Development of Lightweight Fire-resistant Putty

In the buildings, when the various types of cables and pipes are installed, the through-holes (openings) will be created at the wall or floor which divides the rooms or the machines. If these openings are not sealed properly for the fire protection, the material such as a cable jacket gets burned like fuse and the fire will spread to the next room. Therefore, the opening filling material requires the fire-resistant property as per the Building Standards Act and it is mandatory to take fire protection measures using the material and construction method which obtained a public certification. A typical construction method is to fill the openings with putty which has a fire-resistant property (Figure 1). This fire-resistant putty consists of resins such as a liquid rubber or oil, inorganic filler and a flame retardant material. There are curable and non-curable putties after construction. Curable putty can hold the openings firmly after construction, but because the dismantling is difficult, there is a drawback that it cannot cope with the re-construction associated with renovation of building or expansion of the equipment (cable re-installation). On the other hand, the contractor prefers non-curable putty because the dismantling and the re-construction for the cable re-installation are easy. Because of the large amount of flame retardant material which has large specific gravity to maintain enough fire-resistant property, many non-curable putty products have large specific gravity and are heavy in comparison to curable putty. In the fire-resistant measures at the high elevation place such as the ceiling or the narrow space, the heavy putty has the disadvantage for carrying and construction so there is a need to develop the lightweight putty. In addition, several requirements listed below were considered. Development of Lightweight Fire-resistant Putty