Composition for partitioning blood components

Claim 1

A blood-partitioning composition consisting essentially of a mixture of (1) a thixotropy-imparting agent which is an inorganic solid powder having an average particle diameter of from 1 to 1,000 millimicrons, a specific surface area of at least 10 m 2 /g and a specific gravity in the range of from 1.5 to 3.0; (2) a first viscous liquid material having strong interaction with the thixotropy-imparting agent such that when the thixotropy-imparting agent is uniformly dispersed with the first viscous liquid and then centrifuged, no localization of said thixotropic agent occurs in the centrifuged liquid, said first viscous liquid having a viscosity at 20° C. of at least 200 centipoises and a specific gravity at 20° of from 0.9 to 1.2, said first material being a natural animal or vegetable oil modified with epoxy groups or a synthetic polymeric material containing carbonyl or epoxy groups in the molecule, and wherein said first material is liquid at room temperature; and (3) a second viscous liquid material having no strong interaction with the thixotropy-imparting agent such that when the thixotropy-imparting agent is uniformly dispersed with the second viscous liquid material and then centrifuged, the thixotropy-imparting agent is localized in said second viscous liquid, said second viscous liquid having good compatibility with the first viscous liquid material such that no substantial phase separation occurs upon mixing the two liquids, said second liquid material having a viscosity at 20° C. of at least 1,000 centipoises and a specific gravity at 20° C. of 0.85 to 1.20 and being a high-molecular-weight material liquid at room temperature composed substantially only of carbon and hydrogen or a high-molecular-weight material liquid at room temperature composed substantially of carbon, hydrogen and chlorine; said composition having a specific gravity at 20° C. of from 1.03 to 1.08, a viscosity at a shearing speed of 1 sec -1 of from 60,000 to 400,000 centipoises and a thixotropy coefficient of at least 1.8, the amount of said thixotropy-imparting agent being from 2 to 30 parts by weight per 100 parts by the combined weight of the first and second viscous liquid material, and the amount of said second viscous liquid material being from 20 to 600 parts by weight per 100 parts by weight of the first viscous liquid material.