| 摘要 |
PURPOSE:To provide the subject material consisting mainly of silicon carbide, high in transparency in the visible ray region, giving high absorption performance in the ultraviolet ray region, also excellent in corrosion resistance, thus useful as e.g. an ultraviolet shielding material for cosmetics, clothes, coatings or building structures. CONSTITUTION:The objective material consists mainly of silicon carbide, pref. containing >=80wt.% of silicon carbide. For the silicon carbide, white or transparent one containing each <=0.1wt.% of free carbon and transition metal compound is preferable. To obtain such silicon carbide, it is recommended that a raw material therefor be treated with an acid such as hydrochloric acid to remove the transition metal compound contained and treated under heating at 15-95 deg.C to remove the free carbon contained. The crystal form of this silicon carbide is pref. 2H, 4H or 6H in terms of the transparency in the visible ray region. |
