METHOD OF PRODUCING FURFURAL RESIN BASED ON HEMICELLULOSES OF PLANT RAW MATERIAL FOR GLUING WOOD MATERIALS Russian patent published in 2020 - IPC C09J197/00 C13K13/00 C07D307/50 

FIELD: technological processes.

SUBSTANCE: invention relates to production of furfural resin and can be used for gluing of wood materials in production of plywood, wood chip (WCB), wood-fiber boards (WFB) and other purposes. Method of producing furfural resin based on hemicelluloses of plant materials for gluing wood articles involves hydrolysis of plant material with hydrogen chloride. Ground vegetable raw material is saturated with hydrogen chloride from gas-air mixture with concentration of 0.5–25.0 vol.% of hydrogen chloride at temperature of 20–60 °C to content of hydrogen chloride of 35–50 % of weight of dry raw material. After that, hydrolyzate-mass obtained after saturation is dried with air with temperature of 120–350 °C to residual content of hydrogen chloride less than 0.5 % of weight of dry material and final temperature of hydrolyzate-mass of not more than 110 °C. Furfural resin is extracted from the dry hydrolyzate mass by extraction using water or aliphatic alcohols at temperature of 50–80 °C and evaporation of the obtained extract under vacuum till concentration of dry substances is equal to 35–65 %. Then hydrogen chloride is recovered for which part of exhaust gases of drying is used at stage of saturation of vegetal raw materials and cooled other part of exhaust gases of drying is cooled to temperature of 20–40 °C with formation of condensate, followed by subsequent azeotropic salt fractionation of condensate together with fresh hydrochloric acid, wherein the hydrogen chloride obtained during salt fractionation is used at the stage of saturation of vegetable material. Invention enables to obtain a water-soluble furfural resin suitable for gluing wood-based materials in the production of plywood, wood chip (WCB), wood-fiber boards (WFB) and other purposes. Use of furfural resin in pure form or in a hydrolyzate-mass composition enables to obtain WCM with considerably lower content of formaldehyde compared to WCM based on UFR.

EFFECT: materials based on furfural resin have higher water resistance in cold water and preserve their integrity during boiling.

5 cl, 1 dwg, 1 tbl