Inventors:
Yuan Yu - Nashua NH
Friedrich K. von Gottberg - Cambridge MA
Robert M. Amici - Berlin MA
Paul S. Palumbo - West Newton MA
Assignee:
Cabot Corporation - Boston MA
International Classification:
C09D 1100
US Classification:
106 3165, 106412, 106415, 106419, 106494, 106495, 106496, 106497, 106498, 106484, 106432, 106436, 106450, 106452, 106453, 106455, 106461, 106479, 106480, 106485
Abstract:
Colored pigments having one or more desired parameters and/or properties are described. These parameters and/or properties include: a) a particles size of from about 10 nm to about 300 nm; b) an accusizer number of less than 10 particles/ml of dispersion at 15% solids which are greater than 0. 5 micron; c) a filterability such that when in a liquid medium, 100 ml having 10% solids of the colored pigment filters through a 3 micron nylon absolute filter; d) a colored pigment purity of greater than about 80%, based on extractable material; and/or e) a stability such that the above-described properties do not change by more than 50% at 25 degrees C. for at least one week. Colored pigments having at least one organic group and having one or more of the above-described characteristics is also described as well as a process for preparing surface-modified colored pigments. The process involves combining at least one treating agent and at least one type of colored pigment(s) in a container to form a mixture and subjecting the mixture to high shearing and introducing at least one diazotizing agent to the mixture at least for a portion of time while the high shearing is taking place, and preferably during the entire time that high shearing is taking place, such that a reaction product is formed and contains surface-modified colored pigment(s).
