ALIZARIN, ARTIFICIAL

C 14 H 8 O 4 . This colour was first obtained by Graebe and Liebermann in 1869 from a nth rach in on, an oxidation product of anthracen, this latter being a substance which is formed during the destructive distillation of coal-tar. These chemists converted anthracen into an tich in on by means of nitric acid. The crude anthracen is previously purified by treatment with benzoline (petroleum spirit), aided by heat, and by being subjected to the action of the centrifugal machine to fusion, and to sublimation. According to the original method of preparing alizarin, the a nth rach in on was first converted into a dibromide of a nth rach in on by treatment with bromine, and this bromated compound, by further treatment either with caustic potash or soda at a temperature of 180° to 200° C., converted into alizarin-pota ium (or alizarin-sodium if caustic soda has been used), from which the alizarin is set free by means of hydrochloric acid. Alizarin is now procured from a nth rach in on by treatment at a temperature of 260° C., with concentrated sulphuric acid of 1·84 sp. gr., the a nth rach in on being converted into a sulpho-acid; this acid is next neutralised with carbonate of lime, the fluid decanted from the deposited sulphate of lime, and carbonate of potash added to it, with the object of throwing down all the lime. The clear liquid is then evaporated to dryne , the resulting saline ma is converted into alizarin-pota ium by heating it with caustic potash. From the alizarin-pota ium thus obtained the alizarin is set free by the aid of hydrochloric acid. In another method the preparation of a nth rach in on is avoided, and anthracen employed directly, by first converting it, by means of sulphuric acid and heat, into anthracen sulphonic-acid. After having been diluted with water, the solution of this acid is treated with oxidising agents (peroxides of manganese, lead, chromic acid, nitric acid), and the acid fluid is afterwards neutralised with carbonate of lime. When peroxide of manganese has been used, the manganese is also precipitated as oxide. The oxidised sulpho-acid having been previously converted into a pota ium salt, the latter being heated with caustic potash, alizarin is obtained. The details of these two proce es will be found set forth in the terms of the patent taken out by Me rs Caro, Graebe and Liebermann, further on. The following method of preparing alizarin from anthracene para naphthalene and their homologues is by Girard. The material used is that which distils between 290° and 360°; it is purified by distillation and pre ure, the portion which pa es over, between 300° and 305°, being collected separately. This mixture is treated with pota ium chlorate and hydrochloric acid, whereby it is converted into tetra-chlorinated products. These are oxidised either by nitric acid in the water bath, or by a metallic oxide (red or brown oxide of lead), and sulphuric or acetic acid. In the first place a mixture of dichloranthraquinine and chloride of chloroxyanthranyl are obtained. These substances are treated in presence of a metallic oxide (oxide of zinc, oxide of copper, or litharge), with an alcoholic solution of sodium acetate. The metallic oxide removes the last atom of chlorine from the sodium chloroxyanthranilate, and converts it, like the dichloranthraquinine, into alizarin. The purification is effected by means of benzine, petroleum, ., which di olve out the foreign matters, and by succe ive precipitation from the alkaline solutions by mineral acids. The foreign matters may also be separated by means of a little alum, when it is nece ary to work with neutral potash or soda salts. Another method for the preparation of alizarin has been patented by Dale and Schorl emmer. It is as follows: 1 part of anthracen is boiled with 4 to 10 parts of strong sulphuric acid, then diluted with water, and the solution neutralised with carbonate of calcium, barium, pota ium, or sodium. The resulting sulphates having been removed by nitration or crystallisation, the solution is heated to between 180° and 260° with caustic potash or soda, to which a quantity of pota ium nitrate or chlorate has been added, about equal in weight to the anthracen, as long as a blue-violet colour is thereby produced. From this product the alizarin is separated in the usual way by precipitation with an acid. Several other patents have been taken out for the preparation of artificial alizarin. The specification of Me rs Caro, Graebe, and Liebermann, and dated June 25th, 1869, was the first which was taken out in England. We quote it here because it enters more fully into detail than any of the others. “Our invention is carried into effect by means of either of the two proce es which we will proceed to describe. “In the one proce we proceed as follows—We take about one part by weight of anthraquinone and about three parts by weight of sulphuric acid of about specific gravity of 1·488, and introduce the same into a retort, which may be made of gla , or porcelain, or of any other material not easily acted upon by sulphuric acid, and the contents are then to be heated up to about 260° Centigrade, and the temperature is maintained until the mixture is found no longer to contain any appreciable quantity of unaltered anthraquinone. The completion of this operation may be ascertained or tested by withdrawing a small portion of the product from time to time, and continuing the operation at the high temperature until such product upon being diluted with water is found to form a substantially perfect solution, thereby indicating that the anthraquinone has become either entirely or in greater part converted into the desired product. The products thus obtained are then allowed to cool, and are diluted with water; carbonate of lime is then added in order to neutralise and remove the exce of sulphuric acid contained in the solution; the mixture is then filtered, and to the filtrate carbonate of potash, or carbonate of soda, by preference in solution, is to be added until carbonate of lime is no longer precipitated; the mixture is then filtered, and the clear solution is evaporated to dryne , by which means the potash or soda salts of the sulpho-acids of anthraquinone are obtained, and which are to be treated in the following manner:—We take about one part by weight of this product, and from two to three parts by weight of solid caustic, soda, or potash; water may be added or not, but by preference we add as much water as is nece ary to di olve the alkali after admixture; we heat the whole in a suitable ve el, and the heating operation is continued at a temperature of from about 180° to 260° Centigrade, for about one hour, or until a portion of the mixture is found upon withdrawing and testing it to give a solution in water, which being acidulated with an acid, for example, sulphuric acid, will give a copious precipitate of the colouring matters. The heating operation having been found to have been continued for a sufficient time, the resulting products are then di olved in water, and we either filter or decant the solution of the same, from which we precipitate the colouring matters or artificial alizarin, by means of a mineral or organic acid, such, for example, as sulphuric or acetic acid. The precipitated colouring matters thus obtained are collected in a filter or otherwise, and after having been washed may be employed for the purpose of dyeing and printing, either in the same way as preparations of madder are now used or otherwise. “In carrying out our other proce we proceed as follows:—We take about one part by weight of anthracene and about four parts by weight of sulphuric acid of specific gravity of about 1·848, and the mixture being contained in a suitable ve el, is heated to a temperature of about 100° Centigrade, and which temperature is to be maintained for the space of about three hours; the temperature is then to be raised to about 150° Centigrade, which temperature is to be maintained for about one hour, or until a small portion of the product when submitted to the two subsequent proce es hereinafter described is found to produce the desired colouring matters; we then allow the result obtained by this operation to cool, and dilute it with water, by preference in the proportion of about three times its weight. To the solution thus obtained we add for every part of anthracene by weight which had been employed in the previous operations, from about two to three parts by weight of peroxide of manganese, preferring to employ an exce , and we boil the whole strongly for some time, and in order fully to ensure the desired degree of oxidation the mixture may be subsequently concentrated, and by preference be evaporated to dryne , and the heat be continued until a small portion of the oxidised product, when submitted to the subsequent proce es hereinafter described will produce the desired colouring matters. We then neutralise and remove the sulphuric acid contained in this mixture, and at the same time precipitate any oxides of manganese that may be held in solution, by adding an exce of caustic lime, which we use by preference in the form of milk of lime, and we add the same until the mixture has an alkaline reaction. We then filter, and add to the filtrate carbonate of potash or soda, until there is no further precipitation of carbonate of lime. The solution is then filtered and evaporated to dryne , and we thus obtain the potash or soda salts of what we call the sulpho-acids of anthraquinone. “In effecting the conversion of the oxidised products thus obtained into colouring matters, or into what we call artificial alizarin, we proceed as follows:—We take one part by weight of this product, and from two to three parts by weight of solid caustic soda or potash, and water may be added or not, but by preference we add as much water as may be nece ary to di olve the alkali. After admixture we heat the whole in a suitable ve el, and continue the heating operation at a temperature of about 180° to about 260° Centigrade for about one hour, or until a portion of the mixture is found to give a solution in water, which upon acidulation with an acid, for example, sulphuric acid, is found to give a copious precipitate of the colouring matters. The heating operation having been found to have been continued for a sufficient time, we then di olve the product in water, and either filter or decant the solution of the same, from which we precipitate the colouring matters or artificial alizarin by means of a mineral or organic acid, such, for example, as sulphuric or acetic acid. The precipitated colouring matters thus obtained are collected on a filter or otherwise, and after having been washed may be employed for the purpose of dyeing and printing, either in the same way as preparations of madder are now used or otherwise. “Instead of acting upon anthracen by means of sulphuric acid of the density before mentioned, fuming sulphuric acid may be employed, but we prefer to use the ordinary kind before described. “In order to effect the proce of oxidation, before referred to, other oxidising agents may be used in the place of the oxide of manganese, before mentioned, such, for example, as per i oxide of lead, or chromic, nitric, or other acids capable of effecting the desired oxidation may be employed.” Mr W. H. Perkin’s patent is similar in principle to that of Me rs Caro, Graebe, and Liebermann, and is dated only one day later. The following is an outline of a patent taken out in France in May, 1869, by MM. Brœnner and Gutzkon, for the manufacture of artificial alizarin. One part of anthracen is heated with two parts of nitric acid, sp. gr. 1·3 to 1·5. The anthraquinone thus produced is washed and di olved at a moderate heat in sulphuric acid. Mercuric nitrate is now added, which converts the anthraquinone into alizarin, The ma thus formed is di olved in an exce of alkali, which precipitates the oxide of mercury, and retains the colouring matters in solution. The alkaline liquor is decanted and neutralised with sulphuric acid, and the precipitate thus formed is washed and collected. If not quite pure the treatment with alkali must be repeated. (The complete specification of this patent is published in the ‘Moniteur Scient i fique,’ vol. xi, p. 865.) In England a large quantity of artificial alizarin is manufactured by the proce of Mr Perkin, and is used as a substitute for madder and madder extract, in Turkey red dyeing and topical styles. The largest makers of artificial alizarin on the continent are Me rs Ge ert Frères, of Ebelfort, Me rs Maister, Lucius and Co., of Hæchst, near Frankfort, and the Badische Anilin und Soda Fabric, Mannheim. The following recipes for printing with artificial alizarin are extracted from Mr Crookes’ ‘Practical Handbook of Dyeing and Calico Printing’: Reds. 5 lbs. alizarin paste (10 per cent.); 16 lbs. thickening; 1 lb. acetate of alumina, at 15° Tw.; 1 ⁄ 2 lb. acetate of lime, at 25° Tw. Pinks. The above diluted with 2 or 3 parts of thickening. For double printing, when deep red is printed on first, the goods must be steamed one hour before the second printing takes place. After the second printing the goods are again steamed for one hour, and aged for twenty-four hours; they are then pa ed through one of the following baths, at from 120 to 140 F., remaining in the bath not longer than 1 to 1 1 ⁄ 2 minute:— 250 gals. water; 60 lbs. chalk; 3 lbs. tin crystals. Or, 250 gals. water; 40 lbs. chalk; 10 lbs. arseniate of soda. The goods are then washed, and cleaned as follows:— Take, for 10 pieces of fifty yards each,— 1st. Soaping at 120° F., 3 lbs. soap; 1 ⁄ 4 lb. tin crystals. 2nd. Soaping at 160° F., 3 lbs. soap; 3rd. Soaping at 175° F., 3 lbs. soap. Wash between each soaping. Red for Mosaics. 8 lbs. alizarin paste (10 per cent.); 10 quarts thickening; 9 1 ⁄ 2 oz. nitrate of alumina, at 23° Tw.; 19 oz. acetate of alumina, at 15° Tw.; 13 oz. acetate of lime, at 25° Tw. Or, 10 lbs. alizarin paste (10 per cent.); 10 quarts thickening; 13 oz. nitrate of alumina, at 23° Tw.; 19 oz. acetate of alumina, at 15° Tw.; 16 oz. acetate of lime, at 25° Tw. Another Red without Oil . 8 1 ⁄ 2 lbs. alizarin paste (10 per cent.); 9 1 ⁄ 2 lbs. acetic acid, at 12° Tw.; 3 1 ⁄ 2 lbs. wheat flour; 5 pints water. Boil well and stir till cold; then add— 1 lb. acetate of lime, at 29° Tw.; 2 lbs. nitrate of alumina, at 23° Tw.; 3 lbs. hyposulphite of lime, at 13° Tw. Purple. 3 lbs. alizarin paste (10 per cent.); 10 quarts purple thickening; 6 oz. pyro lignite of lime, at 18° Tw.; 12 oz. acetate of lime, at 25° Tw. The printed goods are steamed for an hour or two, and then aged from twenty-four to thirty-six hours. They are then padded in the chalk and arseniate of soda bath; after which they are washed and soaped in a single soap-bath without tin crystals; and, if needful, cleaned in a weak solution of bleaching powder. Thickening for Reds. 12 lbs. wheat starch; 40 quarts water; 4 quarts acetic acid, 9 9 Tw.; 1 1 ⁄ 4 lbs. gum tragacanth; 2 lbs. olive oil. Boil well together, and stir till cold. Thickening for Purple. 10 lbs. starch; 27 quarts water; 3 quarts acetic acid; 1 1 ⁄ 8 lbs. gum tragacanth; 2 lbs. olive oil. Boil well together, and stir till cold. The mordants in the above recipes are prepared as fellows: Acetate of Alumina. Stir 30 lbs. of hydrate of alumina into six quarts of acetic acid, warm, filter, and reduce to the specific gravity required. The hydrate of alumina is prepared by di olving 72 lbs. of alum in 100 gals. of water, and 62 lbs. soda in 100 gals. of water. The two solutions are mixed, this precipitate is washed eight times by decantation, collected on a filter and pre ed. It must be di olved on the filter before it gets dry. Nitrate Of Alumina. 2 lbs. nitrate of lead; 2 lbs. alum; 2 quarts water. Di olve and filter off the liquid from the precipitate, and dilute to proper standard. The reds are turned more yellow by nitrate than by acetate of alumina, and when the former is used more acetate of lime is taken in addition. Acetate of Lime. A solution of acetate of lime at 25° Tw. contains 25 per cent. of acetate of lime; generally 1 ⁄ 10 th of the weight of alizarin paste is required; but with a fresh quantity of alizarin it is safer to ascertain, on a small scale, the amount needed. Brown. 13 1 ⁄ 4 lbs. alizarin paste (15 per cent.); 9 quarts thickening; 2 lbs. nitrate of alumina, at 29° Tw.; 15 oz. acetate of alumina, at 19° Tw.; 15 oz. red pru iate potash, di olved in water; 1 lb. 1 oz. acetate of lime, at 29° Tw. To obtain a yellower shade, for every quart of mixed colour, 1 oz. bark liquor, at 30° Tw., may be added. Old spoiled red colours may be advantageously used for browns by adding per quart, 3 ⁄ 4 oz. to 1 oz. red pru iate, di olved in water.