INDIGO

PRODUCT IDENTIFICATION

CAS NO. 482-89-3

INDIGO

EINECS NO. 207-586-9
FORMULA C16H10N2O2
MOL WT. 262.26
H.S. CODE 3204.15.1000
TOXICITY Mouse LD50 (Oral): > 32gm/kg
SYNONYMS Indigo Blue; Indigotin; C.I. Vat Blue 1; C.I. 73000; C.I. Pigment Blue 66;
[delta(2,2')-Biindoline]-3,3'-dione; delta(2,2')Bipseudoindoxyl; 2-(1,3-Dihydro-3-oxo-2H-indol- 2-ylidene)-1, 2-dihydro -3H-indol-3-one; 2,2'-Bi(2,3-dihydro-3-oxoindolylidene); 2;2,3,2',3'-Tetrahydro-3,3'-dioxo-2,2'- biindolylidene; 2,3,2',3'-Tetrahydro-3,3'-dioxo-2,2'- biindolylidene; Other RN: 11129-41-2; 12000-74-7; 12626-73-2; 93660-98-1; 136797-30-3; 210488-46-3; 908005-94-7;
SMILES C1(=C2\C(c3ccccc3N2)=O)\C(c2ccccc2N1)=O

CLASSIFICATION

Coloring Agent,  Redox Indicators, Stains and Dyes

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE Dark blue powder or granule
MELTING POINT 390 - 392 C (Decomposes)
BOILING POINT  
SPECIFIC GRAVITY  
SOLUBILITY IN WATER Practically insoluble (13.4 mg/l), Practically insoluble in dilute acids, alcohol and ether. Soluble in conc. H2SO4, aniline, nitrobenzene, chloroform and glacial acetic acid.
AUTOIGNITION  
pH  
VAPOR DENSITY  
log Pow 3.72 (Octanol-water)
VAPOR PRESSURE 9.00E-13 (mmHg at 25 C)
HENRY'S LAW 5.01E-14 (atm-m3/mole at 25 C)
OH RATE 8.26E-11 (cm3/molecule-sec at 25 C Atmospheric )
NFPA RATINGS

Health Hazard: 2, Fire: 0, Reactivity Hazard: 0

REFRACTIVE INDEX

 

FLASH POINT

 

STABILITY Stable under ordinary conditions

GENERAL DESCRIPTION & EXTERNAL LINKS

Indigo is a component of blue vat dye naturally obtained from plants like genus Indigofera and Isatis tinctoria. It is now produced synthetically. The key functional group in indigo is C6H4(NH)C(O=)C=, called indogen. It is insoluble in water but soluble in hot aniline and hot chloroform. It become water soluble and colorless form when reduced in the presence of an alkali, which makes easy to dye. Subsequent oxidation process is required to get the target color. Dying is the oxidation process of the fabric. After the fabric is dyed, the dye revert to water insoluble form. There is a solubilized water-soluble vat dye which does not need  the presence of alkali, and thus can be applied to dye animal fibres like wool and silk. Vat dyes are applied particularly to cotton and and rayon where high wash and boil fastness required. Indigo is used in mainly for dyeing heavy blue to grayish purple blue shades for work clothes. It is also used in printing inks and paints. Examples of vat dyes are indigo, thioindigo, indanthrone.

Wikipedia Linking: http://en.wikipedia.org/wiki/Indigo, http://en.wikipedia.org/wiki/Indigo_dye

http://www.madehow.com/
Indigo, or indigotin, is a dyestuff originally extracted from the varieties of the indigo and woad plants. Indigo was known throughout the ancient world for its ability to color fabrics a deep blue. Egyptian artifacts suggest that indigo was employed as early as 1600 B.C. and it has been found in Africa, India, Indonesia, and China. The dye imparts a brilliant blue hue to fabric. In the dying process, cotton and linen threads are usually soaked and dried 15-20 times. By comparison, silk threads must be died over 40 times. After dying, the yarn may be sun dried to deepen the color. Indigo is unique in its ability to impart surface color while only partially penetrating fibers. When yarn died with indigo is untwisted, it can be seen that the inner layers remain uncolored. The dye also fades to give a characteristic wom look and for this reason it is commonly used to color denim. Originally extracted from plants, today indigo is synthetically produced on an industrial scale.....

http://faculty.bennington.edu/
Indigo is a vat dye, meaning that the colorant itself (that is, pure indigo) is not soluble in water and therefore cannot be used directly to color fabric. This is because a dye must penetrate the fibers of a material in order to produce an effective color; they cannot be simply applied to the surface like a paint. So to use indigo to dye fabrics, it must in a converted to a compound that readily dissolves in water. In traditional dyeing procedures, the reaction to produce the soluble form of the dye took place in open vats, hence the term, vat dye....

SALES SPECIFICATION

APPEARANCE

Dark blue powder (or granule)

CONTENT

94.0% min

RESIDUE ON IGNITION

1.0% max

MOISTURE

0.8% max

IRON

0.5% max

PARTICLE SIZE

96.0% min (60 mesh)

TRANSPORTATION
PACKING  
HAZARD CLASS 3 (6.1)
UN NO.

3079

SAFETY INFORMATION

HAZARD OVERVIEW

Causes skin irritation. Causes serious eye irritation. May cause respiratory irritation.

GHS

 

SIGNAL WORD Warning

PICTOGRAMS

HAZARD STATEMENTS

H315-H319-H335

P STATEMENTS

P261-P305 + P351 + P338

EC DIRECTIVES

 

HAZARD CODES

RISK PHRASES

36/37/38

SAFETY PHRASES

26-36