Formaldehyde → Benzoxazines

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The steps include: in a 2 L four-necked glass reactor equipped with a heating mantle, a temperature controller, an electric mixer and a condenser, 200 g of phenolic novolac resin (D) having high proportion of tetra-functional resin monomer and 124.5 g of paraformaldehyde are dissolved thoroughly in the presence of 816 g of a solvent propylene glycol monomethyl ether at 85° C., 169 g of aniline is dropped in the course of 3 hours into the reactor at constant speed by a quantitative pump to proceed the reaction at 85° C. After finishing the dropping addition of aniline, the temperature is kept at 85° C. for aging for 2 hours, then the temperature is raised to 105° C. After water and part of the solvent are removed, a benzoxazine resin solution with 56 wt % solid is obtained. According to gel permeation chromatography (GPC) analysis, the proportion of the tetra-functional resin monomer in this benzoxazine resin is up to 60 area percent (Area %) or more.

Herkunft & Nachweise