New Colouring Matters.

Textile Mercury, 27.4.1889

The discovery and introduction of new coal tar colouring matters shows no signs of abatement, as colour makers and colour chemists continue fully engaged in the research for new colours. It will be of interest to note the advance that has been made in what is demanded from a coal tar colour to-day, compared to what was required in the early days of the industry. Then, brilliancy was most sought after; to-day, it is fastness. A new colour, to command a sale, must be fast in every respect. Great brilliancy is not so much insisted upon as fastness.

The group of direct cotton colours has been enriched by the addition of five new products. The first of these is

Benzoazurine 3G, A blue dye made by Messrs. F. Bayer and Co. This dyes a brighter blue than the well known benzoazurine R. It is comparatively strong; 2 per cent. will impart a deep tint to unmordanted cotton when dyed in a boiling bath containing 10 per cent. of salt or Glauber's salt, and the bath is more completely exhausted than is the case with the other benzidine blues. We find the blue to resist soaping and dilute acids and alkalis. Strong nitric turns it a bright red, while caustic soda changes it to a bright purple. The original colour is in each case restored by treatment with alkali or acid as the case requires. So far as regards fastness to light and air, it is quite equal to the other benzoazurines in this respect.

Erika is a new pink dye belonging to this class of colours sent out by the Actien-Gessellechaft für Anilin Fabrikation of Berlin. It is dyed with salt or sulphate of soda, and 3 per cent. gives a pale bluish red shade of pink, much resembling that obtained from a blue shade safranine. The colour is thoroughly fast to soaping, and dilute acids; and in this respect it differs from all other reds of this group of colours, and so far as our experiments go it is fairly fast to light. Strong hydrochloric said slightly reddens it, while nitric acid decolounzes it, and caustic soda darkens it slightly. This colour should meet with a large sale.

Hessian Brilliant Purple is made by Messrs. A. Leonhardt and Co., of Muhlheim. It dyes a fiery red on unmordanted cotton from a strong salt bath, and gives a shade more nearly resembling Turkey Red than the other Hessian Purples sent out by the same firm. It is faster to dilute acids than other direct reds and is by them turned a brownish purple. The original colour is restored on washing or by alkalies, strong nitric acid turns it greenish. It is only moderately fast when exposed to light and air, being about equal to benzopurpurine in this respect.

Mikado Orange 4R is a new shade of the Mikado Orange somewhat redder than those hitherto sent out by the makers.

Mikado Brown M is a new shade of the Mikado Browns, and dyes a better brown than the coal tar browns hitherto sent out, and by dyeing in two baths, first with the colour, tannic acid, and salt, and then in a cold bath of copperas, a very dark shade of brown is obtained which resists soaping.

Messrs. Read, Holliday and Sons, of Huddersfield, have placed on the market a new Wool Scarlet in four shades 0, 00, 000, 0000, ranging from a yellow to red shade of scarlet. These are produced from a napthylaninal sulphoacid, the preparation of which is the subject of a patent taken out by Messrs. Holliday. These scarlets are very strong, 2 per cent giving full shades on wool, which are very bright and pure. These scarlets are the brightest we have seen. They are fast to dilute acids and resist soaping, and so far as it has been possible for us to test them at this time of the year, fast to light and air. These new scarlets are worth the attention of woollen dyers. The same firm also send out a new Crystal Blue for wool in two shades R and B, which yield very bright and pure shades of blue using half per cent. of dye-stuff, they are very strong colours, and easily soluble in water. The colour resists washing and strong soaping dilute acids and alkalies, and is faster to light than the general make of blues.

Azo-Carmine is a new dye recently put on the market by the Badische Anilin and Soda Fabrik. It is sold in the form of a paste of a red colour and having a peculiar brilliant golden fluorescence. On standing the colour settles out. Although the colouring matter is insoluble in cold water, it dissolves freely in boiling water, forming a red solution from which, on cooling, the colouring matter again separates. Strong sulphuric acid changes the colour to green, but on diluting with water the original colour is restored. The other mineral acids and alkalies are without action. It is a very strong colour; 3 per cent. is sufficient to give a deep safranine shade to wool, and 5 per cent. a full crimson. It is dyed as usual with Glauber's salts and sulphuric acid. The colour is perfectly fast to acids, alkalies, and washing, and hence should be found useful to the woollen dyer. It can be combined with indigo extract to form very useful compound shades. Thus a good black can be got by using 4 per cent. indigo carmine D, 3 per cent. azocarmine, per cent. orange N. A fawn can be got with 0.2 per cent. azocarmine, 0.1 per cent. fast yellow, and 0.1 per cent. indigo carmine; a drab with 0.2 per cent. of each of the colours used in the last, while using 2 per cent. chrinoline yellow, 0.02 per cent. light green S yellow shade and 0.2 per cent. azocarmine will give a pea green; and sage green can be got with 1 per cent. each of azocarmine, fast yellow, and indigo carmine.

Jet Black is the name given to a new colouring matter for wool, made in two shades R and G. It is dyed in a neutral bath containing salt or Glauber's salts and 5 per cent. gives a deep jet black which is quite fast to soaping, acids, and alkalies, and is said to be fast to light and air. It is made by the Farbenfabriken voni Fr. Bayer and Co., of Elberfeld.

Carnotine is the name which the Clayton Aniline Co., of Clayton, near Manchester, have given to a yellow colouring matter which they have just brought out.
The Clayton Aniline Co. have hitherto mostly confined their operations to the production of the raw materials such as benzol, aniline, nitro benzol, used iu the manufacture of coal tar colours, but recently they decided to extend works orks in the direction of manufacturing coal tar colours. With this object in view they have practically built a new works solely for the production of colouring matters, and carnotine is the first they have, ander the new regime placed on the market.
This colouring matter dyes unmordanted cotton in a boiling bath containing 3 per cent. of colour and 10 per cent. of salt, a full primrose yellow; which is last to light, although not so fast to alkalies and soaping. The principal value of carnotine, however, lies in the fact that dyeing with it is only the first stage in the production of a bright red colour, carnotine red, which is fast to acids and soaping although not perfectly fast to light. To produce this red the cotton is first dyed yellow with carnotine, then it is passed into a cold bath of sodium nitrite containing sulphuric acid, and then into a bath of carnotine red developer, when the red is immediately produced. In a similar way using carnotine orange developer, a fast orange can be produced on cotton.