PROBLEM TO BE SOLVED: To provide a manufacturing method of a polyvinylpyrrolidone polymer capable of manufacturing the polyvinylpyrrolidone polymer easy to be pulverized and excellent in handleability.SOLUTION: There is provided a manufacturing method of a polyvinylpyrrolidone polymer by a precipitation polymerization method, including a drop process for dropping a monomer component containing N-vinylpyrrolidone and a polymerization initiator separately into a reaction medium, in which an amount of the polymerization initiator in an initial reaction medium before the drop process is 30 mass% or less of all amount of the polymerization initiator, and the polymerization initiator is dropped for longer than drop time of the monomer component in the drop process.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】粉砕が容易で、取扱性に優れたポリビニルピロリドン重合体を製造できるポリビニルピロリドン重合体の製造方法を提供すること。【解決手段】沈殿重合法によるポリビニルピロリドン重合体の製造方法であって、Ｎ－ビニルピロリドンを含むモノマー成分と、重合開始剤と、を別個に反応媒体中に滴下する滴下工程を含み、該滴下工程前の初期反応媒体中の該重合開始剤量は、反応に使用する該重合開始剤全量の３０質量％以下であり、該滴下工程において、該重合開始剤を該モノマー成分の滴下時間より長い時間で滴下する、ポリビニルピロリドン重合体の製造方法を提供する。【選択図】図１
