| 摘要 |
PURPOSE: To produce a baked lead having excellent light resistance, weatherability and bright color and excellent in erasability by an eraser while keeping strength by bringing a pigment precursor into a pigmentation reaction and producing the pigment in inside of open pores of a porous baked lead to produce a pigmented pigment in the open pores. CONSTITUTION: This baked lead contains an organic pigment produced by carrying out a pigmentation reaction on a pigment precursor (e.g.; a basic ingredient such as anthranillic acid, sulfanilic acid, etc., and a coupling ingredient such asβ-naphthol,β-oxynaphthoic acid, etc.) in open pores of a baked lead having the open pores. The open pore size is preferably >=0.1μm and <=0.5μm and the open pore % is >=7%, more preferably >=12%. The method for producing the porous baked lead is to produce at first the baked lead having open pores, impregnate a pigment precursor solution into the open pores and bringing the precursor into a pigmentation reaction in the open pores to obtain the objective porous baked lead. As the lead has high strength, it is very useful as a colored pencil refill for a mechanical pencil.
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