| abstract |
A phenolic foam is made by foaming and curing a foamable phenolic resin composition that comprises a phenolic resin, a blowing agent, an acid catalyst and an inorganic filler. The blowing agent comprises a blend of chlorinated aliphatic hydrocarbon containing 2 to 5 carbon atoms and an aliphatic hydrocarbon containing from 3 to 6 carbon atoms mixed in a ratio of 60/40 to 5/5 parts by weight. The inorganic filler is at least one selected from a metal hydroxide, a metal oxide, a metal carbonate and a metal powder. The phenolic foam has a pH of 5 or more and a water uptake less than 1 kg/m 2 . A phenolic foam with a higher pH value compared with conventional phenolic foam reduces corrosion risk when in contact with metallic materials. The phenolic foam maintains excellent long-term stable thermal insulation performance, low water uptake and fire resistance performance and by using the said blowing agent, does not harm the environment as an ozone or global warming depleting material. |