ULTRA-LOW FORMALDEHYDE RELEASING UREA-FORMALDEHYDE RESIN WITH NEW STRUCTURE AND PREPARATION METHOD THEREFOR

摘要

Disclosed are an ultra-low formaldehyde releasing urea-formaldehyde resin with a new structure and a preparation method therefore. The ultra-low formaldehyde releasing urea-formaldehyde resin comprises formaldehyde, urea, a long-chain polyaldehyde prepolymer, or one or more modifiers, and the preparation method follows a process route of weak base-weak acid-weak base. In the method, the long-chain polyaldehyde prepolymer is introduced to involve in the reaction for the urea-formaldehyde resin, a stable alkylether structure is generated when the prepared resin is cured, and a remaining aldehyde group on a side chain of the long-chain polyaldehyde prepolymer after reaction replaces free formaldehyde, thereby facilitating the cross-linking, and ensuring the bond strength and water resistance of the urea-formaldehyde resin with an extremely low F/U molar ratio. The urea-formaldehyde resin prepared through the method has the advantages that the content of free formaldehyde is low, the process is simple, the bond strength is high, and the formaldehyde release of plates prepared using the binder reaches an average value of equal to or lower than 0.3 mg/L of F four-star level of Japan.