Conferring fire alarm, self-extinguishing and flame repellent property - on solids by addn. of thin polymer micro-capsules contg. bromo-fluoroalkane

摘要

Solid materials with a flame point =500 degrees C are given firealarm, or fire-alarm and self extinguishing, or fire-alarm self-extinguishing and flame-repellant properties, by application of >=1 surface layer contg. microcapsules with an outer dia. of 200-260 mu. The walls of the microcapsules consist of a polymer in which the pores have been sealed with a hydrophobic polycondensation prod. of an aromatic polyhydroxy cpd. and an aldehyde; the microcapsules contain a bromofluoroalkane, liquid at room temp., with a critical temp. >=100 degrees C. Audible warning of fire is given in the initial stages of burning. The amt. of CO2 needed for fire extinguishing is about 1/10 of that normally used. The haloalkanes are of low toxicity.