Monolithic organic porous ion exchanger

An absorbent material for a liquid to be absorbed, being monolithic organic porous ion exchanger comprising:

• a continuous skeleton;
• and
• continuous pores, wherein
• the continuous skeleton is formed of an organic polymer being a hydrolysate of a crosslinked polymer of a (meth)acrylic acid ester and a polymerization monomer, the organic polymer having any one or both of a —COOH group and a —COONa group as ion-exchange groups,
• the polymerization monomer is divinylbenzene or divinylbenzene and at least one of ethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate and trimethylolpropane tri(meth)acrylate,
• the organic polymer comprises:
• a constituent unit A:
• a polymerization residue of an ethylene group, and
• a constituent unit B:
• a crosslinking polymerization residue of divinylbenzene, or
• a constituent unit A:
• a polymerization residue of an ethylene group,
• a constituent unit B:
• a crosslinking polymerization residue of divinylbenzene, and
• at least one polymerization residue of ethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate and trimethylolpropane tri(meth)acrylate,
• in the organic polymer, a proportion of the constituent unit B is 0.1 to 30% by mole based on a total amount of the constituent units, a proportion of the constituent unit B based on a total number of moles of the constituent unit A and the constituent unit B is 0.1 to 30% by mole, and a proportion of the at least one polymerization residue of ethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate and trimethylolpropane tri(meth)acrylate is 0 to 80% by mole based on a total amount of the constituent units,
• the continuous skeleton has a thickness of 0.1 to 100 μm, the continuous pores have an average diameter of 1.0 to 1000 μm, the monolithic organic porous ion exchanger has a total pore volume of 0.5 to 50.0 mL/g, and
• the monolithic organic porous ion exchanger has a total ion-exchange capacity of the —COOH group and the —COONa group per weight in a dry state of 4.0 mg equivalent/g or more.