| abstract |
PROBLEM TO BE SOLVED: To provide a high-performance polymer base material useful for medical devices, wherein the elution of additives is practically negligible, or at least very small. A polymer substrate is provided. Also provided is a method of impregnating an additive that is substantially insoluble in a polymer substrate with a polymer substrate using a supercritical fluid. SOLUTION: A polymer base material, an additive substantially insoluble in the polymer base material, and a low molecular weight compound polymer swelling aid soluble in a supercritical fluid and capable of impregnating the polymer base material are put in a pressure vessel, After maintaining the contact with the supercritical fluid and impregnating the polymer base material with the additive and the polymer swelling aid, flowing the supercritical fluid through the pressure vessel and allowing the polymer swelling aid to flow out and separating, the pressure in the pressure vessel is increased. A method of encapsulating an additive in a polymer substrate by reducing it. A medical polymer substrate, wherein the additive is not substantially eluted from the polymer substrate, which can be obtained by the above method. The polymer substrate is a contact lens, intraocular, ophthalmic lens material, catheter material. The additives are a dye, an ultraviolet absorber, an antiglare agent, a photochromic agent, a softener, and a hydrophilicity-imparting agent. |