Pigment composition, process for manufacture, and organic materials containing the same

A solid pigment composition for the pigmentation of an organic material (e.g. alkyd resins, lithographic varnishes, printing inks, nitrocellulose or polyvinyl chloride) comprises a finely divided organic or carbon black pigment and resinous substance which is soluble to the extent of at least 5% by weight in the organic material, the composition containing at least 60% by weight of pigment and the volume concentration of pigment in the composition under a uniform compressive pressure of 20 lb/in2 being less than 18% in the case of an organic pigment and less than 13% in the case of carbon black. "Volume concentration" is defined as the ratio of the actual volume of the particles to the apparent volume of the particles, resin (if any) and air voids. The composition may be made by flocculating a suspension of pigment and flocculating a suspension or precipitating a solution of the resin either together or separately, mixing the components if prepared separately, and treating the mixture so as to soften the resin and reharden it, e.g. by heating and cooling, or by addition and removal of a solvent. Suitable pigments include phthalocyanine, azo, vat dye and lake dye pigments. Suitable resins include rosin, hydrogenated rosin, esterified rosin, polymerized rosin, polymers of vinyl alkyl benzenes, and copolymers of vinyl alkyl benzenes with alkyl methacrylates or dialkyl fumarates. Specifications 936,911, 941,386, 957,440 and 957,984 are referred to.ALSO:A solid pigment composition for the pigmentation of an organic material comprises a finely divided organic or carbon black pigment and a resinous substance which is soluble to the extent of at least 5% by weight in the organic material, the composition containing at least 60% by weight of pigment and the volume concentration of pigment in the composition under a uniform compressive pressure of 20 lbs./in.2 being less than 18% in the case of an organic pigment and less than 13% in the case of carbon black. " Volume concentration " is defined as the ratio of the actual volume of the particles to the apparent volume of the particles, resin (if any) and air voids. The composition may be made by flocculating a suspension of pigment and flocculating a suspension or precipitating a solution of the resin either together or separately, mixing the components if prepared separately, and treating the mixture so as to soften the resin and re-harden it, e.g. by heating and cooling, or by addition and removal of a solvent. Sui