2567. Phosphate of Lime as a Mordant

2567.    Phosphate of Lime as a Mordant. A rather thick syrupy solution of phosphate of lime (bone-ash) in hydrochloric acid having been recently recommended as a mordant to be used after a previous sumaching of the goods, Dr. Reimann states that, according to his researches, the phosphate of lime solution is altogether superfluous for aniline dyes, since a sumaching with 4 pounds sumach to 20 pounds cotton is of itself a sufficient mordanting to fix aniline colors excellently. The application of the phosphate of lime solution as a mordant for cochineal colors upon cotton ho also considers as quite useless.

2568. New Mordant Applicable to Aniline Colors

2568.     New Mordant Applicable to Aniline Colors. For this purpose the oxide of zinc, in accordance with a patent taken out in France by MM. Biot and Thisau, may be used for mordanting aniline blue upon cotton, or the iodine green upon wool. The mordanting is effected by simply immersing the goods for some hours in a bath of cold water, in which chloride or acetate of zinc has been dissolved until the solution shows 2° Baum'e; for the wool the mordanting bath should be at a boiling heat, and the goods should also be placed in a warm bath of tannin 90° Fahr. for half an hour. In dyeing, a hot solution of the color must be used, to which should be added, in the case of the cotton, some chloride of zinc, and, in the case of the wool, a certain amount of tannin solution.

2569. To Dye Aniline Opal Blue on Cotton

2569.    To Dye Aniline Opal Blue on Cotton. To mordant the aniline color known as opal blue upon cotton it is recommended to rinse the goods, after bleaching, in a dilute solution of soda crystals, to neutralize the acid of bleaching, then to pass them into a hot bath of soap, in which oil exists in emulsion in these proportions: Water, 100 liters (211 pints); soap, 8 kilos (214 pounds troy); oil, 2 kilos (51/8 pounds troy). "Wring them out, dry, and pass them into a solution of acetate of alumina of about 4° or 5° Baum'e, wring out, dry, and rinse in hot water. Finally dye in a solution of opal blue to which acetic acid has been added. The temperature of the dye bath should be 75° to 90° Fahr. Rinse and dry.

2570. Difficulty in Dyeing Cotton with Aniline

2570.  Difficulty in Dyeing Cotton with Aniline. This difficulty consists in the irregularity of intensity of color when the aniline colors are applied. This effect is attributed to the unequal oxidation of the tin salts applied before dipping the goods into the dye bath; in using these colors, avoid the use of the tin salts, which have little or no beneficial effect on the results in any case; and dip the goods into the dye bath, after treating with infusion of nut-galls or sumach. If tin must be used, the best salt of that metal is the bichloride.

2571. Aniline Black

2571.    Aniline Black. "When a salt of aniline in solution is exposed to the action of certain oxydizers, as salts of copper, chlorate, and bichromate of potassa, it yields a black dye, of such depth that ordinary gall or madder blacks appear gray or green in comparison. The fastness of this color, its resistance to the action of acids, alkalies, soaps, and sunlight, render it of great importance to manufacturers, and make it one of the great achievements of late years.