Patent GB-893821-A (GB)
Title: Improvements in or relating to flushed pigments in powder form
IPC: C09C3/00
Filed: 1959-01-19
Abstract: A process for the production of pigment compositions comprises mixing an aqueous pigment dispersion with a flushing agent which is solid at normal air temperatures, this flushing agent being an ester of a di- or tri-basic carboxylic acid or an alkylbenzene sulfonic acid amide or a mixture of such esters and/or amides, heating the resulting mixture to a temperature at which said flushing agent liquefies and the water is set free from the dispersion, separating the freed water from the mixture and if desired cooling the resulting flushed pigment mixture to solidify the same and pulverizing the mixture.  Suitable flushing agents specified are dicyclohexyl phthalate, a mixture of 2- and 4-methylbenzene-1-sulfonic acid amides, 4-methylbenzene-1-sulfonic acid cyclohexylamide, tricyclohexyl citrate, di-isobutyl tartrate and the glycerin ester of colophony. If desired any water remaining after the separation step can be eliminated by drying in a drying cabinet or by kneading in a vacuum kneading machine.  In examples the process is applied to a copper phthalocyanine blue pigment, a copper phthanocyanine green pigment, a chlorinated phthalocyanine green pigment and a red pigment Naphthol AS. Examples are also given of compositions prepared according to the invention containing ethyl cellulose, a vinyl polymer and an acrylic resin.  The products may be used in lacquers, printing inks and cellulose acetate fibres.ALSO:A process for the production of pigment compositions comprises mixing an aqueous pigment dispersion with a flushing agent which is solid at normal air temperatures this flushing agent being an ester of a di- or tri-basic carboxylic acid or an alkylbenzene sulfonic acid amide or a mixture of such esters and/or amides, heating the resulting mixture to a temperature at which said flushing agent liquefies and the water is set free from the dispersion, separating the freed water from the mixture and if desired cooling the resulting flushed pigment mixture to solidify the same and pulverizing the mixture.  Suitable flushing agents specified are dicyclohexyl phthalate a mixture of 2- and 4-methylbenzene-1-sulfonic acid amides, 4-methylbenzene-1-sulfonic acid cyclohexylamide, tricyclohexyl citrate, di-isobutyl tartrate and the glycerin ester of colophony.  If desired any water remaining after the separation step can be eliminated by drying in a drying cabinet or by kneading in a vacuum kneading machine.  In examples the process is applied to a copper phthalocyanine blue pigment, a copper phthalocyanine green pigment a chlorinated phthalocyanine green pigment and a red pigment Naphthol AS. Examples are also given of compositions prepared according to the invention containing ethyl cellulose, a vinyl polymer ("Vinylite" VMCH) (Registered Trade Mark) and an acrylic resin. The products may be used in lacquers, printing inks and cellulose acetate fibres.ALSO:A process for the production of pigment compositions comprises mixing an aqueous pigment dispersion with a flushing agent which is solid at normal air temperatures this flushing agent being as ester of a di- or tri-basic carboxylic acid or an alkylbenzene sulfonic acid amide or a mixture of such esters and/or amides, heating the resulting mixture to a temperature at which said flushing agent liquefies and the water is set free from the dispersion, separating the freed water from the mixture and if desired cooling the resulting flushed pigment mixture to solidify the same and pulverising the mixture.  Suitable flushing agents specified are dicyclohexyl phthalate a mixture of 2- and 4-methylbenzene-1-sulfonic acid amides, 4-methylbenzene-1-sulfonic acidcyclohexylamide, tricyclohexyl citrate, di-isobutyl tartrate and the glycerin ester of colophony.  If desired any water remaining after the separation step can be eliminated by drying in a drying cabinet or by kneading in a vacuum kneading machine. In examples the process is applied to a copper phthalocyanine blue pigment, a copper phthalocyanine green pigment a chlorinated phthalocyanine green pigment and a red pigment Naphthol AS. p  Examples are also given of compositions prepared according to the invention containing ethyl cellulose, a vinyl polymer and an acrylic resin.  The products may be used in lacquers, printing inks and cellulose acetate fibres.