| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for preparing a fired lead for color pencil comprising a fired lead impregnated with an ink excellent in stability with time and mechanical strength, that is, flexural strength, tensile strength, impact strength and the like in addition to sufficient color developability and drawn line density. SOLUTION: A formulated composition comprising at least an extender and an organic vehicle is kneaded, extrusion molded and fired in a non-oxidative atmosphere to form a first fired lead comprising, as a binder, carbon formed by carbonization of the organic vehicle. The first fired lead is heated in an oxidative atmosphere to oxidatively remove the carbon binder to form a second fired lead. The second lead is filled with a perhydropolysilazane-containing liquid in its voids, fired in an inert atmosphere such as a nitrogen atmosphere or the like or in an ammonia gas atmosphere at a temperature of at least 300 deg.C and not higher than 600 deg.C, packed densely in an heat-resistant container and fired again in an inert atmosphere such as a nitrogen atmosphere or the like or in an ammonia gas atmosphere at a temperature of higher than 600 deg.C to form a third fired lead, which is filled with an ink in its voids.
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