Lithol red

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Description

[BASF] A trademark for a series of bright red, metallic salts of a synthetic azo dye. First patented in 1899 by Paul Julius (BASF), Lithol reds are made by combining Tobias acid (2-naphthylamine-1-sulfonic acid) and beta-naphthol. Variations in colors are obtained by forming the salts with sodium, barium, calcium, and strontium cations. Lithol reds are inexpensive and widely used in printing inks, crayons, enamels, stationery, and industrial paints. They are also used as a colorants in some plastics. Lithol reds are not lightfast in sunlight and have only been used in student grade artists paints.

- Na salt: yellowish red, PR 49, CI 15630, water soluble 
- Ba salt: bluish pink, PR 49:1, CAS 1248-18-6
- Ca salt: bright red, PR 49:2, CAS 1103-38-4
- Sr salt: purplish red, PR 49:3, CAS 1103-39-5

Synonyms and Related Terms

Lithol toner; Pigment Red 49; CI 15630; 1-sulfo-beta-naphthalene-azo-beta-naphthol; Harrison Red

FTIR

PR49-1 Barium Lithol red.jpg


Other Properties

Poor lightfastness

Composition C20H14N2O4S

Hazards and Safety

May cause allergic reactions. May be contaminated with cancer causing chemicals.

Additional Information

º H. A. L. Standeven, "The History and Manufacture of Lithol Red, A Pigment Used by Mark Rothko in his Seagram and Harvard Murals of the 1950s and 1960s" Tate Papers, Issue 10, 2008. Link

º B.Berrie, S.Q.Lomax, "Azo Pigments: Their History, Synthesis, Properties and Use in Artists' Materials" in Studies in the History of Art, No.57, National Gallery of Art, Washington DC, 1997.

Sources Checked for Data in Record

  • R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
  • Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
  • 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
  • Thomas Gregory, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 3rd ed., 1942
  • Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979