METHOD FOR OBTAINING A POLYMER IN A SOLUTION

摘要

The invention relates to a method for obtaining at least one polymer in a solution in a solvent by precipitation by means of a non-solvent gradually introduced into the solution in order to form a precipitation medium, wherein a) during the course of the introduction of the non-solvent into the precipitation medium, phase separation initially occurs (into a continuous phase which is rich in solvent wherein the polymer is dissolved and into a dispersed phase consisting of drops which are rich in non-solvent); and subsequently, phase inversion occurs (the continuous phase becomes a phase which is rich in non-solvent and the dispersed phase becomes rich in solvent containing the dissolved polymer; b) the non-solvent is initially introduced into the precipitation medium in an exclusively liquid form whereby the amount thereof (Q') is not zero but lower than the required amount (Q) for phase inversion, and it is subsequently introduced into the precipitation medium in an at least partial manner in the form of vapor.