	US 12,235,580 B2
	Method for producing a lithography coating film forming-composition
Takumi Oya, Toyama (JP); Hiroki Yamaguchi, Toyama (JP); and Suguru Sassa, Toyama (JP)
Assigned to NISSAN CHEMICAL CORPORATION, Tokyo (JP)
Filed by NISSAN CHEMICAL CORPORATION, Tokyo (JP)
Filed on Jun. 11, 2021, as Appl. No. 17/345,631.
Claims priority of application No. 2020-119163 (JP), filed on Jul. 10, 2020.
Prior Publication US 2022/0011671 A1, Jan. 13, 2022
Int. Cl. G03F 7/11 (2006.01); B01J 39/20 (2006.01); B01J 41/13 (2017.01); C09D 125/18 (2006.01); C09D 163/00 (2006.01)

CPC G03F 7/11 (2013.01) [B01J 39/20 (2013.01); B01J 41/13 (2017.01); C09D 125/18 (2013.01); C09D 163/00 (2013.01)]

9 Claims

1. A method for producing an ion-exchange resin having a water content of 5% by weight or less, comprising passing an organic solvent having a water content of 150 ppm or less through a system including a column of an ion-exchange resin precursor having a water content of 40% by weight or more, with only a single frequency of passing the organic solvent through the column, and then removing the organic solvent remaining in the system from the system by blowing nitrogen gas,

wherein a dehydration efficiency defined by the following equation is 5 or more:

dehydration efficiency=dehydration rate (%)/[weight of the organic solvent used per unit weight of the ion-exchange resin precursor (kg/kg)×washing time (h)], and

wherein, in the passing of the organic solvent, the organic solvent is passed in a rate of passing of 3 (h⁻¹) or less, in terms of a space velocity based on an ion-exchange resin-filled layer volume.