Method for measuring content of water-absorbing resin included in hygienic material, absorbent article, or intermediate product in manufacturing process thereof, and method for manufacturing hygienic material or absorbent article using the same

Abstract

Provided is a convenient, safe, and highly precise method for measuring a content of a water-absorbing resin in a hygienic material or an absorbent article. In a method for measuring a content of a water-absorbing resin, which has a water-soluble cation in the form of an ion-dissociating group, included in a hygienic material, an absorbent article, or an intermediate product in a manufacturing process thereof, A) a step for measuring an amount of a predetermined water-soluble cation in a reference sample including a known amount of the water-absorbing resin and creating a calibration curve indicating a relation between the amount of the water-absorbing resin and the amount of the predetermined water-soluble cation in the reference sample on the basis of the obtained measurement result; B) a step for measuring an amount of the predetermined water-soluble cation in a measurement sample, which includes a portion including the water-absorbing resin, of the hygienic material, the absorbent article, or the intermediate product in the manufacturing process thereof; and C) a step for calculating an amount of the water-absorbing resin in the measurement sample by the calibration curve created in the step A) from the amount of the predetermined water-soluble cation measured in the step B) are performed. The step A) and the step B) include measuring the amount of the predetermined water-soluble cation using an ion selective electrode method and include the following steps M1) and M2): M1) a step for immersing a sample in an aqueous solution including a total ionic strength adjusting agent (pre-processing step); and M2) a step for measuring the amount of the predetermined water-soluble cation in a pre-processed supernatant liquid obtained in the step M1).

Dependencies are inferred from the claim text.