Poly(meth)acrylic acid (salt)-based water-absorbing resin, and absorbent body
AssigneeNippon Shokubai Co., Ltd.
InventorsSachie Kitabata, Satoshi Matsumoto, Kanako Tsuru, Kunihiko Ishizaki
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Abstract
An object lies in providing a novel water-absorbing resin and a novel absorbent body both of which enable provision of an absorbent article that prevents swelling of a water-absorbing portion when used in a thin absorbent article. The object is achieved by providing a water-absorbing resin that is a particulate poly(meth)acrylic acid (salt)-based water-absorbing resin and has a swollen gel compressibility rate of 3% or more expressed by Formula 1: Swollen gel compressibility rate [%]=(D1−D2)/D1×100 (Formula 1), where D1 represents a thickness of a swollen gel before compression, and D2 represents a thickness of a swollen gel after compression.
Claims9
A water-absorbing resin, wherein said water-absorbing resin is a particulate poly(meth)acrylic acid (salt)-based water-absorbing resin and has a swollen gel compressibility rate of 3% or more expressed by the following (Formula 1):
- Swollen
-
- gel
-
- compressibility
-
- rate
- [
- %
- ]
- =
- (
- D
-
- 1
- -
- D
-
- 2
- )
- /
- D
-
- 1
- ×
- 100
- ,
- {
- Formula
-
- 1
- )
- where D1 is a thickness [mm] of a swollen gel layer formed by the water-absorbing resin when a measurement device which is equipped with a piston having a diameter of 59 mm and a cell having a bottom portion in a mesh form and having an inner diameter of 60 mm and in which 1.0 g of the water-absorbing resin is spread on the bottom portion has been placed in a petri dish containing a 0.9 mass % aqueous sodium chloride solution to allow the water-absorbing resin to absorb the 0.9 mass % aqueous sodium chloride solution for 5 minutes, and D2 is a thickness [mm] of the swollen gel layer formed by the water-absorbing resin after an operation of setting the measurement device on a sieve having a mesh size of 4750 μm, placing a weight on the piston so that a load of 0.7 psi is applied to the swollen gel layer, allowing the cell to stand still for 10 seconds, and then removing the weight has been repeated ten times.
Dependencies are inferred from the claim text.