Method for evaluating liquid leakage from water-absorbing resin particles

A method for evaluating liquid leakage properties of water-absorbing resin particles, the method comprising, in the following order:

• disposing a water-absorbing layer formed from the water-absorbing resin particles along an inclined plane inclined with respect to a horizontal plane;
• injecting a test solution which is in the form of liquid droplets and contains water into the water-absorbing layer exposed;
• and
• measuring a diffusion distance which is a distance in which the test solution injected into the water-absorbing layer diffuses along the inclined plane in a predetermined time,
• wherein an angle of inclination formed by the horizontal plane and the inclined plane is 25 degrees or larger and 40 degrees or smaller, and
• the water-absorbing layer fixed on an adhesive tape is formed by, dispersing 3.0 g of the water-absorbing resin particles on a rectangular adhesive surface, which has a length of 15 cm and a width of 5 cm, of the adhesive tape, and moving a stainless steel roller with a diameter of 10.5 cm and a width of 6.0 cm, which has a mass of 4.0 kg and is placed on the dispersed water-absorbing resin particles, to press the water-absorbing resin particles against the adhesive surface;
• and the water-absorbing layer is disposed along the inclined plane by bonding the adhesive tape on which the water-absorbing layer is fixed to the inclined plane.