Functionally Graded Wood in Fire Endurance with Basic Nitrogen Compounds and Phosphoric Acid

摘要

Fire-retardant wood treatment with fire-retardant chemicals consisting of basic nitrogen compounds and phosphoric acid have been thoroughly examined. The fire retardance and endurance of wood were influenced by the treatment method. Here two treatment methods were compared, heat-pressed treatment method improved these qualities more than heat-dried treatment method. Furthermore, to gain lasting fire retardance, it was considered necessary to react basic nitrogen compounds and phosphoric acid with formaldehyde as in the dicyandiamide-formaldehyde-phosphoric acid or melamine-dicyandiamide-formaldehyde-phosphoric acid system. In the treated wood, the concentration of chemicals gradually decreased as it approached the center. The functional fire retardance could be graded in accordance with the chemical content.