METHOD OF PREPARING MIXING OF WATER-SOLUBLE MULTIHYDRIC ALCOHOL BORIC ESTERS Russian patent published in 2001 - IPC

FIELD: chemical industry. SUBSTANCE: described is method of preparing mixture of water-soluble multihydric boric esters which are hydrolysis resistant. Light fraction of high-boiling by-product with boiling temperature from 150 to 180 C is esterified at residual pressure of 100-200 mm Hg at weight ratio of boric acid to high-boiling by-products to water of (0.035- 0.40): 1:1, respectively, and process is carried out in two reactors. In first reactor esterification is carried out at 104-110 C followed by hydrolysis and separation of boric acid crystals precipitated during hydrolysis on filter installed on reactor bottom and recycle of separated crystals to process, and excessive amount of water, readily volatile organic matter and formaldehyde are distilled off from filtrate in second reactor. EFFECT: improved quality of the product, lower fire hazard of process and simpler preparation process. 2 ex, 1 tbl