| 摘要 |
PROBLEM TO BE SOLVED: To obtain a tannin composition excellent in stabilities to heat, air and light, and useful for a fiber processing, a tanning agent, an antirust agent, a coating material, a medicinal use, etc., by blending tannin with a specific amount of a phosphoric acid compound or a phosphorus oxyhalogenide, etc. SOLUTION: This tannin composition excellent in stabilities to heat, air and light, without causing a discoloration, and useful for a fiber processing, a tanning agent, an antirust agent, a coating material, a medicinal use, etc., is obtained by blending a tannin such as a condensed-type (catechol) tannin, a hydrolyzed-type (pyrogallol) tannin and gallic acid, m-galloyl gallic acid and a polyphenol, a flavonoide, catechines, etc., with a phosphoric acid such as a linear polyphosphoric acid such as orthophosphoric acid, tripolyphosphoric acid, etc., and a cyclic phosphoric acid such as trimetaphosphoric acid, tetrametaphosphoric acid, etc., and an ultraphosphoric acid, etc., or a phosphorus oxyhalogenide in an amount of 1/6-12mol in terms of trimetaphosphoric acid per 1mol tannin. |
