METHOD OF PRODUCING LIGNIN-MELAMINE-PHENOL-FORMALDEHYDE RESIN Russian patent published in 2024 - IPC C08F2/04 C08L101/00 C08G14/10 C08G8/28 

FIELD: chemical or physical processes.

SUBSTANCE: invention relates to a method of producing lignin-melamine-phenol-formaldehyde resin. Disclosed is a method of producing lignin-melamine-phenol-formaldehyde resin, which is carried out by mixing phenol, formaldehyde and a lignin-containing substance in an alkaline medium, wherein melamine is additionally used, and lignin-containing substance used is sodium lignosulphonate; formalin and sodium lignosulphonate are dosed into the reactor, then the reaction mixture is heated to 70–90 °C and held for 1–3 hours, then the content is cooled to 30–50 °C, then alkali and phenol are dosed and heated to 70–90 °C, then holding the reactor contents for 1–6 hours, after holding the reaction mixture is cooled to 40–65 °C and melamine is dosed, the mixture is heated to 70–80 °C and held for 1–4 hours; wherein phenol, formalin and alkali are dosed in molar ratio as 1:(1.5–3):(0.02–0.2), respectively, sodium lignosulphonate and melamine are also prepared in amount of 0.1 to 35% and 0.1 to 20% of the total weight of the prepared phenol, formalin and alkali.

EFFECT: obtaining lignin-melamine-phenol-formaldehyde resin, which provides high strength and water resistance of the adhesive joint.

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