Acid Magenta

In some countries (Great Britain) ammonium nitrate is used with an admixture of triphenylmethane dye, Acid Magenta which inhibits the transformation of one crystalline form into the other at 32°C (Vol. II, p. 454). 

Acid magenta (CX Acid Violet 19) Area increase 110% not adsorbed... 

Acid Magenta. A mixt of di sulfonic and tri-sulfonic acids of pararosaniline, used as a dye or stain. Was proposed for coating crystsof AN to render them non-hygroscopic and thus make them more suitable for use in expls, propellants and fertilizers. Quantities as low as 0,01-0.03% proved to be sufficient for effective waterproofing... 

Whetstone (Ref 1) proposed to add "Acid Magenta" to a satd soln of AN, just before crystn. It has been claimed that this treatment modifies the form of crysts in such a mariner that their agglomeration does not form cakes but leaves them as granules... 

Adding to ammonium nitrate small quantities of Acid Magenta, a tri-sulpho-triamine-methyl-triphenylmethane dyestuff. According to Butchart and Whetstone [7] 0.1% of this dyestuff admixed with a saturated ammonium nitrate solution or 0.03% of the dye added to the crystals forms an effective layer that prevents ammonium nitrate from caking within the temperature range —18 to 32°C. 

Ca stearate 0-0.5% discharge head AN (contg 0.05% acid magenta) 65.0, Ca(OOCH)2 34.9 Ca stearate 0.1%, packed in a tube in the center of which is imbedded a fuse heating device- GuN 60.0, K2S2Ob 31.5, Cl C 8.0 petroleum jelly 0.5%, wrapped in fireproof manila paper and... 

Acid magenta, acid luchsme, last acid red A 10 De colonsed Colour does not return on exposure to air but is restored by per sul phate Tri phenyl- methane Class H-g, IV erg. 5 K (A 3... 

Methyl violet is difficult to convert into sulphonic acid by fuming sulphuric acid a better result is obtained by sulphonation, and subsequent oxidation of the leuco-base. Benzylated violets, however are much easier to sulphonate, especially in form of their leuco-bases, the sulpho-group probably entering the benzene nucleus of the benzyl group. Other acid-violets are obtained by methylation and benzylation of acid magenta. 

They produce magenta shades on wool and are recommended as substitutes for acid magenta on account of their fastness to light and the clearness of the shades obtained. They may also be used for printing woollens prepared with alum and stannic chloride. German Pat. 54116, Oct. 25, 1889. 

The outstanding characteristic of the basic dyes is the brilliance and intensity of their colours. Some of the shades are of such clarity of hue that no other class can compare with them. The intensity is illustrated by a comparison of the dyeing properties of magenta, which is a basic dye, and acid magenta, which has the same molecular structure but has been converted into an acid dye by sulphonation. Whilst 5 per cent of the latter is required to produce a full shade on wool, only 2 to 3 per cent of basic magenta is necessary. The basic dyes are readily soluble in alcohol or methylated spirit. They are not, as a rule, so easily dissolved in water and, unless care... 

The first acid dye was made by Nicholson in 1862, when he sulphonated aniline blue it was known at that time as Bleu de Lyons (Chapter 1). Other basic dyes were subsequently sulphonated to convert them into acid dyes, making them more easily applicable to wool than the parent basic dyes. Acid Magenta (C.I. acid violet 19), formula (1), is obtained by the sulphonation of magenta ... 

The most significant assistant in the application of these dyes is the acid added to the dyebath. Many acid dyes will not exhaust on wool at all unless the dyebath has been acidified. If, for example, wool is boiled gently for half an hour with 5 per cent of Acid Magenta, it is only faintlystained. When 4 to 5 per cent of sulphuric acid is also added, however, the wool is dyed a heavy shade, and exhaustion is virtually complete. Some experiments reported by Lister (J.S.D.C., 1949, 98) show the relationship between acid and exhaustion of Azo Rhodine 2G (C.I. acid red 1) and Xylene Fast Yellow P (C.I. ACID YELLOW 61) on purified wool. 

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