Study On Intumescent Coating And It's Flame Retardant Mechanisms

More and more attention has been focusing towards intumescent coating because it has high thermal insulation against flame and good decorative property. Intumescent coating is also characterized by the ability to rapidly expand to form a stable carbonaceous char when subjected to heat, so extensive investigation and application have been carried out all over the world. In this paper, investigation on J60-N intumescent coating and its flame retardant mechanisms were carried out systematically and extensively.The binders and the flame retardants and several technologies using in intumescent coatings have been selected and the preliminary experiments, such as the simultaneous experiments of several binders and flame retardants and additive agents, were conducted to determine the approximate range of each component in coating, so as to suggest an essential condition for the orthogonal experiment in the following.By L₂₇(3¹³) orthogonal experiment method, five factors and their interactions each other, such as ammonium polyphosphate (APP), melamine (MEL), pentaerythritol (PE), 701 amino resin (701A) and chlorinated paraffin (CP), which affect on the fire retardancy performance of the coating were investigated. Based on the simulated big panel combustion method designed by myself, the fire resistant time which serves as a fire retardancy specification of the coating was measured. The analysis results of extreme difference of each factor and the interaction show that, APP dominates among five factors and APP X PE dominates in interaction. Several optimal formulations that have longer fire resistant time and better repeatability were created by orthogonal experiment. Considering this result, the product has been produced in pilot plant and commercialized in industry. The application of this product indicated that it has physical-chemistry properties prior to others used in industries. This product meets the National Standard of the fire retardancy for first-class products. The experimental results also show that the fire resistant time, the carbonaceous char's height and the flame retardancy increase with the coat film thickness.