Patent ID: 8703859

Claim:
A method for producing a water-absorbing resin composition, comprising a mixing step for mixing water-absorbing resin particles and additive particles, wherein a mixture of the water-absorbing resin particles and the additive particles is subjected to pneumatic transportation processing in plug flow, after mixing or at the same time as mixing of the water-absorbing resin particles and the additive particles, wherein the water-absorbing resin particles comprise partially neutralized cross-linked poly(meth)acrylic acid, wherein the pneumatic transportation processing is conducted under a pressure of 0.21 to 0.8 MPa, wherein an amount of over cohesive particles, having a particle diameter of equal to or larger than 1.0 mm, in the additive particles, is equal to or smaller than 15% by weight, wherein the mixture of the water-absorbing resin particles and the additive particles contains 100 parts by weight of water-absorbing resin particles and 0.01 to 1 part by weight of additive particles, wherein percent by weight of the additive particles, (X[%]), based on 100% by weight of the water-absorbinq resin particles in the composition, and weight ratio of free additive particles, (Y), relative to the percent by weight, (X[%]), satisfy the following formula: 0.04( x ) 0.1 ≦y≦ 0.2( x ) 0.5 .