Phenolic foam

Abstract

A phenolic foam is made by foaming and curing a formable 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 95 / 5 parts by weight. The inorganic filler is at least one selected from a metal hydroxide, a metal oxide, a metal carbonate and metal powder. The phenolic foam has a pH of 5 or more and a water uptake less than 1 kg / m2. 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.

Description

[0001]Phenolic foam is used in insulation applications for construction materials because of its superior thermal insulation and fire resistance characteristics.[0002]It is known that the thermal conductivity of polymeric thermal insulation materials including phenolic foam can change with time. This phenomenon is caused by the gradual diffusion out of gas from inside the foam cells. The gas present inside the foam cells is the blowing agent used in the foaming process. The gas in the foam cells is slowly replaced by air from the atmosphere. As a result, the thermal conductivity of phenolic foam can increase with time.[0003]It is highly desirable to achieve long-term stability for the thermal insulation performance of phenolic foam products. It is believed that one of the causes for the degradation of thermal insulation performance is the reduction in the flexibility of the cell walls of phenolic foam with time. Therefore, an object of the present invention is to impart flexibility ...

AI Technical Summary

Benefits of technology

[0001]Phenolic foam is used in insulation applications for construction materials because of its superior thermal insulation and fire resistance characteristics.

[0002]It is known that the thermal conductivity of polymeric thermal insulation materials including phenolic foam can change with time. This phenomenon is caused by the gradual diffusion out of gas from inside the foam cells. The gas present inside the foam cells is the blowing agent used in the foaming process. The gas in the foam cells is slowly replaced by air from the atmosphere. As a result, the thermal conductivity of phenolic foam can increase with time.

[0003]It is highly desirable to achieve long-term stability for the thermal insulation performance of phenolic foam products. It is believed that one of the causes for the degradation of thermal insulation performance is the reduction in the flexibility of the cell walls of phenolic foam with time. Therefore, an object of the present invention is to impart flexibility to the cell walls and thereby maintain closed cell structure in the phenolic foam. Stable closed cell structure provides a means for maintaining stable thermal conductivity for the phenolic foam over an extended time period.

[0005]Under the above-stated circumstances, the object of the present invention is to provide phenolic foam that has excellent thermal insulation performance, yet also have a higher pH value when compared to conventional phenolic foam. Such a phenolic foam when in contact with metal would have significantly reduced potential to induce metallic corrosion.

Problems solved by technology

It is believed that one of the causes for the degradation of thermal insulation performance is the reduction in the flexibility of the cell walls of phenolic foam with time.

This could cause a problem when metallic materials are in contact with the phenolic foam, as metals could be susceptible to corrosion.

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