ALEXANDRIA, Va., Jan. 28 -- United States Patent no. 12,533,658, issued on Jan. 27, was assigned to SUMITOMO SEIKA CHEMICALS Co. LTD. (Hyogo, Japan).
"Water-absorbent resin particles" was invented by Shiho Okazawa (Himeji, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "Water-absorbent resin particles having a gel brightness L* of 8 to 60 measured by a method including the following steps (A), (B), and (C) in this order are disclosed. (A) 0.1 g of water-absorbent resin particles are uniformly scattered in a colorless and transparent round cell for a color-difference meter having an inner diameter of 30 mm. (B) 5.0 g of ion-exchanged water is added to the round cell to cause the water-absorbent resin par...