Particulate water-absorbing agent, absorbent body containing the particulate water-absorbing agent, and sanitary product including the absorbent body

Patent metadata

Field	Value
Publication number	US-2026021472-A1
Application number	US-202519339556-A
Country	US
Kind code	A1
Filing date	Sep 25, 2025
Priority date	Mar 27, 2023
Publication date	Jan 22, 2026
Grant date	—

Abstract

Provided is a particulate water-absorbing agent that can be used for producing a sanitary product capable of further reducing the re-wetting of absorbed liquid in actual use. The subject particulate water-absorbing agent is a particulate water-absorbing agent having a fluid retention capacity of more than 50 g/g when a swollen gel obtained by bringing the particulate water-absorbing agent into contact with a 0.9% aqueous sodium chloride solution for 10 minutes is let stand for 1 minute without pressure, and having a fluid retention capacity of more than 41.5 g/g when the swollen gel is let stand for 1 minute under a pressure of 4.83 kPa.

First claim

1 . A particulate water-absorbing agent, comprising a surface-crosslinked polyacrylic acid (salt)-based water-absorbent resin as a main component, the particulate water-absorbing agent satisfying Formula (A) and Formula (B) set forth below:

SRC
⁢

(
NP
)

>

50.

g
/
g

(
A
)

SRC
⁢

(

4.83

kPa

)

>

41.5

g
/
g

(
B
)

wherein the SRC (NP) is measured by a method including the following steps (a) to (c):
(a) obtaining a swollen gel by bringing the particulate water-absorbing agent (W 0 ) [g] into contact with a 0.9% aqueous sodium chloride solution (hereinafter referred to as a “test solution”) for 10 minutes with no load applied;
(b) separating the swollen gel obtained in the step (a) and the test solution;
(c) measuring a weight (W 1 ) [g] of the swollen gel separated in the step (b), and calculating the SRC (NP) of the particulate water-absorbing agent based on Formula (1) set forth below:

SRC
⁢

(
NP
)

[

g
/
g

]

=

W
1

/

W
0

,

(
1
)

the SRC (4.83 kPa) is measured by the method including the steps (a) to (c) except that, instead of the step (c), steps (c′) to (e′) described below are performed:
(c′) applying a load of 4.83 kPa to the swollen gel separated in the step (b) for 1 minute;
(d′) removing an exudate exuded from the swollen gel in the step (c′); and
(e′) measuring a weight (W 2 ) [g] of the swollen gel obtained in the step (d′), and calculating the SRC (4.83 kPa) based on Formula (2) set forth below:

SRC
⁢

(

4.83

kPa

)

[

g
/
g

]

=

W
2

/

W
0

.

(
2
)

2 . The particulate water-absorbing agent according to claim 1 , wherein a value of the SRC (4.83 kPa) in Formula (B) is more than 42 g/g.

3 . The particulate water-absorbing agent according to claim 1 , wherein a value of the SRC (NP) in Formula (A) is more than 54.

4 . The particulate water-absorbing agent according to claim 1 , wherein a water absorption speed (Vortex method) is 40 seconds or less.

5 . The particulate water-absorbing agent according to claim 1 , wherein a surface tension (STR) is 66 mN/m or more.

6 . The particulate water-absorbing agent according to claim 1 , wherein a centrifuge retention capacity (CRC) is 35 g/g or more.

7 . The particulate water-absorbing agent according to claim 6 , wherein a centrifuge retention capacity (CRC) is 40 g/g or more.

8 . The particulate water-absorbing agent according to claim 1 , further comprising one or more selected from the group consisting of inorganic colloidal particles, water-insoluble inorganic particles, and a water-soluble polyvalent metal cation-containing compound.

9 . An absorbent body, comprising the particulate water-absorbing agent according to claim 1 .

10 . A sanitary product, comprising the absorbent body according to claim 9 .

Assignees

• Nippon Catalytic Chem Ind

Inventors

• Onishi Keita
• Oga Yosuke
• Shimizu Ryo
• Ikeuchi Hiroyuki
• ENOKIDA Yusuke
• Tamaki Mariko
• Torii Kazushi

Classifications

• B01J20/267 Primary

  Cross-linked polymers · CPC title

• B01J20/261

  obtained by reactions only involving carbon to carbon unsaturated bonds (macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F) · CPC title

• A61F13/49

  specially adapted to be worn around the waist, e.g. diapers, nappies · CPC title

• B01J20/28016 Primary

  Particle form · CPC title

• B01J20/28047

  Gels · CPC title