The Influence of a Fire-Retardant Undercoat on the Burning Characteristics of a Combustible Topcoat

摘要

The objective of the research is to develop an interior, fire-retardant submarine paint with special performance requirements not present in currently available paints. A direct consequence of this investigation was the development of a general method for the introduction of fire retardancy into a combustible coating system without modification of the paints themselves. This was achieved by use of a thin flame-quenching undercoat in combination with the regular coating system. The fire-retardant undercoat contains high proportions of chlorinated paraffin and antimony oxide which interact under the influence of the heat to produce the powerful flame-quenching intermediate. By concentrating these fire-retardant additives in an undercoat, they are much more effective than when dispersed throughout the whole coating system. Although these fire-retardant systems will burn under the influence of an extraneous flame or fire, the burning paint film will immediately self-extinguish when this ignition source is eliminated or when that part of the film directly exposed to the fire is consumed. This performance was obtained even when four or five coats of a combustible paint were applied over only one fire-retardant undercoat. However, since these paints will be used only on noncombustible substrates, their burning characteristics were evaluated only on these types of materials, and their burning characteristics on combustible substrates were not evaluated. Although this investigation was limited to water-based paints to prevent contamination of the submarine's atmosphere with toxic organic solvents, this approach to fire retardancy appears to be applicable to any paint system. (Author)