Patent ID: 8647528

Claim:
A water absorbing agent comprising: a water absorbing resin (A); and a polymer (B) being a polyamine polymer having a hydroxyl group on a main chain, said water absorbing resin (A) being a cross-linked polymer of polyacrylic acid and/or a salt thereof, said polymer (B) (i) being obtainable by reacting an amine and an epihalohydrin, which are monomers and whose amounts in total with respect to the whole amount of the polymer (B) are 100 to 60 mass %, (ii) containing dialkylamine, as the amine, whose amount respect to the whole amount of the amine is not less than 50 mol % and not more than 100 mol %, and (iii) having a weight average molecular weight of 40,000 dalton to 500,000 dalton, the polymer (B) with respect to 100 parts by mass of the water absorbing resin (A) being 0.01 to 10 parts by mass, said water absorbing agent having a yellowness index (YI) of not more than 30 in the Hunter's Lab color system when measured by spectral colorimeter after a 7-day exposure to an atmosphere at 70±1° C. and 65±1% relative humidity.