Dry water-dispersible pigment compositions
AssigneeHercules Incorporated
InventorJohn Guzi, Jr.
Life of this patent
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Abstract
Dry, non-dusting pigment compositions which are water-dispersible and which develop good strength and color values upon stirring in water-borne industrial finish systems are described. The pigment compositions contain 55 to 80% pigment and, by weight of the pigment, from 15 to 45% of certain nonionic dispersing agents and from 10 to 67% of at least one water-soluble cellulose ether which is nonionic in nature and has a viscosity of less than 1000 cps. as measured on a 2% aqueous solution at 25.degree. C. The pigment compositions are preferably prepared by milling the pigment in water in the presence of the nonionic dispersing agent, mixing the milled pigment dispersion with the cellulose ether and then removing the water from the resulting mixture.
Claims10
A dry, non-dusting, water-dispersible pigment composition developing upon stirring in water-borne industrial finish systems good strength and color values, said composition consisting essentially of from 55 to 80% of pigment and, based on the pigment weight, from 15 to 45% of a nonionic dispersing agent of the polyether alcohol type, alkylene oxide-alkylene diamine block polymer type or polyoxyethylene glycol or glycerol ester type and from 10 to 67% of at least one water-soluble, nonionic cellulose ether having a viscosity of less than 1000 cps. as measured on a 2% aqueous solution at 25.degree. C.
A process for preparing a dry, non-dusting, water-dispersible pigment composition developing upon stirring in water-borne industrial finish systems good strength and color values, said process consisting essentially of the steps of:
- forming a homogeneous mixture consisting essentially of milled or homogenized pigment, water, a nonionic dispersing agent of the polyether alcohol type, the alkylene oxide-alkylene diamine block polymer type or the polyoxyethylene glycol or glycerol ester type and at least one water-soluble, nonionic cellulose ether having a viscosity of less than 1000 cps. as measured on a 2% aqueous solution at 25.degree. C.;
- and removing the water from said mixture until a dry composition is obtained, the amount of pigment, dispersing agent and cellulose ether being such as to provide a dry composition consisting essentially of from 55 to 80% of pigment, and, based on the pigment weight from 15 to 45% of the dispersing agent and 10 to 67% of the cellulose ether.
Dependencies are inferred from the claim text.