公开(公告)号：EP4286421A1

公开(公告)日：2023-12-06

申请号：EP22746068.0

申请日：2022-01-31

申请人： Nippon Shokubai Co., Ltd.

发明人： WAKABAYASHI, Ryota ,  ADACHI, Yoshifumi ,  SATO, Mai ,  FUJINO, Shin-ichi ,  YORINO, Tsuyoshi ,  KATSUBE, Shin-ya ,  SHOBO, Yoshihiro ,  WATABE, Hiroyasu

IPC分类号： C08F6/26 ,  C08J3/12 ,  C08F220/04 ,  C08F220/20

摘要： Provided is a production method for a water-absorbing resin in which an absorption capacity without pressure of the resulting water-absorbing resin is high and a water-absorbing resin can be efficiently obtained.
The production method for a water-absorbing resin including a polymerization step of polymerizing a monomer composition containing an internal crosslinking agent and a monomer to obtain a crosslinked hydrogel polymer, and a drying step of drying the crosslinked hydrogel polymer to obtain a dry polymer, in which the crosslinked hydrogel polymer to be subjected to the drying step contains 50 ppm or more of hydrogen peroxide with respect to the solid content mass of the crosslinked hydrogel polymer, and the crosslinked hydrogel polymer is heated during the drying step so that a maximum reaching temperature of the crosslinked hydrogel polymer exceeds 160°C, and/or the dry polymer is heated after the drying step so that a maximum reaching temperature of the dry polymer exceeds 160°C.

公开(公告)号：EP3795616A1

公开(公告)日：2021-03-24

申请号：EP19803632.9

申请日：2019-05-15

申请人： Nippon Shokubai Co., Ltd.

发明人： WAKABAYASHI, Ryota ,  FUJINO, Shin-ichi ,  SATO, Mai ,  SHOBO, Yoshihiro ,  KATSUBE, Shin-ya ,  ISHIZAKI, Kunihiko

IPC分类号： C08J3/24 ,  F26B17/32

摘要： A production method includes a surface-crosslinking step of heating a mixture of a surface-crosslinking agent and a particulate dried polymer obtained with an acid group-containing unsaturated monomer as a main component. A moisture content of the particulate dried polymer is not greater than 15% by mass. A heating device including a rotary container and a plurality of heating tubes that are located within the rotary container, extend in an axial direction of the rotary container, and rotate together with the rotary container, is used in the surface-crosslinking step. The heating device includes a means for introducing and discharging a gas into and from the rotary container.

公开(公告)号：EP3795614A1

公开(公告)日：2021-03-24

申请号：EP19803772.3

申请日：2019-05-16

申请人： Nippon Shokubai Co., Ltd.

发明人： YORINO, Tsuyoshi ,  KATAKURA, Naoki ,  HAYASHI, Hiroki ,  KUMAGAI, Sumito ,  INOUE, Masahumi ,  ARAKE, Tomoyuki ,  SATO, Mai ,  WAKABAYASHI, Ryota ,  SHOBO, Yoshihiro ,  KATSUBE, Shin-ya ,  ADACHI, Yoshifumi ,  MATSUMOTO, Satoshi

IPC分类号： C08J3/12

摘要： The present invention addresses the problem of providing: a water absorbent resin powder having a reduced amount of fine powder generated and a reduced amount of fine powder recovered; and a production method for the water absorbent resin. The production method of the present invention includes a drying step and a fine powder granulation step. The drying step is for obtaining a dried polymer by drying a particulate water-containing gel crosslinked polymer which is obtained using an acid group-containing unsaturated monomer as a main component. The fine powder granulation step is for obtaining a fine powder granulated product by adding a binder and an adhesion control agent to a fine powder made of a water absorbent resin. In this production method, the obtained fine powder granulated product is recovered in the drying step or in any step before the drying step.