Difference between revisions of "Carminic acid"
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== Description == | == Description == | ||
| − | A bright red or dark purple brown powder. Carminic acid is the primary colorant in [ | + | A bright red or dark purple brown powder. Carminic acid is the primary colorant in [[cochineal]] dyestuff. It is a tricyclic compound that is extracted from the dried insects ''Coccus cacti'' with water. Carminic acid changes colors with acidity. It is a bright red in neutral solutions, below pH 4.8, it is yellow and above 6.2, it is a deep violet color. Carminic acid is used as a lake pigment for oil colors, as a red dye for photography and as a textile colorant. |
== Synonyms and Related Terms == | == Synonyms and Related Terms == | ||
Revision as of 14:09, 12 January 2014
Description
A bright red or dark purple brown powder. Carminic acid is the primary colorant in Cochineal dyestuff. It is a tricyclic compound that is extracted from the dried insects Coccus cacti with water. Carminic acid changes colors with acidity. It is a bright red in neutral solutions, below pH 4.8, it is yellow and above 6.2, it is a deep violet color. Carminic acid is used as a lake pigment for oil colors, as a red dye for photography and as a textile colorant.
Synonyms and Related Terms
Natural Red 4; CI 75470; ácido (Esp.); acido carminico (It.); ácido carmínico (Port.)
Other Properties
Soluble in water,ethanol, concentrated sulfuric acid. Insoluble in ether, benzene, chloroform. UV max in water = 500 nm.
| Composition | C22H20O13 |
|---|---|
| CAS | 1260-17-9 |
| Melting Point | 136 (dec) |
| Molecular Weight | mol. wt. = 492.39 |
Hazards and Safety
Combustible.
Mallinckrodt Baker: MSDS
Authority
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 1891
- Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980
- F. Crace-Calvert, Dyeing and Calico Printing, Palmer & Howe, London, 1876
- Sigma Dyes, Stains and Natural Pigments, Infrared Library, Nicolet, 1991-1995 Comment: OMNIC: formula= C22H20O13, CAS= 1260-17-9