Preparation method of benzoxazine containing maleimide bisphenol A-type structure

Abstract

The invention discloses a preparation method of a benzoxazine intermediate containing a maleimide bisphenol A-type structure. The preparation method comprises the steps: (1) adding an aldehyde compound and a solvent into a reaction vessel to uniformly mix at room temperature and normal pressure, then, adding an amine compound into the vessel under stirring, and reacting at the temperature of 0-100 DEG C and normal pressure for at least 10h; (2) pouring the reaction solution into a cleaning solution to clean, filtering and collecting a solid substance, and drying at the temperature of 30-100 DEG C; (3) sequentially adding the obtained solid substance, the aldehyde compound and bisphenol A into a reaction vessel to uniformly mix, heating to 160 DEG C, and reacting for at least 7h under stirring to obtain a brown solid product; (4) dissolving the brown solid product by using a proper amount of ethyl acetate, extracting, collecting an ethyl acetate solution, and then, washing the solution to be neutral by using a 6% sodium bicarbonate solution and tap water; (5) drying the obtained ethyl acetate extracting solution by using anhydrous MgSO4, filtering, and rotatably evaporating the solution at the temperature of 45 DEG C to obtain the yellow solid target product.

Description

Technical field: [0001] The invention belongs to the field of preparation of intermediates of benzoxazine monomers, in particular to a method for preparing a benzoxazine intermediate containing a maleimide bisphenol A structure. Background technique: [0002] The structural formula of the benzoxazine monomer is as follows: [0003] [0004] 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 ...

AI Technical Summary

Problems solved by technology

[0009] 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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