, and analytical : as applied to the arts and manufacturers / by writers of eminence.

Date:
[1882]
Catalogue details

Licence: Public Domain Mark

Credit: Chemistry, theoretical, practical, and analytical : as applied to the arts and manufacturers / by writers of eminence. Source: Wellcome Collection.

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    7(!0 DYEING AND CALICO P remember the ease with which the metal passes from one degree of oxidation to another; thus from V.>05 the highest degree, to V.,04, and vice versa. In this way it doubtless acts, as >1. Guyard has suggested, as a carrier of the oxygen of the chlorate to the aniline, being alternately reduced and reoxi- dized, so that an infinitely small quantity of vana- dium compound will convert an infinitely large quantity of aniliue salt into aniline black, reminding one of the action of nitrous fumes in the leaden chamber. “Some time after the discovery of aniliue black, Robert Pinkney, of the firm of Blackwood & Co., of London, discovered, independently of Light FOOT, that vanadium can be most advantageously substi- tuted for copper in the formation of aniline black; and he employed this reaction for the preparation of a permanent marking ink termed ‘ Jetoline,’ of which many thousand of bottles have been sold. A few grains of vanadium—say from seven to twelve —are sufficient to produce, together with hydro- chlorate of auiline and chlorate of soda, a gallon of marking ink. “The subject of the use of vanadium as a valuable dyeing agent was next taken up by the Magnesium Metal Company, of Patricroft, near Manchester; and thanks to the unwearied exertions of S. Mellor, this firm have now succeeded not only in securing a very considerable supply of the rare element which occurs in the Keuper sandstone as the new mineral Mottramite, but are now in a position to produce a vanadium black for both calico printing and dyeing which is perfectly permanent. This is the more remarkable, as up to this time no aniline black made with copper has been produced in commerce ■which will withstand the reducing action of sulphur- ous acid. “As the result of a large number of experiments made with various qualities of commercial aniline, and by varying the strengths of solutions, propor- tions of aniline and sodium chlorate employed, and also by altering the temperature and the conditions of ageing, Meli.or has found (1.) that within certain limits the purer the aniline used the deeper and more permanent is the black obtained. (2.) That there is a maximum density of colour, beyond which, if larger proportions of aniline salt and chlorate are used, corresponding advantages of colour are not obtained. This maximum colour is yielded by 16 ozs. to 20 ozs. of hydrochlorate of aniline per gallon of colour. (3.) That for the formation of a perma- nent black, the amount of aniline salt and sodium chlorate used for 1 gallon of colour must bear a definite relation to each other, the weight of sodium chlorate being about one half that of the aniline hydrochlorate used. (4.) That the permanency of the black depends very much upon the care and skill shown in ‘ ageing ’ the cloth. If the cloth is aged in a moist atmosphere a blue-black is developed, which is very fleeting; but if aged in a dry air, and at a high temperature, a permanent black is obtained. It is also interesting to learn that for other colours also, the use of vanadium appears to be of value, as HINTING.—Aniline Blacks. in the production of catechu browns as well as in some of the brighter aniline dyes.” Aniline Black. — The following processes are at present in use. The goods are stretched out tightly, and exposed to the spray of solutions of a salt of aniline and of the bichromate of potash. The spray is applied by means of a horizontal brush, to which a reciprocating motion is given by suitable machinery. The cotton takes at first an intense green, but becomes a full black on washing and passing through a soap beck. A mixture of equal measures of bisulphate and bimuriate of aniline gives the best results, and the bichromate solution should contain 10 per cent, of the solid salt. Aniline Black.—Muller-Pack prepares proto- chloride of iron by dissolving 3 parts of iron in a mixture of 10 parts muriatic acid and 10 of water, and lets the solution down to 17° Tw. In this the yarn is steeped for two hours, and is then aired for twelve hours. Meantime a solution is made of 3 parts aniline in 5 parts muriatic acid and water, and 2-pj parts of chlorate of potash are added, previously dissolved in 30 parts of water. In this mixture the yarn is steeped, and is then heated in a covered vessel gradually to from 30° to 50° C., and is then hung out to the air. It is next taken through a beck of bichromate of potash. If this black is passed through weak sulphuric acid and then through water and weak caustic soda it takes a bluish tone. Aniline Blues.—If about to dye with diphenylamine blue (the sulpho-conjugated salt of the blue being a compound of lime or baryta), work the cotton in solution of tannin at 3 per cent.; pass through the solution of the blue, dye in water, and dry. If alkaline blues are employed, the sulpho-conju- gated salts of which are soda or ammonia compounds, take for 10 kilos, of cotton a solution of tannin con- taining 3 per cent, of the weight of the cotton ; boil for fifteen minutes, wring, and pass into a beck of 1 k kilo, alum, a quarter tartar emetic, three quarters soda crystals, and a quarter tartaric acid. These wares are all dissolved separately, and the solution of the blue is added last. Heat to 65° to 70° C., enter the cotton, and dye, letting the temperature sink by degrees. The beck may be used continuously, adding more mordant as it be- comes spent. It is best to dye first heavy shades in the beck, then mediums, and then light shades. For saffranin and the aniline greens the goods are passed first into a beck of perchloride of tin at 2 B., wrung, passed into a tannin beck, wrung again, and entered in the dye beck. Cotton may also be mordanted in a solution of nitrate of urea (2 grms. per litre of water), boiled, wrung, passed into a solution of biphosphate of lime (5 grms. per litre of water), wrung, and entered in the dye beck. From this manner very bright shades may be obtained with almost all the anilines. Guernsey Blue for Yarns (10 lbs.).—Prepare with 2 lbs. sumach, and dye at 32° C. with the solution of 2 lbs. Guernsey' blue ; lift, add 1 lb. alum, give the yarn a few more turns, take out, and dry. Fast A niline Blue for Yarns (5 kilos.).—Steep for