反应详情

A mixture of 100 parts of the crude copper phthalocyanine mentioned in Example 11, 200 parts of a chlorine-free crude copper phthalocyanine which has been produced from o-phthalodinitrile and copper-I chloride by the solvent process, and 7.5 parts of a mixture of CuPc-- CH2N(C2H5)2 ]n, where n = 3.4 is milled for 20 hours in a ball mill. The milled material consists of agglomerates of up to 150 μm in size, made up of primary particles of 0.2 μm mean size. The BET surface area is 5 m2 /g. 50% of the agglomerates are of size 10 μm or above. The milled material is introduced into a 20-fold amount of water and is stirred hot until the salt has dissolved. The warm suspension is filtered. The moist filter cake is introduced into 400 parts of tetrahydrofuran and 200 parts of 6 percent strength sodium hydroxide solution and the mixture is stirred for 5 hours at the reflux temperature. The tetrahydrofuran is then distilled off and the pigment is filtered off and washed. 300 Parts of a copper phthalocyanine pigment which is very suitable for coloring surface coatings are obtained. Specific surface area, measured by the BET method: 74 m2 /g. The tinctorial strength is 6% greater than that of the comparative pigment obtained according to (b).