Two-step milling process for preparing pigmentary copper phthalocyanine
AssigneeE. I. Du Pont de Nemours and Company
InventorHoward Matrick
Life of this patent
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Abstract
Converting crude copper phthalocyanine (CPC) to pigmentary copper phthalocyanine (CPC) by two-stage milling with 5-400% by weight of alum and 0.6-3.7 cc of organic liquid per 100 grams of CPC in the first stage and 1.2-9.8 cc of organic liquid per 100 grams of CPC in the second stage with the total organic liquid being 4-13 cc per 100 grams CPC.
Claims15
A two-stage milling process for preparing pigmentary copper phthalocyanine comprising milling crude copper phthalocyanine with a 5-400% by weight of Al.sub.2 (SO.sub.4).sub.3.15-18 H.sub.2 O based on the crude and 0.6-3.7 cc per 100 grams of copper phthalocyanine of an organic liquid in the first stage, milling said crude further with an additional 1.2-9.8 cc per 100 grams of copper phthalocyanine of an organic liquid in a second stage, the total amount of organic liquid charged in both stages is in the range of 4-13 cc inclusive per 100 grams of copper phthalocyanine, treating the milled copper phthalocyanine with an emulsion of a water-insoluble organic liquid in water with or without a surface-active agent at a temperature of 24.degree.-97.degree. C. for 15 minutes to 10 hours, removing the organic liquid and recovering copper phthalocyanine in pigmentary form.
Dependencies are inferred from the claim text.