Loading patent…
AssigneeKorea Institute of Science and Technology
InventorsChul-Joo Lee, Won-Seok Lyoo, Ick-Chan Kwon, Se-Geun Lee, Jae-Pil Kim, Moon-Hee Han
Estimating the term…
A method for separating poly(vinyl acetate) particles having various particle sizes, which have been prepared by suspension polymerization of vinyl acetate monomers, into respective microspheric poly(vinyl acetate) particles with uniform particle size distribution by the use of inorganic salt as a dispersing and antistatic agent, a method for preparing the microspheric embolic particles of a dual structure consisting of poly(vinyl acetate) core/poly(vinyl alcohol) shell by suspending the separated poly(vinyl acetate) particles into an aqueous alkali solution and subjecting the suspended particles to a heterogeneous surface saponification and the microspheric embolic particles prepared.
A method for separating poly(vinyl acetate) particles having various particle sizes, which have been prepared by suspension polymerization of vinyl acetate monomers, into individual microspheric poly(vinyl acetate) particles having a uniform particle size distribution and a polydispersity index of particle sizes of about 1.00-1.60, which comprises the steps of:
Microspheric embolic material particles of a dual structure consisting of poly(vinyl acetate) core/poly(vinyl alcohol) shell, having select particle sizes of 50-70 μm, 70-90 μm, 90-100 μm, 100-120 μm, 120-150 μm, 150-180 μm, 180-200 μm, 200-220 μm, 220-250 μm, 250-300 μm, 300-350 μm, 350-400 μm, 400-450 μm, 450-500 μm, 500-600 μm, 600-700 μm, 700-800 μm, 800-900 μm and 900-1,000 μm, and a polydispersity index of particle sizes of about 1.00-1.20, wherein the saponification degree of said poly(vinyl acetate) is about 1-99.9%, and the ratio of the inner radius of poly(vinyl acetate) core to the outer radius of poly(vinyl alcohol) shell is about 0.01-0.99.
Dependencies are inferred from the claim text.