Catechol tannin

Description

One of two general classes of vegetable tannins. The other class is pyrogallol. Catechol tannins contain an organic phenolic compound(s). Examples are cutch, Quebracho, Hemlock bark, Gambier, and Willow bark. Catechol tannins give a greenish-black precipitate with iron salts. They produce leathers that are more resistant to heat and decay than pyrogallols.

Physical and Chemical Properties

Soluble in water, ethanol.

Resources and Citations

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 796

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

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998