PRODUCTION OF WATER-INSOLUBLE TANNIN AGENT

摘要

PURPOSE:To obtain a tannin agent with good activity by a method wherein triacetylgalloyl chloride is reacted with a polysaccharide deriv. in the presence of quinoline and the reaction mixture is dropped in a liq. and only phenolic hydroxyl groups in the reaction product are deacetylated. CONSTITUTION:An acid chloride such as triacetylgalloyl chloride is reacted with an org. solvent-soluble polysaccharide deriv. such as carboxymethyl cellulose in an org. solvent in the presence of quinoline. Then, this reaction liq. is dropped into a polar solvent or water to precipitate the reaction product. Then, only acetyl groups bound with phenolic hydroxyl groups in the reaction product are deacetylated by a relatively weak deacetylation. A tannin agent with good tannin activity is thus produced simply and with a safe process.