Wool Fast Yellow

Indian yellow, fast yellow, azo flavine, brilliant yellow S, curcumine, orange II, palatine light yellow, wool fast yellow, azo acid yellow, azo yellow, etc. ° Solution becomes red or orange red. 

Picric acid is a strong acid, very toxic, soluble in hot water, alcohol, ether, benzene and acetone, and is a fast yellow dye for silk and wool. It attacks common metals, except for aluminium and tin, and produces salts which are very explosive. The explosive power of picric acid is somewhat superior to that of TNT, both with regard to the strength and... 

Metal complexes of tetradentate azomethines, e.g. (199), are reported136 to have very high light-fastness but to be tinctorially weak and dull in hue. Despite this they are of technical interest as very fast yellow to brown pigments. They find no application as dyestuffs, however, because of these deficiencies for example, the chromium complex of (200) gives dull, tinctorially weak dyeings on wool possessing poor wet-fastness properties. 

TARTRAZINE XX TARTRAZINE XXX TARTRAZINE YELLOW TARTRAZOL BPC T.ARTRAZOL YELLOW TARTRINE YELLOW O TRISODIUM 3-CARBOXY-S-HA DROXY-l-p-SULFOPHENYL-4-p-SULFOPHENYLAZOPYRAZOLE TRISODIUM SALT of 3-CARBOXY-5-HYDROXY-1-SULFOPHENYLAZOPY-RAZOLE UNITERTRACID YELLOW TE USACERT YELLOW NO. 5 VONDACID TARTRAZINE WOOL YELLOW XYLENE FAST YELLOW GT Y-4 1310 YELLOW 1409 YELLOW YELLOW LAKE 69 YELLOW NO. 5 YELLOW NO. 5 FDC ZLUT KYSELA 23 ZLUT PIGMENT 100 ZLUT POTRAVINARSKA 4... 

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. 

A number of derivatives of fluorescein are useful dyes. Uranin is the disodium salt of fluorescein. ChrysoUn is a salt of benzyl-fluorescein, which is formed from phthalic anhydride and benzyl-resorcinol. It dyes silk and wool a fast yellow, and is used in cotton dyeing. Eosin is the disodium salt of tetrabromo-fluorescein, which is prepared by the action of bromine on fluorescein. Its dilute alkaline solution is rose-colored, and exhibits an intense yellow-green fluorescence. Other dyes related to fluorescein are tetrabromo-dichlorofluorescein and various ethers of fluorescein and its substitution-products. The dyes of this class produce on silk and wool shades from yellow to reddish yellow, cherry-red, and purple. 

An important discovery was the realization that diaminodiphenyls substituted in the 2,2 -positions are outstandingly suitable for the manufacture of very wash-fast and millingfast wool dyes, while the substantivity toward cellulosic fibers is reduced. A number of important acid wool dyes have been developed on this basis, for example, C.I. Acid Yellow 44, 23900 [2429-76-7] (15). 

Particularly good milling fastness is achieved by die introduction of 4,4 -diam-inodiphenylthio ether as the diazo component, for example, in the yellow wool dye C.I. Acid Yellow38, 25135 [13390-47-1] (19). 

Dyes. In dyeing PES-wool mixtures, disperse dyes are used for the PES component, and acid or metal-complex dyes for the wool. Disperse dyes can soil wool to a great extent. Since they produce poorly fast dyeings on wool, the dyes selected must stain wool as slightly as possible or must be easily removable by a washing step, which may be reductive if necessary. Frequently used dyes are C.I. Disperse Yellow 23, 54, 64 C.I. Disperse Orange 30, 33 C.I. Disperse Red 50, 60, 73, 91, 167, 179 and C.I. DisperseBlue 56, 73, 87. Premixed dyes consisting of disperse and wool dyes are occasionally available. 

Perspiration tests similarly indicated the presence of two dyestuffs. In the alkali solution, the yellow color seemed to be removed almost completely, leaving a pink-colored fabric. In the acidic solution, the yellow dye migrated to the wool, silk, and nylon sections of the multifiber test strips, staining these fibers a bright yellow shade. The pink color seemed to bleed minimally a small amount of color was transferred in the alkali solution tests, but generally this pink color remained comparatively very fast. 

Yellow Dyestuff. The yellow-producing dyestuff is suspected to be an acid dye, primarily because its behavior responses to the A.A.T.C.C. tests parallel those typical of this class of dyes, as outlined by Corbman (17). The poor washfastness, tendency to bleed easily, and fair perspiration fastness exhibited by this yellow component are distinctly like those of the acid dyes. The historic textile, moreover, demonstrates the acid dye s typically excellent resistance to crocking. This yellow color was transferred to wool, silk, and nylon—all of which have an affinity for acid dyes. 

Polar yellow 5G is prepared by condensing p-chloro-m-sulfophenylhydrazine with acetoacetic ester, and coupling the resulting pyrazolone with diazotized p-aminophenol in acetic acid solution. The alkali sensitive dye which is formed is treated at 70°C. with p-toluenesulfonyl chloride, in the presence of soda and 1 mole of sodium hydroxide, to esterify the hydroxyl group. This esterification makes the dye insensitive to alkali and, at the same time, fast to milling on wool. 

Anionic OBA for nylon. Lycra, and wool. Recommended for exhaust or continuous application. Produces a brillinat reddish white with excellent fastness to light and gas fading and resistance to yellowing. 

For a considerable period chrysaniline was the only basic yellow dyestuff, and for this reason was largely used in cottondying. Wool and silk are dyed directly, cotton requires a taunin mordant. The shade produced is an orange-yellow, noteworthy for its fastness to light. 

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