Environment-protective urea-formaldehyde resin with novel structure as well as preparation method and application thereof

Abstract

The invention discloses an environment-protective urea-formaldehyde resin with novel structure as well as a preparation method and an application thereof. The environment-protective urea-formaldehyde resin with novel structure is prepared from formaldehyde, carbamide, performed polymer of the carbamide and dialdehyde and one or more modifying agents according to the process steps of weak base, weak acid and weak base. In the method, the performed polymer of the carbamide and dialdehyde is introduced in the reaction of matrix resin to prepare resin and generate stable alkyl ether structure (-CH2n-O-CH2n-) so as to reduce the content of methylene ether link in the resin, and meanwhile, the introduction of polyfunctional radicals enhances the degree of crosslinking of the resin, therefore, on the premise of ensuring the cementation strength and the water resistance of the resin, the formaldehyde emission of sheet materials in use is greatly reduced. The urea-formaldehyde resin prepared by the method has the advantages of low free formaldehyde content, low cost, simple process and favorable cementation strength. The formaldehyde emission of sheet materials manufactured by the sizing agent reaches the standard of E0 grade.

Description

technical field [0001] The invention relates to a preparation method and application of a novel structure environment-friendly urea-formaldehyde resin, and the prepared adhesive is especially used in the wood processing industry. Background technique [0002] In 2008, the output of my country's wood-based panels was about 94.09 million m 3 , has risen to become the world's largest producer of wood-based panels, and has also become the world's largest producer of wood adhesives, especially urea-formaldehyde resin adhesives. In 2008, the export volume of my country's wood-based panels was 7.17 million m 3 , nearly 18.36% lower than the same period in 2007. This is mainly due to the increasing awareness of environmental protection and the gradual improvement of environmental protection standards in more and more countries. They have begun to impose strict requirements on the release of harmful chemicals from wood-based panels and other wood products, especially the release of...

AI Technical Summary

Problems solved by technology

WO94/04584 reacts dialdehyde with formaldehyde, urea and amine compounds under acidic conditions, and the resulting cyclic urea structure improves the physical and mechanical properties of the resin, but the free formaldehyde content of

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