PYROLYSIS-BASED MATERIAL RECOVERY FROM MOLDING RESIN FOR ELECTRONIC PARTS

Pyrolysis-based technology for the epoxy resin compounds (molding resi n) used for molding electronic components has been studied for the pur pose of recovering useful materials and reusing them. The molding resi n contains silica filler (70-85% by weight) and flame retardant consis ting of bromine compounds and antimony oxides. This study has clarifie d those pyrolysis conditions best suited to reduction of the impuritie s (carbon, antimony, and ionic substances) in the recovered silica til ler This has contributed to the development of a practical pyrolysis t echnology in which a roller kiln-type furnace is used to recover high- purity silica filler. The recovered silica was sufficiently pure to be employed as an inorganic tiller in epoxy resin compounds to be used a s cast-insulating materials and original molding resins. The combustio n exhaust gas generated in the pyrolysis of the molding resin has been successfully treated by a secondary combustion method that decomposed organic bromine compounds in the gas to a safe level, and it converte d antimony bromides to antimony oxides, which could then be collected by a dry recovery process at a useful purity.