| 摘要 |
A form of the disazo pigment C.I. 20040 having the formula 30% of <IMAGE> +TR <IMAGE> IS SHOWN HAVING IMPROVED COVERING POWER, IMPROVED FLUIDITY IN LACQUER SYSTEMS AND HIGH LUSTER, WHICH IS CHARACTERIZED BY A SPECIFIC SURFACE OF 10 - 20, PREFERABLY 12 - 17 M2/G AND A MAXIMUM IN GRAIN DIAMETER DISTRIBUTION BETWEEN 500 AND 1000 NM, AT LEAST 30 % OF ALL GRAINS HAVING A DIAMETER OF FROM 500 TO 1000 NM AND LESS THAN 25% OF ALL GRAINS HAVING A DIAMETER OR MORE THAN 1000 NM. This new pigment is obtained by isolating the pigment, after coupling, by stirring it out with alkali and, after having filtered it off and washed until neutrality, heating it to temperatures above 100 DEG C with an organic solvent which is immiscible with water or miscible with water to a limited degree only.
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