Pigment dispersions

Abstract

Abstract HIGHLY CONCENTRATED STABLE BASE PIGMENT DISPERSIONS IN ORGANIC SOLVENTS ARE PREPARED BY ADDING PIGMENT TO AN ORGANIC SOLVENT OR BLEND OF MISCIBLE ORGANIC SOLVENTS IN THE PRESENCE OF SURFACTANT. THE RATE OF PIGMENT ADDITION IS ADJUSTED SO THAT PROPER WETTING OUT OF THE PIGMENT IN THE SOLVENT OCCURS. PIGMENT ADDITION IS CONTINUED UNTIL A HIGH SHEAR MASS IS OBTAINED. THIS MASS IS THEN SUBJECTED TO AGITATION FOR A SUFFICIENT PERIOD OF TIME TO BREAK DOWN PIGMENT AGGLOMERATES AND TO DISPERSE THE PIGMENT THROUGHOUT THE ORGANIC SOLVENT. IN ORDER TO OBTAIN A BASE PIGMENT DISPERSION COMPOSITION THAT CAN BE READILY MIXED WITH ADDITIONAL SOLVENT AND BINDER MATERIAL, THE VISCOSITY OF THE HIGH SHEAR MASS MAY BE REDUCED BY MIXING ADDITIONAL ORGANIC SOLVENT THEREWITH. PIGMENT CONCENTRATIONS OF FROM ABOUT 45% TO ABOUT 90% BY WEIGHT OF THE RESULTING BASE PIGMENT DISPERSIONS ARE OBTAINED. ANY SUITABLE BINDER MATERIAL MAY THEREAFTER BE INCORPORATED IN THE BASE PIGMENT DISPERSION COMPOSITION TO PRODUCE A FINISHED PIGMENT-BINDER DISPERSION COMPOSITION OF HIGH GLOSS AND EXCELLENT DISPERSION CHARACTERISTICS. GREAT ADAPTABILITY IN DETERMINING THE CHARACTERISTICS OF THE FINAL COATING COMPOSITION CAN BE ACHIEVED WHEN THE PIGMENT IS INITIALLY DISPERSED IN A SOLVENT BLEND RATHER THAN A SINGLE ORGANIC SOLVENT. IN ADDITION, THE DESIRABLE PROPERTIES OF THE FINAL COMPOSITION ARE OFTEN ENHANCED BY THE USE OF SUCH A SOLVENT BLEND.

Inventors

• 👤 Frederick E Petke

Bibliographic Details