Scientific American 14, 4.4.1863
Preparing Red Colors.
We should judge from the great number of patents which have recently been taken out iu France and England, for applying and preparing coal-tar colors, that these have nearly superseded (in Europe) all the colors which were formerly derived from innumerable dye-woods. The following is the condensed description of a patent, obtained by W. Spence, of London, for obtaining a fast brilliant red by the transformation of carbolic acid. The inventor takes 23 pounds of phenic or carbolic acid, about 15 pounds of oxalic acid and 10 pounds of sulphuric acid, and mixes these together in a vessel heated over a fire. A deep greenish substance of the consistency of pitch is thus produced, which is washed with boiling water to remove the excess of acid in it. It is next thoroughly dried and reduced to powder. About 2½ pounds of this product are now mixed with 5½ pounds of the ammonia of commerce, placed in a close vessel and submitted to a heat of 270° Fah., for three hours, then allowed to cool in the vessel. The coloring matter is now found to be dissolved in the ammonia, forming a thick liquor. When this is treated with sulphuric or hydrochloric acid it forms a deep red precipitate, called peonine, which is capable of dyeing silk, wool, and other textile fabrics a fast red color.
Preparing Blue Colors.
In order to obtain a blue color for dyeing and printing, Mr. Spence mixes five parts, by weight, of the above-described red coloring matter with six parts of aniline, and subjects the mixture to a heat of about 210° Fah., for about three hours, when the red color is gradually transformed into a blue coloring substance, which is washed thoroughly with water, then boiled in water acidulated with sulphuric or hydrochloric acid. After this it is heated with coal oil and again washed with a dilute solution of caustic soda, then mixed with boiling water acidulated with sulphuric acid and dried. It is now obtained in powder of a golden shade; it is soluble in alcohol and methyle, and is suitable for dyeing and printing generally.
Preparing Blue Colors.
W. H. Perkin, of Sudbury, England, has also taken out a patent for printing and dyeing coal-tar colors on cotton and linen fabrics. He takes either aniline purple, violet, blue de Lyon, or magenta, and mixes it with 1,000 parts of the acetate of alumina, having a density of 10 degrees in Beaume's hydrometer, and 80 parts, by weight, of arsenite of soda, and stirs them all together and then adds starch or gum to thicken the solution for printing. It is applied to the cloth by machinery used for printing, after which it is submitted to the action of steam in the usual manner of steaming calicoes. The aniline colors are first dissolved in alcohol, before being mixed with the mineral mordants, at the rate of 16 parts of dry coloring matter to the 1,000 parts of the acetate of alumina. For the magentas color about 136 parts of the arsenite of soda is used, but for the other colors only 90 parts. The application of aniline colors to calicoes is very troublesome. One of our New England calico-printers told us recently that he had found it very difficult to mix such colors for printing on cloth.
Blue Coal tar Color.
A patent has also been taken out by E C. Nicholson, of London, for a soluble aniline blue color, obtained by the mode described as follows:--He takes, by preference, the substance known as "blue de Lyon" or that known as "azaline," these being blue-coloring matters obtained from aniline and similar bases. He extracts all soluble matter from it by boiling it with water containing sulphuric acid. He employs for this purpose the said acid in the proportion of about four ounces, by weight, to every gallon of water. When all or nearly all the soluble matter is extracted, he collects the insoluble matter and dries it thoroughly. He then takes this substance, reduced to powder, and adds to it about four times its weight of concentrated sulphuric acid of commerce, and he raises the temperature of the mixture to about 300, Fah., and keeps it stined until all is dissolved; and he then maintains it at about this temperature until a sample. when added to water, is entirely dissolved. If the temperature is raised too high sulphurous acid is evolved and the dye gradually destroyed. The acid solution c an be diluted and used for dyeing or printing in the ordinary way, or, if too acid, the excess of sulphuric acid may be removed by lime or other suitable alkali; or, if an excess of lime be added, the sulphuric acid is entirely precipitated in the form of sulphate of lime, and a colorless solution is obtained which, when neutralized with any vegetable or other acid, developes the improved soluble blue dye.
Caustic Soap in Cleaning Flax.
A patent has been taken out by Mr. Henry, of London, for the use of a very caustic soap in the treatment of vegetable products, such as hemp, flax, nettles, straw, grass, &c., to obtain fiber for spinning. The soap is made by combining a concentrated solution of caustic alkali, with oil, grease or any saponifiable substance, so as to have an excess of alkali. He states that flax, &c., may be taken without any other preparation after being gathered and steeped in a solution of such soap, when the fiber will be dissentegrated from the glutinous parts of the plants, and pulp for paper also obtained. Such treatment of plants containing fiber, with a small quantity of caustic soap, it is stated, answers the purpose of the usual retting process, and the subsequent crushing operations of the plants are rendered much easier. The soap separates the gummy and oily matter from the fiber, and by subsequent washing it is removed with the water leaving a clean and beautiful fiber.
New Product from Sea-weed.
A new product has been obtained from sea-weeds of the order algæ by T. H. Ghislin, of London. The sea-weed is first steeped in dilute sulphuric acid for about three hours, then thoroughly dried and becomes hard, after which it is ground to an impalpable powder. About 10 per cent of glue dissolved in water, 5 per cent of gutta-percha and 2½ per cent of india-rubber dissolved in naphtha, and 10 per cent of coal tar, are thoroughly mixed and boiled together. To this mix-ture 5 per cent of the flowers of sulphur, 5 per cent of rosin, 2½ per cent of alum and 60 per cent of the pulverized sea-weed are added and intimately mixed in the boiling compound. The mass is now placed in an oven and heated to 300° Fah., when it forms a plastic compound capable of being molded, em-bossed and stamped into various articles useful in the ornamental arts, like gutta percha, as it becomes very hard and durable when cold.
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