ALL-SEASON IMPREGNATING LIQUID Russian patent published in 1997 - IPC

FIELD: wood preservation. SUBSTANCE: invention is first aimed at enlarging resource of sleeper- impregnation materials with essentially lowered toxicity owing to replacing coal sleeper-impregnation oil with broad fraction (200-460 C) of heavy gas oil produced by coking the cracking distillation residuum. Invention further aims at simplifying impregnating liquid preparation process by way of excluding necessity in compounding two components (in the case of preparing coal oil), their crystallization, and centrifugation to separate crystals, and also possibility to prepare impregnating liquid with all-season temperature from -1 to -22 C thanks to depressor introduced into heavy gas oil fraction, said depressor constituting specified quantity (0.5-3.0%) of cracking distillation residuum. EFFECT: improved performance characteristics of product and enlarged choice of starting materials. 2 tbl