Patent ID: 8323392

Claim:
An oil-in-oil emulsion comprising a first oil phase dispersed as liquid droplets in a continuous second oil phase, which liquid droplets have a number median diameter of about 1 μm to 10 μm, wherein the first oil phase comprises one or more first oils and colorant, the colorant being selected from the group consisting of a pigment, polymer, laked pigment, dye, pigment-polymer composite, dye-polymer composite, and a combination of these materials, and the second oil phase comprises one or more second oils, wherein the liquid droplets are substantially covered with a layer of hydrophobically surfaced solid particles, wherein the concentration of hydrophobically surfaced solid particles is from 5 to about 75 weight percent with respect to the first oil phase, wherein the one or more first oils comprises a liquid organic phosphate compound, the liquid organic phosphate compound being selected from the group consisting of branched or unbranched alkyl, cycloalkyl, alkylcycloalkyl, aryl, and alkaryl phosphates, in which the organic groups may be substituted or unsubstituted, wherein the second oil phase comprises one or more solvents selected from the group consisting of substantially non-polar substituted or unsubstituted C6-C20 alkanes, substituted or unsubstituted aromatic hydrocarbons, and mixtures thereof, wherein the dielectric constant at 20° C. of the first oil phase and the second oil phase, respectively, are both independently less than 25, before the addition of any solid additives to the phases, wherein the hydrophobically surfaced solid particles have an average particle size of from about 1 nm to 100 nm, and comprise inorganic particles surface treated with a hydrophobic material, and wherein the oil-in-oil emulsion further comprises a co-stabilizer that is soluble in the continuous second oil phase, for enhancing the adsorption of the hydrophobically surfaced solid particles at the interface of the first oil phase droplets and the continuous second oil phase.