Water-absorbent resin particles, water-absorbent article, and method for manufacturing same
Water-absorbing resin particles, in which a permeation and spreading index represented by Formula (1) is 10.0 or higher, and a water absorption capacity for a physiological saline solution is 50.0 g/g or more, are disclosed. Formula (1): Permeation and spreading index=value of non-pressurization DW after 1 minute (mL/g)+artificial urine permeation speed when water-absorbing resin particles are swollen 10 times (g/min) (1).
1. Water-absorbing resin particles comprising:
a polymer particle comprising a crosslinked polymer having a monomer unit derived from an ethylenically unsaturated monomer including at least one compound selected from the group consisting of (meth)acrylic acid and a salt thereof; and
a plurality of inorganic particles disposed on a surface of the polymer particle,
wherein a proportion of a (meth)acrylic acid and a salt thereof is 70 to 100 mol % with respect to a total amount of monomer units in the crosslinked polymer,
a permeation and spreading index represented by Formula (1) is 10.0 or higher, and
a water absorption capacity for a physiological saline solution is 50.0 g/g or more,
Formula (1):
permeation and spreading index=value of non-pressurization demand wettability ( DW ) after 1 minute (mL/g)+artificial urine permeation speed when water-absorbing resin particles are swollen 10 times (g/min) (1).
2. The water-absorbing resin particles according to claim 1 ,
wherein the permeation and spreading index is 13.0 or higher.
3. The water-absorbing resin particles according to claim 1 ,
wherein the value of non-pressurization DW after 1 minute is 3.0 mL/g or more.
4. The water-absorbing resin particles according to claim 1 ,
wherein the permeation and spreading index is 14.0 or higher.
5. The water-absorbing resin particles according to claim 1 ,
wherein the permeation and spreading index is 14.0 or higher and 25.0 or lower.
6. The water-absorbing resin particles according to claim 1 ,
wherein the value of non-pressurization DW after 1 minute is 7.0 mL/g or more.
7. The water-absorbing resin particles according to claim 1 , wherein the artificial urine permeation speed when the water-absorbing resin particles are swollen 10 times is 1.0 g/min or more.
8. The water-absorbing resin particles according to claim 1 ,
the artificial urine permeation speed when water-absorbing resin particles are swollen 10 times is 1.0 g/min or more and 15.0 g/min or less.
9. The water-absorbing resin particles according to claim 1 ,
wherein a water absorption capacity of the water-absorbing resin particles for a physiological saline solution under a load is 10 to 40 mL/g.
10. The water-absorbing resin particles according to claim 1 ,
wherein a water absorption capacity of the water-absorbing resin particles for a physiological saline solution under a load is 22 to 28 mL/g.
11. The water-absorbing resin particles according to claim 1 ,
wherein a median particle size of the water-absorbing resin particles is 250 to 850 μm.
12. The water-absorbing resin particles according to claim 1 ,
wherein a median particle size of the water-absorbing resin particles is 300 to 600 μm.
13. The water-absorbing resin particles according to claim 1 ,
wherein a water absorption capacity for a physiological saline solution is 50.0 g/g or more and 70 g/g or less.
14. An absorbent article comprising:
a liquid-impermeable sheet;
an absorbent; and
a liquid-permeable sheet,
wherein the liquid-impermeable sheet, the absorbent, and the liquid-permeable sheet are disposed in this order, and
the absorbent comprises the water-absorbing resin particles according to claim 1 .
15. A method for manufacturing an absorbent article, the method comprising:
sorting out water-absorbing resin particles in which a permeation and spreading index represented by Formula (1) is 10.0 or higher, and a water absorption capacity for a physiological saline solution is 50.0 g/g or more; and
disposing an absorbent containing the sorted water-absorbing resin particles between a liquid-impermeable sheet and a liquid-permeable sheet,
wherein the water-absorbing resin particles comprise
a polymer particle containing a crosslinked polymer having a monomer unit derived from an ethylenically unsaturated monomer including at least one compound selected from the group consisting of (meth)acrylic acid and a salt thereof, and
a plurality of inorganic particles disposed on a surface of the polymer particle, and
a proportion of a (meth)acrylic acid and a salt thereof is 70 to 100 mol % with respect to a total amount of monomer units in the crosslinked polymer,
Formula (1):
permeation and spreading index=value of non-pressurization DW after 1 minute (mL/g)+artificial urine permeation speed when water-absorbing resin particles are swollen 10 times (g/min) (1).
16. The method according to claim 15 ,
wherein the value of non-pressurization DW after 1 minute of the sorted water-absorbing resin particles is 3.0 mL/g or more.