ALEXANDRIA, Va., July 23 -- United States Patent no. 12,364,954, issued on July 22, was assigned to ASAHI KASEI MEDICAL Co. LTD. (Tokyo).
"Porous membrane" was invented by Yuzo Kayama (Tokyo), Masayasu Komuro (Tokyo) and Tetsuya Hamasaki (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A porous membrane containing a hydrophobic polymer and a water-insoluble hydrophilic polymer, the porous membrane having a dense layer in the downstream portion of filtration in the membrane, having a gradient asymmetric structure in which the average pore diameter of fine pores increases from the downstream portion of filtration toward the upstream portion of filtration, and having a gradient index of the average pore di...