| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a colorant which has a bright color tone and an improved ultraviolet light resistance by causing fine porous ceramic particles having a specified average particle size to adsorb a dye to reduce the contact surface of the dye with the open air. SOLUTION: Fine porous ceramic particles having an average particle size of 80nm or lower, pref. 50nm or lower, and a void content of 20% or higher are obtd. pref. by dissoving an alkoxide of at least one metal selected from among Si, Kg, Ca, Ba, Zn, etc., in an org. solvent, adding water and a small amt. of an acid or alkali as a catalyst to hydrolyze the alkoxide, and drying the resultant metal oxide sol. The particles are put into water or an alcohol contg. a dye dissolved or dispersed therein in an amt. of 0.1-50wt.% of the particles, stirred at from room temp. to 40 deg.C for 0.5-30hr to cause the particles to adsorb the dye completely, filtered, and dried at 50-150 deg.C, thus giving a colorant comprising the fine particles and the dye adsorbed thereby.</p> |
