Aluminum stearate

Description

A hard, thermoplastic white powder prepared from tallow and alum. Aluminum stearate forms gels with turpentine, mineral spirits, and oils. It has been used as a drier, thickener, emulsifier, and matting agent in paints and varnishes although excess amounts produce soft, noncohesive films. Aluminum stearate is also used to waterproof fabrics, ropes, paper, leather, concrete, and stucco. It is used as an ingredient in photographic emulsions.

Synonyms and Related Terms

aluminum tristearate; octadecanoic acid aluminum salt; stearic acid aluminum salt; aluminum stearate white (AAT); stéarate d'aluminium (Fr.); Daiwax WA1; Metaspa XX; Rofob 3

Other Properties

Soluble in ethanol, benzene, turpentine and mineral oils.

Insoluble in water.

Composition	Al(C18H35O2)3
CAS	637-12-7
Melting Point	117-120
Density	0.99-1.070
Molecular Weight	mol. wt. = 877.41
Refractive Index	1.49

Authority

• R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966

• Reed Kay, The Painter's Guide To Studio Methods and Materials, Prentice-Hall, Inc., Englewood Cliffs, NJ, 1983

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 48

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: Entry #379

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000