Naphthol reds
Description
A general class of azo-type organic colorants. Naphthol pigments contain a backbone of 2-hydroxy-3-naphthanilide and include many shades of red and some oranges. They were first patented in 1911 and sold as Grela Reds but did not become popularly used until the 1930s when they were produced by IG Farben (Berrie and Lomax 1997). Later, a series of naphthol reds, called American Naphthol Reds, was introduced to the United States in the 1940s (Berrie and Lomax 1997). About 6% of the red colorants used in 1985 were naphthol pigments. They provide good tinting strength and good lightfastness, but can bleed when exposed to organic solvents. Naphthol reds are used to color plastics, automotive finishes, architectural paints, pencils, crayon, printing inks and inexpensive artists oil paints and watercolors.
See also Naphthol pigments and Beta naphthol pigment.
Synonyms and Related Terms
naphthol dye; azoic dye; Naphthol Red; Permanent Carmine; Grela Red; napthol dye (sp); hydroxynaphthoic anilide; Naphtol Anilid Saure (Deut.); Naphtol AS (Deut.); pigment à base de naphtol (Fr.);
FTIR Spectra Information
| CI number | Pigment name | Manufacture(number) |
|---|---|---|
| PR005 | monolite red CB | unknown |
| PR009 | unidentified | Kremer(23290) |
| PR017 | naphthol red medium | Sun(235-7515) |
| PR022 | naphthol red light | Sun(235-7511) |
| PR022 | naphthol red light shade | Magruder(ra1307-dc) |
| PR023 | naphthol red dark | Sun(235-7575) |
| PR146 | naphthol red FFB | Magruder(ra1308-dc) |
| PR170 | naphthol red | Sun(235-0170) |
| PR170 | naphthol red | Kremer(23290-a) |
| PR266 | naphthol red medium shade | Magruder(ra1014-dc) |
| PR268 | naphthol red warm light shade | Magruder(ra1012-dc) |
| PR269 | naphthol red bluish dark shade | Magruder(ra1087-dc) |
Physical and Chemical Properties
Resistant to acid, alkali and soap.
Resources and Citations
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993 Comment: Napthol AS = azoic coupling component
- Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
- Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985
- Fairchild's Dictionary of Textiles, Phyllis G.Tortora, Robert S. Merkel (eds.), Fairchild Publications, New York City, 7th edition, 1996
- Encyclopedia Britannica, http://www.britannica.com Comment: "Chemical Compound." (Accessed 13 May 2004). gives date of first use as 1912
- B. Berrie, S.Q. Lomax, 'Azo Pigments: Their History, Synthesis, Properties and Use in Artists' Materials', Studies in the History of Art , National Gallery of Art, Washington DC, No. 57, 1997 Comment: patented 1911