| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing color chips useful for lacquer, a coating material, printing ink, cosmetic or the like by repeating plural times such a step of kneading a mixture containing a pigment and binder by a twin- roll mill having a specific rotational speed ratio and clearance between the rolls and of forming the mixture into a sheet material and then by crushing the sheet material. SOLUTION: This method comprises repeating plural times the step of; preparing a mixture of 10 to 90 wt.% of pigment e.g. organic pigment, inorganic pigment or extender and 90 to 10 wt.% of binder of e.g. nitrocellulose, lactic acid acetic acid cellulose, vinyl chloride-vinyl acetate copolymer, acrylic resin, urethane resin or chlorinated rubber; kneading the mixture by a twin-roll mill having a rotational speed ratio of (1 to 1.1) to (1 to 1.3) and gap between the rolls of 1.0 to 3.0 mm; and then forming it into a sheet material, and subsequently by crushing the thus obtained sheet material.
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