MICRO-SPHERICAL EMBOLUS MATERIAL WITH DUPLEX STRUCTURE OF POLYVINYLACETATE CORE/POLYVINYL ALCOHOL SHELL AND PREPARATION METHOD THEREOF

摘要

PURPOSE: Provided is a preparation method of micro-spherical embolus material with duplex structure of polyvinylacetate (PVAc) core/polyvinyl alcohol (PVA) shell, which is used in the embolus treatment. In this treatment, the material is introduced to the blood vessels near the ailment spot where operation is not possible and it cutoffs the blood flow to cure the ailment such as hyper-vascular tumor, eases the symptoms caused by blood overflow and stops the bleeding by external wound or inflammatory bleeding of tuberculosis. Presently, polyvinyl alcohol is used as the embolus material but it brings side effect of inflammation presumably due to the sharp edges and ununiformity of the granules. CONSTITUTION: The preparation process for separating polyvinylacetate granules with uniform diameter of dispersant index of 1.00-1.6 comprises adding 0.1-100wt. parts (when PVAc wt. parts is 1) inorganic salts as dispersant and anti-static agent, wherein the salt is selected from sodium sulfate, sodium sulfite, sodium chloride, calcium sulfate and magnesium sulfate; milling PVAc granules; separating them to particles with desired size by using a standard sieve; and saponifying these granules only on the surface by suspending them in alkali aqueous solution containing NaOH, NaSO4, NaSO3 and methanol at 0 - 90deg.C so that the granules have double structure of PVAc core and PVA shell.