Method for preparing benzoxazine intermediate containing triazine structure

Abstract

The invention provides a preparation method of triazine structure containing benzoxazine intermediate, which sequentially includes: (1) performing synthetic reaction of aldehyde compound and amine compound at a molar ratio of at least 1:1 which includes adding aldehyde compound and solvent of at least one of clean water, methanol, ethanol, isopropanol, and ethyl acetate into a reactor at the roomtemperature under the normal pressure to obtain mixed solution with aldehyde mass concentration of no greater than 95%, adding amine compound while stirring, and reacting at 0-100 DEG C under the normal pressure for at least 15 minutes to obtain the reactant liquor; (2) pouring into the cleaning solution, stirring and cleaning, and filtering to collect solid substance, or directly filtering the reactant liquor to collect the solid substance; and (3) drying the solid substance obtained in step (2) at 30-100 DEG C.

Description

technical field The invention belongs to the field of preparation of intermediates of benzoxazine monomers, in particular to a preparation method of intermediates of benzoxazines containing a triazine structure. Background technique The structural formula of the benzoxazine monomer is as follows: The benzoxazine monomer undergoes ring-opening polymerization reaction under appropriate conditions to generate a benzoxazine resin with a structure similar to that of a phenolic resin. The essential difference between benzoxazine resin and ordinary phenolic resin is that no small molecules are released during the molding and curing process, and the product has low porosity and close to zero shrinkage. At the same time, benzoxazine resin has the same heat resistance and flame retardancy as phenolic resin, and it is possible to carry out molecular design in the way of epoxy resin and have better physical and mechanical properties than epoxy resin, which has aroused people's interes...

AI Technical Summary

Problems solved by technology

As can be seen from the above, the recovery process is complicated, and the use of a large amount of toxic organic solvents is a restrictive factor in the current production process of triazine intermediates; and the reaction temperature is generally high, which will lead to high energy consumption in production and will inevitably limit its production. Application and promotion

The method that Ishida provides not only synthetic reaction temperature is high, and technology is loaded down with trivial details, and productive rate is low (productive rate 62%); Although the method that Espinosa provides is simple, with the bigger toluene of toxicity as solvent, and productive rate is low (productive rate 60%) %); Although the method that Giumanini provides is high in yield (using toluene as solvent, yield 95%, without solvent, yield 94.6%), there is still the problem of polluting the environment, if the solvent that pollutes the environment is not used, then need to pass through the environment Recrystallization of hexane-benzene mixed solvent system removes excess paraformaldehyde, which is not convenient for large-scale synthesis

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