| 摘要 |
PURPOSE:To use a concd. sulfuric acid contg. nitrogen oxides as the concd. sulfuric acid when thermally expandable graphite is produced. CONSTITUTION:When graphite powder dispersed and slurried in concd. sulfuric acid is treated with peroxomonosulfuric acid produced by the action of hydrogen peroxide having >=30% concn. and the concd. sulfuric acid at 15-60 deg.C to produce thermally expandable graphite, concd. sulfuric acid contg. >=25mg/kg (expressed in terms of NO3<->) nitrogen oxides is used as the concd. sulfuric acid. An arom. hydroxy compd., an arom. amino compd., indole or one of derivs. of these compds. is added to the concd. sulfuric acid and this concd. sulfuric acid is mixed with the hydrogen peroxide. The objective thermally expandable graphite can be economically produced using a low-cost concd. sulfuric acid contg. nitrogen oxides. |
