METHOD FOR OBTAINING CARBAMIDE MELAMINE FORMALDEHYDE RESIN Russian patent published in 2015 - IPC C08G12/12 C08G12/38 C08L61/30 C09J161/30 

FIELD: chemistry.

SUBSTANCE: invention relates to method for obtaining carbamide melamine formaldehyde resin, carbamide melamine formaldehyde resin, obtained in this way, application of such resin, composite material, containing said resin, and product, containing such composite material. Method is characterised by step-by-step condensation of carbamide and formaldehyde and further co-condensation of obtained prepolymer with melanine. Carbamide-formaldehyde concentrate can be used as formaldehyde raw material for obtaining carbamide melamine formaldehyde resin. Condensation with carbamide is realised in three steps, carrying out portioned introduction of carbamide. The process is realised in media with variable acidity and with heating. Deionised water can be used as viscosity regulator. Borax can be added into reaction mixture at the stage of co-condensation with melamine.

EFFECT: obtaining resin, which has high dry residue, insignificant content of free formaldehyde, and which is stable in storage, has short period of gelatinisation and excellent physical and mechanical properties, can be used as chemical curing agent, i.e. for production of wood particleboard and fibre boards and other composite materials.

15 cl, 1 tbl, 7 ex