Method for processing substrate sheet, method for producing modified substrate sheet, substrate with graft polymer chain, and ion exchange membrane

The invention relates to a method for processing a substrate sheet, a method for producing a modified substrate sheet, a substrate with a graft polymer chain, and an ion exchange membrane. Provided is a method for processing a substrate sheet, in which a substrate sheet wound around a first core and a porous sheet wound around a second core are wound around a third core in an overlapping manner while being unwound, and a processing liquid for the substrate sheet held in the porous sheet is supplied to the substrate sheet. The base material sheet and the porous body sheet which are wound around the third core in an overlapping manner are wound out, and the porous body sheet is wound around the second core and the base material sheet is wound around the first core. 本发明涉及基材片的处理方法、改性基材片的制造方法、带接枝聚合链的基材以及离子交换膜。提供一种基材片的处理方法，其中，使卷绕于第1芯的基材片和卷绕于第2芯的多孔体片分别卷出并重叠地卷绕于第3芯，使保持于所述多孔体片的、所述基材片的处理液向所述基材片供给，使重叠地卷绕于所述第3芯的所述基材片和所述多孔体片卷出，使所述多孔体片卷绕于所述第2芯且使所述基材片卷绕于所述第1芯。